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9,500 | Peripheral and cerebral atherothrombosis and cardiovascular events in different vascular territories: insights from the Framingham Study. | Major risk factors for clinical atherosclerosis include dyslipidemia, hypertension, glucose intolerance, adiposity, cigarette smoking, hemostatic factors, inflammatory markers, and sedentary lifestyle. Sets of some of these and evidence of vascular damage such as left ventricular hypertrophy and atrial fibrillation are used to formulate multivariable risk profiles for peripheral artery disease and stroke. These global risk formulations facilitate office estimation of the risk of these disabling diseases, which often indicate diffuse systemic atherosclerosis. Because predisposing risk factors usually cluster, and the risk each imposes varies widely, global risk assessment is a necessity, especially now that average risk factor levels are recommended for treatment. Novel risk factors deserve attention, but the standard cardiovascular risk factors account for as much as 85% of the cardiovascular disease arising within the population. Further improvement in detection, evaluation, and control of the major risk factors by implementation of guidelines for primary and secondary prevention of stroke and peripheral artery disease is needed, particularly in the high-risk segment of the population. |
9,501 | Effect of oligomer procyanidins on reperfusion arrhythmias and lactate dehydrogenase release in the isolated rat heart. | The antiarrhythmic effect of an oral 3-week-pretreatment with oligomer procyanidins derived from Vitis vinifera was investigated on the isolated perfused heart after global no-flow ischemia (procyanidin-treated group: n = 9, control group: n = 13). Hearts were perfused with a modified Krebs-Henseleit solution in which the K+ content was reduced to 3.0 mmol/l in order to lower the fibrillation threshold. Monophasic action potentials in addition to ECG were recorded. The durations of ischemia and reperfusion were 20 and 30 min, respectively. Arrhythmias including ventricular fibrillation (VF), ventricular tachycardia (VT), flutter (Fl) and bradycardia were evaluated. During the reperfusion, irreversible VF occurred in most of control hearts. The incidence of VF (percentage of the hearts in which VF occurred) was lowered by oligomer procyanidins from 84.6 to 55.6 %, and the duration of the episodes of VF (expressed as percentage relative to the total duration) was significantly shortened from 76.1 +/- 27.9 % to 36.6 +/- 40.6 % (p = 0.036). Simultaneously, the percentage of duration of normal sinus rhythm (NSR) increased from 19.5 +/- 30.3 % to 46.2 +/- 35.9 % (n.s.). VF occuring in the procyanidin-treated hearts could be reversed in two hearts within few minutes to a stage of "reversible arrhythmias" consisting of short episodes (1 to 60 s) of either Fl or VT or bradycardia or NSR alternating with each other. LDH (lactate dehydrogenase) release in the first drops appearing from the reperfused heart was significantly reduced in the procyanidin-treated rats (66.7 +/- 36.2 mU/min, n = 8) in comparison to controls (159.7 +/- 79.0 mU/min, n = 10; p = 0.010). These results demonstrate an antiarrhythmic and cytoprotective effect of oral pretreatment with oligomer procyanidins under the given experimental conditions. |
9,502 | Natural history and predictors of outcome in patients with concomitant functional mitral regurgitation at the time of aortic valve replacement. | Concomitant functional mitral regurgitation (FMR) in patients undergoing aortic valve replacement (AVR) is frequently not corrected because it may improve after AVR; however, data supporting this assumption are sparse. We ascertained the impact of clinical and echocardiographic parameters on the outcome of patients with or without concomitant FMR at the time of AVR.</AbstractText>Clinical and echocardiographic follow-up was performed on 848 patients who underwent AVR after 1990. Risk factors for mortality and a composite outcome of heart failure (CHF) symptoms, CHF death, or subsequent mitral repair or replacement, were examined with bootstrapped Cox proportional hazard models. Follow-up was 4591 patient-years (mean 5.4+/-3.4 years; maximum 14.2 years). FMR > or = 2+ had no independent adverse effect on survival in patients with aortic stenosis (AS) or insufficiency (AI). However, AS patients with FMR > or = 2+ and 1 additional risk factor (left atrial diameter >5 cm, preoperative peak aortic valve gradient <60 mm Hg, or atrial fibrillation) were at increased risk for the composite outcome (hazard ratio [HR]: 2.7; P=0.004). AI patients with FMR > or = 2+ and a left ventricular end-systolic diameter <45 mm were also at risk (HR: 4.0; P=0.02). Clinical risk factors in the AS and AI subgroups were associated with an increased likelihood of mitral regurgitation > or = 2+ at 18 months postoperatively.</AbstractText>AS patients with FMR > or = 2+ and a left atrial diameter >5 cm, preoperative peak aortic valve gradient <60 mm Hg, or atrial fibrillation have a significantly higher risk of CHF and persistent mitral regurgitation after AVR than other AS patients. AI patients with FMR > or = 2+ and a left ventricular end-systolic diameter <45 mm preoperatively are also at increased risk. Others fare well after AVR.</AbstractText> |
9,503 | Multislice computed tomography accurately quantifies left atrial size and function after the MAZE procedure. | Although the MAZE procedure allows for the recovery of sinus rhythm and left atrial (LA) mechanical function in the great majority of patients with chronic atrial fibrillation (AF), the effects of MAZE on the precise LA geometry and wall motion remain to be elucidated. We hypothesized that LA size and mechanical function in patients with chronic AF and mitral valvular disease are well restored after MAZE.</AbstractText>We studied 14 patients (MAZE group: mean+/-SD age, 63.9+/-8.6 years; 8 men and 6 women) who underwent MAZE for chronic AF and mitral valve surgery and 10 patients with sinus rhythm (coronary artery bypass graft [CABG] group: age, 70.0+/-7.9 years; 5 men and 5 women) who underwent CABG at Takeda Hospital between February 2002 and September 2005. MAZE was conducted by the endocardial application of radiofrequency ablation with a temperature-controlled multipolar radiofrequency catheter. LA volume and booster function were quantitatively evaluated by multislice computed tomography at 17.9+/-10.0 months (MAZE group) and 15.3+/-13.6 months (CABG group) postoperatively. All patients with MAZE were free of AF and other atrial arrhythmias during the follow-up period. In the CABG group, LA maximal and minimal volumes and ejection fraction were 109+/-12 mL, 82+/-11 mL, and 26+/-10%, respectively. In the MAZE group, LA maximal volume was 139+/-17 mL (P=0.187 versus CABG), and LA minimal volume was 121+/-16 mL (P=0.082 versus CABG), with an ejection fraction of 15+/-7% (P=0.004 versus CABG). In both groups, all parts of the LA wall contracted toward the geometric center of the LA. The extent of wall motion was significantly worse in the MAZE group compared with the CABG group. In both groups, LA booster function was inversely correlated with LA maximal volume.</AbstractText>MAZE with radiofrequency ablation is safe and effective for the restoration of sinus rhythm in patients with chronic AF and mitral valve disease. However, chronic AF associated with mitral valve disease deteriorates LA mechanical function diffusely throughout the LA wall. Further studies with the use of multislice computed tomography are needed to sequentially evaluate LA function after MAZE in patients with and without mitral valve surgery.</AbstractText> |
9,504 | Mitral valve repair versus revascularization alone in the treatment of ischemic mitral regurgitation. | For patients with ischemic mitral regurgitation (MR), it is not clear whether adjunctive mitral valve (MV) repair at the time of coronary artery bypass graft surgery (CABG) is beneficial. We sought to test the hypothesis that MV repair with CABG is superior to CABG alone in improving MR without increasing operative or long-term mortality.</AbstractText>A total of 107 consecutive patients with moderate or severe ischemic MR, as determined by preoperative echocardiography, underwent CABG with concomitant MV repair (repair group, n=50) or CABG only (CABG group, n=57). Degree of MR was graded as none, mild, moderate, or severe by the proximal isovelocity surface area method. The groups were similar with respect to age, gender, baseline New York Heart Association class, ejection fraction, and number of bypass grafts. The repair group had a higher percentage of patients with atrial fibrillation or severe MR than the CABG group. The operative mortality was significantly higher for the repair group (12%) than the CABG group (2%), whereas the 5-year actuarial survival rate of the 2 groups was similar (88%+/-5% versus 87%+/-6%). On multivariate logistic regression analysis, older age, higher New York Heart Association class, and atrial fibrillation were independent predictors of operative mortality (P<0.05). Among patients with severe MR, ischemic MR was improved in all patients of the repair group and in 67% of patients in the CABG group (P<0.001), whereas improvement rates in patients with moderate MR were similar in the 2 groups (75% versus 67%, P=NS).</AbstractText>Although MV repair appears to be more effective at reducing ischemic functional MR, CABG alone may be a preferable treatment option for patients with moderate MR and high operative risk factors such as old age or atrial fibrillation.</AbstractText> |
9,505 | Effects of the gap junction modifier rotigaptide (ZP123) on atrial conduction and vulnerability to atrial fibrillation. | Altered conduction is associated with increased atrial fibrillation (AF) vulnerability in canine models of chronic mitral regurgitation (MR) and heart failure (HF). Rotigaptide (ZP123) augments gap junction conductance, improving cell-to-cell coupling. We studied the effects of rotigaptide on atrial conduction and AF vulnerability in the canine MR and HF models.</AbstractText>Twenty-one dogs in 3 groups were studied: control (n=7), chronic MR induced by mitral avulsion (n=7), and HF induced by ventricular tachypacing (n=7). Epicardial mapping of both atria was performed with a 512-electrode array at baseline and at increasing rotigaptide doses (10, 50, and 200 nmol/L). Conduction velocity increased in both atria in control animals and MR animals (maximum percentage increase: 24+/-5%, 38+/-6% [P<0.001, <0.001] in the left atrium and 19+/-9%, 18+/-3% [P<0.001, <0.001] in the right atrium). Conduction velocity did not change in the left atrium of the HF group and increased minimally in the right atrium (3+/-3%, 17+/-5% [P=NS, P=0.001]). AF duration was increased at baseline in MR and HF animals (control: 16+/-25 seconds, MR: 786+/-764 seconds, HF: 883+/-684 seconds; P=0.013). At 50 nmol/L of rotigaptide, duration of AF markedly decreased in the MR animals (96% reduction, P<0.001), reducing AF duration to that of control animals (control: 9+/-11 seconds, MR: 14+/-16 seconds, HF: 1622+/-355 seconds; P=0.04).</AbstractText>Gap junction modulation with rotigaptide reduces AF vulnerability in a canine MR model of AF to a level similar to control animals but does not affect AF vulnerability in the canine HF model. This may be a novel therapeutic target in some forms of AF.</AbstractText> |
9,506 | Effect of amiodarone and sotalol on ventricular defibrillation threshold: the optimal pharmacological therapy in cardioverter defibrillator patients (OPTIC) trial. | Many patients with implanted cardioverter defibrillators (ICDs) receive adjunctive antiarrhythmic drug therapy, most commonly amiodarone or sotalol. The effects of these drugs on defibrillation energy requirements have not been previously assessed in a randomized controlled trial.</AbstractText>The Optimal Pharmacological Therapy in Cardioverter Defibrillator Patients (OPTIC) trial was a randomized clinical trial evaluating the efficacy of amiodarone plus beta-blocker and sotalol versus beta-blocker alone for reduction of ICD shocks. Within OPTIC, a prospectively designed substudy evaluated the effects of the 3 treatment arms on defibrillation energy requirements. Defibrillation thresholds (DFTs) were measured (binary step-down protocol) at baseline and again after 8 to 12 weeks of therapy in 94 patients, of whom 29 were randomized to receive beta-blocker therapy (control group), 35 to amiodarone plus beta-blocker, and 30 to sotalol. In the control group, the mean DFT decreased from 8.77+/-5.15 J at baseline to 7.13+/-3.43 J (P=0.027); in the amiodarone group, DFT increased from 8.53+/-4.29 to 9.82+/-5.84 J (P=0.091). In the sotalol group, DFT decreased from 8.09+/-4.81 to 7.20+/-5.30 J (P=0.21). DFT changes in the beta-blocker and the amiodarone group were significantly different (P=0.006). In all patients, adequate safety margins for defibrillation were maintained. No clinical variable predicted baseline DFT or changes in DFT on therapy.</AbstractText>Although amiodarone increased DFT, the effect size with modern ICD systems is very small. Therefore, DFT reassessment after the institution of antiarrhythmic drug therapy with amiodarone or sotalol is not routinely required.</AbstractText> |
9,507 | Detection of T-wave alternans using an implantable cardioverter-defibrillator. | Microvolt T-wave alternans (TWA) increases acutely prior to ventricular tachycardia (VT) or ventricular fibrillation (VF) in computer simulations and animal models, suggesting that TWA may provide a warning for VT/VF in patients with an implantable cardioverter-defibrillator (ICD).</AbstractText>The purposes of this study were to develop a method for analyzing TWA recorded from ICD electrograms (EGMs) and to evaluate the degree of concordance between EGM TWA and TWA recorded from the surface ECG.</AbstractText>We developed a software program to measure EGM TWA in the frequency domain and then used simulated EGMs to determine the effects of ICD signal processing, electrical noise, and variation in the EGM fiducial point on the recorded amplitude and K score (signal-to-noise ratio) of TWA. We then applied this method to analyze TWA simultaneously using both surface ECGs and ICD EGMs during incremental pacing in 25 ICD patients. Pacing modes and EGM sources were varied in repeated trials. EGMs with dynamic range adjusted to achieve a large T wave were telemetered to a digital Holter recorder and measured offline. ECG TWA was analyzed using a commercial system. A positive (+) ECG test had sustained alternans >or=1.9 microV with K score >or=3. Stored EGMs were reviewed for VT/VF during a 6-month follow-up period.</AbstractText>Simulations demonstrated that the EGM method accurately identified TWA >or=10 microV. Overall, 10 (40%) patients had at least one ECG TWA+ test and 15 patients (60%) had no ECG TWA+ tests. The maximum value of TWA was greater in EGMs than in ECGs (median 64 microV vs 2.2 microV, P <.0001). EGM TWA was greater in ECG TWA+ tests than in ECG TWA- tests (169 +/- 175 microV vs 71 +/- 61 microV, P <.001). Using a sustained EGM TWA threshold of 30 microV, EGM TWA was concordant with ECG TWA in 63 (84%) of 75 analyzed tests (P <.0001) and predicted ECG TWA results with 85% sensitivity and 84% specificity. Both ECG and EGM TWA predicted VT/VF during follow-up (ECG: P = .006; EGM: P = .035).</AbstractText>The amplitude of TWA is at least 10 times greater on ICD EGMs than on surface ECGs. EGM and ECG TWA have substantial concordance and comparable predictive value for spontaneous VT/VF. These observations support the hypothesis that ECG and EGM TWA detect the same electrical alternans phenomenon.</AbstractText> |
9,508 | Delayed paced ventricular activation in the long QT syndrome is associated with ventricular fibrillation. | LQTS may cause sudden cardiac death (SCD), but the mechanisms linking gene mutations to ventricular fibrillation (VF) are unclear.</AbstractText>To determine whether ventricular activation delays in congenital long QT syndrome (LQTS) are associated with VF and to describe these delays clinically by measuring activation through ventricular myocardium after a premature extrastimulus.</AbstractText>Forty-six patients with LQTS, including 16 with VF (LQTS VF) were investigated, and the results were compared with those from 24 patients with hypertrophic cardiomyopathy and VF (HCM VF). Electrograms in response to premature stimuli were analyzed for increases in electrogram duration (DeltaED) and the S1S2 coupling intervals at which electrogram latency starts to increase (S1S2(delay)). Two piecewise continuous straight line segments were fitted to the last electrogram deflection as a function of S1S2 interval in the LQTS and HCM VF populations, and the difference in their gradient (alpha) was taken as an index of the abruptness of the onset of this delay.</AbstractText>Thirteen LQTS VF and six LQTS non-VF patients had values of DeltaED and S1S2(delay) comparable to those in HCM VF patients, while the remainder (three LQTS VF and 24 LQTS non-VF) had lower values (P<.001). There was only a weak correlation between delay and the corrected QT interval. The HCM and LQTS VF patients could be separated by the value of alpha (P<.01), with the LQTS patients having a more abrupt onset of delay.</AbstractText>Large delays in ventricular activation after an extrastimulus occur in patients with the LQTS, especially those with VF. The change in delay is abrupt in the LQTS, indicating sudden block to activation creating a dynamic substrate for arrhythmogenesis.</AbstractText> |
9,509 | Sudden cardiac arrest in intercollegiate athletes: detailed analysis and outcomes of resuscitation in nine cases. | Public access defibrillation programs have demonstrated a survival benefit in persons with out-of-hospital cardiac arrest. However, little is known about the effectiveness of early defibrillation in young competitive athletes with sudden cardiac arrest (SCA).</AbstractText>The purpose of this study was to investigate the details and outcomes of resuscitation in a cohort of intercollegiate athletes with SCA.</AbstractText>Nine cases of SCA in intercollegiate athletes occurring between 1999 and 2005 were identified through prior research and public media. A detailed questionnaire was completed by the certified athletic trainer involved in the resuscitation, and direct phone follow-up was achieved in every case.</AbstractText>Nine intercollegiate athletes with SCA (4 basketball, 2 football, 2 lacrosse, and 1 swimming) had an average age of 21 years (range 18-30 years). All 9 athletes had a witnessed collapse, 7 occurred during practice, 1 during competition, and 1 during organized weight training. Cardiopulmonary resuscitation (CPR) was initiated within 30 seconds after cardiac arrest in 6 cases and by 1 minute in 2 additional cases. An automated external defibrillator (AED) was provided by an athletic trainer in 5 cases and by arriving emergency medical services (EMS) in 4 cases. The initial cardiac rhythm was confirmed or suspected ventricular fibrillation in 7 athletes, pulseless idioventricular rhythm in 1 case, and unknown in 1 case. In 7 cases a shock was deployed, with an average time from cardiac arrest to defibrillation of 3.1 minutes (range 1-7.5 minutes). The average time from arrest to defibrillation decreased significantly if an AED was provided by an athletic trainer as compared with the responding EMS (1.6 vs 5.2 minutes; P = .046). Eight of the 9 athletes died. The underlying cause of sudden cardiac death was hypertrophic cardiomyopathy in 5, commotio cordis in 2, and myocardial infarction in 1. Diagnostic studies in the survivor demonstrated no structural heart disease or precise cause of SCA.</AbstractText>Despite witnessed collapse, immediate CPR, and prompt AED use in most cases, early defibrillation showed limited success, and survival was less than expected in this small cohort of intercollegiate athletes. More research is needed to determine the effectiveness of early defibrillation and factors that affect survival in young athletes with SCA.</AbstractText> |
9,510 | A single moving dipole model of ventricular depolarization. | Modeling abnormal depolarization of the ventricles may provide a means to localize sites of arrhythmia foci from the body surface recordings. In this paper, we present a single moving dipole (SMD) model of the ventricular depolarization. The model can reproduce characteristic QRS patterns comparable to the clinical recordings when it is located in an inhomogeneous torso model. Our approach involves estimating a series of dipole moments based on vectocardiograms and estimating trajectories based on the three-dimensional isochrone of the ventricular activation. The patterns of body surface potential isochrones are consistent with those from previous studies. The SMD model was also used to simulate posterior wall infarction, which matched the criteria for this diagnosis. In conclusion, our SMD model provided a base for further ventricular depolarization studies and this equivalent dipole approach might be useful in investigating ventricular arrhythmias and their site of origin. |
9,511 | The utility of implantable loop recorders for diagnosing unexplained syncope in 100 consecutive patients: five-year, single-center experience. | The purpose of this study was to retrospectively review the 5-year experience of a university hospital with implantable loop recorders (ILR) for the diagnosis of recurrent, unexplained syncope or presyncope.</AbstractText>One hundred patients with syncope or presyncope of unknown etiology (negative tilt-table test, electrophysiology study and neurologic workup) underwent prolonged monitoring with an ILR from March 2000 to December 2004. All implants were performed using a first-generation (manual activation) or second-generation (manual plus automatic activation) ILR.</AbstractText>One hundred patients (70 women, 30 men) with a mean age of 68 +/- 18 years received the ILR. Twenty-three patients had coronary artery disease; 2 patients had dilated cardiomyopathy. Ten patients received a first-generation ILR, and 90 patients received a second-generation ILR. After 9 +/- 8 months' follow up, ILR interrogation identified an arrhythmogenic etiology to the syncope/presyncope in 45 patients with 55 events. Eight patients had a diagnosis by ILR less than 2 months from the date of implantation. Twenty-six patients had documented symptomatic bradycardia (asystole, sinus pauses, atrial fibrillation with long pauses); 11 patients had episodes of sinus tachycardia with heart rates of 130 to 140 beats/minute; 2 patients had atrial tachycardia; 5 patients had multiple episodes of nonsustained ventricular tachycardia (NSVT); 1 patient had sustained ventricular tachycardia, and 4 patients had paroxysmal supraventricular tachycardia. All arrhythmias were treated successfully by pacemaker/ICD implantation, radiofrequency catheter ablation and/or medications. One patient had seizure activity, which was detected by ILR as high-frequency noise. Two patients failed to activate their device, as it was a first-generation device.</AbstractText>Five-year experience with the ILR in 100 consecutive patients confirms the utility of this device in the diagnosis of recurrent, infrequent, unexplained syncope or presyncope. It helped diagnose 45% of patients with unexplained syncope with negative electrophysiologic and neurologic workup. Most of these patients had an arrhythmogenic etiology to their syncope. Medical therapy, device therapy, and/or catheter ablation helped successfully treat all patients with an arrhythmogenic etiology detected by ILR.</AbstractText> |
9,512 | Successful parental use of an automated external defibrillator for an infant with long-QT syndrome. | Congenital long-QT syndrome with 2:1 atrioventricular block presenting in the perinatal period is rare, has a poor prognosis, and leads to high risk for lethal ventricular arrhythmic events. An implantable cardioverter-defibrillator seems to be the most effective treatment in the prevention of arrhythmic sudden cardiac death in patients with long-QT syndrome. Technical limitations and risks associated with implantable cardioverter-defibrillators in asymptomatic infants is considered too great to justify use for primary prophylaxis against sudden cardiac death. In this case report we describe the first successful parental use of an automated external defibrillator prescribed for primary prophylaxis against sudden cardiac death in an infant with long-QT syndrome. |
9,513 | Management of cardiovascular risk in patients receiving calcineurin inhibitors--a case report. | Cardiovascular disease is the main cause of death after renal transplantation. There are few trials evaluating the efficacy of prevention strategies in renal transplant patients on major adverse cardiac events (MACE) and cardiovascular mortality. However, there is general agreement that active prevention strategies can significantly decrease cardiovascular mortality after renal transplantation. Here, we present the case of a 52-year-old male patient who received a first kidney transplant in 1993. He showed a small fixed perfusion defect on thallium scintigraphy before transplant. He was admitted at 13 months due to an antero-lateral myocardial infarction that was complicated with ventricular fibrillation. Despite anti-coagulation with acenocumarol, treatment with statins and angiotensin II receptor blocking agents and an excellent preservation of renal function, the patient presented with a second episode of myocardial infarction at 9 years post-transplant. This case report is discussed in order to highlight the way in which attitudes have been modified in the past decade in order to systematically pursue an early diagnosis of pre-existing coronary artery disease, aggressively treat MACE and actively decrease cardiovascular risk in transplant patients, using all available efficacious treatments as well as individualizing immunosuppression to prolong not only graft but also patient survival. |
9,514 | External reshaping of the left ventricle in off-pump surgery. | : Dyskinetic areas of the lateral and inferior left ventricular (LV) wall are frequently encountered in patients with coronary artery disease. In clinical practice, all of the techniques described for the restoration of shape and function of the LV require cardiopulmonary bypass. A new technique of LV external reshaping that aims to obtain a near-normal ventricular conical shape is described. This technique is performed during an off-pump coronary artery bypass graft (CABG) operation. It is used mainly on the inferior and lateral walls of the ventricle, but also on the anterolateral wall when warranted. This technique can be considered an alternative to classic aneurysmectomy in high-risk cases.</AbstractText>: All patients underwent total arterial revascularization without aortic manipulation. Intraoperative transesophageal echocardiography was used in all cases to define the dilated akinetic/dyskinetic area. This area was effectively plicated using interrupted mattress sutures reinforced with Teflon felt or pericardial strips. This technique allows near normalization of the geometry of the ventricle and LV end-diastolic volume reduction. In cases of preexisting mitral regurgitation (MR), a reduction of the MR was observed after lateral wall restoration. From September 2002 to April 2005, the external reshaping technique was applied on 56 cases among 949 off-pump CABG cases (5.9%). A detailed transthoracic echocardiogram was obtained preoperatively. The mean ejection fraction of all enrolled patients was 31.2 ± 7%. The location of the plication was: lateral wall in 22, inferior wall in 16, and anterolateral wall in 18. The average number of coronary anastomoses was 2.6. Twelve patients were found to have 2-3+ MR. All patients were followed up during a period of 35 months.</AbstractText>: One patient died due to severe right ventricular dysfunction. Seven patients developed atrial fibrillation, and one had ventricular tachycardia. During the follow-up period, we observed a reduction of left ventricular end-diastolic diameter and a parallel augmentation of ejection fraction (mean 42.2 ± 4%). The ventricular cavity's architecture was normalized. Among the 12 patients with MR, an improvement of regurgitation was noted in 10 (from 2-3+ to 1-2+). One patient died during the follow-up period, and 1 patient required reoperation due to persistent severe MR.</AbstractText>: The external reshaping of the LV during beating heart surgery is technically feasible, has promising results, and can be performed without major complications.</AbstractText> |
9,515 | Inferior wall myocardial infarction with or without right ventricular involvement--treatment and in-hospital course. | Right ventricular infarction (RVI) is most commonly associated with inferior wall infarction (20-50% of cases). Clinical presentation of RVI may vary.</AbstractText>Assessment of outcome and clinical course of myocardial infarction in patients with inferior wall myocardial infarction with or without RVI. Additionally, risk stratification was attempted in the above-mentioned groups of patients.</AbstractText>The analysis involved 181 consecutive patients (pts) with inferior wall myocardial infarction hospitalised between 1 July 2000 and 1 July 2002.</AbstractText>Nineteen in-hospital deaths were noted in the study group (mortality 10.5%), reinfarction occurred in 6 (3.3%) pts, ischaemic stroke in 1 (0.6%) patient, and 2 (1.1%) pts had transient ischaemic attack. Cardiogenic shock occurred in 20 (11.0%) pts , ventricular fibrillation in 15 (8.3%) pts, and pulmonary oedema in 9 (4.9%) pts. In the subgroup of 161 pts without cardiogenic shock 8 (4.9%) pts died. Thrombolytic therapy was administered in 96 (53%) subjects. Isolated inferior wall myocardial infarction was diagnosed in 94 (51.9%) of 181 pts and RVI in 65 (35.9%) pts. Mortality rate in the RVI group was significantly higher than in inferior wall myocardial infarction without RVI and was 18.5% vs 2.12% (p=0.0003), respectively (excluding patients with cardiogenic shock: 11.1% vs 1.2%, respectively; p=0.016). In patients with RVI aged above 70 years, the mortality rate was significantly higher than in younger patients (32% vs 10%, p=0.002). In a subgroup with RVI treated with thrombolysis mortality was considerably higher in subjects aged >70 years compared to patients below 70 years (38.5% vs 7.7%, p=0.017).</AbstractText>RVI is associated with worse prognosis and increased number of in-hospital complications. Older patients aged >70 years have definitely poorer prognosis. Thrombolytic therapy in a subgroup of older patients with RVI remains ineffective.</AbstractText> |
9,516 | Reduced survival following resuscitation in patients with documented clinically abnormal observations prior to in-hospital cardiac arrest. | Patients suffering in-hospital cardiac arrest (IHCA) often have abnormal clinical observations documented prior to the arrest. This study assesses whether these patients have a less favourable outcome following IHCA.</AbstractText>A multiple logistic regression analysis of retrospectively collected hospital chart data and prospectively collected Utstein style resuscitation data. Patients were defined as having abnormal clinical observations if they had one of the following documented 8 h before the arrest: systolic arterial blood pressure below 90 or over 200, pulse rate below 40 or over 140 beats per min or oxygen saturation below 90% with or without supplemental oxygen. Pre-arrest variables included were: age, sex and functional status, co-morbidities, reason for hospital admission, days in the hospital before the arrest, witnessed or un-witnessed arrest, arrest occurring outside regular working hours, monitored or non-monitored ward, whether basic life support was performed before the arrival of the resuscitation team, delay to arrival of resuscitation team and initial rhythm.</AbstractText>Survival to hospital discharge of patients with clinically abnormal observations was 9% and among those without 18% (p=0.037). Independent pre-arrest predictors of survival were: un-witnessed arrest (odds ratio [OR] 0.1, confidence interval (CI) 0.01-0.8), initial rhythm other than ventricular fibrillation or ventricular tachycardia (OR 0.13, CI 0.05-0.3), delay to arrival of the resuscitation team exceeding 2 min (median) (OR 0.4, CI 0.15-0.9) and the presence of documented clinical abnormal observations prior to the arrest (OR 0.3, CI 0.09-0.95).</AbstractText>Patients with documented clinically abnormal observations before IHCA have a worse outcome than those without, despite prompt resuscitation. Efforts should be made to identify these patients in time, thereby possibly avoiding the arrest. This can also be used when assessing the prognosis in IHCA.</AbstractText> |
9,517 | A moderate dose of propofol and rapidly induced mild hypothermia with extracorporeal lung and heart assist (ECLHA) improve the neurological outcome after prolonged cardiac arrest in dogs. | Propofol has been shown to protect against neuronal damage induced by brain ischaemia in small animal models. We reported previously that mild hypothermia (33 degrees C) in combination with extracorporeal lung and heart assist (ECLHA) improved the neurological outcome in dogs with cardiac arrest (CA) of 15 min induced during normothermia. In the present study, we investigated the neuroprotective effect of propofol infusion under mild hypothermia with ECLHA in this model.</AbstractText>Twenty-one female dogs (15 mongrel dogs and 6 beagles) were divided into three groups: Midazolam 0.1 mg/(kg h) infusion group (M, n=7), Propofol 2 mg/(kg h) infusion group (P2, n=7), Propofol 4 mg/(kg h) infusion group (P4, n=7). Normothermic ventricular fibrillation (VF) was induced in all dogs for 15 min, followed by brief ECLHA and 168 h of intensive care. The drug infusion was initiated at a constant rate after the restoration of spontaneous circulation (ROSC) to 24 h. Mild hypothermia (33 degrees C) was maintained for 20 h. Neurological deficit scores (NDS: 0%=normal, 100%=brain death) were evaluated for neurological function from 33 to 168 h.</AbstractText>One dog in the M group died, and the remaining dogs survived for 168 h. The P4 group showed better neurological recovery compared with the M group (48 h, 21+/-16% versus 32+/-15%; 72 h, 7+/-6% versus 25+/-11%; 96 h, 6+/-6% versus 21+/-6%; 120 h, 5+/-5% versus 20+/-6%; 144 h, 4+/-4% versus 20+/-6%; 168 h, 4+/-4% versus 20+/-6%, p<0.05). One dog in the P2 and three dogs in the P4 group achieved full neurological recovery (NDS: 0%). The number of intact pyramidal cells in the hippocampal CA1 was greater in the propofol groups than midazolam group (p<0.05).</AbstractText>The combination of propofol infusion at a rate of 4 mg/(kg h), 24h and rapidly induced mild hypothermia (33 degrees C) with ECLHA might provide a successful means of cerebral resuscitation from CA.</AbstractText> |
9,518 | Inter-rater reliability for witnessed collapse and presence of bystander CPR. | Witnessed collapse and bystander CPR are the variables most frequently associated with good outcome from out-of-hospital cardiac arrest (OOHCA). The reliability of abstracting witnessed collapse and bystander CPR from prehospital Emergency Medical Services (EMS) patient care records (PCRs) is not known. We sought to determine the inter-rater reliability for different methods of ascertaining and defining witnessed collapse and performance of bystander CPR.</AbstractText>A sample of 100 PCRs for patients with OOHCA was selected at random from a pool of 325 PCRs between May 2003 and January 2005. Paramedics used a drop down menu to indicate witnessed collapse and bystander CPR, and completed a narrative description of the event. An on-scene EMS physician also completed a data sheet. The PCR was examined by two separate evaluators to determine the presence of witnessed collapse and bystander CPR. A consensus was reached by three other reviewers using all available data sources. Inter-rater agreement was quantified using the unweighted kappa statistic.</AbstractText>For witnessed collapse, there is substantial agreement between the following: individual evaluators (kappa=0.76, S.D.=0.07), individual evaluators and consensus group (kappa=0.61, S.D.=0.07 and 0.66, S.D.=0.07), and physician and consensus group (kappa=0.68, S.D.=0.08). Agreement between individual evaluators and the physician was fair to moderate (kappa=0.38, S.D.=0.07 and 0.44, S.D.=0.07). Agreement between individual evaluators, physician, consensus group and the PCR drop down menu was fair to moderate (kappa range 0.33, S.D.=0.09 to 0.54, S.D.=0.09). For bystander CPR, there is substantial agreement between the individual evaluators and the consensus group (kappa=0.64, S.D.=0.07 and 0.63, S.D.=0.06) and between the physician and the consensus group (kappa=0.61, S.D.=0.08). Agreement between the two individual evaluators is moderate (kappa=0.59, S.D.=0.07). Agreement between the physician and individual evaluators is fair (kappa=0.36, S.D.=0.07 and 0.38, S.D.=0.07). The PCR drop down menu had moderate to substantial agreement with the individual evaluators, physician, and consensus group (kappa range 0.50, S.D.=0.09 to 0.75, S.D.=0.09).</AbstractText>Determination of witnessed collapse and bystander CPR during OOHCA may be less reliable than previously thought, and differences between methods of rating could influence study results.</AbstractText> |
9,519 | [Automatic external defibrillator (AED) and public access defibrillation (PAD)]. | Sudden death is a major public hazard and is usually caused by ventricular fibrillation (VF). Although in the majority of cases witnesses are to be found, resuscitation efforts are begun only in a minority of victims. The only treatment for VF is electrical shock and the time from collapse to resuscitation and defibrillation determine prognosis. Automated external defibrillator (AED) is a new device capable of effectively identifying and treating VF. It is unique in the sense that it can be operated by a non-medical operator following short training. Recent evidence of the survival benefit of AED utility is emerging. During the coming years, AEDs will be introduced to a growing number of hospitals and public places. This review summarizes the rationale for use, advantages, and disadvantages as well as the current status of AEDs and recommendations for placement of AEDs in Israel. |
9,520 | [Patients with recurrent malignant ventricular arrhythmias--therapeutic challenge]. | Patients with malignant refractory ventricular arrhythmias present a unique therapeutic challenge. In recent years, this challenge has become even more complex due to the wide spread use of implantable cardiac defibrillators. If, in the past, a majority of the patients succumbed due to these arrhythmias, today, due to the defibrillators, they survive and then need further treatment. The defibrillators treat the arrhythmias when they occur but in most cases do not prevent their initiation. In many cases we need to resort to other modalities. We present three patients who exemplify various options of dealing with this complex issue. |
9,521 | [Intravenous flecainide administration for conversion of paroxysmal atrial fibrillation in the emergency room]. | Since the removal of intravenous propafenone from the Israeli market, flecainide is the only intravenous antiarrhythmic class 1C drug available nowadays in Israel.</AbstractText>The study aimed to report our experience of intravenous flecainide administration in the treatment of paroxysmal atrial fibrillation (PAF) in the Emergency Room (ER).</AbstractText>Patients with AF lasting > 1 hour and <48 hour duration were considered possible candidates for entry into the study. Exclusion criteria were clinical signs of congestive heart failure, acute coronary syndrome, electrolyte imbalances, significant hepatic and renal disease, and any previously documented conduction disturbance. Flecainide was administered as a bolus dose of 2mg/kg in 10 minutes (maximum 150 mg). The patients with a ventricular response > 130 beats/min received intravenous verapamil or metoprolol in order to reduce the ventricular rate. Efficacy was defined as conversion to sinus rhythm (SR) within 120 minutes of starting medication.</AbstractText>Twenty three consecutive patients were enrolled in the study. Their mean age was 60 +/- 19 years; the mean ventricular response at admission was 128 +/- 26 beats/min. SR was achieved in 10 patients (43%) after the intravenous bolus of flecainide (10 minutes) and in 17 patients (74%) 120 minutes after the beginning of the therapy.</AbstractText>Hypotension (systolic blood pressure < 90 mmHg) was reported in 1 patient and QRS enlargement was seen in 1 patient.</AbstractText>Intravenous flecainide has effective and rapid action in the conversion of PAF and its administration is safe in the treatment of this arrhythmia in the ER.</AbstractText> |
9,522 | [Coronary artery surgery in women]. | Cardiovascular diseases are the leading cause of morbidity and mortality for women in developed countries. Numerous studies have shown that women have higher morbidity and mortality rates than men following coronary artery bypass graft surgery (CABG). Having this evidence as our starting point, we compared the outcomes of CABG procedures in women and men. The analysis included patient preoperative risk factors (age, left ventricular ejection fraction, diabetes mellitus, arterial hypertension, hypercholesterolemia, myocardial infarction and cerebrovascular insult), number of grafts and perioperative complications (reopening for bleeding, perioperative myocardial infarction, sternal wound infections--both superficial and deep, atrial and ventricular fibrillation, cardiac decompensation), and mortality. Women had more risk factors and comorbidities than man, including arterial hypertension and hypercholesterolemia, but less severe atherosclerosis and higher left ventricular ejection fraction. Off-pump myocardial revascularization was done in 48% of women and in 42% of men. There was no statistically significant difference in perioperative complications between women and men. Comparison of the mean values showed the perioperative mortality to be higher in women than in men (3.4% vs. 2.9%), but the difference was not statistically significant (p = 0.724). |
9,523 | [Methods and pharmacology in cardiopulmonary resuscitation. What's new?]. | Initiation of effective cardiopulmonary resuscitation (CPR) at the earliest possible time is the most important determinant of prognosis for patients with prehospital cardiac arrest. Basic life support CPR, defibrillation by emergency medical systems or first responders as well as vasopressor drugs or antiarrhythmics are essential.</AbstractText>Today, cardiocompression seems to be superior to ventilation. Defibrillation is the most effective treatment for ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). The effectiveness of defibrillation diminishes rapidly over time. The use of automated external defibrillators (AED) by first responders is very promising with excellent results caused by a short "call-to-arrival" time. Epinephrine and vasopressin are pressor drugs used in the treatment of cardiac arrest with similar success rates. Among antiarrhythmic drugs, lidocaine should no longer be used in patients with cardiac arrest, whereas amiodarone has high efficacy rates in VF or pulseless VT.</AbstractText>Technique and methods of resuscitation are ranging from CPR to additional drugs. Fast and consequent work is essential. Among the "chain of survival" there is an increased value of first responders.</AbstractText> |
9,524 | Cardiovascular outcomes with atrial-based pacing compared with ventricular pacing: meta-analysis of randomized trials, using individual patient data. | Several randomized trials have compared atrial-based (dual-chamber or atrial) pacing with ventricular pacing in patients with bradycardia. No trial has shown a mortality reduction, and only 1 small trial suggested a reduction in stroke. The goal of this review was to determine whether atrial-based pacing prevents major cardiovascular events.</AbstractText>A systematic review was performed of publications since 1980. For inclusion, trials had to compare an atrial-based with a ventricular-based pacing mode; use a randomized, controlled, parallel design; and have data on mortality, stroke, heart failure, or atrial fibrillation. Individual patient data were obtained from 5 of the 8 identified studies, representing 95% of patients in the 8 trials, and a total of 35 000 patient-years of follow-up. There was no significant heterogeneity among the results of the individual trials. There was no significant reduction in mortality (hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.87 to 1.03; P=0.19) or heart failure (HR, 0.89; 95% CI, 0.77 to 1.03; P=0.15) with atrial-based pacing. There was a significant reduction in atrial fibrillation (HR, 0.80; 95% CI, 0.72 to 0.89; P=0.00003) and a reduction in stroke that was of borderline significance (HR, 0.81; 95% CI, 0.67 to 0.99; P=0.035). There was no convincing evidence that any patient subgroup received special benefit from atrial-based pacing.</AbstractText>Compared with ventricular pacing, the use of atrial-based pacing does not improve survival or reduce heart failure or cardiovascular death. However, atrial-based pacing reduces the incidence of atrial fibrillation and may modestly reduce stroke.</AbstractText> |
9,525 | Bradycardia-dependent ECG changes in Brugada syndrome. | In patients with Brugada syndrome (BS), ventricular fibrillation (VF) occurs mainly during sleep; therefore, not only vagal activity but also bradycardia dependent changes in ECG may relate to the nighttime occurrence of VF. The present study aimed to examine the difference in bradycardia-dependent changes in the ECG of symptomatic and asymptomatic BS patients.</AbstractText>Twenty-one patients with BS were categorized into symptomatic (n = 9) and asymptomatic (n = 12) groups. During the electrophysiologic study, the ECG changes were evaluated at RR intervals of 400, 600, 750, 1,000 and 1,100 ms during extrastimulation from the right atrium. The ST levels in V2, and the QT interval in both V2 and V5 were measured. Along with an increase in the RR interval from 400 to 1,100 ms, the ST levels in V2 increased in both groups; the increase did not differ between the 2 groups. In both leads V2 and V5, the prolongation of the QT interval along with an increase in the RR interval from 400 to 1,100 ms was significantly smaller and the QT intervals at an RR interval of 1,100 ms were significantly shorter in the symptomatic than in the asymptomatic group.</AbstractText>In patients with BS, the ST elevation was augmented during bradycardia to a similar extent in both symptomatic and asymptomatic patients. However, a inhibited prolongation of the QT interval during bradycardia was characteristic of symptomatic patients. These unique repolarization dynamics could relate to the nighttime occurrence of VF during bradycardia in patients with BS.</AbstractText> |
9,526 | Location of out-of-hospital cardiac arrests in Takatsuki City: where should automated external defibrillator be placed. | Public access defibrillation has been introduced to improve the outcome of patients experiencing out-of-hospital cardiac arrest (OHCA). The aim of this study was to examine the best location for automated external defibrillators (AED).</AbstractText>All patients who were resuscitated after OHCA by emergency medical technicians in Takatsuki City over 6 years were enrolled. The annual incidence of OHCA and the number of 1-year survivors with good neurological outcome in each of 21 sub-location categories were investigated, as well as the ratio of ventricular fibrillation (VF) as the initial rhythm to the total OHCA in each of 5 location categories. In total, there were 1,112 patients with OHCA, 62 (5.6%) with VF and 14 (1.3%) with good neurological outcome. The annual incidence of cardiac arrest (CA) per site was the highest in railway stations (0.3000), followed by hospitals (0.1802), homes for the aged (0.1115), playgrounds (0.0769) and golf courses (0.0667). However, none of the patients experiencing CA at railway stations, homes for the aged and golf courses had a good neurological outcome. The ratio of VF to total CA was the highest in the workplace (35.3%).</AbstractText>The 6 locations, including workplace, are recommended as appropriate locations for AED.</AbstractText> |
9,527 | Natriuretic peptides in patients with atrial fibrillation and advanced chronic heart failure: determinants and prognostic value of (NT-)ANP and (NT-pro)BNP. | To study the determinants of natriuretic peptides in advanced chronic heart failure (CHF) patients with and without atrial fibrillation (AF) and to evaluate the prognostic value of natriuretic peptides in AF compared with sinus rhythm patients with advanced CHF.</AbstractText>The study group comprised 354 advanced CHF patients [all New York Heart Association (NYHA) III/IV], including 76 AF patients. AF patients were older (70+/-7 vs. 67+/-8; P=0.01), and non-ischaemic CHF was more common (42 vs. 19%; P=0.002) than in sinus rhythm patients, but left-ventricular ejection fraction was comparable (0.23+/-0.08 vs. 0.24+/-0.07; P=ns). At baseline, (NT-)ANP and NT-proBNP levels were significantly higher in AF patients, compared with those in sinus rhythm. By multivariate regression analysis, AF was identified as independent determinant of (NT-)ANP, but not of (NT-pro)BNP levels. After a mean follow-up of 3.2+/-0.9 (range 0.4-5.4) years, cardiovascular mortality was comparable (55 vs. 47%; P=ns). In both groups, AF and sinus rhythm, NT-proBNP [AF: adjusted HR 5.8 (1.3-25.4), P=0.02; sinus rhythm: adjusted HR 3.1 (1.7-5.7), P<0.001] was an independent risk indicator of cardiovascular mortality.</AbstractText>In advanced CHF patients, AF affects (NT-)ANP levels, but not (NT-pro)BNP levels. NT-proBNP is an independent determinant of prognosis in advanced CHF, irrespective of the rhythm, AF, or sinus rhythm.</AbstractText> |
9,528 | Incidence and types of arrhythmias after mediastinal manipulation during transhiatal esophagectomy. | Transhiatal esophagectomy (THE) is a common operative procedure for carcinoma esophagus. Complications of this procedure include arrhythmias and hypotension during blunt dissection of the esophagus from posterior mediastinum. In the literature, exact incidence and type of arrhythmias have not been reported. We employed Holter monitoring during mediastinal manipulation in patients undergoing THE, for this purpose.</AbstractText>This prospective study was carried out in 20 consecutive American Society of Anesthesiologists grade I-II patients undergoing THE. Anesthetic technique included induction with thiopentone and maintenance with morphine, vecuronium, and isoflurane. In addition to routine parameters, Holter monitoring was undertaken to record the exact incidence and types of arrhythmias. "Premanipulation" or control period included duration of 30 minutes preceding mediastinal manipulation, while "during manipulation" or study period included the duration of mediastinal manipulation. The incidence of arrhythmias was studied for 48 hours in the postoperative period. The Fisher exact test was applied to analyze incidence of arrhythmias and hypotension.</AbstractText>Out of 20 patients, only 2 had arrhythmias in the premanipulation period, while 13 had arrhythmias during the manipulation period (p < 0.01). During the manipulation period, arrhythmias included supraventricular ectopics and ventricular ectopics in 2 patients each and a combination of both in 9 patients. Arrhythmias were transient and had no correlation with either duration or degree of hypotension in all the patients. However, there was a linear relationship between hypotension and duration of mediastinal manipulation. Two patients (10%) had atrial arrhythmias in the postoperative period.</AbstractText>In transhiatal esophagectomy, there is a significant incidence of both arrhythmias and hypotension during mediastinal manipulation. The incidence of arrhythmias can be minimized by limiting the duration of the manipulation. The incidence of postoperative arrhythmias was not significant.</AbstractText> |
9,529 | Transapical aortic valve implantation: an animal feasibility study. | Percutaneous aortic valve implantation has recently been performed in nonsurgical patients with severe aortic stenosis. Retrograde valve delivery has been problematic because of the size of the delivery system and concomitant peripheral vascular disease. We investigated a minimally invasive approach through the left ventricular apex for antegrade placement of a device-deliverable valve.</AbstractText>Transapical aortic valve implantation was performed using a 23-mm equine valve mounted on a stainless steel stent in 24 swine (weight range, 35 to 45 kg). A limited or full sternotomy approach was used to access the apex of the heart. The crimped valve was introduced through a sheath in the left ventricular apex. Fluoroscopy and echocardiography were used for guidance. Deployments were performed on the beating heart either with ventricular unloading using femoral extracorporeal circulation or rapid ventricular pacing.</AbstractText>All valves were successfully delivered at the selected target site with acceptable visualization of the noncalcified aortic annulus. Valve migration occurred during eight deployments (two distal and six retrograde) secondary to persistent cardiac output, unfavorable annular anatomy, and dislodgement by the delivery catheter. Exact positioning of the nonmigrated valves at the aortic annulus was examined by necropsy of all animals at the end of the procedures. Paravalvular leak was noted in 14 of 18 (77.8%) valves remaining in situ.</AbstractText>The transapical approach was used for the successful antegrade placement of a stented valve, obviating the technical problems associated with a large delivery system transiting the peripheral vascular system. Stent design contributing to paravalvular leak remains problematic.</AbstractText> |
9,530 | Paroxysmal atrial fibrillation precipitated by amiodarone-induced thyrotoxicosis five months after cessation of therapy. | Amiodarone is currently indicated for the treatment of life-threatening ventricular dysrhythmias. It is also used for the treatment of supraventricular dysrhythmias and as maintenance therapy after successful cardioversion of atrial flutter or atrial fibrillation. Adverse effects related to its expanded use are increasingly common. We describe a case of amiodarone-induced thyrotoxicosis occurring 5 months after cessation of therapy and discuss the pathophysiology and treatment of this disorder. |
9,531 | Elimination of cardiac arrhythmias using oral taurine with l-arginine with case histories: Hypothesis for nitric oxide stabilization of the sinus node. | We searched for nutrient deficiencies that could cause cardiac arrhythmias [premature atrial contractions (PACs), premature ventricular contractions (PVCs), atrial fibrillation, and related sinus pauses], and found literature support for deficiencies of taurine and l-arginine. Case histories of people with very frequent arrhythmias are presented showing 10-20g taurine per day reduced PACs by 50% and prevented all PVCs but did not prevent pauses. Adding 4-6g of l-arginine immediately terminated essentially all remaining pauses and PACs, maintaining normal cardiac rhythm with continued treatment. Effects of taurine useful in preventing arrhythmias include regulating potassium, calcium and sodium levels in the blood and tissues, regulating excitability of the myocardium, and protecting against free radicals damage. Taurine restored energy and endurance in one of the cases from a debilitated status to normal. Arrhythmias may also respond to taurine because it dampens activity of the sympathetic nervous system and dampens epinephrine release. l-arginine may have anti-arrhythmic properties resulting from its role as a nitric oxide (NO) precursor and from its ability to restore sinus rhythm spontaneously. Endogenous production of taurine and l-arginine may decline in aging perturbing cardiac rhythm, and these "conditional" essential nutrients therefore become "essential" and require supplementation to prevent morbidity and mortality. l-arginine is hypothesized to prevent cardiac arrhythmias by NO stabilization of the sinus node. Cardiac arrhythmias having no known cause in otherwise healthy people are hypothesized to be symptoms of deficiencies of taurine and arginine. |
9,532 | [Pulmonary vein antrum isolation guided by 3-D mapping system in 100 patients with chronic atrial fibrillation]. | To investigate the efficacy and safety of circumferential pulmonary vein (PV) linear ablation (CPVA) guided by 3-D mapping system in patients with chronic atrial fibrillation (CAF).</AbstractText>From August 2004 to November 2005, 100 consecutive patients with CAF were admitted to undergo CPVA guided by CARTO system and EnSite NavX system, the main procedure end point is electrical isolation of PVs. Success was defined as atrial tachyarrhythmia free without any antiarrhythmia drugs for at least 3 months. Clinical and procedural variables were collected, ANOVA analysis was employed to identify the risk factors predicting recurrence, P < 0.05 was considered significant.</AbstractText>After a mean of 9.7 +/- 5.7 months follow up, 70% (70/100) of patients freed from AF. ANOVA analysis identified isthmus ablation and poor left ventricular ejection fraction as the independent factors predicting success. Complications including pericardial tamponade (3 cases, 3%), stroke (1 case, 1%), asymptomatic pulmonary vein stenosis (2 cases, 2%).</AbstractText>CPVA guided by 3-D mapping system can be performed in CAF patients with an acceptable efficacy, but safety need to be improved.</AbstractText> |
9,533 | Cardiac troponin I and ventricular arrhythmia in patients with chronic heart failure. | Both detectable serum cardiac troponin I (cTnI) and ventricular dysrhythmias are common in patients with chronic heart failure (CHF) and are paralleled with the severity of the CHF. However, the relationship between serum cTnI and ventricular arrhythmia severity in patients with CHF remains unknown; the mechanism of the ventricular arrhythmia in the CHF patients also remains unclear.</AbstractText>The study group included 218 patients with CHF who had cTnI assay drawn at the time of initial presentation. Patients with acute myocardial infarction or myocarditis were excluded from the analysis. The patients were divided into two groups: cTnI-positive with serum cTnI > 0.5 ng mL(-1) (n = 98) and cTnI-negative with serum cTnI < or = 0.5 ng mL(-1) (n = 120). The severity of ventricular dysrhythmias was assessed by 24-h Holter monitoring, using prospectively defined measures of ventricular arrhythmic burden.</AbstractText>Prevalence of risk factors for ventricular dysrhythmias was equal in both groups. All measures of ventricular ectopy were much higher in patients of the cTnI-positive groups. Mean hourly ventricular pairs (13.59 +/- 10.3 vs. 11.1 +/- 6.01, P = 0.027), mean hourly repetitive ventricular beats (26.01 +/- 13.67 vs. 22.01 +/- 13.56, P = 0.032), and the frequency of ventricular tachycardia episodes per 24 h (12.54 +/- 16.68 vs. 7.68 +/- 11.54, P = 0.012) were higher in patients with detectable cTnI levels. After inclusion of clinical variables and drug therapies in a multivariate analysis, the positive relationship between cTnI and the frequency of ventricular pairs (P = 0.03), repetitive ventricular beats (P = 0.037), and ventricular tachycardia (P = 0.03) remained independent. In multivariate logistic regression, the risk of developing ventricular tachycardia was higher in patients with detectable cTnI levels with an adjusted odds ratio (OR) of 2.31 (95% CI, 1.22-2.65, P = 0.003).</AbstractText>In patients with CHF, serum cTnI is closely related to increased occurrence of ventricular dysrhythmias and could identify a subgroup of patients with ventricular tachycardia. The minimal myocardial injury detected by serum cTnI might be the abnormal substrate for ventricular dysrhythmias.</AbstractText> |
9,534 | Cardiopulmonary resuscitation in a rat model of chronic myocardial ischemia. | Our group has developed a rat model of cardiac arrest and cardiopulmonary resuscitation (CPR). However, the current rat model uses healthy adult animals. In an effort to more closely reproduce the event of cardiac arrest and CPR in humans with chronic coronary disease, a rat model of coronary artery constriction was investigated during cardiac arrest and CPR. Left coronary artery constriction was induced surgically in anesthetized, mechanically ventilated Sprague-Dawley rats. Echocardiography was used to measure global cardiac performance before surgery and 4 wk postsurgery. Coronary constriction provoked significant decreases in ejection fraction, increases in left ventricular end-diastolic volume, and increases left ventricular end-systolic volume at 4 wk postintervention, just before induction of ventricular fibrillation (VF). After 6 min of untreated VF, CPR was initiated on three groups: 1) coronary artery constriction group, 2) sham-operated group, and 3) control group (without preceding surgery). Defibrillation was attempted after 6 min of CPR. All the animals were resuscitated. Postresuscitation myocardial function as measured by rate of left ventricular pressure increase at 40 mmHg and the rate of left ventricular pressure decline was more significantly impaired and left ventricular end-diastolic pressure was greater in the coronary artery constriction group compared with the sham-operated group and the control group. There were no differences in the total shock energy required for successful resuscitation and duration of survival among the groups. In summary, this rat model of chronic myocardial ischemia was associated with ventricular remodeling and left ventricular myocardial dysfunction 4 wk postintervention and subsequently with severe postresuscitation myocardial dysfunction. This model would suggest further clinically relevant investigation on cardiac arrest and CPR. |
9,535 | [Risk stratification in atrial and ventricular arrhythmias]. | Atrial fibrillation, the most frequent arrhythmia, has a growing incidence with increasing age and the most important complication of the disease is thromboembolic events that may be prevented by antivitamin K. They are the most efficient therapeutic class for the prevention of these events but they are associated with an increased haemorrhagic risk leading to a reduced prescription in general practice. Optimisation of the management should be based on an individual evaluation of the thromboembolic and haemorrhagic risks, taking into account age, the presence of an associated heart disease, hypertension, diabetes, history of cerebrovascular event, history of previous haemorrhagic event and the ability to achieve a stable target INR. The challenge in ventricular arrhythmias lies in identifying a high risk of sudden death, mainly related to ventricular fibrillation. In patients with structural heart disease, left ventricular dysfunction is the strongest predictor of sudden death. Non invasive markers such as non sustained ventricular tachycardia, late ventricular potentials, decreased heart rate variability and baroreflex sensitivity, and repolarization altemans are further elements to assess risk. However, most of these markers have a poor positive predictive value and a low specificity. In patients with normal hearts, genetic predisposition may in the future identify high risk patients. The electrophysiologic study with programmed ventricular stimulation remains a costly and invasive method and only has a strong positive predictive value in ischemic cardiomyopathy. More precise algorithms for risk stratification are thus needed that may help the strategy of therapy with prophylactic implantable cardioverter defibrillator in the future. |
9,536 | Cardiac arrhythmias in the intensive care unit. | Cardiac arrhythmias are a common problem encountered in the intensive care unit (ICU) and represent a major source of morbidity. Arrhythmias are most likely to occur in patients with structural heart disease. The inciting factor for an arrhythmia in a given patient may be an insult such as hypoxia, infection, cardiac ischemia, catecholamine excess (endogenous or exogenous), or an electrolyte abnormality. Management includes correction of these imbalances as well as medical therapy directed at the arrhythmia itself. The physiological impact of arrhythmias depends on ventricular response rate and duration, and the impact of a given arrhythmia in a given situation depends on the patient's cardiac physiology and function. Similarly, urgency and type of treatment are determined by the physiological impact of the arrhythmia as well as by underlying cardiac status. The purpose of this review is to provide an update regarding current concepts of diagnosis and acute management of arrhythmias in the ICU. A systematic approach to diagnosis and evaluation will be presented, followed by consideration of specific arrhythmias. |
9,537 | [Cardiac arrhythmias in women]. | The aim of this study was to review published data on gender differences in cardiac electrophysiology and in the presentation and clinical treatment of arrhythmias. The evidence from studies published to date show that women have a higher mean resting heart rate, a longer QT interval, a shorter QRS duration, and a lower QRS voltage than men. Women have a higher prevalence of sick sinus syndrome, inappropriate sinus tachycardia, atrioventricular nodal reentry tachycardia, idiopathic right ventricular tachycardia, and arrhythmic events in the long-QT syndrome. In contrast, men have a higher prevalence of atrioventricular block, carotid sinus syndrome, atrial fibrillation, supraventricular tachycardia due to accessory pathways, Wolff-Parkinson-White syndrome, reentrant ventricular tachycardia, ventricular fibrillation and sudden death, and the Brugada syndrome. With regard to implantable devices, it has been reported that defibrillators offer similar benefits in men and women. Moreover, there is no gender difference in the percentage who respond well to resynchronization therapy: survival is similar in the two sexes. However, it should be noted that few women have participated in studies of all types of therapy, including catheter ablation, resynchronization therapy, and the use of implantable defibrillators. |
9,538 | [The implantable cardioverter-defibrillator and hypertrophic cardiomyopathy. Experience at three centers]. | Although implantable cardioverter-defibrillators (ICDs) are recommended for high-risk patients with hypertrophic cardiomyopathy (HCM), there is no agreement on their general use. Moreover, little information is available on ICD use in this setting in Spain. Our aims were to describe the characteristics of HCM patients who received ICDs at three hospitals in Spain, and to study indications for device implantation and the results of follow-up in device users.</AbstractText>We evaluated risk factors for sudden death in HCM patients with ICDs, including family history of sudden death, recurrent syncope, maximum wall thickness > or =30 mm, left ventricular outflow pressure gradient >30 mmHg, abnormal blood pressure response to exercise, and nonsustained ventricular tachycardia. During regular follow-up, appropriate and inappropriate administration of ICD therapy was recorded.</AbstractText>Of 726 HCM patients, 45 (6.2%) had an ICD (mean age 43 [20] years). The proportion of patients with ICDs at the three centers studied was highly variable despite patients' clinical characteristics being similar. The indication for implantation was primary prevention in 27 patients and secondary prevention in 18. During follow-up (median 32 months), ICD therapy was administered appropriately in 10 (22.0%) patients (in nine, as secondary prevention and, in one, as primary prevention). The annual appropriate ICD therapy rate was 11.1% for secondary prevention and 1.6% for primary prevention. Two patients received an ICD to treat ventricular fibrillation and eight, to treat sustained ventricular tachycardia. The only significant predictor of appropriate ICD therapy was a history of sustained ventricular tachycardia or ventricular fibrillation (hazard ratio =13.3, P=.014).</AbstractText>The percentage of HCM patients undergoing ICD implantation at Spanish hospitals was highly variable, possibly due to different selection criteria. When used as secondary prevention, ICD therapy was administered appropriately in a high proportion of cases (50% in 3 years).</AbstractText> |
9,539 | High titer of anticardiolipin antibody is associated with first-ever ischemic stroke in Taiwan. | The association between anticardiolipin antibody (aCL) and ischemic stroke is controversial, and there are few case-control studies of Asian populations. The aim of this study, therefore, was to determine whether aCL is an independent risk factor for ischemic stroke in Taiwanese patients over the age of 40 years.</AbstractText>Both the IgG and IgM isotypes of aCL were measured in 273 patients (> 40 years of age) hospitalized for first-ever ischemic stroke and in 181 non-stroke controls. Results were defined as: negative (< 10 IgG phospholipid units [GPL] or < 7.5 IgM phospholipid units [MPL]); low positive (10-20 GPL or 7.5-15 MPL); or, high positive (> 20 GPL or > 15 MPL). Odds ratios (OR) were estimated by logistic regression with adjustment for potential confounders.</AbstractText>A high positive IgG aCL was present in 4.4% of the stroke patients and 1.2% of the controls. Age- and sex-adjusted analysis showed a borderline association between a high positive level for aCL IgG titer and stroke, with an OR of 4.01 (95% CI 0.87-18.37; p = 0.0739). Final analysis, with adjustments for age, sex, hypertension, diabetes, tobacco smoking, atrial fibrillation, left ventricular hypertrophy and hyperlipidemia, revealed an OR of 5.25 (95% CI 1.06-25.89; p = 0.0419).</AbstractText>The results of this study suggest that elevated titer of aCL IgG (> 20 GPL) is associated with first-ever ischemic stroke in Taiwanese patients aged over 40 years. High positive aCL titer is related to ischemic stroke after adjustment for conventional cerebrovascular risk factors, indicating that it is probably an independent risk factor for ischemic stroke.</AbstractText>Copyright 2006 S. Karger AG, Basel.</CopyrightInformation> |
9,540 | Potential benefit of transesophageal defibrillation: an experimental evaluation. | Because of the proximity of the esophagus to the heart, transesophageal defibrillation might increase defibrillation success. We assessed the defibrillation threshold (DFT) of transesophageal defibrillation compared with standard transthoracic defibrillation.</AbstractText>Defibrillation success and DFTs were determined in 22 female pigs with high (68+/-4 kg, n=12) or low body weight (39+/-1 kg, n=10). After induction of ventricular fibrillation, biphasic shocks were delivered between two cutaneous patch electrodes (sternal and apical position) or between an esophageal and two cutaneous patch electrodes in a sternal and apical position. The esophageal electrode was integrated into a latex sheath covering a standard transesophageal echocardiography probe.</AbstractText>In 5 of 12 pigs with high body weight, external defibrillation failed despite 3 consecutive 200-J shocks, whereas subsequent transesophageal defibrillation was successful with the first shock. In the remaining 7 pigs, a more than 50% reduction in DFT was obtained with transesophageal defibrillation compared with standard biphasic external defibrillation (67+/-27 vs 164+/-23 J, P<.001). Pigs with lower body weight were successfully defibrillated by both transthoracic and transesophageal shocks. The DFT in pigs with low body weight was significantly lower using transesophageal defibrillation compared with transthoracic shocks (65+/-15 vs 99+/-38 J, P<.05).</AbstractText>In this animal model, nonresponders to standard external defibrillation could successfully be defibrillated via an esophageal-cutaneous electrode configuration. Overall, an almost 50% DFT reduction was achieved by transesophageal defibrillation. Transesophageal defibrillation may provide an additional tool for terminating VF, which is refractory to external defibrillation, eg, in patients with very high body weight.</AbstractText> |
9,541 | Suicide due to oral ingestion of lidocaine: a case report and review of the literature. | The Authors describe a rare case of suicide in a 31-year-old woman, due to oral ingestion of lidocaine; the histological and toxicological findings are discussed to provide useful information to the present experience with this particular modality of death. Histological examination revealed generalized stasis. In the myocardium we observed segmentation of the myocardial cells and/or widening of intercalated discs and associated group of hypercontracted myocardial cells with "square" nuclei in line with hyperdistended ones. Non-eosinophilic bands of hypercontracted sarcomeres alternating with stretched, often apparently separated sarcomeres, small foci of paradiscal contraction band necrosis, and perivascular fibrosis were observed too. Lidocaine was detected in the subject's urine through immunoenzymatic screening. Toxicological analysis by solid-liquid extraction and gas chromatography-mass spectrometry (GC-MS) analysis, was carried out to identify and quantify the individual substances present in the biological fluids and organs. Lidocaine concentrations were as follows: blood 31 microg/mL, gastric content 2.5 g, liver 10 microg/g, kidney 12 microg/g, brain 9 microg/g, spleen 24 microg/g, lung 84 microg/g, heart 9 microg/g, urine 9 microg/mL, and bile 6 microg/mL. No other drugs or alcohol were detected. When blood lidocaine reaches toxic levels, serious toxic symptoms associated with the central nervous system and cardiac system are noted. The overdose of lidocaine produces death from ventricular fibrillation or cardiac arrest. In this case, according to macroscopic and microscopic findings, the cause of death was most likely cardiac and possibly related to ventricular fibrillation. |
9,542 | [Management of atrial flutter in 2006]. | Typical or common atrial flutter is a frequent cardiac arrhythmia related to a macroreentrant circuit located entirely within the right atrium. Risks associated with this supraventricular arrhythmia include 1 to 1 conduction with extremely rapid ventricular rates, tachycardia-mediated cardiomyopathy and thromboembolic events. Treatment of choice of atrial flutter is radiofrequency catheter ablation of the cavo-tricuspid isthmus, and this form of treatment may be considered either during the first episode or at the time of the first recurrence of atrial flutter. Anticoagulant therapy is the rule in the presence of atrial flutter because this arrhythmia favors thromboembolic complications and because atrial flutter is frequently associated with atrial fibrillation. |
9,543 | Upsurge in T-wave alternans and nonalternating repolarization instability precedes spontaneous initiation of ventricular tachyarrhythmias in humans. | Analysis of repolarization instability, manifested by T-wave alternans (TWA), has proved useful for arrhythmia risk assessment. However, temporal relations between TWA and the spontaneous initiation of ventricular tachyarrhythmias (VTA) in humans are unknown. We examined continuous dynamics of repolarization in Holter electrocardiograms with spontaneous sustained (>30 seconds) VTA.</AbstractText>Ambulatory electrocardiograms from 42 patients (79% with ischemic heart disease; left ventricular ejection fraction, 37+/-15%) were digitized, and the lead with the highest magnitude of the T wave was selected for analysis. TWA was examined by the modified moving average and intrabeat average analyses. To examine non-TWA (longer-period) oscillations in the repolarization segment, spectral energy of oscillations of consecutive T-wave amplitudes was calculated with the use of the short-time Fourier transform. Heart rate variability was assessed with the Fourier transform as well. TWA increased before the onset of VTA and reached a peak value of 23.6+/-11.7 microV 10 minutes before the event (P=0.0007). Spectral power of the oscillations of consecutive T-wave amplitudes increased nonuniformly, with the greatest increase in the respiratory range (2.6 microV2; P=0.005). In the TWA range, the change was smaller but highly pronounced relative to the 60- to 120-minute level (65%; P=0.003). The low-frequency and high-frequency heart rate variability power declined before the arrhythmia (P=0.04 and P=0.06, respectively).</AbstractText>The magnitude of repolarization instability, manifested by TWA and beat-to-beat oscillations of T-wave amplitudes at other frequencies, increased before the onset of VTA. Tracking of these dynamics can facilitate timely detection of high-risk periods and may be useful for initiation of preventive treatments.</AbstractText> |
9,544 | Atrial secretion of B-type natriuretic peptide. | In the normal heart, the endocrine capacity resides in the atria. Atrial myocytes express and secrete natriuretic hormones that regulate fluid homeostasis and blood pressure. But in ventricular disease, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) gene expression is also activated in ventricular myocytes. Plasma concentrations of natriuretic peptides and their biosynthetic precursors are accordingly increased in patients with marked ventricular dysfunction. In contrast, atrial peptide secretion in ventricular disease has received less attention, and our present understanding of the endocrine atria during ventricular dysfunction is still scarce. Although ventricular disease and increased circulating concentrations are associated, it does not entail that the ventricle is the sole or even the main source in all types of heart disease. Clearly, the endocrine atria are also active in heart failure. Plasma measurement of cardiac natriuretic peptides and their molecular precursors can perhaps help us to discriminate when, where and how. |
9,545 | Reduced effectiveness of hypothermia in patients lacking the wave V in auditory brainstem responses immediately following resuscitation from cardiac arrest. | Therapeutic hypothermia appears to improve the outcome of pre-hospital cardio-pulmonary arrest (CPA) in patients with an initial cardiac rhythm of ventricular fibrillation or nonperfusing ventricular tachycardia (VF/VT). Notwithstanding, the outcome of this procedure is certainly difficult to predict based solely on the initial rhythm. The aim of the present study was to predict the outcome using auditory brainstem responses (ABRs) in CPA patients treated with therapeutic hypothermia.</AbstractText>A prospective observational study in the intensive care unit of a university hospital.</AbstractText>The study included 26 patients resuscitated from out-of-hospital CPA.</AbstractText>Basic and advanced cardiac life support, intensive care and post-resuscitative hypothermia.</AbstractText>ABRs were recorded immediately after the return of spontaneous circulation (ROSC). An ABR wave V was recorded in 16 patients. Among 8 patients with a favourable outcome, the initial rhythms were VF/VT in 6 patients and other rhythms in 2. All 10 patients without a detectable ABR wave V had an unfavourable outcome. The VF/VT as the initial arrest rhythm and the presence of wave V were significantly (p = 0.0095) correlated with a favourable outcome. The presence of wave V had a 100% sensitivity to a favourable outcome.</AbstractText>The absence of the ABR wave V in the early phase after ROSC wave indicated a reduced effect of therapeutic hypothermia, even in cases that underwent hypothermia promptly after out-of-hospital CPA. Measurement of ABRs appears to be useful as a predictor of effectiveness and as a criterion for determining the indication for therapeutic hypothermia.</AbstractText> |
9,546 | Determinants of thoracic electrical impedance in external electrical cardioversion of atrial fibrillation. | The success of external cardioversion (ECV) of atrial fibrillation depends on generating sufficient transmyocardial current for defibrillation with minimal myocardial injury. Thoracic electrical impedance plays an important role in the relation between the delivered energy and transmyocardial current. This study assessed the determinants of thoracic electrical impedance in ECV of atrial fibrillation. ECV of atrial fibrillation was performed in 80 consecutive patients (mean age 73 +/- 9 years; men 69%; body mass index 26.0 +/- 3.6 kg/m(2)) within 12 months, using biphasic shocks (Multipulse Biowave) delivered through adhesive pads in an anteroposterior position. Thoracic electrical impedance was measured using the first shock. The mean thoracic electrical impedance was 57.7 +/- 12.3 Omega (energy 71 +/- 43 J, current intensity 33 +/- 12 A). Sinus rhythm was immediately restored in 75 patients (94%). Thoracic electrical impedance was greater (60.9 +/- 11.8 vs 51.7 +/- 11.0 Omega, p = 0.001) in patients requiring >1 shock (65%). At multivariate linear regression analysis (R = 0.761, p <0.001), female gender (+9.7 +/- 2.0 Omega, p <0.001), body mass index (+1.5 +/- 0.3 for a 1 kg/m(2) increase, p <0.001), hemoglobin concentration (+1.9 +/- 0.6 for a 1 g/dl increase, p = 0.004), and the presence of chronic heart failure (-5.3 +/- 2.0 Omega, p = 0.009) were independent predictors of thoracic electrical impedance. In conclusion, to increase ECV efficacy and minimize complications, the delivered energy should be adjusted in accordance with the clinical variables that independently affect thoracic electrical impedance and, hence, transmyocardial current. |
9,547 | A coroner's request for closure: the value of the stored electrogram. | Pacemaker diagnostics can be useful to troubleshoot both during life and after death. A 58-year old man with a single chamber ventricular pacemaker and a previous His bundle ablation died suddenly. Interrogation of his pacemaker revealed the cause of death not as pacemaker malfunction, but a fatal ventricular arrhythmia. |
9,548 | Discordant regulation of CRP and NT-proBNP plasma levels after electrical cardioversion of persistent atrial fibrillation. | B-type natriuretic peptide (BNP) and C-reactive protein (CRP) have been suggested to be prognostically relevant markers in patients with cardiovascular disease. Additionally, BNP and CRP plasma levels seem to be independently elevated in patients with atrial fibrillation (AF). However, there are only sparse data about the significance and temporal course of these plasma markers after restoration of sinus rhythm (SR).</AbstractText>We performed a prospective study in consecutive patients with symptomatic atrial fibrillation. NT-proBNP and CRP plasma levels were measured before and one month after electrical cardioversion (CV). Patients with infections, an acute coronary syndrome, or surgery 4 weeks prior to CV, were excluded.</AbstractText>Twenty-five patients (men 84%, age 66 +/- 8 years, duration of AF 90 +/- 75 days, left ventricular ejection fraction 0.57 +/- 0.11) were analyzed. At follow-up (33 +/- 6 days after CV) 14 patients (56%) were in SR and 11 patients (44%) in AF. In patients with SR there was a significant reduction of NT-proBNP levels (baseline 1647 +/- 1272 pg/mL, follow-up 772 +/- 866 pg/mL, P < 0.05), even in a subgroup of patients (n = 10) with normal left ventricular ejection fraction (1262 +/- 538 vs 413 +/- 344 pg/mL, P < 0.001). CRP levels in patients with SR were similar at baseline and at follow-up (3.5 +/- 3.6 vs 3.2 +/- 2.5 mg/L, P = 0.8).</AbstractText>We conclude that even in patients with normal left ventricular ejection fraction restoration of sinus rhythm leads to a significant reduction of NT-proBNP plasma levels. In contrast, CRP plasma levels seem not to be influenced during the first 4 weeks after electrical cardioversion.</AbstractText> |
9,549 | Outcomes and predictors of success of a radiofrequency- or cryothermy-simplified left-sided maze procedure in patients undergoing mitral valve surgery. | Restoration of sinus rhythm with a maze procedure after concomitant mitral valve (MV) surgery has been shown to reduce the rate of stroke and improve cardiac function and quality of life compared to MV surgery alone. Unlike the classical Cox-Maze III operation, a simplified left-sided maze procedure can be performed without any significant increase in operative complexity.</AbstractText>Outcomes were compared retrospectively between radiofrequency (RF) and cryothermy as an energy source and analyzed predictors of outcome in 73 consecutive patients undergoing MV surgery with a concomitant simplified left-sided maze procedure. Clinical characteristics as well as rhythm and complication rate at follow up were assessed by review of medical records and patient and physician interview.</AbstractText>There were no complications associated directly with the maze procedure. At an average follow up of 342 days, 69% of patients were in normal sinus rhythm. Of the remainder, 30% had recurrent atrial fibrillation (AF) and 1% atrial flutter. In addition, 7% of patients required cardioversion and 14% required anti-arrhythmic therapy to maintain sinus rhythm. Patients with recurrent AF were more likely to have an enlarged right atrium or Carpentier Type IIIa mitral regurgitation on preoperative echocardiography, and more likely to have undergone concomitant aortic or tricuspid valve surgery. There was no difference in outcome between RF and cryothermy as an energy source in unadjusted or adjusted analyses.</AbstractText>The results of the study helped to establish RF- or cryothermy-simplified left-sided maze procedure as being efficacious and without associated complications in patients having MV surgery and a history of AF. Further investigations are warranted to better define the clinical predictors of recurrent AF to improve patient selection and potentially to modify current maze techniques.</AbstractText> |
9,550 | Cardiopulmonary exercise testing determination of functional capacity in mitral regurgitation: physiologic and outcome implications. | This study was designed to evaluate prevalence, determinants, and clinical outcome implications of reduced functional capacity (FC) in patients with organic mitral regurgitation (MR).</AbstractText>Evaluation of FC by exercise testing is rarely performed in MR because little is known about the clinical determinants and outcome implications of FC.</AbstractText>Cardiopulmonary exercise testing (CPET) was prospectively performed in 134 asymptomatic patients with organic MR to assess FC (peak oxygen consumption [VO2]) simultaneously to Doppler-echocardiographic quantitation of MR (effective regurgitant orifice [ERO]) and left ventricular (LV) systolic and diastolic function.</AbstractText>Peak VO2 was 26 +/- 6 ml/kg/min (96 +/- 16% of age-predicted), but varied widely (57% to 145% of predicted) and was markedly reduced (< or =84% of predicted) in 19% of patients. Although ERO of MR was univariately associated with reduced FC (26 vs. 9% with ERO > or =40 vs. <40 mm2), independent determinants of reduced FC were LV diastolic function (higher E/E' ratio, p = 0.006), atrial fibrillation (p = 0.01), and lower forward stroke volume (p = 0.03). Clinical events (death, heart failure, new atrial fibrillation) and clinical events or surgery were more frequent with than without reduced FC (3 years, 36 +/- 14% vs. 13 +/- 4%, p = 0.02; and 66 +/- 11% vs. 29 +/- 5%, p = 0.001, respectively), even adjusting (risk ratios 1.80 and 1.54 respectively, both p < or = 0.03) for age and ERO.</AbstractText>In asymptomatic organic MR, FC quantitatively assessed by CPET is unexpectedly markedly reduced in one out of every four to five patients. Reduced FC is independently determined by consequences rather than severity of MR and predicts increased subsequent clinical events. Therefore, CPET frequently reveals functional limitations not detected clinically and is an important tool in managing patients with organic MR.</AbstractText> |
9,551 | [Influence of age-related complications on clinical outcome in patients with surgical repair of atrial septal defect]. | The influence of perioperative characteristics on postoperative outcome has been obscure in the adult patients with atrial septal defect (ASD). This study was designed to investigate whether perioperative patient profiles and complications will contribute to postoperative outcome following surgical closure of ASD in adult patients.</AbstractText>Subjects were 39 (17 male and 22 female) ASD patients, aged 16 to 69 years (mean 53 +/- 15) who were scheduled for surgical repair of isolated secundum ASD between 1999 to 2003. All patients were evaluated for circulatory characteristics using echocardiography and cardiac catheterization. Postoperative complications were evaluated by examining duration of postoperative oxygen requirement, postoperative duration until first ambulation, intubation and hospital stay after surgery.</AbstractText>In elderly group (over 50 years of age), preoperative %FEV1.0, preoperative oxygen index and creatinine clearance were lower compared with those of younger group (under 50 years of age) (P=0.0309, P= 0.0341 and P= 0.0112, respectively). Moreover, elderly group showed longer duration of oxygen requirement compared with younger group (3 +/- 5 days and 2 +/- 1 days; P=0.0273). Age and change of the left ventricular diastolic diameter (LVDd) affected the incidence of postoperative arrhythmia (P=0.0195 and P=0.0204). Preoperative oxygen index and %VC affected long term intubation (P=0.0201 and P=0.0363). TAP, smoking and pulmonary hypertension affected long term oxygen supply (P=0.0070, 0.0349 and 0.0355). Only %VC affected postoperative duration until first ambulation (P = 0.0219). Delirium and postoperative oxygen index affected the length of hospitalization (P=0.0072 and 0.0188).</AbstractText>Respiratory function was important in short-term outcomes in the patients with ASD. In addition, preoperative small LVDd was a useful predictor for postoperative atrial fibrillation.</AbstractText> |
9,552 | Heart failure and diabetes: left ventricular systolic function. | Heart failure is the main cause of mortality and morbidity in general population, annual mortality rate is 20%, in spite of pharmacological treatments or other therapies. Cardio-vascular events and diabetes tight correlation is well known, while it is less evaluated diabetes and heart failure correlation is less studied, heart failure as left ventricular systolic function impairment. Cardiovascular disease rate is decreasing, systolic heart failure rate is raising. Our study goal is to evaluate which role diabetes plays in determining systolic heart failure, diagnosed by echocardiographical examination.</AbstractText>Four hundred and fifty consecutive patients, systolic heart failure prone, diagnosed by left ventricular ejection fraction less than 40%, were included. Exclusion criteria were rheumatic or congenital valve diseases. Mean age was 78.3 years (53-93 years), 286 were women and 164 men. Statistical analysis were performed by parametric t-Student test and not parametric chi2 test. High significant difference was assessed for P<0.05.</AbstractText>Seventy six (16.9%) patients were diabetes prone (D), 374 (83.1%) were diabetes free, so not diabetic (ND). Forty three men were D (56.5%), 131 ND (35%). Diabetic mean age was 74.7 years (52-88), not diabetic was 79.3 (53-93). Six D (7.8%) and 21 ND patients (5.6%) were hypercholesterolemia prone. Eight D (10.5%) and 18 ND (10.1%) patients were smokers. Twenty eight D (36.8%) and 107 ND patients (28.6%) were hypertensive. Thirty three D (43.4%) and 88 ND (26.4%) patients were coronary artery disease prone, 3 of 33 (3.9%) D and 28 of 88 (7.4%) ND ischemic patients were myocardial infarction prone. Twenty one D (27.6%) and 106 ND (28.3%) patients were atrial fibrillation prone. There were not statistical significant difference among D and ND patients for following variables: sex, smoke, total cholesterolemia, hypertension and atrial fibrillation. We found an high significant difference for mean age (P<0.005) and coronary artery disease prone patients (P<0.007), but not for myocardial infarction prone subjects (P<0.1).</AbstractText>Diabetes, not depending by other common cardiovascular risk factors, causes systolic heart failure, in prone patients, on an younger age, and in the same time an higher coronary artery disease rate, but not an higher myocardial infarction rate, because the coronary artery disease is often a microvascular one, and it leads to heart failure rather than myocardial necrosis.</AbstractText> |
9,553 | Brugada electrocardiographic pattern due to tricyclic antidepressant overdose. | The Brugada syndrome is an arrhythmogenic disease with characteristic coved ST-segment elevation 2 mm or greater in the right precordial leads (type 1 Brugada electrocardiogram [ECG] pattern or "Brugada sign"] and is estimated to be responsible for at least 20% of sudden deaths in patients with structurally normal hearts [Circulation 2005;111(5):659-70]. The Brugada sign has been described in asymptomatic patients after exposure to various drugs. As published reports of the drug-induced Brugada sign have become increasingly prevalent, there is growing interest in the mechanisms responsible for this acquired ECG pattern and its clinical significance. We report a case of a patient who developed the type 1 Brugada ECG pattern after intentional overdose of a tricyclic antidepressant agent, review the literature concerning tricyclic antidepressant agent-induced Brugada sign, discuss potential mechanisms, and evaluate the clinical significance of this ECG abnormality. |
9,554 | Shortening of the ventricular fibrillatory intervals after administration of verapamil in a patient with Brugada syndrome and vasospastic angina. | A 43-year-old man presented with electrocardiographic findings consistent with Brugada syndrome. Though the baseline coronary angiogram was normal, intracoronary infusion of ergonovine maleate caused complete occlusion of the left anterior descending and a 99% occlusion of the proximal right coronary artery, each relieved by intracoronary isosorbide dinitrate. Double extrastimuli delivered at the right ventricular outflow tract induced ventricular fibrillation terminated by a 200-J shock. Verapamil, 10 mg IV, increased ST-segment elevation and programmed stimulation repeated after the drug induced ventricular fibrillation with shorter F-F intervals and lower amplitude signals, which was not terminated by 200 J and required an additional 360-J shock. Ca2+ antagonism may have been adverse in this patient with Brugada syndrome because the drug has the potential to increase the voltage gradient through the right ventricle and to slow intraventricular conduction at very fast heart rates. |
9,555 | Beat-to-beat variations of the electrocardiogram in survivors of sudden death without structural heart disease. | We sought to determine whether survivors of sudden death without structural heart disease have beat-to-beat electrocardiographic (ECG) characteristics at the microvolt and at the millisecond level that differ from normal subjects.</AbstractText>We studied patients at our implantable cardioverter defibrillator clinic who had been resuscitated from ventricular fibrillation with no evidence of underlying structural heart disease. Continuous 10-minute high-resolution unfiltered digital surface ECGs at 1000-Hz sampling rate were acquired in these subjects and in a group of healthy volunteers. We then analyzed different parameters of beat-to-beat variations in duration, amplitudes and vectors of the QRS complex, and the T wave using a locally developed program (Comparative Analysis of ECGs, Vectocardiograms, and their Interpretation with Auto-Reference to the patient) and compared them between the 2 groups.</AbstractText>Thirteen patients (7 men; age, 46 +/- 16 years) were studied. Standard ECGs were unremarkable in 7 patients and suggestive of Brugada syndrome in the 6 others. The control group consisted of 23 age- and sex-matched subjects (13 men; age, 41 +/- 10 years). Although the QRS parameters showed only few differences between the 2 groups, there were several differences in parameters evaluating repolarization.</AbstractText>High-resolution ECGs show distinct beat-to-beat variations in parameters of repolarization in survivors of sudden death without structural heart disease, as compared with normal subjects. These findings may reflect increased electrical instability and should be evaluated for stratifying arrhythmic risk in asymptomatic individuals.</AbstractText> |
9,556 | [Time distribution of ventricular arrhythmias in patients with Brugada syndrome]. | To study the characterization of time distribution of ventricular arrhythmias in patients with Brugada syndrome (BrS) using Holter monitoring and ICD follow-up.</AbstractText>Patients with BrS [all male, mean age (41.07 +/- 11.49) years], were divided into ventricular fibrillation (VF) group (n = 7) and no ventricular fibrillation (N-VF) group (n = 7). Premature ventricular capture (PVC) and VF episodes were detected by Holter monitoring and ICD recording.</AbstractText>The 24 hours total number of PVCs ranged from 0 to 74 (mean 9.61 +/- 17.23) in most of the patients and were similar between VF group and N-VF group. The percentage of PVC episodes in VF group was significantly higher than that in N-VF group from nocturnal time to early morning (22:00 to 7:00, 98.67% vs. 44.14%, P < 0.01). There were total 75 VF episodes during (23.18 +/- 17.96) months' follow-up in 5 patients with BrS, 93.3% of which occurred from nocturnal time to early morning (22:00 to 7:00).</AbstractText>The episodes of PVC were enriched from nocturnal time to early morning in BrS patients, this time distribution could be a new noninvasive risk stratification factor for BrS. The episodes of VF in BrS patients were also enriched from nocturnal time to early morning and this time characteristic of episodes of VF could be used to guide drug therapy.</AbstractText> |
9,557 | Granulocyte colony-stimulating factor mediates cardioprotection against ischemia/reperfusion injury via phosphatidylinositol-3-kinase/Akt pathway in canine hearts. | Recent studies suggest that G-CSF prevents cardiac remodeling following myocardial infarction (MI) likely through regeneration of the myocardium and coronary vessels. However, it remains unclear whether G-CSF administered at the onset of reperfusion prevents ischemia/reperfusion injury in the acute phase. We investigated acute effects of G-CSF on myocardial infarct size and the incidence of lethal arrhythmia and evaluated the involvement of the phosphatidylinositol-3 kinase (PI3K) in the in vivo canine models.</AbstractText>In open-chest dogs, left anterior descending coronary artery (LAD) was occluded for 90 minutes followed by 6 hours of reperfusion. We intravenously administered G-CSF (0.33 micro/kg/min) for 30 minutes from the onset of reperfusion. Wortmannin, a PI3K inhibitor, was selectively administered into the LAD after the onset of reperfusion.</AbstractText>G-CSF significantly (p<0.05) reduced myocardial infarct size (38.7+/-4.3% to 15.7+/-5.3%) and the incidence of ventricular fibrillation during reperfusion periods (50% to 0%) compared with the control. G-CSF enhanced Akt phospholylation in ischemic canine myocardium. Wortmannin blunted both the infarct size-limiting and anti-arrhythmic effects of G-CSF. G-CSF did not change myeloperoxidase activity, a marker of neutrophil accumulation, in the infarcted myocardium.</AbstractText>An intravenous administration of G-CSF at the onset of reperfusion attenuates ischemia/reperfusion injury through PI3K/Akt pathway in the in vivo model. G-CSF administration can be a promising candidate for the adjunctive therapy for patients with acute myocardial infarction.</AbstractText> |
9,558 | Mechanism by which activation of delta-opioid receptor reduces the severity of postresuscitation myocardial dysfunction. | Postresuscitation myocardial dysfunction has been recognized as a leading cause of early death after initially successful cardiopulmonary resuscitation. We have previously demonstrated that opening adenosine triphosphate (ATP)-sensitive K (KATP) channels or activation of delta-opioid receptors minimized the severity of postresuscitation myocardial dysfunction and increased the duration of postresuscitation survival. In the present study, we investigated the potential mechanism of myocardial protection following delta-opioid receptor activation in a rat model of cardiac arrest and cardiopulmonary resuscitation.</AbstractText>Randomized prospective animal study.</AbstractText>Animal research laboratory.</AbstractText>Male Sprague-Dawley rats.</AbstractText>Ventricular fibrillation was induced in 24 Sprague-Dawley rats. Mechanical ventilation and precordial compression were initiated after 8 mins of untreated ventricular fibrillation. Defibrillation was attempted after 6 mins of cardiopulmonary resuscitation. The animals were randomized to four groups: a) pentazocine (0.3 mg/kg), a delta-opioid receptor agonist; b) pentazocine pretreated with KATP channel blocker, glibenclamide (0.3 mg/kg), administered 45 mins before induction of ventricular fibrillation; c) glibenclamide pretreated alone 45 mins before induction of ventricular fibrillation; and d) placebo. Pentazocine or saline placebo was injected into the right atrium after 5 mins of untreated ventricular fibrillation.</AbstractText>Postresuscitation myocardial function, as measured by the rate of left ventricular pressure increase at 40 mm Hg, left ventricular end-diastolic pressure, and cardiac index, was significantly improved in pentazocine-treated animals. This was associated with significantly prolonged duration of survival. Except for ease of defibrillation, the beneficial effects of pentazocine were abolished by pretreatment with the KATP channel blocker glibenclamide.</AbstractText>The postresuscitation myocardial protective effects provided by activation of delta-opioid receptor may be mediated via opening KATP channels.</AbstractText> |
9,559 | Effect of fish oil on ventricular tachyarrhythmia and death in patients with implantable cardioverter defibrillators: the Study on Omega-3 Fatty Acids and Ventricular Arrhythmia (SOFA) randomized trial. | Very-long-chain n-3 polyunsaturated fatty acids (omega-3 PUFAs) from fish are thought to reduce risk of sudden death, possibly by reducing susceptibility to cardiac arrhythmia.</AbstractText>To study the effect of supplemental fish oil vs placebo on ventricular tachyarrhythmia or death.</AbstractText><AbstractText Label="DESIGN, SETTING, AND PATIENTS" NlmCategory="METHODS">The Study on Omega-3 Fatty acids and ventricular Arrhythmia (SOFA) was a randomized, parallel, placebo-controlled, double-blind trial conducted at 26 cardiology clinics across Europe. A total of 546 patients with implantable cardioverter-defibrillators (ICDs) and prior documented malignant ventricular tachycardia (VT) or ventricular fibrillation (VF) were enrolled between October 2001 and August 2004. Patients were randomly assigned to receive 2 g/d of fish oil (n = 273) or placebo (n = 273) for a median period of 356 days (range, 14-379 days).</AbstractText>Appropriate ICD intervention for VT or VF, or all-cause death.</AbstractText>The primary end point occurred in 81 (30%) patients taking fish oil vs 90 (33%) patients taking placebo (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.64-1.16; P = .33). In prespecified subgroup analyses, the HR was 0.91 (95% CI, 0.66-1.26) for fish oil vs placebo in the 411 patients who had experienced VT in the year before the study, and 0.76 (95% CI, 0.52-1.11) for 332 patients with prior myocardial infarctions.</AbstractText>Our findings do not indicate evidence of a strong protective effect of intake of omega-3 PUFAs from fish oil against ventricular arrhythmia in patients with ICDs.</AbstractText>clinicaltrials.gov Identifier: NCT00110838.</AbstractText> |
9,560 | Critical time window for intra-arrest cooling with cold saline flush in a dog model of cardiopulmonary resuscitation. | Mild hypothermia improves outcome when induced after cardiac arrest in humans. Recent studies in both dogs and mice suggest that induction of mild hypothermia during cardiopulmonary resuscitation (CPR) greatly enhances its efficacy. In this study, we evaluate the time window for the beneficial effect of intra-arrest cooling in the setting of prolonged CPR in a clinically relevant large-animal model.</AbstractText>Seventeen dogs had ventricular fibrillation cardiac arrest no flow of 3 minutes, followed by 7 minutes of CPR basic life support and 50 minutes of advanced life support. In the early hypothermia group (n=9), mild hypothermia (34 degrees C) was induced with an intravenous fluid bolus flush and venovenous blood shunt cooling after 10 minutes of ventricular fibrillation. In the delayed hypothermia group (n=8), hypothermia was induced at ventricular fibrillation 20 minutes. After 60 minutes of ventricular fibrillation, restoration of spontaneous circulation was achieved with cardiopulmonary bypass for 4 hours, and intensive care was given for 96 hours. In the early hypothermia group, 7 of 9 dogs survived to 96 hours, 5 with good neurological outcome. In contrast, 7 of 8 dogs in the delayed hypothermia group died within 37 hours with multiple organ failure (P=0.012).</AbstractText>Early application of mild hypothermia with cold saline during prolonged CPR enables intact survival. Delay in the induction of mild hypothermia in this setting markedly reduces its efficacy. Our data suggest that if mild hypothermia is used during CPR, it should be applied as early as possible.</AbstractText> |
9,561 | Dual-chamber versus single-chamber detection enhancements for implantable defibrillator rhythm diagnosis: the detect supraventricular tachycardia study. | Delivery of inappropriate shocks caused by misdetection of supraventricular tachycardia (SVT) remains a substantial complication of implanted cardioverter/defibrillator (ICD) therapy. Whether use of optimally programmed dual-chamber ICDs lowers this risk compared with that in single-chamber ICDs is not clear.</AbstractText>Subjects with a clinical indication for ICD (n=400) at 27 participating centers received dual-chamber ICDs and were randomly assigned to strictly defined optimal single- or dual-chamber detection in a single-blind manner. Programming minimized ventricular pacing. The primary end point was the proportion of SVT episodes inappropriately detected from the time of programming until crossover or end of study. On a per-episode basis, 42% of the episodes in the single-chamber arm and 69% of the episodes in the dual-chamber arm were due to SVT. Mortality (3.5% in both groups) and early study withdrawal (14% single-chamber, 11% dual-chamber) were similar in both groups. The rate of inappropriate detection of SVT was 39.5% in the single-chamber detection arm compared with 30.9% in the dual-chamber arm. The odds of inappropriate detection were decreased by almost half with the use of the dual-chamber detection enhancements (odds ratio, 0.53; 95% confidence interval, 0.30 to 0.94; P=0.03).</AbstractText>Dual-chamber ICDs, programmed to optimize detection enhancements and to minimize ventricular pacing, significantly decrease inappropriate detection.</AbstractText> |
9,562 | Hyperviscosity as a possible risk factor for cerebral ischemic complications in atrial fibrillation patients. | Recent studies have suggested that hyperviscosity is frequent in patients with atrial fibrillation (AF). The aims of this study were to evaluate if hemorheologic alterations play a role in the occurrence of cerebral ischemic events in patients with AF and to explore a possible association between inflammation and hyperviscosity in these patients. Sixty-two patients with AF with a history of >or=1 cerebral ischemic event and 94 patients with AF without cerebral ischemic events were studied. A control population included 130 age- and gender-matched healthy volunteers. Hemorheologic variables (whole-blood viscosity, plasma viscosity, the erythrocyte deformability index, and hematocrit), fibrinogen, and high-sensitivity C-reactive protein levels were assayed. An alteration in whole blood viscosity at 94.5 seconds(-1) and the erythrocyte deformability index were found more frequently in patients with previous ischemic events on univariate and multivariate analyses (odds ratio 3.19, p=0.023 and odds ratio 4.26, p=0.002, respectively) adjusted for age, gender, hypertension, diabetes, history of coronary artery disease, left ventricular dysfunction, smoking habit, dyslipidemia, hematocrit, fibrinogen, high-sensitivity C-reactive protein, and hemorheologic parameters. These results should stimulate prospective studies on the role of hemorheologic alterations in the occurrence of cerebral ischemic complications in patients with AF. |
9,563 | Relation of right ventricular peak systolic pressure to major adverse events in patients undergoing cardiac resynchronization therapy. | The degree to which increased right-sided heart pressures influence outcome in cardiac resynchronization therapy (CRT) is unclear. High right ventricular (RV) pressures may contribute to septal malpositioning, thus hindering effective resynchronization. We hypothesized that patients with high RV systolic pressures before CRT implantation would have poorer outcome. We evaluated echocardiograms, electrocardiograms, and clinical records from 75 consecutive patients with CRT. RV systolic pressure was calculated from the peak tricuspid regurgitant, time-velocity profile. The primary end point was a composite of mortality, cardiac transplantation, or need for a left ventricular assist device. Events were evaluated by Kaplan-Meier curves and Cox proportional hazard ratios. Patients grouped by RV systolic pressure divided at the median of 35 mm Hg were similar except for more renal insufficiency and RV dysfunction when RV systolic pressure was >35 mm Hg. Univariate analysis identified RV systolic pressure >35 mm Hg (hazard ratio [HR] 3.32), diabetes (HR 2.45), renal insufficiency (HR 3.52), atrial fibrillation (HR 3.07), use of nonamiodarone antiarrhythmic medications (HR 2.86), atrial pacing (HR 2.57), and prolonged PR interval (HR 1.009) as associated with poorer outcome. Normal sinus rhythm at implantation (HR 0.34), baseline left bundle branch block (HR 0.44), and beta-blocker use (HR 0.47) were associated with improved outcome. In a multivariable model, high RV systolic pressure (HR 3.71, 95% confidence interval 1.31 to 10.4), renal insufficiency (HR 3.18, 95% confidence interval 1.29 to 7.86), and atrial fibrillation (HR 4.22, 95% confidence interval 1.54 to 11.6) remained significant. In conclusion, despite resynchronization, patients with high RV pressures have significantly decreased survival after adjusting for significant contributing influences. |
9,564 | Short-term triple therapy with aspirin, warfarin, and a thienopyridine among patients undergoing percutaneous coronary intervention. | To assess bleeding complications among patients undergoing percutaneous coronary intervention (PCI) and receiving triple therapy of warfarin, aspirin, and a thienopyridine.</AbstractText>Triple therapy of warfarin, aspirin, and a thienopyridine is strongly discouraged, given the potential risk of bleeding complications.</AbstractText>Post-PCI patients receiving triple therapy thereafter underwent assessment for bleeding complications. Continuous variables are presented as median (25th-75th percentiles). The study group included 180 patients (80% males; age 65 (52, 75.5)). PCI was on an urgent/emergent basis in 86.6%. The main indications for warfarin use were left ventricular mural thrombus and atrial fibrillation (46.9 and 36.9% respectively). Glycoprotein IIb/IIIa receptor antagonists were used in 47.7%. Post-PCI triple therapy duration was 30 days (30, 30). During the post-triple therapy, 104 patients (57.8%) continued treatment with warfarin and aspirin for 376 days (150, 775). During the triple therapy period, 20 patients developed bleeding complications, (mean INR 2.1 +/- 0.7 at 7 (6, 8.5) days post-PCI): 2 major groin hematoma (initial phase of warfarin treatment during overlap with heparin) and 18 minor. During post-triple therapy, primarily under warfarin and aspirin, 19 patients developed bleeding complications: 1 major and 18 minor.</AbstractText>Short-term triple therapy after PCI was not associated with prohibitively high bleeding complication rates, and thus should be favorably considered in patients with a clear indication for warfarin use.</AbstractText>Copyright 2006 Wiley-Liss, Inc.</CopyrightInformation> |
9,565 | The prognostic value of big endothelin-1 in more than 2,300 patients with heart failure enrolled in the Valsartan Heart Failure Trial (Val-HeFT). | Endothelin is elevated in heart failure and contributes to neurohormonal activation, hemodynamic deterioration, and cardiovascular remodeling. Here, we examined its prognostic value in a large population of patients with chronic heart failure.</AbstractText>Big endothelin-1 (Big ET-1) and 4 other neurohormones were measured at study entry in 2359 patients enrolled in the Valsartan Heart Failure Trial (Val-HeFT) and their concentrations related to outcome over a median follow-up of 23 months. Baseline concentration of Big ET-1 (median 0.80 pmol/L) was proportional to severity of disease (New York Heart Association class, left ventricular structure and function). High circulating concentrations of brain natriuretic peptide (BNP), creatinine and bilirubin, advanced New York Heart Association class, elevated body mass index, and the presence of atrial fibrillation were independently associated to higher concentrations of Big ET-1. Big ET-1 (ranking second just behind BNP among neurohormonal factors) was an independent predictor of outcome defined as all-cause mortality (hazard ratio 1.49, 95% CI 1.20-1.84, P = .0003) or the combined endpoint of mortality and morbidity (hazard ratio 1.43, 95% CI 1.20-1.69, P < .0001) and provided incremental prognostic value compared with BNP.</AbstractText>In a large population of patients with symptomatic heart failure, the circulating concentration of Big ET-1, a precursor of the paracrine and bioactive peptide ET-1, was an independent marker of mortality and morbidity. In this setting, BNP remained the strongest neurohormonal prognostic factor.</AbstractText> |
9,566 | Energy doses for treatment of out-of-hospital pediatric ventricular fibrillation. | To investigate the energy dose used to treat out-of-hospital pediatric ventricular fibrillation and the survival rates of these patients.</AbstractText>We reviewed three emergency medical systems (EMS) for their reports of patients under 1 month to 18 years who received shocks for ventricular fibrillation to determine the energy of each shock as well as other patient and care characteristics. Each patient's weight was estimated at the age-appropriate 50th and 95th percentiles. Patients were then grouped as receiving recommended energy doses (2 to < or = 4 J/kg), moderately high energy doses (> 4-6 J/kg), and high energy doses (> 6 J/kg).</AbstractText>Of 57 patients identified, 54% were male, with a mean age of 11 years, range 2 months to 17 years. Ventricular fibrillation was the initial rhythm in 80% (43/54) of patients. The mean number of shocks delivered was 3, with < or = 2 shocks delivered to 28 (49%) and > or = 5 shocks delivered to 10 (18%) patients. When evaluating all 185 shocks using the 50th percentile estimated weight, 45 (24%) shocks were at recommended doses, 56 (30%) were at moderately high energy doses, and 84 (45%) were high energy doses. Elevated energy dose was associated with an increasing number of shocks and lack of bystander CPR (p < .05). Nineteen (33%) patients survived to hospital discharge having received total doses up to 73 J/kg. Energy dose was not related to survival.</AbstractText>In this observational, multicenter out of hospital experience, children received a wide range of defibrillation doses, often exceeding recommended doses and equivalent to adult energy levels. Survival occurred at low and very high energy doses.</AbstractText> |
9,567 | General anesthesia with thoracic epidural anesthesia in the cardiopulmonary bypass surgery reduces apoptosis by upregulating antiapoptotic protein Bcl-2. | The aim of the paper was to investigate whether thoracic epidural anesthesia (TEA) together with general anaesthesia (GA) play a role on apoptosis in humans before cardiopulmonary bypass (CPB), before aortic cross clamp (ACC) and at 15 min after ACC release (after ischemia and reperfusion).</AbstractText>Eighty patients scheduled for elective CABG were randomized to receive either GA group (n: 40) or TEA+GA group (n: 40). The right atrial biopsy samples were taken before CPB, before ACC and at 15 min after ACC release from all patients. Human heart tissues were obtained from patients of TEA+GA group and GA group. The number of Bcl-2 positive cardiomyocytes was counted in multiple tissue sections of biopsies of 80 patients using light microscopy (magnification x 40) with an ocular micrometer system (Olympus).</AbstractText>In the TEA+GA group, the Bcl-2 positive cardiomyocytes were distinctly statistically increased compared to the GA group (P<0.001). In addition, the intensity of the immunostaining was also increased in the TEA+GA compared with the GA group. The number of immunoreactive cardiomyocytes is as follows: before CPB, TEA+GA group 396+/-61, GA group 92+/-41, before ACC, TEA+GA group 333+/-47, GA group 94+/-18, at 15 min after ACC release, TEA+GA group 346+/-68.8, GA group 85+/-9.5. There were statistically significant differences between groups, (P<0.001). Between groups, at 4 h and at 24 h after the end of CPB, in the TEA+GA group, the CI was significantly higher than GA group respectively; (3.4+/-0.8 L/min/m(2) vs 2.5+/-0.8 L/min/m(2); P<0.001), (3.8+/-1.1 L/min/m(2) vs 3.1+/-1.1 L/min/m(2); P<0.008). Within groups, at 4 and 24 h after the end of CPB, in the TEA+GA group, the CI was significantly higher than baseline values, respectively, (3.4+/-0.8 L/min/m(2) vs 2.4+/-0.7 L/min/m(2); P<0.001), (3.8+/-1.1 L/min/m(2) vs 2.4+/-0.7 L/min/m(2); P<0.001). Whereas no difference was found in the GA group respectively, (2.6+/-0.8 L/min/m(2) vs. 2.5+/-0.8 L/min/m(2); P>0.05), (2.6+/-0.8 L/min/m(2) vs. 3.1+/-1.1 L/min/m(2); P>0.05). The number of patients showing ventricular fibrillation (VF), atrial fibrillation or heart block after release of the ACC was 11 of 40 (27.5%) in the TEA+GA group versus 25 of 40 (62.5%) in the GA group. The number of patients showing VF after release of ACC was 9 out of 20 patients (22.5%) in the TEA+GA group which was significantly lower than in the GA group (21 of 40 patients 52.5%); (P<0.006). Sinus rhythm after release of ACC, in the TEA+GA group was observed in 29 of 40 patients (72.5%) and was significantly higher than in the GA group (15 of 40 patients 37.5%); (P<0.002).</AbstractText>The result of the present study indicate that TEA plus GA in coronary surgery had preserved cardiac function during intraoperative and postoperative period by means of reduced apoptosis, improved hemodynamic function and reduced arrhythmias after release of the ACC.</AbstractText> |
9,568 | Thromboembolic complications in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy. | Incidence and clinical presentation of thromboembolic complications in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) were analysed. In reports on ARVD/C, thromboembolism is rarely mentioned. The possible risk factors are: right ventricle (RV) dilatation, aneurysms, and wall motion abnormalities.</AbstractText>A group of 126 patients (89 male, 37 female, aged 43.6+/-14.3) with ARVD/C was retrospectively analysed for the presence of thromboembolic complications. The mean follow-up period was 99+/-64 months. Thromboembolic complications, i.e. pulmonary embolism (n=2), RV outflow tract thrombosis with severe RV failure (n=1), and cerebrovascular accident associated with atrial fibrillation (n=2) were observed in 4% of the patients. Spontaneous echogenic contrast was observed in seven patients with severe damage to RV. In four of them supraventricular arrhythmias resulting in heart failure were reported. Annual incidence of thromboembolic complications was 0.5/100 patients.</AbstractText>(i) ARVD/C may be complicated by thrombosis. Annual incidence of such complications is significantly lower than reported for left ventricle failure. (ii) Anticoagulation should be used in ARVD/C patients with large, hypokinetic RV and slow blood flow. (iii) Patients with severe forms of ARVD/C, thrombus formation in the RV and/or spontaneous echocardiographic contrast are at higher risk of a poor outcome.</AbstractText> |
9,569 | Sudden cardiac death: directing the scope of resuscitation towards the heart and brain. | The fundamental goal of cardiopulmonary resuscitation (CPR) is recovery of the heart and the brain. This is best achieved by (1) immediate CPR for coronary and cerebral perfusion, (2) correction of the cause of cardiac arrest, and (3) controlled cardioplegic cardiac reperfusion. Failure of such an integrated therapy may cause permanent brain damage despite cardiac resuscitation.</AbstractText>This strategy was applied at four centers to 34 sudden cardiac death patients (a) after acute myocardial infarction (n = 20), (b) "intraoperatively" following successful discontinuation of cardiopulmonary bypass (n = 4), and (c) "postoperatively" in the surgical ICU (n = 10). In each witnessed arrest the patient failed to respond to conventional CPR with ACLS interventions, including defibrillation. The cardiac arrest interval was 72 +/- 43 min (20-150 min). Compression and drugs maintained a BP > 60 mmHg to avoid cerebral hypoperfusion. Operating room (OR) transfer was delayed until the blood pressure was monitored. In four patients femoral bypass maintained perfusion while an angiographic diagnosis was made.</AbstractText>Management principles included no repeat defibrillation attempts after 10 min of unsuccessful CPR, catheter-monitored peak BP > 60 mmHg during diagnosis and transit to the operating room, left ventricular venting during cardiopulmonary bypass and 20 min global and graft substrate enriched blood cardioplegic reperfusion. Survival was 79.4% with two neurological complications (5.8%).</AbstractText>Recovery without adverse neurological outcomes is possible in a large number of cardiac arrest victims following prolonged manual CPR. Therapy is directed toward maintaining a monitored peak BP above 60 mmHg, determining the nature of the cardiac cause, and correcting it with controlled reperfusion to preserve function.</AbstractText> |
9,570 | Cigarette smoking and the risk of supraventricular and ventricular tachyarrhythmias in high-risk cardiac patients with implantable cardioverter defibrillators. | Nicotine elevates serum catecholamine concentration and is therefore potentially arrhythmogenic. However, the effect of cigarette smoking on arrhythmic risk in coronary heart disease patients is not well established.</AbstractText>The risk of appropriate and inappropriate defibrillator therapy by smoking status was analyzed in 717 patients who received an implantable cardioverter defibrillator (ICD) in the Multicenter Automatic Defibrillator Implantation Trial-II. Compared with patients who had quit smoking before study entry (past smokers) and patients who had never smoked (never smokers), patients who continued smoking (current smokers) were significantly younger and generally had more favorable baseline clinical characteristics. Despite this, the adjusted hazard ratio (HR) for appropriate ICD therapy for fast ventricular tachycardia (at heart rates >or=180 b.p.m) or ventricular fibrillation was highest among current smokers (HR = 2.11 [95% CI 1.11-3.99]) and intermediate among past smokers (HR = 1.57 [95% CI 0.95-2.58]), as compared with never smokers (P for trend = 0.02). Current smokers also exhibited a higher risk of inappropriate ICD shocks (HR = 2.93 [95% CI 1.30-6.63]) than past (HR = 1.91 [95% CI 0.97-3.77]) and never smokers (P for trend = 0.008).</AbstractText>In patients with ischemic left ventricular dysfunction, continued cigarette smoking is associated with a significant increase in the risk of life-threatening ventricular tachyarrhythmias and inappropriate ICD shocks induced by rapid supraventricular arrhythmias. Our findings stress the importance of complete smoking cessation in this high-risk population.</AbstractText> |
9,571 | Delayed enhancement cardiac MR imaging in noncompaction of left ventricular myocardium. | A 49-year-old female with a history of paroxysmal atrial fibrillation, presented with worsening dyspnea on minimal exertion. During the follow-up period, transthoracic echocardiography and cardiac magnetic resonance imaging (CMR) were consistent with the diagnosis of noncompaction of the left ventricle. Delayed-enhancement CMR demonstrated hyperenhancement of the prominent trabeculations located at the mid and apical portions of the left ventricle, suggesting areas of fibrosis. Although previous cases of left ventricular noncompaction diagnosed with CMR have been described in the literature, this is the first case to describe the utility of delayed-enhancement imaging in the pathohistological confirmation of myocardial fibrosis and scarring in the hypertrabeculated myocardium. |
9,572 | Systolic outward motion of the left ventricular apical wall as detected by magnetic resonance tagging in patients with apical hypertrophic cardiomyopathy. | Patients with apical hypertrophic cardiomyopathy (APH) associated with paradoxic jet flow (ie, diastolic flow away from the apex) may gradually develop an apical aneurysm, which often leads to arrhythmia and mural thrombus formation. We observed systolic outward motion of the left ventricular apical myocardium in patients with APH using a magnetic resonance tagging procedure and examined the relationship of the outward motion to echocardiographic and scintigraphic findings and to cardiac events. Systolic displacement of the myocardial tags of the apical region perpendicular to the long axis in the 4-chamber view was recorded in 31 patients with APH. Of these patients, 14 showed no outward movement of tags (group A), and 17 showed outward movement (group B). In group B, apical hypertrophy was more severe (35 +/- 7 mm vs. 29 +/- 6 mm, p < 0.05), paradoxic jet flow was more frequent (64% vs. 14%, p < 0.05) and the defect score in I-123-beta-methyliodophenylpentadecanoic acid scintigraphy was higher (2.1 +/- 0.7 vs. 1.3 +/- 0.7, p < 0.01). During a mean follow-up period of 55 months, only 1 patient experienced paroxysmal atrial fibrillation in group A. In group B, 1 patient died suddenly, 1 was admitted to hospital because of congestive heart failure, 2 developed angina pectoris, 2 exhibited non-sustained ventricular tachycardia, and 1 showed multifocal premature ventricular contraction; in these 7 patients the outward movement was greater than in the 10 patients in Group B who had no cardiac events (1.00 +/- 0.59 vs. 0.52 +/- 0.40, p < 0.05). Hence, our results show that outward tag displacement is frequently associated with severe apical hypertrophy, paradoxic jet flow, apical ischemia, and cardiac events. The tagging method may be useful in assessing the severity of APH and predicting the occurrence of cardiac events at an early stage. |
9,573 | Risk factors for atrial fibrillation in adult patients in long-term observation following surgical closure of atrial septal defect type II. | The aim of the study was to find the factors predictive for paroxysmal atrial fibrillation (AF) following surgical correction of atrial septal defect type II (ASD t.II).</AbstractText>93 patients, who underwent isolated surgical closure of ASD t.II between 1990 and 2001 were included. Follow-up studies were performed 2 - 11 years after surgery. Patients were divided into two groups according to the presence of AF before and after surgery. Group AF (+) consisted of 29 and group AF (-) of 64 patients. All patients underwent echocardiography, electrocardiogram (ECG) at rest, and signal-averaged P-wave duration (PWD) in signal-averaged ECG. The following parameters were assessed in echocardiography: pulmonary artery systolic pressure, left and right atrial dimensions, right ventricular dimension, tricuspid and mitral regurgitation.</AbstractText>Paroxysmal AF was observed in 27 patients before surgery and in 29 after surgery. Analyzing all potential risk factors we proved that PWD may independently predict occurrence of postoperative AF.</AbstractText>PWD may independently predict postoperative AF in long-term follow-up after surgical correction of ASD t.II.</AbstractText> |
9,574 | Sudden death is associated with a widened paced QRS complex in noncoronary cardiac disease. | Recent experimental and clinical trials have provided evidence that increased duration of right ventricular electrogram in response to premature extrastimuli correlates with the risk of ventricular fibrillation in noncoronary heart disease. The aim of the present study was to investigate the duration of the surface QRS complex at short coupling intervals of extrastimuli as a new indicator for major arrhythmic events.</AbstractText>32 patients all with nonischemic heart diseases and well preserved left ventricular function in sinusrhythm were included into the study. Fifteen had witnessed sudden death due to ventricular fibrillation or polymorphic ventricular tachycardia (VF/VT group). The control group comprised seventeen patients without a history of ventricular arrhythmias (control group). All subjects underwent programmed ventricular stimulation and QRS-durations S1-S2-S3 directly above the ventricular refractory period were analyzed.</AbstractText>Both groups had a comparable basic QRS complex of 85 +/- 9 (VF/VT) vs. 87 +/- 13 ms (control), p = 0.83. The stimulated QRS complex S3 was significantly wider in the VF/VT group compared to the control group at pacing rates of 500 and 430 ms (500 ms: 256 +/- 22 vs. 235 +/- 32 ms, p = 0.04; 430 ms: 258 +/- 23 vs. 226 +/- 27 ms, p = 0.001). No differences with regard to the ventricular effective refractory period and the ventriculoatrial conduction could be observed beween the groups.</AbstractText>Our results indicate that the duration of the paced QRS complex may be a valuable parameter to predict arrhythmic risk in patients with nonischemic heart disease. Further prospective studies in larger trials are necessary to corroborate this investigation.</AbstractText> |
9,575 | Clinical trials, the renin angiotensin system and atrial fibrillation. | Atrial fibrillation is the most common clinical arrhythmia. Current treatment strategies are far from optimal. One new research direction is to target the atrial fibrillation substrate and to examine whether drugs can produce atrial structural and/or electrophysiological remodeling and whether this results in a reduction in atrial fibrillation burden.</AbstractText>Two prospective randomized studies have shown that the addition of an angiotensin converting enzyme inhibitor or an angiotensin receptor blocker to amiodarone reduces the recurrence rate of atrial fibrillation after electrical cardioversion. There are ten completed prospective clinical trials with atrial fibrillation as a secondary endpoint or assessed in post-hoc analysis. Five of these studies have reported a positive impact of angiotensin converting enzyme inhibitors or angiotensin receptor blockers on atrial fibrillation burden. A meta-analysis showed that active drugs reduced the overall risk of development of atrial fibrillation by 28%. Patients in the heart failure trials obtained most benefit from these drugs (relative risk reduction 44%, P = 0.07).</AbstractText>The initial basic science and clinical trial data suggest that modulation of the renin angiotensin system may be an effective treatment for atrial fibrillation. The following, however, remain to be clarified: do these drugs have a clinically meaningful impact on atrial fibrillation burden; if there is an impact, is it similar in all atrial fibrillation patients or just in certain subsets; do angiotensin converting enzyme inhibitors and angiotensin receptor blockers have similar benefits; and is there a role for aldosterone antagonists?</AbstractText> |
9,576 | One-shock versus three-shock defibrillation protocol significantly improves outcome in a porcine model of prolonged ventricular fibrillation cardiac arrest. | The success of resuscitation with a 1-shock versus the conventional 3-shock defibrillation protocol was investigated subject to the range of treatment variation imposed by automated external defibrillators (AEDs).</AbstractText>Ventricular fibrillation was induced in 44 domestic pigs. After 7 minutes of untreated VF, animals were randomized among 4 groups representing all combinations of the 1- versus 3-shock protocol and 2 different AED regimens (AED1, AED2). Because few AEDs support a 1-shock protocol, manual defibrillators were used to replicate the AED treatment regimen: electrical waveform, dose sequence, and cardiopulmonary resuscitation (CPR) interruption intervals. Initial shock(s) were delivered, followed by 60 seconds of CPR, and the treatment was repeated until resuscitation was successful or for 15 minutes. The 1-shock protocol was associated with improved outcome, reducing CPR interruptions from 45% to 34% of total resuscitation time (P=0.019) and increasing survival from 64% to 100% (P=0.004). Survival was 91% for AED1 versus 36% for AED2 (P=0.024) with a 3-shock protocol but was increased to 100% for both by adoption of a 1-shock protocol. Improvements in postresuscitation left ventricular ejection fraction and stroke volume were observed with AED1 compared with AED2 (difference of means, 15% and 28% of baseline respectively, P<0.001) regardless of defibrillation protocol.</AbstractText>Adoption of a 1-shock versus a 3-shock resuscitation protocol improved survival and minimized outcome differences imposed by variations in AED design and implementation. When a conventional 3-shock defibrillation protocol was used, however, the choice of AED had a significant impact on resuscitation outcome.</AbstractText> |
9,577 | Left ventricular outflow tract obstruction and sudden death risk in patients with hypertrophic cardiomyopathy. | Left ventricular outflow tract obstruction (LVOTO) is associated with reduced survival in patients with hypertrophic cardiomyopathy (HCM). The influence of LVOTO on survival from SD in relation to other recognized clinical risk markers is unknown.</AbstractText>A total of 917 patients with HCM (554 males, 43+/-15 years) were studied; 288 (31.4%) had LVOTO at rest (> or =30 mmHg). During follow-up [median 61 (30;99) months], 54 (5.9%) patients died suddenly (SD), survived ventricular fibrillation, or had an appropriate ICD discharge; 25 (2.7%) died from heart failure or were transplanted; 17 (1.8%) died from other cardiovascular causes. Five-year survival from all-cause death or cardiac transplantation was lower in patients with LVOTO [86.5% (95% CI: 81.7-91.2) vs. 90.1% (95% CI: 87.3-92.8), P=0.006], with a trend towards higher all-cause death and transplantation with increasing LVOTO [(RR per 20 mmHg=1.24 (95% CI: 1.08-1.42), P=0.003)]. In patients with obstruction, there was a significant relation between 5-year survival from all-cause death and functional limitation (NYHA class I: 91.0%; NYHA class II: 83.3%; NYHA class III/IV: 82.6%, P=0.002). LVOTO was associated with reduced survival from SD and ICD discharge (SD/ICD) [91.4% (95% CI: 87.4-95.3) vs. 95.7% (95% CI: 93.8-97.6), P=0.0004]. Magnitude of LVOTO was related to a higher occurrence of SD/ICD [RR per 20 mmHg=1.36 (95% CI: 1.12-1.65), P=0.001]. There was no relation between survival from SD/ICD, LVOTO, and NYHA class. The annual rate of SD/ICD in patients with LVOTO and no risk factors was 0.37% (95%CI: 0.05-1.35). There was a trend towards lower survival from SD/ICD, with increasing numbers of risk factors in patients with and without LVOTO (P=0.002 and P=0.002, respectively). Multivariable analysis demonstrated that LVOTO was an independent predictor of SD/ICD, with a 2.4-fold (P=0.003) increase in the risk of SD/ICD.</AbstractText>LVOTO is associated with an increased risk of SD/ICD that is related to the severity of obstruction and the presence of other recognized risk factors for SD. The low sudden death mortality in asymptomatic patients with LVOTO and no other SD risk markers suggests that aggressive interventions to reduce LVOTO are unwarranted in this group. Further studies are required to determine the most appropriate treatment strategies (ICD or gradient reduction) in patients with additional risk factors.</AbstractText> |
9,578 | [Acute myocardial infarction complicated by cardiogenic shock. Difficult decision concerning long-distance transportation to a tertiary centre -- a case report]. | A case of a 60-year-old female with acute myocardial infarction complicated by cardiogenic shock is presented. The patient received thrombolytic therapy, however, developed cardiogenic shock and required resuscitation with intubation, mechanical ventilation and repeated defibrillation due to recurrent ventricular fibrillation. The patient was transported by air to the tertiary centre with catheterisation laboratory (distance -- 120 km), where successful angioplasty with stent implantation in the right coronary artery was performed. Difficulties in transportation of patients with fully-developed cardiogenic shock are discussed. |
9,579 | Percutaneous coronary intervention for cardiac arrest secondary to ST-elevation acute myocardial infarction. Influence of immediate paramedical/medical assistance on clinical outcome. | Patients with cardiac arrest have been excluded from most randomized trials on percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).</AbstractText>The aim of the study was to evaluate the outcome of patients undergoing primary PCI for acute myocardial infarction who suffered from cardiac arrest prior to the procedure, focusing the study on the influence of immediate paramedical-medical assistance on the outcome.</AbstractText>Sixty-three patients with ST-elevation AMI and previous cardiac arrest underwent primary PCI within 12 hours after symptom onset. Three groups of patients were defined: Group 1: Cardiac arrest before hospital admission, without immediate (< 1 minute) initiation of resuscitation maneuvers (n = 13); Group 2: Pre-hospital cardiac arrest with immediate initiation of resuscitation maneuvers (n = 14); Group 3: Cardiac arrest after hospital admission. The proportion of patients with ventricular tachycardia or fibrillation as documented initial rhythm was similar among the groups (77%, 79% and 83%, respectively), as well as the rate of angiographic success (92%, 93% and 86%, respectively). However, the incidence of cardiac events at 30 days was significantly higher in Group 1 than in Groups 2 or 3 (54%, 29% and 17%, respectively; p = 0.03), as well as the mortality rate at 30 days (46%, 21% and 18%, respectively; p = 0.06). Interestingly, the outcomes were not statistically different between Groups 2 and 3. In multivariate analysis, the independent predictors for mortality at 30 days for Group 1 were: multivessel disease, angiographic failure and cardiogenic shock.</AbstractText>Combining immediate initiation of resuscitation maneuvers and primary PCI yields a very good clinical outcome in patients with AMI suffering from cardiac arrest.</AbstractText> |
9,580 | Clinical outcomes in patients undergoing elective coronary artery bypass graft surgery with and without utilization of pulmonary artery catheter-generated data. | The purpose of this study was to determine the frequency of pulmonary artery catheter (PAC) quantitative data requirements for modifying patient management during and after elective coronary artery bypass graft (CABG) surgery.</AbstractText>A prospective observational clinical trial.</AbstractText>University tertiary referral center.</AbstractText>Two hundred patients undergoing elective CABG surgery.</AbstractText>Attending anesthesiologist and surgeon were blinded to PAC numeric values. These data could be revealed in the presence of at least 2 of the following criteria: (1) systolic blood pressure <90 mmHg, (2) central venous pressure >15 mmHg, (3) urine output <0.5 mL/kg/h, (4) pH <7.35/HCO(3) <18 mmol/L, (5) SaO(2) <95%/F(I)O(2) >80%, and (6) ST changes +/- 2 mm if the empiric treatment failed to restore normal hemodynamics within 10 minutes. All patients were classified into either blinded or unblinded PAC groups.</AbstractText>PAC data were unblinded in 46 (23%) patients. Preliminary diagnosis was confirmed in 28 (14%), and treatment was modified in 18 (9%) of these patients. Four (2%) patients were given additional fluid challenges, 10 (5%) patients received a combination of fluid challenges and inotropic support, 3 (1.5%) patients were started on vasoconstrictors, and 1 (0.5%) patient required insertion of an intra-aortic balloon pump. Patients in the unblinded PAC group had a higher prevalence of perioperative myocardial infarction, atrial fibrillation, and inotropic support; longer intubation times; and increased intensive care unit (ICU) and hospital lengths of stay.</AbstractText>This study confirmed the contention that insertion of a PAC can be safely delayed until the clinical need arises either in the operating room or in the ICU after elective CABG surgery.</AbstractText> |
9,581 | Treatment crossovers did not affect randomized treatment comparisons in the Mode Selection Trial (MOST). | We evaluated the impact of treatment crossovers on study results in the Mode Selection Trial (MOST).</AbstractText>The MOST study, a 2,010-patient, 6-year trial comparing dual-chamber pacing (DDDR) and ventricular pacing (VVIR) in sinus node dysfunction, demonstrated no difference in death or stroke and modest reductions in heart failure hospitalization (HFH) and atrial fibrillation (AF) with DDDR pacing. However, a moderate proportion of VVIR-randomized patients were temporarily or permanently crossed over to DDDR pacing.</AbstractText>Intent-to-treat (ITT) analyses compared treatment arms by randomized pacing mode. On-treatment analyses used time-dependent covariates to account for all crossovers. All analyses used Cox proportional hazards models and included covariates prespecified in the study design: age, gender, Charlson index, and prior stroke, heart failure, myocardial infarction, supraventricular tachyarrhythmia, and ventricular tachycardia or fibrillation.</AbstractText>Of 996 VVIR-randomized patients, 375 (38%) were DDDR paced at some time, accounting for 27% of follow-up days among all VVIR-randomized patients. Of 1,014 DDDR-randomized patients, 53 (5%) were VVIR paced at some time, accounting for 1.5% of follow-up days among all DDDR-randomized patients. On-treatment analyses showed slightly lower hazard ratios favoring DDDR versus VVIR compared with ITT: death or stroke 0.88 (on-treatment) versus 0.91 (ITT); death 0.94 versus 0.95; stroke 0.74 versus 0.81; HFH 0.72 versus 0.73; and AF 0.72 versus 0.77. Interpretation of treatment effects was unchanged.</AbstractText>Although treatment crossovers accounted for >25% of follow-up time in the VVIR-randomized group, this did not affect study results. End point comparisons between randomized modes are accurate reflections of DDDR versus VVIR pacing in this study population.</AbstractText> |
9,582 | Valvular aortic stenosis: disease severity and timing of intervention. | Standard echocardiographic evaluation of aortic stenosis (AS) severity includes measurement of aortic velocity, mean transaortic pressure gradient, and continuity equation valve area. Although these measures are adequate for decision making in most patients, there is no single value that defines severe stenosis. Aortic stenosis affects not just the valve, but the entire vascular system, including the left ventricle (LV) and systemic vasculature. More sophisticated measures of disease severity might explain the apparent overlap in hemodynamic severity between symptomatic and asymptomatic patients and might better predict the optimal timing of valve replacement. There have been several approaches to evaluation of stenosis severity based on valve hemodynamics, the ventricular response to increased afterload, ventricular-vascular coupling, or the systemic functional consequences of valve obstruction, such as exercise testing and serum brain natriuretic peptide levels. Aortic valve replacement is indicated when symptoms due to severe AS are present. In most asymptomatic patients, the risk of surgery is greater than the risk of watchful waiting so that management includes patient education, periodic echocardiography, and cardiac risk factor modification. Many adults with AS have comorbid conditions that affect both the diagnosis and management of the valve disease, including aortic regurgitation, aortic root dilation, hypertension, coronary artery disease, LV dysfunction, and atrial fibrillation. Comorbid conditions should be evaluated and treated based on established guidelines, although awareness of the potential effects of therapy in the presence of valve obstruction is needed. |
9,583 | Costs, clinical outcomes, and health-related quality of life of off-pump vs. on-pump coronary bypass surgery. | Off-pump coronary bypass surgery avoids the potential complications of cardiopulmonary bypass. However, its acceptance depends on medical and economic outcome. The aim of this prospective non-randomised study was to compare functional and economic outcome of off-pump and on-pump surgery at 1-year follow-up.</AbstractText>102 patients (pts) treated with either off-pump (60pts) or on-pump surgery (42pts) were studied. Pts with left ventricular dysfunction, recent myocardial infarction (<1 month), renal impairment, valve surgery, previous stroke or coagulopathy were excluded. Variable and fixed costs were obtained for each treatment group during operative and postoperative care. In-hospital endpoints included all-cause mortality and complications (defined as excessive bleeding [>6 units blood transfusion], peri-operative myocardial infarction, atrial fibrillation, stroke, and infection). All cause mortality; cost-effectiveness and quality of life were assessed 1 year after surgery.</AbstractText>The in-hospital mortality was similar in the two treatment groups. Off-pump group had significantly fewer postoperative complication rate (off-pump 41% vs. on-pump 72%, p=0.001). The mean in-hospital cost was lower for off-pump surgery (off-pump 6.515+/-926 euro vs. on-pump 9.872+/-1.299 euro, p<0.0001) as well as the mean length of hospital stay (off-pump 4.93+/-0.93 days vs. on-pump 6.58+/-1.04 days, p<0.0001). At 1 year, all cause mortality, quality of life indices, return to work rate and treatment satisfaction was similar in both groups.</AbstractText>Off-pump myocardial revascularization maintains the advantages of conventional surgery in terms of survival and freedom from cardiac events while reducing the in-hospital cost.</AbstractText> |
9,584 | Short-term effect of rate control on plasma endothelin levels of patients with tachyarrhythmias. | Radiofrequency catheter ablation or modification of the atrio-ventricular junction is an effective therapy of drug refractory supraventricular tachyarrhythmias (ST). Higher endothelin (ET) levels were observed during nonsustained STs. We aimed to examine the effect of sustained STs and the applied rate-control therapy on plasma ET levels. Twenty-two patients (12 men; mean age, 64.4 +/- 13.2 years; ejection fraction, 41.8 +/- 11.2%; New York Heart Association (NYHA) class I: 3 cases, NYHA II: 11 cases, and NYHA III: 8 cases) suffering of atrial fibrillation (n = 11), atrial flutter (n = 7), atrial paroxysmal tachycardia (n = 3), or sinus tachycardia (n = 1) were studied, having coronary artery disease (n = 8), dilative cardiomyopathy (n = 5), or no underlying diseases (n = 9). All groups went under catheter ablation (same protocol, duration: 35 +/- 10.3 mins; rate before ablation, 100-170/min in every case; after ablation, 70-80/min in Groups I and II and 70-90/min in Group III). A pacemaker (PM) was implanted 2 months before ablation in Group I (n = 9) and during ablation in Group II (n = 7). No PM was implanted in Group III (n = 6). A control group (n = 13; 7 men; mean age, 66.15 +/- 6.7 years) with sinus rhythm got a PM without ST and ablation. Blood samples were collected from the cubital vein immediately before (control), and 5 mins and 24 hrs after ablation. Plasma ET-1 and big ET-1 levels were measured after immunoprecipitation with Western blot analysis. There were no differences between plasma ET-1 levels in the ST groups and the control group (Groups I, II, and III vs. control group: 0.66 +/- 0.04 fmol/ml, 0.93 +/- 0.12 fmol/ml, and 0.68 +/- 0.05 fmol/ml vs. 0.50 +/- 0.05 fmol/ml, respectively; P < 0.05). Comparing the control, 5-min, and 24-hr samples, ET-1 levels decreased significantly after supraventricular tachycardia ablation in Groups I and III (control vs. Group I, 5 mins and 24 hrs: 0.66 +/- 0.04 fmol/ml vs. 0.50 +/- 0.04 fmol/ml and 0.29 +/- 0.05 fmol/ml; control vs. Group III, 24 hrs: 0.68 +/- 0.05 vs. 0.34 +/- 0.05 fmol/ml; P < 0.05). No plasma big ET-1 changes were measured in any of the groups. The rapid decrease of ET levels after catheter ablation suggests that a high ventricular rate can be a trigger of ET production. PM implantation procedure seems to interfere with the ET decrease in ST patients. |
9,585 | Implantable cardiac arrhythmia devices--part I: pacemakers. | Implantable cardiac devices have become firmly entrenched as important therapeutic tools for a variety of cardiac conditions. The first part of this two-part review will discuss the contemporary use and follow-up of pacemakers, while the second part will address the use of implantable cardioverter defibrillators and implantable loop recorders. Pacemakers are the only available treatment for symptomatic bradycardia not due to reversible causes. Large randomized studies have demonstrated a small but statistically significant reduction in atrial fibrillation associated with pacing modes that maintain atrioventricular synchrony. In contrast, pacing mode appears to have a less dramatic effect in patients with atrioventricular block. Cardiac resynchronization with specialized left ventricular leads has been shown to reduce symptoms and improve survival in patients with symptomatic heart failure, systolic dysfunction, and widened QRS complexes. For all patients, careful follow-up is necessary to ensure optimal therapeutic benefit of pacing systems. |
9,586 | [Short QT Syndromes]. | The inherited short QT syndrome (SQTS) is a novel, genetically determined arrhythmia that resembles the pathophysiological counterpart of congenital long QT syndrome (LQTS). Gain-of-function ion channel mutations in cardiac potassium channel genes are the currently known cause of SQTS and obvious genetic heterogeneity is evident from the few reported families. At present, three subforms are known, and probably, specific T-wave patterns make each subform recognizable. So far, only a few cases have been genetically unraveled. Treatment includes ICD implantation as the first-line option due to a high occurrence rate of ventricular fibrillation and repolarization-prolonging medications such as quinidine are under investigation. Whenever atrial and/or ventricular fibrillation occur in an idiopathic setting, SQTS has to be considered a potential cause. |
9,587 | [Morphology and function of the intrinsic cardiac nervous system]. | Access to the intrinsic cardiac autonomic nervous system can now be achieved via percutaneous catheter stimulation techniques. Thereby, cardiac functions like atrioventricular nodal conduction, sinus cycle length and ventricular inotropy can be dynamically regulated. The present article provides examples of this new technique in acute and chronic models but also first human applications. |
9,588 | Outcomes of in-hospital ventricular fibrillation in children. | Ventricular fibrillation and ventricular tachycardia are less common causes of cardiac arrest in children than in adults. These tachyarrhythmias can also begin during cardiopulmonary resuscitation (CPR), presumably as reperfusion arrhythmias. We determined whether the outcome is better for initial than for subsequent ventricular fibrillation or tachycardia.</AbstractText>All cardiac arrests in persons under 18 years of age were identified from a large, multicenter, in-hospital cardiac-arrest registry. The results from children with initial ventricular fibrillation or tachycardia, children in whom ventricular fibrillation or tachycardia developed during CPR, and children with no ventricular fibrillation or tachycardia were compared by chi-square and multivariable logistic-regression analysis.</AbstractText>Of 1005 index patients with in-hospital cardiac arrest, 272 (27 percent) had documented ventricular fibrillation or tachycardia during the arrest. In 104 patients (10 percent), ventricular fibrillation or tachycardia was the initial pulseless rhythm; in 149 patients (15 percent), it developed during the arrest. The time of initiation of ventricular fibrillation or tachycardia was not documented in 19 patients. Thirty-five percent of patients with initial ventricular fibrillation or tachycardia survived to hospital discharge, as compared with 11 percent of patients with subsequent ventricular fibrillation or tachycardia (odds ratio, 2.6; 95 percent confidence interval, 1.2 to 5.8). Twenty-seven percent of patients with no ventricular fibrillation or tachycardia survived to hospital discharge, as compared with 11 percent of patients with subsequent ventricular fibrillation or tachycardia (odds ratio, 3.8; 95 percent confidence interval, 1.8 to 7.6).</AbstractText>In pediatric patients with in-hospital cardiac arrests, survival outcomes were highest among patients in whom ventricular fibrillation or tachycardia was present initially than among those in whom it developed subsequently. The outcomes for patients with subsequent ventricular fibrillation or tachycardia were substantially worse than those for patients with asystole or pulseless electrical activity.</AbstractText>Copyright 2006 Massachusetts Medical Society.</CopyrightInformation> |
9,589 | Protective effects of Ping-Lv-Mixture (PLM), a medicinal formula on arrhythmias induced by myocardial ischemia-reperfusion. | Ping-Lv-Mixture (PLM) is a Chinese medicinal formula. The present study aimed to determine the effects of PLM on myocardial ischemia-reperfusion (MI/R) induced arrhythmias in rats. Arrhythmia model was established by occlusion of the left arterial descending coronary artery and thereafter reperfusion. A lead II electrocardiogram was monitored throughout the experiment. The results showed that pretreatment of PLM to MI/R rats significantly reduced the incidence and duration of ventricular tachycardia and ventricular fibrillation. On induction of MI/R, the activities of creatine kinase and lactate dehydrogenase were increased in vehicle group. PLM (0.04-1.00 g/kg) administration prevented the increase of these enzymes. Moreover, a significant increase of myocardium superoxide dismutase and decrease of malondialdehyde contents were observed in rats of PLM groups. On the other hand, the expressions of platelet activating factor (PAF) receptor mRNA was down-regulated in a dose-dependent manner in the PLM-treated groups by RT-PCR. Thus, it can be concluded that pretreatment with PLM inhibited lipid peroxidation in rats through suppressing the expression of PAF receptor, which may contribute to its preventive effect on myocardial ischemia-reperfusion induced arrhythmias. |
9,590 | Diastolic heart failure in the elderly and the potential role of aldosterone antagonists. | The overall incidence of heart failure increases with age, affecting up to 10% of people >65 years of age. Diastolic heart failure is also age-dependent, increasing from <15% in middle-aged patients to >40% in patients > or =70 years of age. Elderly patients usually have other co-morbid conditions such as hypertension, diabetes mellitus, coronary artery disease and atrial fibrillation that can adversely affect the diastolic properties of the heart. The clinical manifestations of diastolic heart failure are similar to those of systolic heart failure. In practice, the diagnosis is generally based on the finding of typical symptoms and signs of heart failure with preserved left ventricular ejection fraction and no valvular abnormalities on echocardiography. Altered ventricular relaxation and abnormal ventricular filling are the hallmarks of diastolic heart failure. Cardiac fibrosis and cellular disarray lead to the alterations in the diastolic properties of the heart. Diffuse foci of fibrosis in the myocardium have been reported with advancing age. Aldosterone has been shown to play a crucial role in the development of cardiac fibrosis via a direct effect on the mineralocorticoid receptors within the myocardium. Unlike the situation with treatment of systolic heart failure, few clinical trials are available to guide the management of patients with diastolic heart failure. In the absence of controlled clinical trials, patient management is based on control of the physiological factors (blood pressure, heart rate, blood volume and myocardial ischaemia) that are known to exert important effects on ventricular relaxation. Aldosterone antagonists inhibit the deposition of collagen matrix in the myocardium, thereby targeting the basic pathophysiological mechanism of diastolic dysfunction. Thus, they appear to represent a promising therapeutic approach for this condition. Currently, only small clinical trials supporting this therapy are available and large clinical trials evaluating long-term outcomes in diastolic dysfunction are therefore needed. |
9,591 | The effects of altering time delays of coupled pacing during acute atrial fibrillation. | Coupled pacing (CP), which consists of delivering a premature electrical stimulation to the heart after the effective refractory period of ventricular activation, is a novel method for controlling ventricular rate during atrial fibrillation (AF). It also has been established that CP improves pump function by enhancing external cardiac work and myocardial efficiency.</AbstractText>The purpose of the present study was to determine if two time delays for CP (short and long) would result in similar improvements in ventricular function.</AbstractText>In a canine model, we applied CP at two time delays (CP-S and CP-L) during two stages: sinus rhythm (SR) and acute AF. The cardiac responses to CP during SR served as the nontachycardic and nondepressed control. During both rhythms, we shortened the coupling interval until we obtained maximal contractility, designated CP-S. Next, we increased the delay until we started to see a measurable secondary contraction (left ventricular pressure development of approximately 20 mmHg). These longer delays were designated CP-L.</AbstractText>Our results showed that the ventricular rate of intrinsic activation (VRIA) remained decreased despite prolongation of the time delay of CP during both AF and SR. Also, both delays of CP increased left ventricular systolic pressure (LVSP) and dLVP/dt, which are indices of myocardial contractility. In contrast, CP increased external cardiac work only during AF. Prolonging this time delay did not markedly decrease the improvement in external cardiac work. Myocardial O(2) consumption (MVO(2)) did not significantly change as the result of CP during either SR or AF. Finally, myocardial efficiency improved during AF as the result of CP at both time delays.</AbstractText>In conclusion, shorter time delays for CP increased contractile strength during both SR and AF. However, extending the time delay of CP had minimal effects on diminishing the improved ventricular pump function and energetics that resulted from CP during AF. Thus, the maximal enhancement of myocardial contractility via CP-S was not needed to maintain the improved ventricular function during acute AF when CP is applied.</AbstractText> |
9,592 | Importance of spatiotemporal heterogeneity of cellular restitution in mechanism of arrhythmogenic discordant alternans. | Spatially discordant cellular alternans form a substrate for development of unidirectional block and ventricular fibrillation. However, the mechanisms responsible for discordant alternans remain poorly understood. Previous work suggests electrical restitution is critical to the development of alternans in single cells.</AbstractText>The purpose of this study was to investigate the hypothesis that spatial and temporal heterogeneities of restitution underlie the mechanism eliciting discordant alternans.</AbstractText>Steady-state pacing was used to elicit concordant cellular alternans in nine Langendorff-perfused guinea pig hearts. A single extrastimulus (S2) was applied every 51st beat following either the even or the odd beat of alternans. The cellular response to S2 was determined using optical mapping to generate action potential duration (APD) restitution curves from 256 ventricular sites for both the even and the odd beats.</AbstractText>Restitution kinetics were temporally heterogeneous during alternans, as restitution curves between the even and the odd beats differed significantly. Temporal heterogeneity was quantified by the average separation of restitution between the two curves, or Delta-restitution. Delta-Restitution was spatially heterogeneous and proportional to the amount of alternans at a given ventricular site. A computer simulation based on the experimental results showed the mechanism of discordant alternans was dependent on both spatial and temporal heterogeneities of restitution.</AbstractText>Both temporal and spatial heterogeneities of restitution exist during cellular alternans in the intact heart. Temporal heterogeneities of restitution, quantified by Delta-restitution, are proportional to the magnitude of cellular alternans. The combination of spatial and temporal heterogeneities of restitution may underlie the genesis of discordant alternans.</AbstractText> |
9,593 | Coronary sinus electrode does not reduce atrial defibrillation thresholds. | Atrial defibrillation can be achieved with a conventional dual-coil, active pectoral implantable cardioverter-defibrillator (ICD) lead system. Shocking vectors that incorporate an additional electrode in the CS have been used, but it is unclear if they improve atrial DFTs.</AbstractText>The objective of this prospective, randomized study was to determine if a coronary sinus (CS) electrode reduces atrial defibrillation thresholds (DFTs).</AbstractText>This was a prospective study of 36 patients undergoing initial ICD implant for standard indications. A defibrillation lead with superior vena cava (SVC) and right ventricular (RV) shocking coils was implanted in the RV. An active can emulator (Can) was placed in a pre-pectoral pocket. A lead with a 4 cm long shocking coil was placed in the CS. Atrial DFTs were determined in the following 3 shocking configurations in each patient, with the order of testing randomized: RV --> SVC + Can (Ventricular Triad), distal CS --> SVC + Can (Distal Atrial Triad), and proximal CS --> SVC + Can (Proximal Atrial Triad).</AbstractText>The Proximal and Distal Atrial Triad configurations were both associated with significant reductions in peak current (p < 0.01), but this effect was offset by significant increases in shock impedance (p < 0.01), resulting in no net change in the peak voltage or DFT energy in comparison to the Ventricular Triad configuration (Ventricular Triad: 4.9 +/- 6.6 J, Proximal Atrial Triad: 3.3 +/- 4.1J, Distal Atrial Triad: 4.4 +/- 6.7 J, p > 0.2).</AbstractText>Shocking vectors that incorporate a CS coil do not significantly improve atrial defibrillation efficacy. Since the Ventricular Triad shocking pathway provides reliable atrial and ventricular defibrillation, this configuration should be preferred for combined atrial and ventricular ICDs.</AbstractText> |
9,594 | Extramedullary hematopoiesis-related pleural effusion: the case of beta-thalassemia. | Thalassemia intermedia has a later clinical onset and a milder anemia than thalassemia major, characterized by high output state, left ventricle remodeling, and age-related pulmonary hypertension. Bone deformities, extramedullary hematopoiesis (EMH), and spleen and liver enlargement are the consequences of hypoxia and enhanced erythropoiesis. The EMH-related pleural effusion is rarely referred to in the literature of thalassemia.</AbstractText>We reviewed the thalassemia patients' medical records hospitalized for pleural effusion in our Department, within the last 6 years.</AbstractText>Eight (4 men) thalassemia intermedia patients admitted for symptomatic pleural effusion were identified. Common clinical findings on admission were dyspnea and apyrexia. Their mean hemoglobin level was 7.15 +/- 0.64 g/dL. Radiology revealed intrathoracic EMH and pleural effusion in all patients: exudative in seven patients and massive hemothorax in one. Cytologic fluid analysis was negative for malignancy. Fluid and serum cultures, antibodies, and stains were negative for viral, bacterial, and fungal infection. The hemothorax case was successfully treated with repeated aspirations, transfusions, and hydroxyurea. Although repeated thoracentesis and radiation could not control the effusions in the rest of the cases, pleurodesis was successful in 5 patients, without serious adverse events. Treatment was further accomplished with hydroxyurea. No relapses were observed in the mean 30 month follow-up period.</AbstractText>Afebrile, EMH-related pleuritis represents a potentially life-threatening complication in thalassemia. Therapy should be individualized and treatment is emerging. Pleurodesis seems to be an effective and safe therapeutic option for exudative effusions, while transfusion-chelation therapy combined with hydroxyurea may be helpful in suppressing increased erythropoiesis.</AbstractText> |
9,595 | Non-compaction cardiomyopathy in an adult with hereditary spherocytosis. | A 23-year old male (199 cm, 88 kg) presented muscular weakness due to skeletal myopathy and symptoms of heart failure NYHA functional class II. Total creatine kinase was increased up to 830 U/l, but troponin was negative. Prior episodes of intermittent atrial fibrillation were reported and 6 years ago splenectomy was performed due to hereditary spherocytosis. Cardiac magnetic resonance imaging revealed the spongy appearance of non-compacted left ventricular myocardium. This impaired fetal morphogenesis occurred predominantly in the apical to midventricular anterior, lateral and inferior segments. Non-compaction cardiomyopathy was initially described in paediatric patients. Occasional associations with other congenital disorders are known, e.g., Barth syndrome, which is an X-linked disease characterized by cardio-skeletal myopathy of variable severity and neutropenia. To our knowledge, combined occurrence of non-compaction cardiomyopathy, skeletal myopathy and hereditary spherocytosis has not previously been reported. |
9,596 | Tertiapin, a selective IKACh blocker, terminates atrial fibrillation with selective atrial effective refractory period prolongation. | It is well known that vagal nerve tone plays a crucial role in atrial fibrillation (AF). Acetylcholine-activated potassium current (IKACh) mediates much of the cardiac response to vagal nerve stimulation (VNS), but the contribution of IKACh to AF remains unknown. We investigated the role of the IKACh channel in canine AF models using tertiapin, a selective IKACh blocker. Tertiapin (4-41 nmol kg(-1), i.v.) terminated AF in the canine VNS-induced and aconitine-induced AF models. The muscarinic M-receptor antagonist AF-DX-116 terminated AF in these models, but the adenosine receptor antagonist DPCPX had no effect. Thus it is likely that IKACh activation via the M-receptor has a crucial role in both models. Tertiapin (12 nmol kg(-1), i.v.) preferentially prolonged the atrial effective refractory period (ERP) but not the ventricular ERP under the VNS condition. This peptide (4-41 nmol kg(-1), i.v.) did not affect PQ, QRS and corrected QT intervals in isoflurane-anaesthetised dogs. These results suggest that a selective IKACh blocker is effective in canine AF models without affecting ventricular repolarisation, and might be useful for the treatment of patients with AF. |
9,597 | Underlying cardiomyopathy in patients with ST-segment elevation in the right precordial leads. | Ventricular fibrillation (VF) and sudden death (SD) may occur in patients with ST-segment elevation in the right precordial leads. The mechanism of such events is unclear, so the aim of the present study was to assess whether there is an underlying morphological or pathological abnormality in these patients.</AbstractText>Fourteen consecutive patients (44+/-10 years old, all male) with ST-segment elevation of more than 2 mm in the right precordial leads underwent a cardiac evaluation, including right ventriculography and endomyocardial biopsy. The ST-segment changes after the administration of sodium-channel blockers were also evaluated. Two patients survived documented VF, 11 patients had chest pain or tightness, and another patient had a history of syncope. Only 1 patient had a family history of premature SD. The coronary angiograms were normal in all the patients. VF was induced in 5 patients (36%). Wall motion abnormalities of the right ventricle were detected in 4 patients (29%) and endomyocardial biopsy revealed features of cardiomyopathy in 7 patients (50%). In total, 9 (64%) of 14 patients exhibited wall motion abnormalities and/or pathologic findings.</AbstractText>Underlying cardiomyopathy was present in more than half of the present patients with ST-segment elevation in the right precordial leads.</AbstractText> |
9,598 | Clinical evaluation of adverse effects during bepridil administration for atrial fibrillation and flutter. | Bepridil hydrochloride (Bpd) has attracted attention as an effective drug for atrial fibrillation (AF) and atrial flutter (AFL). However, serious adverse effects, including torsade de pointes (Tdp), have been reported.</AbstractText>Adverse effects of Bpd requiring discontinuation of treatment were evaluated. Bpd was administered to 459 patients (361 males, 63+/-12 years old) comprising 378 AF and 81 AFL cases. Mean left ventricular ejection fraction and atrial dimension (LAD) were 66+/-11% and 40+/-6 mm, respectively. Adverse effects were observed in 19 patients (4%) during an average follow-up of 20 months. There was marked QT prolongation greater than 0.55 s in 13 patients, bradycardia less than 40 beats/min in 6 patients, dizziness and general fatigue in 1 patient each. In 4 of 13 patients with QT prolongation, Tdp occurred. The major triggering factors of Tdp were hypokalemia and sudden decrease in heart rate. There were no differences in the clinical backgrounds of the patients with and without Tdp other than LAD and age, which were larger and older in the patients with Tdp.</AbstractText>Careful observation of serum potassium concentration and the ECG should always be done during Bpd administration, particularly in elderly patients.</AbstractText> |
9,599 | A knowledge-based method for reducing attenuation artefacts caused by cardiac appliances in myocardial PET/CT. | Attenuation artefacts due to implanted cardiac defibrillator leads have previously been shown to adversely impact cardiac PET/CT imaging. In this study, the severity of the problem is characterized, and an image-based method is described which reduces the resulting artefact in PET. Automatic implantable cardioverter defibrillator (AICD) leads cause a moving-metal artefact in the CT sections from which the PET attenuation correction factors (ACFs) are derived. Fluoroscopic cine images were measured to demonstrate that the defibrillator's highly attenuating distal shocking coil moves rhythmically across distances on the order of 1 cm. Rhythmic motion of this magnitude was created in a phantom with a moving defibrillator lead. A CT study of the phantom showed that the artefact contained regions of incorrect, very high CT values and adjacent regions of incorrect, very low CT values. The study also showed that motion made the artefact more severe. A knowledge-based metal artefact reduction method (MAR) is described that reduces the magnitude of the error in the CT images, without use of the corrupted sinograms. The method modifies the corrupted image through a sequence of artefact detection procedures, morphological operations, adjustments of CT values and three-dimensional filtering. The method treats bone the same as metal. The artefact reduction method is shown to run in a few seconds, and is validated by applying it to a series of phantom studies in which reconstructed PET tracer distribution values are wrong by as much as 60% in regions near the CT artefact when MAR is not applied, but the errors are reduced to about 10% of expected values when MAR is applied. MAR changes PET image values by a few per cent in regions not close to the artefact. The changes can be larger in the vicinity of bone. In patient studies, the PET reconstruction without MAR sometimes results in anomalously high values in the infero-septal wall. Clinical performance of MAR is assessed by two physicians' inspection of images generated in 30 patients with and without MAR. Noticeable image differences are judged in 14 of 28 (50%) observations with AICD leads, and significant clinical impact is judged in 2 of 28 (7%) of those observations. A polar map analysis shows significant differences in 10 of 14 (71%) studies with AICD leads, and 0 of 16 (0%) studies without AICD leads. These results show that the MAR method is successful in reducing the magnitude of the metal artefact without incorrectly altering cases without metal artefact. In spite of profound changes to the CT image from the moving metal, the PET ACF in that study was changed by no more than 20%. |
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