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14,000 | Intracardiac J-point elevation before the onset of polymorphic ventricular tachycardia and ventricular fibrillation in patients with an implantable cardioverter-defibrillator. | The clinical importance of the J-point elevation on electrocardiogram is controversial.</AbstractText>To study intracardiac J-point amplitude before ventricular arrhythmia.</AbstractText>Baseline 12-lead electrocardiogram and far-field right ventricular intracardiac implantable cardioverter-defibrillator electrograms were recorded at rest in 494 patients (mean age 60.4 ± 13.1 years; 360 [72.9%] men) with structural heart disease (278 [56.3%] ischemic cardiomyopathy) who received primary (463 [93.9%] patients) or secondary prevention implantable cardioverter-defibrillator. Ten-second intracardiac far-field electrograms before the onset of arrhythmia were compared with the baseline. The J-point amplitude was measured on the baseline 12-lead surface electrocardiogram and the intracardiac far-field electrogram. The relative J-point amplitude was calculated as the ratio of J-point amplitude to peak-to-peak R-wave.</AbstractText>The paired t test showed that the relative intracardiac J-point amplitude was significantly higher before polymorphic ventricular tachycardia/ventricular fibrillation (VF) onset (0.28 ± 0.08 vs -0.19 ± 0.39; P = .012) than at baseline. In a mixed-effects logistic regression model, adjusted for multiple episodes per patient, each 10% increase in relative J-point amplitude increased the odds of having ventricular tachycardia/VF by 13% (odds ratio 1.13 [95% confidence interval 1.07-1.19]; P < .0001) and increased the odds of having polymorphic ventricular tachycardia/VF by 27% (odds ratio 1.27 [95% confidence interval 1.11-1.46]; P = .001).</AbstractText>The relative intracardiac J-point amplitude is augmented immediately before the onset of polymorphic ventricular tachycardia/VF in patients with structural heart disease.</AbstractText>Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,001 | Myocardial fibrosis severity on cardiac magnetic resonance imaging predicts sustained arrhythmic events in hypertrophic cardiomyopathy. | The purpose of our study was to correlate the incidence of adequate implantable cardioverter-defibrillator (ICD) interventions in hypertrophic cardiomyopathy (HCM) patients with risk markers (RMs) for sudden cardiac death (SCD) plus myocardial fibrosis as detected by late gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) imaging.</AbstractText>In all, 87 patients with HCM underwent LGE-CMR imaging prior to ICD implantation, performed for secondary (n = 2; 2%) or primary SCD prophylaxis (n = 85; 98%). Fibrosis was graded with a 17-segment left ventricular model (0 = absent, 1 = point-shaped, 2 = limited to 1 left ventricular segment, 3 = involving ≥ 2 segments). During follow-up, ICD memories were read out by a physician blinded to the individual patient data.</AbstractText>The number of RMs per patient was 1.9 ± 0.8. Myocardial fibrosis was present in 78 patients (90%); 26 (30%) had a fibrosis score of 3. During follow-up (3.5 ± 2.6 [range, 0.2-11.4 years]), 15 patients had 50 appropriate ICD interventions. Episodes of atrial fibrillation were found in 28 patients. Fibrosis severity correlated with occurrence of ventricular tachycardia (Cramér's V, or φc = 0.4, P < 0.001) and atrial fibrillation (φc = 0.6, P < 0.001). On multivariate regression analysis, an independent association between myocardial fibrosis (ß = 0.6, P < 0.01) and sustained ventricular tachycardia was found.</AbstractText>In HCM patients treated with ICD implantation because of a high SCD risk by traditional RM assessment, a high rate of arrhythmic events was observed during long-term follow-up. In a cohort of patients with clinical markers for high risk of SCD, severity of myocardial fibrosis as detected by an easy LGE-CMR scoring system was associated with future arrhythmic events and appropriate ICD therapies.</AbstractText>Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,002 | Repolarization syndromes. | Repolarization syndromes, including early repolarization, Brugada, and short and long QT, have been implicated increasingly as causes of sudden cardiac death (SCD) despite no obvious mechanical cardiac abnormalities. So-called idiopathic ventricular fibrillation is now often reassigned to one of the aforementioned entities. Underlying causes are diverse; genetic mutation has been proven in many but not all cases. Although high-risk individuals generally can be identified, most of the potential victim pool is still unknown and cannot be discovered at this time. Awareness of these entities' existence, knowledge of family history, and 12-lead electrocardiography are the initial steps toward preventing SCD in this population. Underlying mechanisms for ventricular tachycardia/fibrillation in such individuals include phase 2 reentry, early after depolarization, and vortex reentry. For the time-being, although most forms of long QT syndrome can be treated with β-blockers, an implantable cardioverter-defibrillator remains the only definitive therapy for the prevention of arrhythmic death among high-risk populations. |
14,003 | NADPH oxidases in heart failure: poachers or gamekeepers? | Oxidative stress is involved in the pathogenesis of heart failure but clinical antioxidant trials have been unsuccessful. This may be because effects of reactive oxygen species (ROS) depend upon their source, location, and concentration. Nicotinamide adenine dinucleotide phosphate oxidase (Nox) proteins generate ROS in a highly regulated fashion and modulate several components of the heart failure phenotype.</AbstractText>Two Nox isoforms, Nox2 and Nox4, are expressed in the heart. Studies using gene-modified mice deficient in Nox2 activity indicate that Nox2 activation contributes to angiotensin II-induced cardiomyocyte hypertrophy, atrial fibrillation, and the development of interstitial fibrosis but may also positively modulate physiological excitation-contraction coupling. Nox2 contributes to myocyte death under stress situations and plays important roles in postmyocardial infarction remodeling, in part by modulating matrix metalloprotease activity. In contrast to Nox2, Nox4 is constitutively active at a low level and induces protective effects in the heart under chronic stress, for example, by maintaining myocardial capillary density. However, high levels of Nox4 could have detrimental effects.</AbstractText>The effects of Nox proteins during the development of heart failure likely depend upon the isoform, activation level, and cellular distribution, and may include beneficial as well as detrimental effects. More needs to be learnt about the precise regulation of abundance and biochemical activity of these proteins in the heart as well as the downstream signaling pathways that they regulate.</AbstractText>The development of specific approaches to target individual Nox isoforms and/or specific cell types may be important for the achievement of therapeutic efficacy in heart failure.</AbstractText> |
14,004 | Pregnancy outcome and management of women with an implantable cardioverter defibrillator: a single centre experience. | With improved survival of patients with congenital and inherited heart disease, there is now a younger cohort of patients with an implantable cardioverter defibrillator (ICD) for the prevention and treatment of ventricular dysrrhythmias. Young women with such disorders often wish to embark on pregnancy, but pregnancy outcome data for this group is sparse. We therefore evaluated pregnancy outcome in patients with heart disease and an ICD in situ.</AbstractText>A retrospective analysis was performed on all women with an ICD in situ, who had pregnancy care provided by the specialist maternal cardiology service at University College London Hospitals. Data for 19 pregnancies in 14 women were collected. The underlying cardiac diagnoses were congenital heart disease (one), familial hypertrophic cardiomyopathy (eight), familial dilated cardiomyopathy (one), inherited long QT syndrome (one), and idiopathic cardiac arrest (one). Three women had moderate impairment of the left ventricular systolic function (ejection fraction <45%), in the remainder it was normal. Nine ICD implants were for primary prevention of sudden cardiac death (64%) and five for secondary prevention (36%). Of the 19 pregnancies, 18 continued beyond 24 weeks gestation with 18 live births. In eight pregnancies there were medical or device-related complications (42.9%) as follows: arrhythmias (four) (21.1%), heart failure (two) (9.1%), ICD shocks (one) (5.3%), atrial lead fracture (one) (5.3%), and lead-related thrombus (one) (5.3%). There were no inappropriate device shocks or therapies.</AbstractText>Women with heart disease and an ICD implant can have a good outcome during pregnancy but medical and device complications are not uncommon.</AbstractText> |
14,005 | [Prolonged hypothermia in refractory intracranial hypertension. Report of one case]. | The use of hypothermia after cardiac arrest caused by ventricular fibrillation is a standard clinical practice, however its use for neuroprotection has been extended to other conditions. We report a 23-year-old male with intracranial hypertension secondary to a parenchymal hematoma associated to acute hydrocephalus. An arterial malformation was found and embolized. Due to persistent intracranial hypertension, moderate hypothermia with a target temperature of 33°C was started. After 12 hours of hypothermia, intracranial pressure was controlled. After 13 days of hypothermia a definitive control of intracranial pressure was achieved. The patient was discharged 40 days after admission, remains with a mild hemiparesia and is reassuming his university studies. |
14,006 | Andersen-Tawil syndrome associated with aborted sudden cardiac death: atrial pacing was effective for ventricular arrhythmias. | A 37-year-old Japanese woman experienced aborted sudden cardiac death from ventricular fibrillation and was diagnosed with Andersen-Tawil syndrome by genetic analysis that revealed 2 mutations in the KCNJ2 gene. Although she received an implantation of implantable cardioverter defibrillator and beta-blocker therapy, the frequency of premature ventricular contraction and bidirectional ventricular tachycardia did not decrease. Her ventricular arrhythmias increased after a full stomach test and a neostigmine provocation test, and reduced after cibenzoline administration, which indicates the relation with vagal tone. Moreover, increasing the pacing rate significantly decreased them. These findings indicate that the arrhythmia was bradycardia-dependent in this case. |
14,007 | Renal infarction as a presentation of Austrian syndrome: thromboembolic phenomenon of pneumococcal endocarditis. | A 52-year-old unvaccinated and splenectomized man presented with fever, altered sensorium, bilateral flank pain and chest discomfort accompanied with paroxysmal atrial fibrillation with a rapid ventricular response. An abdominal computed tomography scan was performed, which revealed a right renal infarct and splenosis. Transthoracic echocardiography was performed, which demonstrated an echodense structure on the mitral valve with mitral regurgitation and a vegetation on the aortic valve with aortic regurgitation. Subsequently, he was found to have pneumococcal infective endocarditis, pneumococcal pneumonia and bacterial meningitis, namely Austrian syndrome. He underwent an early aortic valve and mitral valve repair but still had a poor clinical outcome. Renal infarction has a mortality of approximately 13.2%, which is strongly influenced by the underlying diseases and infectious complications. Medical and surgical treatment initiated in a timely manner is often inadequate. The authors report the first case of Austrian syndrome presenting with renal infarction as a clue to an embolic event associated with infective endocarditis in this study. |
14,008 | Cation interdependency in acute stressor states. | Acute stressor states are inextricably linked to neurohormonal activation which includes the adrenergic nervous system. Consequent elevations in circulating epinephrine and norepinephrine unmask an interdependency that exists between K+, Mg2+ and Ca2+. Catecholamines, for example, regulate the large number of Mg2+-dependent Na/K ATPase pumps present in skeletal muscle. A hyperadrenergic state accounts for a sudden translocation of K+ into muscle and rapid appearance of hypokalemia. In the myocardium, catecholamines promote Mg2+ efflux from cardiomyocytes, whereas intracellular Ca2+ influx and overloading account for the induction of oxidative stress and necrosis of these cells with leakage of their contents, including troponins. Accordingly, acute stressor states can be accompanied by nonischemic elevations in serum troponins, together with the concordant appearance of hypokalemia, hypomagnesemia and ionized hypocalcemia, causing a delay in myocardial repolarization and electrocardiographic QTc prolongation raising the propensity for arrhythmias, including atrial fibrillation and polymorphic ventricular tachycardia. In this review, we focus on the interdependency between K+, Mg2+ and Ca2+ which are clinically relevant to acute stressor states. |
14,009 | Brugada syndrome masked by ibutilide treatment in a patient with atrial flutter. | We present a case of Brugada syndrome in a young patient whose typical ECG pattern was 'masked' after ibutilide was administered for atrial flutter cardioversion. Ibutilide, a class III antiarrhythmic agent used for the treatment of atrial fibrillation and flutter, prolongs the action potential duration plateau phase by augmenting the slow component of the inward Na(+) current and by blocking the rapid component of the delayed rectifier potassium current. Insights into the pathophysiology of Brugada syndrome and this first-reported action of ibutilide are supplied, providing a plausible scientific basis for the masking effect of ibutilide. Furthermore, issues concerning the safety of ibutilide administration in patients with Brugada syndrome along with the importance of programmed ventricular stimulation and especially short-long-short sequence protocol in inducing ventricular fibrillation in these patients are also discussed. |
14,010 | Role of imaging in ablation therapy of ventricular arrhythmias. Focus on cardiac magnetic resonance imaging. | Cardiac magnetic resonance imaging (MRI) has a central role in the management of patients with ventricular arrhythmias. Cardiac MRIs help to identify patients with risk for life-threatening arrhythmias. Delayed enhancement identifies scar tissue within the heart. Because scar harbors the arrhythmic substrate in patients with structural heart disease, areas of delayed enhancement can be targeted in order to eliminate ventricular arrhythmias with catheter ablation procedures. In this article, we will discuss the role of MRI in diagnosing different forms of non-ischemic cardiomyopathy and its role in risk stratification. Furthermore, we will discuss the role of MRI in imaging of the arrhythmogenic substrate in patients with structural heart disease. |
14,011 | Prospective risk stratification of sudden cardiac death in Marfan's syndrome. | Marfan syndrome (MFS) is a variable, autosomal-dominant disorder of the connective tissue. In MFS serious ventricular arrhythmias and sudden cardiac death (SCD) can occur. The aim of this prospective study was to reveal underlying risk factors and to prospectively investigate the association between MFS and SCD in a long-term follow-up.</AbstractText>77 patients with MFS were included. At baseline serum N-terminal pro-brain natriuretic peptide (NT-proBNP), transthoracic echocardiogram, 12-lead resting ECG, signal-averaged ECG (SAECG) and a 24-h Holter ECG with time- and frequency domain analyses were performed. The primary composite endpoint was defined as SCD, ventricular tachycardia (VT), ventricular fibrillation (VF) or arrhythmogenic syncope.</AbstractText>The median follow-up (FU) time was 868 days. Among all risk stratification parameters, NT-proBNP remained the exclusive predictor (hazard ratio [HR]: 2.34, 95% confidence interval [CI]: 1.1 to 4.62, p=0.01) for the composite endpoint. With an optimal cut-off point at 214.3 pg/ml NT-proBNP predicted the composite primary endpoint accurately (AUC 0.936, p=0.00046, sensitivity 100%, specificity 79.0%). During FU, seven patients of Group 2 (NT-proBNP ≥ 214.3 pg/ml) reached the composite endpoint and 2 of these patients died due to SCD. In five patients, sustained VT was documented. All patients with a NT-proBNP<214.3 pg/ml (Group 1) experienced no events. Group 2 patients had a significantly higher risk of experiencing the composite endpoint (logrank-test, p<0.001).</AbstractText>In contrast to non-invasive electrocardiographic parameter, NT-proBNP independently predicts adverse arrhythmogenic events in patients with MFS.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,012 | Higher incidence of atrial fibrillation in the metabolic syndrome: a Hispanic population study. | The metabolic syndrome is probably one of the main medical problems in developing countries. Purpose of this investigation was to study the metabolic syndrome at the Puerto Rico and Caribbean Cardiovascular Center with emphasis on the cardiovascular complications.</AbstractText><AbstractText Label="MATERIALS/METHODS" NlmCategory="METHODS">The medical charts in the last six years of the metabolic syndrome were evaluated at the PRCCC.</AbstractText>One Hundred and Seventy-Three patients met the consensus criteria of the metabolic syndrome. The mean age was 60 years. Fifty-seven percent were males and 42% females. The mean body mass was 30 kg/m. The ejection fraction was subnormal (49 +/- 8%). The end systolic dimension of the left atrium was increased (45 +/- 10mm) when compared to normal. The incidence of atrial fibrillation was 16%.</AbstractText>The metabolic syndrome in this sub-group of Hispanics, showed a higher incidence of atrial fibrillation without ventricular tachycardia. This is probably related to abnormal left ventricular and atrial function.</AbstractText> |
14,013 | Recurrent ventricular fibrillation related to hypokalemia in early repolarization syndrome. | We describe a case of early repolarization syndrome in which augmented J waves were documented during an electrical storm associated with hypokalemia. The patient was referred to our hospital for therapy to treat recurrent ventricular fibrillation (VF). The 12-lead electrocardiogram showed giant J waves associated with hypokalemia during multiple episodes of VF. Although antiarrhythmic agents or deep sedation were not effective for the VF, an intravenous supplementation of potassium completely suppressed the VF with a reduction in the J-wave amplitude. Our report discusses the possible relationship between hypokalemia and VF in early repolarization syndrome. |
14,014 | Persistent atrial fibrillation is associated with inability to recover atrial contractility after MAZE IV surgery in rheumatic disease. | MAZE IV surgery is effective in restoring sinus rhythm (SR) and atrial contraction (AC) in patients with nonrheumatic persistent atrial fibrillation (AF). However, there is less information on its effectiveness to restore AC in patients with rheumatic disease.</AbstractText>To assess the effectiveness of the MAZE IV surgery in restoring AC in patients with rheumatic disease and long persistent AF.</AbstractText>Prospective, consecutive study in patients who underwent cardiovascular surgery and had long persistent AF in whom MAZE IV surgery was performed. The presence of AC was assessed by lateral mitral annulus tissue Doppler.</AbstractText>A total of 75 patients were included. Mean age 60 years (±11.7); 27 men (36%). AF duration was 63 months (±34.1). Primary indication for surgery: rheumatic mitral stenosis 67 patients and mitral insufficiency eight patients. Mean left ventricular ejection fraction (LVEF) was 51.8% (±12.1) and mean left atrial area was 37 cm(2) (±10.3). After a mean follow-up of 28 months (±9.3), 69 patients remained alive and 59 were in SR. AC was detected in 37.3% (Group A) and absent in 62.7% (Group B). The mean difference between groups was the high prevalence of AF longer than 5 years in group B (P = 0.000001). There were no differences related to left atrial size, LVEF, and age.</AbstractText>In patients with rheumatic disease, the absence of correlation between SR recovery and AC recovery post MAZE IV surgery is significant. A history of long persistent AF lasting more than 5 years was a strong predictor for the absence of AC.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,015 | Predictors of permanent pacemaker implantation after Medtronic CoreValve bioprosthesis implantation. | High-grade conduction disturbances requiring permanent pacemaker (PPM) implantation occur in up to 40% of patients following transcatheter aortic valve implantation (TAVI). The aim of this study was to identify pre-operative risk factors for PPM implantation after TAVI with the Medtronic CoreValve prosthesis (CVP).</AbstractText>We retrospectively analysed 109 patients following transfemoral CVP implantation performed between 2008 and 2009 at the Leipzig Heart Center. Patients who had indwelling PPM at the time of TAVI (n = 21) were excluded, leaving 88 patients for analysis. Mean age was 80.3 ± 6.6 years and logistic EuroScore predicted risk of mortality was 23.3 ± 12.1%. A total of 32 patients (36%) underwent PPM implantation post-TAVI during the same hospital admission. A total of 27/88 (31%) had evidence of pre-operative abnormal conduction, including first degree AV block and left bundle brunch block. Statistically significant risk factors for the need for post-operative PPM were patient age >75 years [P = 0.02, odds ratio (OR) 4.6], pre-operative heart rate <65 beats per minute (b.p.m.; P = 0.04, OR 2.9), CVP oversizing >4 mm (P = 0.03, OR 2.8), CVP prosthesis >26 mm (OR 2.2), atrial fibrillation (P = 0.001, OR 5.2), and ventricular rate <65 b.p.m. at the first post-operative day (P = 0.137, OR 6.0).</AbstractText>PPM implantation occurs frequently after transfemoral TAVI with the CVP. Older age, chronic atrial fibrillation, pre-operative bradycardia, and larger or significantly oversized prostheses were independent risk factors for PPM implantation following TAVI with the CVP.</AbstractText> |
14,016 | Association of early repolarization and sudden cardiac death during an acute coronary event. | Electrocardiographic early repolarization (ER) pattern has been previously associated with arrhythmic mortality and with an increased risk of ventricular fibrillation. We hypothesized that there is an association between ER and sudden cardiac death (SCD) during an acute coronary event.</AbstractText>The present study included 432 consecutive victims of SCD because of acute coronary event and 532 survivors of such an event, in whom 12-lead ECGs recorded before and unrelated to the event could be evaluated. SCDs were verified by medicolegal autopsy to be because of acute coronary event. ER was defined as an elevation of the QRS-ST junction in at least 2 inferior or lateral leads, manifested as QRS notching or slurring. The prevalence of ER pattern ≥0.1 mV was more common in cases (62/432; 14.4%) than controls (42/532; 7.9%) (P=0.001). The victims of SCD were younger, were more commonly men and smokers, had lower body mass index, had elevated heart rate, had prolonged QRS complex, and had lower prevalence of history of prior cardiovascular disease than controls. After adjustments for baseline differences, the odds ratio for J waves without ST-segment elevation in the SCD group was 2.15 (95% CI, 1.20-3.85; P=0.01).</AbstractText>Higher prevalence of ER in a standard 12-lead ECG in victims of SCD than in survivors of an acute coronary event suggests that the presence of ER increases the vulnerability to fatal arrhythmia during acute myocardial ischemia and provides a plausible mechanistic link between this ECG pattern and higher arrhythmic mortality of middle-aged/elderly subjects.</AbstractText> |
14,017 | Electroporation induced by internal defibrillation shock with and without recovery in intact rabbit hearts. | Defibrillation shocks from implantable cardioverter defibrillators can be lifesaving but can also damage cardiac tissues via electroporation. This study characterizes the spatial distribution and extent of defibrillation shock-induced electroporation with and without a 45-min postshock period for cell membranes to recover. Langendorff-perfused rabbit hearts (n = 31) with and without a chronic left ventricular (LV) myocardial infarction (MI) were studied. Mean defibrillation threshold (DFT) was determined to be 161.4 ± 17.1 V and 1.65 ± 0.44 J in MI hearts for internally delivered 8-ms monophasic truncated exponential (MTE) shocks during sustained ventricular fibrillation (>20 s, SVF). A single 300-V MTE shock (twice determined DFT voltage) was used to terminate SVF. Shock-induced electroporation was assessed by propidium iodide (PI) uptake. Ventricular PI staining was quantified by fluorescent imaging. Histological analysis was performed using Masson's Trichrome staining. Results showed PI staining concentrated near the shock electrode in all hearts. Without recovery, PI staining was similar between normal and MI groups around the shock electrode and over the whole ventricles. However, MI hearts had greater total PI uptake in anterior (P < 0.01) and posterior (P < 0.01) LV epicardial regions. Postrecovery, PI staining was reduced substantially, but residual staining remained significant with similar spacial distributions. PI staining under SVF was similar to previously studied paced hearts. In conclusion, electroporation was spatially correlated with the active region of the shock electrode. Additional electroporation occurred in the LV epicardium of MI hearts, in the infarct border zone. Recovery of membrane integrity postelectroporation is likely a prolonged process. Short periods of SVF did not affect electroporation injury. |
14,018 | Induction of ventricular tachycardia with the fourth extrastimulus and its relationship to risk of arrhythmic events in patients with post-myocardial infarct left ventricular dysfunction. | The prognostic significance of ventricular tachycardia (VT) induced by three extrastimuli (ES) is similar to that of VT induced by one or two ES in patients with coronary disease and abnormal left ventricular (LV) function. The significance of VT inducible with four ES is unclear. To examine the prognostic significance of VT inducible with the fourth ES in patients with post-myocardial infarct (MI) LV dysfunction.</AbstractText>Consecutive patients (n= 432) with post-MI LV ejection fraction ≤40% underwent electrophysiological (EP) studies for risk stratification. Inducible VT ≥ 200 ms cycle length (CL) with one to four ES was considered inducible. The primary endpoint of arrhythmia (sudden death or spontaneous VT/ventricular fibrillation) was compared among patients with VT inducible with less than or equal to two, three, and four ES. The incidence of inducible VT was 37.9% (n= 164). In patients with inducible VT, inducibility was with less than or equal to two, three, and four ES in 24% (n= 39), 46% (n= 75), and 30% (n= 50). Compared to VT induced with less than or equal to three ES, VT induced with the fourth ES was of shorter CL (218 vs. 256 ms, P = 0.01) and more likely to be haemodynamically unstable requiring cardioversion (77 vs. 55%, P = 0.05). After 3 years the primary endpoint occurred in 28 ± 8, 28 ± 6, and 18 ± 6% in patients with VT induced with less than or equal to two, three, and four ES, respectively (P= 0.31) and in 5 ± 2% of EP-negative patients (P< 0.01).</AbstractText>In patients with post-MI LV dysfunction, VT can be induced in a significant proportion of patients with the fourth ES. These patients are at comparable risk of arrhythmia to patients with inducible VT with less than or equal to three ES.</AbstractText> |
14,019 | Decreased milk drinking causing flecainide toxicity in an older child. | Flecainide is a class IC antiarrhythmic agent, used frequently in all age groups for the treatment of tachyarrhythmias. Flecainide blocks the voltage-gated sodium channel in the myocardium, leading to prolongation of depolarisation resulting in slowed conduction velocity. Within a paediatric population, flecainide is indicated primarily for supraventricular tachycardia resulting from atrioventricular nodal re-entry and accessory pathway mediated re-entry. It can be considered for use in patients with atrial tachycardia, fascicular ventricular tachycardia, benign right ventricular outflow tract tachycardia and paroxysmal atrial fibrillation. It is well documented to cause paradoxical proarryhthmia in children, with evidence that milk can reduce absorption in infants. The authors present the case of an older child whose flecainide levels were persistently subtherapeutic until he reduced his milk intake. At this time he developed symptoms of severe flecainide toxicity associated with increased levels. |
14,020 | Effect of cardiopulmonary resuscitation on restoration of myocardial ATP in prolonged ventricular fibrillation. | There has been controversy over whether a short period of cardiopulmonary resuscitation (CPR) prior to defibrillation improves survival in patients who experienced a sudden cardiac arrest. However, there have been no reports about whether CPR restores the myocardial energy source during prolonged ventricular fibrillation (VF). The aim of this study is to investigate the effect of CPR in restoring myocardial high energy phosphates during prolonged VF.</AbstractText>Seventy-two adult male Sprague-Dawley rats were used in this study. Baseline adenosine triphosphate (ATP) and adenosine diphosphate (ADP) prior to induction of VF were measured in nine rats, the No-VF group. Sixty-three rats were subjected to 4 min of untreated VF. Animals were then randomized into two groups: No-CPR (n=37) and CPR (n=26). In the No-CPR group, ATPs and ADPs were measured at 4 min (No-CPR4), 6 min (No-CPR6), 8 min (No-CPR8) or 10 min (No-CPR10) after the induction of VF. The CPR group received 2 min (CPR2), 4 min (CPR4) or 6 min (CPR6) of mechanical chest compressions before ATP was measured. Myocardial ATP (nmol/mg protein) was decreased as VF duration was prolonged (No-VF: 5.49±1.71, No-CPR4: 4.27±1.58, No-CPR6: 4.13±1.31, No-CPR8: 3.77±1.42, No-CPR10: 3.52±0.90, p<0.05 between each of No-CPRs vs. No-VF). Two minutes of CPR restored myocardial ATP to the level of No-VF group (5.27±1.67 nmol/mg protein in CPR2, p>0.05 vs. No-VF group). However, myocardial ATP (nmol/mg protein) decreased if the duration of CPR was longer than 2 min (CPR4: 3.77±1.05, CPR6: 3.49±1.08, p<0.05 between CPR4 and CPR6 vs. No-VF).</AbstractText>CPR for 2 min helps to maintain myocardial ATP after prolonged VF.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,021 | Electrophysiological and hemodynamic characteristics associated with obesity in patients with atrial fibrillation. | The authors sought to characterize the left atrial (LA) and pulmonary vein (PV) electrophysiological and hemodynamic features in obese patients with atrial fibrillation (AF).</AbstractText>Obesity is associated with increased risk for AF.</AbstractText>A total of 63 consecutive patients with AF who had normal left ventricular (LV) ejection fraction and who underwent catheter ablation were studied. Atrial and PV electrophysiological studies were performed at the time of ablation with hemodynamic assessment by cardiac catheterization, and LA/LV structure and function by echocardiography. Patients were compared on the basis of body mass index (BMI): <25 kg/m(2) (n = 19) and BMI ≥30 kg/m(2) (n = 44).</AbstractText>At a 600-ms pacing cycle length, obese patients had shorter effective refractory period (ERP) in the left atrium (251 ± 25 ms vs. 233 ± 32 ms, p = 0.04), and in the proximal (207 ± 33 ms vs. 248 ± 34 ms, p < 0.001) and distal (193 ± 33 ms vs. 248 ± 44 ms, p < 0.001) PV than normal BMI patients. Obese patients had higher mean LA pressure (15 ± 5 mm Hg vs. 10 ± 5 mm Hg, p < 0.001) and LA volume index (28 ± 12 ml/m(2) vs. 21 ± 14 ml/m(2), p = 0.006), and lower LA strain (5.5 ± 3.1% vs. 8.8 ± 2.8%; p < 0.001) than normal BMI patients.</AbstractText>Increased LA pressure and volume, and shortened ERP in the left atrium and PV are potential factors facilitating and perpetuating AF in obese patients with AF.</AbstractText>Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,022 | Sinus rhythm versus atrial fibrillation in elderly patients with chronic heart failure--insight from the Cardiac Insufficiency Bisoprolol Study in Elderly. | It has been suggested that patients with chronic HF and atrial fibrillation (AF) may respond differently to beta-blockers than those in sinus rhythm (SR).</AbstractText>In this predefined analysis of the CIBIS-ELD trial, a total of 876 chronic HF patients (164 patients with AF) were randomized to bisoprolol or carvedilol. During the 12-week-treatment phase, beta-blockers were doubled fortnightly up to the target dose or maximally tolerated dose, which was maintained for 4 weeks.</AbstractText>Patients with AF had lower left ventricular ejection fraction (LVEF), exercise capacity, self-rated health, quality of life (QoL) scores for both SF36 physical and psychosocial component, and higher NYHA class than those in SR. Beta-blocker titration was associated with clinical improvement in both AF and SR patients: LVEF, 6-minute walk distance, physical and psychosocial components of QoL scores, self-rated health and NYHA class (p<0.05, for all). The extent of improvement did not differ between patients with AF and in SR and did not differ between bisoprolol and carvedilol. Heart rate (HR) at baseline was higher in the AF group, and remained higher until the end of the trial. Patients with higher baseline HR had larger reductions in HR, regardless of rhythm. AF patients more frequently reached target beta-blocker dose compared to those in SR (p<0.005).</AbstractText>Elderly patients with chronic HF and AF derive comparable clinical benefits from beta-blocker titration as those in SR. Patients with AF tolerate higher beta-blocker doses than those in SR, which appears to be related to higher baseline HR.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,023 | Effect of skeletal muscle Na(+) channel delivered via a cell platform on cardiac conduction and arrhythmia induction. | In depolarized myocardial infarct epicardial border zones, the cardiac sodium channel is largely inactivated, contributing to slow conduction and reentry. We have demonstrated that adenoviral delivery of the skeletal muscle Na(+) channel (SkM1) to epicardial border zones normalizes conduction and reduces induction of ventricular tachycardia/ventricular fibrillation. We now studied the impact of canine mesenchymal stem cells (cMSCs) in delivering SkM1.</AbstractText>cMSCs were isolated and transfected with SkM1. Coculture experiments showed cMSC/SkM1 but not cMSC alone and maintained fast conduction at depolarized potentials. We studied 3 groups in the canine 7d infarct: sham, cMSC, and cMSC/SkM1. In vivo epicardial border zones electrograms were broad and fragmented in sham, narrower in cMSCs, and narrow and unfragmented in cMSC/SkM1 (P<0.05). During programmed electrical stimulation of epicardial border zones, QRS duration in cMSC/SkM1 was shorter than in cMSC and sham (P<0.05). Programmed electrical stimulation-induced ventricular tachycardia/ventricular fibrillation was equivalent in all groups (P>0.05).</AbstractText>cMSCs provide efficient delivery of SkM1 current. The interventions performed (cMSCs or cMSC/SkM1) were neither antiarrhythmic nor proarrhythmic. Comparing outcomes with cMSC/SkM1 and viral gene delivery highlights the criticality of the delivery platform to SkM1 antiarrhythmic efficacy.</AbstractText> |
14,024 | Spatiotemporal behavior of high dominant frequency during paroxysmal and persistent atrial fibrillation in the human left atrium. | Sites of high dominant frequency (DF(peak)) are thought to indicate the location of drivers of atrial fibrillation (AF), but characterization of their spatiotemporal distribution and stability, critical to their relevance as targets for catheter ablation, requires simultaneous global mapping of the left atrium.</AbstractText>Noncontact electrograms recorded simultaneously from 256 left atrial sites during spontaneous AF were analyzed. After subtraction of the ventricular component, fast Fourier transform identified the DF at each site. Focal areas of DF(peak) were defined as those having a DF >20% above all neighboring sites. Twenty-four patients with spontaneous AF (11 paroxysmal and 13 persistent) were studied. In paroxysmal AF, sites of DF(peak) (mean DF, 11.6±2.9 Hz) were observed in 100% of patients (present during 65% of the mapping period). In contrast, DF(peak) was detected in only 31% of patients with persistent AF (P<0.001) and for only 5% of the mapping period (P<0.001). In both groups, locations of DF(peak) varied widely in both consecutive and separated segments of AF (κ coefficient range, -0.07-0.22). Activation sequences around sites of DF(peak) did not demonstrate centrifugal activation that would be expected from focal drivers.</AbstractText>Focal areas of high DF are more frequent in paroxysmal than persistent AF, are spatiotemporally unstable, are not the source of centrifugal activation, and are not, therefore, indicative of fixed drivers of AF. In the absence of spatiotemporal stability, the success of ablation at sites of DF(peak) cannot be explained by elimination of fixed drivers.</AbstractText> |
14,025 | Contribution of fibrosis and the autonomic nervous system to atrial fibrillation electrograms in heart failure. | Fibrotic and autonomic remodeling in heart failure (HF) increase vulnerability to atrial fibrillation (AF). Because AF electrograms (EGMs) are thought to reflect the underlying structural substrate, we sought to (1) determine the differences in AF EGMs in normal versus HF atria and (2) assess how fibrosis and nerve-rich fat contribute to AF EGM characteristics in HF.</AbstractText>AF was induced in 20 normal dogs by vagal stimulation and in 21 HF dogs (subjected to 3 weeks of rapid ventricular pacing at 240 beats per minute). AF EGMs were analyzed for dominant frequency (DF), organization index, fractionation intervals (FIs), and Shannon entropy. In 8 HF dogs, AF EGM correlation with underlying fibrosis/fat/nerves was assessed. In HF compared with normal dogs, DF was lower and organization index/FI/Shannon entropy were greater. DF/FI were more heterogeneous in HF. Percentage fat was greater, and fibrosis and fat were more heterogeneously distributed in the posterior left atrium than in the left atrial appendage. DF/organization index correlated closely with %fibrosis. Heterogeneity of DF/FI correlated with the heterogeneity of fibrosis. Autonomic blockade caused a greater change in DF/FI/Shannon entropy in the posterior left atrium than left atrial appendage, with the decrease in Shannon entropy correlating with %fat.</AbstractText>The amount and distribution of fibrosis in the HF atrium seems to contribute to slowing and increased organization of AF EGMs, whereas the nerve-rich fat in the HF posterior left atrium is positively correlated with AF EGM entropy. By allowing for improved detection of regions of dense fibrosis and high autonomic nerve density in the HF atrium, these findings may help enhance the precision and success of substrate-guided ablation for AF.</AbstractText> |
14,026 | Holter monitoring and long-term prognosis in hypertrophic cardiomyopathy. | Limited data are available regarding Holter monitoring for cardiovascular events except for ventricular tachycardia as a risk marker for sudden death in hypertrophic cardiomyopathy (HCM). We aimed to examine Holter findings in relation to the long-term prognosis in patients with HCM.</AbstractText>Ambulatory Holter monitoring was performed in 106 HCM patients with sinus rhythm. All were prospectively followed for the composite endpoint of sudden death, cardiovascular death, and hospitalization for heart failure or stroke associated with atrial fibrillation.</AbstractText>Cardiovascular events occurred in 19 patients during a mean follow-up of 10.1 years. Neither arrhythmia information nor autonomic information as assessed by heart rate variability and turbulence significantly differed between HCM patients with and without cardiovascular events. Average heart rates were lower in HCM patients with cardiovascular events (64.7 ± 11.2 beats/min) than in those without (73.7 ± 10.2 beats/min, p = 0.001). Multivariate Cox proportional hazards regression analysis after adjustment for baseline characteristics showed that lower average heart rate remained an independent predictor of cardiovascular events (HR: 0.47 per 10 increase; 95% CI: 0.25-0.87; p = 0.016).</AbstractText>Average heart rate on Holter monitoring predicted long-term prognosis in our cohort. Further multicenter studies are needed to confirm our results.</AbstractText>Copyright © 2012 S. Karger AG, Basel.</CopyrightInformation> |
14,027 | Implantable cardioverter-defibrillators: indications and unresolved issues. | Since the implantable cardioverter-defibrillator was first used clinically in 1980, several large randomized controlled trials have shown that therapy with this device can be beneficial in various patient populations. Evidence suggests that this therapy is useful in the secondary prevention of sudden cardiac death among patients who have survived arrhythmic events. Several trials have also shown the usefulness of implantable cardioverter-defibrillator therapy in the primary prevention of sudden cardiac death in patients with coronary artery disease and nonischemic cardiomyopathy. Other data support the use of this device for various infiltrative and inherited conditions. When used with cardiac resynchronization therapy, implantable cardioverter-defibrillators have improved survival rates and quality of life in patients with severe heart failure. Further research is needed to examine the potential benefits of implantable cardioverter-defibrillators in elderly, female, and hemodialysis-dependent patients, and to determine the optimal waiting period for implantation after myocardial infarction, coronary revascularization, and initial heart-failure diagnosis. |
14,028 | Pharmacological treatment options for hypertrophic cardiomyopathy: high time for evidence. | Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease, affecting over one million individuals in Europe. Hypertrophic cardiomyopathy patients often require pharmacological intervention for control of symptoms, dynamic left ventricular outflow obstruction, supraventricular and ventricular arrhythmias, and microvascular ischaemia. Current treatment strategies in HCM are predicated on the empirical use of long-standing drugs, such as beta-adrenergic and calcium blockers, although with little evidence supporting their clinical benefit in this disease. In the six decades since the original description of the disease, <50 pharmacological studies enrolling little over 2000 HCM patients have been performed, the majority of which were small, non-randomized cohorts. As our understanding of the genetic basis and pathophysiology of HCM improves, the availability of transgenic and preclinical models uncovers clues to novel and promising treatment modalities. Furthermore, the number of patients identified and followed at international referral centres has grown steadily over the decades. As a result, the opportunity now exists to implement adequately designed pharmacological trials in HCM, using established as well as novel drug therapies, to potentially intervene on the complex pathophysiology of the disease and alter its natural course. Therefore, it is timely to review the available evidence for pharmacological therapy of HCM patients, highlight the most relevant gaps in knowledge, and address some of the most promising areas for future pharmacological research, in an effort to move HCM into the era of evidence-based management. |
14,029 | Event synchronous adaptive filter based atrial activity estimation in single-lead atrial fibrillation electrocardiograms. | In this paper, an event synchronous adaptive filter (ESAF) is proposed to estimate atrial activity (AA) from a single-lead AF ECG in real time. The proposed ESAF is a kind of adaptive filter designed to have the reference fed with the impulse train synchronized with the R peak in a raw atrial fibrillation (AF) ECG and to input the timely delayed AF ECG into the primary input. To assess the performance, for ten simulated AF ECGs, the cross-correlation coefficient (ρ) and the normalized mean square error (NMSE) between estimated AAs and ten original simulated AAs were calculated and, for ten real AF ECGs, the ventricular residue (VR) in QRS interval and similarity (S) in non-QRS interval were computed. As a result, these four parameters were revealed as ρ = 0.938 ± 0.016 and NMSE = 0.243 ± 0.051 for simulated AF ECGs and VR = 1.190 ± 0.476 and S = 0.967 ± 0.041 for real AF ECGs. These results were found to be better than those of the averaged beat subtraction (ABS) method, which had been previously considered the only way to estimate AA automatically in real time. In conclusion, even with single-lead AF ECGs, the proposed method estimated AAs accurately and calculated the atrial fibrillatory frequencies, the most valuable index in AF maintenance and therapy evaluation, with a remarkably low computational cost. |
14,030 | The prognostic significance of right ventricular tissue Doppler parameters in patients with left ventricular systolic heart failure: an observational cohort study. | To investigate the value of tissue Doppler imaging (TDI) measurements of right ventricular (RV) systolic and diastolic function as a predictor of long term cardiovascular outcomes in patients with left ventricular (LV) systolic heart failure.</AbstractText>In patients with LV systolic heart failure, RV function has been shown to be an important predictor of outcome. TDI is probably a clinically useful method for assessing RV function. The studies published so far have had a rather short follow-up period and have excluded patients with atrial fibrillation.</AbstractText>156 patients admitted to the cardiology department due to decompensated heart failure were included in this observational cohort study. 19% had atrial fibrillation. An echocardiographic examination was performed at entry to the study. The patients were then followed for a mean of 829 days. The primary endpoint was cardiovascular mortality or hospitalisation for decompensated heart failure.</AbstractText>43 patients (28%) died from cardiovascular causes and 55 patients (35%) patients were hospitalised. 80 patients (51%) reached the study endpoint. Only age and a combined systolic and diastolic TDI parameter (s'r + e'r < 18.5 cm/s) of the right ventricle were independent predictors of cardiovascular outcome (HR 1.99, p=0.007).</AbstractText>A combined measure of RV systolic and diastolic function, using TDI, can be used as an independent predictor of outcome in patients with LV systolic heart failure.</AbstractText> |
14,031 | Atrial fibrillation, blood loss, and transfusion in patients with left ventricular dysfunction: what is the effect of cardiopulmonary bypass? | Despite advancements in surgical technique, intensive care methods and pharmaceutical prophylaxis atrial fibrillation (AF) after on-pump coronary artery bypass remains common. Transfusion, blood loss, and cardiopulmonary bypass (CPB) have been identified as risk factors for AF and adverse outcomes such as early mortality. This study examines outcomes in patients with left ventricular dysfunction after revascularization with and without CPB. A systematic literature review identified 22 studies including 7,454 patients. Meta-analysis through subgroup analysis of the highest-quality studies revealed that the off-pump coronary artery bypass (OPCAB) technique is associated with a significantly lower incidence of blood loss, transfusion requirement, reoperation for bleeding, and length of stay. There was also a reduction in the incidence of AF in the OPCAB group but this was not statistically significant (odds ratio = 0.77, 95% confidence interval 0.58-1.02, p = 0.07). The results strengthen research suggesting that CPB has a damaging effect on hemostasis and subsequent transfusion requirements in this patient group. More research is required to assess the association between OPCAB and AF in patients with ventricular dysfunction. |
14,032 | Atrial fibrillation induction by transesophageal electrophysiology studies in patients with asymptomatic ventricular preexcitation. | Ventricular preexcitation is a conduction abnormality caused by an accessory pathway bridging the atria and ventricles. If the accessory pathway conducts rapidly during atrial fibrillation (AFib), sudden death may result. The purpose of this study was to determine the ability of transesophageal electrophysiology studies (TEEPS) to induce AFib in pediatric patients with asymptomatic ventricular preexcitation (aVPE).</AbstractText>A retrospective review of patients with aVPE who had a TEEPS was conducted. Inclusion criteria were evidence of ventricular preexcitation on electrocardiogram; age <18 years; and no history of tachycardia, palpitations, or syncope. Data gathered included age, weight, height, form of sedation, and TEEPS results. If AFib was induced, patients were classified as at risk of sudden death if the shortest preexcited RR interval during AFib was <250 ms or no risk if ≥ 250 ms.</AbstractText>A total of 26 patients met the inclusion criteria, with average age of 11.9 years, weight of 48.9 kg, and height of 149.2 cm. During the procedure, nine patients underwent conscious sedation (34.6%), and 17 underwent general anesthesia (65.4%). AFib was induced in 23 patients (88.5%), of whom 17 (73.9%) had no risk and six (26.1%) had risk. No statistical differences were noted in age, weight, height, or form of sedation when comparisons were made between AFib induction and no AFib induction.</AbstractText>TEEPS induced AFib in 88.5% of patients. Age, weight, height, and form of sedation had no effect upon AFib inducibility. TEEPS is an effective modality to induce AFib in pediatric patients with aVPE.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,033 | Stroke and Stroke-like Episodes in Muscle Disease. | Though not obvious at a first glance, myopathies may be associated with ischemic stroke. Stroke-like episodes resemble ischemic stroke only to some extent but are a unique feature of certain mitochondrial disorders with a pathogenesis at variance from that of ischemic stroke. Only limited data are available about ischemic stroke in pri-mary myopathies and the management of stroke-like episodes in mitochondrial disorders. This review aims to summarize and discuss current knowledge about stroke in myopathies and to delineate stroke-like episodes from ischemic stroke.</AbstractText>Literature review via PubMED using the search terms "stroke", "cerebrovascular", "ischemic event", "stroke-like episode", "stroke-mimic", "mitochondrial disorder".</AbstractText>Stroke in myopathies is most frequently cardioembolic due to atrial fibrillation or atrial flutter, dilated cardio-myopathy, or left-ventricular hypertrabeculation (noncompaction). The second most frequent cause of stroke in myopathies is angiopathy from atherosclerosis or vasculitis, which may be a feature of inflammatory myopathies. Athero-sclerosis may either result from classical risk factors, such as diabetes, arterial hypertension, hyperlpidemia, or smoking, associated with muscle disease, or may be an inherent feature of a mitochondrial disorder. In case of severe heart failure from cardiomyopathy as a manifestation of muscle disease low flow infarcts may occur. Thrombophilic stroke has been described in polymyositis and dermatomyositis in association with anti-phospholipid syndrome. Stroke-like episodes occur particularly in mitochondrial encephalopathy, lactacidosis and stroke-likeepisode syndrome but rarely also in Leigh-syndrome and other mitochondrial disorders. Stroke-like episodes are at variance from ischemic stroke, pathogenically, clinically and on imaging. They may be the manifestation of a vascular, metabolic or epileptic process and present with predominantly vasogenic but also cytotoxic edema on MRI. Differentiation between ischemic stroke and stroke-like episodes is essential in terms of management and prognosis. Management of ischemic stroke in patients with myopathy is not at variance from the treatment of ischemic stroke in non-myopathic patients. There is no standardized treatment of stroke-like episodes but there is increasing evidence that these patients profit from the administration of L-arginine and conse-quent antiepileptic treatment if associated with seizure activity.</AbstractText>Ischemic stroke may be a complication of myopathy and needs to be delineated from stroke-like episodes, which are unique to mitochondrial disorders, particularly mitochondrial encephalopathy, lactacidosis and stroke-likeepisode syndrome. Ischemic stroke in myopathies is most frequently cardioembolic and treatment is not at variance from non-myopathic ischemic stroke. Treatment of stroke-like episodes is not standardized but seems to respond to L-arginine and adequate antiepileptic treatment.</AbstractText> |
14,034 | Vitamin C compromises cardiac resuscitability in a rat model of ventricular fibrillation. | Resuscitation from cardiac arrest is partly limited by progressive reduction in left ventricular distensibility, leading to decreased hemodynamic efficacy of cardiopulmonary resuscitation (CPR). Reduction in left ventricular distensibility has been linked to loss of mitochondrial bioenergetic function that can result from oxidative injury. Attenuation of oxidative injury by administration of vitamin C during CPR may help maintain left ventricular distensibility and favor resuscitability and survival. Ventricular fibrillation was electrically induced in 2 series of 16 rats each and left untreated for 10 minutes. Resuscitation was attempted by 8 minutes of CPR and delivery of electrical shocks. Dehydroascorbate (DHA)-an oxidized form of vitamin C that enters the cell via glucose transporters-was used in series 1 and ascorbic acid (AA)-the reduced form of vitamin C that enters the cell via specialized AA transporters-in series 2. In each series, rats were randomized 1:1 to receive a 250 mg/kg right atrial bolus of DHA or AA or vehicle immediately before chest compression. Left ventricular distensibility-measured as the ratio between coronary perfusion pressure and compression depth-was numerically lower (not significant) in rats that received DHA (1.6 ± 0.2 vs. 1.9 ± 0.7 mm Hg/mm) and AA (1.8 ± 0.6 vs. 1.9 ± 0.3 mm Hg/mm). In addition, resuscitability was compromised by DHA (2/8 vs. 7/8; P = 0.041) and by AA (0/8 vs. 5/8; P = 0.026). AA levels in mitochondria were no different than control. Vitamin C failed to preserve left ventricular distensibility during CPR and had detrimental effects on resuscitability, suggesting possible disruption of protective signaling mechanisms during oxidative stress by vitamin C. |
14,035 | A case of idiopathic ventricular fibrillation in which implanted loop recorder was useful in application decision for implantation of implantable cardioverter-defibrillator. | Establishing a symptom-rhythm correlation in patients with unexplained syncope is complicated because of its sporadic, infrequent, and unpredictable nature. Recently, an implantable loop recorder (ILR) has become available to evaluate undiagnosed recurrent arrhythmic episodes particularly in unexplained syncopes, and its usefulness has been reported in patients with recurrent syncopes that remain unexplained after conventional work-up. A 65-year-old man was referred to our hospital for loss of consciousness with nocturnal paroxysmal seizures. He had experienced several similar episodes. No family history of sudden death was evident, and apparent structural heart disease was absent. Coronary angiography with intracoronary ergonovine provocation showed vasospasm in left coronary artery without organic stenosis. Ventricular tachyarrhythmias were not induced by programmed electrical stimuli. According to the guideline, he was at once categorized as having class IIb indication for implantable cardioverter defibrillator implantation. However, his symptoms were not relieved despite administration of anti-anginal medications including nitrates and calcium antagonist. Implantation of an ILR was performed and revealed an episode of ventricular fibrillation during generalized-convulsion attack during sleep. ILR is useful in determining the presence of fatal arrhythmias during syncope, although conventional diagnostic testing, such as electrocardiogram, Holter monitoring, and external loop recording, is inconclusive. |
14,036 | Torsadogenic index: a proposal to improve survival rates in cardiac arrests due to prescribed drugs. | Since unexpected sudden deaths have been reported with the use of diverse non-cardiac drugs, cardio-safety experts focused their attention on security measures to improve survival rates in heart stoppages due to this prescribed drugs (Inchauspe 2010a). Considering that prolongation of the QTc is a reliable marker of a menacing arrhythmia called torsade de pointes (TdP) - that can progress to ventricular fibrillation, application of Bazett, or Rautaharhu formulas can lead to a proper predictive valuation of a "torsadogenic risk." Case-analysis raises up the proposal that QTc or QTp will allow to identify high risk groups; performs a close pharmaco-vigilance and legally register ECG follow-up, avoiding unnecessary withdrawal of useful drugs from market. |
14,037 | Brugada type 1 electrocardiogram unmasked by a febrile state following syncope. | Brugada syndrome is a genetic disease characterized by persistent or transient ST elevation in the right precordial electrocardiogram (ECG) leads with or without right bundle branch block. It represents an increased risk for sudden cardiac death despite a structurally normal heart. Brugada-type ECG can be unmasked and induced by several circumstances. We report on a 24-year-old male patient who experienced a syncopal episode and manifested Brugada type 1 ECG during a febrile state. His ECG changed to normal after treatment of fever. A single-chamber ICD was implanted to the patient because of syncope, fever-induced type I Brugada ECG pattern, and ventricular fibrillation during ajmaline challenge. |
14,038 | A study of risk factors of stroke in patients admitted in Manipal Teaching Hospital, Pokhara. | Stroke is usually end result of predisposing conditions that originated years before the ictus. Identification of its modifiable risk factors can help in planning preventive strategies.</AbstractText>To study the risk factors of stroke in adult patients.</AbstractText>A hospital based prospective cross sectional study was carried out in 160 stroke patients admitted in Manipal Teaching Hospital, Pokhara from November 2007- October 2010. Diagnosis of stroke was confirmed by CT scan of brain. Patients were then investigated for presence of conventional risk factors. The data was statistically analysed using Epi-Info.</AbstractText>The mean age of stroke patients was 65.98 years +/- 10.69 with 126 (78.8%) of patients belonging to age group = 60 years. It afflicted higher percentage of males 104 (65%) than females 56 (35%). Analysis of stroke subtypes showed preponderance of haemorrhagic stroke in 85 (53.1%) as against infarction in 75 (46.9%) of cases. Other conventional modifiable risk factors were seen as follows: hypertension 98 (61.2 %), cigarette smoking 95 (59.4%), alcohol use 43 (26.9%), left ventricular hypertrophy 44 (27.5%), atrial fibrillation 37(23%), elevated triglyceride 37(23%), diabetes mellitus 15 (9.3%) and elevated total cholesterol 12 (7.5%). Multiple risk factors (=2) were seen in 122 (76.5 %) cases.</AbstractText>The maximum occurrence of stroke was seen in patients > 60 years. Overall male preponderance and higher occurrence of haemorrhagic stroke was seen in our study. Significant risk factors in order of descending order were hypertension, cigarette smoking, left ventricular hypertrophy, alcohol use, atrial fibrillation and elevated triglycerides.</AbstractText> |
14,039 | Mechanical CPR devices compared to manual CPR during out-of-hospital cardiac arrest and ambulance transport: a systematic review. | The aim of this paper was to conduct a systematic review of the published literature to address the question: "In pre-hospital adult cardiac arrest (asystole, pulseless electrical activity, pulseless Ventricular Tachycardia and Ventricular Fibrillation), does the use of mechanical Cardio-Pulmonary Resuscitation (CPR) devices compared to manual CPR during Out-of-Hospital Cardiac Arrest and ambulance transport, improve outcomes (e.g. Quality of CPR, Return Of Spontaneous Circulation, Survival)".</AbstractText>Databases including PubMed, Cochrane Library (including Cochrane database for systematic reviews and Cochrane Central Register of Controlled Trials), Embase, and AHA EndNote Master Library were systematically searched. Further references were gathered from cross-references from articles and reviews as well as forward search using SCOPUS and Google scholar. The inclusion criteria for this review included manikin and human studies of adult cardiac arrest and anti-arrhythmic agents, peer-review. Excluded were review articles, case series and case reports.</AbstractText>Out of 88 articles identified, only 10 studies met the inclusion criteria for further review. Of these 10 articles, 1 was Level of Evidence (LOE) 1, 4 LOE 2, 3 LOE 3, 0 LOE 4, 2 LOE 5. 4 studies evaluated the quality of CPR in terms of compression adequacy while the remaining six studies evaluated on clinical outcomes in terms of return of spontaneous circulation (ROSC), survival to hospital admission, survival to discharge and Cerebral Performance Categories (CPC). 7 studies were supporting the clinical question, 1 neutral and 2 opposing.</AbstractText>In this review, we found insufficient evidence to support or refute the use of mechanical CPR devices in settings of out-of-hospital cardiac arrest and during ambulance transport. While there is some low quality evidence suggesting that mechanical CPR can improve consistency and reduce interruptions in chest compressions, there is no evidence that mechanical CPR devices improve survival, to the contrary they may worsen neurological outcome.</AbstractText> |
14,040 | Trends in the use of electrical cardioversion for atrial fibrillation: influence of major trials and guidelines on clinical practice. | The purpose of the present study was to assess the trends in the use of ECV following published studies that had compared rhythm and rate control strategies on atrial fibrillation (AF), and the recommendations included in the current clinical practice guidelines.</AbstractText>The REVERCAT is a population-based assessment of the use of electrical cardioversion (ECV) in treating persistent AF in Catalonia (Spain). The initial survey was conducted in 2003 and the follow-up in 2010.</AbstractText>We observed a decrease of 9% in the absolute numbers of ECV performed (436 in 2003 vs. 397 in 2010). This is equivalent to 27% when considering population increases over this period. The patients treated with ECV in 2010 were younger, had a lower prevalence of previous embolism, a higher prevalence of diabetes, and increased body weight. Underlying heart disease factors indicated, in 2010, a higher proportion of NYHA ≥ II and left ventricular ejection fraction <30%. We observed a reduction in the number of ECV performed in 16 of the 27 (67%) participating hospitals. However, there was an increase of 14% in the number of procedures performed in tertiary hospitals, and was related to the increasing use of ECV as a bridge to AF ablation. Considering the initial number of patients treated with ECV, the rate of sinus rhythm at 3 months was almost unchanged (58% in 2003 vs. 57% in 2010; p=0.9) despite the greater use of biphasic energy in 2010 and a similar prescription of anti-arrhythmic drugs.</AbstractText>Although we observed a decrease in the number of ECVs performed over the 7 year period between the two studies, this technique remains a common option for treating patients with persistent AF. The change in the characteristics of candidate patients did not translate into better outcomes.</AbstractText> |
14,041 | Inhibition of intercellular coupling stabilizes spiral-wave reentry, whereas enhancement of the coupling destabilizes the reentry in favor of early termination. | Spiral-wave (SW) reentry is a major organizing principle of ventricular tachycardia/fibrillation (VT/VF). We tested a hypothesis that pharmacological modification of gap junction (GJ) conductance affects the stability of SW reentry in a two-dimensional (2D) epicardial ventricular muscle layer prepared by endocardial cryoablation of Langendorff-perfused rabbit hearts. Action potential signals were recorded and analyzed by high-resolution optical mapping. Carbenoxolone (CBX; 30 μM) and rotigaptide (RG, 0.1 μM) were used to inhibit and enhance GJ coupling, respectively. CBX decreased the space constant (λ) by 36%, whereas RG increased it by 22-24% (n = 5; P < 0.01). During centrifugal propagation, there was a linear relationship between the wavefront curvature (κ) and local conduction velocity (LCV): LCV = LCV(0) - D·κ (D, diffusion coefficient; LCV(0), LCV at κ = 0). CBX decreased LCV(0) and D by 27 ± 3 and 57 ± 3%, respectively (n = 5; P < 0.01). RG increased LCV(0) and D by 18 ± 3 and 54 ± 5%, respectively (n = 5, P < 0.01). The regression lines with and without RG crossed, resulting in a paradoxical decrease of LCV with RG at κ > ~60 cm(-1). SW reentry induced after CBX was stable, and the incidence of sustained VTs (>30 s) increased from 38 ± 4 to 85 ± 4% after CBX (n = 18; P < 0.01). SW reentry induced after RG was characterized by decremental conduction near the rotation center, prominent drift and self-termination by collision with the anatomical boundaries, and the incidence of sustained VTs decreased from 40 ± 5 to 17 ± 6% after RG (n = 13; P < 0.05). These results suggest that decreased intercellular coupling stabilizes SW reentry in 2D cardiac muscle, whereas increased coupling facilitates its early self-termination. |
14,042 | Incidence of ventricular arrhythmia and associated patient outcomes in hospitalized acute coronary syndrome patients in Saudi Arabia: findings from the registry of the Saudi Project for Assessment of Acute Coronary Syndrome (SPACE). | Mortality in acute coronary syndrome (ACS) patients with ventricular arrhythmia (VA) has been shown to be higher than those without VA. However, there is a paucity of data on VA among ACS patients in the Middle Eastern countries.</AbstractText>Prospective study of patients admitted in 17 government hospitals with ACS between December 2005 and December 2007.</AbstractText>Patients were categorized as having VA if they experienced either ventricular fibrillation (VF) or sustained ventricular tachycardia (VT) or both.</AbstractText>Of 5055 patients with ACS enrolled in the SPACE registry, 168 (3.3%) were diagnosed with VA and 151 (98.8%) occurred in-hospital. The vast majority (74.4%) occurred in patients with ST-segment elevation myocardial infarction. In addition, males were twice as likely to develop VA than females (OR 1.7; 95% CI 1.13). Killip class >I (OR 2.0; 95% CI 1.3-3.1); and systolic blood pressure <90 mm Hg (OR 6.4; 95% CI 3.5-11.8) were positively associated with VA. Those admitted with hyperlipidemia (OR 0.49; 95% CI 0.3-0.7) had a lower risk of developing VA. Adverse in-hospital outcomes including re-myocardial infarction, cardiogenic shock, congestive heart failure, major bleeding, and stroke were higher for patients with VA (P≤.01 for all variables) and signified a poor prognosis. The in-hospital mortality rate was significantly higher in VA patients compared with non-VA patients (27% vs 2.2%; P=.001).</AbstractText>In-hospital VA in Saudi patients with ACS was associated with remarkably high rates of adverse events and increased in-hospital mortality. Using a well-developed registry data with a large number of patients, our study documented for the first time the prevalence and risk factors of VA in unselected population of ACS.</AbstractText> |
14,043 | Reduction in life-threatening ventricular tachyarrhythmias in statin-treated patients with nonischemic cardiomyopathy enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy). | This study hypothesized that time-dependent statin therapy will reduce the risk of life-threatening ventricular tachyarrhythmias among patients with nonischemic cardiomyopathy (NICM) enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy).</AbstractText>Prior studies suggested that statin therapy exerts antiarrhythmic properties among patients with coronary artery disease. However, data regarding the effect of statins on arrhythmic risk among patients with NICM are limited.</AbstractText>Multivariate Cox proportional hazards regression modeling was used to assess the effect of statin therapy, evaluated as a time-dependent covariate, on the risk of appropriate defibrillator therapy for fast ventricular tachycardia (VT) (defined as a rate faster than 180 beats/min)/ventricular fibrillation (VF) or death (primary endpoint) and appropriate defibrillator shocks (secondary endpoint) among 821 patients with NICM enrolled in the MADIT-CRT trial.</AbstractText>Statin users (n = 499) were older and had a higher prevalence of diabetes and hypertension yet were less frequently smokers. Multivariate analysis showed that time-dependent statin therapy was independently associated with a significant 77% reduction in the risk of fast VT/VF or death (p < 0.001) and with a significant 46% reduction in the risk of appropriate implantable cardioverter defibrillator shocks (p = 0.01). Consistent with these findings, the cumulative probability of fast VT/VF or death at 4 years of follow-up was significantly lower among patients who were treated with statins (11%) as compared with study patients who were not treated with statins (19%; p = 0.006 for the overall difference during follow-up).</AbstractText>Statin use was associated with a significant reduction in the risk of life-threatening ventricular tachyarrhythmias among patients with NICM.</AbstractText>Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,044 | Transgenic insights linking pitx2 and atrial arrhythmias. | Pitx2 is a homeobox transcription factor involved in left-right signaling during embryogenesis. Disruption of left-right signaling in mice within its core nodal/lefty cascade, results in impaired expression of the last effector of the left-right cascade, Pitx2, leading in many cases to absence or bilateral expression of Pitx2 in lateral plate mesoderm (LPM). Loss of Pitx2 expression in LPM results in severe cardiac malformations, including right cardiac isomerism. Pitx2 is firstly expressed asymmetrically in the left but not right LPM, before the cardiac crescent forms, and subsequently, as the heart develops, becomes confined to the left side of the linear heart tube. Expression of Pitx2 is remodeled during cardiac looping, becoming localized to the ventral portion of the developing ventricular chambers, while maintaining a distinct left-sided atrial expression. The importance of Pitx2 during cardiogenesis has been illustrated by the complex and robust cardiac defects observed on systemic deletion of Pitx2 in mice. Lack of Pitx2 expression leads to embryonic lethality at mid-term, and Pitx2-deficient embryos display isomeric hearts with incomplete closure of the body wall. However, whereas the pivotal role of Pitx2 during cardiogenesis is well sustained, its putative role in the fetal and adult heart is largely unexplored. Recent genome-wide association studies have identified several genetic variants highly associated with atrial fibrillation (AF). Among them are genetic variants located on chromosome 4q25 adjacent to PITX2. Since then several transgenic approaches have provided evidences of the role of the homeobox transcription factor PITX2 and atrial arrhythmias. Here, we review new insights into the cellular and molecular links between PITX2 and AF. |
14,045 | Overdrive ventricular pacing in pacemaker recipients with permanent atrial fibrillation and sleep apnea. | Cardiac pacing is ineffective in obstructive sleep apnea (SA), but it can alleviate central SA/Cheyne-Stokes respiration (CSA) in patients with heart failure (HF). We examined whether overnight overdrive ventricular pacing (OVP) has an effect on SA in pacemaker recipients with permanent atrial fibrillation (AF).</AbstractText>An apnea-hypopnea index (AHI) ≥ 15 was confirmed in 28/38 patients screened by finger pulse oximetry during overnight ventricular pacing at a backup rate of 40 bpm (BUV40). These patients (23 men, 77.9 ± 7.6 y, BMI 27.6 ± 5.1 kg/m(2)) were randomly assigned to 2 consecutive nocturnal ventilation polygraphies with BUV40 versus OVP at 20 bpm above the mean nocturnal heart rate observed during screening.</AbstractText>During BUV40 versus OVP, (1) mean heart rate was 49 ± 8 versus 71 ± 8 bpm (p < 0.0001) and percent ventricular pacing 36% ± 38% versus 96% ± 6% (p < 0.0001); (2) AHI was 35.4 ± 11.9 versus 32.5 ± 15.5 (p = ns), central AHI 23.9 ± 11.8 versus 19.1 ± 12.7 (p < 0.001), and obstructive AHI 11.6 ± 13.1 versus 13.5 ± 15.9 (p = ns). In 15/28 patients without HF, mean left ventricular ejection fraction (LVEF) was 51% ± 17%, AHI was 37.6 ± 11.0 during BUV40 and 39.0 ± 11.5 during OVP, versus 32.8 ± 12.9 and 24.9 ± 16.5 in 13/28 patients with HF (p = 0.02) and mean LVEF 35% ± 15% (p = 0.01). Between the 2 subgroups, (1) central AHI was 23.6 ± 12.4 during BUV40 and 21.5 ± 14.0 during OVP versus 24.1 ± 11.6 and 16.2 ± 10.7 (p = 0.05); (2) obstructive AHI was 14.0 ± 13.7 during BUV40 and 17.6 ± 16.5 during OVP versus 8.8 ± 12.3 and 8.7 ± 14.3 (p = ns).</AbstractText>The prevalence of SA, predominantly central, was high in our pacemaker recipients with permanent AF. In those with HF, a single overnight OVP resulted in modest improvement in central events.</AbstractText> |
14,046 | Sudden cardiac arrest due to subtotal absence of left-sided pericardium--case report and review of the literature. | Congenital absence of the pericardium is a very rare cardiac malformation, usually diagnosed fortuitously on autopsy or surgery. Symptoms related to these abnormalities are usually benign, and fatalities reported in the literature are almost exclusively secondary to herniation of the heart through a partial defect. We present the unusual case of a 44-year-old woman admitted for sudden cardiac arrest. Initial evaluation suggested acute anterior myocardial infarction, but further investigation ruled out coronary heart disease. No arrhythmia could be initiated on electrophysiological study, and absence of most of the left pericardium was confirmed by cardiac magnetic resonance imaging. After the exclusion of common etiologies such as idiopathic ventricular fibrillation, transient great vessel torsion due to hypermobility of the heart with secondary malignant arrhythmia was considered to be the most likely mechanism for the sudden cardiac arrest. A review of the available literature on clinical presentation, diagnostic tools, and therapeutic options is also presented. |
14,047 | [The organization and management of First Aid in the workplace: critical issues and innovations to be introduced]. | Develop an effective First Aid's system in workplaces is significantly important to the outcomes of accidents at work, thus contributing positively to create healthy and safe environments, improving responsible attitude and risk perception by workers. The italian regulation (D. Lgs. 81/08; DM 388/03) gives an important role to First Aid within the system for managing health and safety in workplaces and requires the employers to designate and train workers and organize facilities in the workplace. However, to ensure that First Aid's system actually contributes to increasing health and safety in workplaces, it's necessary to verify its effectiveness, beyond the law compliance. The article stands to evaluate the critical issues and related innovations to be introduced in this context, by analyzing data from literature and field experiences involving actors in the prevention system. The goal is to provide suggestions and action proposals to improve first aid's system in workplaces, paying particular attention to the aiders training (selection, motivation, teaching methods, retraining), as well as introduce to innovations to allow an immediate and timely emergency response (company equipments, other useful devices). On this last aspect, it has given particular emphasis to the introduction of semi-automatic defibrillator (AED), which is essential in case of sudden cardiac arrest with ventricular fibrillation, and special aiders training by means of BLSD (Basic Life Support and Defibrillation) courses based on international guidelines. |
14,048 | Cardiac resynchronization therapy after atrioventricular junction ablation for symptomatic atrial fibrillation: a meta-analysis. | Atrioventricular junction (AVJ) ablation with permanent pacing improves symptoms in selected patients with atrial fibrillation (AF). The optimal pacing modality after AVJ ablation remains unclear. We performed a meta-analysis of randomized controlled trials to examine whether cardiac resynchronization therapy (CRT) is superior to right ventricular (RV) pacing in this patient population.</AbstractText>We searched the MEDLINE and EMBASE databases for studies evaluating the effect of CRT vs. RV pacing after AVJ ablation for AF. Pooled risk ratios (RRs) and mean differences with 95% confidence intervals (CIs) were calculated for categorical and continuous outcomes, respectively, using a random effects model. Five trials involving 686 patients (413 in CRT and 273 in RV pacing group) were included in the analysis. On the basis of the pooled estimate across the studies, CRT resulted in a non-significant reduction in mortality (RR = 0.75, 95% CI 0.43-1.30; P= 0.30) and a significant reduction in hospitalizations for heart failure (RR = 0.38, 95% CI = 0.17-0.85; P= 0.02) compared with RV pacing. Cardiac resynchronization therapy did not improve 6 min walk distance (mean difference 15.7, 95% CI -7.2 to 38.5 m; P= 0.18) and Minnesota Living with Heart Failure quality-of-life score (mean difference -3.0, 95% CI -8.6 to 2.6; P= 0.30) compared with RV pacing. The change in left ventricular ejection fraction between baseline and 6 months favoured CRT (mean change 2.0%, 95% CI 1.5-2.4%; P< 0.001).</AbstractText>Cardiac resynchronization therapy may be superior to RV pacing in patients undergoing AVJ ablation for AF. Further studies, adequately powered to detect clinical outcomes, are required.</AbstractText> |
14,049 | [Targeted temperature management in critical care : current 2011 recommendations]. | Since October 2011 new guidelines exist for temperature management in critical care. According to the guidelines the term targeted temperature management (TTM) should replace the term therapeutic hypothermia. There is now a strong recommendation for TTM using 32-34°C as the preferred treatment for out-of-hospital adult cardiac arrest with a first registered electrocardiography rhythm of ventricular fibrillation or pulseless ventricular tachycardia and still unconscious after restoration of spontaneous circulation. A TTM of 32.5-35.5°C is also recommended for the treatment of term newborns who sustain asphyxia and exhibit acidosis and/or encephalopathy. |
14,050 | Systematic review and meta-analysis of out-of-hospital cardiac arrest and race or ethnicity: black US populations fare worse. | Several studies have reported racial/ethnic variation in out-of-hospital cardiac arrest (OOHCA) characteristics, which engendered varying conclusions. We performed a systematic review and meta-analysed the evidence for differences in OOHCA survival when considering the patient's race and/or ethnicity.</AbstractText>We searched Medline and EMBASE databases up to and including 1 Oct 2011 for studies investigating racial/ethnic differences in OOHCA characteristics, supplemented by manual searches of bibliographies of relevant studies. We selected studies of any relevant design that measured OOHCA characteristics and stratified them by ethnic group. Two independent reviewers extracted information on the study population, including: race and/or ethnicity, location, age and OOHCA variables as per the Utsein template. We performed a meta-analysis of the studies comparing the black and white patients.</AbstractText>1701 potentially relevant articles were identified in our systematic search. Of these, 22 articles describing original studies were reviewed after fulfilling our inclusion criteria. Although 19 studies (18 within the United States (US)) compared the black and white population, only 15 fulfilled our quality assessment criteria and were meta-analysed. Compared to white patients, black patients were less likely to receive bystander cardiopulmonary resuscitation (OR = 0.66, 95%CI = 0.55-0.78), have a witnessed arrest (OR = 0.77, 95%CI = 0.72-0.83) or have an initial ventricular fibrillation/ventricular tachycardia arrest rhythm (OR = 0.66, 95%CI = 0.58-0.76). Black patients had lower rates of survival following hospital admission (OR = 0.59, 95%CI = 0.48-0.72) and discharge (OR = 0.74, 95%CI = 0.61-0.90).</AbstractText>Our work highlights the significant discrepancy in OOHCA characteristics and patient survival in relation to the patient's race, with the black population faring less well across all stages. Most studies compared black and white populations within the US, so research elsewhere and with other ethnic groups is needed. This review exposes an inequality that demands urgent action.</AbstractText> |
14,051 | Successful percutaneous flow redirection to the juvenile patient of fulminant myocarditis treated with percutaneous cardio-pulmonary support. | Percutaneous cardio-pulmonary support (PCPS) system is a powerful life support system for acute circulation failure. This life support system requires more than a fourteen-French cannula to the artery. Insertion with such a large tube sometimes induces damage to the peripheral circulation. We experienced the successful salvage with percutaneous flow redirection from the acute circulation failure of the limb in a juvenile patient with fulminant myocarditis treated with PCPS. The case is a 12-year-old girl. She was admitted to our hospital by ambulance. Ventricular fibrillation was found at her admission, and defibrillation was not effective. We attached her to the PCPS life support system. After this procedure, her left leg color turned to pale, and no arterial sound was heard with Doppler flow-meter. We inserted a four French vessel sheath to the superficial artery with the guidewire guidance which was inserted to left superficial artery from the contra lateral femoral artery. The parallel blood flow circulation to the four-French sheath was made from the cannula of the PCPS system. After this procedure, the left leg of the juvenile patient was rescued. |
14,052 | Cardiac disease and cognitive impairment: a systematic review. | Cognitive impairment in cardiac patients may interfere with disease management. This review describes studies examining specific cognitive impairments in cardiac patients and studies that investigate the link between echocardiographic and cognitive measures. Executive function impairments were frequently reported in different patient groups. Also, lower cardiac output and worse left ventricular diastolic function are linked to executive function deficits. In cardiac patients, special attention should be paid to these executive function impairments in view of their role in disease management and independent living. Interventions that stimulate executive function should be encouraged and integrated in cardiac treatment protocols. |
14,053 | Minimally-invasive video-assisted coronary-artery bypass grafting. | In general, surgeries currently tend to be less invasive and cardiac surgery has started to follow this trend.</AbstractText>To evaluate the evolution of one hundred patients undergoing minimally-invasive coronary artery bypass grafting.</AbstractText>Access to the heart was attained through a small; 6-cm thoracotomy, located in the 4th left intercostal space, starting at the nipple. Through the same intercostal space, 3 cm after the primary incision, a 6.5-mm optical device was inserted at 30º. Where the saphenous vein was used, the pericardium was opened above the aorta and the latter was partially clamped with a systolic pressure of 80 mmHg, with the proximal anastomosis being carried out in the conventional manner. The distal anastomoses were carried out in the conventional manner. The procedure was performed off-pump using single lung ventilation.</AbstractText>The mean age was 63.9 ± 10.66 years. Sixty-eight (68%) patients were males. Fifty-three (53%) were in functional class III or IV. Left ventricular function was normal in fifty-three (53%) patients. Forty-two (42%) had undergone previous angioplasty. A total of 153 anastomoses were performed, ranging from 1 to 3. The average ventilation time was 4.06 ± 4.08 hours. Seventeen (17%) patients had atrial fibrillation and eight (8%) had pneumonia. There were two deaths in this series.</AbstractText>Revascularization was safe with low mortality and morbidity. With the advent of new devices, this surgery may have a greater applicability.</AbstractText> |
14,054 | Selective site pacing from the right ventricular mid-septum. Follow-up of lead performance and procedure technique. | Pacing from the right ventricular (RV) apex is associated with adverse effects such as heart failure and atrial fibrillation. We attempted pacing from the RV mid-septum, which is theoretically a more physiological pacing site. A total of 172 consecutive patients with indications for permanent pacemaker implantation were studied. A screw-in lead and a curved stylet were used for lead positioning on the RV mid-septum. Pacemaker indices were evaluated at implantation and one year later. As an electrocardiographic parameter, QRS duration was measured in lead II. These data were compared to those of 66 patients subjected to conventional RV apical pacing. Lead placement was successful in all patients of RV mid-septal pacing. There were no technical problems during or after the procedure. The cumulative percentage of ventricular pacing at one year postimplantation was 85 ± 24 % in the SSP group. Sensing, pacing threshold, and lead impedance in the SSP group remained clinically stable over one year. When these measurements were compared between the SSP and AP groups, the pacing threshold and the lead impedance at one year postimplantation in the SSP group were higher (P < 0.05) and lower (P < 0.01), respectively, than those of the AP group. The mean QRS duration was markedly shorter (123 ± 16 versus 150 ± 18 msec, P < 0.0001). Selective site pacing from the RV mid-septum is feasible and results in less conduction delay compared to conventional RV apical pacing, and its procedure seems to be more physiological in permanent pacemaker implantation. |
14,055 | Incidence and time frame of life-threatening arrhythmias in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. | Life-threatening arrhythmias may complicate the hospital course of patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). The optimal duration of electrocardiographic monitoring in such patients is not well established. We aimed to determine the incidence and the time of occurrence of life-threatening arrhythmias in STEMI patients undergoing PPCI.</AbstractText>Data of 382 consecutive patients with STEMI undergoing PPCI were analysed regarding the occurrence of ventricular fibrillation (VF), sustained ventricular tachycardia (sVT) or bradycardia necessitating temporary or permanent pacing.</AbstractText>Of these patients, 55% had inferior STEMI, 41% anterior and 4% lateral STEMI. The infarct-related arteries were the right in 41%, the left anterior descending in 41%, the left circumflex in 16%, the left main stem in 1% and a vein graft in <1%. During hospitalisation, 27 (7.0%) patients developed 29 life-threatening arrhythmias (incidence 7.6%): 19 episodes occurred during PPCI (VF n = 11, bradycardia n = 8), 9 episodes during the first 24 hours after PPCI (VF n = 7, sVT n = 2), and 1 sVT episode in a hypokalemic patient on the 4th post-procedural day. A total of 17 patients (4.5%) died within the first 30 days, and 3 of these died during the PPCI procedure.</AbstractText>Life-threatening arrhythmias occur in a considerable proportion of STEMI patients undergoing PPCI during hospitalisation. Most of these arrhythmias occur during the PPCI procedure. Post-procedural life-threatening arrhythmias are virtually limited to the first 24 hours after PPCI. Thus, routine electrocardiographic monitoring beyond the first 24 hours after PPCI might not be required in most patients with uncomplicated STEMI.</AbstractText> |
14,056 | Effect of oxidative stress on ventricular arrhythmia in rabbits with adriamycin-induced cardiomyopathy. | The purpose of the present study was to examine the effects of oxidative stress on ventricular arrhythmias in rabbits with adriamycin-induced cardiomyopathy and the relationship between oxidative stress and ventricular arrhythmia. Forty Japanese white rabbits were randomly divided into four groups (n=10 in each): control group, metoprolol (a selective β1 receptor blocker) group, carvedilol (a nonselective β blocker/α-1 blocker) group and adriamycin group. Models of adriamycin-induced cardiomyopathy were established by intravenously injecting adriamycin hydrochloride (1 mg/kg) to rabbits via the auri-edge vein twice a week for 8 weeks in the adriamycin, metoprolol and carvedilol groups. Rabbits in the control group were given equal volume of saline through the auri-edge vein. Rabbits in the metoprolol and carvedilol groups were then intragastrically administrated metoprolol (5 mg/kg/d) and carvedilol (5 mg/kg/d) respectively for 2 months, while those in the adriamycin and control groups were treated with equal volume of saline in the same manner as in the metroprolol and carvedilol groups. Left ventricular end diastolic diameter (LVEDd) and left ventricular ejection fraction (LVEF) were measured by echocardiography. Plasma levels of N-terminal pro B-type natriuretic peptide (NT-proBNP), malondialdehyde (MAD) and superoxide dismutase (SOD) were detected. The left ventricular wedge preparations were perfused with Tyrode's solution. The transmural electrocardiogram, transmural action potentials from epicardium (Epi) and endocardium (Endo), transmural repolarization dispersion (TDR) were recorded, and the incidences of triggered activity and ventricular arrhythmias were obtained at rapid cycle lengths. The results showed that TDR and the serum MDA and NT-proBNP levels were increased, and LVEF and the serum SOD level decreased in the adriamycin group compared with the control group. The incidences of triggered activity and ventricular arrhythmia were significantly higher in the adriamycin group than those in the control group (P<0.05). In the carvedilol group as compared with the adriamycin group, the serum SOD level and the LVEF were substantially increased; the TDR, and the serum MDA and NT-proBNP levels were significantly decreased; the incidences of triggered activity and ventricular arrhythmia were obviously reduced (P<0.05). There were no significant differences in the levels of MDA and SOD, LVEF, TDR and the incidences of triggered activity and ventricular arrhythmia between the adriamycin group and the metoprolol group. It was concluded that carvedilol may inhibit triggered activity and ventricular arrhythmias in rabbit with adriamycin-induced cardiomyopathy, which is related to the decrease in oxygen free radials. |
14,057 | TNF-α blockade improves early post-resuscitation survival and hemodynamics in a swine model of ischemic ventricular fibrillation. | Inflammatory cytokines have been implicated in the pathophysiology of post cardiac arrest syndrome, including myocardial dysfunction and hypotension, often leading to multi-organ system dysfunction and death. We hypothesized that administration of infliximab after return of spontaneous circulation (ROSC) would ameliorate hypotension and myocardial dysfunction and prolong survival.</AbstractText>Domestic swine were anesthetized and instrumented. Balloon occlusion of the LAD coronary artery just distal to the first septal perforator was performed and VF followed spontaneously in all animals. After 7 min, chest compressions, defibrillation, and standard ACLS resuscitation was performed. Animals achieving ROSC (N=32) were randomized to receive infliximab (5 mg/kg, n=16) or vehicle (250 mL normal saline, n=16) immediately post-ROSC and survival and hemodynamics were monitored for 3 h.</AbstractText>There were no differences in prearrest hemodynamic variables, TNF-α levels, or resuscitation variables between groups. Both groups demonstrated a time dependent decline in mean arterial pressure (MAP) and stroke work (SW) post-ROSC with a nadir at 1 h followed by recovery over hours 2 and 3. This decline was blunted in infliximab-treated swine (1-h between group difference in MAP 21 mm Hg, 95% CI 3-38 mm Hg and SW 6.7 gm-m, 95% CI 0.4-13 at 1 h). Left ventricular systolic dp/dt fell in the vehicle group (-437 mm Hg/s, 95% CI -183 to -690) but did not in the infliximab group. Tau rose only in the vehicle group (44 ms, 95% CI 1-87). Short-term survival was higher in the infliximab group (Kaplan-Meier p=0.022).</AbstractText>Blockade of TNF-α in the immediate post-ROSC period improved survival and hemodynamic parameters in this swine model of ischemic VF.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
14,058 | Assessment of exit block following pulmonary vein isolation: far-field capture masquerading as entrance without exit block. | Complete electrical isolation of pulmonary veins (PVs) remains the cornerstone of ablation therapy for atrial fibrillation. Entrance block without exit block has been reported to occur in 40% of the patients. Far-field capture (FFC) can occur during pacing from the superior PVs to assess exit block, and this may appear as persistent conduction from PV to left atrium (LA).</AbstractText>To facilitate accurate assessment of exit block.</AbstractText>Twenty consecutive patients with symptomatic atrial fibrillation referred for ablation were included in the study. Once PV isolation (entrance block) was confirmed, pacing from all the bipoles on the Lasso catheter was used to assess exit block by using a pacing stimulus of 10 mA at 2 ms. Evidence for PV capture without conduction to LA was necessary to prove exit block. If conduction to LA was noticed, pacing output was decreased until there was PV capture without conduction to LA or no PV capture was noted to assess for far-field capture in both the upper PVs.</AbstractText>All 20 patients underwent successful isolation (entrance block) of all 76 (4 left common PV) veins: mean age 58 ± 9 years; paroxysmal atrial fibrillation 40%; hypertension 70%, diabetes mellitus 30%, coronary artery disease 15%; left ventricular ejection fraction 55% ± 10%; LA size 42 ± 11 mm. Despite entrance block, exit block was absent in only 16% of the PVs, suggesting persistent PV to LA conduction. FFC of LA appendage was noted in 38% of the left superior PVs. FFC of the superior vena cava was noted in 30% of the right superior PVs. The mean pacing threshold for FFC was 7 ± 4 mA. Decreasing pacing output until only PV capture (loss of FFC) is noted was essential to confirm true exit block.</AbstractText>FFC of LA appendage or superior vena cava can masquerade as persistent PV to LA conduction. A careful assessment for PV capture at decreasing pacing output is essential to exclude FFC.</AbstractText>Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,059 | Shen-fu injection reduces postresuscitation myocardial dysfunction in a porcine model of cardiac arrest by modulating apoptosis. | Shen-Fu injection (SFI) following cardiac arrest exhibits cardioprotective effects, but its effect on myocardial dysfunction, a critical issue following resuscitation, is unclear. This study sought to examine whether SFI reduces postresuscitation myocardial dysfunction in a porcine model of cardiac arrest by modulating apoptosis. After 8 min of untreated ventricular fibrillation and 2 min of basic life support, 24 pigs were randomized divided into three groups, which received central venous injection of either Shen-Fu (SFI group; 1.0 mL/kg), epinephrine (EP group; 0.02 mg/kg), or saline (SA group). After successful return of spontaneous circulation (ROSC), hemodynamic status and blood samples were obtained at 0, 30, 120, and 360 min after ROSC. Surviving pigs were killed at 24 h after ROSC, and the hearts were removed for analysis by electron microscopy, Western blotting, quantitative real-time polymerase chain reaction, and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) assay. Compared with the EP and SA groups, animals treated with SFI had improved left ventricular function (P < 0.05), lower troponin T levels (P < 0.01), and increased tissue perfusion and oxygen metabolism (P < 0.05). Shen-Fu injection was associated with a reduction in (i) Bcl-2, Bax, and caspase 3 protein expression (P < 0.05); (ii) caspase 3 mRNA upregulation; and (iii) apoptosis, compared with the EP and SA groups. Caspase 3-mediated apoptosis occurs following myocardial injury after cardiopulmonary resuscitation in pigs. Shen-Fu injection decreased myocardial injury; improved myocardial ultrastructure; inhibited Bcl-2, Bax, and caspase 3 expression; and reduced myocardial apoptosis. Therefore, SFI could significantly attenuate postresuscitation myocardial dysfunction by modulating apoptosis. |
14,060 | Energy status of pig donor organs after ischemia is independent of donor type. | Literature is controversial whether organs from living donors have a better graft function than brain dead (BD) and non-heart-beating donor organs. Success of transplantation has been correlated with high-energy phosphate (HEP) contents of the graft.</AbstractText>HEP contents in heart, liver, kidney, and pancreas from living, BD, and donation after cardiac death in a pig model (n=6 per donor type) were evaluated systematically. BD was induced under general anesthesia by inflating a balloon in the epidural space. Ten hours after confirmation, organs were retrieved. Cardiac arrest was induced by 9V direct current. After 10min of ventricular fibrillation without cardiac output, mechanical and medical reanimation was performed for 30min before organ retrieval. In living donors, organs were explanted immediately. Freeze-clamped biopsies were taken before perfusion with Celsior solution (heart) or University of Wisconsin solution (abdominal organs) in BD and living donors or with Histidine-Tryptophan-Ketoglutaric solution (all organs) in non-heart-beating donors, after perfusion, and after cold ischemia (4h for heart, 6h for liver and pancreas, and 12h for kidney). HEPs (adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, and phosphocreatine), xanthine, and hypoxanthine were measured by high-performance liquid chromatography. Energy charge and adenosine triphosphate-to-adenosine diphosphate ratio were calculated.</AbstractText>After ischemia, organs from different donor types showed no difference in energy status. In all organs, a decrease of HEP and an increase in hypoxanthine contents were observed during perfusion and ischemia, irrespective of the donor type.</AbstractText>Organs from BD or non-heart-beating donors do not differ from living donor organs in their energy status after average tolerable ischemia.</AbstractText>Copyright © 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,061 | Common variation in the NOS1AP gene is associated with drug-induced QT prolongation and ventricular arrhythmia. | This study sought to determine whether variations in NOS1AP affect drug-induced long QT syndrome (LQTS).</AbstractText>Use of antiarrhythmic drugs is limited by the high incidence of serious adverse events including QT prolongation and torsades de pointes. NOS1AP gene variants play a role in modulating QT intervals in healthy subjects and severity of presentation in LQTS.</AbstractText>This study carried out an association study using 167 single nucleotide polymorphisms (SNP) spanning the NOS1AP gene in 58 Caucasian patients experiencing drug-induced LQTS (dLQTS) and 87 Caucasian controls from the DARE (Drug-Induced Arrhythmia Risk Evaluation) study.</AbstractText>The rs10800397 SNP was significantly associated with dLQTS (odds ratio [OR]: 3.3, 99.95% confidence interval [CI]: 1.0 to 10.8, p = 3.7 × 10(-4)). The associations were more pronounced in the subgroup of amiodarone users, in which 3 SNPs, including rs10800397, were significantly associated (most significant SNP: rs10919035: OR: 5.5, 99.95% CI: 1.1 to 27.9, p = 3.0 × 10(-4)). We genotyped rs10919035 in an independent replication cohort of 28 amiodarone dLQTS cases versus 173 control subjects (meta-analysis of both studies: OR: 2.81, 99.95% CI: 1.62 to 4.89, p = 2.4 × 10(-4)). Analysis of corrected QT interval among 74 control subjects from our dataset showed a similar pattern of significance over the gene region as the case-control analysis. This pattern was confirmed in 1,480 control subjects from the BRIGHT (British Genetics of Hypertension Study) cohort (top SNP from DARE: rs12734991 in meta-analysis: increase in corrected QT interval per C allele: 9.1 ± 3.2 ms, p = 1.7 × 10(-4)).</AbstractText>These results provide the first demonstration that common variations in the NOS1AP gene are associated with a significant increase in the risk of dLQTS. This study suggests that common variations in the NOS1AP gene may have relevance for future pharmacogenomic applications in clinical practice permitting safer prescription of drugs for vulnerable patients.</AbstractText>Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,062 | [Cardiac arrest caused by coronary arterial vasospasm]. | Coronary arterial vasospasm may be associated with acute myocardial infarction, ventricular tachycardia or fibrillation as well as sudden death. Two case reports describing coronary vasospasm leading to ST-segment elevation and cardiac arrest are presented. Coronary arteriography revealed an occlusion that disappeared after injection of nitroglycerine. Both patients were treated with calcium antagonists and a cardioverter defibrillator (ICD) was implanted. One year after the ICD implantation no tachyarrhythmias had been registered. |
14,063 | Prevalence, clinical phenotype, and outcomes associated with normal B-type natriuretic peptide levels in heart failure with preserved ejection fraction. | B-type natriuretic peptide (BNP) is used widely to exclude heart failure (HF) in patients with dyspnea. However, most studies of BNP have focused on diagnosing HF with reduced ejection fraction (EF). The aim of this study was to test the hypothesis that a normal BNP level (≤100 pg/ml) is relatively common in HF with preserved EF (HFpEF), a heterogenous disorder commonly associated with obesity. A total of 159 consecutive patients enrolled in the Northwestern University HFpEF Program were prospectively studied. All subjects had symptomatic HF with EF >50% and elevated pulmonary capillary wedge pressure. BNP was tested at baseline in all subjects. Clinical characteristics, echocardiographic parameters, invasive hemodynamics, and outcomes were compared among patients with HFpEF with normal (≤100 pg/ml) versus elevated (>100 pg/ml) BNP. Of the 159 patients with HFpEF, 46 (29%) had BNP ≤100 pg/ml. Subjects with normal BNP were younger, were more often women, had higher rates of obesity and higher body mass index, and less commonly had chronic kidney disease and atrial fibrillation. EFs and pulmonary capillary wedge pressures were similar in the normal and elevated BNP groups (62 ± 7% vs 61 ± 7%, p = 0.67, and 25 ± 8 vs 27 ± 9 mm Hg, p = 0.42, respectively). Elevated BNP was associated with enlarged left atrial volume, worse diastolic function, abnormal right ventricular structure and function, and worse outcomes (e.g., adjusted hazard ratio for HF hospitalization 4.0, 95% confidence interval 1.6 to 9.7, p = 0.003). In conclusion, normal BNP levels were present in 29% of symptomatic outpatients with HFpEF who had elevated pulmonary capillary wedge pressures, and although BNP is useful as a prognostic marker in HFpEF, normal BNP does not exclude the outpatient diagnosis of HFpEF. |
14,064 | Mechanisms underlying the autonomic modulation of ventricular fibrillation initiation--tentative prophylactic properties of vagus nerve stimulation on malignant arrhythmias in heart failure. | Classical physiology teaches that vagal post-ganglionic nerves modulate the heart via acetylcholine acting at muscarinic receptors, whilst it is accepted that vagus nerve stimulation (VNS) slows heart rate, atrioventricular conduction and decreases atrial contraction; there is continued controversy as to whether the vagus has any significant direct effect on ventricular performance. Despite this, there is a significant body of evidence from experimental and clinical studies, demonstrating that the vagus nerve has an anti-arrhythmic action, protecting against induced and spontaneously occurring ventricular arrhythmias. Over 100 years ago Einbrodt first demonstrated that direct cervical VNS significantly increased the threshold for experimentally induced ventricular fibrillation. A large body of evidence has subsequently been collected supporting the existence of an anti-arrhythmic effect of the vagus on the ventricle. The development of prognostic indicators of heart rate variability and baroreceptor reflex sensitivity--measures of parasympathetic tone and reflex activation respectively--and the more recent interest in chronic VNS therapy are a direct consequence of the earlier experimental studies. Despite this, mechanisms underlying the anti-arrhythmic actions of the vagus nerve have not been fully characterised and are not well understood. This review summarises historical and recently published data to highlight the importance of this powerful endogenous protective phenomenon. |
14,065 | Statins in heart failure: the paradox between large randomized clinical trials and real life. | To assess the relationship between statins and prognosis in ischemic and nonischemic patients with heart failure (HF) in a real-life cohort followed up for a long period.</AbstractText>This prospective study included 960 patients with HF with preserved or depressed left ventricular ejection fraction (LVEF), irrespective of HF etiology, who were referred to the HF clinic of a university hospital between August 1, 2001, and December 31, 2008. The patients were followed up for a maximum of 9.1 years (median, 3.7 years), and survival in ischemic and nonischemic patients was determined.</AbstractText>Median age was 69 years, and median LVEF was 31%. Of the 960 patients, 532 (55.4%) had ischemic HF etiology, and most received angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (846; 88.1%) and β-blockers (776; 80.8%). Patients with HF of ischemic origin were more often treated with statins (P<.001). During follow-up, 440 patients (45.8%) died. Statin therapy was associated with significantly improved survival (hazard ratio, 0.45 [95% confidence interval, 0.37-0.54]; P<.001). After adjustment for HF prognostic factors (age, sex, cholesterol level, New York Heart Association class, HF etiology, LVEF, body mass index, HF duration, atrial fibrillation, implantable cardioverter-defibrillator therapy, and medicines), statins remained significantly associated with lower mortality risk in both ischemic (P=.007) and nonischemic (P=.002) patients.</AbstractText>In contrast to results of large randomized trials, statins were independently and significantly associated with lower mortality risk in our real-life HF cohort, including patients with nonischemic HF etiology.</AbstractText>Copyright © 2012 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,066 | Induction of atrial fibrillation with adenosine during a transesophageal electrophysiology study to risk stratify a patient with asymptomatic ventricular preexcitation. | An asymptomatic adolescent male athlete was incidentally found to have ventricular preexcitation on electrocardiogram during a sports preparticipation physical. A transesophageal electrophysiology study (TEEPS) was performed after an exercise stress test failed to delineate the patient's risk of sudden cardiac death. The TEEPS was favored in this case over a transvenous electrophysiology study due to reduced invasiveness. The goal of the TEEPS was to place the patient into atrial fibrillation (AFib) and evaluate the shortest preexcited RR interval during AFib, thereby assessing the risk of his accessory pathway. Conventional pacing modalities were unable to induce AFib. During atrial burst pacing, adenosine was then administered, which successfully induced AFib. This case highlights adenosine's potential to induce atrial fibrillation during transesophageal electrophysiology studies when atrial pacing alone was unable to do so. |
14,067 | QT interval disturbances in elderly residents of long-term care facilities. | The QT interval reflects the total duration of ventricular myocardial repolarization. Disturbed QT--either prolonged or shortened--is associated with arrhythmia and is life-threatening.</AbstractText>To investigate an elderly population for disturbed QT interval.</AbstractText>We conducted a cross-sectional study on residents of long-term care wards in a geriatric hospital. Excluded were those with pacemaker, atrial fibrillation or bundle branch block. The standard 12 lead and lead 2 electrocardiograms in the patients' files were used for the evaluation of QT interval.</AbstractText>We screened the ECGs of 178 residents. QTc prolongation based on the mean 12 ECG leads was detected in 48 (28%), while 45 (25%) had prolonged QTc based on lead L2. Factors associated with QT prolongation were male gender, chronic renal failure and diabetes mellitus. Short QT was found in 7 residents (4%) and was not related to any parameter.</AbstractText>About one-third of the elderly long-term care residents in our study had QT disturbances. Such a considerable number warrants close QT interval follow-up in predisposed patients.</AbstractText> |
14,068 | A proton leak current through the cardiac sodium channel is linked to mixed arrhythmia and the dilated cardiomyopathy phenotype. | Cardiac Na(+) channels encoded by the SCN5A gene are essential for initiating heart beats and maintaining a regular heart rhythm. Mutations in these channels have recently been associated with atrial fibrillation, ventricular arrhythmias, conduction disorders, and dilated cardiomyopathy (DCM).We investigated a young male patient with a mixed phenotype composed of documented conduction disorder, atrial flutter, and ventricular tachycardia associated with DCM. Further family screening revealed DCM in the patient's mother and sister and in three of the mother's sisters. Because of the complex clinical phenotypes, we screened SCN5A and identified a novel mutation, R219H, which is located on a highly conserved region on the fourth helix of the voltage sensor domain of Na(v)1.5. Three family members with DCM carried the R219H mutation.The wild-type (WT) and mutant Na(+) channels were expressed in a heterologous expression system, and intracellular pH (pHi) was measured using a pH-sensitive electrode. The biophysical characterization of the mutant channel revealed an unexpected selective proton leak with no effect on its biophysical properties. The H(+) leak through the mutated Na(v)1.5 channel was not related to the Na(+) permeation pathway but occurred through an alternative pore, most probably a proton wire on the voltage sensor domain.We propose that acidification of cardiac myocytes and/or downstream events may cause the DCM phenotype and other electrical problems in affected family members. The identification of this clinically significant H(+) leak may lead to the development of more targeted treatments. |
14,069 | Infusion of 4°C normal saline can improve the neurological outcome in a porcine model of cardiac arrest. | This study sought to investigate induction of therapeutic hypothermia using ice-cold intravenous fluid after cardiopulmonary resuscitation (CPR). The effects on temperature, hemodynamics, cognitive performance and the accompanying neurohistopathological changes, and apoptosis were assessed.</AbstractText>Fourteen piglets had 4 minutes of untreated ventricular fibrillation, followed by CPR. The animals in which spontaneous circulation was restored were randomly assigned to two groups: the hypothermia group (n = 7) was given an infusion of 4°C cold normal saline solution 30 mL/kg at an infusion rate of 1.33 mL/kg/min, followed by 10 mL/kg/h to 4 hours after restoration of spontaneous circulation; the control group (n = 7) was given the same infusion at room temperature. Variables were measured repeatedly until 4 hours after restoration of spontaneous circulation. Neurocognitive performance was evaluated 24 hours after CPR. Then animals were killed and the brains were removed for histopathology at 24 hours after restoration of spontaneous circulation. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling method was used for apoptosis evaluation.</AbstractText>Compared with the control group, the core temperature of the hypothermia group was significantly decreased (p < 0.01). The cerebral performance categories at 24 hours after restoration of spontaneous circulation in the hypothermia group were better than that in the control group (p < 0.05). The percentage of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling-positive cells in the cortex and dentate gyrus of the hippocampus were significantly reduced in the hypothermia group compared with the control group at 24 hours after restoration of spontaneous circulation. By observation of transmission electron microscopy, the neuron damages were significantly reduced in hypothermia group.</AbstractText>4°C normal saline solution is a safe and effective method to reduce brain damages and prevent apoptotic cell death after cardiac arrest.</AbstractText> |
14,070 | Left ventricular diastolic dysfunction in atrial fibrillation: predictors and relation with symptom severity. | Left ventricular diastolic dysfunction (LVDD) is common in the general population, but its prevalence in atrial fibrillation (AF), predictors for LVDD in AF and the association between LVDD and AF-related symptom severity has not been well studied.</AbstractText>In 124 consecutive patients (mean age 61 ± 11years, 60% male) with paroxysmal (n = 70) or persistent AF (n = 54) referred for AF catheter ablation, LVDD was evaluated according to current guidelines using transthoracic echocardiography. AF-related symptom severity was quantified using the European Heart Rhythm Association score.</AbstractText>LVDD was present in 46 patients (37%). In uni- and multivariable regression analysis, age (OR 1.068 per year, 95% CI 1.023-1.115, P = 0.003) and persistent AF (OR 2.427 vs. paroxysmal AF, 95% CI 1.112-5.3, P = 0.026) were associated with LVDD. LVDD was found in 11% with mild AF symptoms (n = 27) as opposed to 44% in patients with moderate-severe AF symptoms (n = 97, P = 0.002). Thus, the OR for moderate-severe AF symptoms was 6.368 (1.797-22.568, P = 0.004) in the presence of LVDD.</AbstractText>LVDD (1) occurs frequently in AF, (2) is associated with advancing age and AF progression and (3) is correlated with symptom severity in AF.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,071 | [Brain natriuretic peptide (BNP) level predicts long term ventricular arrhythmias in patients with moderate to severe left ventricular dysfunction]. | Brain natriuretic peptide (BNP) is a powerful predictor of mortality in patients with left ventricular dysfunction. Since malignant ventricular arrhythmias such as sustained ventricular tachycardia (VT) and ventricular fibrillation (VF) are a major cause of death among those patients, we postulated that BNP levels can predict their long-term occurrence.</AbstractText>To study the association between malignant ventricular arrhythmias and BNP level over a long term follow-up.</AbstractText>We prospectively followed 94 patients with ischemic heart disease and left ventricular dysfunction, all implanted with an implantable cardioverter defibrillator (ICD). BNP level was measured at baseline and ICD interrogation and clinical status were recorded at 6 months intervals for a median of 3.5 years.</AbstractText>Patients with BNP levels in the highest quartile experienced significantly more arrhythmic events than those at the lower three quartiles (OR 2.2, 95% C.I 1.2-4.2). In a multivariate analysis only BNP level predicted arrhythmic events. Among patients implanted for primary prevention of sudden cardiac death, BNP at the lowest quartile significantly predicted low event rate.</AbstractText>While high BNP level is predictive of malignant ventricular arrhythmias, low levels among patients implanted for primary prevention can identify a low risk subgroup for which the ICD might be of borderline therapeutic benefit.</AbstractText> |
14,072 | [Sudden cardiac death and automated external defibrillators. Where we are in 2012?]. | Sudden cardiac death (SCD) is one of the major problems in the western world with approximately 70.000-100.000 SCD patients (pts) in Germany and 450.000 SCD victims in the US. SCD is not caused by a single factor but is a multifactorial problem. SCD is caused by ventricular tachyarrhythmias in approximately 90% of pts, whereas SCD is caused by bradyarrhythmias in 5-10%. In 50% of SCD victims, sudden cardiac death is the first manifestation of a heart disease. There is general agreement that early defibrillation with automated external defibrillators (AED) is an effective tool to treat pts with ventricular fibrillation. Nevertheless, further stragies on cardiopulmonary resuscitation and AED therapy are necessary to improve survival of patients with cardiac arrest. |
14,073 | Pulsatile abdominal mass is not always leaking aneurysm! | An 80-year-old male, who presented with a history of unprovoked collapse, was found to have a visible pulsation in the central upper abdomen, which disappeared on raising his arms above his shoulder ('head and shoulder' technique). There was no tenderness noted over the pulsation. He had a ventricular demand inhibited pacemaker inserted 3 weeks ago for a significant bradycardia with atrial fibrillation. His ECG showed heart rate of 32 bpm with underlying atrial fibrillation. No pacing spikes noted. His chest x-ray confirmed displacement of pacing lead into the right subclavian vein. It caused stimulation of phrenic nerve resulting in rhythmical diaphragmatic contraction. He later had his pacemaker re-inserted with no more collapses. |
14,074 | Cardiopulmonary resuscitation and management of cardiac arrest. | The best chance of survival with a good neurological outcome after cardiac arrest is afforded by early recognition and high-quality cardiopulmonary resuscitation (CPR), early defibrillation of ventricular fibrillation (VF), and subsequent care in a specialist center. Compression-only CPR should be used by responders who are unable or unwilling to perform mouth-to-mouth ventilations. After the first defibrillator shock, further rhythm checks and defibrillation attempts should be performed after 2 min of CPR. The underlying cause of cardiac arrest can be identified and treated during CPR. Drugs have a limited effect on long-term outcomes after cardiac arrest, although epinephrine improves the success of resuscitation, and amiodarone increases the success of defibrillation for refractory VF. Supraglottic airway devices are an alternative to tracheal intubation, which should be attempted only by skilled rescuers. Care after cardiac arrest includes controlled reoxygenation, therapeutic hypothermia for comatose survivors, percutaneous coronary intervention, circulatory support, and control of blood-glucose levels and seizures. Prognostication in comatose survivors of cardiac arrest needs a careful, multimodal approach using clinical and electrophysiological assessments after at least 72 h. |
14,075 | Common variation in fatty acid genes and resuscitation from sudden cardiac arrest. | Fatty acids provide energy and structural substrates for the heart and brain and may influence resuscitation from sudden cardiac arrest (SCA). We investigated whether genetic variation in fatty acid metabolism pathways was associated with SCA survival.</AbstractText>Subjects (mean age, 67 years; 80% male, white) were out-of-hospital SCA patients found in ventricular fibrillation in King County, WA. We compared subjects who survived to hospital admission (n=664) with those who did not (n=689), and subjects who survived to hospital discharge (n=334) with those who did not (n=1019). Associations between survival and genetic variants were assessed using logistic regression adjusting for age, sex, location, time to arrival of paramedics, whether the event was witnessed, and receipt of bystander cardiopulmonary resuscitation. Within-gene permutation tests were used to correct for multiple comparisons. Variants in 5 genes were significantly associated with SCA survival. After correction for multiple comparisons, single-nucleotide polymorphisms in ACSL1 and ACSL3 were significantly associated with survival to hospital admission. Single-nucleotide polymorphisms in ACSL3, AGPAT3, MLYCD, and SLC27A6 were significantly associated with survival to hospital discharge.</AbstractText>Our findings indicate that variants in genes important in fatty acid metabolism are associated with SCA survival in this population.</AbstractText> |
14,076 | Efficacy of landiolol hydrochloride for atrial fibrillation after open heart surgery. | It is important to establish effective treatment for postoperative atrial fibrillation (AF), the most common complication after cardiac surgery. We evaluated the efficacy and safety of landiolol hydrochloride for rhythm conversion in patients with postoperative AF. Among 134 patients who developed new-onset AF after open heart surgery between 2007 and 2009, 69 patients who received landiolol hydrochloride for treatment of postoperative AF were enrolled. The AF conversion rate, the percentage of patients with 20 % reduction of the ventricular rate, and the factors related to successful treatment were evaluated. Then, the landiolol group was compared with 65 patients who had postoperative AF and did not receive landiolol hydrochloride. Landiolol hydrochloride was the first-line treatment in 46 patients and the only therapy in 26 patients. Reversion to sinus rhythm was achieved in 51 patients, while the conversion rate in patients without landiolol hydrochloride was only 56.8 % (p < 0.05). A 20 % reduction of the ventricular rate was achieved more frequently in the landiolol group. Although landiolol hydrochloride was highly effective in patients who had undergone off-pump coronary artery bypass grafting, patients with cardiopulmonary bypass did not respond as well. The heart rate was reduced from 130 ± 26 to 81 ± 12 (p < 0.05) after landiolol administration, while blood pressure did not decrease significantly. Landiolol hydrochloride was effective for conversion of postoperative AF. This ultra-short-acting β-blocker is a safe first-line treatment for postoperative AF after open heart surgery, and is most effective in patients who have undergone off-pump coronary artery bypass grafting. |
14,077 | Clinical characteristics and prevalence of early repolarization associated with ventricular arrhythmias following acute ST-elevation myocardial infarction. | Early repolarization (ER) on a 12-lead electrocardiogram has recently been associated with ventricular tachyarrhythmias (VTAs) in patients without structural heart disease and in patients with healed myocardial infarction (MI). An association between ER and VTAs in the setting of acute ST-segment elevation MI (STEMI) has not been explored. In a single-center retrospective case-control design, 50 patients with STEMI complicated by VTAs (cases), defined as ventricular fibrillation, sustained ventricular tachycardia, or nonsustained ventricular tachycardia within 72 hours of the index hospitalization, were matched for age and gender with 50 subjects with STEMI without VTAs (controls). Electrocardiograms obtained an average of 1 year before STEMI were analyzed for ER pattern, defined as notching or slurring of the terminal QRS complex or J-point elevation >0.1 mV above baseline in ≥ 2 contiguous leads. A higher prevalence of ER was associated with VTAs overall in cases compared to controls (26% vs 4%, p = 0.01) and localized to anterior (16% vs 0%) and inferior (14% vs 2%, p = 0.07) leads but not lateral limb leads. Notching (10% vs 2%, p = 0.1) and J-point elevation (16% vs 0%) were more common in cases. Slurring was uncommon. ER was associated with VTAs (odds ratio [OR] 6.5, 95% confidence interval [CI] 1.5 to 28.8, p = 0.01), even after adjustment for creatine kinase-MB (OR 9.2, 95% CI 1.6 to 53.4, p = 0.01) and ejection fraction (OR 5.7, 95% CI 1.2 to 27.1, p = 0.03). In conclusion, ER is associated with VTAs in patients with STEMI even after adjustment for left ventricular ejection fraction or creatine kinas-MB levels. Larger prospective studies exploring potential associations and mechanisms of ventricular arrhythmogenesis with ER pattern are needed. |
14,078 | Factors influencing left atrial volume in treated hypertension. | Left atrial (LA) enlargement has been documented to occur in hypertension (HT), and has been an index for evaluating the diastolic function of the left ventricle. Enlargement of the LA is one of the vital factors that induce heart failure and atrial fibrillation (AF) in patients with HT.</AbstractText>130 treated hypertensive patients were enrolled. All recruits participated in an echocardiogram, electrocardiogram, a routine blood examination including brain natriuretic peptide (BNP), and physical examinations.</AbstractText>Left ventricular mass (LVM) indexed to height(2.7) had a significant positive correlation with left atrial volume index (LAVI) (p<0.0001), as well as natural logarithm BNP (p<0.001). Blood pressure levels were not associated with LAVI, neither body mass index nor age. LAVI had a positive correlation with factors involving the left ventricle volume, LVM, and right ventricle systolic pressure (RVSP) (r=0.687, p<0.0001). The parameters of LV diastolic function were positively but weakly associated with LA size. In the subgroup of LAVI, the evidence of paroxysmal atrial fibrillation (PAF): LAVI<32 ml/m(2) had no PAF, whereas the incidence of PAF was 7.5%, 11.4%, and 15.2%, respectively in the LAVI>32 ml/m(2) group. Of anti-hypertension drugs, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers had a tendency to reduce LAVI; however, there was no statistical significance within the groups.</AbstractText>Left ventricular volume and mass are independent factors affecting LAVI in treated HT. The incidence of PAF is associated with LA size. In patients with treated HT, LA size may be a useful surrogate marker for monitoring the effectiveness of medical therapy and occurrence of AF.</AbstractText>Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
14,079 | Transcatheter versus surgical treatment for aortic stenosis: patient selection and early outcome. | To describe short-term clinical and echocardiography outcomes in patients undergoing transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). To explore patient selection criteria for treatment with TAVI.</AbstractText>TAVI patients (n = 45) were matched to SAVR patients (n = 45) with respect to age within ± 10 years, sex and systolic left ventricular function.</AbstractText>TAVI patients were older, 82 ± 8 versus 78 ± 5 years (p = 0.005) and they had higher logEuroSCORE, 16 ± 11% versus 8 ± 4% (p = 0.001). There were no significant differences in 30 days mortality, stroke and myocardial infarction. TAVI patients received less erythrocyte (53% vs. 78%, p = 0.03) and thrombocyte (7% vs. 27%, p = 0.02) transfusions. Postoperative atrial fibrillation was less common (18% vs. 60%, p = 0.001) in the TAVI group. Paravalvular regurgitation was more common in TAVI patients (87% vs. 0%, p = 0.001) and 27% had access site complications. Aortic transvalvular velocity was 2.3 ± 0.4 m/s versus 2.6 ± 0.5 m/s (p = 0.002) and mean valve pressure gradient was 12 ± 4 mmHg versus 15 ± 5 mmHg (p = 0.01) in the TAVI and SAVR groups, respectively. Twenty-nine (64%) of the TAVI patients had logEuroSCORE = 15%.</AbstractText>Both TAVI and SAVR have good short term clinical outcome with excellent hemodynamic result. In clinical practice, factors other than high logEuroSCORE play an important role in patient selection for TAVI.</AbstractText> |
14,080 | Amplitude Changes during Ventricular Fibrillation: A Mechanistic Insight. | Clinically in ventricular fibrillation (VF), ECG amplitude, and frequency decrease as ischemia progresses and predict defibrillation success. In vitro ECG amplitude declines without ischemia, independent of VF frequencies. This study examines the contribution of cellular electrical activity and global organization to ECG amplitude changes during VF.</AbstractText>Rabbit hearts were Langendorff-perfused (40 mL/min, Tyrode's solution) and loaded with RH237. During VF, ECG, and epicardial optical action potentials were recorded (photodiode array; 256 sites, 15 mm × 15 mm). After 60 s of VF, perfusion was either maintained, global ischemia produced by low-flow (6 mL/min), or solution [K(+)](o) raised to 8 mM. Peak-to-peak amplitude was determined for all signals. During VF, in control, ECG amplitude decreased to a steady-state (∼57% baseline), whereas in low-flow steady-state was not reached with the amplitude continuing to fall to 33% of baseline by 600 s. Optically, LV amplitude declined more than RV, reaching significance in control (LV vs. RV; 33 ± 5 vs. 63 ± 8%, p < 0.01). During VF in 8 mM [K(+)](o), amplitude changes were more complex; ECG amplitude increased with time (105 ± 13%), whilst LV amplitude decreased (60 ± 15%, p < 0.001). Microelectrode studies showed amplitude reduction in control and 8 mM [K(+)](o) (to ∼79 and ∼93% baseline, respectively). Evaluation of electrical coordination by cross-correlation of optical signals showed as VF progressed coordination reduced in control (baseline 0.36 ± 0.02 to 0.28 ± 0.003, p < 0.01), maintained in low-flow (0.41 ± 0.03 to 0.37 ± 0.005, p = NS) and increased in 8 mM [K(+)](o) (0.36 ± 0.02 to 0.53 ± 0.08, p < 0.05).</AbstractText>ECG amplitude decline in VF is due to a combination of decreased systolic activation at the cellular level and increased desynchronization of inter-cellular electrical activity.</AbstractText> |
14,081 | Same-day discharge after catheter ablation for routine arrhythmias: an initial experience. | Same-day discharge (SDD) in the setting of catheter ablation (CA) is not widely applied. We present our experience concerning SDD in a selected population of patients who underwent CA; the outcome was evaluated in terms of feasibility and safety.</AbstractText>401 CA procedures were performed at our institution between January 2008 and December 2009 in 379 patients (65±16 years, 221 men). 336 CA procedures (84%) were considered eligible for SDD, after the exclusion of ventricular arrhythmias, atrial fibrillation, atypical atrial flutter, AV node ablation as well as procedures involving an arterial or transseptal access. Subsequently, a number of clinical and organizational exclusion criteria were applied.</AbstractText>223 patients were actually discharged on the same day of CA (56% of 401 overall CA procedures): 114 atrial flutter (AFL) and 109 supraventricular tachycardia. Many patients were excluded before CA due to a limited availability of the day-hospital facility; this occurred more frequently in the year 2008 than 2009 (45 vs. 2, P=0.0001); in the year 2009 the rate of total CA procedures which underwent SDD was of 68%. Overall, three groin hematomas occurred, all in patients ablated for AFL. Two of them were recognized during the postablation</AbstractText>SDD can be safely performed in most patients undergoing CA for routine arrhythmias. This may result in a significant impact on daily practice in terms of both organizational improvement and subjective benefit for the patients.</AbstractText> |
14,082 | A strategy to achieve CRT response in permanent atrial fibrillation without obligatory atrioventricular node ablation. | Cardiac resynchronization therapy (CRT) is an established method in patients with severe heart failure and wide QRS configuration, particularly during sinus rhythm (SR). In CRT patients with permanent atrial fibrillation (AF), there is no general consensus regarding the need for atrioventricular node (AVN) ablation. The aim of this study was to evaluate the benefit of CRT in permanent AF with and without AVN ablation.</AbstractText>New York Heart Association classification, QRS duration, and echocardiographic parameters were assessed before and after CRT with a follow-up of 12 ± 3 months. Two hundred thirty patients in SR and 46 patients with permanent AF of 2.1 ± 0.5 years duration were studied. AVN ablation was performed only in AF patients with insufficient pharmacological rate control evidenced by ≤80 % ventricular stimulation.</AbstractText>Fifteen AF patients underwent AVN ablation. Biventricular pacing comparably improved functional status, left ventricular ejection fraction, and left ventricular end-diastolic dimensions in all treated groups. Biventricular stimulation percentage was 10% lower in pharmacologically treated AF patients over 1 year as compared to patients in SR and to AF patients undergoing AVN ablation, which did not affect outcome in this patient population.</AbstractText>In patients with permanent AF and CRT, an AVN ablation strategy might not be strictly required in all patients.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
14,083 | Atrial Fibrillation and Brugada Syndrome. | Since its first description in 1992, the Brugada syndrome (BrS) has attracted significant attention from the cardiology community because of its association with malignant ventricular arrhythmias and sudden cardiac death. Supraventricular tachyarrhythmias in BrS represent a unique and seemingly higher-risk clinical subgroup of patients with BrS. Atrial fibrillation represents the most common supraventricular arrhythmia in patients with BrS, with average ranges reported in the literature of 20% to 40%. This article summarizes the current literature regarding the patient with BrS with atrial fibrillation and discusses the management of these clinically challenging and potentially higher-risk individuals. |
14,084 | A Patient with a 40% Ejection Fraction Undergoes Atrioventricular Nodal Ablation for the Management of Atrial Fibrillation with Rapid Ventricular Rates. What Type of Device Should He Receive? | Patients with symptomatic atrial fibrillation not amenable to pharmacologic therapy or catheter ablation may be appropriate candidates for atrioventricular nodal (AVN) ablation and placement of a permanent pacemaker. The question arises as to whether to implant a right ventricular (RV)-only pacing device or a cardiac resynchronization therapy (CRT) device. This article examines 2 similar cases of patients presenting for AVN ablation who received RV-only pacing devices but had different clinical outcomes. This article discusses existing guidelines and studies that can help clinicians address the challenging question of whether an initial implant of a CRT pacing device is warranted in such patients. |
14,085 | Initial clinical predictors of significant coronary lesions after resuscitation from cardiac arrest. | Urgent coronary angiography following cardiac arrest is an important consideration as part of a therapeutic hypothermia/postresuscitation care bundle. Few data exist to guide the selection of patients who should receive postarrest angiography. This investigation sought to evaluate patient-level variables on initial postarrest presentation and their association with significant coronary lesions on subsequent angiography. Clinical and angiographic data were collected on consecutive postarrest patients from July 2007 to April 2012 who underwent coronary angiography during hospitalization. Univariate and multivariable analyses were performed to determine the relationship between patient characteristics, clinical data, and the outcome measure, defined as the presence of at least one coronary lesion with >75% stenosis. Of 527 cardiac arrest patients, 267 achieved return of spontaneous circulation; 106 of these initial survivors received coronary angiography. This cohort had a mean age of 58.1±13.5 years and a survival to discharge of 73/106 (69%), with therapeutic hypothermia utilized in 79/106 (75%) patients. Significant coronary lesions were found on angiography in 68/106 (64%) patients. Multivariable adjusted analysis demonstrated that significant lesions were associated with a prior known history of coronary disease and/or prior myocardial infarction (odds ratio [OR] 6.2, 95% confidence interval [CI] 1.6-24.4, p=0.009), and with initial rhythm of ventricular fibrillation/ventricular tachycardia (OR 2.9, 95% CI 1.1-7.7, p=0.033), but not with hypertension, tobacco use, age, or initial troponin measurements. Prior known history of coronary disease and a shockable arrest rhythm were associated with significant coronary lesions on subsequent angiography. Normal initial troponin values and younger age did not exclude clinically relevant lesions postarrest. |
14,086 | Serum uric acid levels are associated with atrial fibrillation in patients with ischemic heart failure. | We evaluated the association between serum uric acid (SUA) and atrial fibrillation (AF) in patients with chronic heart failure (HF). Totally, 363 patients with chronic HF were included in the study. Of all, 78 patients had AF and 285 patients were in normal sinus rhythm. Serum uric acid was significantly increased in patients with AF compared with patients in normal sinus rhythm (P < .05). Comparing patients with AF and normal sinus rhythm, we found that age was significantly higher in patients group with AF. Echocardiographic parameters including ejection fraction, left atrial diameter, left ventricle end-diastolic diameter, and left ventricle end-diastolic volume were also significantly higher in patients with AF compared with patients in normal sinus rhythm. We have shown that patients with AF have significantly higher SUA and this was independently associated with AF in patients with ischemic HF. |
14,087 | Sustained ventricular tachycardia and ventricular fibrillation complicating non-ST-segment-elevation acute coronary syndromes. | Ventricular arrhythmias remain a lethal complication of acute coronary syndromes (ACS). However, the incidence and prognosis of sustained ventricular tachycardia/ventricular fibrillation (VT/VF) in contemporary non-ST-segment-elevation (NSTE) ACS populations are not well described.</AbstractText>We examined the incidence of VT/VF and subsequent survival among 9211 patients enrolled in the Early Glycoprotein IIb/IIIa Inhibition in NSTE ACS (EARLY ACS) trial. The cumulative incidence of VT/VF was 1.5% (n=141); 0.6% (n=55) had VT/VF ≤48 hours after enrollment, and 0.9% (n=86) had VT/VF >48 hours after enrollment. Patients with VT/VF more frequently had prior heart failure, an ejection fraction <30%, and triple-vessel coronary artery disease. Predictors of sustained VT/VF were similar regardless of the timing of VT/VF (≤48 versus >48 hours). Patients with VT/VF ≤48 hours after enrollment had higher 30-day mortality than those who did not have VT/VF ≤48 hours (13.0% versus 2.2%; adjusted odds ratio, 6.73; 95% confidence interval, 2.68-16.9). The increased risk of death associated with VT/VF ≤48 hours persisted at 1 year. The risk of mortality, relative to patients without VT/VF, was greater for patients with VT/VF >48 hours (hazard ratio, 20.70; 95% confidence interval, 15.39-27.85) than for those with earlier VT/VF (hazard ratio, 7.45; 95% confidence interval, 4.60-12.08; P=0.0003). The frequency of arrhythmic death was higher in patients with VT/VF than in those without VT/VF (26.4% versus 6.9%).</AbstractText>Sustained VT/VF is infrequent after NSTE ACS but is as likely to occur after 48 hours as within the first 48 hours. The marked increase in all-cause death among NSTE ACS patients with both early and late sustained VT/VF raises important considerations for aggressive monitoring beyond 48 hours and interventions to prevent arrhythmic death in these patients.</AbstractText>URL: http://www.clinicaltrials.gov. Unique identifier: NCT00089895.</AbstractText> |
14,088 | The use of ω-3 poly-unsaturated fatty acids in heart failure: a preferential role in patients with diabetes. | To review the evidence for a beneficial effect of ω-3 PUFAs in heart failure (HF) and its co-morbidities, their possible preferential effect in diabetes and the potential mechanism for their benefit.</AbstractText>We summarize the clinical studies which investigated the use of ω-3 PUFAs in patients with HF with an emphasis on diabetes. We briefly summarize the evidence for an effect of ω-3 PUFAs in patients with coronary artery disease (CAD), atrial fibrillation (AF) and ventricular arrhythmias. We also discuss the proposed mechanisms of ω-3 PUFA action in cardiovascular diseases.</AbstractText>While there is emerging evidence for a beneficial effect of ω-3 PUFA supplementation in patients with HF, the evidence for other indications have been variable and conflicting. In HF patients with diabetes, ω-3 PUFAs may have a preferential therapeutic benefit. Randomized controlled trials did not show considerable beneficial effects of ω-3 PUFAs in other conditions such as CAD and AF. In a diabetic and insulin-resistant state, ω-3 PUFAs bind to the G-protein coupled receptor, GPR120, resulting in reduced cytokine production from inflammatory macrophages and improved signaling in adipocytes, leading to a reduction in insulin resistance.</AbstractText>There is promising evidence showing that use of ω-3 PUFA supplementation improves clinical outcomes of HF patients with diabetes. Further clinical trials are needed in this regard.</AbstractText> |
14,089 | The use of left ventricular assist devices in the treatment of class IV heart failure patients: what the non-heart failure specialist needs to know. | The New York Heart Association class IV heart failure patient represents a very sick patient population with a poor 6-month survival rate. With appropriate selection and timing, left ventricular assist devices can provide improved outcomes while these patients are supported for bridge to heart transplant or destination therapy. As the number of heart failure patients supported by left ventricular assist devices increases, physicians will need to be familiar with postoperative chronic issues (such as right ventricular failure, infection, hypertension, atrial fibrillation, bleeding, and thromboembolic events) that can affect the function of these devices. |
14,090 | The relationship of asymptomatic intracranial artery stenosis and Framingham stroke risk profile in a Northern Chinese industrial city. | Intracranial artery stenosis may be the most frequent cause of ischemic stroke in the world. Early detection of asymptomatic intracranial artery stenosis may allow for therapeutic intervention. Most elements of the Framingham stroke risk profile (FSRP) are also risk factors for intracranial artery stenosis. Thus, the FSRP might play a role in detecting asymptomatic intracranial artery stenosis.</AbstractText>To investigate the relationship between the FSRP and asymptomatic intracranial artery stenosis.</AbstractText>A sample of 5852 subjects (age >40 years) was selected from the KaiLuan study. All participants received transcranial Doppler ultrasound examinations to detect the presence and quantify the severity of intracranial arterial stenosis. Demographic and clinical variables were investigated at the time of examination. Binary logistic regression analyses was performed to determine the odds ratio of FSRP components to asymptomatic intracranial stenosis before and after adjusted for gender, body mass index (BMI), and total cholesterol (TC).</AbstractText>The subjects with intracranial artery stenosis were older than those without (68·2 versus 64·9), and the systolic blood pressure was higher in those with intracranial artery stenosis (146·86 versus 136·39). Among intracranial artery stenosis subjects, 77·5% had hypertension, 26·1% had diabetes, 8·9% had left ventricular hypertrophy, and 4·8% had atrial fibrillation. Logistic regression analyses revealed that age, systolic blood pressure, diabetes, atrial fibrillation, and left ventricular hypertrophy were risk factors for intracranial artery stenosis. The incidence of asymptomatic intracranial artery stenosis correlated with increasing FSRP scores. The odds ratios of intracranial artery stenosis from the lowest to the highest FSRP quartiles were as follows: 1 (reference group), 1·77 (95% CI: 1·23-2·56), 2·84 (95% CI: 2·02-3·98), 5·65 (95% CI: 4·03-7·93).</AbstractText>FSRP plays an important role in detecting asymptomatic intracranial artery stenosis.</AbstractText> |
14,091 | From a wide to a narrow QRS tachycardia and back. What is the mechanism? | A 40-year-old man developed a near syncope during exercise due to a wide complex tachycardia with periods of changing RR intervals accompanied by changes in QRS morphology. The differential diagnosis of this electrocardiographic pattern is discussed. |
14,092 | Extra- and intracellular recordings from the avjunction: discerning the mechanisms for irregular ventricular responses during supraventricular arrhythmias. | There has been a long-standing controversy regarding the mechanism(s) to explain the irregular ventricular response during atrial tachycardia (AT) or atrial fibrillation (AF) and where the site of block, if any, resides in the atrioventricular (AV) junction.</AbstractText>We studied 12 Langendorff preparations perfused with modified Tyrode's solution containing 5-10 mM diacetyl monoxime which suppressed contractility but allowed the use of intracellular action potential (AP) recordings. Octapolar catheters (2-mm rings, 2-mm spacing) were secured along the tricuspid annulus from the apex to the base of the triangle of Koch and along the anterior limbus of the fossa ovalis to record extracellular, slow pathway, fast pathway, His bundle (Hb) and AV nodal (AVN) extracellular potentials as well as intracellular action potentials.</AbstractText>AT or AF induced by rapid atrial pacing showed a variety of irregular responses due to: (1) Wenckebach conduction showing decrement within the AVN and progressive diminution of extracellular AVN potentials (n = 5); (2) repetitive concealed conduction proximal to the AVN (n = 3); (3) ectopic beats arising within the AVN (n = 2); (4) ectopic beats arising at the Hb (n = 2).</AbstractText>In this experimental preparation, extracellular and intracellular recordings provided presumptive evidence for the mechanisms causing the irregularities of the ventricular response such as repetitive concealed conduction, enhanced automaticity or electrotonically triggered activity. Also more definitive determinations of the site of block in the AV junction were also obtained.</AbstractText> |
14,093 | The occurrence of atrial fibrillation in former top-level handball players above the age of 50. | Cardiac adaptation to sports activity in endurance athletes is considerably different from that in power athletes. The effects of a high-level team sport like handball, one of the most popular sports in the world, performed at a younger age, on cardiac rhythm in individuals above the age of 50 have not been investigated to date.</AbstractText>Thirty-three former top-level handball players from the first German league (6 former world champions and numerous Olympians) (57.5 +/- 5.5 y) joined our screening programme for former athletes and underwent electrocardiography, echocardiography and spiroergometry. Data were compared to 24 sedentary healthy controls.</AbstractText>Ten of the 33 athletes suffered from atrial fibrillation (AF). Left ventricular diameter was 53.68 +/- 4.88 mm in the athletes group and 50.58 +/- 4.12 mm in the healthy controls. Analysing the subgroups of handball players ('AF group' and 'non-AF group'), spiroergometry showed oxygen consumption at the anaerobic threshold of 27.54 +/- 6.77 ml/kg/min in the AF group and 31.24 +/- 10.33 ml/kg/min in the non-AF group (P = 0.228). Absolute left atrial diameter was 44.34 +/- 4.41 mm in the AF group (non-AF group 38.94 +/- 3.77 mm, P < 0.001) (healthy controls 37.54 +/- 4.34 mm, compared with all athletes P = 0.015). In all individuals left ventricular wall thickness was within normal limits. However, myocardial walls were thicker in the AF group (11.28 +/- 1.83 mm) than in the non-AF group (9.44 +/- 1.26 mm, P = 0.002). Athletes in the AF group (187.6 +/- 6.42 cm) were significantly taller than in the non-AF group (180.91 +/- 7.31 cm, P = 0.018).</AbstractText>Not only endurance training, but also sports activity with a relevant static component, like team handball, might predispose for AF above the age of 50. LA size, height and myocardial wall thickness seem to affect the risk of developing AF. More data in non-endurance sports are mandatory to confirm this hypothesis.</AbstractText> |
14,094 | Optimal ablation strategies for different types of ventricular tachycardias. | Ablation strategies for almost all types of ventricular tachycardias have now been established. The optimal ablation strategy for ventricular tachycardia is determined by the site of origin and the electrophysiological mechanisms. Electrocardiograms, an understanding of the common sites of basic disease, and identification of the scar site using imaging modalities might be helpful for predicting the originating location. Electrophysiological activation mapping is the gold standard for identification of the ventricular tachycardia substrate. However, when activation mapping of scar-related ventricular tachycardias is not possible, substrate mapping might be performed to identify isolated diastolic potentials. Substrates are commonly located in the endocardium, but transvenous or subxiphoidal intrapericardial approaches can be used to map epicardial substrates. Unusual types of ventricular tachycardia might require special strategies, such as transcoronary ethanol or intramural needle ablation. For idiopathic ventricular tachycardias, ablation might be a first-line therapy because of its high efficacy and very low risk of complications. However, the recurrence rate of scar-related ventricular tachycardias remains considerable, and ablation remains an adjunctive therapy to medical therapy and implantable cardioverter-defibrillators. When incessant ventricular tachycardia or fibrillation requiring defibrillator therapy (electrical storm) is refractory to antiarrhythmic drugs, neuraxial modulation, including sedation, might be the next option before catheter ablation is attempted. |
14,095 | A validated prediction tool for initial survivors of in-hospital cardiac arrest. | Accurate estimation of favorable neurological survival after in-hospital cardiac arrest could provide critical information for physicians, patients, and families.</AbstractText>Within the Get With the Guidelines-Resuscitation registry, we identified 42,957 patients from 551 hospitals admitted between January 2000 and October 2009 who were successfully resuscitated from an in-hospital cardiac arrest. A simple prediction tool for favorable neurological survival in patients successfully resuscitated from an in-hospital cardiac arrest was developed using multivariate logistic regression, with two-thirds of the sample randomly selected as the derivation cohort and one-third as the validation cohort. Favorable neurological status was defined as the absence of severe neurological deficits (cerebral performance category score of ≤2).</AbstractText>Rates of favorable neurological survival were similar in the derivation cohort (7052 patients [24.6%]) and validation cohort (3510 patients [24.5%]). Eleven variables were associated with favorable neurological survival: younger age, initial cardiac arrest rhythm of ventricular fibrillation or pulseless ventricular tachycardia with a defibrillation time of 2 minutes or less, baseline neurological status without disability, arrest location in a monitored unit, shorter duration of resuscitation, and absence of mechanical ventilation, renal insufficiency, hepatic insufficiency, sepsis, malignant disease, and hypotension prior to the arrest. The model had excellent discrimination (C statistic of 0.80 for both the derivation and validation cohorts) and calibration. The prediction tool demonstrated the ability to identify patients across a wide range of rates of favorable neurological survival: patients in the top decile had a 70.7% probability of this outcome, whereas patients in the bottom decile had a 2.8% probability.</AbstractText>Among successfully resuscitated patients with an in-hospital cardiac arrest, a simple, bedside prediction tool provides robust estimates of the probability of favorable neurological survival. This tool permits accurate prognostication after cardiac arrest for physicians, patients, and families.</AbstractText> |
14,096 | Interventricular heterogeneity as a substrate for arrhythmogenesis of decoupled mitochondria during ischemia in the whole heart. | Myocardial ischemia results in metabolic changes, which collapse the mitochondrial network, that increase the vulnerability of the heart to ventricular fibrillation (VF). It has been demonstrated at the single cell level that uncoupling the mitochondria using carbonyl cyanide p-(tri-fluoromethoxy)phenyl-hydrazone (FCCP) at low concentrations can be cardioprotective. The aim of our study was to investigate the effect of FCCP on arrhythmogenesis during ischemia in the whole rabbit heart. We performed optical mapping of isolated rabbit hearts (n = 33) during control and 20 min of global ischemia and reperfusion, both with and without pretreatment with the mitochondrial uncoupler FCCP at 100, 50, or 30 nM. No hearts went into VF during ischemia under the control condition, with or without the electromechanical uncoupler blebbistatin. We found that pretreatment with 100 (n = 4) and 50 (n = 6) nM FCCP, with or without blebbistatin, leads to VF during ischemia in all hearts, whereas pretreatment with 30 nM of FCCP led to three out of eight hearts going into VF during ischemia. We demonstrated that 30 nM of FCCP significantly increased interventricular (but not intraventricular) action potential duration and conduction velocity heterogeneity in the heart during ischemia, thus providing the substrate for VF. We showed that wavebreaks during VF occurred between the right and left ventricular junction. We also demonstrated that no VF occurred in the heart pretreated with 10 μM glibenclamide, which is known to abolish interventricular heterogeneity. Our results indicate that low concentrations of FCCP, although cardioprotective at the single cell level, are arrhythmogenic at the whole heart level. This is due to the fact that FCCP induces different electrophysiological changes to the right and left ventricle, thus increasing interventricular heterogeneity and providing the substrate for VF. |
14,097 | Renin-angiotensin system inhibitors can suppress atrial fibrillation recurrence after encircling ipsilateral pulmonary vein isolation in patients with a non-dilated left atrium. | The purpose of this study was to investigate whether the effects of renin-angiotensin system inhibitors (RASIs) after encircling ipsilateral pulmonary veins isolation (EIPVsI) for atrial fibrillation (AF) differed between patients with non-dilated and dilated left atria.</AbstractText>We retrospectively studied 292 consecutive patients (mean age=61±11 years, 75% males) who underwent successful EIPVsI for paroxysmal or persistent AF. RASIs' effects were compared between the patients with a non-dilated left atrium of <40 mm (n=178) and dilated left atrium of ≥40 mm (n=114).</AbstractText>During a mean follow-up period of 18.9±12.7 months, AF recurred in 38 (21.4%) and 45 (39.5%) patients with non-dilated and dilated left atria, respectively. A multivariate Cox proportional analysis revealed that treatment with RASIs (hazard ratio (HR) 0.30, 95% confidence interval (CI) =0.13-0.66, p=0.003), the duration of AF (HR 1.08/year, 95% CI=1.01-1.16, p=0.03), a history of hypertension (HR 2.86, 95% CI=1.21-6.85, p=0.02) and the left ventricular ejection fraction (HR 0.54/10%↑, 95% CI=0.34-0.87, p=0.01) were associated with AF recurrences in patients with a non-dilated left atrium. On the other hand, only the duration of AF (HR 1.11/year, 95% CI=1.01-1.21, p=0.03) was associated with AF recurrences in those with a dilated LA, and RASIs had no effect on AF recurrences (p=0.65).</AbstractText>RASIs suppressed AF recurrences after EIPVsI only in patients with a non-dilated left atrium.</AbstractText> |
14,098 | Prognostic significance of reciprocal ST-segment depression in patients with acute STEMI undergoing immediate invasive intervention. | Reciprocal changes are frequent in patients with acute ST-segment elevation myocardial infarction (STEMI). However, their prognostic significance is not clear in patients undergoing immediate invasive intervention.</AbstractText>We retrospectively examined 165 consecutive patients with STEMI receiving immediate invasive intervention. The first electrocardiography taken in the emergency department was analyzed. Patients were assigned to 2 groups: with a reciprocal change (group I, n = 100) and without a reciprocal change (group II, n = 65).</AbstractText>Electrocardiographs revealed that more anterolateral and inferior STEMI occurred in group I and more anterior STEMI occurred in group II. In the emergency department, group I had lower systolic and diastolic blood pressures, higher ventricular tachycardia and fibrillation rates, and higher cardiopulmonary resuscitation rates than did group II. Upon admission, peak troponin I levels were significantly higher in group I, and more group I patients required intra-aortic balloon pumping support. This unstable hemodynamic condition in group I patients was reflected by their higher in-hospital mortality rate. Multivariate analysis showed that age (odds ratio [OR], 1.103; 95% confidence interval [CI], 1.022-1.190; P = .012), Killip class (OR, 2.785; 95% CI, 1.049-7.400; P = .040), and reciprocal change (OR, 9.553; 95% CI, 1.146-79.608; P = .037) remained as independent predictors of in-hospital mortality. Actuarial freedom from all-cause mortality was worse in group I (P = .046).</AbstractText>The data suggest that patients with STEMI with reciprocal electrocardiographic changes have unstable hemodynamic status and poorer outcomes. Further prospective studies using a larger patient population are needed.</AbstractText>Copyright © 2012 Elsevier Inc. All rights reserved.</CopyrightInformation> |
14,099 | Cardiac arrest with refractory ventricular fibrillation: a successful resuscitation using extracorporeal membrane oxygenation. | Extracorporeal membrane oxygenation (ECMO) is a form of a mechanical cardiopulmonary life-support system and an adjunct to prolonged cardiac resuscitation. The ECMO results in good outcomes for patients with in-hospital cardiac arrest. We present a case of a 52-year-old man with out-of-hospital cardiac arrest caused by refractory ventricular fibrillation. The patient was referred to our emergency department with suspected acute coronary syndrome. Cardiac arrest with ventricular fibrillation was refractory to conventional cardiopulmonary resuscitation. In this case, the ECMO–cardiopulmonary resuscitation provided cardiopulmonary life support for out-of-hospital cardiac arrest, achieving a sustained return of spontaneous circulation that allowed prompt percutaneous coronary intervention and a good recovery. |
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