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11,300 | Role of NADPH oxidase and xanthine oxidase in mediating inducible VT/VF and triggered activity in a canine model of myocardial ischemia. | Ventricular tachycardia or fibrillation (VT/VF) of focal origin due to triggered activity (TA) from delayed afterdepolarizations (DADs) is reproducibly inducible after anterior coronary artery occlusion. Both VT/VF and TA can be blocked by reducing reactive oxygen species (ROS). We tested the hypothesis that inhibition of NADPH oxidase and xanthine oxidase would block VT/VF.</AbstractText>69 dogs received apocynin (APO), 4 mg/kg intraveneously (IV), oxypurinol (OXY), 4 mg/kg IV, or both APO and OXY (BOTH) agents, or saline 3 h after coronary occlusion. Endocardium from ischemic sites (3-D mapping) was sampled for Rac1 (GTP-binding protein in membrane NADPH oxidase) activation or standard microelectrode techniques. Results (mean±SE, * p<0.05): VT/VF originating from ischemic zones was blocked by APO in 6/10 *, OXY in 4/9 *, BOTH in 5/8 * or saline in 1/27; 11/16 VT/VFs blocked were focal. In isolated myocardium, TA was blocked by APO (10(-6) M) or OXY (10(-8) M). Rac1 levels in ischemic endocardium were decreased by APO or OXY.</AbstractText>APO and OXY suppressed focal VT/VF due to DADs, but the combination of the drugs was not more effective than either alone. Both drugs inhibited ischemic Rac1 with inhibition by OXY suggesting ROS-induced ROS. The inability to totally prevent VT/VF suggests that other mechanisms also contribute to ischemic VT.</AbstractText> |
11,301 | Right ventricular free wall dyskinesis in the setting of left ventricular non compaction: a case report. | Left ventricular non compaction is a relatively rare congenital disorder characterized by prominent trabeculations and intertrabecular recesses with the potential for thromboembolism, arrhythmias, and sudden cardiac death as adverse effects. Echocardiography has traditionally been employed as the primary mode of imaging; however, with the advent of cardiac magnetic resonance as a more precise imaging technique, the disorder known as left ventricle non compaction is becoming more broadly defined with increasing recognition of right ventricle (RV) involvement.</AbstractText>This report describes a 52-year-old Caucasian female with new onset atrial fibrillation with an unusual finding of left ventricular non compaction and right ventricular dysfunction on transthoracic echocardiogram with preserved left ventricular ejection fraction. Cardiac magnetic resonance imaging demonstrated a disproportionately affected right ventricle, with apical free wall dyskinesis.</AbstractText>This case illustrates the unique occurrence of left ventricular non compaction with preserved ejection fraction alongside RV free wall dyskinesis and RV systolic dysfunction. The significance of this is yet unknown given the paucity of existing literature. This report serves to highlight the vast heterogeneity within left ventricular non compaction as we are better able to delineate this disorder using increasingly sophisticated imaging techniques.</AbstractText> |
11,302 | Risk for ventricular fibrillation in peripartum cardiomyopathy with severely reduced left ventricular function-value of the wearable cardioverter/defibrillator. | The true incidence of life-threatening ventricular tachyarrhythmic events and the risk of sudden cardiac death in the early stage of peripartum cardiomyopathy (PPCM) are still unknown. We aimed to assess the usefulness of the wearable cardioverter/defibrillator (WCD) to bridge a potential risk for life-threatening arrhythmic events in patients with early PPCM, severely reduced left ventricular ejection fraction (LVEF) and symptoms of heart failure.</AbstractText>Twelve consecutively admitted women with PPCM were included in this single-centre, prospective observational study between September 2012 and September 2013. Patients with LVEF ≤35% were considered to use the WCD for 3 months or even 6 months when considered necessary for LVEF recovery. Nine of the 12 women had a severely reduced LVEF (mean 18.3%) at the time of study enrollment; seven women received a WCD, while two patients refused to wear a WCD. During a median WCD follow-up of 81 days (range 25-345 days), we observed a total of four events of ventricular fibrillation with appropriate and successful WCD shocks in three of the seven women receiving a WCD. No syncope or sudden arrhythmic deaths occurred in women not using the WCD during a median follow-up of 12 months (range 5-15 months). All women showed impressive improvement of LVEF during follow-up.</AbstractText>PPCM patients with severely reduced LVEF have an elevated risk for ventricular tachyarrhythmias early after diagnosis. Therefore, use of the WCD should be considered in all women with early-stage PPCM and severely reduced LVEF during the first 6 months after initiation of heart failure therapy.</AbstractText>© 2014 The Authors European Journal of Heart Failure © 2014 European Society of Cardiology.</CopyrightInformation> |
11,303 | The prognostic significance of atrial fibrillation in heart failure with a preserved and reduced left ventricular function: insights from a meta-analysis. | The prognostic significance of atrial fibrillation (AF) in patients with heart failure remains inconclusive.</AbstractText>To perform a meta-analysis of the published data to study the prognostic significance of AF in heart failure patients and to determine whether this relates to the presence of preserved or reduced left ventricular systolic function.</AbstractText>We searched the MEDLINE (from inception to May 2014) supplemented by manual searches of references of relevant retrieved articles. Randomized clinic trials and observational studies were included with hazard ratios (HRs) of AF for mortality in chronic heart failure patients. The search strategy yielded 20 studies that met our eligibility criteria. A total of 61 240 AF patients in 152 306 heart failure participants were included, with 39 879 deaths occurring during follow-up. Pooled HRs for AF in mortality in heart failure was 1.17 (95% confidence intervals: 1.11-1.23) using random-effect model (I(2)  = 44.5%). There was a significant difference of combined HRs between heart failure patients with preserved and reduced left ventricular ejection fraction (LVEF) in separate analysis. Sensitivity analysis supported the consistence of the results.</AbstractText>Atrial fibrillation is significantly associated with increased mortality in heart failure patients. The prognostic significance of AF may be different between heart failure with preserved and reduced LVEF, and AF is associated with poorer prognosis in heart failure patients with preserved LVEF.</AbstractText>© 2014 The Authors European Journal of Heart Failure © 2014 European Society of Cardiology.</CopyrightInformation> |
11,304 | Successful cardiac resuscitation with extracorporeal membrane oxygenation in the setting of persistent ventricular fibrillation: a case report. | Extracorporeal membrane oxygenation (ECMO) technology is a viable option for short-term support in the setting of acute cardiac ischemia. To supplement cardiopulmonary resuscitation (CPR) in select patients, ECMO is used successfully for witnessed in hospital cardiac arrest. In the setting of an acute myocardial infarction (MI), bridging to a revascularization procedure is important in improving overall survival.</AbstractText>We describe the first known case of a 56-year-old Caucasian male with an anterior ST elevation myocardial infarction (STEMI) who underwent percutaneous coronary intervention (PCI) in which the entire procedure was carried out with the patient being in persistent ventricular fibrillation (VF) resistant to defibrillation on ECMO support. Subsequent to revascularization, the patient's cardiac rhythm converted back to sinus rhythm with a single defibrillation shock with excellent neurologic recovery.</AbstractText>Our case highlights the importance of early initiation of ECMO during PCI in achieving both improved cardiac and neurological outcomes during an acute coronary syndrome (ACS).</AbstractText> |
11,305 | Quantitative evaluation of atrial radio frequency ablation using intracardiac shear-wave elastography. | Radio frequency catheter ablation (RFCA) is a well-established clinical procedure for the treatment of atrial fibrillation (AF) but suffers from a low single-procedure success rate. Recurrence of AF is most likely attributable to discontinuous or nontransmural ablation lesions. Yet, despite this urgent clinical need, there is no clinically available imaging modality that can reliably map the lesion transmural extent in real time. In this study, the authors demonstrated the feasibility of shear-wave elastography (SWE) to map quantitatively the stiffness of RFCA-induced thermal lesions in cardiac tissues in vitro and in vivo using an intracardiac transducer array.</AbstractText>SWE was first validated in ex vivo porcine ventricular samples (N = 5). Both B-mode imaging and SWE were performed on normal cardiac tissue before and after RFCA. Areas of the lesions were determined by tissue color change with gross pathology and compared against the SWE stiffness maps. SWE was then performed in vivo in three sheep (N = 3). First, the stiffness of normal atrial tissues was assessed quantitatively as well as its variation during the cardiac cycle. SWE was then performed in atrial tissue after RFCA.</AbstractText>A large increase in stiffness was observed in ablated ex vivo regions (average shear modulus across samples in normal tissue: 22 ± 5 kPa, average shear-wave speed (ct): 4.5 ± 0.4 m s(-1) and in determined ablated zones: 99 ± 17 kPa, average ct: 9.0 ± 0.5 m s(-1) for a mean shear modulus increase ratio of 4.5 ± 0.9). In vivo, a threefold increase of the shear modulus was measured in the ablated regions, and the lesion extension was clearly visible on the stiffness maps.</AbstractText>By its quantitative and real-time capabilities, Intracardiac SWE is a promising intraoperative imaging technique for the evaluation of thermal ablation during RFCA.</AbstractText> |
11,306 | Frequency and predictors of stroke after acute myocardial infarction: specific aspects of in-hospital and postdischarge events. | Stroke is a serious complication after acute myocardial infarction (AMI) and is closely associated with decreased survival. This study aimed to investigate the frequency, characteristics, and factors associated with in-hospital and postdischarge stroke in patients with AMI.</AbstractText>Eight thousand four hundred eighty-five consecutive patients admitted to a cardiology intensive care unit for AMI, between January 2001 and July 2010. Stroke/transient ischemic attack were collected during 1-year follow-up.</AbstractText>One hundred twenty-three in-hospital strokes were recorded: 65 (52.8%) occurred on the first day after admission for AMI, and 108 (87%) within the first 5 days. One hundred six patients (86.2%-incidence rate 1.25%) experienced in-hospital ischemic stroke, and 14 patients (11.4%-incidence rate 0.16%) were diagnosed with an in-hospital hemorrhagic stroke. In-hospital ischemic stroke subtypes according to the Trial of Org 10 172 in Acute Stroke Treatment (TOAST) classification showed that only 2 types of stroke were identified more frequently. As expected, the leading subtype of in-hospital ischemic stroke was cardioembolic stroke (n=64, 60%), the second was stroke of undetermined pathogenesis (n=38, 36%). After multivariable backward regression analysis, female sex, previous transient ischemic attack (TIA)/stroke, new-onset atrial fibrillation, left ventricular ejection fraction (odds ratio per point of left ventricular ejection fraction), and C-reactive protein were independently associated with in-hospital ischemic stroke. When antiplatelet and anticoagulation therapy within the first 48 hours was introduced into the multivariable model, we found that implementing these treatments (≥1) was an independent protective factor of in-hospital stroke. In-hospital hemorrhagic stroke was dramatically increased (5-fold) when thrombolysis was prescribed as the reperfusion treatment. However, the different parenteral anticoagulants were not predictors of risk in univariable analysis. Finally, only 45 postdischarge strokes were recorded. Postdischarge stroke subtypes showed a more heterogeneous distribution of mechanisms. The annual rate of stroke post-AMI remained stable throughout the 10-year study period.</AbstractText>The present study describes specific predictors of in-hospital and postdischarge stroke in patients with AMI. It showed a marked increase in the risk of death, both during hospitalization and in the year after AMI. After hospital discharge, stroke remains a rare event and is mostly associated with high cardiovascular risk.</AbstractText>© 2014 American Heart Association, Inc.</CopyrightInformation> |
11,307 | Circulating aldosterone and natriuretic peptides in the general community: relationship to cardiorenal and metabolic disease. | We sought to investigate the role of aldosterone as a mediator of disease and its relationship with the counter-regulatory natriuretic peptide (NP) system. We measured plasma aldosterone (n=1674; aged≥45 years old) in a random sample of the general population from Olmsted County, MN. In a multivariate logistic regression model, aldosterone analyzed as a continuous variable was associated with hypertension (odds ratio [OR]=1.75; 95% confidence interval [CI]=1.57-1.96; P<0.0001), obesity (OR=1.34; 95% CI=1.21-1.48; P<0.0001), chronic kidney disease (OR=1.39; 95% CI=1.22-1.60; P<0.0001), central obesity (OR=1.47; 95% CI=1.32-1.63; P<0.0001), metabolic syndrome (OR=1.41; 95% CI=1.26-1.58; P<0.0001), high triglycerides (OR=1.23; 95% CI=1.11-1.36; P<0.0001), concentric left ventricular hypertrophy (OR=1.22; 95% CI=1.09-1.38; P=0.0007), and atrial fibrillation (OR=1.24; 95% CI=1.01-1.53; P=0.04), after adjusting for age and sex. The associations with hypertension, central obesity, metabolic syndrome, triglycerides, and concentric left ventricular hypertrophy remained significant after further adjustment for body mass index, NPs, and renal function. Furthermore, aldosterone in the highest tertile correlated with lower NP levels and increased mortality. Importantly, most of these associations remained significant even after excluding subjects with aldosterone levels above the normal range. In conclusion, we report that aldosterone is associated with hypertension, chronic kidney disease, obesity, metabolic syndrome, concentric left ventricular hypertrophy, and lower NPs in the general community. Our data suggest that aldosterone, even within the normal range, may be a biomarker of cardiorenal and metabolic disease. Further studies are warranted to evaluate a therapeutic and preventive strategy to delay the onset and progression of disease, using mineralocorticoid antagonists or chronic NP administration in high-risk subjects identified by plasma aldosterone. |
11,308 | Evaluation of quantification methods for left arial late gadolinium enhancement based on different references in patients with atrial fibrillation. | By using late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging, we compared left atrial late gadolinium enhancement (LA-LGE) quantification methods based on different references to characterize the left atrial wall in patients with atrial fibrillation (AF). Thirty-eight patients who underwent three-dimensional LGE-CMR imaging before catheter ablation for AF were classified into three groups depending on their clinical AF type: (1) paroxysmal AF (PAF; n = 12); (2) persistent AF (PeAF; n = 16); and (3) recurrent AF after catheter ablation (RAF; n = 10). To quantify LA-LGE on LGE-CMR imaging, we used the thresholds of 2 standard deviations (2-SD), 3-SD, 4-SD, 5-SD, or 6-SD above the mean signal from the unenhanced left ventricular myocardium, and we used the full width at half maximum (FWHM) technique, which was based on the maximum signal from the mitral valve with high signal intensity. The 6-SD threshold and FWHM techniques were statistically reproducible with an intraclass correlation coefficient >0.7. On applying the FWHM technique, the normalized LA-LGE volume by LA wall area showed a significant difference between the RAF, PeAF, and PAF groups (0.22 ± 0.04, 0.16 ± 0.06, and 0.09 ± 0.03 mL/cm(2), respectively) (P < 0.05). Furthermore, most of the fibrotic scarring and low-voltage tissue on the electroanatomic map corresponded well with the extent of LA-LGE. The FWHM technique based on the mitral valve can provide a reproducible quantification of LA-LGE related to AF in the thin LA wall. |
11,309 | Long-Term Impact of Different Immunosuppressive Drugs on QT and PR Intervals in Renal Transplant Patients. | Sudden cardiac deaths due to arrhythmias are thought to be an important cause of mortality in patients with renal transplants. Exposure to immunosuppressive drugs may lead to QT or PR interval abnormalities which may consequently cause arrhythmias. Our study investigated the long term impact of four different immunosuppressive drugs on PR and corrected QT intervals (QTc) in renal transplant patients</AbstractText>The study population consisted of 98 kidney transplant recipients. Study patients were receiving immunosuppressive management with tacrolimus, cyclosporine A, everolimus or azathioprine according to the local protocols. QTc and PR intervals obtained from the most recent post-transplant electrocardiograms were compared with the pre-transplant intervals dated before the transplantation procedure.</AbstractText>Post-transplant QTc intervals had prolonged significantly in comparison to the pre-transplant QTc intervals in all groups. However, there were no significant differences between the immunosuppressive agents with regard to post-transplant QTc interval prolongation (p > 0.05). There were no significant differences between the groups with regard to the pre and post-transplant PR interval changes (p > 0.05).</AbstractText>QT interval prolongation, a marker of risk for arrhythmias and sudden death, is highly prevalent among kidney transplant patients receiving different classes of immunosuppressive drugs.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,310 | Dependency of exercise-induced T-wave alternans predictive power for the occurrence of ventricular arrhythmias from heart rate. | T-wave alternans (TWA) is a noninvasive index of risk for the occurrence of ventricular arrhythmias. It is known that TWA amplitude (TWAA) increases with heart rate (HR) but how the TWA predictive power varies with HR remains unknown. Thus, the aim of this study was to evaluate the dependency of exercise-induced TWA predictive power for the occurrence of ventricular arrhythmias from HR.</AbstractText>TWA was identified using our HR adaptive match filter in exercise ECGs from 248 patients with implanted cardiac defibrillator (ICD), of which 72 developed ventricular tachycardia and/or fibrillation during the 4 year follow-up (ICD_Cases) and 176 did not (ICD_Controls). TWA predictive power was evaluated at HRs from 80 to 120 bpm by computing the area under the receiver operating characteristic curve (AUC) obtained using the maximum TWAA (maxTWAA) and the TWAA ratio (TWAAratio; i.e., the ratio between TWAA at a specific HR and at 80 bpm).</AbstractText>TWAA increased with HR. At 80 bpm maxTWAA was lower than at 120 bpm in both ICD_Cases (22 μV vs 41 μV; P < 10(-2) ) and ICD_ Controls (16 μV vs 36 μV; P < 10(-4) ). However, only at 80 bpm ICD_Cases showed significantly higher maxTWAA than ICD_Controls (AUC = 0.6486; P = 0.0080). TWAAratio was higher in ICD_Controls than ICD_Cases for all HR but 120 bpm, and its predictive power was maximum at 115 bpm (AUC = 0.6914; P < 0.05).</AbstractText>Exercise-induced TWA predictive power for the occurrence of ventricular arrhythmias, quantified using both maxTWAA and TWAAratio, was higher at low rather than at high HR.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,311 | The effect of lidocaine and amiodarone on prevention of ventricular fibrillation in patients undergoing coronary artery bypass grafting. | Ventricular fibrillation is common after aortic declamping in patients undergoing open heart surgery. This situation has a negative impact on morbidity and mortality. The aim of this prospective study was to compare the effect of administering lidocaine versus amiodarone before aortic declamping during elective coronary bypass grafting, paying close attention to when the initial effect of amiodarone sets in.</AbstractText>In this double blind, prospective, randomized, controlled study, 86 patients who were candidates for elective coronary artery bypass grafting were recruited into three groups: group lidocaine (group L, n=29); group amiodarone (group A, n=27); and group placebo (group P, n=30). Group L patients received 1.5 mg/kg of lidocaine 2 minutes before aortic declamping and group A patients received 300 mg of amiodarone intravenously 15 minutes before release of the aortic cross clamp. The primary endpoints were the incidence of ventricular fibrillation and the number of shocks required to terminate ventricular fibrillation.</AbstractText>The frequency of ventricular fibrillation occurrence was significantly higher in group P (70%) when compared with group A (37%) and group L (38%) (P=.017). There was no statistically significant difference between the amiodarone and the lidocaine groups regarding ventricular fibrillation. However, when ventricular fibrillation occurred, the percentage of patients requiring electrical defibrillation was significantly higher in both group L and group P when compared with group A (P=.023).</AbstractText>We suggest that during coronary arterial bypass surgery, administration of an amiodarone regime before release of the aortic cross clamp, paying particular attention to the start of the initial effect of amiodarone, is no more effective than lidocaine for prevention from arrhythmia; however, amiodarone reduces the need for electrical defibrillation.</AbstractText> |
11,312 | Rate-control drugs affect variability and irregularity measures of RR intervals in patients with permanent atrial fibrillation. | Irregularity measures have been suggested as risk indicators in patients with atrial fibrillation (AF); however, it is not known to what extent they are affected by commonly used rate-control drugs. We aimed at evaluating the effect of metoprolol, carvedilol, diltiazem, and verapamil on the variability and irregularity of the ventricular response in patients with permanent AF.</AbstractText>Sixty patients with permanent AF were part of an investigator-blind cross-over study, comparing 4 rate-control drugs (diltiazem, verapamil, metoprolol, and carvedilol). We analyzed five 20-minute segments per patient: baseline and the 4 drug regimens. On every segment, heart rate (HR) variability and irregularity of RR series were computed. The variability was assessed as standard deviation, pNN20, pNN50, pNN80, and rMSSD. The irregularity was assessed by regularity index, approximate (ApEn), and sample entropy. A significantly lower HR was obtained with all drugs, the HR was lowest using the calcium channel blockers. All drugs increased the variability of ventricular response in respect to baseline (as an example, rMSSD: baseline 171 ± 47 milliseconds, carvedilol 229 ± 58 milliseconds; P < 0.05 vs. baseline, metoprolol 226 ± 66 milliseconds; P < 0.05 vs. baseline, verapamil 228 ± 84; P < 0.05 vs. baseline, diltiazem 256 ± 87 milliseconds; P < 0.05 vs. baseline and all other drugs). Only β-blockers significantly increased the irregularity of the RR series (as an example, ApEn: baseline 1.86 ± 0.13, carvedilol 1.92 ± 0.09; P < 0.05 vs. baseline, metoprolol 1.93 ± 0.08; P < 0.05 vs. baseline, verapamil 1.86 ± 0.22 ns, diltiazem 1.88 ± 0.16 ns).</AbstractText>Modification of AV node conduction by rate-control drugs increase RR variability, while only β-blockers affect irregularity.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,313 | Hydrogen inhalation during normoxic resuscitation improves neurological outcome in a rat model of cardiac arrest independently of targeted temperature management. | We have previously shown that hydrogen (H2) inhalation, begun at the start of hyperoxic cardiopulmonary resuscitation, significantly improves brain and cardiac function in a rat model of cardiac arrest. Here, we examine the effectiveness of this therapeutic approach when H2 inhalation is begun on the return of spontaneous circulation (ROSC) under normoxic conditions, either alone or in combination with targeted temperature management (TTM).</AbstractText>Rats were subjected to 6 minutes of ventricular fibrillation cardiac arrest followed by cardiopulmonary resuscitation. Five minutes after achieving ROSC, post-cardiac arrest rats were randomized into 4 groups: mechanically ventilated with 26% O2 and normothermia (control); mechanically ventilated with 26% O2, 1.3% H2, and normothermia (H2); mechanically ventilated with 26% O2 and TTM (TTM); and mechanically ventilated with 26% O2, 1.3% H2, and TTM (TTM+H2). Animal survival rate at 7 days after ROSC was 38.4% in the control group, 71.4% in the H2 and TTM groups, and 85.7% in the TTM+H2 group. Combined therapy of TTM and H2 inhalation was superior to TTM alone in terms of neurological deficit scores at 24, 48, and 72 hours after ROSC, and motor activity at 7 days after ROSC. Neuronal degeneration and microglial activation in a vulnerable brain region was suppressed by both TTM alone and H2 inhalation alone, with the combined therapy of TTM and H2 inhalation being most effective.</AbstractText>H2 inhalation was beneficial when begun after ROSC, even when delivered in the absence of hyperoxia. Combined TTM and H2 inhalation was more effective than TTM alone.</AbstractText>© 2014 American Heart Association, Inc.</CopyrightInformation> |
11,314 | Remote ischemic pre- and postconditioning improve postresuscitation myocardial and cerebral function in a rat model of cardiac arrest and resuscitation. | Cardiac arrest and resuscitation are models of whole body ischemia reperfusion injury. Postresuscitation myocardial and cerebral dysfunction are major causes of high mortality and morbidity. Remote ischemic postconditioning has been proven to provide potent protection of the heart and brain against ischemia reperfusion injury. In this study, we investigated the effects of remote ischemic postconditioning on postresuscitation myocardial and cerebral function in a rat model of cardiac arrest and resuscitation.</AbstractText>Prospective, randomized, controlled experimental study.</AbstractText>University-affiliated animal research institution.</AbstractText>Twenty-eight healthy male Sprague-Dawley rats.</AbstractText>The animals were randomized into four groups: 1) remote ischemic preconditioning initiated 40 minutes before induction of ventricular fibrillation, 2) remote ischemic postconditioning initiated coincident with the start of cardiopulmonary resuscitation, 3) remote ischemic postconditioning initiated 5 minutes after successful resuscitation, and 4) control. Remote ischemic pre- and postconditioning was induced by four cycles of 5 minutes of limb ischemia, followed by 5 minutes of reperfusion. Ventricular fibrillation was induced and untreated for 6 minutes while defibrillation was attempted after 8 minutes of cardiopulmonary resuscitation. The animals were then monitored for 4 hours and observed for an additional 68 hours after resuscitation.</AbstractText>Hemodynamic measurements and myocardial function, including cardiac output, left ventricular ejection fraction, and myocardial performance index, were measured at baseline and hourly for 4 hours after resuscitation. Postresuscitation cerebral function was evaluated by neurologic deficit score at 24-hour intervals for a total of 72 hours. Consequently, significantly better myocardial and cerebral function with a longer duration of survival were observed in the three groups treated with remote ischemic pre- and postconditioning.</AbstractText>In a rat model of cardiac arrest and resuscitation, remote ischemic pre-and postconditioning attenuated postresuscitation myocardial and cerebral dysfunction and improved the duration of survival.</AbstractText> |
11,315 | Non-invasive evaluation of the effect of metoprolol on the atrioventricular node during permanent atrial fibrillation. | During atrial fibrillation (AF), conventional electrophysiological techniques for assessment of refractory period or conduction velocity of the atrioventricular (AV) node cannot be used. We aimed at evaluating changes in AV nodal properties during administration of metoprolol from electrocardiogram data, and to support our findings with simulated data based on results from an electrophysiological study.</AbstractText>Sixty patients (age 71 ± 9 years, 42 men) with permanent AF were included in the RATe control in Atrial Fibrillation (RATAF) study. Two 15 min segments, during baseline and metoprolol administration, starting at 2 pm were analysed in this study. Atrial fibrillatory rate (AFR), heart rate (HR), and AV nodal parameters were assessed. The AV nodal parameters account for the probability of an impulse not taking the fast pathway, the absolute refractory periods of the slow and fast pathways (aRPs and aRPf), representing the functional refractory period, and their respective prolongation in refractory period. In addition, simulated RR series were generated that mimic metoprolol administration through prolonged AV conduction interval and AV node effective refractory period. During metoprolol administration, AFR and HR were significantly decreased and aRP was significantly prolonged in both pathways (aRPs: 337 ± 60 vs. 398 ± 79 ms, P < 0.01; aRPf: 430 ± 91 vs. 517 ± 100 ms, P < 0.01). Similar results were found for the simulated RR series, both aRPs and aRPf being prolonged with metoprolol (aRPs: 413 ± 33 vs. 437 ± 43 ms, P = 0.01; aRPf: 465 ± 40 vs. 502 ± 69 ms, P = 0.02).</AbstractText>The AV nodal parameters reflect expected changes after metoprolol administration, i.e. a prolongation in functional refractory period. The simulations confirmed that aRPs and aRPf may serve as an estimate of the functional refractory period.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,316 | The plasma B-type natriuretic peptide levels are low in males with stable ischemic heart disease (IHD) compared to those observed in patients with non-IHD: a retrospective study. | Although the plasma B-type natriuretic peptide (BNP) level is a marker of heart failure, it is unclear whether BNP per se plays a pivotal role for pathogenic mechanisms underlying the development of ischemic heart disease (IHD). In this study, we retrospectively examined the plasma BNP levels in stable patients with IHD and compared to stable patients with cardiovascular diseases other than IHD.</AbstractText>The study population was 2088 patients (1698 males and 390 females) who were admitted to our hospital due to IHD (n = 1,661) and non-IHD (n = 427) and underwent cardiac catheterization. Measurements of the hemodynamic parameters and blood sampling were performed.</AbstractText>The plasma BNP levels were significantly lower in the IHD group than in the non-IHD group (p<0.001). The multiple regression analysis examining the logBNP values showed that age, a male gender, low left ventricular ejection fraction, low body mass index, serum creatinine, atrial fibrillation and IHD per se were significant explanatory variables. When the total study population was divided according to gender, the plasma BNP levels were found to be significantly lower in the IHD group than in the non-IHD group among males (p<0.001), but not females (p = NS). Furthermore, a multiple logistic regression analysis of IHD showed the logBNP value to be a significant explanatory variable in males (regression coefficient: -0.669, p<0.001), but not females (p = NS).</AbstractText>The plasma BNP levels were relatively low in stable patients with IHD compared with those observed in stable patients with non-IHD; this tendency was evident in males. Perhaps, the low reactivity of BNP is causally associated with IHD in males. We hope that this study will serve as a test of future prospective studies.</AbstractText> |
11,317 | Combination of veno-arterial extracorporeal membrane oxygenation and hypothermia for out-of-hospital cardiac arrest due to Taxus intoxication. | A young woman presented with cardiac arrest following ingestion of yew tree leaves of the Taxus baccata species. The toxin in yew tree leaves has negative inotropic and dromotropic effects. The patient had a cardiac rhythm that alternated between pulseless electrical activity with a prolonged QRS interval and ventricular fibrillation. When standard resuscitation therapy including digoxin immune Fab was ineffective, a combination of extracorporeal membrane oxygenation (ECMO) and hypothermia was initiated. The total duration of low flow/no flow was 82 minutes prior to the initiation of ECMO. After 36 hours of ECMO (including 12 hours of electrical asystole), the patient's electrocardiogram had normalized and the left ventricular ejection fraction was 50%. At this time, dobutamine and the ECMO were stopped. The patient had a full neurologic recovery and was discharged from the intensive care unit after 5 days and from the hospital 1 week later. |
11,318 | Pathophysiology and Management of Arrhythmias Associated with Atrial Septal Defect and Patent Foramen Ovale. | Atrial septal defects (ASDs) are among the most common of congenital heart defects and are frequently associated with atrial arrhythmias. Atrial and ventricular geometrical remodelling secondary to the intracardiac shunt promotes evolution of the electrical substrate, predisposing the patient to atrial fibrillation and other arrhythmias. Closure of an ASD reduces the immediate and long-term prevalence of atrial arrhythmias, but the evidence suggests that patients remain at an increased long-term risk in comparison with the normal population. The closure technique itself and its timing impacts future arrhythmia risk profile while subsequent transseptal access following surgical or device closure is complicated. Newer techniques combined with increased experience will help to alleviate some of the difficulties associated with optimal management of arrhythmias in these patients. |
11,319 | The Use of Gene Therapy for Ablation of Atrial Fibrillation. | Atrial fibrillation is the most common clinically significant cardiac arrhythmia, increasing the risk of stroke, heart failure and morbidity and mortality. Current therapies, including rate control and rhythm control by antiarrhythmic drugs or ablation therapy, are moderately effective but far from optimal. Gene therapy has the potential to become an attractive alternative to currently available therapies for atrial fibrillation. Various gene transfer vectors have been developed for cardiovascular disease with viral vectors being most widely used due to their high efficiency. Several gene delivery methods have been employed on different therapeutic targets. With increasing understanding of arrhythmia mechanisms, novel therapeutic targets have been discovered. This review will evaluate state-of-art gene therapy strategies and approaches including sinus rhythm restoration and ventricular rate control that could eventually prevent or eliminate atrial fibrillation in patients. |
11,320 | Non Invasive ECG Mapping To Guide Catheter Ablation. | Since more than 100 years, 12-lead electrocardiography (ECG) is the standard-of-care tool, which involves measuring electrical potentials from limited sites on the body surface to diagnose cardiac disorder, its possible mechanism and the likely site of origin. Several decades of research has led to the development of a 252-lead-ECG and CT-scan based, three dimensional, electro-imaging modality to non-invasively map abnormal cardiac rhythms including fibrillation. These maps provide guidance towards ablative therapy and thereby help advance the management of complex heart rhythm disorders. Here, we describe the clinical experience obtained using non-invasive technique in mapping the electrical disorder and guide the catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats) and ventricular pre-excitation (Wolff-Parkinson-White syndrome). |
11,321 | How To Better Identify Patients That Do Not Benefit From Prophylactic ICD Therpy. | The implantable cardioverter defibrillator (ICD) has been demonstrated to improve survival by reducing sudden cardiac death (SCD) in patients with a low left ventricular ejection fraction (LVEF). Randomised trial data suggest that this mortality reduction is not constant among those implanted with a device, and has raised the significance of non-sudden cardiac death (non-SCD) as an important mode of death predicting limited benefit from ICD therapy. In this review article we explore the role of non-SCD and the risk prediction models that may aid identification of low LVEF patients unlikely to gain significant benefit from ICD therapy. |
11,322 | A Challenging Case Of Ventricular Arrhythmia In A Patient With Myocarditis: ICD Yes/No After Ablation. | In patients with myocarditis, early diagnosis and appropriate therapy are mandatory, as well as close clinical follow-up with particular regard to progression of disease and ventricular arrhythmia recurrences. The management of ventricular arrhythmias should follow current guidelines for ICD implantation, but new therapeutic options could be evaluated in these patients, such as combined epicardial/endocardial ablation and external wearable defibrillator. Particularly, depressed left ventricular ejection fraction (LVEF) represents the only risk marker for sudden cardiac death currently used in myocarditis, although the use of a single risk factor has limited utility. On this regard, combined analysis of myocardial tissue structure by cardiac magnetic resonance (CMR) and endomyocardial biopsy, in association with resting cardiac systolic function, could improve predictive accuracy for SCD in patients with myocarditis. |
11,323 | Left Atrial Diastolic Dysfunction And Pulmonary Venous Hypertension In Atrial Fibrillation: Clinical, Hemodynamic And Echocardiographic Characteristics. | Left ventricular diastolic dysfunction has been well described; diastolic abnormalities of the LA are less frequently recognized and poorly understood.</AbstractText>The purpose of this study was to investigate the clinical, hemodynamic and echocardiographic features of left atrial (LA) diastolic dysfunction.</AbstractText>Patients with atrial fibrillation (AF), severe LA enlargement, and pulmonary venous hypertension (PVH, Group 1) were compared to patients with pulmonary arterial hypertension (PAH), normal LA size and sinus rhythm (Group 2). All underwent right heart catheterization and transthoracic echo to evaluate hemodynamics and LA function. Mitral regurgitation was evaluated by transesophageal echocardiography. LA diastolic function was measured by comparing filling fraction, pulmonary venous flow and compliance.</AbstractText>Right atrial, pulmonary artery systolic and mean pressures were similar. Mean wedge pressure were increased in Group 1, 20.8±2.6 versus 9.7±2.8 mm of Hg (p<0.0001). The most striking hemodynamic difference was large V wave in Group 1 without significant mitral regurgitation. LA filling fraction was abnormal in Group 1, 11.4%±8.5 compared to Group 2, 111.5%±44 (p<0.0001). LA compliance was 0.39±0.27 ml/m2/mmHg in Group 1 versus 6.8±4.54 ml/m2/mmHg in Group 2 (p=0.001). There was a strong negative correlation between the V wave and LA filling fraction (r= 0.756, p<0.001). The ratio of the height of the transmitral E wave divided by the S/D ratio (the LA diastolic dysfunction index) correlated very strongly with the V wave (r=0.907, p<0.001).</AbstractText>LA diastolic dysfunction is present in some patients with long standing AF and PVH. LA diastolic dysfunction, in addition to left ventricular diastolic dysfunction, may contribute to the syndrome of heart failure with preserved left ventricular systolic function.</AbstractText> |
11,324 | Evaluation Of Patients With Early Repolarization Syndrome. | In recent years, the early repolarization pattern has emerged as a risk factor for malignant ventricular arrhythmias and sudden cardiac death. The identification of the subset of patients who are at high risk of sudden death represents a significant challenge to the clinician. Multiple clinical and ECG features have been associated with an increased risk of sudden deathin however the majority of risk factors confer a small increase in absolute risk. The present article reviews current evidence and potential management strategies in patients with early repolarization. |
11,325 | Evaluation of Tp-Te interval and Tp-Te/QTc ratio in patients with coronary artery ectasia. | Coronary artery ectasia (CAE) is commonly defined as local or generalized dilatation of a coronary vessel up to 1.5 times the diameter of an adjacent vessel. Tp-Te interval and Tp-Te/QT ratio have emerged as novel electrocardiographic markers of increased dispersion of ventricular repolarization. The aim of this study was to evaluate ventricular repolarization by using Tp-Te interval and Tp-Te/QT ratio in patients with CAE.</AbstractText>Patients' records were retrospectively analyzed. Electrocardiogram of 28 patients, who were diagnosed as CAE were obtained and scanned. T wave peak to end interval, QT and corrected QT intervals and some other ECG intervals were measured. Electrocardiograms of age and sex matched 22 control individuals were also analyzed for comparison. Patients with critical coronary stenosis, moderate or severe valve disease, left and/or right heart failure, left and/or right ventricle hypertrophy, atrial fibrillation, moderate or severely abnormal electrolytes, right or left bundle block or patients who got pacemaker or ICD implanted and who undergo hemodialyses were excluded.</AbstractText>Baseline characteristics and QT, QTc intervals were similar in both groups. Tp-Te (97.71 ± 8.7 vs 85.23 ± 7.1; p < 0.001) and Tp-Te/QT (0.22 ± 0.0 vs 0.20 ± 0.0; p < 0.001) were significantly worse in CAE group.</AbstractText>T wave peak to end interval is a measure of transmural dispersion of repolarization in the left ventricle and accepted as a surrogate for increased ventricular arrhythmogenesis risk. Tp-Te and Tp-Te/QT are relatively new markers which also indicate repolarization defects. Our results show that CAE patients significantly higher values of Tp-Te and Tp-Te/QT than controls. These measurements may indicate increased arrhythmogenesis risk for individuals with CAE.</AbstractText> |
11,326 | Quality of life and functional outcomes 12 months after out-of-hospital cardiac arrest. | Out-of-hospital cardiac arrest (OHCA) is a significant global health problem. There has been considerable investment in improving the emergency medical response to OHCA, with associated improvements in survival. However, concern remains that survivors have a poor quality of life. This study describes the quality of life of OHCA survivors at 1-year postarrest in Victoria, Australia.</AbstractText>Adult OHCA patients who arrested between 2010 and 2012 were identified from the Victorian Ambulance Cardiac Arrest Registry. Paramedics attended 15 113 OHCA patients of which 46.3% received an attempted resuscitation. Nine hundred and twenty-seven (13.2%) survived to hospital discharge of which 76 (8.2%) died within 12 months. Interviews were conducted with 697 (80.7%) patients or proxies, who were followed-up via telephone interview, including the Glasgow Outcome Scale-Extended, the 12-item short form health survey, and the EuroQol. The majority (55.6%) of respondents had a good recovery via the Glasgow Outcome Scale-Extended≥7 (41.1% if patients who died postdischarge were included and nonrespondents were assumed to have poor recovery). The mean EuroQol index score for respondents was 0.82 (standard deviation, 0.19), which compared favorably with an adjusted population norm of 0.81 (standard deviation, 0.34). The mean 12-item short form Mental Component Summary score for patients was 53.0 (standard deviation, 10.2), whereas the mean Physical Component Summary score was 46.1 (standard deviation, 11.2).</AbstractText>This is the largest published study assessing the quality of life of OHCA survivors. It provides good evidence that many survivors have an acceptable quality of life 12 months postarrest, particularly in comparison with population norms.</AbstractText>© 2014 American Heart Association, Inc.</CopyrightInformation> |
11,327 | Tako-tsubo cardiomyopathy following catheter ablation of atrial fibrillation. | Tako-tsubo cardiomyopathy is characterized by reversible left ventricular dysfunction following emotional or surgical stress. Unlike the well-known complications of catheter ablation (CA) of atrial fibrillation (AF), Tako-tsubo cardiomyopathy has been rarely reported so far. We report a case of acute reversible left heart failure following successful CA of paroxysmal AF in a patient with a history of panic disorder. |
11,328 | The Janus face of adenosine: antiarrhythmic and proarrhythmic actions. | Adenosine is a ubiquitous, endogenous purine involved in a variety of physiological and pathophysiological regulatory mechanisms. Adenosine has been proposed as an endogenous antiarrhythmic substance to prevent hypoxia/ischemia-induced arrhythmias. Adenosine (and its precursor, ATP) has been used in the therapy of various cardiac arrhythmias over the past six decades. Its primary indication is treatment of paroxysmal supraventricular tachycardia, but it can be effective in other forms of supraventricular and ventricular arrhythmias, like sinus node reentry based tachycardia, triggered atrial tachycardia, atrioventricular nodal reentry tachycardia, or ventricular tachycardia based on a cAMP-mediated triggered activity. The main advantage is the rapid onset and the short half life (1- 10 sec). Adenosine exerts its antiarrhythmic actions by activation of A1 adenosine receptors located in the sinoatrial and atrioventricular nodes, as well as in activated ventricular myocardium. However, adenosine can also elicit A2A, A2B and A3 adenosine receptor-mediated global side reactions (flushing, dyspnea, chest discomfort), but it may display also proarrhythmic actions mediated by primarily A1 adenosine receptors (e.g. bradyarrhythmia or atrial fibrillation). To avoid the non-specific global adverse reactions, A1 adenosine receptor- selective full agonists (tecadenoson, selodenoson, trabodenoson) have been developed, which agents are currently under clinical trial. During long-term administration with orthosteric agonists, adenosine receptors can be internalized and desensitized. To avoid desensitization, proarrhythmic actions, or global adverse reactions, partial A1 adenosine receptor agonists, like CVT-2759, were developed. In addition, the pharmacologically "silent" site- and event specific adenosinergic drugs, such as adenosine regulating agents and allosteric modulators, might provide attractive opportunity to increase the effectiveness of beneficial actions of adenosine and avoid the adverse reactions. |
11,329 | Future perspectives in the pharmacological treatment of atrial fibrillation and ventricular arrhythmias in heart failure. | Heart failure (HF) is a clinical syndrome characterized by significant impairment of cardiac ventricular function. Atrial fibrillation (AF) is the most commonly observed sustained arrhythmia in clinical practice. Both HF and AF are associated with increased morbidity and mortality and their prevalence increases with age. Approximately 50% of patients with moderate HF die due to ventricular fibrillation that leads to sudden cardiac death. Patients with AF exhibit increased mortality due to HF and stroke. HF and AF often co-exist, and the development of the other condition further deteriorates prognosis. Both chronic HF and AF lead to structural and electrophysiological changes in the heart called remodeling, modifying therapeutic targets including those for antiarrhythmic intervention. Current pharmacological treatment of arrhythmias has major limitations due to low efficacy and serious adverse effects. In this review, the main aspects of electrical remodeling in HF and AF are discussed along with possible novel targets identified for future pharmacological antiarrhythmic therapy. |
11,330 | Role of gap junction channel in the development of beat-to-beat action potential repolarization variability and arrhythmias. | The short-term beat-to-beat variability of cardiac action potential duration (SBVR) occurs as a random alteration of the ventricular repolarization duration. SBVR has been suggested to be more predictive of the development of lethal arrhythmias than the action potential prolongation or QT prolongation of ECG alone. The mechanism underlying SBVR is not completely understood but it is known that SBVR depends on stochastic ion channel gating, intracellular calcium handling and intercellular coupling. Coupling of single cardiomyocytes significantly decreases the beat-to-beat changes in action potential duration (APD) due to the electrotonic current flow between neighboring cells. The magnitude of this electrotonic current depends on the intercellular gap junction resistance. Reduced gap junction resistance causes greater electrotonic current flow between cells, and reduces SBVR. Myocardial ischaemia (MI) is known to affect gap junction channel protein expression and function. MI increases gap junction resistance that leads to slow conduction, APD and refractory period dispersion, and an increase in SBVR. Ultimately, development of reentry arrhythmias and fibrillation are associated post-MI. Antiarrhythmic drugs have proarrhythmic side effects requiring alternative approaches. A novel idea is to target gap junction channels. Specifically, the use of gap junction channel enhancers and inhibitors may help to reveal the precise role of gap junctions in the development of arrhythmias. Since cell-to-cell coupling is represented in SBVR, this parameter can be used to monitor the degree of coupling of myocardium. |
11,331 | ATP-sensitive potassium channel modulators and cardiac arrhythmias: an update. | Ischemia and heart failure-related cardiac arrhythmias, both atrial (e.g., atrial fibrillation) and ventricular (e.g., malignant tachyarrhythmias) represent a leading cause of morbidity and mortality worldwide. Despite the progress made in the last decade in understanding their pathophysiological mechanisms there is still an unmet need for safer and more efficacious pharmacological treatment, especially when considering the drawbacks and complications of implantable devices. Cardiac ATP-sensitive potassium channels located in the sarcolemmal membrane (sarcKATP) and the inner mitochondrial membrane (mitoKATP) have emerged as crucial controllers of several key cellular functions. In the past three decades a tremendous amount of research led to their structural and functional characterization unveiling both a protective role in cardiac adaptive responses to metabolic stress and a seemingly paradoxical role in promoting as well as protecting against atrial and ventricular arrhythmias. On the other hand, several KATP inhibitors have emerged as potential ischemia selective antiarrhythmic drugs. In this respect, cardioselective, chamber specific and combined sarcKATP and mitoKATP modulators currently represent a promising field for drug development. |
11,332 | Atrial fibrillation in decompensated heart failure: associated factors and in-hospital outcome. | Studies on atrial fibrillation (AF) in decompensated heart failure (DHF) are scarce in Brazil.</AbstractText>To determine AF prevalence, its types and associated factors in patients hospitalized due to DHF; to assess their thromboembolic risk profile and anticoagulation rate; and to assess the impact of AF on in-hospital mortality and hospital length of stay.</AbstractText>Retrospective, observational, cross-sectional study of incident cases including 659 consecutive hospitalizations due to DHF, from 01/01/2006 to 12/31/2011. The thromboembolic risk was assessed by using CHADSVASc score. On univariate analysis, the chi-square, Student t and Mann Whitney tests were used. On multivariate analysis, logistic regression was used.</AbstractText>The prevalence of AF was 40%, and the permanent type predominated (73.5%). On multivariate model, AF associated with advanced age (p < 0.0001), non-ischemic etiology (p = 0.02), right ventricular dysfunction (p = 0.03), lower systolic blood pressure (SBP) (p = 0.02), higher ejection fraction (EF) (p < 0.0001) and enlarged left atrium (LA) (p < 0.0001). The median CHADSVASc score was 4, and 90% of the cases had it ≥ 2. The anticoagulation rate was 52.8% on admission and 66.8% on discharge, being lower for higher scores. The group with AF had higher in-hospital mortality (11.0% versus 8.1%, p = 0.21) and longer hospital length of stay (20.5 ± 16 versus 16.3 ± 12, p = 0.001).</AbstractText>Atrial fibrillation is frequent in DHF, the most prevalent type being permanent AF. Atrial fibrillation is associated with more advanced age, non-ischemic etiology, right ventricular dysfunction, lower SBP, higher EF and enlarged LA. Despite the high thromboembolic risk profile, anticoagulation is underutilized. The presence of AF is associated with longer hospital length of stay and high mortality.</AbstractText> |
11,333 | Electrical storm in systemic sclerosis: Inside the electroanatomic substrate. | We report the case of a 63-year-old woman affected by a severe form of systemic scleroderma with pulmonary involvement (interstitial fibrosis diagnosed by biopsy and moderate pulmonary hypertension) and cardiac involvement (paroxysmal atrial fibrillation, right atrial flutter treated by catheter ablation, ventricular tachyarrhythmias, previous dual chamber implantable cardioverter defibrillator implant). Because of recurrent electrical storms refractory to iv antiarrhythmic drugs the patient was referred to our institution to undergo catheter ablation. During electrophysiological procedure a 3D shell of cardiac anatomy was created with intracardiac echocardiography pointing out a significant right ventricular dilatation with a complex aneurysmal lesion characterized by thin walls and irregular multiple trabeculae. A substrate-guided strategy of catheter ablation was accomplished leading to a complete electrical isolation of the aneurism and to the abolishment of all abnormal electrical activities. The use of advanced strategies of imaging together with electroanatomical mapping added important information to the complex arrhythmogenic substrate and improved efficacy and safety. |
11,334 | Amiodarone-related thyroid dysfunction. | Nowadays, amiodarone is the most commonly used antidysrhythmic drug in clinical practice. It is highly effective in the management of recurrent ventricular dysrhythmias, paroxysmal supraventricular dysrhythmias, including atrial fibrillation and flutter, and in the maintenance of sinus rhythm after electrical cardioversion of atrial fibrillation. Moreover, it has the added benefit of being well tolerated in patients with both normal and impaired left ventricular systolic function. Despite amiodarone's potent antidysrhythmic actions, its use is hampered by numerous adverse effects on various organs, including the thyroid. Adverse effects are becoming more prevalent given the increasing incidence of dysrhythmias and wider amiodarone use. Thus, physicians and patients should both be aware of the potential thyroid-specific sequelae. However, amiodarone is likely to remain a significant problem for endocrinologists as concerns exist over the use of the new alternative antiarrhythmic agent, dronedarone, especially in patients with heart failure and left ventricular dysfunction because of the risk of hepatic injury and increased mortality. The final diagnostic and therapeutic approaches must be discussed among the patient, the general practitioner, the cardiologist, and the endocrinologist. |
11,335 | Effects of levosimendan in patients with left ventricular hypertrophy undergoing aortic valve replacement. | Left ventricular hypertrophy is associated with adverse outcomes, including death, during cardiac surgery. This may be facilitated by an increased oxygen demand and diastolic dysfunction. Levosimendan augments haemodynamics without further oxygen consumption and improves echocardiographic indices of diastolic dysfunction. This study aimed to describe the haemodynamic effects of short-term pre- and intra-operative levosimendan infusion including advanced echocardiographic measures of diastolic and systolic heart function.</AbstractText>The study was randomised, double-blinded and placebo-controlled performed at a single-centre university hospital. Patients with left ventricular hypertrophy and ejection fraction > 45% scheduled for single procedure aortic valve replacement were included and randomised to infusion of either levosimendan 0.1 μg/kg/min or placebo from 4 h before anaesthesia to the end of surgery. Outcome measures were echocardiographic indices of left ventricular diastolic function: E/e' (primary endpoint), e', e'/a' and indices of systolic function: longitudinal strain, ejection fraction and s'. Patients were followed until 6 months after surgery. In addition, invasive haemodynamic measures were obtained perioperatively.</AbstractText>The trial was prematurely terminated due to an overall high incidence of post-operative atrial fibrillation (15/20, P = 0.002) after inclusion of 20 patients. The relative decrease in perioperative cardiac index was lower (P = 0.016) in the levosimendan group. There was no difference in E/e', and similar results were found for all measures of systolic function.</AbstractText>Short-term levosimendan caused a transient relative increase in cardiac index, but no effect was seen on the first post-operative day and up to 6 months post-operatively with indices of systolic and diastolic heart function.</AbstractText>© 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.</CopyrightInformation> |
11,336 | Incidence and timing of serious arrhythmias after early revascularization in non ST-elevation myocardial infarction. | In contrast to ST-elevation myocardial infarction (STEMI), in non-STEMI (NSTEMI) patients the need for continuous rhythm monitoring in a coronary care unit, respective incidence and timing of serious arrhythmias are poorly defined.</AbstractText>We used a derivation-validation design and data from two independent prospective cohorts of consecutive haemodynamically stable NSTEMI patients to evaluate the incidence and timing of serious arrhythmias after successful early percutaneous revascularization. Serious arrhythmia was prospectively defined as any arrhythmia that requires immediate medical attention including persistent ventricular tachycardia (>30 s), ventricular fibrillation, asystole, and high degree atrioventricular (AV)-block requiring pacemaker insertion during hospitalization.</AbstractText>In the derivation cohort, among 228 NSTEMI patients who underwent successful early percutaneous revascularization, one patient (0.4%, 95% confidence interval 0.02-2.8%) had a serious arrhythmia which occurred 21 h after revascularization. In the validation cohort, among 293 NSTEMI patients who underwent successful early percutaneous revascularization, no patient (0%, 95% confidence interval 0-1.6%) had a serious arrhythmia after revascularization.</AbstractText>The incidence of serious arrhythmias in NSTEMI patients after successful early revascularization seems to be very low.</AbstractText>© The European Society of Cardiology 2014.</CopyrightInformation> |
11,337 | Evaluation rhythm problems in unexplained syncope etiology with implantable loop recorder. | Syncope is a frequent complaint in children and adolescents and may be a significant sign of serious pathology. Although patient history, family history, and physical examination are sufficient to reach a diagnosis in most cases of syncope, the cause of syncope still cannot be determined after initial investigation in one-third to half of all patients. The aim of this study was to evaluate the diagnostic yield of implantable loop recorder (ILR) in children with unexplained syncope.</AbstractText>A retrospective review was carried out of clinical data, indications, findings, and a final management strategy in patients who underwent ILR implantation.</AbstractText>A total of 12 patients with a mean age of 9.4 ± 4.5 years underwent ILR (Reveal Plus; Medtronic) implantation. ILR implantation indication was syncope in all of the patients. Family history, routine cardiac assessment, including resting 12-lead electrocardiogram, transthoracic echocardiography, 24 h Holter recording, and event recorder findings, were normal with the exception of one patient with (previously corrected) tetralogy of Fallot. After an average of 20 months (range, 1-36 months), six patients developed symptoms. ILR memory showed torsades de pointes-ventricular fibrillation (n = 3), catecholaminergic polymorphic ventricular tachycardia (n = 1), asystole and ventricular tachycardia (n = 1), and normal sinus rhythm (n = 1). At the time of writing six patients were still in follow up with no symptoms after an average of 25.2 months.</AbstractText>Implantable loop recorder plays an important role in the diagnosis of life-threatening arrhythmias in which syncope is otherwise unexplained. ILR implantation should be remembered in children whose symptoms are strongly correlated with rhythm disturbances.</AbstractText>© 2014 Japan Pediatric Society.</CopyrightInformation> |
11,338 | [Ten years of early defibrillation: "Bochum against sudden cardiac death". Acceptance and critical analysis of using automated external defibrillators]. | There is a comprehensive early defibrillation program in Bochum (Germany); since 2003 a total of 175 automated external defibrillators (AEDs) have been installed in urban areas by the city of Bochum and private companies. These were preferably installed in places with high foot traffic, e.g., public buildings, companies, and event/shopping centers. Approximately 15,000 laypeople who work in the vicinity of the AED locations were trained in the use of defibrillators and in basic resuscitation. In addition, rescue workers on fire trucks and medically trained personnel in physicians' medical practices were equipped as "first responders" with AEDs.</AbstractText>After an initiation phase, all available information after each AED use since August 2004 has been collected by the project coordinator. During the period of data collection (August 2004 to August 2013), an AED was used in a total of 17 patients who had suffered sudden cardiac death (SCD) under the project in Bochum. Eleven patients had primary ventricular fibrillation (VF). Six of these survived without neurological deficit. In another 6 patients, a nondefibrillatable rhythm disorder was diagnosed. The AEDs are reliable and showed impeccable rhythm analysis before the instructions to provide any necessary shock.</AbstractText>Compared to the number of existing units and an estimated number of 37-100 SCD/100,000, the use of the AEDs only 17 times appears relatively small. To improve the effectiveness of the AED program in Bochum, an analysis of the emergency service responses, which were necessary because of sudden circulatory collapse, is currently being performed. This will allow areas with an increased incidence of SCD to be identified and a plan for the strategic placement of AED and emergency services can be made.</AbstractText> |
11,339 | Combined actions of ivabradine and ranolazine reduce ventricular rate during atrial fibrillation. | Ventricular rate during atrial fibrillation (AF) can be reduced by slowing atrioventricular (AV) node conduction and/or by decreasing dominant frequency of AF. We investigated whether combined administration of ivabradine and ranolazine reduces ventricular rate during AF.</AbstractText>Ivabradine (maximum clinical dose, 0.25 mg/kg, and 0.10 mg/kg, i.v.) and ranolazine (2.4 mg/kg, i.v., bolus followed by 0.135 mg/kg/min) were studied in an anesthetized pig (N = 16) model of AF. Combined administration of 0.25 mg/kg ivabradine with ranolazine reduced ventricular rate during AF by 51.9 ± 9.7 beats/min (23%, P = 0.017) and dominant frequency of AF by 2.8 ± 0.5 Hz (32%, P = 0.005). It increased PR (P = 0.0002, P = 0.0007) and A-H intervals (P = 0.047, P = 0.002) during pacing at 130 and 180 beats/min, respectively, to a greater degree than additive effects of single agents. Combined administration of 0.1 mg/kg ivabradine with ranolazine exceeded additive effects of single agents on A-H intervals and dominant frequency of AF. Moreover, ranolazine potentiated low-dose ivabradine's reduction in ventricular rate, as combined administration more than doubled effects of the higher ivabradine dose alone and was similar to the combination with the higher dose. Neither drug nor their combination affected contractility (left ventricular [LV] dP/dt), QT or His-ventricular (H-V) intervals, or mean arterial pressure during sinus rhythm or AF.</AbstractText>Combined administration of ivabradine and ranolazine at clinically safe levels decreases ventricular rate during AF by reducing AV node conduction and AF dominant frequency without QT prolongation or depression in contractility. Targeting these actions offers intrinsic advantages over conventional nodal agents, which can reduce contractility.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,340 | Electrical storm and heart failure worsening in implantable cardiac defibrillator patients. | In patients with an implantable cardiac defibrillator (ICD), electrical storm (ES) is associated with increased sudden and non-sudden cardiac mortality, the latter largely due to worsening heart failure (HF). Aim of this study is to test the association between ES and impending pump failure in patients with known chronic HF and ICD.</AbstractText>Inclusion criteria were a previous history of chronic HF, former ICD implant, and hospital admission for HF worsening, or ES, or unclustered ventricular tachyarrhythmias (VTs/VFs). Patients with concomitant stable HF or HF worsening due to another specific cause were excluded. Primary endpoint was all cause mortality. Main secondary endpoint was time to first rehospitalization. Prospective, observational study on 146 patients: 34 with ES, 30 with unclustered VTs/VFs, and 82 with HF worsening. During the 5 years of follow-up, there was no significant difference between survival estimates between ES and HF worsening (P = 0.7), while both were significantly lower than survival of unclustered VT/VF patients (all log rank P < 0.05). Hospitalization-free time was significantly lower in both the ES group and in the HF worsening group when compared with unclustered VT/VF patients (all log rank P < 0.05). There was no significant difference between hospitalization estimates between ES and HF worsening.</AbstractText>Heart failure patients admitted for ES have major similarities with patients admitted for HF clinical decompensation such as similar survival, cause of death and time to first rehospitalization. There is evidence suggesting that, in this population, ES could be considered as a clinical manifestation of HF worsening.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,341 | [Electrocardiologic opportunities for the treatment of recurrent ventricular tachycardia on the example of a patient with arrhythmogenic right ventricular dysplasia]. | Arrhythmogenic right ventricular dysplasia is a genetic disease, in which pathologic fibrofatty tissue occurs mainly in the right ventricle of the heart. Changes in heart muscle predispose to arrhythmias such as ventricular tachycardia or ventricular fibrillation, so these patients are candidates for implantation of implantable cardioverter-defibrillator. Furthermore, depending on the indication, RF-ablation is performed, which, due to changes in morphology of the heart muscle, are often difficult and of uncertain efficacy. In this paper we present a case of a patient with implanted cardioverter-defibrillator for primary prevention of sudden cardiac death. Initially, the patient experienced only complications related to the possession of the device, but due to the significant progression of the disease and symptoms, the device turned out to be necessary. In addition, the patient underwent complex electrophysiology procedures to control recurrent episodes of ventricular tachycardia. Treatment of cardiac arrhythmias in arrhythmogenic right ventricular dysplasia is problematic both because of the inability to predict the course of disease in asymptomatic patients, as well as due to the difficulty of carrying out effective ablation of arrhythmia foci in morphologically altered myocardium. |
11,342 | Atrial fibrillation in Indigenous and non-Indigenous Australians: a cross-sectional study. | To examine the prevalence of atrial fibrillation (AF) and cardiac structural characteristics in Indigenous and non-Indigenous Australians.</AbstractText>Retrospective cross-sectional study linking clinical, echocardiography and administrative databases over a 10-year period.</AbstractText>A tertiary, university teaching hospital in Adelaide, Australia.</AbstractText>Indigenous and non-Indigenous Australians.</AbstractText>AF prevalence and echocardiographic characteristics.</AbstractText>Indigenous Australians with AF were significantly younger compared to non-Indigenous Australians (55±13 vs 75±13 years, p<0.001). As a result, racial differences in AF prevalence and left atrial diameter varied according to age. In those under 60 years of age, Indigenous Australians had a significantly greater AF prevalence (2.57 vs1.73%, p<0.001) and left atrial diameters (39±7 vs 37±7 mm, p<0.001) compared to non-Indigenous Australians. In those aged 60 years and above, however, non-Indigenous Australians had significantly greater AF prevalence (9.26 vs 4.61%, p<0.001) and left atrial diameters (39±7 vs 37±7 mm, p<0.001). Left ventricular ejection fractions were less in Indigenous Australians under 60 years of age (49±14 vs 55±11%, p<0.001) and not statistically different in those aged 60 years and above (47±11 vs 52±13, p=0.074) compared to non-Indigenous Australians. Despite their younger age, Indigenous Australians with AF had similar or greater rates of cardiovascular comorbidities than non-Indigenous Australians with AF.</AbstractText>Young Indigenous Australians have a significantly greater prevalence of AF than their non-Indigenous counterparts. In contrast, older non-Indigenous Australians have a greater prevalence of AF compared to their Indigenous counterparts. These observations may be mediated by age-based differences in comorbid cardiovascular conditions, left atrial diameter and left ventricular ejection fraction. Our findings suggest that AF is likely to be contributing to the greater burden of morbidity and mortality experienced by young Indigenous Australians. Further study is required to elucidate whether strategies to prevent and better manage AF in Indigenous Australians may reduce this burden.</AbstractText>Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.</CopyrightInformation> |
11,343 | An ECG changed the life of a young boy: a case of arrhythmogenic right ventricular dysplasia. | Arrhythmogenic right ventricular dysplasia (ARVD) is a progressive condition with the right ventricular myocardium being replaced by fibrofatty tissue. It is a hereditary disorder mostly caused by desmosome gene mutations. The prevalence of arrhythmogenic right ventricular cardiomyopathy is about 1/1000-5000. Clinical presentation is usually related to ventricular tachycardias, syncope, presyncope or ventricular fibrillation leading to cardiac arrest, mostly in young people and athletes. We report a case of a 17-year-old boy from Turkey, who was referred to our cardiology department for an ECG, required of him prior to joining a football team. |
11,344 | Prophylactic treatment with coenzyme Q10 in patients undergoing cardiac surgery: could an antioxidant reduce complications? A systematic review and meta-analysis. | Coenzyme Q10 (CoQ10) is a lipid-soluble antioxidant that could have beneficial effects in patients undergoing cardiac surgery with cardiopulmonary bypass. There is no clear evidence about its clinical effects or a systematic review published yet. We aimed to conduct a systematic review and meta-analysis of the literature to elucidate the role of coenzyme Q10 in preventing complications in patients undergoing cardiac surgery with cardiopulmonary bypass. We searched the PubMed Database using the following keywords: Coenzyme Q10, ubiquinone, ubiquinol, CoQ10, Heart Surgery, Cardiac surgery. Articles were systematically retrieved, selected, assessed and summarized for this review. We performed separate meta-analyses for different outcomes (inotropic drug requirements after surgery, incidence of ventricular arrhythmias and atrial fibrillation, cardiac index 24 h after surgery and hospital stay), estimating pooled odds ratios (ORs) or mean differences of the association of CoQ10 administration with the risk of these outcomes. Eight clinical trials met our inclusion criteria. Patients with CoQ10 treatment were significantly less likely to require inotropic drugs after surgery {OR [95% confidence interval (CI) 0.47 (0.27-0.81)]}, and to develop ventricular arrhythmias after surgery [OR (95% CI) 0.05 (0.01-0.31)]. However, CoQ10 treatment was not associated with Cardiac index 24 h after surgery [mean difference (95% CI) 0.06 (-0.30 to 0.43)], hospital stay (days) [mean difference (95% CI) -0.61 (-4.61 to 3.39)] and incidence of atrial fibrillation [OR (95% CI) 1.06 (0.19-6.04)]. Since none of the clinical trials included in this review report any adverse effects associated to CoQ10 administration, and coenzyme Q10 has been demonstrated to be safe even at much higher doses in other studies, we conclude that CoQ10 should be considered as a prophylactic treatment for preventing complications in patients undergoing cardiac surgery with cardiopulmonary bypass. However, better quality randomized, controlled trials are needed to clarify the role of CoQ10 in patients undergoing cardiac surgery with cardiopulmonary bypass. |
11,345 | Cardiac and renal fibrosis in chronic cardiorenal syndromes. | In recent years, there has been considerable interest in cellular and tissue responses to injury that result in the deposition of extracellular matrix, collagen, elastic fibers, and the histopathological development of fibrosis. In the myocardium, fibrosis results in many recognizable clinical features, including PR interval prolongation, heart block, bundle branch block, left ventricular dyssynergy, anisotropy, atrial fibrillation, ventricular arrhythmias, systolic and diastolic dysfunction, heart failure, and cardiac death. In the kidneys, fibrosis in the glomerulus leads to glomerular sclerosis, and in the inner cortex and medulla, tubulointerstitial fibrosis leads to a reduction in renal filtration function and rapidly progressive chronic kidney disease. There are a great number of potential early mediators of cellular damage in response to events such as ischemia, neurohormonal activation, biomechanical stretch, and abnormal cell signaling. However, many studies suggest that interstitial cells in both organs, including macrophages, T lymphocytes, fibroblasts, and myofibroblasts, have common communication systems that utilize galectin-3 and transforming growth factor-β that result in the upregulation and proliferation of fibroblasts and myofibroblasts, which produce and secrete procollagen I. Procollagen I cross-links in the extracellular space to form mature collagen, which is a fundamental unit of organ fibrosis. Future research will be concentrating on the pathogenic mechanisms that turn on fibrosis and on therapeutic targets that can either prevent the activation of fibroblasts or limit their repair response to injury. |
11,346 | Cardioverter-defibrillator implantation and generator replacement in the octogenarian. | Increase in life expectancy has led to increased rate of implantable cardioverter-defibrillator (ICD) implantation in patients in their 80s, but there are no current formal recommendations to guide physicians when elderly patients with ICDs require elective unit replacement (EUR). This study aims at assessing survival and rates of ICD therapies in patients who have had ICD implantation or EUR above the age of 80, focusing on the latter.</AbstractText>Retrospective analysis of a prospectively kept database of all ICD-related procedures carried out in a single tertiary centre. Patients 80 years of age or older submitted to ICD implantation (n = 42) or EUR (n = 34) between November 1991 and May 2012 were included. Using collected baseline and outcome data from this cohort, we assessed survival of these patients and the rates of ICD therapies. Median additional years of life after ICD implantation and ICD EUR in patients who died before data retrieval was 2.5 and 1.2, respectively, and while 65% of deceased patients after ICD implantation died in the first 3 years after the procedure, 50% of deceased post-ICD EUR patients died within the first year. Mortality rates at 1 and 2 years post-EUR were 23.1 and 38.1%, respectively. Furthermore, ventricular tachycardia occurred in a small minority of patients after EUR (16.7%) and no ventricular fibrillation-triggered ICD therapies were reported in both groups.</AbstractText>In octogenarians who are due for an ICD EUR, careful thought should be given to the current clinical status, comorbidities, and general frailty prior to considering them for the procedure. A survival benefit from ICD EUR in this age stratum is not likely.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,347 | Unnatural history of tetralogy of Fallot: prospective follow-up of 40 years after surgical correction. | Prospective data on long-term survival and clinical outcome beyond 30 years after surgical correction of tetralogy of Fallot are nonexistent.</AbstractText>This longitudinal cohort study consists of the 144 patients with tetralogy of Fallot who underwent surgical repair at <15 years of age between 1968 and 1980 in our center. They are investigated every 10 years. Cumulative survival (data available for 136 patients) was 72% after 40 years. Late mortality was due to heart failure and ventricular fibrillation. Seventy-two of 80 eligible survivors (90%) participated in the third in-hospital investigation, consisting of ECG, Holter, echocardiography, cardiopulmonary exercise testing, N-terminal pro-brain natriuretic peptide measurement, cardiac magnetic resonance (including dobutamine stress testing), and the Short Form-36 questionnaire. Median follow-up was 36 years (range, 31-43 years). Cumulative event-free survival was 25% after 40 years. Subjective health status was comparable to that in the normal Dutch population. Although systolic right and left ventricular function declined, peak exercise capacity remained stable. There was no progression of aortic root dilation. A previous shunt operation, low temperature during surgery, and early postoperative arrhythmias were found to predict late mortality (hazard ratio, 2.9, 1.1, and 2.5, respectively). An increase in QRS duration and a deterioration of exercise tolerance and ventricular dysfunction did not predict mortality. Insertion of a transannular patch was a predictor for late arrhythmias (hazard ratio, 4.0; 95% confidence interval, 1.2-13.4).</AbstractText>Although many patients needed a reoperation or developed arrhythmias, late mortality was low, and the clinical condition and subjective health status of most patients remained good. Previous shunt, low temperature during surgery, and early postoperative arrhythmias were found to predict late mortality.</AbstractText>© 2014 American Heart Association, Inc.</CopyrightInformation> |
11,348 | Antiarrhythmic effect of uridine and uridine-5'-monophosphate in acute myocardial ischemia. | Experiments on rats with acute myocardial ischemia accompanied by early postocclusive arrhythmias have shown normalizing, energy-stabilizing, and antiarrhythmic effects of uridine and uridine-5'-monophosphate. The drugs decreased lactate and restored reserves of glycogen and creatine phosphate depleted by ischemia. Uridine and uridine-5'-monophosphate significantly decreased the severity of ventricular arrhythmias. Both drugs reduced the incidence and duration of fibrillation. Uridine -5'-monophosphate demonstrated most pronounced antifibrillatory effectiveness. We hypothesize that the antiarrhythmic effect of the drugs is determined by their capacity to activate energy metabolism. |
11,349 | Resistant hypertension: risk factors, subclinical atherosclerosis, and comorbidities among adults-the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). | The frequency of resistant hypertension-defined as blood pressure (BP) ≥140/90 mm Hg with proven use of three antihypertensive medications, or as the use of four antihypertensive drug classes regardless of BP-is unknown in low-middle-income countries. Using data from the Brazilian Longitudinal Study of Adult Health, a cohort of 15,105 civil servants aged 35 to 74 years, the authors identified 4116 patients taking treatment for hypertension, 11% of who had resistant hypertension. These participants were more likely to be older, black, less educated, poorer, and obese. The adjusted prevalence ratios (95% confidence intervals) were diabetes, 1.44 (1.20-1.72); glomerular filtration rate (<60 mL/min/1.72 m(2) ), 1.95 (1.60-2.38); albumin-to-creatinine ratio (>300 mg/g), 2.43 (1.70-3.50); carotid-femoral pulse-wave velocity, 1.07 m/s (1.03-1.11 m/s); common carotid intima-media thickness, 2.57 mm (1.64-4.00 mm); left ventricular hypertrophy, 2.08 (1.21-3.57); and atrial fibrillation, 3.55 (2.02-6.25). Thus, the prevalence of resistant hypertension in Brazil is high and associated with subclinical markers of end-organ cardiovascular damage. |
11,350 | Insights into the problem of alarm fatigue with physiologic monitor devices: a comprehensive observational study of consecutive intensive care unit patients. | Physiologic monitors are plagued with alarms that create a cacophony of sounds and visual alerts causing "alarm fatigue" which creates an unsafe patient environment because a life-threatening event may be missed in this milieu of sensory overload. Using a state-of-the-art technology acquisition infrastructure, all monitor data including 7 ECG leads, all pressure, SpO(2), and respiration waveforms as well as user settings and alarms were stored on 461 adults treated in intensive care units. Using a well-defined alarm annotation protocol, nurse scientists with 95% inter-rater reliability annotated 12,671 arrhythmia alarms.</AbstractText>A total of 2,558,760 unique alarms occurred in the 31-day study period: arrhythmia, 1,154,201; parameter, 612,927; technical, 791,632. There were 381,560 audible alarms for an audible alarm burden of 187/bed/day. 88.8% of the 12,671 annotated arrhythmia alarms were false positives. Conditions causing excessive alarms included inappropriate alarm settings, persistent atrial fibrillation, and non-actionable events such as PVC's and brief spikes in ST segments. Low amplitude QRS complexes in some, but not all available ECG leads caused undercounting and false arrhythmia alarms. Wide QRS complexes due to bundle branch block or ventricular pacemaker rhythm caused false alarms. 93% of the 168 true ventricular tachycardia alarms were not sustained long enough to warrant treatment.</AbstractText>The excessive number of physiologic monitor alarms is a complex interplay of inappropriate user settings, patient conditions, and algorithm deficiencies. Device solutions should focus on use of all available ECG leads to identify non-artifact leads and leads with adequate QRS amplitude. Devices should provide prompts to aide in more appropriate tailoring of alarm settings to individual patients. Atrial fibrillation alarms should be limited to new onset and termination of the arrhythmia and delays for ST-segment and other parameter alarms should be configurable. Because computer devices are more reliable than humans, an opportunity exists to improve physiologic monitoring and reduce alarm fatigue.</AbstractText> |
11,351 | Benefit of cardiac sonography for estimating the early term survival of the cardiopulmonary arrest patients. | Cardiopulmonary resuscitation (CPR) is the most important intervention that connects the cardiopulmonary arrests (CPA), to life. Ultrasonography  (USG) is used to detect the presence of cardiac activity during CPR.</AbstractText>Files of the patiens, admitted to Kayseri Training and Research Hospital during one calendar year (2011) and suffered CPA were retrospectively evaluated by using hospital information management system. Patients enrolled in the study should have arrival electrocardiogram and cardiac ultrasound performed and  recorded.</AbstractText>A total of 410 patients were included in the study. When we examined the cardiac rhythm on arrival, 290 patients (70.7%) had asystole, 45 (11%) patients had ventricular fibrillation/ pulseless ventricular tachycardia (VF/pVT) and 75 (18.3%) patients had pulseless electrical activity (PEA). Twenty-four hour survival rates of the groups that the cardiac activity was detected with USG on arrival to the Emergency Department were: 2 patients in asystole group,  35 patients in VF/pVT group and  44 patients in PEA group.</AbstractText>Usage of USG during CPR in order to evaluate cardiac contractility, increases the success rate of accomplished CPR.</AbstractText> |
11,352 | Left atrial function measured by cardiac magnetic resonance imaging in patients with heart failure: clinical associations and prognostic value. | Left atrial (LA) volume is an important marker of cardiac dysfunction and cardiovascular outcome in heart failure (HF), but LA function is rarely measured.</AbstractText>Left atrial emptying function (LAEF), its clinical associations and prognostic value was studied in outpatients referred with suspected HF who were in sinus rhythm and had cardiac magnetic resonance imaging (CMRI). Heart failure was defined as relevant symptoms and signs with either a left ventricular ejection fraction (LVEF) <50% or amino-terminal pro-B-type natriuretic peptide (NTproBNP) >400 pg/mL (or >125 pg/mL if taking loop diuretics).</AbstractText>Of 982 patients, 664 fulfilled the HF criteria and were in sinus rhythm. The median (interquartile range, IQR) LAEF was 42 (31-51)% and 55 (48-61)% in patients with and without HF (P < 0.001). Patients with HF in the lowest quartile of LAEF (23%; IQR: 17-28%) had lower LV and right ventricular (RV) EF, and greater LV and RV mass and higher plasma NTproBNP than those in the highest quartile of LAEF (56%; IQR: 53-61%). Log[LAEF] and log[NTproBNP] were inversely correlated (r = -0.410, P < 0.001). During a median follow-up of 883 (IQR: 469-1626) days, 394 (59%) patients with HF died or were admitted with HF and 101 (15%) developed atrial fibrillation (AF). In a multivariable Cox model, increasing LAEF, but not LVEF, was independently associated with survival (HR for 10% change: 0.81 (95%CI: 0.73-0.90), P = <0.001). Increasing age and decreasing LAEF predicted incident AF.</AbstractText>In patients with HF, LAEF predicts adverse outcome independently of other measures of cardiac dysfunction.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
11,353 | [Effect of danlou tablet on arrhythmia model rats induced by transient myocardial ischemia/ reperfusion]. | To explore the effect of Danlou Tablet (DT) on arrhythmia model rats induced by transient myocardial ischemia/reperfusion (I/R).</AbstractText>Totally 45 healthy Wistar rats were randomly divided into 3 groups, the sham-operation group, the model group, and the DT group, 15 in each group. Rats in the sham-operation group and the model group were administered with distilled water by gastrogavage at the daily dose of 0.1 mL/kg. Rats in the DT group was administered with 0.53 g/mL DT suspension by gastrogavage at the daily dose of 0.1 mL/kg. All medication was lasted for 10 successive days. The myocardial I/R experiment was performed at 1 h after the last gastrogavage. ECG was performed before ligation and at I/R. The jugular arterial blood pressure of all rats was measured during the whole course. ST segment changes were observed at each time point of I/R. The ventricular fibrillation, the premature ventricular, the number and the duration of ventricular tachycardia within 30 min reperfusion were also observed. Activities of Na(+)-K+ ATPase and Ca2+ ATPase in the myocardium homogenate were detected as well.</AbstractText>The jugular arterial blood pressure and the heart rate were slightly lower in the DT group than in the model group, but with no statistical difference (P > 0.05). Compared with the sham-operation group, the degree of ST segment was obviously elevated in the model group at 0, 5, and 7 min (P < 0.05). It was significantly lower in the DT group than in the model group (P < 0.01). ST seg ment was more elevated at 5 min than at 0 min in the model group, but the degree of ST segment elevation was still obviously lower in the DT group than in the model group (P < 0.05). There was no statistical difference in the degree of ST segment elevation at 7 min between the two groups (P > 0.05). At 0 min when the decrement of ST segment exceeded one half the ischemia, there was no statistical difference in the degree of myocardial ischemia between the model group and the DT group (P > 0.05). Compared with the model group, the incidence of fatal and nonfatal ventricular fibrillation, the frequency and duration of ventricular tachycardia and premature ventricular beats were obviously lessened, and activities of Na(+)-K+ ATPase and Ca(2+)-ATPase increased (all P < 0.05).</AbstractText>DT could significantly protect arrhythmias induced by transient I/R. Its effect might be related to lowering the degree of myocardial ischemia, and increasing ion transport channel related enzyme activities.</AbstractText> |
11,354 | Genetic, clinical and pharmacological determinants of out-of-hospital cardiac arrest: rationale and outline of the AmsteRdam Resuscitation Studies (ARREST) registry. | Out-of-hospital cardiac arrest (OHCA) is a major public health problem. Recognising the complexity of the underlying causes of OHCA in the community, we aimed to establish the clinical, pharmacological, environmental and genetic factors and their interactions that may cause OHCA.</AbstractText>We set up a large-scale prospective community-based registry (AmsteRdam Resuscitation Studies, ARREST) in which we prospectively include all resuscitation attempts from OHCA in a large study region in the Netherlands in collaboration with Emergency Medical Services. Of all OHCA victims since June 2005, we prospectively collect medical history (through hospital and general practitioner), and current and previous medication use (through community pharmacy). In addition, we include DNA samples from OHCA victims with documented ventricular tachycardia/fibrillation during the resuscitation attempt since July 2007. Various study designs are employed to analyse the data of the ARREST registry, including case-control, cohort, case only and case-cross over designs.</AbstractText>We describe the rationale, outline and potential results of the ARREST registry. The design allows for a stable and reliable collection of multiple determinants of OHCA, while assuring that the patient, lay-caregiver or medical professional is not hindered in any way. Such comprehensive data collection is required to unravel the complex basis of OHCA. Results will be published in peer-reviewed journals and presented at relevant scientific symposia.</AbstractText> |
11,355 | Effects of β-blocker therapy on electrocardiographic and echocardiographic characteristics of left ventricular noncompaction. | Left ventricular noncompaction (LVNC) is a cardiomyopathy with hypertrabeculation of the LV, often complicated by heart failure, arrhythmia and thromboembolic events. The features of LVNC are still incompletely characterized due to its late recognition as clinically relevant condition. The aims of this study were to describe echocardiographic and electrophysiologic characteristics of LVNC patients and to assess the effects of chronic β-blocker treatment. Study patients (n = 20; 42.5 [36.3; 52.5] years; 12 men) exhibited reduced LV ejection fraction (median LVEF = 32 %) and an increased LV mass of 210 g. Sinus rhythm was present in 19 patients, whereas one patient was in atrial fibrillation. Baseline heart rate was 77.5 beats per minute. Left bundle branch block was detected in five cases. In a subgroup of patients receiving β-blocker therapy (n = 17), LV mass was reduced from 226 [178; 306] g to 220 [169; 254] g (p = 0.007) at 13 ± 6 months follow-up. By contrast, a subgroup of three patients that were not treated with an anti-β-adrenergic agent showed LV mass increase from 180 [169; 197] g to 199 [185; 213] g (p = 0.023). LVEF and electrocardiographic parameters were not significantly modulated during chronic β-blocker treatment. There was no sustained symptomatic ventricular tachyarrhythmia, thromboembolic event or death in either group. In conclusion, this study reveals reduction of LV mass among LVNC patients during β-blocker therapy. Effects of β-blocker treatment in LVNC require validation in prospective controlled studies. |
11,356 | Maximal electrogram attenuation recorded from mini electrodes embedded on 4.5-mm irrigated and 8-mm nonirrigated catheters signifies lesion maturation. | The electrograms (EGMs) recorded from mini electrodes (ME) placed on the tip of the ablation electrode allow more precise EGM monitoring during lesion formation. Our objective was to define the lesion boundaries and extracardiac injuries resulting from 60-second RF application versus RF application time titrated to maximal attenuation of the ME EGM in the atria and ventricles using 4.5-mm irrigated and 8-mm catheters.</AbstractText>RF lesions were placed in both atria and ventricles in 13 (30-35 kg) canines; 6 (4.5-mm OI) and 7 (8 mm). The RF application time was fixed at 60 seconds or terminated at maximal ME EGM amplitude attenuation.</AbstractText>Pre/postablation pacing thresholds, EGM amplitudes, and lesion dimensions were not significantly different between maximal EGM attenuation and 60-second RF application using either catheter. Atrial lesion transmurality was also similar for both catheters and groups 91.2% (4.5 mm) and 96% (8 mm) when the RF was titrated to the maximal EGM attenuation and 94.2% (4.5 mm) and 95% (8 mm) with 60-second RF. The 60-second RF ablation, however, presented with significant extracardiac injuries to the lungs and esophagus, along with char formation. Deep ventricular lesions were noted with maximal EGM attenuation that were not different from the 60-second RF ablation.</AbstractText>Titration of the RF application time to the maximal EGM attenuation based on the ME recordings represents atrial lesion maturation and deep ventricular lesions. Prolonging the RF application results in greater extracardiac injury and char formation without increasing lesion size.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,357 | [Effects of intracellular calcium alteration on SK currents in atrial cardiomyocytes from patients with atrial fibrillation]. | SK channels are existed in hearts of mouse, rat, and human. Biochemical evidence indicates that SK2 channels are expressed more in atrial than in ventricular tissue. SK channels are highly sensitive to the calcium concentration of the pipette solution. In the present study, performed whole-cell patch clamp was used to detect the calcium sensitivity of small conductance Ca(2+)-activated K+ channels (SK) currents between sinus ryhthm (SR) and auricular fibrillation (AF).</AbstractText>The patients who accepted cardiopulmonary bypass were divided into two groups: 21 patients with SR and 8 patients with AF. The enzymatic dissociation method was improved according to the previous research by our lab. The performed whole cell patch-clamp technique was used to record SK2 currents in both SR and AF groups at room temperature.</AbstractText>The SK2 current density was (-2.92 +/- 0.35) pA/pF in SR group (n = 6) vs (-6.83 +/- 0.19) pA/pF in AF group at -130 mV (n = 3, P < 0.05). In SR group, the SK2 current densities in calcium concentration of the pipette solution are (-1.43 +/- 0.33) pA/pF (n = 7), (-2.92 +/- 0.35) pA/pF (n = 6), (-10.11 +/- 2.15) pA/pF (n = 8, P < 0.05); In AF group, the SK2 current densities are (-2.17 +/- 0.40) pA/pF (n = 4), (-6.83 +/- 0.19) pA/pF (n = 3), (-14.47 +/- 2.89 pA/pF) (n = 4, P < 0.05).</AbstractText>The SK2 currents recorded in this experiment are voltage-independent, inwardly rectifying and apamin-sensitive. When the calcium concentration of the pipette solution is 5 x 10(-7) mol/L, SK2 current density in AF group are significantly larger than those in SR group. It suggests that SK currents involve the cardiomyocytes electric remodeling in AF. In AF group, the SK2 currents are more sensitive to free calcium ion. It shows that the increased sensitivity of SK2 currents to the calcium contribute to the occurrence and maintenance of AF.</AbstractText> |
11,358 | Echocardiographic measures of cardiac structure and function are associated with risk of atrial fibrillation in blacks: the Atherosclerosis Risk in Communities (ARIC) study. | Several studies have examined the link between atrial fibrillation (AF) and various echocardiographic measures of cardiac structure and function in whites and other racial groups but not in blacks. Exploring AF risk factors in blacks is important given that the lower incidence of AF in this racial group despite higher risk factors, is not completely explained.</AbstractText>We examined the association of echocardiographic measures with AF incidence in 2283 blacks (64.5% women, mean age 58.8 years) free of diagnosed AF and enrolled in the Jackson cohort of Atherosclerosis Risk in Communities (ARIC) study, a prospective study of cardiovascular disease. Echocardiography was performed in 1993-1995, and incident AF was determined by electrocardiograms at a follow-up study exam, hospitalization discharge codes and death certificates through the end of 2009. Cox proportional hazards regression was used to estimate hazard ratios and 95% confidence intervals for AF associated with the echocardiographic measures, adjusting for age, sex, and known AF risk factors.</AbstractText>During an average follow-up of 13.5 years, 191 (8.4%) individuals developed AF. Left ventricular (LV) internal diameter 2-D (diastole) and percent fractional shortening of LV diameter displayed a U-shaped relationship with risk of AF, while left atrial diameter displayed a J-shaped nonlinear association. LV mass index was associated positively with AF. E/A ratio <0.7 or >1.5 and ejection fraction (EF <50%) were also associated with higher AF risk. These measures improved risk stratification for AF in addition to traditional risk factors, although not significantly {C-statistic of 0.767 (0.714-0.819) vs. 0.744 (0.691-0.797)}.</AbstractText>In a community-based population of blacks, echocardiographic measures of cardiac structure and function are significantly associated with an increased risk of AF.</AbstractText> |
11,359 | Antiarrhythmic and electrophysiologic effects of flecainide on acutely induced atrial fibrillation in healthy horses. | Only few pharmacologic compounds have been validated for treatment of atrial fibrillation (AF) in horses. Studies investigating the utility and safety of flecainide to treat AF in horses have produced conflicting results, and the antiarrhythmic mechanisms of flecainide are not fully understood.</AbstractText>To study the potential of flecainide to terminate acutely induced AF of short duration (≥ 15 minutes), to examine flecainide-induced changes in AF duration and AF vulnerability, and to investigate the in vivo effects of flecainide on right atrial effective refractory period, AF cycle length, and ventricular depolarization and repolarization.</AbstractText>Nine Standardbred horses. Eight received flecainide, 3 were used as time-matched controls, 2 of which also received flecainide.</AbstractText>Prospective study. The antiarrhythmic and electrophysiologic effects of flecainide were based on 5 parameters: ability to terminate acute pacing-induced AF (≥ 15 minutes), and drug-induced changes in atrial effective refractory period, AF duration, AF vulnerability, and ventricular depolarization and repolarization times. Parameters were assessed at baseline and after flecainide by programmed electrical stimulation methods.</AbstractText>Flecainide terminated all acutely induced AF episodes (n = 7); (AF duration, 21 ± 5 minutes) and significantly decreased the AF duration, but neither altered atrial effective refractory period nor AF vulnerability significantly. Ventricular repolarization time was prolonged between 8 and 20 minutes after initiation of flecainide infusion, but no ventricular arrhythmias were detected.</AbstractText>Flecainide had clear antiarrhythmic properties in terminating acute pacing-induced AF, but showed no protective properties against immediate reinduction of AF. Flecainide caused temporary prolongation in the ventricular repolarization, which may be a proarrhythmic effect.</AbstractText>Copyright © 2014 by the American College of Veterinary Internal Medicine.</CopyrightInformation> |
11,360 | Clinical role of atrial arrhythmias in patients with arrhythmogenic right ventricular dysplasia. | The clinical role of atrial fibrillation/atrial flutter (AF-AFl) and variables predicting these arrhythmias are not well defined in patients with arrhythmogenic right ventricular dysplasia (ARVD). We hypothesized that transthoracic echocardiography (TTE) and 12-lead electrocardiography (ECG) would be helpful in predicting AF-AFl in these patients. METHODS AND RESULTS: ECGs and TTEs of 90 patients diagnosed with definite or borderline ARVD (2010 Task Force Criteria) were analyzed. Data were compared in (1) patients with AF-AFl and (2) all other patients. A total of 18 (20%) patients experienced AF-AFl during a median follow-up of 5.8 years (interquartile range 2.0-10.4). Kaplan-Meier analysis revealed reduced times to AF-AFl among patients with echocardiographic RV fractional area change <27% (P<0.001), left atrial diameter ≥24.4 mm/m(2)(parasternal long-axis, P=0.001), and right atrial short-axis diameter ≥22.1 mm/m(2)(apical 4-chamber view, P=0.05). From all ECG variables, P mitrale conferred the highest hazard ratio (3.37, 95% confidence interval 0.92-12.36, P=0.067). Five patients with AF-AFl experienced inappropriate implantable cardioverter-defibrillator (ICD) shocks compared with 4 without AF-AFl (36% vs. 9%, P=0.03). AF-AFl was more prevalent in heart-transplant patients and those who died of cardiac causes (56% vs. 16%, P=0.014).</AbstractText>AF-AFl is associated with inappropriate ICD shocks, heart transplantation, and cardiac death in patients with ARVD. Evidence of reduced RV function and atrial dilation helps to identify the ARVD patients at increased risk for AF-AFl.</AbstractText> |
11,361 | Ectopic visceral fat: a clinical and molecular perspective on the cardiometabolic risk. | Worldwide, cardiovascular diseases (CVDs) are a leading cause of mortality. While in many westernized societies there has been a decrease prevalence of smoking and that a special emphasis has been put on the urgency to control the, so called, classical risk factors, it is more and more recognized that there remains a residual risk, which contributes to the development of CVDs. Imaging studies conducted over two decades have highlighted that the accumulation of ectopic visceral fat is associated with a plethora of metabolic dysfunctions, which have complex and intertwined interactions and participate to the development/progression/events of many cardiovascular disorders. The contribution of visceral ectopic fat to the development of coronary artery disease (CAD) is now well established, while in the last several years emerging evidence has pointed out that accumulation of harmful ectopic fat is associated with other cardiovascular disorders such as calcific aortic valve disease (CAVD), atrial fibrillation and left ventricular dysfunction. We review herein the key molecular processes linking the accumulation of ectopic fat to the development of CVDs. We have attempted, whenever possible, to use a translational approach whereby the pathobiology processes are linked to clinical observations. |
11,362 | Cardiac arrhythmias and sleep-disordered breathing in patients with heart failure. | The relationship between heart failure (HF), sleep-disordered breathing and cardiac arrhythmias is complex and poorly understood. Whereas the frequency of predominantly obstructive sleep apnea in HF patients is low and similar or moderately higher to that observed in the general population, central sleep apnea (CSA) has been observed in approximately 50% of HF patients, depending on the methods used to detect CSA and patient selection. Despite this high prevalence, it is still unclear whether CSA is merely a marker or an independent risk factor for an adverse prognosis in HF patients and whether CSA is associated with an increased risk for supraventricular as well as ventricular arrhythmias in HF patients. The current review focuses on the relationship between CSA and atrial fibrillation as the most common atrial arrhythmia in HF patients, and on the relationship between CSA and ventricular tachycardia and ventricular fibrillation as the most frequent cause of sudden cardiac death in HF patients. |
11,363 | Effectiveness of antitachycardia pacing therapy after primary prophylaxis implantation of implantable defibrillators in coronary artery disease patients. | Effectiveness of implantable defibrillators (ICD) has been proven with large randomized trials. Unfortunately, ICD discharge is painful and potentially threatening for the patient despite its life saving effects. We analyzed influence of the clinical parameters present before implantation on the effectiveness of antitachycardia pacing therapy (ATP) in terminating ventricular tachycardia (VT) slower than 200 bpm in the coronary artery disease patients with prophylactic implanted ICD in a single centre retrospective trial.</AbstractText><AbstractText Label="PATIENTS/METHODS" NlmCategory="METHODS">We analyzed 121 consecutive coronary disease patients with ICD implanted in primary prophylaxis between 2001 and 2007, with the mean age of 62 ± 10 years. The mean follow-up was 876 ± 538 days.</AbstractText>32 of them had VT. In 27 persons (84.4%) at least one ATP attempt terminate VT. ATP was always successful in 21 patients. We analyzed age, sex, LVEF, NYHA class, widening of QRS complex, atrial fibrillation, type of myocardial infarction or diabetes. There were no significant differences in clinical features between patients with successful and unsuccessful ATP therapy.</AbstractText>High effectiveness of ATP was shown in this group. There were no clinical factors indicating success of this type of therapy. That could justify programming ATP as the first line therapy in the VT zone in primary prophylaxis coronary artery disease patients to reduce application of shock therapy. It should be possible to apply a single mode of programming when discharging patients after the implantation procedure regardless of the patient's clinical condition. This could help to control and programme the devices, thus reducing the risk of errors.</AbstractText>Copyright © 2014. Published by Elsevier Urban & Partner Sp. z o.o.</CopyrightInformation> |
11,364 | Patient-centric blood pressure-targeted cardiopulmonary resuscitation improves survival from cardiac arrest. | Although current resuscitation guidelines are rescuer focused, the opportunity exists to develop patient-centered resuscitation strategies that optimize the hemodynamic response of the individual in the hopes to improve survival.</AbstractText>To determine if titrating cardiopulmonary resuscitation (CPR) to blood pressure would improve 24-hour survival compared with traditional CPR in a porcine model of asphyxia-associated ventricular fibrillation (VF).</AbstractText>After 7 minutes of asphyxia, followed by VF, 20 female 3-month-old swine randomly received either blood pressure-targeted care consisting of titration of compression depth to a systolic blood pressure of 100 mm Hg and vasopressors to a coronary perfusion pressure greater than 20 mm Hg (BP care); or optimal American Heart Association Guideline care consisting of depth of 51 mm with standard advanced cardiac life support epinephrine dosing (Guideline care). All animals received manual CPR for 10 minutes before first shock. Primary outcome was 24-hour survival.</AbstractText>The 24-hour survival was higher in the BP care group (8 of 10) compared with Guideline care (0 of 10); P = 0.001. Coronary perfusion pressure was higher in the BP care group (point estimate +8.5 mm Hg; 95% confidence interval, 3.9-13.0 mm Hg; P < 0.01); however, depth was higher in Guideline care (point estimate +9.3 mm; 95% confidence interval, 6.0-12.5 mm; P < 0.01). Number of vasopressor doses before first shock was higher in the BP care group versus Guideline care (median, 3 [range, 0-3] vs. 2 [range, 2-2]; P = 0.003).</AbstractText>Blood pressure-targeted CPR improves 24-hour survival compared with optimal American Heart Association care in a porcine model of asphyxia-associated VF cardiac arrest.</AbstractText> |
11,365 | E-NTPDase1/CD39 modulates renin release from heart mast cells during ischemia/reperfusion: a novel cardioprotective role. | Ischemia/reperfusion (I/R) elicits renin release from cardiac mast cells (MC), thus activating a local renin-angiotensin system (RAS), culminating in ventricular fibrillation. We hypothesized that in I/R, neurogenic ATP could degranulate juxtaposed MC and that ecto-nucleoside triphosphate diphosphohydrolase 1/CD39 (CD39) on MC membrane could modulate ATP-induced renin release. We report that pharmacological inhibition of CD39 in a cultured human mastocytoma cell line (HMC-1) and murine bone marrow-derived MC with ARL67156 (100 µM) increased ATP-induced renin release (≥2-fold), whereas purinergic P2X7 receptors (P2X7R) blockade with A740003 (3 µM) prevented it. Likewise, CD39 RNA silencing in HMC-1 increased ATP-induced renin release (≥2-fold), whereas CD39 overexpression prevented it. Acetaldehyde, an I/R product (300 µM), elicited an 80% increase in ATP release from HMC-1, in turn, causing an autocrine 20% increase in renin release. This effect was inhibited or potentiated when CD39 was overexpressed or silenced, respectively. Moreover, P2X7R silencing prevented ATP- and acetaldehyde-induced renin release. I/R-induced RAS activation in ex vivo murine hearts, characterized by renin and norepinephrine overflow and ventricular fibrillation, was potentiated (∼2-fold) by CD39 inhibition, an effect prevented by P2X7R blockade. Our data indicate that by regulating ATP availability at the MC surface, CD39 modulates local renin release and thus, RAS activation, ultimately exerting a cardioprotective effect. |
11,366 | Long-term follow-up in AV junction ablation via the SVC in patients undergoing concurrent device implantation: a single center experience. | Ablation of the atrioventricular junction (AVJ) combined with pacemaker implantation (the "ablate and pace" approach) has been an effective treatment strategy for patients with atrial fibrillation (AF) when rate control is the goal of therapy and when rapid ventricular rates during AF is refractory to pharmacologic therapy.</AbstractText>This report describes the feasibility and safety of catheter ablation of AVJ via a superior vena cava (SVC) approach performed during concurrent pacemaker or defibrillator implantation.</AbstractText>A total of 170 consecutive patients with drug-refractory AF underwent combined AVJ ablation and pacemaker or defibrillator implantation using the axillary or subclavian venous approach. The acute and long-term success of achieving complete atrioventricular (AV) block, the impact of the ablation procedure on the total procedure time and fluoroscopy duration, and procedural complications were evaluated.</AbstractText>A dual-chamber device in 61% of patients and biventricular device in 39% patients. Catheter ablation of the AVJ was acutely successful in 166 patients (97.6%). The mean procedure time of the AVJ ablation was 7.0 ± 3.3 minutes and the mean fluoroscopy time during the ablation procedure was 3.1 ± 3.2 minutes. The average duration of RF energy application required to achieve complete AV block was 129 ± 65 seconds. Procedural complications were observed in seven patients. Complete AV block persisted in 96% of patients during a mean follow-up of 26 ± 16 months.</AbstractText>Catheter ablation of the AVJ can be performed successfully and safely using the SVC approach in patients undergoing concurrent device implantation, and it may offer several advantages over the conventional femoral approach.</AbstractText>© 2014 Wiley Periodicals, Inc.</CopyrightInformation> |
11,367 | Regional pericarditis status post cardiac ablation: a case report. | Regional pericarditis is elusive and difficult to diagnosis. Healthcare providers should be familiar with post-cardiac ablation complications as this procedure is now widespread and frequently performed. The management of regional pericarditis differs greatly from that of acute myocardial infarction.</AbstractText>A 52 year-old male underwent atrial fibrillation ablation and developed severe mid-sternal chest pain the following day with electrocardiographic findings suggestive of acute myocardial infarction, and underwent coronary angiography, a left ventriculogram, and 2D transthoracic echocardiogram, all of which were unremarkable without evidence of obstructive coronary disease, wall motion abnormalities, or pericardial effusions. Ultimately, the patient was diagnosed with regional pericarditis. After diagnosis, the patient's presenting symptoms resolved with treatment including nonsteroidal anti-inflammatory agents and colchicine.</AbstractText>This is the first reported case study of regional pericarditis status post cardiac ablation. Electrocardiographic findings were classic for an acute myocardial infarction; however, coronary angiography and left ventriculogram demonstrated no acute coronary occlusion or ventricular wall motion abnormalities. Healthcare professionals must remember that the electrocardiographic findings in pericarditis are not always classic and that pericarditis can occur status post cardiac ablation.</AbstractText> |
11,368 | A systematic review of the association between obstructive sleep apnea and ventricular arrhythmias. | Obstructive sleep apnea (OSA) is an independent risk factor for sudden cardiac death. The aim of this review was to study the relationship between OSA and ventricular arrhythmias.</AbstractText>PubMed, Medline, and Cochrane databases were searched with MESH headings to find studies linking OSA and ventricular arrhythmias including ventricular ectopy, ventricular tachycardia (VT), and ventricular fibrillation (VF). Studies were graded by a scoring system, and an attempt was made to pool data.</AbstractText>There were no matched cohort or case control studies to study the association between OSA and ventricular arrhythmias. Given data heterogeneity, pooling and meta-analysis of data were not possible. An attempt was made to judge the quality of evidence and present a systematic review. Patients with OSA were noted to have higher odds of ventricular ectopy, and were at a higher risk for ventricular arrhythmias. Associations included higher QTc dispersion and HR variability. We did not, however, find any clear evidence for a direct correlation between increased apnea hypopnea index and increased VT or VF.</AbstractText>Pooling and meta-analysis of studies linking OSA and ventricular arrhythmias were not possible due to heterogeneity of data. In a systemic review of studies, patients with OSA were noted to have higher odds of ventricular ectopy and arrhythmias. A single study showed that CPAP may help lower arrhythmogenicity; however, it was unclear if CPAP lowered the risk of VT. Further research should focus on studying the association of OSA and causes of sudden cardiac death, including ventricular arrhythmias.</AbstractText> |
11,369 | Prognostic significance of atrial fibrillation and severity of symptoms of heart failure in patients with low gradient aortic stenosis and preserved left ventricular ejection fraction. | The aims of this study were to investigate the clinical outcomes of patients with low-gradient aortic stenosis despite preserved left ventricular ejection fraction and to assess reliable prognostic clinical-instrumental features in patients experiencing or not experiencing aortic valve replacement (AVR). Clinical-laboratory and echocardiographic data from 167 patients (median age 78 years, interquartile range 69 to 83) with aortic valve areas <1.0 cm(2), mean gradients ≤30 mm Hg, and preserved left ventricular ejection fraction (≥55%), enrolled from 2005 to 2010, were analyzed. During a mean follow-up period of 44 ± 23 months, 33% of patients died. On multivariate analysis, independent predictors of death were baseline New York Heart Association functional class III or IV (hazard ratio 2.16, p = 0.038) and atrial fibrillation (hazard ratio 2.00, p = 0.025). Conversely, AVR was protective (hazard ratio 0.25, p = 0.01). The magnitude of the protective effect of AVR seemed to be relatively more important in patients with atrial fibrillation than in those in sinus rhythm, independently of the severity of symptoms. Age >70 years showed a trend toward being a prognostic predictor (p = 0.082). In conclusion, in patients with low-gradient aortic stenosis despite a preserved left ventricular ejection fraction, AVR was strongly correlated with a better prognosis. Patients with atrial fibrillation associated with advanced New York Heart Association class had the worst prognosis if treated medically but at the same time a relative better benefit from surgical intervention. |
11,370 | [Efficacy and safety of early rapid infusion of icy normal saline in patients after cardiopulmonary resuscitation]. | To assess the feasibility, safety, and effectiveness of early rapid icy normal saline infusion to attain mild hypothermia in cardiac arrest patients.</AbstractText>A single-center prospective randomized controlled trial was conducted. From March 2011 to October 2013, patients who had recovery of spontaneous circulation (ROSC) after cardiopulmonary resuscitation (CPR) in Beijing Daxing District People's Hospital were randomly divided into two groups. In icy normal saline group, patients received a rapid infusion of 1 000 mL of 4 centigrade normal saline intravenously to attain a mild hypothermia. In the control group, the patients were treated with ice bag on head, and axillary temperature was monitored. For all patients, rectal temperature was measured and recorded immediately and 1 hour later. The occurrence of pulmonary edema on initial chest X-ray at 6 hours, occurrence of tremor within 48 hours, ventricular fibrillation recurring within 48 hours, and consciousness or death within 14 days were recorded.</AbstractText>A total of 45 patients were enrolled, including 23 patients in icy normal saline group and 22 in control group. The patients in icy normal saline group had a rectal temperature descended from (36.7 ± 0.9) centigrade to (34.9 ± 0.7) centigrade 1 hour later, while the patients in control group had a rectal temperature risen from (36.5 ± 1.0) centigrade to (37.9 ± 0.9) centigrade 1 hour later. There was significant difference in rectal temperature between two groups (t=2.228, P=0.031). The number of patients who successfully awaken within 14 days in ice normal saline group was significantly larger than that in control group (13 cases vs. 7 cases, χ² = 65.710, P=0.021). There was no statistical difference in the occurrence of acute pulmonary edema (4 cases vs. 6 cases), tremor (2 cases vs. 0 case), ventricular fibrillation recurrence (4 cases vs. 5 cases) and death within 14 days(11 cases vs. 12 cases, all P>0.05).</AbstractText>The study shows that early rapid i.v. infusion of 4 centigrade normal saline is feasible, safe and effective for cerebral resuscitation.</AbstractText> |
11,371 | Detailed characterization of microRNA changes in a canine heart failure model: Relationship to arrhythmogenic structural remodeling. | Heart failure (HF) causes left-atrial (LA) and left-ventricular (LV) remodeling, with particularly-prominent changes in LA that create a substrate for atrial fibrillation (AF). MicroRNAs (miRs) are potential regulators in cardiac remodeling. This study evaluated time-dependent miR expression-changes in LA and LV tissue, fibroblasts and cardiomyocytes in experimental HF. HF was induced in dogs by ventricular tachypacing (varying periods, up to 2weeks). Following screening-microarray, 15 miRs were selected for detailed real-time qPCR assay. Extracellular matrix mRNA-expression was assessed by qPCR. Tachypacing time-dependently reduced LV ejection-fraction, increased LV-volume and AF-duration, and caused tissue-fibrosis with LA changes greater than LV. Tissue miR-expression significantly changed in LA for 10 miRs; in LV for none. Cell-selective analysis showed significant time-dependent changes in LA-fibroblasts for 10/15 miRs, LV-fibroblasts 8/15, LA-cardiomyocytes in 6/15 and LV-cardiomyocytes 3/15. Cell-expression specificity did not predict cell-specificity of VTP-induced expression-changes, e.g. 4/6 cardiomyocyte-selective miRs changed almost exclusively in fibroblasts (miR-1, miR-208b, miR133a/b). Thirteen miRs directly implicated in fibrosis/extracellular-matrix regulation were prominently changed: 9/13 showed fibroblast-selective alterations and 5/13 LA-selective. Multiple miRs changed in relation to associated extracellular-matrix targets. Experimental HF causes tissue and cell-type selective, time-dependent changes in cardiac miR-expression. Expression-changes are greater in LA versus LV, and greater in fibroblasts than cardiomyocytes, even for most cardiomyocyte-enriched miRs. This study, the first to examine time, chamber and cell-type selective changes in an experimental model of HF, suggests that multiple miR-changes underlie the atrial-selective fibrotic response and emphasize the importance of considering cell-specificity of miR expression-changes in cardiac remodeling paradigms. |
11,372 | Incidence, outcome, and attributable resource use associated with pulmonary and cardiac complications after major small and large bowel procedures. | Complications increase the costs of care of surgical patients. We studied the Premier database to determine the incidence and direct medical costs related to pulmonary complications and compared it to cardiac complications in the same cohort.</AbstractText>We identified 45,969 discharges in patients undergoing major bowel procedures. Postoperative pulmonary and cardiac complications were identified through the use of International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) codes and through the use of daily resource use data. Pulmonary complications included pneumonia, tracheobronchitis, pleural effusion, pulmonary failure, and mechanical ventilation more than 48 h after surgery. Cardiac complications included ventricular fibrillation, acute myocardial infarction, cardiogenic shock, cardiopulmonary arrest, transient ischemia, premature ventricular contraction, and acute congestive heart failure.</AbstractText>Postoperative pulmonary complications (PPC) or postoperative cardiac complications (PCC) were present in 22% of cases; PPC alone was most common (19.0%), followed by PPC and PCC (1.8%) and PCC alone (1.2%). The incremental cost of PPC is large ($25,498). In comparison, PCC alone only added $7,307 to the total cost.</AbstractText>The current study demonstrates that postoperative pulmonary complications represent a significant source of morbidity and incremental cost after major small intestinal and colon surgery and have greater incidence and costs than cardiac complications alone. Therefore, strategies to reduce the incidence of these complications should be targeted as means of improving health and bending the cost curve in health care.</AbstractText> |
11,373 | ECG Case of the Month. Out-of-Hospital Cardiac Arrest. DIAGNOSIS: Atrial fibrillation with a rapid ventricular response (150 beats/minute) and right bundle branch block. | A muscular-appearing 50-year-old man was found down in his home by family members. Paramedics documented pulseless electrical activity and began cardiopulmonary resuscitation that included placement of an endotracheal tube. The resuscitation was continued in the hospital emergency department (ED), and after 20 minutes, an arterial pulse returned. An electrocardiogram (ECG) was obtained (Figure 1). Meanwhile, a past history established that the patient was a personal trainer who seemed fit and healthy until 10 days earlier, when he came to the ED because he had begun to lose his balance and fall frequently. Computed tomography (CT) at that time revealed lytic lesions in the fifth lumbar vertebra and extensive retroperitoneal lymphadenopathy involving the aortic, iliac, and obturator chains and the perirectal region. Arrangements had then been made for outpatient workup of a presumed malignancy. |
11,374 | Blood stasis secondary to heart failure forms warfarin-resistant left atrial thrombus. | Anticoagulants such as warfarin are recommended for patients with atrial fibrillation (AF) to decrease stroke risk associated with thrombus formation in the left atrium (LA). In a subgroup of patients, however, warfarin is unable to prevent LA thrombus formation at therapeutic doses. This study characterized the clinical and echocardiographic features of patients having warfarin-resistant LA thrombus.Of the 1364 nonvalvular AF patients examined by transesophageal echocardiography, 431 received warfarin. A total of 10 patients (2.3% of warfarin-treated patients) exhibited LA thrombus formation even during warfarin treatment at a dose and duration sufficient for increasing the prothrombin time-international normalized ratio (PT-INR) to the therapeutic range for ≥ 30 days. Categorical regression analysis revealed that decreased LA appendage (LAA) flow velocity, greater LA spontaneous echocardiographic contrast (LASEC), and lower left ventricular ejection fraction (LVEF) significantly contributed to residual LA thrombus (P < 0.05 for all). Receiver operating characteristic (ROC) curve analysis indicated that higher right ventricular systolic pressure, which suggests LA pressure (area under curve, 0.85), LV mass index (0.81), and LA dimension (0.68), as well as lower LAA flow velocity (0.92) and LVEF (0.91) predicted warfarin resistant LA thrombus formation (all P < 0.05).These results suggest that blood stasis secondary to heart failure contributes to the formation of warfarin-resistant LA thrombus. We propose that therapies to increase LVEF should be administered together with warfarin for AF patients with heart failure to decrease stroke risk. |
11,375 | Atrial tachycardias following atrial fibrillation ablation. | One of the most important proarrhythmic complications after left atrial (LA) ablation is regular atrial tachycardia (AT) or flutter. Those tachycardias that occur after atrial fibrillation (AF) ablation can cause even more severe symptoms than those from the original arrhythmia prior to the index ablation procedure since they are often incessant and associated with rapid ventricular response. Depending on the method and extent of LA ablation and on the electrophysiological properties of underlying LA substrate, the reported incidence of late ATs is variable. To establish the exact mechanism of these tachycardias can be difficult and controversial but correlates with the ablation technique and in the vast majority of cases the mechanism is reentry related to gaps in prior ablation lines. When tachycardias occur, conservative therapy usually is not effective, radiofrequency ablation procedure is mostly successful, but can be challenging, and requires a complex approach. |
11,376 | Development of the subcutaneous implantable cardioverter-defibrillator for reducing sudden cardiac death. | Implantable cardioverter-defibrillators (ICDs) detect ventricular arrhythmias responsible for causing sudden cardiac arrest and then deliver a high-voltage defibrillation shock to terminate the arrhythmia and restore normal cardiac function. Conventional transveneous ICD (TV-ICD) systems require one or more leads to be implanted into the heart through the venous anatomy. While TV-ICDs are well tolerated by most patients, the invasive approach can be associated with severe complications, including systemic infection, cardiac injuries, and lead failures. An entirely subcutaneous ICD (S-ICD) system was developed as a less invasive alternative to TV-ICDs without requiring leads in or on the heart. The S-ICD system provides therapy with a left lateral pulse generator and parasternal electrode configuration that is placed under the skin outside the rib cage, resulting in a much lower risk profile. Advances in defibrillation research and far-field sensing combined to enable development of the commercial S-ICD system. An investigation device exemption (IDE) clinical investigation followed, with FDA approval in September 2012. Evaluation of the long-term performance of the S-ICD system continues, with two independent postmarket registries and a prospective randomized head-to-head trial versus the transvenous ICD. |
11,377 | Outcomes of implantable cardioverter-defibrillator use in patients with comorbidities: results from a combined analysis of 4 randomized clinical trials. | The aim of this study was to determine if the benefit of implantable cardioverter-defibrillators (ICDs) is modulated by medical comorbidity.</AbstractText>Primary prevention ICDs improve survival in patients at risk for sudden cardiac death. Their benefit in patients with significant comorbid illness has not been demonstrated.</AbstractText>Original, patient-level datasets from MADIT I (Multicenter Automatic Defibrillator Implantation Trial I), MADIT II, DEFINITE (Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation), and SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial) were combined. Patients in the combined population (N = 3,348) were assessed with respect to the following comorbidities: smoking, pulmonary disease, diabetes, peripheral vascular disease, atrial fibrillation, ischemic heart disease, and chronic kidney disease. The primary outcome was overall mortality, using the hazard ratio (HR) of time to death for patients receiving an ICD versus no ICD by extent of medical comorbidity, and adjusted for age, sex, race, left ventricular ejection fraction, use of antiarrhythmic drugs, beta-blockers, and angiotensin-converting enzyme inhibitors.</AbstractText>Overall, 25% of patients (n = 830) had <2 comorbid conditions versus 75% (n = 2,518) with significant comorbidity (≥2). The unadjusted hazard of death for patients with an ICD versus no ICD was significantly lower, but this effect was less for patients with ≥2 comorbidities (unadjusted HR: 0.71; 95% confidence interval: 0.61 to 0.84) compared with those with <2 comorbidities (unadjusted HR: 0.59; 95% confidence interval: 0.40 to 0.87). After adjustment, the benefit of an ICD decreased with increasing number of comorbidities (p = 0.004).</AbstractText>Patients with extensive comorbid medical illnesses may experience less benefit from primary prevention ICDs than those with less comorbidity; implantation should be carefully considered in sick patients. Further study of ICDs in medically complex patients is warranted.</AbstractText>Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,378 | Early eicosapentaenoic acid treatment after percutaneous coronary intervention reduces acute inflammatory responses and ventricular arrhythmias in patients with acute myocardial infarction: a randomized, controlled study. | We examined whether early loading of eicosapentaenoic acid (EPA) reduces clinical adverse events by 1 month, accompanied by a decrease in C-reactive protein (CRP) values in patients with acute myocardial infarction (MI).</AbstractText>Acute MI triggers an inflammatory reaction, which plays an important role in myocardial injury. EPA could attenuate the inflammatory response.</AbstractText>This prospective, open-label, blinded endpoint, randomized trial consisted of 115 patients with acute MI. They were randomly assigned to the EPA group (57 patients) and the control group (58 patients). After percutaneous coronary intervention (PCI), 1800 mg/day of EPA was initiated within 24h. The primary endpoint was composite events, including cardiac death, stroke, re-infarction, ventricular arrhythmias, and paroxysmal atrial fibrillation within 1 month.</AbstractText>Administration of EPA significantly reduced the primary endpoint within 1 month (10.5 vs 29.3%, p=0.01), especially the incidence of ventricular arrhythmias (7.0 vs 20.6%, p=0.03). Peak CRP values after PCI in the EPA group were significantly lower than those in the control group (median [interquartile range], 8.2 [5.6-10.2] mg/dl vs 9.7 [7.6-13.9] mg/dl, p<0.01). Logistic regression analysis showed that EPA use was an independent factor related to ventricular arrhythmia until 1 month, with an odds ratio of 0.29 (95% confidence interval, 0.09 to 0.96, p=0.04).</AbstractText>Early EPA treatment after PCI in the acute stage of MI reduces the incidence of ventricular arrhythmias, and lowers CRP values.</AbstractText>Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
11,379 | Thyroid hormone replacement therapy attenuates atrial remodeling and reduces atrial fibrillation inducibility in a rat myocardial infarction-heart failure model. | Heart failure (HF) is associated with increased atrial fibrillation (AF) risk. Accumulating evidence suggests the presence of myocardial tissue hypothyroidism in HF, which may contribute to HF development. In a recent report we demonstrated that hypothyroidism, like hyperthyroidism, leads to increased AF inducibility. The present study was designed to investigate the effect of thyroid hormone (TH) replacement therapy on AF arrhythmogenesis in HF.</AbstractText>Myocardial infarction (MI) was produced in rats by means of coronary artery ligation. Rats with large MIs (>40%) were randomized into L-thyroxine (T4; n = 14) and placebo (n = 15) groups 2 weeks after MI. Rats received 3.3 mg T4 (in 60-day release form) or placebo pellets for 2 months. Compared with the placebo, T4 treatment improved cardiac function and decreased left ventricular internal diameters as well as left atrial diameter. T4 treatment attenuated atrial effective refractory period prolongation (45 ± 1.5 ms in placebo group vs 37 ± 1.6 ms in T4 group; P < .01) and reduced AF inducibility (AF/atrial flutter/tachycardia were inducible in 11/15 rats [73%] in the placebo- vs 4/14 rats [29%] in the T4-treated group; P < .05). Arrhythmia reduction was associated with decreased atrial fibrosis but was not associated with connexin 43 changes.</AbstractText>To our knowledge this is the first study demonstrating that TH replacement therapy in HF attenuates atrial remodeling and reduces AF inducibility after MI-HF. Clinical studies are needed to confirm such benefits in human patients.</AbstractText>Copyright © 2014 Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,380 | Seventy-two hours of mild hypothermia after cardiac arrest is associated with a lowered inflammatory response during rewarming in a prospective observational study. | Whole-body ischemia and reperfusion trigger a systemic inflammatory response. In this study, we analyzed the effect of temperature on the inflammatory response in patients treated with prolonged mild hypothermia after cardiac arrest.</AbstractText>Ten comatose patients with return of spontaneous circulation after pulseless electrical activity/asystole or prolonged ventricular fibrillation were treated with mild therapeutic hypothermia for 72 hours after admission to a tertiary care university hospital. At admission and at 12, 24, 36, 48, 72, 96 and 114 hours, the patients' temperature was measured and blood samples were taken from the arterial catheter. Proinflammatory interleukin 6 (IL-6) and anti-inflammatory (IL-10) cytokines and chemokines (IL-8 and monocyte chemotactic protein 1), intercellular adhesion molecule 1 and complement activation products (C1r-C1s-C1inhibitor, C4bc, C3bPBb, C3bc and terminal complement complex) were measured. Changes over time were analyzed with the repeated measures test for nonparametric data. Dunn's multiple comparisons test was used for comparison of individual time points.</AbstractText>The median temperature at the start of the study was 34.3°C (33.4°C to 35.2°C) and was maintained between 32°C and 34°C for 72 hours. All patients were passively rewarmed after 72 hours, from (median (IQR)) 33.7°C (33.1°C to 33.9°C) at 72 hours to 38.0°C (37.5°C to 38.1°C) at 114 hours (P <0.001). In general, the cytokines and chemokines remained stable during hypothermia and decreased during rewarming, whereas complement activation was suppressed during the whole hypothermia period and increased modestly during rewarming.</AbstractText>Prolonged hypothermia may blunt the inflammatory response after rewarming in patients after cardiac arrest. Complement activation was low during the whole hypothermia period, indicating that complement activation is also highly temperature-sensitive in vivo. Because inflammation is a strong mediator of secondary brain injury, a blunted proinflammatory response after rewarming may be beneficial.</AbstractText> |
11,381 | Indications for intervention in asymptomatic children with chronic mitral regurgitation. | Based on outcome data, surgery is recommended for asymptomatic adults with chronic mitral regurgitation (MR) and systolic dysfunction, marked left ventricular (LV) dilation, pulmonary hypertension, atrial fibrillation, or high likelihood of successful repair; but indications for children are poorly defined. We sought to determine predictors of postoperative LV dysfunction in asymptomatic children with chronic MR. The surgical database was searched for all children who underwent mitral valve surgery for chronic MR (2000-2012). Exclusion criteria were preoperative symptoms, acute MR, cardiomyopathy, or other defects affecting LV size. Preoperative and latest follow-up clinical and echocardiographic data were obtained. LV dysfunction was defined as ejection fraction (EF) ≤55% or shortening fraction (SF) ≤28%. Associations between preoperative factors and late LV dysfunction were determined using univariate Poisson regression. For the 25 children who met criteria, preoperative median LV end systolic Z score (LVESZ) was 5.3, EF was 65%, and SF was 34%. At follow-up (median 3.9 years), nine patients (36%) had LV dysfunction. Lower preoperative SF (OR 0.6, p < 0.001) and higher LVESZ (OR 1.7, p < 0.01) were associated with late LV dysfunction. LVESZ ≥ 5 combined with SF ≤ 33% had a sensitivity of 89%, specificity of 88%, and negative predictive value of 93% for late LV dysfunction. Only 1/14 patients with preoperative SF > 33% had late LV dysfunction. For asymptomatic children with chronic MR, surgery should be considered before LVESZ exceeds five and SF falls below 33%. Patients with SF > 33% may be followed with serial echocardiographic measurements. |
11,382 | Neurologic causes of cardiac arrest and outcomes. | Sudden cardiac arrest as a complication of neurologic disorders is rare, occasionally acute neurologic events present with cardiac arrest as initial manifestation.</AbstractText>Our aim was to describe neurologic disorders as a cause of cardiac arrest in order to enable better recognition.</AbstractText>We retrospectively analyzed prospectively collected resuscitation data of all patients treated between 1991 and 2011 at the emergency department after cardiac arrest caused by a neurologic event, including diagnosis, therapy, and outcomes.</AbstractText>Over 20 years, 154 patients suffered cardiac arrest as a result of a neurologic event. Out-of-hospital cardiac arrest occurred in 126 (82%) patients, 78 (51%) were male, median age was 51 years (interquartile range 17 to 89 years). As initial electrocardiogram rhythm, pulseless electrical activity was found in 77 (50%) cases, asystole in 61 (40%), and ventricular fibrillation in 16 (10%) cases. The most common cause was subarachnoid hemorrhage in 74 (48%) patients, 33 (21%) patients had intracerebral hemorrhage, 23 (15%) had epileptic seizure, 11 (7%) had ischemic stroke, and 13 (8%) had other neurologic diseases. Return of spontaneous circulation was achieved in 139 (90%) patients. Of these, 22 (14%) were alive at follow-up after 6 months, 14 (9%) with favorable neurologic outcome, 8 of these with epileptic seizure, and most of them with history of epilepsy.</AbstractText>Subarachnoidal hemorrhage is the leading neurologic cause of cardiac arrest. Most of the patients with cardiac arrest caused by neurologic disorder have a very poor prognosis.</AbstractText>Copyright © 2014 Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,383 | Brugada syndrome: a review of the literature. | Brugada syndrome is an example of a channelopathy caused by an alteration in the transmembrane ion currents that together constitute the cardiac action potential. Approximately 20% of the cases of Brugada syndrome have been shown to be associated with mutations in the gene coding for the sodium ion channel in the cell membranes of the muscle cells of the heart. Patients with Brugada syndrome are prone to develop ventricular tachyarrhythmias that may lead to syncope, cardiac arrest or sudden cardiac death. Many clinical situations have been reported to unmask or exacerbate the electrocardiography (ECG) pattern of Brugada syndrome. Genetic testing for Brugada syndrome is clinically available. Here we report two cases of Brugada syndrome followed by a comprehensive review of the literature. |
11,384 | Left ventricular ejection fraction normalization in cardiac resynchronization therapy and risk of ventricular arrhythmias and clinical outcomes: results from the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT) trial. | Appropriate guideline criteria for use of implantable cardioverter-defibrillators (ICDs) do not take into account potential recovery of left ventricular ejection fraction (LVEF) in patients treated with CRT-defibrillator.</AbstractText>Patients randomized to CRT-defibrillator from the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT) trial who survived and had paired echocardiograms at enrollment and at 12 months (n=752) were included. Patients were evaluated by LVEF recovery in 3 groups (LVEF ≤35% [reference], 36%-50%, and >50%) on outcomes of ventricular tachyarrhythmias (VTAs), VTA ≥200 bpm, ICD shock, heart failure or death, and inappropriate ICD therapy by multivariable Cox models. A total of 7.3% achieved LVEF normalization (>50%). The average follow-up was 2.2±0.8 years. The risk of VTA was reduced in patients with LVEF >50% (hazard ratio [HR], 0.24; 95% confidence interval [CI], 0.07-0.82; P=0.023) and LVEF of 36% to 50% (HR, 0.44; 95% CI, 0.28-0.68; P<0.001). Among patients with LVEF >50%, only 1 patient had VTA ≥200 bpm (HR, 0.16; 95% CI, 0.02-1.51), none were shocked by the ICD, and 2 died of nonarrhythmic causes. The risk of HF or death was reduced with improvements in LVEF (LVEF >50%: HR, 0.29; 95% CI, 0.09-0.97; P=0.045; and LVEF of 36%-50%: HR, 0.44; 95% CI, 0.28-0.69; P<0.001). For inappropriate ICD therapy, no additional risk reduction for LVEF>50% was seen compared with an LVEF of 36% to 50%. A total of 6 factors were associated with LVEF normalization, and patients with all factors present (n=42) did not experience VTAs (positive predictive value, 100%).</AbstractText>Patients who achieve LVEF normalization (>50%) have very low absolute and relative risk of VTAs and a favorable clinical course within 2.2 years of follow-up. Risk of inappropriate ICD therapy is still present, and these patients could be considered for downgrade from CRT-defibrillator to CRT-pacemaker at the time of battery depletion if no VTAs have occurred.</AbstractText>http://www.clinicaltrials.gov. Unique identifier: NCT00180271.</AbstractText>© 2014 American Heart Association, Inc.</CopyrightInformation> |
11,385 | Challenges in the echocardiographic assessment of aortic stenosis. | Calcific aortic valve stenosis is common in the elderly. While history and examination can establish the diagnosis, determination of its severity typically requires echocardiography to define valve anatomy, measure stenosis severity and assess left ventricular response. The purpose of this review is to describe some of the commonly encountered challenges in the echocardiographic assessment of aortic stenosis. These include errors in the calculation of aortic valve area, assessment of aortic stenosis during atrial fibrillation, determining the presence of aortic stenosis in the setting of low transvalvular pressure gradients and discriminating other forms of obstruction to left ventricular ejection from aortic stenosis. Lastly, a review of how echocardiography is utilized to select patients for transcatheter aortic valve replacement is presented. |
11,386 | Influence of atrial fibrillation in trans-catheter aortic valve replacement. | In high-risk patients with severe aortic stenosis transcatheter aortic valve replacement (TAVR) procedures have been found to be beneficial. Up to now TAVR has been preferably performed on elderly patients, who cannot undergo conventional aortic valve replacement (AVR). Usually, due to their advanced age, these patients suffer from atrial fibrillation (AF) and are also more predisposed to present left ventricular dysfunction. Both conditions influence short and long-term prognosis in conventional AVR surgery. We do not really know how this translates in new procedures such as TAVR. The purpose of the present paper was to review how AF could affect TAVR procedures. |
11,387 | Early in-vivo hemodynamic comparison of supra-annular aortic bioprostheses: Trifecta versus Perimount Magna Ease. | The study aim was to compare early postoperative hemodynamic gradients after supra-annular implantation of the Trifecta and Perimount Magna Ease aortic bioprostheses.</AbstractText>Between January 2010 and December 2011, a total of 235 patients (105 males, 130 females; mean age at surgery 73.8 +/- 10.2 years) underwent supra-annular aortic valve replacement (AVR), with or without concomitant procedures. The patients were divided into 2 groups receiving either the Perimount Magna Ease (n = 117) or Trifecta (n = 118). Concomitant procedures were performed in 133 patients (56.6%), and 25 procedures (10.6%) were redos. Patients with postoperative severe left ventricular dysfunction and moderate to severe mitral regurgitation were excluded. Gradients were calculated pre-discharge using transthoracic echocardiography. Effective orifice area calculations were not performed. Data were collected retrospectively from hospital databases and analyzed using SPSS 17.</AbstractText>Both groups compared well for 14 variables. Group A had a higher number of redo operations and the patients were younger. Postoperative peak and mean gradients (in mmHg) for the Magna Ease group versus Trifecta group were: 19 mm valves, 33.5 +/- 16 versus 24.7 +/- 10 (p = 0.11) and 17.4 +/- 6.5 versus 12.7 +/- 4.4 (p = 0.05); 21 mm, 27.2 +/- 9.1 versus 21.8 +/- 7.2 (p = 0.001) and 13.8 +/- 4.7 versus 10.7 +/- 3.4 (p = 0.001); 23 mm, 25.6 +/- 7.8 versus 20.1 +/- 7.9 (p = 0.005) and 13 +/- 4 versus 10.1 +/- 4.3 (p = 0.002); 25 mm, 22.3 +/- 7.8 versus 15.6 +/- 5.1 (p = 0.01) and 12.8 +/- 4.1 versus 8 +/- 2.8 (p = 0.02). The overall mortality was 3.4%. The median hospital stay was nine days in both groups (p = 0.13). Mortality (p = 0.5), and incidences of perioperative stroke (p = 0.45), postoperative new-onset atrial fibrillation (p = 0.26) and permanent pacemaker implantation (p = 0.8) were similar in both groups.</AbstractText>Early postoperative gradients were significantly lower in patients receiving Trifecta valves, although the long-term clinical outcome and durability of the valve will require further evaluation.</AbstractText> |
11,388 | Mitral valve regurgitation after atrial septal defect repair in adults. | Mitral valve regurgitation (MR) is known to deteriorate following adult atrial septal defect (ASD) repair in the mid to long-term. The study aim was to identify the risk factors for this deterioration.</AbstractText>Between 1995 and 2011, a total of 93 consecutive patients (aged > or = 18 years) underwent ASD repair at the authors' institution. Patients who underwent concomitant procedures, other than tricuspid annuloplasty or maze procedure, were excluded; hence, 74 patients were enrolled in the study. MR was evaluated by transthoracic echocardiography shortly after surgery and subsequently on a regular basis in the outpatient clinic. Risk factors for the deterioration of MR were estimated using Cox proportional hazards regression.</AbstractText>The mean patient age at surgery was 48.0 +/- 17.1 years, and 20 patients (27%) had atrial fibrillation (AF) preoperatively. The mean follow up was 6.9 +/- 5.5 years. The degree of MR was not unchanged or not improved in 54 patients (73.0%) (group 1), but was increased by one grade in 12 patients (16.2%) (group 2), and by two or more grades in eight patients (10.8%) (group 3). At surgery, all patients in group 3 were aged > 50 years. In group 3, on echocardiography, the average end-diastolic left ventricular dimension was increased from 41.8 mm to 51.8 mm (p = 0.027), and enlargement of the mitral annulus was noted in seven patients. Four of the group 3 patients required reoperation for MR after ASD repair. The Cox proportional hazards model revealed preoperative AF (p = 0.045, hazard ratio (HR): 11.68, 95% confidence interval (95% CI): 1.05-129.48) and Qp/Qs > or = 2.8 (p = 0.015, HR: 9.19, 95% CI :1.53-55.04) to be independent risk factors of new-onset or aggravated MR (by two or more grades) after ASD repair.</AbstractText>An earlier repair of ASD would be preferable in terms of MR aggravated after ASD repair. For elderly patients with a preoperative high Qp/Qs and AF, mitral valve annuloplasty with ASD repair should considered.</AbstractText> |
11,389 | The use of external event monitoring (web-loop) in the elucidation of symptoms associated with arrhythmias in a general population. | To correlate arrhythmic symptoms with the presence of significant arrhythmias through the external event monitoring (web-loop).</AbstractText>Between January and December 2011, the web-loop was connected to 112 patients (46% of them were women, mean age 52±21 years old). Specific arrhythmic symptoms were defined as palpitations, pre-syncope and syncope observed during the monitoring. Supraventricular tachycardia, atrial flutter or fibrillation, ventricular tachycardia, pauses greater than 2 seconds or advanced atrioventricular block were classified as significant arrhythmia. The association between symptoms and significant arrhythmias were analyzed.</AbstractText>The web-loop recorded arrhythmic symptoms in 74 (66%) patients. Of these, in only 14 (19%) patients the association between symptoms and significant cardiac arrhythmia was detected. Moreover, significant arrhythmia was found in 11 (9.8%) asymptomatic patients. There was no association between presence of major symptoms and significant cardiac arrhythmia (OR=0.57, CI95%: 0.21-1.57; p=0.23).</AbstractText>We found no association between major symptoms and significant cardiac arrhythmia in patients submitted to event recorder monitoring. Event loop recorder was useful to elucidate cases of palpitations and syncope in symptomatic patients.</AbstractText> |
11,390 | Spontaneous coronary artery dissection: association with predisposing arteriopathies and precipitating stressors and cardiovascular outcomes. | Nonatherosclerotic spontaneous coronary artery dissection (NA-SCAD) is underdiagnosed and an important cause of myocardial infarction in young women. The frequency of predisposing and precipitating conditions and cardiovascular outcomes remains poorly described.</AbstractText>Patients with NA-SCAD prospectively evaluated (retrospectively or prospectively identified) at Vancouver General Hospital were included. Angiographic SCAD diagnosis was confirmed by 2 experienced interventional cardiologists and categorized as type 1 (multiple lumen), 2 (diffuse stenosis), or 3 (mimic atherosclerosis). Fibromuscular dysplasia screening of renal, iliac, and cerebrovascular arteries were performed with angiography or computed tomographic angiography/MR angiography. Baseline, predisposing and precipitating conditions, angiographic, revascularization, in-hospital, and long-term events were recorded. We prospectively evaluated 168 patients with NA-SCAD. Average age was 52.1±9.2 years, 92.3% were women (62.3% postmenopausal). All presented with myocardial infarction. ECG showed ST-segment elevation in 26.1%, and 3.6% had ventricular tachycardia/ventricular fibrillation arrest. Fibromuscular dysplasia was diagnosed in 72.0%. Precipitating emotional or physical stress was reported in 56.5%. Majority had type 2 angiographic SCAD (67.0%), only 29.1% had type 1, and 3.9% had type 3. The majority (134/168) were initially treated conservatively. Overall, 6 of 168 patients had coronary artery bypass surgery and 33 of 168 had percutaneous coronary intervention in-hospital. Of those treated conservatively (n=134), 3 required revascularization for SCAD extension, and all 79 who had repeat angiogram ≥26 days later had spontaneous healing. Two-year major adverse cardiac events were 16.9% (retrospectively identified group) and 10.4% (prospectively identified group). Recurrent SCAD occurred in 13.1%.</AbstractText>Majority of patients with NA-SCAD had fibromuscular dysplasia and type 2 angiographic SCAD. Conservative therapy was associated with spontaneous healing. NA-SCAD survivors are at risk for recurrent cardiovascular events, including recurrent SCAD.</AbstractText>© 2014 American Heart Association, Inc.</CopyrightInformation> |
11,391 | Subarachnoid haemorrhage imitating acute coronary syndrome as a cause of out-of-hospital cardiac arrest - case report. | Severe subarachnoid haemorrhage (SAH) is a common cause of cardiac arrest. The survival of patients with out-of-hospital cardiac arrest (OHCA) due to SAH is extremely poor. Electrocardiographic and echocardiographic changes associated with SAH may mimic changes caused by acute coronary syndromes (ACS) and thus lead to delayed treatment of the primary disease. Misdiagnosed SAH due to ACS mask can have an influence on patient outcomes.</AbstractText>A 47-year-old man presented with a history of out-of-hospital cardiac arrest due to asystole. He had a medical history of hypertension, smoking, and a diffuse, severe headache for one week. The ECG showed atrial fibrillation, 0,2 mV ST-segment elevation in leads aVR and V1-V3 and 0.2 mV ST-segment depression in leads I, II, aVL and V4-V6. Echocardiography revealed left ventricular function impairment (ejection fraction < 20%). The CK-MB activity was 98 U L⁻¹ and the troponin I concentration was 0.59 μg L⁻¹. ACS was suspected. Coronarography did not reveal any changes in the coronary arteries. An urgent CT of the head was arranged and showed an extensive SAH.</AbstractText>It appears that an urgent CT of the head is the most effective method for the early identification of SAH-induced OHCA, especially in patients with prodromal headache, no history of the symptoms of ACS and CA due to asystole/pulseless electrical activity (PEA). Out-of-hospital cardiac arrest (OHCA) predominantly develops due to acute coronary syndrome (ACS). Extra-cardiac causes, e.g., subarachnoid haemorrhage (SAH), are less common. The purpose of the present case report was to describe a patient with OHCA due to subarachnoid haemorrhage imitating acute coronary syndrome.</AbstractText> |
11,392 | [Emergency coronary artery bypass grafting for acute myocardial infarction presenting as cardio-pulmonary arrest during a marathon race; report of a case]. | We report a case of coronary artery bypass grafting for acute myocardial infarction which presented as cardio-pulmonary arrest during a marathon race. A 57-year-old man collapsed at the 18-km point in the Toyohashi half marathon. He was treated with an automated electrical defibrillator( AED) for ventricular fibrillation in an ambulance. Immediately after arriving at our emergency department, he was diagnosed with acute myocardial infarction by electrocardiography. Emergency coronary angiography revealed severe stenosis of the left anterior descending artery. Percutaneous coronary intervention was tried, but it was given up because calcification of the stenotic lesion was severe. He was then referred to our department for emergency coronary artery bypass grafting. Complete re-vascularization was accomplished and the patient has been doing well with no signs of angina. |
11,393 | [Usefulness of echocardiography for detecting prosthetic valve dysfunction; report of a case]. | A 78-year-old woman with a history of mitral valve stenosis underwent open mitral commissurotomy in 1976. In 1990, she underwent mitral valve replacement (Medtronic-Hall 29 mm), tricuspid annuloplasty(DeVega method), and pacemaker implantation for bradycardiac atrial fibrillation. However, in June 2012, she developed anemia of unknown cause. Prosthetic valve dysfunction was suspected, because intermittent changes in the left ventricular inflow was detected by echocardiography. Fluoroscopy actually confirmed the presence of prosthetic valve dysfunction. Therefore mitral valve re-replacement(ATS Medical, Inc. 29 mm) and tricuspid annuloplasty (Cosgrove ring 30 mm) were performed. Monitoring the changes in the left ventricular inflow is recommended when prosthetic valve dysfunction in a single leaflet is suspected. |
11,394 | Worsening thoracic impedance as a ventricular tachyarrhythmia risk. | The use of heart failure classification to identify patients with systolic dysfunction who are at risk for ventricular tachyarrhythmias (VAs), sudden cardiac death, and shocks from implantable cardioverter defibrillators (ICDs) is limited by its subjectivity. Measurement of thoracic impedance offers a more objective tool for assessing worsening of heart failure. We sought to look at the correlation between ventricular arrhythmia and heart failure as assessed objectively by thoracic impedance. We reviewed device interrogation data on thoracic impedance from ICD with Medtronic's OptiVol® feature (Medtronic Inc., Minneapolis, MN) at two medical centers. Data from the last two interrogations of the same device separated by at least 2 months were included. An OptiVol fluid index threshold of 60 represented early heart failure prior to appearance of symptoms. VAs included were ventricular fibrillation and/or ventricular tachycardia lasting more than 16 beats. Chi square distribution test was used in statistical data analysis. There were 24 VAs identified among the 322 interrogations reviewed (7.5%). Elevated OptiVol fluid index was seen in 71% (17/24), whereas normal OptiVol index was seen in the remaining 29% (7/24) of these interrogations with VA (P < .05). Our review shows that heart failure patients who have VA are approximately 2.5 times as likely to have worsening thoracic impedance as assessed objectively by the OptiVol fluid index. Careful monitoring of the OptiVol fluid index may identify a population at high risk of VA that merits more intense attention. |
11,395 | Low-level carotid baroreceptor stimulation suppresses ventricular arrhythmias during acute ischemia. | The autonomic imbalance during acute ischemia is involved in the occurrence of life-threatening arrhythmias.</AbstractText>To investigate the effect of autonomic nervous system (ANS) modulation by low-level carotid baroreceptor stimulation (LL-CBS) on ventricular ischemia arrhythmias.</AbstractText>Anesthetized dogs were received either sham treatment (SHAM group, n = 10) or LL-CBS treatment (LL-CBS group, n = 10). The voltage lowering the blood pressure was used as the threshold for setting LL-CBS at 80% below the threshold. Treatment started 1 hour before left anterior descending coronary (LAD) occlusion, and continued until the end of experience. Ventricular effective refractory periods (ERP), monophasic action potential duration at 90% (APD90), ventricular arrhythmias, indices of heart rate variability, left stellate ganglion nerve activity (LSGNA) and infarct sizes were measured and analyzed.</AbstractText>Ventricular ischemia resulted in an acute reduction of blood pressure, which was not significantly affected by LL-CBS. After 1 hour of LL-CBS, there was a progressive and significant increase in ERP, increase in APD90, and decrease in LSGNA vs the SHAM group (all P<0.05). LL-CBS apparently reduced premature ventricular contractions (PVC, 264±165 in the SHAM group vs 60±37 in the LL-CBS group; P<0.01) during LAD occlusion. Number of episodes of ventricular fibrillation (VF) was 8 in the Control group versus 3 in the LL-CBS group (80% versus 30%, P<0.05). LL-CBS obviously increased high frequency (HF) component (P<0.05) and decreased low frequency/high frequency ratio (P<0.05) compared with the SHAM group. Ischemic size was not affected by LL-CBS between the two groups.</AbstractText>LL-CBS reduced the occurrences of ventricular arrhythmias during acute ischemia without affecting blood pressure. The procedure was associated with changes of electrophysiological characteristics, nerve activity and heart rate variability. Therefore, LL-CBS may protect from ventricular arrhythmias during acute ischemic events by modulating ANS.</AbstractText> |
11,396 | Reduced risk for inappropriate implantable cardioverter-defibrillator shocks with dual-chamber therapy compared with single-chamber therapy: results of the randomized OPTION study. | The OPTION (Optimal Anti-Tachycardia Therapy in Implantable Cardioverter-Defibrillator Patients Without Pacing Indications) trial sought to compare long-term rates of inappropriate shocks, mortality, and morbidity between dual-chamber and single-chamber settings in implantable cardioverter-defibrillators (ICDs) patients.</AbstractText>The use of dual-chamber ICDs potentially allows better discrimination of supraventricular arrhythmias and thereby reduces inappropriate shocks. However, it may lead to detrimental ventricular pacing.</AbstractText>This prospective multicenter, single-blinded trial enrolled 462 patients with de novo primary or secondary prevention indications for ICD placement and with left ventricular ejection fractions ≤40% despite optimal tolerated pharmacotherapy. All patients received atrial leads and dual-chamber defibrillators that were randomized to be programmed either with dual-chamber or single-chamber settings. In the dual-chamber setting arm, the PARAD+ algorithm, which differentiates supraventricular from ventricular arrhythmias, and SafeR mode, to minimize ventricular pacing, were activated. In the single-chamber setting arm, the acceleration, stability, and long cycle search discrimination criteria were activated, and pacing was set to VVI 40 beats/min. Ventricular tachycardia detection was required at rates between 170 and 200 beats/min, and ventricular fibrillation detection was activated above 200 beats/min.</AbstractText>During a follow-up period of 27 months, the time to the first inappropriate shock was significantly longer in the dual-chamber setting arm (p = 0.012, log-rank test), and 4.3% of patients in the dual-chamber setting group compared with 10.3% in the single-chamber setting group experienced inappropriate shocks (p = 0.015). Rates of all-cause death or cardiovascular hospitalization were 20% for the dual-chamber setting group and 22.4% for the single-chamber setting group and satisfied the pre-defined margin for equivalence (p < 0.001).</AbstractText>Therapy with dual-chamber settings for ICD discrimination combined with algorithms for minimizing ventricular pacing was associated with reduced risk for inappropriate shock compared with single-chamber settings, without increases in mortality and morbidity. (Optimal Anti-Tachycardia Therapy in Implantable Cardioverter-Defibrillator [ICD] Patients Without Pacing Indications [OPTION]; NCT00729703).</AbstractText>Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
11,397 | Anaesthetic Postconditioning at the Initiation of CPR Improves Myocardial and Mitochondrial Function in a Pig Model of Prolonged Untreated Ventricular Fibrillation. | Anaesthetic postconditioning (APoC) attenuates myocardial injury following coronary ischaemia/reperfusion. We hypothesised that APoC at the initiation of cardiopulmonary resuscitation (CPR) will improve post resuscitation myocardial function along with improved mitochondrial function in a pig model of prolonged untreated ventricular fibrillation.</AbstractText>In 32 pigs isoflurane anaesthesia was discontinued prior to induction of ventricular fibrillation that was left untreated for 15 min. At the initiation of CPR, 15 animals were randomised to controls (CON), and 17 to APoC with 2 vol% sevoflurane during the first 3 min CPR. Pigs were defibrillated after 4 min of CPR. After return of spontaneous circulation (ROSC), isoflurane was restarted at 0.8-1.5 vol% in both groups. Systolic and diastolic blood pressures were measured continuously. Of the animals that achieved ROSC, eight CON and eight APoC animals were randomised to have their left ventricular ejection fraction (LVEF%) assessed by echocardiography at 4h. Seven CON and nine APoC were randomised to euthanasia 15 min after ROSC to isolate mitochondria from the left ventricle for bioenergetic studies.</AbstractText>ROSC was achieved in 10/15 CON and 15/17 APoC animals. APoC improved haemodynamics during CPR and post-CPR LVEF%. Mitochondrial ATP synthesis, coupling of oxidative phosphorylation and calcium retention capacity were improved in cardiac mitochondria isolated after APoC.</AbstractText>In a porcine model of prolonged untreated cardiac arrest, APoC with inhaled sevoflurane at the initiation of CPR, is associated with preserved mitochondrial function and improved post resuscitation myocardial dysfunction. Approved by the Institutional Animal Care Committee of the Minneapolis Medical Research Foundation of Hennepin County Medical Center (protocol number 11-05).</AbstractText>Published by Elsevier Ireland Ltd.</CopyrightInformation> |
11,398 | Role of cardiac multidetector computed tomography in the exclusion of ischemic etiology in heart failure patients. | Differentiation of ischemic from non-ischemic etiology in heart failure (HF) patients has both therapeutic and prognostic implications. One possible approach to this differentiation is direct visualization of the coronary tree. Multidetector computed tomography (MDCT) has emerged as an alternative to invasive coronary angiography (ICA), but its performance and additional clinical value are still not well validated in patients with left ventricular (LV) dysfunction. We aimed to assess the value of coronary MDCT angiography (CTA) in the exclusion of ischemic etiology in HF patients and to determine whether the Agatston calcium score could be used as a gatekeeper for CTA in this context.</AbstractText>We retrospectively selected symptomatic HF patients with LV ejection fraction (LVEF) <50%, as assessed by echocardiography, referred for CTA between April 2006 and May 2013. Patients with previously known CAD or valvular disease were excluded. The performance of MDCT in the detection of coronary artery disease (CAD) and/or exclusion of an ischemic etiology for HF was studied. Obstructive CAD was defined as the presence of ≥50% luminal stenosis in at least one epicardial coronary artery as assessed by CTA and was assumed in patients with an Agatston coronary artery calcium (CAC) score >400. In patients referred for ICA, an ischemic etiology was assumed in the presence of ≥75% stenosis in two or more epicardial vessels or ≥75% stenosis in the left main or proximal left anterior descending artery.</AbstractText>During this period 100 patients (mean age 57.3±10.5 years, 64% men) with HF and systolic dysfunction were referred for MDCT to exclude CAD. Median effective radiation dose was 4.8 mSv (interquartile range 5.8 mSv). Mean LVEF was 35±7.7% (range 20-48%) and median CAC score was 13 (interquartile range 212). Seven patients were in atrial fibrillation. Almost half of the patients (40%) had no CAC and none of these had significant stenosis on CTA. In an additional group of 33 patients CTA was able to confidently exclude obstructive CAD. Twenty-seven patients were classified as positive for CAD (16 due to CAC >400 and 11 with ≥50% stenosis) and were associated with lower LVEF (p=0.004). Of these, 21 patients subsequently underwent ICA: obstructive CAD was confirmed in nine and only six had criteria for ischemic cardiomyopathy.</AbstractText>In our HF population, MDCT was able to exclude an ischemic etiology in 73% of cases in a single test. According to our results the Agatston calcium score may serve as a gatekeeper for CTA in patients with HF, with a calcium score of zero confidently excluding an ischemic etiology.</AbstractText>Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.</CopyrightInformation> |
11,399 | Comparison of the rhythm control treatment strategy versus the rate control strategy in patients with permanent or long-standing persistent atrial fibrillation and heart failure treated with cardiac resynchronization therapy - a pilot study of Cardiac Resynchronization in Atrial Fibrillation Trial (Pilot-CRAfT): study protocol for a randomized controlled trial. | The only subgroups of patients with heart failure and atrial fibrillation in which the efficacy of cardiac resynchronization therapy has been scientifically proven are patients with indications for right ventricular pacing and patients after atrioventricular junction ablation. However it is unlikely that atrioventricular junction ablation would be a standard procedure in the majority of the heart failure patients with cardiac resynchronization therapy and concomitant atrial fibrillation due to the irreversible character of the procedure and a spontaneous sinus rhythm resumption that occurs in about 10% of these patients.</AbstractText><AbstractText Label="METHODS/DESIGN" NlmCategory="METHODS">Pilot-CRAfT is the first randomized controlled trial evaluating the efficacy of a rhythm control strategy in atrial fibrillation patients with cardiac resynchronization therapy devices. The aim of this prospective, single center randomized controlled pilot study is to answer the question whether the patients with cardiac resynchronization therapy and permanent atrial fibrillation would benefit from a strategy to restore and maintain sinus rhythm (that is 'rhythm control' strategy) in comparison to rate control strategy. The study population consists of 60 patients with heart failure and concomitant long-standing persistent or permanent atrial fibrillation who underwent a cardiac resynchronization therapy device implantation at least 3 months before qualification. Study participants are randomly assigned to the rhythm control strategy (including electrical cardioversion and pharmacotherapy) or to the rate control group whose goal is to control ventricular rate. The follow-up time is 12 months. The primary endpoint is the ratio of effectively captured biventricular beats. The secondary endpoints include peak oxygen consumption, six-minute walk test distance, heart failure symptom escalation, reverse remodelling of the heart on echo and quality of life.</AbstractText>NCT01850277 registered on 22 April 2013 (ClinicalTrials.gov).</AbstractText> |
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