Objectives The aim of this study was to evaluate whether certain post-Maze left atrial (LA) contractile profiles may pose a risk for ischemic stroke. Background The mechanical contraction of the left ...atrium may be modified after the Maze procedure. Whether this imposes a risk for stroke, even in the presence of sinus rhythm and after removal of the LA appendage, is not known. Methods Clinical, surgery-related, and echocardiographic data from 150 patients who underwent radiofrequency and cryoablation Maze procedures without the use of atrial incisions between 2004 and 2009 and were in sustained sinus rhythm were collected and analyzed. The occurrence of stroke was evaluated by reviewing clinical records. All stroke events were adjudicated by a neurologist. Results At a mean follow-up time of 24.5 months, 15 patients (10%) had experienced ischemic strokes. Forty-seven patients (31%) had no evidence of LA mechanical contraction at 3 months after surgery (baseline assessment) and on follow-up echocardiography. Multivariate analysis showed that a lack of LA mechanical contraction at baseline was associated with a 5-fold increase in the risk for stroke (p = 0.02) during follow-up. Larger atria imposed a significant risk as well; LA volume index ≥33 ml/m2 was associated with a 3-fold risk increase (p = 0.03). These effects were maintained regardless of the lack of mechanical valve implantation and anticoagulation treatment. Conclusions Absence of LA contraction and LA volume index ≥33 ml/m2 result in a significant increase in the risk for thromboembolic stroke after the Maze procedure for patients in sinus rhythm.
Objectives The purpose of this study was to assess deformation dynamics and in vivo mechanical properties of the aortic annulus throughout the cardiac cycle. Background Understanding dynamic aspects ...of functional aortic valve anatomy is important for beating-heart transcatheter aortic valve implantation. Methods Thirty-five patients with aortic stenosis and 11 normal subjects underwent 256-slice computed tomography. The aortic annulus plane was reconstructed in 10% increments over the cardiac cycle. For each phase, minimum diameter, ellipticity index, cross-sectional area (CSA), and perimeter (Perim) were measured. In a subset of 10 patients, Young's elastic module was calculated from the stress-strain relationship of the annulus. Results In both subjects with normal and with calcified aortic valves, minimum diameter increased in systole (12.3 ± 7.3% and 9.8 ± 3.4%, respectively; p < 0.001), and ellipticity index decreased (12.7 ± 8.8% and 10.3 ± 2.7%, respectively; p < 0.001). The CSA increased by 11.2 ± 5.4% and 6.2 ± 4.8%, respectively (p < 0.001). Perim increase was negligible in patients with calcified valves (0.56 ± 0.85%; p < 0.001) and small even in normal subjects (2.2 ± 2.2%; p = 0.01). Accordingly, relative percentage differences between maximum and minimum values were significantly smallest for Perim compared with all other parameters. Young's modulus was calculated as 22.6 ± 9.2 MPa in patients and 13.8 ± 6.4 MPa in normal subjects. Conclusions The aortic annulus, generally elliptic, assumes a more round shape in systole, thus increasing CSA without substantial change in perimeter. Perimeter changes are negligible in patients with calcified valves, because tissue properties allow very little expansion. Aortic annulus perimeter appears therefore ideally suited for accurate sizing in transcatheter aortic valve implantation.
There is controversy regarding type of bundle branch block (BBB) that is associated with increased mortality risk in patients with heart failure (HF). The present study was designed to explore the ...association between BBB pattern and long-term mortality in hospitalized patients with systolic HF. Risk of 4-year all-cause mortality was assessed in 1,888 hospitalized patients with systolic HF (left ventricular ejection function <50%) without a pacemaker in a prospective national survey. Cox proportional hazards regression modeling was used to compare mortality risk in patients with right BBB (RBBB; 10%), left BBB (LBBB; 14%), and no BBB (76%) on admission electrocardiogram. At 4 years of follow up, mortality rates were highest in patients with RBBB (69%), intermediate in those with LBBB (63%), and lowest in those without BBB (50%, p <0.001). Multivariate analysis demonstrated a significant 36% increased mortality risk in patients with RBBB versus no BBB (p = 0.002) but no significant difference in mortality risk for patients with LBBB versus no BBB (hazard ratio 1.04, p = 0.66). RBBB versus LBBB was associated with a 29% (p = 0.035) increased risk for 4-year mortality in the total population and with a 58% (p = 0.015) increased risk in patients with ejection fraction <30%. In conclusion, RBBB but not LBBB on admission electrocardiogram is associated with a significant increased long-term mortality risk in hospitalized patients with systolic HF. Deleterious effects of RBBB compared to LBBB appear to be more pronounced in patients with more advanced left ventricular dysfunction.
Objectives We aimed to evaluate the relationship between echocardiographic response to cardiac resynchronization therapy (CRT) and the risk of subsequent ventricular tachyarrhythmias (VTAs). ...Background Current data regarding the effect of CRT on the risk of VTA are limited and conflicting. Methods The risk of a first appropriate implantable cardioverter-defibrillator (ICD) therapy for VTA (including ventricular tachycardia, ventricular fibrillation, and ventricular flutter) was compared between high- and low-echocardiographic responders to CRT defibrillator (CRT-D) therapy (defined as ≥25% and <25% reductions, respectively, in left ventricular end-systolic volume LVESV at 1 year compared with baseline) and ICD-only patients enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial–Cardiac Resynchronization Therapy). Results The cumulative probability of a first VTA at 2 years after assessment of echocardiographic response was highest among low responders to CRT-D (28%), intermediate among ICD-only patients (21%), and lowest among high responders to CRT-D (12%), with p < 0.001 for the overall difference during follow-up. Multivariate analysis showed that high responders to CRT-D experienced a significant 55% reduction in the risk of VTA compared with ICD-only patients (p < 0.001), whereas the risk of VTA was not significantly different between low responders and ICD-only patients (hazard ratio HR: 1.26; p = 0.21). Consistently, assessment of response to CRT-D as a continuous measure showed that incremental 10% reductions in left ventricular end-systolic volume were associated with corresponding reductions in the risk of subsequent VTA (HR: 0.80; p < 0.001), VTA/death (HR: 0.79; p < 0.001), ventricular tachycardia (HR: 0.80; p < 0.001), and ventricular fibrillation/ventricular flutter (HR: 0.75; p = 0.044). Conclusions In patients with left ventricular dysfunction enrolled in the MADIT-CRT trial, reverse remodeling was associated with a significant reduction in the risk of subsequent life-threatening VTAs. (Multicenter Automatic Defibrillator Implantation Trial–Cardiac Resynchronization Therapy MADIT-CRT; NCT00180271 )
Objectives This study hypothesized that time-dependent statin therapy will reduce the risk of life-threatening ventricular tachyarrhythmias among patients with nonischemic cardiomyopathy (NICM) ...enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy). Background Prior studies suggested that statin therapy exerts antiarrhythmic properties among patients with coronary artery disease. However, data regarding the effect of statins on arrhythmic risk among patients with NICM are limited. Methods Multivariate Cox proportional hazards regression modeling was used to assess the effect of statin therapy, evaluated as a time-dependent covariate, on the risk of appropriate defibrillator therapy for fast ventricular tachycardia (VT) (defined as a rate faster than 180 beats/min)/ventricular fibrillation (VF) or death (primary endpoint) and appropriate defibrillator shocks (secondary endpoint) among 821 patients with NICM enrolled in the MADIT-CRT trial. Results Statin users (n = 499) were older and had a higher prevalence of diabetes and hypertension yet were less frequently smokers. Multivariate analysis showed that time-dependent statin therapy was independently associated with a significant 77% reduction in the risk of fast VT/VF or death (p < 0.001) and with a significant 46% reduction in the risk of appropriate implantable cardioverter defibrillator shocks (p = 0.01). Consistent with these findings, the cumulative probability of fast VT/VF or death at 4 years of follow-up was significantly lower among patients who were treated with statins (11%) as compared with study patients who were not treated with statins (19%; p = 0.006 for the overall difference during follow-up). Conclusions Statin use was associated with a significant reduction in the risk of life-threatening ventricular tachyarrhythmias among patients with NICM.
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal arrhythmia provoked by physical or emotional stress and mediated by spontaneous Ca(2+) release and delayed ...after-depolarizations. Beta-adrenergic blockers are the therapy of choice but fail to control arrhythmia in up to 50% of patients.
To optimize antiarrhythmic therapy in recessively inherited CPVT caused by calsequestrin (CASQ2) mutations.
Murine heart rhythm telemetry was obtained at rest, during treadmill exercise, and after injection of epinephrine. The protocol was repeated after injection of different antiarrhythmic drugs. Results were then validated in human patients.
Adult CASQ2 mutant mice had complex ventricular arrhythmia at rest and developed bidirectional and polymorphic ventricular tachycardia on exertion. Class I antiarrhythmic agents (procainamide, lidocaine, flecainide) were ineffective in controlling arrhythmia. Propranolol and sotalol attenuated arrhythmia at rest but failed to prevent VT during sympathetic stimulation. The calcium channel blocker verapamil showed a dose-dependent protection against CPVT. Verapamil was more effective than the dihydropyridine L-type Ca(2+) channel blocker nifedipine, and its activity was markedly enhanced when combined with propranolol. Human patients homozygous for CASQ2(D307H) mutation, remaining symptomatic despite chronic β-blocker therapy, underwent exercise testing according to the Bruce protocol with continuous electrocardiogram recording. Verapamil was combined with propranolol at maximum tolerated doses. Adding verapamil attenuated ventricular arrhythmia and prolonged exercise duration in five of 11 patients.
Verapamil is highly effective against catecholamine-induced arrhythmia in mice with CASQ2 mutations and may potentiate the antiarrhythmic activity of β-blockers in humans with CPVT2.
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disease for which electrophysiological studies (EPS) have shown to be of limited value.
This study presents a CPVT ...family in which marked postpacing repolarization abnormalities during EPS were the only consistent phenotypic manifestation of ryanodine receptor (RyR2) mutation carriers.
The study was prompted by the observation of transient marked QT prolongation preceding initiation of ventricular fibrillation during atrial fibrillation in a boy with a family history of sudden cardiac death (SCD). Family members underwent exercise and pharmacologic electrocardiographic testing with epinephrine, adenosine, and flecainide. Noninvasive clinical test results were normal in 10 patients evaluated, except for both epinephrine- and exercise-induced ventricular arrhythmias in 1. EPS included bursts of ventricular pacing and programmed ventricular extrastimulation reproducing short-long sequences. Genetic screening involved direct sequencing of genes involved in long QT syndrome as well as RyR2.
Six patients demonstrated a marked increase in QT interval only in the first beat after cessation of ventricular pacing and/or extrastimulation. All 6 patients were found to have a heterozygous missense mutation (M4109R) in RyR2. Two of them, presenting with aborted SCD, also had a second missense mutation (I406T- RyR2). Four family members without RyR2 mutations did not display prominent postpacing QT changes.
M4109R- RyR2 is associated with a high incidence of SCD. The contribution of I406T to the clinical phenotype is unclear. In contrast to exercise testing, marked postpacing repolarization changes in a single beat accurately predicted carriers of M4109R- RyR2 in this family.
Abstract Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a primary electrical myocardial disease characterized by exercise- and stress-related ventricular tachycardia manifested as ...syncope and sudden death. The disease has a heterogeneous genetic basis, with mutations in the cardiac Ryanodine Receptor channel (RyR2) gene accounting for an autosomal-dominant form (CPVT1) in approximately 50% and mutations in the cardiac calsequestrin gene (CASQ2) accounting for an autosomal-recessive form (CPVT2) in up to 2% of CPVT cases. Both RyR2 and calsequestrin are important participants in the cardiac cellular calcium homeostasis. We review the physiology of the cardiac calcium homeostasis, including the cardiac excitation contraction coupling and myocyte calcium cycling. The pathophysiology of cardiac arrhythmias related to myocyte calcium handling and the effects of different modulators are discussed. The putative derangements in myocyte calcium homeostasis responsible for CPVT, as well as the clinical manifestations and therapeutic options available, are described.
...it seems that ischemia and infarction of a specific segment rather than infarct size account for the increase in both VF and acute HF risk in patients presenting with STE in lead V4R. Nonright ...STEMI) Odds Ratio* 95% Confidence Interval p Value Primary VF, acute HF, or death 54%vs.18% 8.8 2.7-28.8 <0.001 Acute HF 39%vs.17% 3.6 1.1-12.4 0.038 Primary VF 21%vs.3% -- -- -- Table 1 Risk Associated With ST-Segment Elevation in the Right Precordial Leads by Multivariate Analysis HF = heart failure; STEMI = ST-segment elevation myocardial infarction; VF = ventricular fibrillation.
Triggers and Timing of Acute Coronary Syndromes Tofler, Geoffrey H., MD; Kopel, Eran, MD; Klempfner, Robert, MD ...
The American journal of cardiology,
05/2017, Letnik:
119, Številka:
10
Journal Article
Recenzirano
Abstract Prior studies have shown that an acute coronary syndrome (ACS) may be triggered by external activities, however their frequency, predictors and significance are uncertain. We evaluated data ...from The National Israel Survey of Acute Coronary Syndromes, which was conducted in 2004 (February-March) in all 25 coronary care units and cardiac wards in Israel. Demographic and clinical data were recorded for consecutive participants, including potential triggers and time of symptom onset of ACS. Among the 1849 patients who completed the trigger question, one quarter (25.9%) reported a possible trigger, comprising heavy physical exertion (15.2%), emotional stress (8.3%), anger (1.1%), heavy meal (1.3%) and sexual activity (0.5%). Predictors of a triggered ACS were age <65 years, prior angina, no prior ACE / AT2 inhibitors, impaired functional class, not having typical chest pain on admission, and a final diagnosis of unstable angina. The highest proportion of triggered ACS was between noon- 6pm. Physical exertion as a trigger was associated with reduced in-hospital mortality (0.4 versus 2.8%, p <0.05) and 1-year mortality. Emotional stress as a trigger did not influence in-hospital or 1-year mortality, however among those discharged from hospital, it was associated with increased 30-day rehospitalisation (27.6 versus 19.3%, p <0.05) and a trend towards increased mortality (4.1 versus 2.0%, p=0.10).
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