Risk For Sustained Ventricular Tachycardia Research Articles

Comparison of four electrocardiographic criteria for the detection of cardiac abnormalities in Singapore athletes.

Sudden cardiac death in athletes is a rare occurrence, the most common cause being hypertrophic cardiomyopathy, which increases the risk of sustained ventricular tachycardia or ventricular fibrillation. Most of these young athletes are asymptomatic prior to the cardiac arrest. Several electrocardiogram criteria such as the European Society of Cardiology group 2 Criteria changes, Seattle Criteria, Refined Criteria, and most recently the 2017 International Criteria, have sought to improve the accuracy of identifying these at-risk athletes during pre-participation screening while minimising unnecessary investigations for the majority of athletes at low risk.We aimed to compare the above four criteria in our Singapore athlete population to identify which criterion performed the best in detecting cardiac abnormalities on echocardiography. Out of 1,515 athletes included in Changi General Hospital, Singapore registry between June 2007 and June 2014, the electrocardiograms of 270 athletes with further cardiac investigations were analysed. We compared the above four electrocardiographic criteria to evaluate which performed best for detecting cardiac abnormalities on echocardiography in our Southeast Asian athlete population. The European Society of Cardiology, Seattle, Refined and 2017 International Criteria had a sensitivity of 20%, 0%, 20% and 5%, respectively; a specificity of 64%, 93%, 84% and 97%, respectively; a positive predictive value of 4%, 0%, 9% and 11%, respectively; and a negative predictive value of 91%, 92%, 93% and 93%, respectively for detecting abnormalities on echocardiography. The latest 2017 International Criteria performed the best as it had the highest specificity and positive predictive value, joint highest negative predictive value, and lowest false positive rate.

Efficacy of catheter ablation for premature ventricular contractions in arrhythmogenic right ventricular cardiomyopathy.

Premature ventricular contractions (PVCs) may be found in any stage of arrhythmogenic right ventricular cardiomyopathy (ARVC) and have been associated with the risk of sustained ventricular tachycardia (VT). To investigate the role of PVC ablation in ARVC patients. We studied consecutive ARVC patients who underwent PVC ablation due to symptomatic high PVC burden. Mean daily PVC burden and antiarrhythmic drug (AAD) use were assessed before and after the procedure. Complete long-term success was defined as more than 80% reduction in PVC burden off of membrane-active AADs. Eight patients (37 ± 15 years; 4 males) underwent PVC ablation. The mean daily PVC burden before ablation ranged from 5.4% to 24.8%. A total of 7 (87.5%) patients underwent epicardial ablation. Complete acute elimination of PVCs was achieved in 4 (50%) patients (no complications). The mean daily PVC burden variation ranged from an 87% reduction to a 26% increase after the procedure. Over a median follow-up of 345 days (range: 182-3004 days), only one (12.5%) patient presented complete long-term success, and 6 (75%) patients either maintained or increased the need for Class I or Class III AADs. A total of 2 (25%) patients experienced sustained VT for the first time following the ablation procedure, requiring repeat ablation. No death or heart transplantation occurred. PVC ablation was not associated with a consistent reduction of the PVC burden in ARVC patients with symptomatic, frequent PVCs. PVC ablation may be reserved for highly symptomatic patients who failed AADs. Additional investigation is required to improve the efficacy of PVC ablation in ARVC patients.

Clinical characteristics of patients with sustained ventricular arrhythmias after sacubitril/valsartan initiation.

Our aim was to describe the clinical profile of patients presenting sustained ventricular arrhythmias after sacubitril/valsartan (SV) initiation. All cases of sustained ventricular arrhythmias in patients receiving SV were consecutively recorded in two centers. Nineteen patients had sustained ventricular arrhythmias after SV. All were men and were previously receiving angiotensin-converting enzyme inhibitors, or angiotensin II receptor blockers before SV initiation. Fifteen patients (78.9%) had electrical stability in the previous 6months. Nine patients (47.4%) initiated SV at the lowest available dose (24/26mg). Globally, in all but five patients alive at discharge, SV was discontinued after the event. Six patients presented new arrhythmic events after discontinuation of SV. Two deaths and three heart transplants occurred (one due to heart failure and the other two due to persistent ventricular arrhythmias). All patients had a high arrhythmic risk, and 17 (89.5%) had an implanted cardioverter defibrillator. No specific triggers for the arrhythmic event were found. Male sex and previous episodes of ventricular arrhythmias could be associated with an increased risk of sustained ventricular tachycardia after SV initiation. Discontinuation of the drug might be an additional approach to enable a better control of ventricular arrhythmias in some patients.

P797In which non-ischemic cardiomyopathies can the VCG identify those at risk for sustained ventricular tachycardia?

P797In which non-ischemic cardiomyopathies can the VCG identify those at risk for sustained ventricular tachycardia?

0261 : Prognostic value of the “infarct-like” pattern and cardiovascular magnetic resonance parameters for long-term outcome after an acute myocarditis

To assess the prognostic value of the clinically infarct-like pattern and cardiac magnetic resonance (CMR) parameters on long-term outcome after acute myocarditis. Between 2006 and 2015, 112 consecutive patients with CMRbased diagnosis of acute myocarditis according to the Louise-Lake criteria were identified in our institution. Of them, 88 were available for clinical follow-up and represent our studied population. Patients were divided into Infarct-like, (n=48) (association of acute chest pain, raised Troponin and STElevation) and non-infarct-like, (n=40) with any other presentation. The composite primary endpoint of Major CardioVascular Events included: all-cause mortality, cardiac mortality, recurrence of myocarditis, heart failure or sustained ventricular tachycardia. During follow-up, 21 patients (24%) experienced MACE and the infarct-like patients were significantly more at risk for MACE than group B patients (HR 2.4, 95% CI [1.01 – 5.80] p=0.04). Patients of the Group A exhibited in particular a higher risk of sustained ventricular tachycardia and recurrence of myocarditis as compared with group B patients (p=0.03). Infarct-like patients had lower CMR-derived left (p=0.03) and right (p=0.001) ventricular ejection fractions, and exhibited larger areas of late Gadolinium enhancement (LGE) (p=0.001) as compared with group B patients. In multivariate analysis, both initial NYHA functional class>II and LGE mass were independent predictors for long-term MACE occurrence after acute myocarditis (HR 5.8 and 1.07 per g respectively, p=0.007). Moreover, a threshold of LGE mass>17g provided a high discrimination for MACE occurrence (AUC of 0.81). The infarct-like pattern of acute myocarditis is associated with MACE, especially sustained ventricular tachycardia and recurrence of myocarditis. The author hereby declares no conflict of interest

Prognostic value of the infarct- and non-infarct like patterns and cardiovascular magnetic resonance parameters on long-term outcome of patients after acute myocarditis

BackgroundPrognostic value of the infarct- and non-infarct like patterns and cardiac magnetic resonance (CMR) parameters on long-term outcome of patients after acute myocarditis is not well known. MethodsBetween 2006 and 2015, 112 consecutive patients with CMR-based diagnosis of acute myocarditis were identified in our institution. Of them, 88 were available for clinical follow-up and represented our studied population. Patients were divided into infarct-like group (n=48) (association of acute chest pain, elevated Troponin levels and ST-elevation) and non-infarct-like group (n=40) with any other presentation. The composite primary endpoint of major cardiovascular events (MACE) included: all-cause mortality, cardiac mortality, recurrence of myocarditis, heart failure, and sustained ventricular tachycardia. ResultsDuring follow-up, 21 patients (24%) experienced MACE and infarct-like patients were significantly more at risk for MACE than non-infarct-like patients (HR 2.4, 95% CI [1.01–5.80] p=0.04). Infarct-like patients exhibited in particular a higher risk of sustained ventricular tachycardia and recurrence of myocarditis (p=0.03). They had lower CMR-derived left (p=0.03) and right (p=0.001) ventricular ejection fractions, and exhibited larger areas of late gadolinium enhancement (LGE) (p=0.001).In multivariate analysis, both initial NYHA functional class >II and LGE mass were independent predictors for long-term MACE occurrence (HR 5.8 and 1.07 per gram respectively, p=0.007). Moreover, a threshold of LGE mass >17g provided a high discrimination for MACE occurrence (AUC of 0.81). ConclusionsThe infarct-like pattern of acute myocarditis is associated with MACE occurrence. Initial NYHA functional class >II and LGE are independent predictive factors of MACE during long-term follow-up after acute myocarditis.

Incidence of Sustained Ventricular Tachycardia in Patients with Prolonged QTc After the Administration of Azithromycin: A Retrospective Study.

BackgroundAzithromycin has been associated with abnormalities of cardiac repolarization and development of torsades de pointes. Observational data suggest that the risk of death from cardiovascular causes is increased in patients taking azithromycin. Little is known regarding the risk of ventricular arrhythmia in patients with prolongation of the corrected QT interval who receive azithromycin.ObjectiveThe purpose of this study was to determine the incidence of sustained ventricular tachycardia in patients with prolonged corrected QT (QTc) who subsequently received azithromycin.MethodsWe performed a retrospective cohort analysis of the incidence of sustained ventricular tachycardia in patients with prolonged QTc (greater than 450 ms) who successively received intravenous (IV) and/or oral azithromycin. Patients hospitalized in a tertiary care teaching hospital between November 2009 and June 2012 were included in the study. The primary outcome was sustained ventricular tachycardia documented in patients on telemetry.ResultsOf the 103 patients enrolled in the study, only one patient experienced the primary outcome (0.97 %). The event occurred 1 day after the administration of a single dose of 500 mg IV azithromycin.ConclusionThe risk of sustained ventricular tachycardia was 0.97 % in our cohort of patients with prolonged QTc who subsequently received azithromycin. Given the small size of this study, additional research is needed to determine the true incidence of arrhythmia in the population.

Long-Term Prognostic Role oftheDiagnostic Criteria for Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia.

The aim of this study was to evaluate the long-term prognostic role of the 2010 task force criteria (TFC)-based scoring in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). Categories of the 2010 TFC include the risk factors for cardiovascular mortality and sudden cardiac death in patients with ARVC/D. Ninety patients with ARVC/D who met the definitive diagnosis of the 2010 TFC were retrospectively studied. ARVC/D risk score was calculated as the sum of major (2 points) and minor (1 point) criteria in all 6 subdivided categories of the TFC and was divided into tertile groups of scores; group A (4 to 6 points), group B (7 to 9 points), and group C (10to 12 points). The primary endpoints were major adverse cardiovascular events: cardiovascular death, heart failure hospitalization, and sustained ventricular tachycardia or ventricular fibrillation. During the follow-up period of 10.2 ± 7.1 years, 19 patients died because of cardiovascular causes, 28 patients were admitted because of worsened heart failure, and 47 patients experienced sustained ventricular tachycardia or ventricular fibrillation. Patients in groups B and C were at increased risk for major adverse cardiovascular events compared with those in group A (hazard ratio [HR]: 4.80; 95% confidence interval [CI]: 1.87 to 12.33; p= 0.001; and HR:6.15; 95% CI: 2.20 to 17.21; p= 0.001, respectively). Patients in groups B and C were at increased risk for sustained ventricular tachycardia or ventricular fibrillation compared with those in group A (HR: 6.64; 95% CI: 2.00 to 22.03; p=0.002; and HR: 9.18; 95% CI: 2.60 to 32.40; p= 0.001, respectively). Our study suggests that risk scoring based on the 2010 TFC is useful to predict major adverse cardiovascular events in patients with ARVC/D.

Rare Incidence of Ventricular Tachycardia and Torsades de Pointes in Hospitalized Patients With Prolonged QT Who Later Received Levofloxacin: A Retrospective Study

ObjectiveTo determine the incidence of ventricular tachycardia and ventricular fibrillation in patients with prolonged corrected QT interval (QTc) who received levofloxacin through retrospective chart review at a tertiary care teaching hospital in the United States. Patients and MethodsWe selected 1004 consecutive hospitalized patients with prolonged QTc (>450 ms) between October 9, 2009 and June 12, 2012 at our institution. Levofloxacin was administered orally and/or intravenously and adjusted to renal function in the inpatient setting. The primary outcome measure was sustained ventricular tachycardia recorded electrocardiographically. ResultsWith a median time from the start of levofloxacin use to hospital discharge (or death) of 4 days (range, 1-94 days), only 2 patients (0.2%; 95% CI, 0.0%-0.7%) experienced the primary outcome of sustained ventricular tachycardia after the initiation of levofloxacin use. ConclusionIn this study, the short-term risk for sustained ventricular tachycardia in patients with a prolonged QTc who subsequently received levofloxacin was very rare. These results suggest that levofloxacin may be a safe option in patients with prolonged QTc; however, studies with longer follow-up are needed.

Magnetic resonance estimates of the extent and heterogeneity of scar tissue in ICD patients with ischemic cardiomyopathy predict ventricular arrhythmia.

The majority of patients receiving implantable cardioverter-defibrillator (ICD) implantation under current guidelines never develop sustained ventricular arrhythmia; therefore, better markers of risk for sustained ventricular tachycardia and/or ventricular fibrillation are needed. The purpose of this study was to identify cardiac magnetic resonance arrhythmic risk predictors of ischemic cardiomyopathy before ICD implantation. Forty-three subjects (mean age, 64.5 ± 11.9 years) with previous myocardial infarction who were referred for ICD implantation were evaluated by cardiac magnetic resonance imaging (MRI). The MRI protocol included left ventricular functional parameter assessment using steady-state free precession and late gadolinium enhancement MRI using inversion recovery fast gradient echo. Left ventricular functional parameters were measured using cardiac magnetic resonance software. Subjects were followed up for 6-46 months, and the events of appropriate ICD treatments (shocks and antitachycardia pacing) were recorded. Twenty-eight patients experienced 46 spontaneous episodes during a median follow-up duration of 30 months. The total myocardial infarct (MI) size (18.05 ± 11.44 g vs 38.83 ± 19.87 g; P = .0006), MI core (11.63 ± 7.14 g vs 24.12 ± 12.73 g; P = .0002), and infarct gray zone (6.43 ± 4.64 g vs 14.71 ± 7.65 g; P = .0004) were significantly larger in subjects who received appropriate ICD therapy than in those who did not experience an episode of ventricular tachycardia and/or ventricular fibrillation. Multivariate regression analyses for the infarct gray zone and MI core adjusted for New York Heart Association class, diabetes, and etiology (primary or secondary prevention) revealed that the gray zone and MI core were predictors of appropriate ICD therapies (P = .0018 and P = .007, respectively). The extent of MI scar may predict which patients would benefit most from ICD implantation.

Abstract 9375: Sum Absolute QRST Integral Predicts Low Risk of Ventricular Tachyarrhythmias and Sudden Cardiac Death In MADIT II Study

Introduction. The need to extend risk stratification beyond use of ejection fraction is well recognized. New ECG risk marker, sum absolute QRST integral (SAI QRST) was recently proposed and was shown to be associated with low risk of sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) in patients with structural heart disease and primary prevention implantable cardioverter-defibrillators (ICDs). The objective of this study was to validate predictive value of SAI QRST in analysis of landmark ICD trial MADIT II. Methods. Baseline orthogonal ECGs were recorded at rest during sinus rhythm in 750 MADIT II study participants and analyzed by customized Matlab software. Absolute QRST integral was measured as the arithmetic sum of areas under the QRST curve, averaged during a 5-minute epoch. Then the sum magnitude of three orthogonal leads absolute QRST integral (SAI QRST) was calculated. Primary end-point for analysis was sustained VT/VF with appropriate ICD therapies (shock or antitachycardia pacing), or sudden cardiac death. Results. During 3.5 years of follow-up, 143 patients experienced sustained VT/VF with appropriate ICD therapies, or died suddenly. In univariate analysis lowest quartile of SAI QRST (< 116 mV*ms) was associated with decreased risk of sustained VT/VF with appropriate ICD therapies or sudden cardiac death (Figure 1). In multivariate analysis after adjustment for blood urea nitrogen and New York Heart Association functional class, low quartile SAI QRST was associated with decreased risk of VT/VF or sudden cardiac death as compared to three higher SAI QRST quartiles (Hazard Ratio 0.64 ; 95% CI 0.42 - 0.99 ; p=0.045). Conclusion . In post-myocardial infarction patients with depressed ejection fraction the lowest quartile of SAI QRST is associated with lower risk of sustained ventricular tachyarrhythmias and sudden cardiac death than it is observed in patients with higher SAI QRST values. Further study of SAI QRST is warranted.

Wavelet Analysis of High-Resolution Signal-Averaged Electrocardiograms in Postinfarction Patients with Bundle Branch Block

Time-domain analysis of the signal-averaged electrocardiogram (SAECG) can accurately predict risk of sustained ventricular tachycardia (VT) in patients with previous myocardial infarction (MI). Unfortunately, these patients often have bundle branch block (BBB) that obscures late potentials. We hypothesized that wavelet analysis might help predict VT risk in patients with BBB. We identified subjects with coronary disease and BBB who had undergone SAECG and programmed ventricular stimulation (PVS). We applied a modulated Gaussian wavelet to transform the ECG signal and looked for singularities in the wavelet coefficients. SAECG and PVS were obtained in 32 patients. Half had inducible sustained monomorphic VT by PVS and half had no inducible VT. There were no significant clinical differences between the groups. Comparing the number of singularities, we found no significant difference between the groups. Compared to previous work in patients without BBB, our patients with BBB had on average four times more singula- rities using an identical analysis technique. In the presence of BBB, abnormal myocardial activation patterns can generate ECG waveforms with time–frequency characteristics similar to those of cardiac late potentials. Wavelet-based methodologies may have limited ability to distinguish late potentials from the disordered ventricular activation occurring with BBB alone.

Recovery time dispersion measured from 87-lead body surface potential mapping as a predictor of sustained ventricular tachycardia in patients with idiopathic dilated cardiomyopathy.

The clinical usefulness of QT dispersion in 12-lead ECG has been controversial in identifying subjects at risk for sustained ventricular tachycardia (VT) in patients with idiopathic dilated cardiomyopathy (DCM). We hypothesized that increasing the spatial resolution of the ECG improves the accuracy of risk stratification. The purpose of this study was to test the ability of recovery time dispersion measured from 87-lead body surface potential mapping (BSPM) to identify patients at risk for sustained VT in idiopathic DCM. We obtained 87-lead BSPM and 12-lead ECG in 33 patients with idiopathic DCM (15 patients with a history of sustained VT [VT(+) group] and 18 patients without a history of sustained VT [VT(-) group]) and in 20 normal control subjects. We measured the corrected QT dispersion and corrected recovery time dispersion from 12-lead ECG (QTc-12 dispersion and RTc-12 dispersion, respectively) and 87-lead BSPM (QTc-87 dispersion and RTc-87 dispersion, respectively). Signal-averaged ECG also was recorded in 25 patients. Neither the QTc-12 nor QTc-87 dispersion discriminated between the VT(+) and VT(-) groups patients. The VT(+) group patients had a larger but insignificant RTc-12 dispersion than the VT(-) group patients. In contrast, the RTc-87 dispersion was significantly larger in the VT(+) group patients than in the VT(-) group patients (236 +/- 39 msec vs 184 +/- 28 msec, P < 0.001). Receiver operating curve analysis indicated that the RTc-87 dispersion was as good as late potentials in predicting susceptibility to sustained VT; its sensitivity, specificity, and negative predictive value were 73%, 76%, and 76%, respectively (cutoff value 200 msec). RTc-87 dispersion >200 msec combined with positive late potentials provide high sensitivity (92%) and high negative predictive value (88%) for sustained VT. The RTc-87 dispersion is a useful tool to identify subjects at risk for sustained VT in patients with idiopathic DCM.

Possible late potentials in 4 dogs with sustained ventricular tachycardia.

Signal-averaged electrocardiograms (SAEKGs) were performed on 4 dogs with sustained ventricular tachycardia. Quantitative and qualitative analyses of SAEKGs were consistent with the presence of late potentials. Two of the 4 dogs subsequently died suddenly, and ventricular tachycardia and ventricular fibrillation were observed in 1 dog. High-frequency QRS durations (75-90 milliseconds), duration of low amplitude (less than 40 microV) signals during the terminal QRS complex (LAS40) (28-40 milliseconds), root mean square voltages of the terminal 40 milliseconds of the QRS complex (RMS40) (124-6.5 microV), and root mean square voltages of the terminal 30 milliseconds of the QRS complex (RMS30) (13-2.1 microV) differed from results obtained in 68 of 70 control dogs. Echocardiographic data suggested dilated cardiomyopathy in 2 dogs and the cause of the arrhythmia in 2 dogs was not determined. The SAEKG may be a useful adjunct in identifying a subset of dogs with ventricular tachyarrhythmias that are at high risk for sustained ventricular tachycardia and sudden death. The sensitivity, specificity, and predictive accuracies of the technique remain to be determined.

Atrial flutter causes pseudo late potentials on signal-averaged electrocardiogram

Signal-averaged electrocardiography (SAECG) is a useful tool for determining which patients are at risk for sustained ventricular tachycardia. 1–3 In patients at risk for sustained ventricular tachycardia, SAECG often shows high-frequency and low-amplitude electrical activity at the terminal portion of the QRS complex. 4–6 This electrical activity is thought to be due to slow conduction in scarred or abnormal ventricular myocardial tissue and is usually not apparent on the standard 12-lead surface electrocardiogram. 7–10 During atrial flutter, flutter waves may occur before, during or after ventricular systole. Atrial flutter waves that occur during ventricular diastole frequently appear as “sawtooth” waves on the standard 12-lead electrocardiogram, particularly in the inferior limb or anterior chest leads. However, atrial flutter waves that occur during ventricular systole may be obscured by the QRS complex. To test the hypothesis that atrial flutter waves that coincide with the terminal portion of the QRS complex cause low-amplitude electrical activity and thus result in a pseudo late potential on the electrocardiogram, we performed SAECG in 9 patients during atrial flutter and normal sinus rhythm.

In patients with prior anterior myocardial infarction, early potentials are better than late potentials for identifying patients at risk for sustained ventricular tachycardia

In patients with prior anterior myocardial infarction, early potentials are better than late potentials for identifying patients at risk for sustained ventricular tachycardia