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Early ventricular tachycardia (VT) and ventricular fibrillation (VF) are associated with increased in-hospital mortality but do not influence the long-term prognosis in ST-elevation myocardial infarction (STEMI). Recent data advocate a differential approach to the type of arrhythmia and indicate long-term mortality hazard associated with monomorphic VT. We aimed to evaluate the prognostic value of early monomorphic VT compared to nonmonomorphic VT/VF in a nonselected cohort of STEMI patients. Consecutive STEMI patients admitted for primary percutaneous coronary intervention from 2007 to 2010 were included. Clinical characteristics were obtained from the Swedish national SWEDEHEART registry. The occurrence and type of early VT/VF were verified in medical records. All-cause mortality 8 years after STEMI was assessed using the Swedish Cause of Death Register. A total of 2,277 STEMI patients were included (age 66 ± 12 years, 70% male), among them 35 (1.5%) with early monomorphic VT and 115 (5.1%) with nonmonomorphic VT/VF. Patients with monomorphic VT had similar clinical characteristics compared to those with nonmonomorphic VT/VF. In total, 22 patients (63%) with monomorphic VT and 43 (37%) with nonmonomorphic VT/VF died by 8 years of follow-up (p = 0.011). Monomorphic VT was associated with a higher risk of all-cause mortality compared to nonmonomorphic VT/VF in univariate analysis (HR 2.03, 95% CI 1.21 to 3.39, p = 0.007) and after adjustment for age and history of myocardial infarction (MI) (HR 1.74, 95% CI 1.02 to 2.97, p = 0.041). Early monomorphic VT in STEMI is associated with a higher risk of all-cause mortality compared to nonmonomorphic VT/VF and deserves further studies to refine risk stratification strategies., Competing Interests: Disclosures The authors have no conflicts of interest to declare., (Copyright © 2021. Published by Elsevier Inc.)

Catheter ablation may reduce ventricular tachycardia (VT) burden in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients. However, little is known about factors predicting need for ablation. Therefore, we sought to investigate predictors and use of VT ablation and to evaluate the postprocedural outcome in ARVC patients. We studied 435 patients from the Nordic ARVC registry including 220 probands with definite ARVC according to the 2010 task force criteria and 215 mutation-carrying relatives identified through cascade screening. Patients were followed until first-time VT ablation, death, heart transplantation, or January 1st 2018. Additionally, patients undergoing VT ablation were further followed from the time of ablation for recurrent ventricular arrhythmias. The cumulative use of VT ablation was 4% (95% confidence interval [CI] 3% to 6%) and 11% (95% CI 8% to 15%) after 1 and 10 years. All procedures were performed in probands in whom cumulative use was 8% (95% CI 5% to 12%) and 20% (95% CI 15% to 26%). In adjusted analyses among probands, only young age predicted ablation. In patients undergoing ablation, risk of recurrent arrhythmias was 59% (95% CI 44% to 71%) and 74% (95% CI 59% to 84%) 1 and 5 years after the procedure. Despite high recurrence rates, the burden of ventricular arrhythmias was reduced after ablation (p = 0.0042). Young age, use of several antiarrhythmic drugs and inducibility to VT after ablation were associated with an unfavorable outcome. In conclusion, twenty percent of ARVC probands developed a clinical indication for VT ablation within 10 years whereas mutation-carrying relatives were without such need. Although the burden of ventricular arrhythmias decreased after ablation, risk of recurrence was substantial., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Implantable cardioverter-defibrillator (ICD) therapy remains a corner stone of sudden cardiac death (SCD) prevention in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). We aimed to assess predictors of appropriate ICD therapies in the Scandinavian cohort of ARVC patients who received ICD for primary prevention of SCD. Study group comprised of 79 definite ARVC patients by 2010 Task Force criteria (60% male, age at ICD implant 39 ± 14 years) who were enrolled in the Nordic ARVC Registry and received an ICD for primary SCD prevention. The primary end point of appropriate ICD shock or death from any cause was assessed and compared with 137 definite ARVC patients who received ICD for secondary SCD prevention (74% male, age at ICD implant 42 ± 15 years). In the study group, 38% were ≤35 years of age at baseline, 25% had nonsustained ventricular tachycardia, and 29% had syncope at baseline. Major repolarization abnormality (hazard ratio = 4.00, 95% confidence interval 1.30 to 12.30, p = 0.015) and age ≤35 years (hazard ratio = 4.21, 95% confidence interval 1.49 to 11.85, p = 0.001) independently predicted the primary end point. The outcome did not differ between the primary prevention patients with either of these risk factors and the secondary prevention cohort (2% to 4% annual event rate) whereas patients without risk factors did not have any appropriate ICD shocks during follow-up. In conclusion, young age at ARVC diagnosis and major repolarization abnormality independently predict ICD shocks or death in the primary prevention ICD recipients and associated with the event rate similar to the one observed in the secondary prevention cohort. Our data indicate the benefit of ICD for primary prevention in patients with any of these risk factors., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Cardiac resynchronization therapy (CRT) has proven prognostic benefits in patients with heart failure (HF) with left bundle branch block (LBBB) QRS morphology. Electrocardiographic left atrial (LA) abnormality has been proposed as a noninvasive marker of atrial remodeling. We aimed to assess the impact of electrocardiographic LA abnormality for prognosis in patients with HF treated with CRT. Baseline resting 12-lead electrocardiograms recorded from 941 patients enrolled in the CRT arm of the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy was processed automatically using Glasgow algorithm, which included automated assessment of P-wave terminal force in lead V 1 (PTF-V 1 ) as a marker of LA abnormality. A PTF-V 1 of ≥0.04 mm⋅s was considered abnormal. The primary end point was HF event and/or death. Total mortality and appropriate defibrillator therapies were the secondary end points. At baseline 550, patients treated with CRT with a defibrillator had LBBB QRS morphology and normal PTF-V 1 . Normal PTF-V 1 was associated with significant risk reduction for all assessed end points and for the primary end point comprised a hazard ratio of 0.55 (95% confidence interval 0.36 to 0.84) compared with patients with LBBB with abnormal PTF-V 1 (n = 120), and a hazard ratio of 0.42 (95% confidence interval 0.32 to 0.55) compared with patients with implanted defibrillator (n = 729). In CRT-treated patients with HF, electrocardiographic LA abnormality appears to be an electrocardiographic indicator of poor long-term outcome in patients with LBBB. In conclusion, our data suggest that PTF-V 1 bears additive prognostic information in the context of CRT, thus further strengthening the role of electrocardiographic diagnostics in risk stratification of patients with HF., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Cardiac resynchronization therapy (CRT) reduces mortality and morbidity in selected patients with heart failure (HF), but up to 1/3 of patients are nonresponders. Sum absolute QRST integral (SAI QRST) recently showed association with mechanical response on CRT. However, it is unknown whether SAI QRST is associated with all-cause mortality and HF hospitalizations in patients undergoing CRT. The study population included 496 patients undergoing CRT (mean age 69 ± 10 years, 84% men, 65% left bundle branch block [LBBB], left ventricular ejection fraction 23 ± 6%, 63% ischemic cardiomyopathy). Preimplant digital 12-lead electrocardiogram was transformed into orthogonal XYZ electrocardiogram. SAI QRST was measured as an arithmetic sum of areas under the QRST curve on XYZ leads and was dichotomized based on the median value (302 mV ms). All-cause mortality served as the primary end point. A composite of 2-year all-cause mortality, heart transplant, and HF hospitalization was a secondary end point. Cox regression models were adjusted for known predictors of CRT response. Patients with preimplant low mean SAI QRST had an increased risk of both the primary (hazard ratio [HR] 1.8, 95% CI 1.01 to 3.2) and secondary (HR 1.6, 95% CI 1.1 to 2.2) end points after multivariate adjustment. SAI QRST was associated with secondary outcome in subgroups of patients with LBBB (HR 2.1, 95% CI 1.5 to 3.0) and with non-LBBB (HR 1.7, 95% CI 1.0 to 2.6). In patients undergoing CRT, preimplant SAI QRST <302 mV ms was associated with an increased risk of all-cause mortality and HF hospitalization. After validation in another prospective cohort, SAI QRST may help to refine selection of CRT recipients., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Reduced heart rate variability (HRV) is associated with poor outcome in patients with heart failure (HF). However, the data on predictive value of RR variability during atrial fibrillation (AF) are limited. Therefore, the aim of this study was to evaluate the association between ventricular response characteristics and long-term clinical outcome in the population of ambulatory patients with mild-to-moderate HF and AF at baseline. The study included 155 patients (mean age 69 ± 10 years) with AF at 20-minute Holter electrocardiographic (ECG) recordings at enrollment. HRV analysis included SDNN, rMSSD, and pNN50, whereas irregularity indexes included 2 nonlinear parameters: approximate entropy (ApEn) and Shannon entropy. After median 41 months of follow-up, 54 patients died, including 21 HF related and 16 sudden deaths. Patients with ApEn ≤1.68 (lower tertile) had 40% mortality versus 12% in others (p <0.001) at 2 years of follow-up. Only nonlinear HRV parameters (irregularity but not variability indexes) identified patients at higher risk during follow-up. Decreased ApEn ≤1.68 was an independent predictor of total mortality (hazard ratio [HR] 2.81, 95% confidence interval [CI] 1.61 to 4.89, p <0.001), sudden cardiac death (HR 3.83, 95% CI 1.31 to 11.25, p = 0.014), and HF death (HR 3.45, 95% CI 1.42 to 8.38, p = 0.006) in a multivariate Cox analysis. In conclusion, in a post hoc analysis of Muerte Subita en Insufficiencia Cardiaca study AF cohort, reduced irregularity of RR intervals during AF, likely caused by autonomic dysfunction, was an independent predictor of all-cause mortality and sudden death and HF progression in patients with mild-to-moderate HF, whereas traditional HRV indexes did not predict outcome., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Ventricular fibrillation (VF) during reperfusion (rVF) in ST-segment elevation myocardial infarction (STEMI) is an infrequent but serious event that complicates coronary interventions. The aim of this study was to analyze clinical predictors of rVF in an unselected population of patients with STEMI treated with percutaneous coronary intervention (PCI). Consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2012 were retrospectively assessed for the presence of rVF. Admission electrocardiograms, stored in a digital format, were analyzed for a maximal ST-segment elevation in a single lead and the sum of ST-segment deviations in all leads. Clinical, electrocardiographic, and angiographic characteristics were tested for associations with rVF using logistic regression analysis. Among 3,724 patients with STEMI admitted from 2007 to 2012, 71 (1.9%) had rVF. In univariate analysis, history of myocardial infarction, aspirin and β-blocker use, VF before PCI, left main coronary artery disease, inferior myocardial infarction localization, symptom-to-balloon time <360 minutes, maximal ST-segment elevation in a single lead >300 μV, and sum of ST-segment deviations in all leads >1,500 μV were associated with increased risk for rVF. In a multivariate analysis, sum of ST-segment deviations in all leads >1500 μV (odds ratio 3.7, 95% confidence interval 1.45 to 9.41, p = 0.006) before PCI remained an independent predictor of rVF. In-hospital mortality was 18.3% in the rVF group and 3.3% in the group without VF (p <0.001), but rVF was not an independent predictor of in-hospital death. In conclusion, the magnitude of ST-segment elevation before PCI for STEMI independently predicts rVF and should be considered in periprocedural arrhythmic risk assessment. Despite higher in-hospital mortality in patients with rVF, rVF itself has no independent prognostic value for prognosis., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Rate control of atrial fibrillation (AF) is a main treatment modality. However, data are scarce on the relative efficacy of calcium channel blockers and β blockers or between drugs within each class. The purpose of the present study was to compare the effect of 4 rate-reducing, once-daily drug regimens on the ventricular heart rate and arrhythmia-related symptoms in patients with permanent AF. We included 60 patients (mean age 71 ± 9 years, 18 women) with permanent AF in an investigator-blind cross-over study. Diltiazem 360 mg/day, verapamil 240 mg/day, metoprolol 100 mg/day, and carvedilol 25 mg/day were administered for 3 weeks in a randomized sequence. The 24-hour heart rate was measured using Holter monitoring, and arrhythmia-related symptoms were assessed using the Symptom Checklist questionnaire before randomization and on the last day of each treatment period. The 24-hour mean heart rate was 96 ± 12 beats/min at baseline (no treatment), 75 ± 10 beats/min with diltiazem, 81 ± 11 beats/min with verapamil, 82 ± 11 beats/min with metoprolol, and 84 ± 11 beats/min with carvedilol. All drugs reduced the heart rate compared to baseline (p <0.001 for all). The 24-hour heart rate was significantly lower with diltiazem than with any other drug tested (p <0.001 for all). Compared to baseline, diltiazem significantly reduced both the frequency (p <0.001) and the severity (p = 0.005) of symptoms. In contrast, verapamil reduced symptom frequency only (p = 0.012). In conclusion, diltiazem 360 mg/day was the most effective drug regimen for reducing the heart rate in patients with permanent AF. Arrhythmia-related symptoms were reduced by treatment with the calcium channel blockers diltiazem and verapamil, but not by the β blockers., (Copyright © 2013 Elsevier Inc. All rights reserved.)