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Background: Patients with hypertrophic cardiomyopathy (HCM) are at risk of sudden death, and individuals with ≥1 major risk markers are considered for primary prevention implantable cardioverter-defibrillators. Guidelines recommend cardiac magnetic resonance (CMR) imaging to identify high-risk imaging features. However, CMR imaging is resource intensive and is not widely accessible worldwide., Objective: The purpose of this study was to develop electrocardiogram (ECG) deep-learning (DL) models for the identification of patients with HCM and high-risk imaging features., Methods: Patients with HCM evaluated at Tufts Medical Center (N = 1930; Boston, MA) were used to develop ECG-DL models for the prediction of high-risk imaging features: systolic dysfunction, massive hypertrophy (≥30 mm), apical aneurysm, and extensive late gadolinium enhancement. ECG-DL models were externally validated in a cohort of patients with HCM from the Amrita Hospital HCM Center (N = 233; Kochi, India)., Results: ECG-DL models reliably identified high-risk features (systolic dysfunction, massive hypertrophy, apical aneurysm, and extensive late gadolinium enhancement) during holdout testing (c-statistic 0.72, 0.83, 0.93, and 0.76) and external validation (c-statistic 0.71, 0.76, 0.91, and 0.68). A hypothetical screening strategy using echocardiography combined with ECG-DL-guided selective CMR use demonstrated a sensitivity of 97% for identifying patients with high-risk features while reducing the number of recommended CMRs by 61%. The negative predictive value with this screening strategy for the absence of high-risk features in patients without ECG-DL recommendation for CMR was 99.5%., Conclusion: In HCM, novel ECG-DL models reliably identified patients with high-risk imaging features while offering the potential to reduce CMR testing requirements in underresourced areas., Competing Interests: Disclosures Dr Maron is a consultant for Cytokinetics, iRhythm, Imbria Pharmaceuticals, and Takeda Pharmaceuticals. Dr Rowin has received research funding from Pfizer and iRhythm. The remaining authors have nothing to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

His bundle pacing (HBP) has recently emerged as a technique to avoid the negative effects of long-term right ventricular apical pacing. In addition to providing physiologic ventricular activation, HBP has been shown to correct underlying conduction abnormalities in certain patients. Although large prospective, randomized clinical trials have not yet been completed, the available observational clinical data support the safety and efficacy of this technique. Here, we review the physiology of the his bundle (HB) as it relates to HBP, describe the current clinical experience, and discuss future directions of this emerging therapy.

Background: Stress cardiomyopathy (SCM) is a syndrome of transient ventricular dysfunction triggered by severe emotional or physical stress, likely resulting from catecholamine-mediated myocardial toxicity. Repolarization abnormalities associated with other hyperadrenergic states can cause QT prolongation and lethal arrhythmia including torsades de pointes (TdP). Despite the development of repolarization abnormalities and QT prolongation in SCM, little is known about the risk of ventricular fibrillation (VF) and TdP., Objective: The aim of this study was to assess the prevalence and clinical predictors of ventricular arrhythmias in a cohort of patients with SCM., Methods: Data from a registry of consecutive patients with SCM from 2 institutions were reviewed. Patients who developed VF or TdP were identified. Clinical characteristics and outcomes were analyzed and compared with a control group of patients with SCM without VF/TdP., Results: Of 93 patients with SCM, 8 (8.6%) experienced VF/TdP. Of these 8 patients, 2 presented with VF and were subsequently diagnosed with SCM. Six other patients experienced pause-dependent TdP or VF after SCM diagnosis in the setting of substantial QT prolongation. Prolongation of the corrected QT interval (QTc) was significantly associated with the occurrence of ventricular arrhythmia (odds ratio 1.28 for each 10 ms increase in QTc, 95% confidence interval 1.10 to 1.50)., Conclusion: SCM can be associated with life-threatening ventricular arrhythmia in over 8% of cases. SCM should be recognized among the causes of acquired long QT syndrome and can be associated with a risk of TdP., (Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

The article describes the case of wide complex tachycardia in a 20-year-old female with history of congenital complete heart block and patent ductus arteriosus status post coil embolization at age 10. Topics discussed include the mechanism of the wide complex rhythm, the results of the patient's telemetry and electrocardiogram, and ablation at the site of earliest ventricular activation on the anterolateral mitral annulus.

Cardiac tumors can lead to distinct electrocardiographic changes and ventricular arrhythmias. Benign and malignant cardiac tumors have been associated with ventricular tachycardia. When possible, benign tumors should be resected when ventricular arrhythmias are intractable. Chemotherapy can shrink malignant tumors and eliminate arrhythmias. We report the case of a 52-year-old woman with breast sarcoma whom we diagnosed with myocardial metastasis after she presented with palpitations. The initial electrocardiogram revealed sinus rhythm with new right bundle branch block and ST-segment elevation in the anterior precordial leads. During telemetry, hemodynamically stable, sustained ventricular tachycardia with right ventricular localization was detected. Images showed a myocardial mass in the right ventricular free wall. Amiodarone suppressed the arrhythmia. To our knowledge, this is the first report of ventricular tachycardia associated with radiation-induced undifferentiated sarcoma. We discuss the distinct electrocardiographic changes and ventricular arrhythmias that can be associated with cardiac tumors, and we review the relevant medical literature. [ABSTRACT FROM AUTHOR]