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Background: Clinical studies have suggested that there is a significant correlation between left ventricular (LV) false tendon and premature ventricular complexes (PVCs)., Objective: This study aimed to investigate the electrophysiological characteristics and the outcome of radiofrequency catheter ablation (RFCA) for this category of PVCs., Methods: From a total of 2284 patients with idiopathic PVCs who underwent catheter ablation at 6 institutions in China, intracardiac echocardiography (ICE) was used during the procedure in 346 cases; 10 patients (2.9%) with PVCs associated with false tendon were retrospectively reviewed and enrolled in the present study. Activation mapping and pace mapping were performed to localize the origin of PVCs. ICE was used in all patients. If the false tendon was directly visualized and identified, we attempted to identify the distinct relationship with the PVC origin., Results: The PVCs were successfully eliminated by ablation in all patients. The target sites were confirmed to be related to false tendon. The origin of PVCs was located at the attachment of the false tendon to the papillary muscle, LV septum, or LV apex. At the target site, high-frequency Purkinje potentials were observed preceding local ventricular activation in 7 patients., Conclusion: LV false tendon can be associated with PVCs, which can be cured by RFCA. An ICE-guided electroanatomical approach should be considered to improve the safety and feasibility of this procedure., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background and Aims: Mitochondrial DNA (mtDNA) haplogroups have been associated with the development of coronary artery disease (CAD) in European populations. However, the specific mtDNA haplogroups associated with CAD have not been investigated in Chinese populations., Methods and Results: Here, we carried out a case-control study including 1036 and 481 CAD patients and 973 and 511 geographically matched asymptomatic control subjects in southern and northern China, respectively. After adjusting for age and gender, our results indicated that mtDNA haplogroups are not associated with the occurrence of CAD and its subcategories, acute coronary syndromes and stable coronary heart disease, in both southern and northern Chinese populations. By focusing on the southern Chinese population, we further revealed that mtDNA haplogroups are not associated with CAD severity. Type 2 diabetes (T2D) and hypertension are two key driving factors for the development of CAD, nonetheless, we found that the frequencies of the 12 studied mtDNA haplogroups did not differ between patients with and without T2D or hypertension., Conclusion: mtDNA haplogroups are not associated with the occurrence of CAD or its subcategories in Chinese populations. Other factors such as environment and nuclear genetic background may contribute to the occurrence of CAD., (Copyright © 2020 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.)

Background: Heart failure is common in patients with permanent pacemakers. Right ventricular (RV) pacing may worsen cardiac function, while the nonresponder rate of cardiac resynchronization therapy (CRT) for heart failure treatment remains 25%-30%., Objective: The purpose of this study was to assess clinical outcomes of upgrading to permanent His bundle pacing (pHBP) in patients with heart failure who underwent device upgrade from right ventricular pacing or CRT nonresponse., Methods: Eighteen patients with pacing-dependent heart failure and left ventricular ejection fraction (LVEF) <50% underwent pHBP attempts at device replacement. Of those 18 patients, 16 (88.9%) received pHBP successfully and followed for a mean of 36.2 months. All these patients underwent clinical evaluation, echocardiography, brain natriuretic peptide assay, and chest radiography immediately before replacement and during follow-up visits., Results: Of the 16 patients (mean age 70.6 ± 12.9 years; 9 [56.3%] men), 11 (68.8%) patients had pacing-induced cardiomyopathy (PICM) while the remaining 5 (31.2%) patients were CRT nonresponders. After upgrading to pHBP, QRS duration was significantly shortened (from 156.9 ± 21.7 to 107.1 ± 16.5 ms; P < .01). At 1-year follow-up after HBP, left ventricular end-diastolic dimensions decreased from baseline 62.3 ± 6.9 to 55.5 ± 7.7 mm (P < .01) and LVEF increased from baseline 35.7% ± 7.9% to 52.8% ± 9.6% (P < .01). Other improvements after HBP upgrade included mitral valve regurgitation, serum brain natriuretic peptide concentrations, cardiothoracic ratios, and New York Heart Association functional class (P < .01 for all)., Conclusion: In paced patients with clinically symptomatic heart failure and LVEF <50%, pHBP upgrade was feasible in 88.9%, with improved left ventricular function and remodeling. Hence, pHBP can be an alternative for patients with pacing-induced cardiomyopathy and CRT nonresponders., (Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

This report demonstrates the feasibility of pacing the left bundle branch (LBB) immediately beyond the conduction block to functionally restore the impaired His-Purkinje conduction system in a patient with heart failure and left bundle branch block (LBBB). The pacing required only a low pacing output (0.5 volts/0.5 ms) to correct the LBBB with accompanying right BBB on the electrocardiogram. Over 1-year of follow-up, the patient had a significant improvement in clinical outcome and echocardiographic measurements. The case shows a novel pacing strategy for patients with BBB that affects many patients with heart failure., (Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)