Background - Left Bundle Branch Pacing (LBBP) has recently emerged as a promising alternative modality for conduction system pacing. However, limited real-world data exists on the advantages and complications associated with LBBP. We analyzed the Rush conduction system pacing registry on LBBP to assess the success rates and complications associated with LBBP. Methods - All patients with an indication for pacing (PPM) or cardiac resynchronization therapy (CRT) that underwent LBBP for various reasons from 06/2018 to 04/2020 were included in the analysis. Results - A total of 57 of 59 patients underwent successful LBBP (success rate 97%). The average follow-up duration was 6.2 ± 5 months. The implanted devices included 38 dual-chamber pacemakers, 17 CRT defibrillators, and 2 CRT pacing systems. The most common reason for performing LBBP was a high His Bundle Pacing threshold (n = 23) at implant. The mean LBBP capture threshold at implant was 0.62 ± 0.21 V @ 0.4 ms which remained stable during follow up at 0.65 ± 0.68 V @ 0.4ms. In 21 patients with cardiomyopathy, there was a significant improvement in LVEF from 30 ± 11% to 42 ± 15%. A total of 7 lead-related complications (12.3%) were noted in the follow-up period. Three patients (5.3%) required lead revision during the follow-up period. Interventricular septal (IVS) perforation occurred (as late sequela) after 2 weeks in one patient. Conclusions - LBBP can be achieved with a high success rate and low capture thresholds. Left ventricular dysfunction improved significantly during follow-up. Lead-related complications were relatively common occurring in 12.3% of initially successful implants. Lead revision was required in 3 (5%) of patients.

The effect of feeding soybean protein isolate (SBP) diet or soybean protein isolate diet supplemented with 0.7% DL-methionine (SBP + Met) on mammary tumor progression was investigated. Sprague-Dawley female rats were fed from weaning a 20% casein (CAS) diet supplemented with 0.3% DL-methionine (AIN-76) and injected via jugular vein with N-nitrosomethylurea (NMU, 40 mg/kg body weight) at 7 wk of age. Five weeks after NMU treatment, animals were divided into the three isoenergetic, isoprotein diet groups: CAS (25 rats); SBP (26 rats) and SBP + Met (25 rats). First palpable mammary tumors were evident 8, 9 and 13 wk and the mean latency period was 13.30 +/- 1.23, 16.70 +/- 1.32 and 17.82 +/- 1.28 wk after NMU treatment in the CAS, SBP + Met and SBP diet groups, respectively. Tumor incidence was 80% in the CAS group compared with 42.3% in the SBP group (P = 0.01). Methionine supplementation increased tumor incidence to 64%. Total number and total weight of tumors was greater in the CAS group compared with either SBP + Met or SBP groups: 41 vs. 28 or 21 tumors and 97.28 g vs. 27.87 or 32.46 g, respectively. These data indicate that SBP diet, low in methionine content, fed 5 wk after carcinogen exposure significantly repressed mammary tumor progression. Methionine supplementation increased the number of animals with tumors but not the mean tumor weight.

The majority of embolic strokes in patients with nonvalvular atrial fibrillation are caused by thrombi in the left atrial appendage. It is projected that strokes related to atrial fibrillation will markedly increase in the future unless effective mitigation strategies are implemented. Systemic anticoagulation has been known to be highly effective in reducing stroke risk in patients with atrial fibrillation. However, bleeding complications and nonadherence are barriers to effective anticoagulation therapy. Surgical and percutaneous left atrial appendage occlusion devices are nonpharmacologic strategies to mitigate the challenges of drug therapy. We present a contemporary review of left atrial appendage occlusion for stroke prevention in nonvalvular atrial fibrillation. A thorough review of the history of surgical and percutaneous left atrial appendage occlusion devices, recent trials, and US Food and Drug Administration milestones of current left atrial appendage occlusion devices are discussed.

Chronotropic incompetence is the inability of the sinus node to increase heart rate commensurate with increased metabolic demand. Cardiac pacing alone may be insufficient to address exercise intolerance, fatigue, dyspnea on exertion, and other symptoms of chronotropic incompetence. Rate‐responsive (adaptive) pacing employs sensors to detect physical or physiological indices and mimic the response of the normal sinus node. This review describes the development, strengths, and limitations of a variety of sensors that have been employed to address chronotropic incompetence. A mini‐tutorial on programming rate‐adaptive parameters is included along with emphasis that patients' lifestyles and underlying medical conditions require careful consideration. In addition, special sensor applications used to respond prophylactically to physiologic signals are detailed and an in‐depth discussion of sensors as a potential aid in heart failure management is provided.

Introduction: Cryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the preferred modalities for catheter ablation of atrial fibrillation (AF). Technological advances have improved procedural outcomes, warranting an updated comparison. We sought to evaluate the efficacy and safety of CBA-2nd generation (CBA-2G) in comparison to RFA-contact force (RFA-CF) in patients with AF. Methods: MEDLINE, Cochrane, and ClinicalTrials.gov databases were searched until 03/01/2020 for relevant studies comparing CBA-2G versus RFA-CF in patients undergoing initial catheter ablation for AF. Results: A total of 17 studies, involving 11 793 patients were included. There was no difference between the two groups in the outcomes of freedom from atrial arrhythmia (p = .67) and total procedural complications (p = .65). There was a higher incidence of phrenic nerve palsy in CBA-2G (odds ratio: 10.7; 95% confidence interval [CI]: 5.85 to 19.55; p < .001). Procedure duration was shorter (mean difference: −31.32 min; 95% CI: −40.73 to −21.92; p < .001) and fluoroscopy duration was longer (+3.21 min; 95% CI: 1.09 to 5.33; p = .003) in CBA-2G compared to RFA-CF. In the subgroup analyses of patients with persistent AF and >1 freeze lesion delivered per vein, there was no difference in freedom from atrial arrhythmia. Conclusions: In AF patients undergoing initial ablation, CBA-2G and RFA-CF were equally efficacious. The procedure duration was shorter, but with a higher incidence of phrenic nerve palsy in CBA-2G. In patients with persistent AF, there was no difference in the efficacy between CBA-2G or RFA-CF techniques.