Single operator experience, learning curve, outcomes, and insights gained with conduction system pacing

BACKGROUND

Conduction system pacing (CSP) is increasingly utilized to prevent and correct dyssynchrony. Barriers to CSP adoption include limited training, methodologic variability, laboratory slot allocation, and few data on learning curves. We report learning curves/clinical outcomes from a single experienced electrophysiologist who was new to CSP, and share gained insights.

METHODS

Retrospective analysis of all patients who underwent attempted CSP implantation (2016-2023). Patient characteristics, ECGs, echocardiograms, fluoroscopy/procedure times, lead data were recorded at implant and follow-up.

RESULTS

CSP leads were implanted successfully in 167/191(87.4%) patients with a follow-up of 278 ± 378 days. His-bundle pacing (HBP = 59) and left-bundle-area pacing (LBAP = 108) had similar procedure/fluoroscopy times, QRS duration decreases, and ejection fraction improvements (all p > NS). Eight HBP lead revisions were required for high capture thresholds LBAP demonstrated lower pacing thresholds, higher lead impedances, and greater R-wave amplitudes at implant and follow-up. After 25 HBP cases, implant pacing thresholds, fluoroscopy, procedural times did not decrease. After 25 LBAP cases, there were significant decreases in all these parameters (p < 0.05). A separate analysis in LBAP patients with recorded Purkinje signals showed no differences in paced ECG characteristics between patients with pre- QRS Purkinje signals versus patients with Purkinje signals post-QRS onset.

CONCLUSIONS

Experienced implanters who are new to CSP can achieve steady-state procedural/fluoroscopy times after a learning curve of 25 implants. LBAP showed lower capture thresholds and higher success rates. Adequate depth of lead deployment (as determined by published parameters) does not require Purkinje potential to be pre-QRS. Operators new to CSP.can forego HBP and directly implement LBAP.

Sex differences in permanent pacemaker implantation after transcatheter aortic valve replacement: a systematic review and meta-analysis

BACKGROUND

There is limited evidence on the effect of sex on permanent pacemaker implantation (PPMI) after transcatheter aortic valve replacement (TAVR). The primary objective of this meta-analysis was to determine the role of sex among patients requiring PPMI post-TAVR.

METHODS

A literature search was conducted using the SCOPUS, MEDLINE, and CINAHL databases for studies published until October 2022. Eligible studies included published randomized controlled trials (RCTs) and Observational Cohort Studies (OCS) articles that reported PPMI as an outcome of pacemaker status following TAVR. This study was performed per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines. Publication bias was estimated using a Funnel plot and Egger's test. Data were pooled using a random-effects model. The primary endpoint was the sex difference in PPMI after TAVR, with odds ratios and 95% confidence intervals (CIs) extracted.

RESULTS

Data was obtained from 63 studies, and a total of 79,655 patients were included. The cumulative PPMI rate was 15.5% (95% CI, 13.6%-17.7%). The pooled analysis revealed that while there were more females than males undergoing TAVR (51.6%, 95% CI 50.4%-52.8%), males have a 14.5% higher risk for post-TAVR PPMI than females (OR 1.145, 95% CI 1.047-1.253, P < 0.01).

CONCLUSIONS

Males are more likely to experience PPMI after TAVR than females. Further research needs to be done to better explain these observed differences in outcomes.

Dyssynchronous Heart Failure: A Clinical Review

PURPOSE OF THE REVIEW

Dyssynchrony occurs when portions of the cardiac chambers contract in an uncoordinated fashion. Ventricular dyssynchrony primarily impacts the left ventricle and may result in heart failure. This entity is recognized as a major contributor to the development and progression of heart failure. A hallmark of dyssynchronous heart failure (HF_d) is left ventricular recovery after dyssynchrony is corrected. This review discusses the current understanding of pathophysiology of HF_d and provides clinical examples and current techniques for treatment.

RECENT FINDINGS

Data show that HF_d responds poorly to medical therapy. Cardiac resynchronization therapy (CRT) in the form of conventional biventricular pacing (BVP) is of proven benefit in HF_d, but is limited by a significant non-responder rate. Recently, conduction system pacing (His bundle or left bundle branch area pacing) has also shown promise in correcting HF_d. HF_d should be recognized as a distinct etiology of heart failure; HF_d responds best to CRT.

Multiple cutaneous and mucosal lesions in a patient with cocaine-levamisole-induced vasculopathy syndrome

Levamisole is an adulterant found in nearly 70% of cocaine in the United States. The concomitant use of levamisole and cocaine leads to a distinct clinical syndrome that typically manifests as agranulocytosis, leukocytoclastic vasculitis, and elevated antineutrophil cytoplasmic antibody (ANCA) levels. Systemic involvement has also been rarely reported with this syndrome. This is a case of a 51-year-old woman with chronic cocaine use who initially presented with multiple cutaneous ulcerations and was later found to have pulmonary and renal involvement. Infectious workup was unrevealing and autoimmune workup revealed highly elevated levels of perinuclear ANCA. Due to continuous cocaine use despite counseling, the patient was readmitted with worsening pulmonary and renal manifestations requiring initiation of immunosuppressive therapy.