Early Ventricular Arrhythmias After Left Ventricular Assist Device Implantation.

BACKGROUND: Although sustained ventricular arrhythmias (VAs) are a common complication after durable left ventricular assist device (LVAD) implantation, the incidence, risk factors, and prognostic implications of postoperative early VAs (EVAs) in contemporary patients with LVAD are poorly understood. METHODS AND RESULTS: A single-center retrospective analysis was performed of patients who underwent LVAD implantation from October 1, 2006, to October 1, 2022. EVA was defined as an episode of sustained VA identified ≤30 days after LVAD implantation. A total of 789 patients underwent LVAD implantation (mean age 62.9 ± 0. years 5, HeartMate 3 41.4%, destination therapy 43.3%). EVAs occurred in 100 patients (12.7%). A history of end-stage renal disease (odds ratio [OR] 5.6, 95% confidence interval [CI] 1.45-21.70), preoperative electrical storm (OR 2.82, 95% CI 1.11-7.16), and appropriate implantable cardiac defibrillator therapy before implantation (OR 2.8, 95% CI 1.26-6.19) are independently associated with EVAs. EVA was associated with decreased 30-day survival (hazard ratio 3.02, 95% CI 1.1-8.3, P = .032). There was no difference in transplant-free survival time between patients with and without EVAs (hazard ratio 0.82, 95% CI 0.5-1.4, P = .454). CONCLUSIONS: EVAs are common after durable LVAD implantation and are associated with an increased risk of 30-day mortality.

Dual-chamber leadless pacing: Atrioventricular synchrony in preclinical models of normal or blocked atrioventricular conduction.

BACKGROUND: Dual-chamber leadless pacemakers (LPs) require robust communication between distinct right atrial (RA) and right ventricular (RV) LPs to achieve atrioventricular (AV) synchrony. OBJECTIVE: The purpose of this preclinical study was to evaluate a novel, continuous implant-to-implant (i2i™) communication methodology for maintaining AV-synchronous, dual-chamber DDD(R) pacing by the 2 LPs. METHODS: RA and RV LPs were implanted and paired in 7 ovine subjects (4 with induced complete heart block). AV synchrony (% AV intervals <300 ms) and i2i communication success (% successful i2i transmissions between LPs) were evaluated acutely and chronically. During acute testing, 12-lead electrocardiographic and LP diagnostic data were collected from 5-minute recordings, in 4 postures and 2 rhythms (AP-VP and AS-VP, or AP-VS and AS-VS) per subject. Chronic i2i performance was evaluated through 23 weeks postimplant (final i2i evaluation period: week 16-23). RESULTS: Acute AV synchrony and i2i communication success across multiple postures and rhythms were median [interquartile range] 100.0% [100.0%-100.0%] and 99.9% [99.9%-99.9%], respectively. AV synchrony and i2i success rates did not differ across postures (P = .59, P = .11) or rhythms (P = 1, P = .82). During the final i2i evaluation period, the overall i2i success was 98.9% [98.1%-99.0%]. CONCLUSION: Successful AV-synchronous, dual-chamber DDD(R) leadless pacing using a novel, continuous, wireless communication modality was demonstrated across variations in posture and rhythm in a preclinical model.

The combination of coronary sinus ostial atresia/abnormalities and a small persistent left superior vena cava-Opportunity for left ventricular lead implantation and unrecognized source of thromboembolic stroke.

BACKGROUND: Coronary sinus (CS) ostial atresia/abnormalities prevent access to the CS from the right atrium (RA) for left ventricular (LV) lead implantation. Some patients with CS ostial abnormalities also have a small persistent left superior vena cava (sPLSVC). OBJECTIVE: The purpose of this study was to describe CS ostial abnormalities and sPLSVC as an opportunity for LV lead implantation and unrecognized source of stroke. METHODS: Twenty patients with CS ostial abnormalities and sPLSVC were identified. Clinical information, imaging methods, LV lead implantation techniques, and complications were summarized. RESULTS: Forty percent had at least 1 previously unsuccessful LV lead placement. In 70%, sPLSVC was identified by catheter manipulation and contrast injection in the left brachiocephalic vein, and in 30% by levophase CS venography. In 30%, sPLSVC was associated with drainage from the CS into the left atrium (LA). When associated with CS ostial abnormalities, the sPLSVC diameter averaged 5.6 ± 3 mm. sPLSVC was used for successful LV lead implantation in 90% of cases. In 80%, the LV lead was implanted down sPLSVC, and in 20%, sPLSVC was used to access the CS from the RA. Presumably because of unrecognized drainage from the CS to the LA, 1 patient had a stroke during implantation via sPLSVC. CONCLUSION: When CS ostial abnormalities prevent access to the CS from the RA, sPLSVC can be used to successfully implant LV leads. In some, the CS partially drains into the LA and stroke can occur spontaneously or during lead intervention. It is important to distinguish sPLSVC associated with CS ostial abnormalities from isolated PLSVC.