Pacemaker Explantation in Patients With Lyme Carditis.

Early recognition of Lyme carditis is critical to preventing unnecessary pacemaker implantation for conduction abnormalities associated with this tick-born infection. Patients who do receive a pacemaker should be considered for device extraction after the completion of their antibiotic therapy if they recover normal atrioventricular node conduction. (Level of Difficulty: Intermediate.).

Transcatheter Compared With Surgical Aortic Valve Replacement in Patients With Previous Chest-Directed Radiation Therapy.

BACKGROUND: Cardiac surgery for radiation-induced valvular disease is associated with adverse outcomes. Transcatheter aortic valve replacement (TAVR) is increasingly used in patients with a history of chest-directed radiation therapy and aortic stenosis (CRT-AS). OBJECTIVES: We examined outcomes of TAVR compared with surgical aortic valve replacement (SAVR) for patients with CRT-AS. METHODS: We identified 69 patients with CRT-AS who underwent TAVR from January 2012 to September 2018. Operative mortality, postoperative morbidities, and length of hospitalization were compared with 117 contemporaneous patients with CRT-AS who underwent isolated SAVR. Age-adjusted survival was evaluated by means of Cox proportional hazards modeling. RESULTS: Compared with SAVR patients, TAVR patients were older (mean age 75 ± 11.5 vs 65 ± 11.5 years), with more comorbidities, such as chronic obstructive pulmonary disease, atrial fibrillation, and peripheral vascular disease (all P < 0.050). Operative mortality was 4.3% for SAVR vs 1.4% for TAVR (P = 0.41). Most SAVR deaths (4 of 5) occurred in the intermediate-/high-risk group (Society for Thoracic Surgeons predicted risk of operative mortality >3%; P = 0.026). The ratio of observed to expected mortality was better for low-risk SAVR patients and all TAVR patients (0.72 [95% confidence interval [CI]: 0.59-0.86] and 0.24 [95% CI: 0.05-0.51], respectively) compared with intermediate-/high-risk SAVR patients (2.52 [95% CI: 0.26-4.13]). SAVR patients had significantly longer median intensive care unit and overall length of stay and higher blood transfusion requirements but similar rates of stroke and pacemaker implantation. CONCLUSIONS: TAVR was associated with excellent in-hospital outcomes and better survival compared with intermediate-/high-risk SAVR in patients with CRT-AS. While SAVR still has a role in low-risk patients or those for whom TAVR is unsuitable for technical or anatomical reasons, TAVR is emerging as the standard of care for intermediate-/high-risk CRT-AS patients.

Follow the Lead: The Challenges of Cardiogenic Shock in Device-Related Infective Endocarditis.

We present the challenging case of a young man with congenital heart disease who survived severe device-related infective endocarditis and new pulmonary hypertension. He required prolonged mechanical circulatory support and had multiple significant complications. His case posed a management dilemma that was successfully resolved by effective multidisciplinary, tertiary center care. (Level of Difficulty: Beginner.).

Rhythm disturbances following rapid-deployment aortic valve replacement.

OBJECTIVES: There have been reports of postoperative conduction disturbances after rapid-deployment aortic valve replacement. Our objective was to assess electrocardiogram changes in patients undergoing this procedure and review the literature on this topic. METHODS: In this retrospective case series, clinical data were extracted from patient records at St Vincent's Hospital Melbourne and the Australia New Zealand Society of Cardiac and Thoracic Surgeons database. Electrocardiogram data were obtained at baseline and postoperatively on day 5 and at week 6 and reviewed for rhythm disturbances and intracardiac conduction problems. Pacemaker status was also recorded. RESULTS: From 2013 to 2017, 100 consecutive patients underwent rapid-deployment aortic valve replacement with 1 valve type at our institution. Three patients were excluded because of paced rhythm preoperatively, leaving 97 patients (mean age 74.7 ± 8.12 years; 56.7% male) for analysis. Some 18.6% of patients developed new left bundle branch block at 5 days postoperatively and only 4.1% of patients found with persistent left bundle branch block at 6-week follow-up compared with preoperatively. No significant changes were observed in the frequencies of atrial fibrillation, first-degree heart block, and right bundle branch block. However, there was evidence of increases in paced rhythm and subsequent need for a permanent pacemaker. A total of 14 patients (14.4%) had a permanent pacemaker implanted at an average of 11.1 ± 2.9 days postoperatively. CONCLUSIONS: Rhythm disturbances and conduction abnormalities are noted with the rapid-deployment aortic valves used at our institution, but appear comparable to other rapid-deployment aortic valve replacement bioprostheses. These abnormalities may be related to the effect of the sub-annular stent frame of the valve system and implantation technique.

Long-Term Outcomes of Surgical Ablation for Atrial Fibrillation: Impact of Ablation Lesion Sets.

Background: The lesion sets for surgical ablation of atrial fibrillation (AF) that provide optimal outcomes have remained controversial. Objectives: We evaluated the effects of left-atrial (LA) ablation of AF compared with bi-atrial (BA) ablation on the clinical and rhythm outcomes, and examined the predictors for AF recurrence and permanent pacing in consideration of ablation lesion sets. Methods: Between 2001 and 2018, 1,965 patients underwent surgical ablation during cardiac surgery at our institution. Among these, 796 and 1,169 patients underwent LA and BA ablation, respectively. The clinical outcomes were evaluated after propensity score adjustment, with death accounting for a competing event. The probability of AF recurrence was estimated with the generalized estimating equations model. Results: The patients with BA ablation had morbidities greater than those with LA ablation. The probability of AF recurrence at 1 and 5 years was 13.9% and 37.1% in patients with LA ablation, and 11.2% and 30.1% in those with BA ablation (hazard ratio [HR]: 1.24; 95% confidence interval [CI]: 0.96-1.61; P = 0.100). After adjustment, LA ablation was associated with a decreased risk of early death (<30 days) (odds ratio [OR]: 0.56; 95% CI: 0.31-0.96; P = 0.041) and new-onset dialysis (OR 0.47; 95% CI: 0.27-0.78; P = 0.003). However, the risk of overall mortality (HR: 1.03; 95% CI: 0.75-1.41; P = 0.878) and permanent pacing (HR: 0.68; 95% CI: 0.43-1.06; P = 0.091) was comparable between the 2 groups. Conclusions: The risk of AF recurrence and adverse events was comparable between the 2 ablation lesion sets. BA ablation was not related to an increased risk of permanent pacing.

Sequential Use of Aminophylline and Theophylline for Temporizing Neck Cancer-Induced Carotid Sinus Syncope.

Carotid sinus syncope due to head and neck cancer is uncommon and the management is challenging. Permanent pacemaker implantation is generally considered but malnutrition with subsequent chemo-radiation increases the risk of device infection. This is a first case report of the sequential use of aminophylline and theophylline for pharmacological temporization. (Level of Difficulty: Advanced.).

Aorto-Right Ventricular Fistula and Paravalvular Leak After Transcatheter Aortic Valve Implantation.

Aorto-right ventricular fistula is a potentially fatal complication following transcatheter aortic valve implantation (TAVI). This paper presents a case of successful percutaneous repair of aorto-right ventricular fistula and paravalvular leak after TAVI by using 3D-printed models for pre-procedural planning, and a review of published aorto-right ventricular fistula cases to date. (Level of Difficulty: Advanced.).

Facilitation of transvenous lead extraction using site-specific delivery of electrosurgical energy.

INTRODUCTION: Excimer laser energy is often required to extract chronically indwelling pacemaker and defibrillator leads from the vasculature and myocardium. This technique can be associated with vascular and right ventricular (RV) injuries. We sought to develop a safer, more effective method by applying site-specific delivery of electrosurgical energy (EE). METHODS: Utilizing a polyacrylamide gel model to simulate soft tissue density, active and passive fixation defibrillator and pacemaker leads were implanted and manually extracted with and without EE delivered to the cathode. The amount of force required for complete removal was measured using a force transducer. The procedure was then repeated in an acute pig model to demonstrate proof of safety. Post mortem gross and histologic specimens were collected from the implantation site. RESULTS: In the gel model, the force required for extraction, using manual traction in the active (83.7 g) and passive (74.6 g) fixation ICD leads, was reduced by 37.8% and 33.5%, respectively with EE (both p < 0.01). The force required for extraction, using manual traction in the active (85.2 g) and passive (71.9 g) fixation pacemaker leads, was reduced by 64.4% and 42.6%, respectively with EE (both p < 0.01). In an acute implantation pig model using an active fixation lead, delivery of EE to the cathode (n = 6) reduced the force required to manually extract the lead (140 g +/- 32.5 versus 82 g +/- 14.7, p = 0.03). Post mortem analysis of the RV displayed formation of an epicardial hemorrhagic lesion that was also present after manual traction and EE. There was absence of pericardial effusion, perforation, and ventricular arrhythmia. CONCLUSIONS: Site-specific delivery of EE to areas of exposed metal along the lead decreased the force necessary for lead extraction in an in vitro and in vivo model. Further studies are needed to evaluate its application in clinical care.