Radiofrequency ablation of drug refractory ventricular tachycardia related to cocaine use: a feasibility, safety, and efficacy study.

BACKGROUND: Cocaine use is a known but rare cause of cardiac arrhythmias. Ventricular arrhythmias related to cocaine may not respond to antiarrhythmic drugs and may need treatment with radiofrequency ablation. OBJECTIVES: We describe the clinical and electrophysiological characteristics of cocaine-related ventricular tachycardia (VT) from a multicenter registry. METHODS: Subjects presenting with VT related to cocaine use and being considered for radiofrequency ablation have been included in the study. Patients who were refractory to maximal medical therapy underwent radiofrequency ablation of the VT. Clinical, procedural variables, efficacy, and safety outcomes were assessed. RESULTS: A total of 14 subjects met study criteria (age 44 ± 13, range 18- to 68-year-old with 79% male, 71% Caucasian). MRI showed evidence of scar only in 43% of patients (6/14). The mechanism of VT was focal in 50% (n = 7) and scar related reentry in 50% (n = 7) based on 3D mapping. The mean VT cycle length was 429 ± 96 milliseconds. The site of origin was epicardial in 16% (3/18) of VTs. Most clinical VTs were hemodynamically stable (75%). Mean ejection fraction at the time of admission was 44 ± 14%. Duration of procedure was 289 ± 50 minutes. One subject developed pericardial tamponade requiring drainage. At 18 ± 11 months follow-up, freedom from arrhythmia was seen in 86% (1 case lost to follow-up and 2 died). CONCLUSION: Radiofrequency ablation is not only feasible but also safe and effective in patients who have drug refractory VT related to chronic cocaine use.

The role of percutaneous left ventricular assist devices during ventricular tachycardia ablation.

Ventricular tachycardia (VT) is a common but serious arrhythmia that significantly adds to the morbidity and mortality of patients with structural heart disease. Percutaneous catheter ablation has evolved to be standard therapy to prevent recurrent implantable cardioverter defibrillator shocks from VT in patients on antiarrhythmia medications. Procedural outcomes in patients with structural heart disease are often limited by haemodynamically unstable VT. Although substrate- and pace-mapping techniques have become increasingly popular for VT ablation, these approaches can often times may not address inducible clinical and non-clinical VTs. Activation and entrainment mapping can help the operator target VT exit sites in a precise fashion minimizing the amount of radiofrequency ablation needed for a successful ablation. An evolving alternative strategy that allows induction and mapping of VT in the setting of severe cardiomyopathy and haemodynamic instability is through maintaining perfusion with a percutaneous ventricular assist device (pVAD). This review will discuss these pVAD technologies, distinguish technical applications of use, highlight the published clinical experience, provide a clinical approach for support device selection, and discuss use of these technologies with current mapping and navigational systems.

Remote Magnetic Navigation System Guided Radiofrequency Ablation of Intra Atrial Reentrant Tachycardia in Corrected Transposition of Great Arteries.

Atrial arrhythmias are delayed manifestations after atrial switch procedures for d-transposition of the great arteries. Often times, these arrhythmias are intraatrial reentry tachycardias that arise in the pulmonary venous neo-atrium. Access and ablation in the pulmonary venous neo-atrium may require baffle puncture, risking damage to the baffle. We describe a case of neoatrial arrhythmia ablation in d-transposition of the great arteries using remote magnetic guided catheter navigation system using a retrograde approach without doing a baffle puncture.

Left Atrial Volume and Post-Operative Atrial Fibrillation after Aortic Valve Replacement.

Post-operative atrial fibrillation (POAF) after valve surgery is associated with increased morbidity and mortality. Risk factors identified in the past to predict POAF are of moderate accuracy. We performed a retrospective analysis of 139 patients undergoing aortic valve replacement for aortic stenosis. Post-operative AF occurred in 44% of the patients. In multivariate analysis only left atrial volume (LAV) index was a predictor of POAF. A LAV index of >46 cc/m2 predicted POAF with a sensitivity and specificity of 92% and 77%. We propose that LAV index can be used preoperatively to identify patients at risk for POAF to target preventive interventions. Background: Post-operative atrial fibrillation (POAF) is common after valve surgery and is associated with increased morbidity and mortality. Many of the previously identified predictors of POAF are of moderate accuracy. Left atrial volume (LAV) index has been proposed in the past as a predictor of POAF in patients undergoing cardiac surgery. In patients with aortic stenosis (AS), increased LAV is a marker of severity of stenosis. Hypothesis: Left atrial volume index is a very good predictor of POAF in patients undergoing aortic valve replacement (AVR) for AS. Methods: We performed a retrospective analysis of 139 consecutive patients with no previous atrial fibrillation (AF) undergoing AVR for AS in our center. Results: Post-operative AF occurred in 44% of patients. Patients with POAF had a longer hospital stay compared to patients without (12 vs 8 days; p < 0.001). In univariate analysis, age (p = 0.046), aortic valve area (p = 0.005) and LAV index (p < 0.001) were significant predictors of POAF. In multivariate analysis only LAV index (R2= 0.58; p < 0.001) predicted POAF. A LAV index > 46ml/m2 predicted POAF with a sensitivity and specificity of 92% and 77% respectively. Moreover, there was a significant increase in the incidence of POAF with increasing quartiles of LAV index, supporting causality. Conclusion: Left atrial volume index is an excellent predictor of POAF in patients undergoing AVR for AS. It can be used for selecting patients who are at a high risk for developing POAF to target preventive interventions.