Effect of Left Atrial Wall Thickness on Radiofrequency Ablation Success.

INTRODUCTION: Radiofrequency (RF) ablation in thicker regions of the left atrium (LA) may require increased ablation energy in order to achieve effective transmural lesions. Consequently, many cases of recurrent atrial fibrillation (AF) postablation may be due to thicker-than-normal atrial tissue. The aim of this study was to test the hypotheses that patients with recurrent AF have thicker tissue overall and that electrical reconnection is more likely in regions of thicker tissue. METHODS AND RESULTS: Retrospective analysis was performed on 86 CT images acquired preoperatively from a cohort of 119 patients who had undergone RF ablation for AF. Of these, 33 patients experienced recurrence of AF within 1 year of initial treatment and 29 returned for a repeat ablation. For each patient, LA wall thickness (LAWT) was measured from the images in 12 anatomical regions using custom software. Patients with recurrent AF had larger LAWT compared to successfully treated patients (1.6 ± 0.6 mm vs. 1.5 ± 0.5 mm, P \u3c 0.001) and reconnection was found to be at regions of thicker tissue (1.6 ± 0.6 mm, P = 0.038) compared to nonreconnected regions (1.5 ± 0.5 mm). The superior right posterior wall of the LA was significantly related to both recurrence (P = 0.048) and reconnection (P = 0.014). CONCLUSION: Increased LAWT has a small but significant effect on postablation recurrence and reconnection. Measures of LAWT may facilitate appropriate dosing of RF energy, but other factors will be critical in transmural lesion formation and ablation success

How to diagnose the cause of sudden cardiac arrest

Sudden cardiac death or sudden cardiac arrest (SCA) is defined as natural death that occurs within an hour of the onset of acute symptoms or during sleep due to a primary cardiac cause. Most cases of SCA are attributable to coronary artery disease, with occult cardiomyopathy or inheritable arrhythmic syndromes accounting for a minority of SCA. Diagnosing the cause of SCA has potential implications for the patient and the family, and demands a comprehensive approach. This review summarizes the potential causes of SCA and outlines a systematic diagnostic approach to the SCA survivor. (Cardiol J 2011; 18, 2: 210-216

Cardiovascular implantable electrophysiological device-related infections: a review

Purpose of revie

Fused Whole-Heart Coronary and Myocardial Scar Imaging Using 3-T CMR: Implications for Planning of Cardiac Resynchronization Therapy and Coronary Revascularization

Objectives: The aim of this study was to demonstrate the feasibility of providing spatially matched, 3-dimensional (3D) myocardial scar and coronary imaging for the purpose of fused volumetric image display in patients undergoing cardiac resynchronization therapy (CRT) or coronary artery revascularization (CAR). Background: Clinical success in coronary vascular-based interventions is mitigated by the presence of scar in related myocardium. Pre-procedural fused volumetric imaging of both myocardial scar and coronary vasculature may benefit pre-procedural planning and patient selection in populations referred for CRT or CAR. Methods: A total of 55 studies were performed in patients referred for either CRT (n = 42) or CAR (n = 13). Coronary-enhanced and scar-enhanced imaging was performed on a 3-T cardiac magnetic resonance scanner using the same cardiac-gated, 3D, free-breathing cardiac magnetic resonance technique during and 20 minutes following slow gadolinium infusion. Matched image datasets were fused and volume-rendered to simultaneously display coronary anatomy and myocardial scar. Visual scoring of coronary artery, coronary vein, and myocardial scar image quality (score 0 to 4) was performed. The clinical impact of imaging was also scored using a physician survey. Results: Mean age was 57 ± 14 years. Combined 3D coronary and scar imaging was successful in 49 studies (89%). A quality score ≥2 was obtained for 97% of proximal- and mid-coronary artery and vein segments. The mean quality score of 3D scar imaging was 2.8 ± 1.0 and was scored as ≥2 in 86% of patients with myocardial scar. All patients with a scar quality score ≥2 achieved successful image fusion. Transmural scar was present below ≥1 planned target vessel in 9 patients (39%) planned for CRT and 8 patients (62%) planned for CAR. Physician surveys demonstrated incremental clinical impact in 67% of patients. Conclusions: Three-dimensional myocardial scar and coronary imaging with fused volumetric display is clinically feasible and may be valuable for the planning of vascular-based interventions when regional myocardial scar is pertinent to therapeutic success