Chandrasekhar R. Vasamreddy

Initial experience in the use of integrated electroanatomic mapping with three-dimensional MR/CT images to guide catheter ablation of atrial fibrillation.

Introduction: No prior studies have reported the use of integrated electroanatomic mapping with preacquired magnetic resonance/computed tomographic (MR/CT) images to guide catheter ablation of atrial fibrillation (AF) in a series of patients.

Predictors of Recurrence Following Catheter Ablation of Atrial Fibrillation Using an Irrigated‐Tip Ablation Catheter

Introduction: The aims of this study were to identify predictors of recurrence after catheter ablation of atrial fibrillation (AF) and to report the safety and efficacy of catheter ablation of AF using an irrigated‐tip ablation catheter.

Long‐Term Safety and Efficacy of Circumferential Ablation with Pulmonary Vein Isolation

Background: Each of the two main approaches to catheter ablation of atrial fibrillation (AF, segmental and circumferential) is associated with moderate long‐term efficacy.

Characterization of a new pulmonary vein variant using magnetic resonance angiography: incidence, imaging, and interventional implications of the "right top pulmonary vein".

Introduction: Catheter ablation of the pulmonary veins (PVs) for prevention of recurrent atrial fibrillation requires precise anatomic information. We describe the characteristics of a new anatomic variant of PV anatomy using magnetic resonance angiography.

Atrial Volume Reduction Following Catheter Ablation of Atrial Fibrillation and Relation to Reduction in Pulmonary Vein Size: An Evaluation Using Magnetic Resonance Angiography

Introduction: Catheter ablation to achieve pulmonary vein (PV) isolation has become an increasingly used treatment strategy for patients with atrial fibrillation (AF). The purpose of this study was to evaluate the impact of segmental isolation of PVs on volume of left atrium and its relation to the decrease in the size of the pulmonary veins.Methods: Gadolinium enhanced Magnetic Resonance Angiography (MRA) was performed in 51 AF patients before and 6 ~ 8 weeks post PV isolation, using cooled radio-frequency (RF) energy. Three-dimensional reconstruction with maximum intensity projections and multiplanar reformations was performed. Oblique coronal projections were used to measure the ostial size of PVs. Three orthogonal dimensions of LA chamber were measured and computed to assess the volume of the left atrium.Results: The mean LA volume decreased by 15.7% after ablation (p < 0.001). The mean PV ostial diameter decreased by 11%, from 18.3 ± 0.8 mm to 16.7 ± 1.0 mm (p = 0.005). Moderate PV stenosis was noted in two veins out of the 192 veins analyzed. There was a significant correlation between changes in the size of PV ostium to that of the LA.Conclusions: Catheter ablation of AF using a segmental PV isolation approach results in a significant reverse remodeling in the left atrium. Significant stenosis of PVs appears to be rare after the segmental isolation procedure.

Electrical disconnection of the superior vena cava from the right atrium

A 39-year-old man presented with a 2-year history of frequent, symptomatic, paroxysmal atrial fibrillation (AF). After not responding to multiple antiarrhythmic drugs, he underwent a successful pulmonary vein (PV) isolation procedure. His symptoms resolved for a few weeks but then recurred. A second ablation procedure was performed 6 months later. Mapping of the PVs demonstrated their continued isolation. Mapping of the superior vena cava (SVC) in conjunction with the second ablation procedure using a 64-pole basket catheter showed active SVC potentials. The left panel of the figure shows bipolar electrograms recorded from the electrodes (numbered 1–8) on the eight spines (labeled A–H) of the 64-pole basket catheter. Application of RF energy to a single site in the low posterior SVC wall (orthogonal fluoroscopic images in the right panel; CS = coronary sinus)