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Background: Catheter ablation is an effective treatment for ventricular arrhythmia (VA) in ischemic cardiomyopathy (ICM). However, results in non‐ICM (NICM) patients are not satisfactory, and studies comparing differences between NICM and ICM are limited. We conducted a meta‐analysis of procedural characteristics and long‐term outcomes of catheter ablation for VA, comparing results between ICM and NICM. Methods: Studies in the PubMed, EMBASE, and Cochrane databases were systematically reviewed. Four studies reporting comparison of catheter ablation of VA between ICM and NICM were examined. The Newcastle‐Ottawa Scale was used to appraise study quality. A random‐effects model with inverse variance method was used for comparisons. Results: Epicardial approach was significantly more undertaken for the NICM group than in the ICM group (odds ratio [OR]: 0.13; 95% confidence interval [CI]: 0.09‐0.18; P <.00001). Mean ablation time (P =.54), fluoroscopy time (P =.55), and procedural time (P =.18) did not differ significantly between the ICM and NICM groups. Procedural failure rates (OR: 0.46; 95% CI: 0.24‐0.89; P =.02) and VA recurrence rates (risk ratio [RR]: 0.68; 95% CI: 0.46‐1.01; P =.06) were significantly higher in the NICM group than in the ICM group. However, all‐cause mortality (RR: 1.37; 95% CI: 0.75‐2.49; P =.31) did not differ significantly between groups. Conclusions: Procedural failure and VA recurrence rates were significantly higher in the NICM group, despite significantly more frequent epicardial access. These highlight the limitations of catheter ablation for VA in NICM, given our current knowledge. [ABSTRACT FROM AUTHOR]

Background: Atrioventricular nodal reentrant tachycardia (AVNRT) is treatable by catheter ablation. Advances in mapping‐system technology permit fluoroless workflow during ablations. As national practice trends toward fluoroless approaches, easily obtained, reproducible methods of slow‐pathway identification, and ablation become increasingly important. We present a novel method of slow‐pathway identification and initial ablation results from this method. Methods and Results: We examined AVNRT ablations performed at our institution over a 12‐month period. In these cases, the site of the slow pathway was predicted by latest activation in the inferior triangle of Koch during sinus rhythm. Ablation was performed in this region. Proximity of the predicted site to the successful ablation location, complication rates, and patient outcomes were recorded. Junctional rhythm was seen in 40/41 ablations (98%) at the predicted site (mean, 1.3 lesions and median, 1 lesion per case). One lesion was defined as 5 mm of ablation. The initial ablation was successful in 39/41 cases (95%); in two cases, greater or equal to 2 echo beats were detected after the initial ablation, necessitating further lesion expansion. In 8/41 cases (20%), greater than one lesion was placed during initial ablation before attempted reinduction. Complications included one transient heart block and one transient PR prolongation. During follow‐up (median, day 51), one patient had lower‐extremity deep‐vein thrombosis and pulmonary embolus, and one had a lower‐extremity superficial venous thrombosis. There was one tachycardia recurrence, which prompted a redo ablation. Conclusions: Mapping‐system detection of late‐activation, low‐amplitude voltage during sinus rhythm provides an objective, and fluoroless means of identifying the slow pathway in typical AVNRT. [ABSTRACT FROM AUTHOR]

Introduction: Current methods for measuring voltage during radiofrequency (RF) ablation (RFA) necessitate turning off the ablation catheter. If voltage could be accurately read without signal attenuation during RFA, turning off the catheter would be unnecessary, allowing continuous ablation. We evaluated the accuracy of the Thermocool SMARTTOUCH catheter for measuring voltage while RF traverses the catheter. Methods and Results: We studied 26 patients undergoing RFA for arrhythmias. A 7.5F SMARTTOUCH catheter was used for sensing voltage and performing RFA. Data were collected from the Carto-3 3-dimensional mapping system. Voltages were measured during ablation (RF-ON) and immediately before or after ablation (RF-OFF). In evaluating the accuracy of RF-ON measurements, we utilized the RF-OFF measure as the gold standard. We measured 465 voltage signals. The median values were 0.2900 and 0.3100 for RF-ON and RF-OFF, respectively. Wilcoxon signed rank testing showed no significant difference in these values (P = 0.608). The intraclass correlation coefficient (ICC) was 0.96, indicating that voltage measurements were similarly accurate during RF-OFF versus RF-ON. Five patients had baseline atrial fibrillation (AF), for whom 82 ablation points were measured; 383 additional ablation points were measured for the remaining patients. The voltages measured during RF-ON versus RF-OFF were similar in the presence of AF (P = 0.800) versus non-AF rhythm (P = 0.456) (ICC, 0.96 for both). Conclusion: Voltage signal measurement was similarly accurate during RF-ON versus RF-OFF independent of baseline rhythm. Physicians should consider not turning off the SMARTTOUCH ablation catheter when measuring voltage during RFA. [ABSTRACT FROM AUTHOR]