Irrigated vs. Non-irrigated Catheters in the Ablation of Accessory Pathways.

There is a paucity of data comparing irrigated to non-irrigated catheters in the ablation of accessory pathways (AP) in adult patients. Retrospective analysis of first-time AP ablations performed at our institution from May 2010 to June 2017. A total of 69 AP ablations were studied; irrigated catheters were used in 78.3% cases. Mean age was 40.9 ± 14.3 years and 56.7% were male. Among APs, 63.8% were left sided and 56.5% were concealed. The total procedure time was 232.0 ± 89.0 min, ablation time was 3.1 ± 5.1 min, and fluoroscopy time was 13.9 ± 15.4 min. The overall acute success rate of ablation was 62/69 (89%). Success rates trended higher with irrigated catheters in both groups and were significant for the population as a whole (94.4% vs. 73.3%, p = 0.04). Analyzing the entire cohort, success rates were significantly higher in ablations using irrigated catheters.

Strength duration curve for epicardial left ventricular stimulation.

BACKGROUND: The strength duration curve for endocardial stimulation has been extensively studied. Little information is available on the left ventricular epicardial strength duration curve. In view of the large number of patients treated with resynchronization therapy, left ventricular epicardial stimulation parameters have practical importance. METHODS: Twelve patients who underwent implant of a biventricular defibrillator were available for at least 4 months of follow up and accurate determination of strength duration curves were studied. Strength duration curves were constructed at 30 days (subacute phase) and 4 or more months (chronic phase) after the implant for right ventricular endocardial, left ventricular epicardial unipolar, and left ventricular bipolar stimulation. The goal was to determine the chronaxie, which correlates with the most economical stimulation. RESULTS: There was no significant difference between the right ventricular endocardial and left ventricular epicardial bipolar chronaxie (P = 0.57 subacute and 0.6 chronic) or right ventricular endocardial and left ventricular unipolar chronaxie (P = 0.93 subacute and 0.92 chronic). Most chronaxie values were lower than the factory default values. CONCLUSION: The left ventricular unipolar or bipolar epicardial chronaxie is not significantly different from the right ventricular endocardial chronaxie. Both values are lower than the pulse duration used as default setting in most devices as well as in clinical practice. Individual determination of the chronaxie could lead to energy savings.