Radiofrequency ablation of cardiac fat pad at right pulmonary vein-atria junction attenuates Bezold-Jarisch reflex in canine / 第二军医大学学报

ABSTRACT

Objective: To observe the influence of radiofrequency catheter ablation of the fat pad at the right pulmonary veinatria junction (RPV fat pad) on Bezold-Jarisch reflex (BJR) induced by veratridine in canine. Methods: Ten mongrel dogs were anesthetized and their chest were opened through a right thoracotomy to expose the RPV fat pad. Veratridine was injected into the left ventricle at bolus doses of 10 μg/kg through a catheter to induce BJR. The sinus cycle length (SCL), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), left ventricle systolic pressure (LVSP), left ventricle diastolic pressure (LVDP) and mean left ventricle pressure (MLVP) were measured under the baseline and after ablation of the RPV fat pad; the changes of the above parameters (ΔSCL, ΔSAP, ΔAP, ΔMAP, ΔLVSP, ΔLVDP, and ΔMLVP) were calculated. Then the same dose of veratridine was injected under the pad after ablation and the changes of the above parameters were observed. Results: BJR was successfully induced in the 8 animals; the animals has prolonged sinus cycle length (SCL) and decreased MAP and MLVP. After ablation, the prolongation of SCL after injection of veratridine was markedly reduced ([229.2±92.3] ms vs [39.3±14.1] ms,P<0.01). All the pressures were decreased after injection of veratridine, with significant decrease found only for DAP and MAP (both P<0.05). Conclusion: Ablation of the RPV fat pad can effectively attenuate the decrement of heart rate and the decrement of DAP and MAP during the BJR induced by veratridine, which provides a basis for the radiofrequency catheter ablation of vagus ganglions through endocardium.