HEMODYNAMIC DETERIORATION FOLLOWING RADIO FREQUENCY ABLATION OF THE ATRIOVENTRICULAR-CONDUCTION SYSTEM

Introduction. Radiofrequency ablation of the atrioventricular conducti on system has become an established therapy for patients with drug-ref ractory atrial fibrillation. We observed 14 patients with hemodynamic deterioration related to worsening of mitral regurgitation after the p rocedure. Patients and methods. We retrospectively evaluated 256 conse cutive patients with drug-refractory atrial fibrillation referred for radiofrequency ablation of the AV node and implantation of a pacemaker . Because we found hemodynamic deterioration related to worsening mitr al regurgitation, we compared the clinical history, electrophysiologic and echocardiographic data from the patients with hemodynamic deterio ration and worsening mitral regurgitation (group A) with those without hemodynamic deterioration (group B). Results. Fourteen out of 256 pat ients (group A) undergoing ablation of the atrioventricular conduction system deteriorated with acute pulmonary edema (3 patients) or conges tive heart failure (11 patients) at a mean of 6 weeks after the ablati on procedure. Four of these patients were referred for mitral valve su rgery. The length of the procedure and the number of applications duri ng ablation were similar in both groups. Compared with group B patient s, group A patients had significantly higher left ventricular end-dias tolic diameters (64 +/- 6 mm vs 56 +/- 9 mm; p < 0.05) at baseline des pite similar left ventricular end-systolic diameters, fractional short ening and grade of mitral regurgitation (1.15 +/- 1.05 vs 1.11 +/- 0.9 7). Moreover, whereas no change was observed in left ventricular end-d iastolic diameter, left ventricular end-systolic diameter, fractional shortening and grade of mitral regurgitation in group B patients after ablation, group A patients experienced a significant increase in left ventricular end-diastolic diameter (64 +/- 6 mm vs 72 +/- 9 mm; p < 0 .01) and grade of mitral regurgitation (1.15 +/- 1.05 vs 2.90 +/- 1.15 ; p < 0.01). In patients operated on no ablation related structural da mage to the mitral valve apparatus could be detected. The worsening of the mitral regurgitation was related to dilation of the mitral valve annulus. Conclusions. Hemodynamic deterioration together with progress ion of mitral regurgitation is a potential complication of ablation of the atrioventricular conduction system.