LIFE-THREATENING ARRHYTHMIAS AND RV DYSFUNCTION AFTER SURGICAL REPAIROF TETRALOGY OF FALLOT - COMPARISON BETWEEN TRANSVENTRICULAR AND TRANSATRIAL APPROACHES

Background Late postoperative arrhythmias and right ventricular dysfun ction may occur after classic repair of tetralogy of Fallot. Methods a nd Results During a mean follow-up of 8.9 years (range, 5 to 14 years) , 24-hour ambulatory electrocardiographic studies were done in 107 pat ients after repair of tetralogy of Fallot. Radionuclide angiography wa s performed in 97, and 78 patients also underwent postoperative heart catheterization. The patients were divided into two groups: group A co nsisted of 71 patients aged 2 months to 61 years (mean, 6.8 years) in whom the right ventricular approach was used; group B included 36 pati ents aged 8 months to 39 years (mean, 7.9 years) whose repair was thro ugh the right atrium. A transannular patch was employed in 42 (59.2%) patients in group A and in 23 (63.9%) patients in group B. Eighteen pa tients were adults (>18 years old) at the time of surgery: 13 (18.3%) in group A and 5 (13.8%) in group B. During a mean follow-up of 9.7 ye ars, 57 (80.3%) group A patients were in New York Heart Association (N YHA) functional class I. Atrial flutter was present in 3 (4.2%) patien ts, and 28 (39.4%) had significant ventricular arrhythmias (greater th an or equal to Lown grade 2). Postoperative heart catheterization show ed good hemodynamic results in 36 of 54 group A patients studied (12 o f whom had ventricular arrhythmias); moderate-to-severe pulmonary regu rgitation was present in 14 (25.9%) patients; only 2 (3.7%) patients h ad right ventricular hypertension. On electrophysiological study, 8 of 28 (28.6%) patients in group A had inducible sustained ventricular ta chycardia. Despite antiarrhythmic therapy, 2 of these patients died su ddenly, presumably from ventricular arrhythmias. Two other late deaths in group A were caused by heart failure. During a mean follow-up of 7 .2 years, 33 of 36 (91.7%) patients in group B were in NYHA functional class I. Atrial flutter was not found in any patient in this group. O nly 1 (2.8%) patient, who had moderate-to-severe pulmonary regurgitati on, had significant ventricular arrhythmias (greater than or equal to Lown grade 2). Postoperative catheterization showed good hemodynamic r esults in 20 of 24 patients; 3 (12.5%) had moderate-to-severe pulmonar y regurgitation, and 1 (4.2%) patient had right ventricular hypertensi on. Sustained ventricular tachycardia could not be induced in any of t he 5 adult patients who underwent electrophysiological studies. One la te death (caused by endocarditis) occurred in group B. Conclusions The right atrial approach significantly reduced the risk of life-threaten ing ventricular arrhythmias after repair of tetralogy of Fallot (P<.00 1) without increasing the incidence of supraventricular arrhythmias. R ight ventricular dysfunction and severe pulmonary regurgitation were a lso more prevalent (P<.01) when the right ventricular approach was use d.