ELECTROPHYSIOLOGICAL DIAGNOSIS AND SURGIC AL-TREATMENT OF ATRIAL-FLUTTER

From 1982 to the late 1990 thirty-three patients with tachysystolic at rial fibrillation refractory to preventive antiarrhythmic therapy were examined and operated on. Invasive electrophysiological investigation was a must in the preoperative examination. The ''entrainment'' and ' 'adaptation'' effects of the refractory periods of different parts of the atria were estimated depending on the duration of the basic cycle of pacing. After provoking atrial flutter paroxysm the place of the ea rly appearance of A spike was determined and endocardial mapping was p erformed. During intraoperative mapping, the data of low-amplitude and fragmented activity were processed by a computer; the sequence of ele ctric activation of the atria was determined on flutter. 20 transthora cal operations with extracorporeal circulation were made. Of these, th ere were 7 operations of laser or cryogenic isolation of the AB node, 30 of laser photoablation, and 9 of cryodestruction of the arrhythmoge nic areas. In a female patient, resection of the terminal crest and si noatrial node followed by implantation of a pacemaker was performed in the AAI mode. Closed operations involved both transvenous electrodest ruction of the arrhythmogenic areas (5 patients) and destruction of th e His bundle with the development of complete transverse block and imp lantation of the pacemaker in the VVI mode. The best results were atta ined in young persons with Type I idiopathic atrial flutter where area s of fragmented and low-amplitude activity could be accurately specifi ed.