[Disorders of cardiac rhythm and conduction after radical correction of tetralogy of Fallot].

The work is based on the results of examination of 78 patients conducted before, in the immediate, and in the late-term periods after the operation (6.5 +/- 5.0 years on the average). Holter's monitoring and bicycle ergometry conducted before the operation revealed rhythm disorders in 55% of patients: complete block of the right limb of the bundle of His in 30, I-III degree atrioventricular block in 9%, supraventricular arrhythmias in 2.5%, ventricular arrhythmias in 5%, and combined arrhythmias in 7.5% of patients. Complete block of the right limb of the bundle of His was discovered in all patients in the late-term postoperative periods, and other types of rhythm disorders were found in 62% of patients: I degree atrioventricular block in 2.5%, bifascicular block in 2.5%, ++tri-fascicular block in 1%, ventricular arrhythmias in 26%, and combined arrhythmias in 30% of patients. The results of the examination showed that: (1) the presence of stable block of the right limb of the bundle of His, bifascicular block, as well as ventricular arrhythmia of I-II gradation after Laun-Wolf does not lead to decrease of myocardial working capacity and contractile function. In contrast, III-IV gradient ventricular arrhythmia is attended by significant diminution of myocardial contractility; (2) the incidence of ventricular arrhythmias grows with increase of the patients' age at the time of the operation and intensification of the degree of initial arterial hypoxemia and the anatomical severity of the anomaly; (3) correction of the anomaly contributes to the disappearance of the preoperative arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)