[Clinico-electrophysiologic relations in isolated complete atrioventricular block, congenital or idiopathic]

Congenital or idiopathic complete A-V block with no detectable heart disease may be complicated by near syncope, syncope or sudden death. The proposed predictive "risk factors" of these events have not proved sufficiently reliable so far. This study was undertaken in order to re-evaluate the correlation between symptoms and clinical and electrophysiological data with particular regard to the junctional recovery time in 10 patients (4 M; 6 F; mean age 24.4 +/- 9.6 at our first observation) with congenital or idiopathic complete A-V block. Patients were divided into 2 groups: group A (3 M; 3 F; mean age 27.8 +/- 10.6 at our first observation) with patients who complained of vertigo, near syncope or syncope before our study; group B (1 M; 3 F; mean age 19.2 +/- 4.1 at first observation) without cardiovascular symptoms before our study. In group A, Holter monitoring revealed periods of asystole longer than 3000 ms in 2, and ectopic ventricular arrhythmias mainly during effort in 2; ergometric stress test performed in 3 patients demonstrated ectopic ventricular arrhythmias in 2 (those who had ectopic ventricular arrhythmias at rest). In all patients the site of the block was suprahisian (demonstrated by electrophysiologic endocavitary study) with a normal H-V interval; mean junctional recovery time was 4.600 +/- 1.620 ms and corrected junctional recovery time was 3.088 +/- 1.500. Four patients had vertigo during the electrophysiologic endocavitary study. After Atropine 0.02 mg/Kg i.v. junctional recovery time and corrected junctional recovery time decreased respectively to 1052 +/- 238 and 166 +/- 38 ms (the measurement was made in 5 patients). In group B Holter monitoring revealed periods of asystole longer than 3000 ms in 1 case. All patients had ectopic ventricular arrhythmias, confirmed by the stress test. In this group too, the block was suprahisian (electrophysiologic endocavitary study) with normal H-V. Mean junctional recovery time was 5162 +/- 2408 ms; and corrected junctional recovery time 3687 +/- 2202. Two patients complained of dizziness during the electrophysiologic endocavitary study. After Atropine 0.02 mg/Kg i.v., junctional recovery time and corrected junctional recovery time decreased respectively to 1300 +/- 356 and 260 +/- 145 ms. Four group A and 1 group B patients received a permanent pacemaker and have remained asymptomatic since.(ABSTRACT TRUNCATED AT 400 WORDS)