New data on etiology of heart conduction disturbances

Aim. To make a clinicogenealogical analysis of different types of heart con duction disturbances in families of Krasnoyarsk city. Materials and methods. 104 probands with ECG-verified idiopathic forms of a trioventricular and intraventricular blocks of different severity and 331 t heir close relatives (kinship degree I and II) were examined using standard clinical investigations, ECG, echocardioscopy, electrophysical investigati ons in some cases and coronarography. Results. All the observed 104 families were divided into 3 groups according to the type of heart conduction in proband. Group 1 consisted of 24 proban ds with atrioventricular block and 80 their relatives. The sick relatives h ad for the most part atrioventricular blocks (31.2%). 26 probands of group 2 had complete right bundle branch blocks. Of their 81 relatives, the sick ones had primarily conduction disturbances in right bundle branch (incomple te block - 44.7%, a complete block - 5.2%). Group 3 consisted of 54 proband s wit left bundle branch block and 170 relatives. The left bundle branch bl ock was present in 27.4% of the relatives. Conclusion. A definite family aggregation of heart conduction disturbances was found. This proves genetic determination of this pathology.