Early onset and significance of imcomplete left posterior hemiblock in Nigerians

Following detailed clinical and electrocardiographic analysis, twenty-five patients with incomplete left posterior hemiblock without associated complete right or left bundle branch block are presented. First-degree atrioventricular block was relatively common in these patients and associated incomplete right or left bundle branch block was also present in a few. Hypertension was the commonest underlying cardiovascular disease but two of them, without any clinically overt cardiovascular disease, presented with a history of episodic dizziness or syncopal attacks. With the present knowledge of the anatomy and histopathology of intraventricular conduction system, the relevance of tendency for Africans to form excessive fibrous tissue has been emphasized. Considering the unexpectedly low average age of these patients, suggestions have been made with a view to reducing the rate of progression of such atrioventricular conduction defects to the need for implanted cardiac pacemakers.