title: Electrocardiographic aspects of acute left anterior hemiblock induced by exercise.
abstract: The intraventricular conduction time was measured during rest, exercise, and recovery in five patients who developed acute left anterior hemiblock during exercise-induced myocardial ischemia. The A QRS shifted from 58 +/- 17 degrees at rest to -66 +/- 11 degrees during exercise (p less than 0.001). The intraventricular conduction time at rest was 86 +/- 4 ms and increased to only 90 +/- 4 ms during left anterior hemiblock. Our observations suggest that the intraventricular conduction time is not always prolonged during left anterior hemiblock, particularly if this conduction abnormality is acute.
mesh_terms: D000328:Adult; D003327:Coronary Disease / Q000175:diagnosis; D005080:Exercise Test; D006327:Heart Block / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged