Electrocardiographic aspects of acute left anterior hemiblock induced by exercise.
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.
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