Περίληψη:
Acute myocardial ischemia decreases conduction velocity through the
ischemic myocardium and may produce QRS prolongation on the surface
electrocardiogram. To investigate the effect of exercise-induced
myocardial ischemia on the QRS duration, 124 patients who underwent
diagnostic cardiac catheterization and exercise thallium-201
scintigraphy were studied. Seventeen patients had normal coronary
arteries and 107 had coronary artery disease. QRS duration decreased
with exercise in patients with normal coronary arteries (-3.7 ms,
confidence interval -7.7 to 0.3) but increased in patients with coronary
artery disease; exercise-induced QRS prolongation was directly related
to the number of vessel disease (1.2 ms in patients with one-vessel
disease; 8.7 ms in patients with two-vessel disease, and 10.5 ms in
patients with three-vessel disease, p < 0.001). Likewise,
exercise-induced QRS duration decreased in patients without
exercise-induced reversible perfusion defects (-1.3 ms, confidence
limits -2.8 to 0.2) but increased in patients with exercise-induced
perfusion defects (9.7 ms in patients with one perfusion defect; 13.6 ms
in patients with two perfusion defects, and 16.3 ms in patients with
three perfusion defects, p < 0.001). Exercise-induced QRS prolongation
was best related to the number of exercise-induced perfusion defects
than to the number of vessel disease, p < 0.001. In conclusion,
exercise-induced QRS prolongation in patients with coronary artery
disease was directly related to the number of vessel disease and to
exercise-induced perfusion defects. This QRS prolongation was better
related to the number of reversible perfusion defects than to the number
of vessel disease. Thus, exercise-induced QRS prolongation in patients
with coronary artery disease may be a marker of exercise-induced
myocardial ischemia.
Συγγραφείς:
MICHAELIDES, A
RYAN, JM
VANFOSSEN, D
POZDERAC, R
BACON,
JP
BOUDOULAS, H
