Microvolt T-wave alternans (TWA) was measured in 200 patients to evaluate t
he influence of heart rate on TWA induced by atrial pacing. TWA onset heart
rate in patients with organic heart disease (OHD) and sustained ventricula
r tachyarrhythmias (VTs) was significantly lower than that in patients with
OHD without sustained VT or in patients without OHD or VT.