Reversible T-wave abnormality in severe acute asthma: an electrocardiographic sign of severity

Reversible electrocardiographic (ECG) abnormalities are well recognized in severe acute asthma. Inferior lead T-wave abnormalities have only rarely been reported, and their frequency and significance have not been well documented. We studied 70 consecutive patients with severe acute asthma on admission to hospital and during recovery, in order to examine the frequency and natural history of such changes and to document their relationship to the severity of the attack. Twenty-two patients (34%) had inferior lead T-wave inversion on ECGs performed within 1 h of admission (group 1), whereas the rest did not (group 2). Apart from sinus tachycardia this was the most common ECG abnormality. Patients with inferior T-wave inversion were found to have more severe asthma in terms of degree of pulsus paradoxus, peak expiratory flow rate, forced expiratory volume in 1 s and arterial blood oxygen tension. Ten group 1 and ten group 2 patients underwent two-dimensional echocardiography during the acute phase of their illness and during recovery. Six (60%) group 1 patients showed echocardiographic evidence of right ventricular pressure overload compared with only one (10%) patient in group 2 (P less than 0.02). Following recovery, voluntary hyperventilation and exercise testing in ten group 1 patients failed to reproduce the ECG changes seen on admission. Reversible inferior lead T-wave abnormalities may occur in the severe acute asthma and appear to be related to the severity of the attack.