1. Twelve asymptomatic young men with ‘primary’ T-wave aberrations in the electrocardiogram (group T) and 13 matched controls were subjected to a mental stress test, isometric exercise and a cold pressor test.
2. Plasma catecholamines and haemodynamics were studied.
3. Group T had signs of increased sympathetic activity at rest and enhanced sympatho-adrenal reactivity during stress.
4. Systolic blood pressure was consistently elevated in group T.
5. The T-wave aberrations may be explained by the increased sympathetic activity.
6. Several similarities exist between group T and borderline hypertensive subjects.