Essential hypertension--implications for pathogenesis from repeated haemodynamic investigations in young men with elevated blood pressure.

Repeated invasive haemodynamic studies were performed in young men (18-21 years) with elevated blood pressures and age and sex-matched normotensive controls before military service and five years later as a follow-up study. Patients with high blood pressure initially showed increased cardiac output and increased vascular resistance during maximal vasodilatation. The latter observation suggests arteriolar wall hypertrophy but was restricted to the subgroup of patients with low/normal cardiac output (normokinetic subgroup). In the follow-up study the cardiac output in patients with high blood pressure was no longer increased in comparison with controls and this normalization was restricted to patients previously showing the highest cardiac output (hyperkinetic subgroup). Contrary to the hypothesis this subgroup of patients had not developed significant signs of arteriolar wall hypertrophy although a tendency was present.