An association between high blood pressure and the coronary-prone (or type A) behaviour pattern, established as risk factors for myocardial infarction and sudden death, has been postulated on the basis of similar psychophysiological mechanisms involving the sympathetic nervous system. Psychodynamic personality profiles and type A behaviour assessment have therefore been related to biochemical markers of sympathetic overactivity, but type A behaviour scores were generally found to be low in hypertensive subjects - and lowest in those with high plasma noradrenaline. However, projective assessment of reactions to frustration during everyday stress indicates that hypertensive patients with high plasma renin activity as well as high noradrenaline have less externalized but more internalized aggression, and are submissive yet have a stronger need to resolve conflicts immediately. These incompatible tendencies result in chronic frustration. A similar high degree of suppressed anger is shared by patients at risk for coronary heart disease, and high renin patients have a higher incidence of critical cardiac events. This suggests the possibility of a 'hypertensive coronary-prone personality'. Because of their excellent antihypertensive response to chronic beta-blocker therapy, it is conceivable that high renin patients benefit most from the cardioprotective potential of beta-blocker-based antihypertensive therapy.