Circulating catecholamines and systolic time intervals in normotensive and hypertensive patients with and without left ventricular hypertrophy

Circulating catecholamine (CA) levels were measured in normotensive and hypertensive patients with or without left ventricular hypertrophy (LVH) and were related with systolic time intervals, heart rate, and blood pressure. The pre-ejection period (PEP) and the ratio PEP LVET were correlated with circulating CA in normotensive and hypertensive patients. For a given circulating CA level, the PEP was higher in hypertensive patients with LVH than in those without LVH. This is probably secondary to a diminished myocardial contractility in these patients. Heart rate was related with circulating CA in hypertensive patients without LVH. When hypertensive patients without LVH were divided into normoadrenergic (circulating CA levels within normotensive range) and hyperadrenergic (circulating CA above normal range) groups, the hyperadrenergic group was found to have significantly higher heart rate than normotensive patients while the heart rate of the normoadrenergic group was similar to that of the normotensive group. PEP and PEP LVET were significantly elevated in the normoadrenergic group when compared with normotensive subjects but were not different in the hyperadrenergic group. These differences in chronotropic and inotropic myocardial activity between these two groups of hypertensive patients with normal and high levels of circulating CA suggest that they are separate entities.