Dynamics of the pulmonary circulation in systemic hypertension

Pulmonary and systemic hemodynamics in 28 mild to moderate hypertensive patients (group II) with left ventricular (LV) hypertrophy (ECG and echo criteria) and 22 severe hypertensive patients with LV hypertrophy (group III) were compared with 20 patients with mild-to-moderate hypertension in WHO stage I (group I). Mean right atrial pressure was equivalent in groups II and III and significantly higher in the last group than in group I. An increased pulmonary arterial resistance (PAR) in group II and, to a large extent, in group III accounted for the elevation of diastolic and mean pulmonary arterial pressure in both groups in comparison with group I. Cardiac index (CI) was lower and systemic vascular resistance (SVR) higher in group III than in group I. Pulmonary capillary wedge pressure (PCWP) values were within the normal range and equivalent between groups II and III, and both significantly higher than in group I. PAR showed a positive relation with SVR (r = 0.30, P less than 0.01) and an inverse relation with CI (r = -0.561, P less than 0.001). Findings indicate that in systemic hypertension with LV hypertrophy there is an elevation of the right ventricular filling pressure and the pulmonary arterial pressure whose degree is even higher in severe hypertension. This increase is not necessarily a consequence of impairment of LV function as suggested by the normal range of PCWP values.