Hyperdynamic circulation distinguishes predominantly diastolic hypertension from predominantly systolic hypertension.

Abstract

Elevated blood pressure is traditionally classified into systolic-diastolic hypertension, isolated systolic hypertension, and isolated diastolic hypertension. In this cross-sectional study, participants not using antihypertensive medications (n = 654) were divided into normotensive subjects (n = 421), and predominantly systolic (n = 130) versus predominantly diastolic hypertension (n = 103) based on the percentage elevation of aortic blood pressure above 125 mmHg systolic or 85 mmHg diastolic. Non-invasive hemodynamics were recorded using radial applanation tonometry and whole-body impedance cardiography during passive head-up tilt. Mean aortic blood pressures in the groups were 108/73, 141/89, and 131/94 mmHg, respectively. Mean age and BMI (43.6, 47.3 and 52.6 years; 25.9, 28.7 and 28.7 kg/m², respectively) were lower in the normotensive than in hypertensive participants (p < 0.05). Predominantly systolic hypertension was characterized by higher forward wave amplitude, central pulse pressure, and systemic vascular resistance (p < 0.003 for all) than predominantly diastolic hypertension. Predominantly diastolic hypertension was characterized by higher heart rate and cardiac index (p < 0.004 for both), but lower stroke volume (p < 0.002), than predominantly systolic hypertension. Both hypertensive groups had increased systemic vascular resistance, but highest values were observed in predominantly systolic hypertension (p < 0.001). Pulse wave velocity was equally elevated by ~1 m/s in both hypertensive groups (p < 0.001). In response to head-up tilt, the increase in systemic vascular resistance, and the decrease in cardiac output, were more pronounced in predominantly systolic versus diastolic hypertension. To conclude, predominantly diastolic hypertension featured hyperdynamic circulation, while increased pulse pressure in predominantly systolic hypertension was related to higher stroke volume and systemic vascular resistance than in predominantly diastolic hypertension.