HEMODYNAMIC PATTERNS AND DURATION OF POST-DYNAMIC EXERCISE HYPOTENSION IN HYPERTENSIVE HUMANS

We investigated: 1) the mechanism of the hypotensive effect of a singl e bout of dynamic exercise in hypertensive subjects by measuring hemod ynamic parameters before and for 2 h after treadmill exercise, and 2) the duration of the effect using ambulatory blood pressure (BP) monito ring once the subjects left the test site. Ten minutes after exercise there was a significant decrease from baseline systolic pressure (SP; -14 +/- 3 mm Hg), mean arterial pressure (MAP; -7 +/- 2 mm Hg), total peripheral resistance (TPR; -3.7 +/- 1.2 units), calf vascular resista nce (CVR; -25.4 +/- 4.1 units), and an increase in HR (19 +/- 2 bpm). The changes in SP, DP, MAP, and HR were maintained during the 2 h of p ost-exercise monitoring; CVR remained decreased for 1 h; TPR returned to baseline within 20 min and then tended to be slightly elevated. CO was significantly decreased at 50, 60, and 120 min after exercise. We conclude that the early decline in BP after dynamic exercise in hypert ensive subjects follows a biphasic pattern: 1) an initial decrease in total and regional vascular resistance with maintained CO, 2) followed by increasing resistance and decreased CO. Pre-exercise hypertensive BP values returned during subsequent ambulatory monitoring.