[Changes in local blood flow and energy metabolism in patients with hypertension with different degrees of tolerance of isometric load (hand grip)].

The onset of muscular fatigue and the patterns of exercise and postcontraction hyperemia, oxygen consumption and lactate release were examined in 50 male patients with essential hypertension, doing hand grip with an effort amounting to 5% of their maximum unrestricted potential. Subgroups of patients with normal and rapid onset of forearm muscular fatigue were identified. Unlike normal subjects and hypertensive patients with normal onset of muscular fatigue, patients with increased muscular fatigability demonstrated a progressive increase rather than stabilization of blood flow rate, oxygen consumption and lactate release which continued until the patient gave up exercise. Different patterns of blood supply, energy metabolism and muscular fatigability are believed to result from changed vascular resistance.