Objective-To determine whether the reactive hyperaemic response of the lower limb increases with improved exercise capacity after acute supplementation with L-arginine, the precursor of nitric oxide, in patients with chronic heart failure. Methods-19 patients with chronic heart failure were enrolled in the study. Rest calf blood flow and femoral occlusion induced calf blood flow changes were measured by venous occlusion plethysmography before and after intravenous infusion of 10% L-arginine solution (5 ml/kg for 30 minutes) or placebo. Postexercise calf blood flow was also measured after the experimental infusion. During both postinfusion periods, several exercise capacity indices were determined by a symptom limited cardiopulmonary exercise test using a bicycle ergometer. Results-Baseline calf blood flow, systemic blood pressure, and heart rate showed no significant changes in either of the two experimental conditions. However, the occlusion induced blood flow response was significantly enhanced by L-arginine infusion (mean (SEM) peak flow, 19.6 (1.5) v 28.9 (3.1) ml/min/dl calf tissue; p < 0.01), but not by placebo (peak flow, 19.1 (1.4) v 20.9 (1.8) ml/min/dl calf tissue; NS). Calf blood flow response after exercise was also higher after L-arginine infusion than after placebo (peak flow, 4.8 (0.4) v 6.0 (0.8) ml/min/dl calf tissue; p < 0.05). L-arginine infusion had no significant eVect compared with placebo on exercise capacity indices such as peak oxygen uptake (17.1 (1.0) v 15.8 (1.1) ml/min/kg; NS), anaerobic threshold (10.5 (0.6) v 10.4 (0.7) ml/min/kg; NS), and exercise time (296 (23) v 283 (22) s; NS). Conclusions-Acute supplementation with the nitric oxide precursor L-arginine increased lower limb reactive hyperaemia but did not lead to any significant improvement in exercise capacity in patients with chronic heart failure. (Heart 1999;81:512-517)
Spontaneous simultaneous multivessel coronary artery spasm in patients with acute myocardial infarction (AMI) is uncommon. A 79-year-old Japanese man was transferred to this hospital because of severe prolonged chest pain and faintness. Left coronary angiography revealed total occlusion of the left anterior descending and the left circumflex coronary arteries. Moreover, right coronary angiography revealed 99% stenosis of the right coronary artery. After intracoronary administration of nicorandil, left coronary artery and right coronary artery angiography revealed no organic stenosis or thrombus. This is the first report in which simultaneous 3-vessel spasm was documented by emergency angiography in AMI.
Aims Reduced skeletal muscle blood flow during exercise is an important factor contributing to exercise intolerance in patients with chronic heart failure. Reactive hyperaemic blood flow is the maximum flow response necessary to protect tissue against ischaemia and hypoperfusion. We examined the vasodilatory response of the lower limb to ascertain whether response was increased with the improvement in exercise capacity observed after intracardiac surgery in patients with chronic heart failure due to valvular heart disease.
Methods and ResultsCalf blood flow in 23 patients was measured by venous occlusion plethysmography at rest and after a 5 min period of femoral occlusion. Immediately after this evaluation, peak oxygen uptake and anaerobic threshold were assessed by a symptom-limited cardiopulmonary exercise test using a bicycle ergometer. Both baseline calf blood flow and peak calf blood flow during reactive hyperaemia were significantly increased after surgery (baseline calf blood flow; from 2-6 ± 0-2 to 3-8 ± 0-4 ml. min " ' per 100 ml calf volume, /><005: peak calf blood flow; from 175 ± 1-3 to 25-4 ± 2-6 ml . min" ' per 100ml calf volume, P<001). There was a significant correlation between changes in peak calf blood flow and improvement in exercise capacity (peak oxygen uptake; r=0-42, P<005; anaerobic threshold; r=0-68, P<0-0010).
ConclusionThese results indicate that exercise tolerance is improved with increased lower limb vasodilatory capacity after recovery from chronic heart failure.
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