Exercise-induced muscle vasodilatation and treadmill exercise test responses in individuals without overt heart disease.

BACKGROUND: The beneficial effects of exercise on cardiovascular health may be related to the improvement in several physiologic pathways, including peripheral vascular function. The aim of this study was to evaluate the relationship between cardiovascular responses during the treadmill exercise test and exercise-induced muscle vasodilatation in individuals without overt heart disease. METHODS: The study included 796 asymptomatic subjects (431 females and 365 males) without overt heart disease. We evaluated the heart rate (chronotropic reserve and heart rate recovery), blood pressure (maximum systolic and diastolic blood pressure as well as systolic blood pressure recovery) and exercise capacity during symptom-limited treadmill exercise testing. Exercise-induced muscle vasodilatation was studied with venous occlusion plethysmography and estimated by forearm blood flow and vascular conductance responses during a 3-min handgrip maneuver. RESULTS: Forearm blood flow increase during the handgrip exercise was positively associated with heart rate recovery during treadmill exercise testing (p < 0.001). Forearm vascular conductance increase during the handgrip exercise was inversely associated with exercise diastolic blood pressure during exercise treadmill testing (p = 0.038). No significant association was found between exercise capacity and exercise-induced muscle vasodilation. CONCLUSION: In a sample of individuals without overt heart disease, exercise-induced muscle vasodilatation was associated with heart rate and blood pressure responses during treadmill exercise testing, but was not associated with exercise capacity. These findings suggest that favorable hemodynamic and chronotropic responses are associated with better vasodilator capacity, but exercise capacity does not predict muscle vasodilatation.

Angiotensin-converting enzyme gene deletion polymorphism modulation of onset of symptoms and survival rate of patients with heart failure.

BACKGROUND: Angiotensin-converting enzyme is involved in the pathophysiology of heart failure. We hypothesized that clinical characteristics as well as survival rate in patients with heart failure of different etiologies may be modulated by functional variants DD, ID and II of the angiotensin-converting enzyme gene. METHODS: We studied 333 patients with heart failure, aged 43.3 +/- 10.5 years, 262 (78.7%) men and 71 (21.3%) women. Heart failure was ascribed to idiopathic dilated cardiomyopathy in 125 patients. Heart failure was caused by ischemic heart disease in 63 patients, Chagas' disease in 58, hypertensive heart disease in 41, alcoholic cardiomyopathy in 24, and was due to other etiologies in 22 patients. Statistical analysis was performed with the chi(2) test, Student's t-test, analysis of variance, Kaplan-Meier and Cox proportional hazards methods. RESULTS: The DD genotype was associated with increased systolic left ventricular diameter (p = 0.031). Earlier onset of symptoms was observed in patients with alcoholic cardiomyopathy and DD genotype (p = 0.033, codominant D) and in patients with hypertensive cardiomyopathy and DD genotype (p = 0.048, codominant D; p = 0.024, recessive D). Mortality was higher in patients older than 50 years with DD genotype (p = 0.007, codominant D; p = 0.002, recessive D). Variables independently associated with higher mortality in patients older than 50 years were age, diabetes mellitus, Chagas' disease etiology and DD genotype. CONCLUSIONS: These results add evidence for an association of the DD genotype of the angiotensin-converting enzyme gene with earlier onset of symptoms and decreased survival rate of selected patients with heart failure.