Severe congestive heart failure (NYHA III) was associated with higher resting lactate compared to controls (1.18 vs 0.65 mmol/l, P=0.002) and greater metabolic abnormalities during exercise.
Cross-Sectional (n=53)
No
Are there abnormalities in skeletal muscle metabolism at rest and during exercise in patients with congestive heart failure compared to controls?
Patients with congestive heart failure exhibit abnormal skeletal muscle metabolism at rest, with exercise-induced metabolic abnormalities correlating with symptom severity.
OBJECTIVE: To investigate abnormalities of skeletal muscle metabolism in patients with congestive heart failure. SETTING: A university teaching hospital. METHODS: 43 patients (22 New York Heart Association (NYHA) grade II, 21 grade III) and 10 controls were studied. A forearm model of muscle metabolism was used, with a cannula inserted retrogradely into an antecubital vein of the dominant forearm. Maximum voluntary contraction (MVC) was measured using handgrip dynamometry. Subjects performed handgrip exercise, 5 s contraction followed by 5 s rest for 5 min at 25%, 50%, and 75% of MVC or until exhaustion. Blood was taken at rest and 0 and 2 min after exercise for measurement of lactate and ammonia. After 30 min the procedure was repeated with fixed workloads of 7 kg, 14 kg, and 21 kg. RESULTS: MVC (kg, mean (SEM)) was lower in patients than in controls (control 42.45 (2.3); NYHA II 34.13 (1.3), P = 0.003; NYHA III 33.13 (1.94), P = 0.008). Resting lactate (mmol/l) was higher in patients than controls (control 0.65 (0.06); NYHA II 0.84 (0.08), P = 0.13; NYHA III 1.18 (0.1), P = 0.002). Resting ammonia (mumol/l) was higher in NYHA III (65.7 (6.0)) than in NYHA II (48.0 (3.7), P = 0.016); no difference was found between controls (48.0 (7.1)) and patients. The overall lactate and ammonia response to exercise was greater in NYHA III than in NYHA II and controls (P < 0.05). At volitional exhaustion, peak lactate (mmol/l: NYHA III 3.31 (0.26); NYHA II 2.56 (0.16); controls 2.71 (0.22); P = 0.022 NYHA III v NYHA II) and ammonia (mumol/l: NYHA III) 126.4 (8.97); NYHA II 92.9 (7.23); controls 109 (16.3); P = 0.006 NYHA III v NYHA II) were higher in severe congestive heart failure. CONCLUSIONS: Skeletal muscle metabolism is abnormal at rest in congestive heart failure. During exercise, the degree of metabolic abnormality is related to the symptomatic status of the patient.
Andrews et al. (1997) conducted a cross-sectional in Congestive heart failure (n=53). Handgrip exercise vs. Healthy controls was evaluated on Skeletal muscle metabolism (lactate and ammonia) at rest and during exercise. Severe congestive heart failure (NYHA III) was associated with higher resting lactate compared to controls (1.18 vs 0.65 mmol/l, P=0.002) and greater metabolic abnormalities during exercise.