摘要
Objectives: To evaluate changes in plasma volume(Δ PV)during exercise in patients with single ventricular physiology with cyanosis; post-Fontan patients; and in patients after right ventricular outflow tract reconstruction(RVOTR). Background: Compensatory mechanisms which regulate body fluid volumes operate in heart failure patients to maintain blood pressure. A better understanding of this pathophysiological process, especially during exercise, should help manage and follow such patients. Methods: Twenty-six CHD patients(14± 4 years), including 5 cyanotic patients, 12 after the Fontan operation, 9 after RVOTR, and 13 controls(14± 5 years), performed a treadmill exercise test. Δ PV from rest to peak was calculated and compared with changes in cardiovascular responses,plasma total protein(TP), norepinephrine(NE), osmolality(Osm), and blood lactate concentration(La). Results:Δ PV was smaller in CHD patients than in controls(Cyanotic:-5.9% , Fontan:-10.0% , RVOTR: -11.4% , Controls:-14.5% , p< 0.001). In all subjects, peak heart rate, systolic blood pressure and oxygen uptake correlated inversely with Δ PV(p< 0.05 to 0.005). Δ PV correlated inversely with changes in TP, NE, and La(p< 0.005 for all), but not with the change in Osm. In CHD patients, the Δ PV correlated only with the NE increase(p< 0.01). Conclusions: Δ PV is smaller in CHD patients than in controls, especially in cyanotic patients. The smaller increases in cardiovascular responses during exercise and La are associated with the small Δ PV. These mechanisms may help to maintain cardiac output and increased sympathetic nervous activity may be beneficial to ensure sufficient perfusion pressure against Δ PV during exercise.
Objectives： To evaluate changes in plasma volume（APV） during exercise in patients with single ventricular physiology with cyanosis; post-Fontan patients; and in patients after right ventricular outflow tract reconstruction（RVOTR）. Background： Compensatory body fluid volumes operate maintain blood pressure. A mechanisms which regulate in heart failure patients to better understanding of this pathophysiological process, especially during exercise, should help manage and follow such patients. Methods： Twenty-six CHD patients（14±4 years）, including 5 cyanotic patients, 12 after the Fontan operation, 9 after RVOTR, and 13 controls（14±5 years）, performed a treadmill exercise test. APV from rest to peak was calculated and compared with changes in cardiovascular responses, plasma total protein（TP）, norepinephrine（NE）, osmolality（Osm）, and blood lactate concentration（La） . Results： APV was smaller in CHD patients than in controls （Cyanotic： - 5.9% , - 11.4%, Controls： - Fontan： - 10. 0% . RVOTR 14.5%, p 〈0.001）. In all subjects, peak heart rate, systolic blood pressure and oxygen uptake correlated inversely with APV（p 〈 0.05 to 0. 005）. APV correlated inversely with changes in TP, NE, and La （p 〈 0. 005 for all）, but not with the change in Osm. In CHD patients, the APV correlated only with the NE increase（p 〈 0. 01） . Conclusions： APV is smaller in CHD patients than in controls, especially in cyanotic patients. The smaller increases in cardiovascular responses during exercise and La are associated with the small APV. These mechanisms may help to maintain cardiac output and increased sympathetic nervous activity may be beneficial to ensure sufficient perfusion pressure against APV during exercise.
