Kenya Kusunose1, Hirotsugu Yamada2, Susumu Nishio3, Ayumi Ishii4, Yukina Hirata3, Hiromitsu Seno5, Yoshihito Saijo5, Takayuki Ise5, Koji Yamaguchi5, Shusuke Yagi5, Takeshi Soeki5, Tetsuzo Wakatsuki5, Masataka Sata5. 1. Department of Cardiovascular Medicine, Tokushima University Hospital, Tokushima, Japan. Electronic address: kusunosek@tokushima-u.ac.jp. 2. Department of Cardiovascular Medicine, Tokushima University Hospital, Tokushima, Japan. Electronic address: yamadah@tokushima-u.ac.jp. 3. Ultrasound Examination Center, Tokushima University Hospital, Tokushima, Japan. 4. Department of Nursing, Tokushima University Hospital, Tokushima, Japan. 5. Department of Cardiovascular Medicine, Tokushima University Hospital, Tokushima, Japan.
Abstract
OBJECTIVES: The aim of this study was to assess the relationship between right ventricular (RV) function during pre-load augmentation and exercise tolerance. BACKGROUND: Peak oxygen uptake (VO2) is a strong predictor of mortality in chronic heart failure. Cardiac function during pre-load augmentation is an important part of the phenomenon in the evaluation of exercise capacity. METHODS: We prospectively performed echocardiographic studies in 68 chronic heart failure patients with cardiopulmonary exercise testing (mean age 60 ± 12 years; 69% male). After resting evaluations, echocardiographic parameters were repeated during leg positive pressure (LPP). Exercise capacity was assessed by peak VO2 in all patients (left ventricular ejection fraction: 43 ± 15%). RESULTS: Patients with severely reduced exercise capacity (peak VO2 <14 ml/kg/min) had significantly lower stroke volume index, left ventricular global longitudinal strain and RV strain and higher filling pressure (E/e' and pulmonary arterial systolic pressure) than the remainder. Stroke volume index (β = 0.49), global longitudinal strain (β = -0.61), E/e' (β = -0.32), pulmonary arterial systolic pressure (β = -0.57), and RV strain (β = -0.66) during LPP were independently correlated to peak VO2 (all p < 0.01). RV strain during LPP was the most powerful predictor in identifying patients with severely reduced exercise capacity (cut off value: -17%; sensitivity: 81%; specificity: 88%; areas under the curve: 0.88; p < 0.001) compared with other variables including resting parameters. CONCLUSIONS: RV strain during pre-load augmentation correlated independently to peak VO2 and was a powerful predictor in identifying patients with severely reduced exercise capacity.
OBJECTIVES: The aim of this study was to assess the relationship between right ventricular (RV) function during pre-load augmentation and exercise tolerance. BACKGROUND: Peak oxygen uptake (VO2) is a strong predictor of mortality in chronic heart failure. Cardiac function during pre-load augmentation is an important part of the phenomenon in the evaluation of exercise capacity. METHODS: We prospectively performed echocardiographic studies in 68 chronic heart failurepatients with cardiopulmonary exercise testing (mean age 60 ± 12 years; 69% male). After resting evaluations, echocardiographic parameters were repeated during leg positive pressure (LPP). Exercise capacity was assessed by peak VO2 in all patients (left ventricular ejection fraction: 43 ± 15%). RESULTS:Patients with severely reduced exercise capacity (peak VO2 <14 ml/kg/min) had significantly lower stroke volume index, left ventricular global longitudinal strain and RV strain and higher filling pressure (E/e' and pulmonary arterial systolic pressure) than the remainder. Stroke volume index (β = 0.49), global longitudinal strain (β = -0.61), E/e' (β = -0.32), pulmonary arterial systolic pressure (β = -0.57), and RV strain (β = -0.66) during LPP were independently correlated to peak VO2 (all p < 0.01). RV strain during LPP was the most powerful predictor in identifying patients with severely reduced exercise capacity (cut off value: -17%; sensitivity: 81%; specificity: 88%; areas under the curve: 0.88; p < 0.001) compared with other variables including resting parameters. CONCLUSIONS: RV strain during pre-load augmentation correlated independently to peak VO2 and was a powerful predictor in identifying patients with severely reduced exercise capacity.