BACKGROUND: We hypothesized left ventricular (LV) dyssynchrony would affect postexercise accommodation of regional myocardial motion in patients with heart failure and a normal ejection fraction (HFNEF). METHODS AND RESULTS: Tissue-Doppler echocardiography was studied in 100 hypertensive patients with LV ejection fraction >50%. Among them, 70 HFNEF patients were classified into the systolic dyssynchrony (Dys: >65 ms difference of electromechanical delay between septal and lateral segments) (43 patients) and nondyssynchrony (Ndys: 27 patients) groups, and the other 30 patients were as the control (Ctrl). The systolic myocardial velocities (Sm) of 6-basal LV segments at baseline and after exercise were analyzed. When compared with the Ctrl group, the baseline lower mean Sm of 6 LV segments in the Ndys group could increase to a similar postexercise level as that in the Ctrl group, whereas that in the Dys group remained lower after exercise (7.8 ± 1.3 versus Ndys: 8.6 ± 1.5 and Ctrl: 8.9 ± 1.2 cm/s, P < .05, respectively). This is mainly due to a much higher percentage increase of lateral Sm after exercise in the Ndys group (Ndys: 49 versus Dys: 29%, P < .05). CONCLUSIONS: Dyssynchrony-related regional myocardial contractile abnormality after exercise in HFNEF patients suggested the detrimental impact of electromechanical uncoupling on HF symptoms.
BACKGROUND: We hypothesized left ventricular (LV) dyssynchrony would affect postexercise accommodation of regional myocardial motion in patients with heart failure and a normal ejection fraction (HFNEF). METHODS AND RESULTS: Tissue-Doppler echocardiography was studied in 100 hypertensivepatients with LV ejection fraction >50%. Among them, 70 HFNEF patients were classified into the systolic dyssynchrony (Dys: >65 ms difference of electromechanical delay between septal and lateral segments) (43 patients) and nondyssynchrony (Ndys: 27 patients) groups, and the other 30 patients were as the control (Ctrl). The systolic myocardial velocities (Sm) of 6-basal LV segments at baseline and after exercise were analyzed. When compared with the Ctrl group, the baseline lower mean Sm of 6 LV segments in the Ndys group could increase to a similar postexercise level as that in the Ctrl group, whereas that in the Dys group remained lower after exercise (7.8 ± 1.3 versus Ndys: 8.6 ± 1.5 and Ctrl: 8.9 ± 1.2 cm/s, P < .05, respectively). This is mainly due to a much higher percentage increase of lateral Sm after exercise in the Ndys group (Ndys: 49 versus Dys: 29%, P < .05). CONCLUSIONS: Dyssynchrony-related regional myocardial contractile abnormality after exercise in HFNEF patients suggested the detrimental impact of electromechanical uncoupling on HF symptoms.