Myocardial contractile inefficiency and dyssynchrony in heart failure with preserved ejection fraction and narrow QRS complex.

BACKGROUND Using speckle-tracking imaging (STI), the aims of this study were to assess dyssynchrony and quantify the myocardial energy wasted by contractility in delayed segments by determining the longitudinal strain delay index (LSDi) in patients with heart failure with preserved ejection fraction (HFpEF). METHOD Thirty-eight patients with HFpEF and 33 matched controls were recruited. All subjects underwent clinical examinations, 12-lead electrocardiography, pulmonary function tests, echocardiography, and metabolic exercise tests. LSDi was determined, the magnitude of which is a measure of the amount of wasted energy. Global and segmental systolic and diastolic dyssynchrony was assessed by STI. RESULTS LSDi was significantly higher in patients with HFpEF than controls (-14.36 +/- 8.24% vs -10.73 +/- 5.62%, P <.05). Patients with HFpEF exhibited left ventricular (LV) systolic and diastolic dyssynchrony, with the LV anterior wall displaying the most delayed motion. CONCLUSION Patients with HFpEF exhibited increased myocardial contractile inefficiency. They also exhibited LV systolic and diastolic dyssynchrony, with the LV anterior wall displaying the most delayed motion.