Relation of changes over time in ventricular size and function to those in exercise capacity in patients with chronic heart failure

Abstract

Background We studied the direction and magnitude of changes in left ventricular (LV) cavity size and mass over time and whether these changes were related to those in exercise performance in patients with chronic heart failure (CHF). Methods and Results The study group was composed of 59 patients (55 men aged 58 ± 10 years) with CHF and LV end-diastolic diameter (EDD) >55 mm. All underwent echocardiography and a treadmill cardiopulmonary exercise test within a 4-week interval (baseline) and again after a period of ≥4 months (median of 14 months). At baseline, the group as a whole had moderate to severe LV dysfunction with an EDD of 70 ± 9 mm, end-systolic diameter (ESD) of 60 ± 11 mm, and LV mass of 500 ± 200 g. The mean peak oxygen consumption (VO 2, 18 ± 6 mL/kg per minute) was unrelated to LV cavity size or mass. EDD increased in 37 (63%) of the patients and fell in 22 (37%) patients from the initial to the second test. The absolute magnitude of changes over time averaged 7 mm for EDD, 125 g for mass, and 6 mL/kg per minute for peak VO 2. Changes in LV size and mass per year were significantly related to those in peak VO 2 ( r = −0.49 for EDD, r = −0.56 for ESD, and r = −0.44 for LV mass, respectively, all P < .001) and ventilatory response to exercise ( r = 0.60, r = 0.58, and r = 0.72 for EDD, ESD, and LV mass; respectively, all P < .001). Conclusions Changes over time in objective measures of LV dimensions and mass, in patients with CHF are significantly related to those in exercise capacity and respiratory efficiency.