Reproducibility of echocardiography in chronic congestive heart failure

The purpose of this study was to define the reproducibility of serial echocardiographic measurements of left ventricular size and function. Fourteen patients in stable condition after heart failure (Group I) had five weekly outpatient echocardiograms performed by a single technician with blinded interpretation. The average end-diastolic diameter (EDD) of all patients was 68 mm, with a mean standard deviation of 4 mm and a 95% confidence interval of 8 mm. The average end-systolic diameter (ESD) was 58 mm; the 95% confidence interval was 5.6%. A group of four patients with heart failure (Group II) had daily echocardiograms while undergoing continuous hemodynamic monitoring. Pulmonary capillary blood pressure and thermodilution cardiac outputs were stable throughout the 4-day study period. Daily morning echographic measurements were constant, with 95% confidence interval of the EDD being only 4 mm. The ESD and % delta D had 95% confidence intervals of 2 mm and 3.2%, respectively. The narrow range of measurements (narrow confidence intervals) demonstrates the excellent reproducibility of these echocardiographic parameters.