Differences in cardiac chamber volumes during prone versus supine imaging

Abstract

Methods 11 subjects (27% females), age 54.9+17.3, 10 without clinical heart disease and 1 with coronary artery disease and normal ventricular function were imaged in supine and prone position using retrospectively gated SSFP cine imaging in contiguous short axis planes covering both right(RV) and left (LV) ventricles. Left and right ventricular end diastolic(EDV) and end systolic volumes(ESV), stroke volume(SV), cardiac output(CO) and ejection fraction (EF) were derived for both positions by a single highly experienced image analyst using Medis QMass MR software version 6.2.3 and compared using paired t tests. Heart rate (HR) and blood pressure (BP) were also compared. Results (Table 1) Both LV and RV EDV and SV were reduced in prone versus supine position with a small increase in heart rate and no change in EF or BP. Thus CO was also significantly reduced. LV ESV did not change significantly but RV ESV was reduced in prone position.