2.4 Echocardiography
All echocardiographic procedures were performed using an
echocardiography platform equipped with a 2.5 MHz phased-array
transducer (Vivid 3, GE Healthcare, Piscataway, NJ). Per heart failure
clinic protocol, all examinations were performed by the members of
advanced heart failure team that are competent in echocardiographic
procedures. Stored images and 3-beat loops that were acquired from
parasternal long-axis, parasternal short-axis and apical views were
analyzed to repeat all measurements and calculations. Right ventricular
PDI was calculated using the following equation:
Eq 1. PASP / RVMD2
where RVMD is right ventricular minor diameter as measured immediately
above the tricuspid valve at end-diastole and PASP is the systolic
pulmonary artery pressure (Figure 1). Echocardiographic PASP was
calculated according to relevant guidelines (7). Right ventricular
contraction pressure index was calculated as defined before (8). For the
purposes of the present study, images were used from the
echocardiographic examination that immediately preceded left ventricular
assist device implantation, and this is done two days before planned
implantation date. None of the patients were on inotropes or vasoactive
drugs when echocardiographic examination was performed. All measurements
and calculations were performed according to relevant guidelines.