Adjustable pulmonary artery banding for 8 weeks in young lambs decreased cardiac output from 2.6 to 1.6 l/min (P<0.05) despite compensatory increased right ventricular global contractile performance.
Does adjustable pulmonary artery banding affect biventricular function in young lambs?
Chronic RV pressure overload in young lambs leads to diminished pump function and reduced inotropic reserve despite compensatory increases in baseline RV contractile performance.
Absolute Event Rate: 1.6% vs 2.6%
p-value: p=<0.05
In various clinical situations of congenital heart disease, the right ventricle (RV) is subject to a chronic systemic pressure overload which affects biventricular function and may progress to the development of RV failure. Young lambs (2–3 wk old) underwent adjustable pulmonary artery banding (PAB) at systemic (aortic) level for 8 wk. Biventricular function was determined by using load-independent indexes of global ventricular contractile performance by the end-systolic pressure-volume relationship (ESPVR) using the conductance catheter at baseline and during dobutamine infusion. PAB resulted in a significant fivefold increase in RV end-systolic pressure (12–64 mmHg) and a doubling of the RV-to-left ventricular (LV) wall thickness ratio ( P < 0.01). RV global contractile performance increased significantly, as indicated by an increased slope of the ESPVR. Compared with age-matched control lambs, cardiac output decreased from 2.6 to 1.6 l/min ( P < 0.05) whereas heart rates were equal. In contrast with RV volume, LV volume decreased significantly after PAB ( P < 0.01), whereas the LV-ESPVR slope was unchanged. In the PAB group, the RV, but not the LV, showed a reduced response to dobutamine. We concluded that chronic RV pressure overload for 8 wk results in diminished pump function despite compensatory increased RV global contractile performance.
Leeuwenburgh et al. (Sat,) conducted a other in Chronic systemic right ventricular pressure overload. Pulmonary artery banding (PAB) vs. Age-matched control lambs was evaluated on Cardiac output (l/min) (p=<0.05). Adjustable pulmonary artery banding for 8 weeks in young lambs decreased cardiac output from 2.6 to 1.6 l/min (P<0.05) despite compensatory increased right ventricular global contractile performance.