Two experimental models were studied to determine the hemodynamic consequences of
atrial volume reduction as observed after operative correction of transposition of
the great arteries. The volume of the left atrium (LA) was reduced either by inflation
of an intracavitary balloon (group A) or by surgical intervention (group B) to 50-60%
of the control values as determined by angiography. The angiographic data correlated
well with the true volumes obtained by water displacement. This major reduction of
LA volume caused small but constant hemodynamic changes. Although the LA stroke volume
decreased by 50% and the LA/LV volume relation was reduced by 50% (from 0.42 to 0.21),
there was only a slight increase of pulmonary artery pressure (7% in group A and 14%
in group B) and a slight decrease in cardiac index (13% in group A and 10% in group
B) and in left ventricular end-diastolic pressure (9% in group A and 11% in group
B). The reduction of atrial volume results in only minor functional alteration of
the intact heart.
Atrial volume - Hemodynamics - Transpositions of great arteries
