Haemodynamic findings in experimental right ventricular ischaemia after right coronary arterial ligation.

Acute ischaemia limited to the free wall of the right ventricle was produced by right coronary arterial ligation (RCAL) in 20 dogs. Contrast M-mode and cross-sectional echocardiography was performed in 7 cases to investigate the presence of tricuspid insufficiency. The haemodynamic findings obtained with an open pericardium at 15 to 30 min showed increases in right (1.2 +/- 0.5 to 2.7 +/- 0.7 mmHg, P less than 0.01) and left (5.0 +/- 0.8 to 6.6 +/- 0.9 mmHg, P less than 0.05) ventricular end-diastolic pressures, and decreases in heart rate (139 +/- 4.9 to 119 +/- 5.1 bpm, P less than 0.01), cardiac index (106 +/- 6.6 to 81 +/- 7.3 ml min-1 kg-1, P less than 0.01), stroke index (79 +/- 6 to 72 +/- 8 ml X 100 beat-1 kg-1, P less than 0.02), right (23.8 +/- 1.5 to 19.4 +/- 1.5 mmHg, P less than 0.01) and left (109 +/- 7.2 to 95 +/- 8.2 mmHg, P less than 0.05) ventricular systolic pressures and right ventricular stroke work index (18.3 +/- 2.4 to 11.4 +/- 1.8 g m kg-1, P less than 0.01). In 6 of 15 cases the 'y' descent became deeper than the 'x' descent in right atrial pressure (RAP). Tricuspid insufficiency grade I-II/IV was present in 3 of 7 cases, 2 of them with a 'y' greater than 'x' in RAP. Right ventricular mechanical alternans, probably secondary to a decrease in contractility, appeared in 10 of 20 cases after RCAL.(ABSTRACT TRUNCATED AT 250 WORDS)