Simple methods to elevate pulmonary arterial pressure by pre- and post-tricuspid shunts in rats

Background: Arteriovenous shunt in the rat is an extremely useful experimental animal model for investigating cardiac hypertrophy as well as the hemodynamics and endocrine aspects of chronic heart failure. Aims: The present study was to develop 2 pre-tricuspid and 1 post-tricuspid models of arteriovenous shunt to induce right ventricular hypertrophy and increase pulmonary blood flow in growing rats. Methods: In the first model, an arteriovenous shunt was created from the common iliac artery to the inferior vena cava (ICS). The second model was shunted from the common carotid artery to the external jugular vein (CJS). A post-tricuspid shunt (the third model) was made by introducing the right common carotid artery into the right ventricular outflow tract (CVS). Results: Four weeks after the shunt surgery, the pulmonary artery pressure was 14.4 ± 0.5 mmHg in the control group, 15.8 ± 0.8 mmHg in the ICS group, 21.2 ± 0.7 mmHg in the CJS group, and 20.2 ± 1.1 mmHg in the CVS group. The percentage of increasing pulmonary blood flow was 33.0 ± 1.0% in the CJS group and 26.9 ± 1.3% in the ICS group four weeks after shunt operation. The oxygen partial pressure of pulmonary artery blood was 30.9 ± 0.7 mmHg in the control group, 33.6 ± 1.0 mmHg in the ICS group, 43.7 ± 1.4 mmHg in the CJS group and 41.1 ± 2.5 mmHg in the CVS group. The CJS and CVS groups had significant right ventricle hypertrophy. Conclusions: These three models can provide for study of the flow-pressure effect of the right heart and pulmonary circulation.