A new technique for producing pure aortic stenosis in animals

Abstract

To date, techniques used to produce an animal model of valvular aortic stenosis have been unsuccessful. We have developed a new technique for producing pure subcoronary aortic valvular stenosis, which results in left ventricular hypertrophy in a short time. Five adult mongrel dogs weighing 18-24 kg were anesthetized with Brevital (0.5 mg/kg), intubated, and mechanically ventilated with halothane-oxygen. The chest was opened through the right 4th intercostal space, and cardiopulmonary bypass was established between the right atrium and femoral artery. When the esophageal temperature was reduced to about 25 degrees C, the aorta was cross clamped and incised. A piece of Teflon felt covered by pericardium was sutured into each of the sinuses of Valsalva below the coronary orifices. Two to four weeks after the operation, the animals were catheterized. The average pressure gradient between left ventricle (LV) and aorta was 52 +/- 15 mmHg. Mean LV mass-to-body weight ratio was 6.16 +/- 0.28 g/kg vs. 4.24 +/- 0.27 for controls. End-diastolic volume and ejection fraction remained normal, and no aortic regurgitation was seen on aortic root angiography. This preparation creates a hemodynamic representation of valvular aortic stenosis and produces a useful model for examining the myocardial response to this disease. Although hypertrophy develops rapidly, slowly developing hypertrophy may also be possible with this technique.