Experimental Aortic Stenosis and Corresponding Left Ventricular Hypertrophy in Sheep

Abstract

Left ventricular hypertrophy (LVH) is an independent cardiac risk factor. A simple standard experimental model of inducing LVH for further studies using experimental aortic stenosis in sheep was performed. The aim of this study is to describe animal-specific requirements as well as perioperative therapy, postoperative care, and the use of echocardiography for routine follow-up examinations. Supracoronary aortic banding was performed in 55 female sheep at an age of 6 to 8 months. General anesthesia and an antero-lateral thoracotomy were used. The objective was to achieve pressure gradients of 20 to 30 mm Hg. In addition a 4th intercostal space rib window was created to improve echocardiographic vision. The operations were completed successfully in all animals. Intraoperatively, little severe arrhythmia occurred. During the follow-up interval of 8 +/- 1.3 months, 8 animals died, due to incomplete perforation of the ascending aorta (3), chronic heart failure (2), pericardial cyst (1), and respiratory failure and infection (2). All remaining animals were amenable for further studies. Severe LVH was diagnosed with routine echocardiography on follow-up. Thus, experimental aortic stenosis in sheep is a safe and relatively simple technique to generate stable LVH. Echocardiography is an easy tool for follow-up evaluations. Due to low complication rates, the sheep model is well suited for further research in LVH.