Place the animal in the right lateral recumbency on a cardiac mattress so that the point of maximal intensity [PMI] of the heartbeat is centered over the cardiac cutout in the cardiac mattress.

• 让动物保持在右侧卧摆位，放在一个心脏检查专用的床垫，所以心跳强度最高的点[PMI]，就正对着，床垫为心脏检查，专门切割开位置的中央。