Hemodynamic evaluation of acute mitral valve insufficiency model induced by chordae tendinae rupture in normal dogs

The study was to observe hemodynamic alterations of cardiac function to design a model of canine mitral valve insufficiency (MVI) based on chordae tendinae rupture (CTR). Ten healthy beagles with normal heart function were used in this study. To measure hemodynamics, the patient monitor was equipped for invasive blood pressure and a Swan-Ganz catheter. Hemodynamic alterations were checked promptly during CTR procedures. MVI model was made by transection of the chordae tendinae with small arthroscopy hook knife through 5^th intercostal open chest. Color Doppler at the level of the mitral valve showed high-velocity regurgitant flow immediately after CTR at intraoperative echocardiography. In hemodynamic measurements, pulmonary capillary wedge pressure (PCWP) was significantly increased, while mean arterial pressure (MAP), venous pressure (VP), pulmonary arterial pressure (PAP), cardiac output (CO) and cardiac index (CI) were significantly decreased after CTR. It was known that the left atrium was overloaded by regurgitant volume from the left ventricle. In conclusion, the MVI model induced by CTR technique in this study should be used as suitable one for the effective research of canine mitral valve disease. Further study should be needed to measure the chronic alternation of mitral valve in the model.