Persistent Mitral Regurgitation – this is not an uncommon occurence after repair of the mitral valve for regurgitation. The most common cause is the failure of the leaflets to coapt in the left ventricular space. If severe enough, it
requires reoperation for an attempt at re-repair or mitral valve replacement.
Persistent mitral regurgitation can also occur after operation for mital stenosis if there is an excessive commissurotomy.
Persistent Mitral Stenosis – this is not an uncommon occurrence after repair of the mitral valve for stenosis. It is diagnosed usually in the immediate post-operative period by a low cardiac output, a high left atrial pressure, or by transesophageal echocardiogram. Most typically, a full valve mitral valve replacement is performed.
Obstruction of the Left Ventricular Outflow – this occurs when the mitral ring has been “tilted” or when the posterior leaflet is too long, which can functionally push the anterior leaflet into the left ventricular outflow tract. This condition can be detected on transesophageal echocardiogram and manifests as reduced cardiac output and an increased left atrial pressure.
Sometimes, an obstruction of the left ventricular outflow tract is a function of hypovolemia and hypercontractility. Experienced intensivists will attempt to correct any fluid deficits and discontinue inotropic drugs and pressors. In addition, some clinicians advocate the use of beta blockers.
If the problem appears to be refractory, reoperation can be performed to attempt to reduce the height of the posterior leaflet with a sliding valvuloplasty. If this is not successful, the valve should be replaced.