PubMed2000
GENERAL PRINCIPLES: The first step is to determine the absence or the minimal nature of the functional impairment from history taking and, for doubtful cases, with an exercise test. Therapeutic indications differ depending on the valvular lesion. AORTIC STENOSIS: Surgery is indicated only for severe aortic stenosis or in cases with a particular risk. Indications for surgery are: false asymptomatic patients with a positive exercise test, patients with abnormal hemodynamic and/or rhythm response to an exercise test (decrease in systolic pressure > 10 mmHg, severe ventricular arrhythmia), aortic stenosis with left ventricular ejection fraction < 50%, aortic stenosis associated with severe coronary artery disease amendable with bypass surgery. MITRAL STENOSIS: The advent of percutaneous mitral commissurotomy has totally changed the treatment of mitral stenosis. This new method can be proposed for stenotic but flexible mitral valves with no major lesion of the lower valvular apparatus or for more advanced valve disease with a risk of hemodynamic failure or thromboembolism. MITRAL INSUFFICIENCY: When mitral leakage is the only valvular defect, surgery is indicated if the volume regurgitated is important as assessed clinically and by echocardiography. Conservative surgery is preferred due to the low risk and the high probability of good long term outcome. Factors to take into account include: the experience of the surgical team in this field, the etiology of mitral insufficiency, the impact on the cardiac condition. Surgery should be performed before the development of atrial fibrillation, major cardiomegaly, left ventricular dilatation (end systolic diameter > 45 mm), or an alteration of the ejection fraction (< 60%). AORTIC INSUFFICIENCY: Cases of the aortic insufficiency should be differentiated according to the state of the ascending aorta. Annuloaortic ectasia requires surgery when the diameter reaches = 50-55 mm (depending on the authors). For valve dysplasia with non aneurysmal cylindrical dilatation of the ascending aorta, the indication for surgery depends on the progressive aggravation of the aortic dilatation. For cases with unique valve lesions, the indication for surgical repair of aortic insufficiency depends on the impact on the left ventricle. Indications for surgery include major radiographic cardiomegaly (cardio-thoracic ratio > 0.58), echocardiographic evidence of major left ventricular dilatation (end diastolic diameter > 75 mm and end systolic diameter > 55 mm), or an alteration of the systolic function (ejection fraction < 0.50 or 0.55). SPECIAL SITUATIONS: In disease states associating stenosis and insufficiency, valve replacement is often the only possibility. Careful patient selection is the rule. Surgery is often needed for cases with multiple valve involvement where different therapeutic options can be used for the different valves. The dominant lesion and the degree of heart dilatation and dysfunction guide decision making.