7 Mixed mitral and aortic valve disease
Salient features
• Pulse may be small volume (from either dominant aortic stenosis or mitral stenosis), regular or irregularly irregular
• Mid-diastolic murmur of mitral stenosis
• Pansystolic murmur of mitral regurgitation
• Ejection systolic murmur of aortic stenosis at the base of the heart
• Early diastolic murmur of aortic regurgitation heard with the patient sitting forward on end expiration.
Note
• If the apex beat is not displaced in such mixed lesions, then mitral stenosis is the dominant lesion. (However, if the mitral stenosis developed earlier it can mask the signs of a significant stenosis.)
• In aortic stenosis, the murmur of mitral stenosis may be diminished or absent. The presence of the following features should alert the clinician to a coexisting mitral stenosis because they are not commonly associated with isolated aortic stenosis:
Combined mitral stenosis and aortic stenosis
• Severe mitral stenosis and low cardiac output may mask moderate to severe aortic stenosis. A history of angina, syncope or ECG evidence of left ventricular hypertrophy or calcification of the aortic valve on the chest radiograph suggests the presence of aortic stenosis (Circulation 1998;98:1949–84).
• The murmur of aortic stenosis is occasionally better heard at the apex than at the base, particularly in the elderly (Gallavardin phenomenon). When this occurs in younger individuals with a coexisting mitral stenosis, the murmur of aortic stenosis may be mistaken for mitral regurgitation (Circulation 1998;98:1949–84).
• In patients with significant aortic stenosis and mitral stenosis, the physical findings of aortic stenosis generally dominate and those of mitral stenosis may be missed, whereas the symptoms are usually those of mitral stenosis. ‘Combination stenosis’ is almost always caused by rheumatic heart disease (Circulation 1998;98:1949–84).
Combined aortic stenosis and mitral regurgitation
Treatment
• In patients with severe aortic stenosis and severe mitral regurgitation with symptoms, LV dysfunction or pulmonary hypertension: combined aortic and mitral valve replacement or mitral valve repair.
• In patients with severe aortic stenosis and milder degrees of mitral regurgitation: the severity of mitral regurgitation may improve with isolated aortic valve replacement, particularly when there is normal mitral valve morphology.
• In patients with mild to moderate aortic stenosis and severe mitral regurgitation in whom surgery on mitral valve is indicated because of symptoms of LV dysfunction or pulmonary hypertension: preoperative assessment of the severity of aortic stenosis may be difficult because of reduced forward stroke volume. If the mean aortic valve gradient is ≥30 mmHg, aortic valve replacement should be performed. In patients with less severe gradients, intraoperative transesophageal echocardiography and visual assessment by the surgeon may be necessary to determine the need for aortic valve replacement (Circulation 1998;98:1949–84).
