MIXED AORTIC AND MITRAL VALVE DISEASE

SALIENT FEATURES

· Pulse may be small volume (due to either dominant aortic stenosis or mitral stenosis), regular or

irregularly irregular.

· Apex beat may be displaced.

- Left parasternal heave.

· 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 on end expiration with the patient sitting forward.

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:

· Atrial fibrillation.

· Absence of left ventricular hypertrophy in patients with left heart failure.

· Female sex.

· Giant-sized left atrium.

· Calcification of the mitral valve.

· Absence of aortic valve calcification in the symptomatic patient.

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 hyper-trophy 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 stem)sis, the murmur of aortic stenosis may be mistaken for mitral regurgitation

(Circtdation1998: 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 ahnost always the result of rheumatic heart disease

(Circulatiot~ 1998' 98:1949-84).

Combined mitral stenosis and aortic regurgitation

The combination of severe mitral stenosis and severe aortic regurgitation may present with confusing

pathophysiology and often leads to misdiagnosis. Mitral stenosis restricts left ventricular filling and so

diminishes the impact of the aortic regurgitation on left ventricular volume (J Am Coil CaMiol 1984: 3:

703-l l). Thus, even severe aortic regurgitation may fail to cause a hyperdynamic circulation, causing

typical signs of aortic regurgitation to be absent during physical examination (Circulation 1998; 98:

1949-84).

Combined mitral and aortic regurgitation

Both lesions cause left ventricular dilatation, but aortic regurgitation causes systolic hypertension and

mild left ventricular thickness. Treatment depends on the dominant lesion and consists of treating

primarily that lesion.

Combined aortic stenosis and mitral regurgitation

The aetiology includes rheumatic heart disease, congenital AS with mitral valve prolapse in young

patients and degenerative AS and MR in the elderly, when severe AS will worsen the degree of MR. MR

may also cause difficulty in assessing the severity of AS because of reduced forward flow. MR will also

enhance LV ejection performance, thereby masking the early development of LV systolic dysfunction

caused by AS (J Am Coil Cm'diol 1998; 32:1486-588).

Treatment:

· In patients with severe AS and severe MR with symptoms, LV dysfunction or pulmonary hypertension:

combined AVR and MVR or mitral valve repair.

· In patients with severe AS and milder degrees of MR, the severity of mitral regurgitation nlay

improve with isolated AVR, particularly when there is m)rmal 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, AVR should be performed.

In patients with less severe gradients, intraoperative TEE and visual assessment by the surgeon may

be necessary to determine the need for AVR (Circulation 1998; 98: 1949-84).

DIAGNOSIS

This patient has mixed mitral valve and aortic valve disease (lesion) of rheumatic aetiology with a

dominant mitral regurgitation as evidenced by the hyperdynamic circulation. The patient is in cardiac

failure (functional status).

QUESTIONS

Mention a few causes of combined aortic and mitral valve disease.

· Rheumatic valvular disease.

· Infective endocarditis.

· Collagen degenerative disorder, e.g. Marfan's syndrome.

· Calcific changes in the aortic and mitral valve apparatus.

What are the indications for surgery?

· New York Heart Association (NYHA) class I11 status.

· Class Il status where there is volume overload of the left ventricle, e.g. in severe aortic regurgitation

with moderate mitral valve disease or severe mitral regurgitation with moderate aortic stenosis and

regurgitation.