0071643192.pdf

Mitral Regurgitation

Mitral valve regurgitation (MR) may be acute or chronic. As with aortic regur-

gitation, it is important to make this differentiation as acute MR is a surgical

emergency requiring immediatevalve replacement.

ETIOLOGIES

■ Acute mitral regurgitation

■ Endocarditis

■ Myocardial infarction

■ Trauma

■ Chronic mitral regurgitation

■ Rheumatic heart disease is most common.

■ Other causes include mitral valve prolapse, connective tissue disorders.

PATHOPHYSIOLOGY

■ Acute injury or dysfunction of the valve, papillary muscle, or chordae ten-

dinae →acute valve failure →acute left atrial overload and pulmonary

edema.

■ Chronic valve failure →compensatory dilation of left atrium and gradual

onset of CHF.

ACUTEMITRALREGURGITATION

SYMPTOMS

■ Abrupt onset of dyspnea, tachypnea

■ Cardiogenic shock

■ Chest pain

■ Symptoms of underlying disease process (endocarditis, MI, trauma)

EXAM

■ Loud holosystolic murmur heard best at the apex, with radiation to the

base

■ Left ventricular heave

■ Pulmonary edema

DIAGNOSIS

■ ECG:Absenceof left atrial enlargement and LVH

■ CXR: Normal cardiac silhouette, pulmonary edema

TREATMENT

■ Standard treatment for pulmonary edema

■ Nitroprusside for afterload reduction

■ Dobutamine (in addition to nitroprusside) if hypotensive

■ Intra-aortic balloon pump as bridge to surgery

■ Immediatevalve replacement

■ Treat underlying disease process.

COMPLICATIONS

■ Acute pulmonary edema

■ Cardiogenic shock

CARDIOVASCULAR EMERGENCIES

Acute mitral regurgitation is a

surgical emergency.

Acute mitral regurgitation?

Treat with nitroprusside,

dobutamine (if hypotensive),

and intra-aortic balloon pump

until OR is available.