History
Patients who have double orifice mitral valve (DOMV) without mitral regurgitation or mitral stenosis or a concomitant congenital cardiac anomaly are asymptomatic. [2] Physical findings may only exist if mitral regurgitation or mitral stenosis are present.
The severity of symptoms depends on the degree of left atrial hypertension. Dyspnea, nocturnal cough, and tachypnea occur, related to pulmonary venous congestion and increased lung stiffness. Frequent respiratory infections and wheezing occur, secondary to pulmonary congestion, increased fluid exudation, and airway narrowing. Poor feeding, failure to thrive, fatigue and sweating occur because of heart failure and reduced cardiac output. On occasion, a child with double orifice mitral valve presents with acute pulmonary edema or generalized edema. Hemoptysis and syncope can occur in older patients with double orifice mitral valve.
Double orifice mitral valve is detected in one of three ways. As an associated lesion with other congenital heart defects, especially in the presence of atrioventricular (AV) septal defect or left-sided obstructive lesions. The abnormal mitral valve aggravates the pulmonary congestion and heart failure that occurs in complete AV septal defect or ventricular septal defects (VSDs). In the converse, conditions such as large left-to-right atrial shunts and tetralogy of Fallot with reduced mitral valve flow may mask the presence of double orifice mitral valve. In patients with such conditions, double orifice mitral valve is not detected unless the clinician specifically looks for it.
Double orifice mitral valve may be sought as the anatomic explanation for symptomatic mitral valve disease or discovered as an incidental finding in asymptomatic patients who undergo echocardiography for any reason. [19]
Physical Examination
Physical signs in DOMV with mitral stenosis
Respiratory distress, tachypnea, and subcostal retractions. Reduced pulse volume and peripheral cyanosis indicate diminished cardiac output and poor tissue perfusion. Central cyanosis can develop in the presence of severe pulmonary edema. Jugular venous pressure rises with the onset of right heart failure. Palpation reveals a parasternal heave from the hypertrophied RV and occasionally, a diastolic thrill at the apex.
The first heart sound may be normal or accentuated, while the pulmonary second sound generally is loud because of pulmonary hypertension. Unlike acquired mitral stenosis, an opening snap is not commonly heard.
A low-pitched mid-diastolic murmur of varying intensity is audible at the mitral area. It is often heard best with the patient in the left lateral decubitus position, and it is especially loud when mitral stenosis is associated with a VSD or mitral regurgitation.
In chronic, severe mitral stenosis, signs of tricuspid incompetence, such as systolic expansile pulsation in the jugular vein and liver and a pansystolic murmur at the lower sternal border, appear. This murmur is typically accentuated on inspiration.
Physical signs in DOMV with mitral regurgitation
The patient may present with respiratory distress and pulmonary edema. The pulse is often brisk. The apical impulse is displaced downward and outward and has a hyperdynamic quality because of LV dilatation and hypertrophy. The first and second heart sounds are usually normal in intensity, although the second heart sounds may be widely split. A third heart sound is commonly heard at the apex. A blowing pansystolic murmur is heard at or just inside the apex. It is often conducted toward the sternum rather than toward the axilla.
Severe mitral regurgitation can cause a low-pitched, apical diastolic murmur from large diastolic flow across the mitral valve. Diastolic murmur at apex of the heart (functional MS murmur). Pulmonary hypertension and tricuspid incompetence can occur in MR, though not as commonly or as severely as in MS.
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Double Orifice Mitral Valve. Two-dimensional echocardiogram (apical view) in a patient with duplicate mitral valve. Two mitral valves can be seen opening into the left ventricle. Each valve has a separate annulus, and a separate set of mitral valve leaflets and subvalvar apparatus.
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Double Orifice Mitral Valve. Two-dimensional echocardiogram (parasternal short-axis view) shows a double-orifice mitral valve, the orifice divided by a bridge of tissue.
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Double Orifice Mitral Valve. Two-dimensional echocardiogram of a double-orifice mitral valve (apical view) with color flow mapping, which shows diastolic flow through two separate orifices.
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Double Orifice Mitral Valve. Two-dimensional echocardiogram (parasternal short-axis view) in a patient with duplicate mitral valve. This diastolic frame shows two typical mitral valve orifices opening into the left ventricle. The two orifices are placed apart, unlike the more common type of double orifice mitral valve (see image above) where the orifice is divided by a bridge of tissue.
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Double Orifice Mitral Valve. Real-time two-dimensional echocardiogram (apical view) in a patient with duplicate mitral valve. Two mitral valves can be seen opening into the left ventricle. Each valve has a separate annulus, and a separate set of mitral valve leaflets and subvalvar apparatus.
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Double Orifice Mitral Valve. Real-time two-dimensional echocardiogram (subcostal short-axis view) in a patient with duplicate mitral valve showing two typical mitral valves opening into the left ventricle. The two orifices are placed apart, unlike the more common type of double orifice mitral valve (see the previous image) where the orifice is divided by a bridge of tissue.
