Double orifice mitral valve is usually an asymptomatic entity unless accompanied by mitral valve stenosis, regurgitation, or a concomitant congenital cardiac anomaly. In patients with an associated congenital heart defect, it is usual for that particular disorder to manifest on clinical examination as there are no signs specific to DOMV. In isolated DOMV, the extent of symptoms depends on the grade of left atrial pressure resulting in pulmonary congestion. Symptoms are primarily due to diminished cardiac output and can range from tachypnea, dyspnea, and wheezing to poor feeding and failure to thrive in the pediatric population. In asymptomatic patients, the physical examination may be completely unremarkable as isolated DOMV is benign, even to cardiac auscultation. However, if complicated by mitral valve stenosis (MS), one may appreciate the murmur of MS, a low pitched mid-diastolic murmur best heard at the apex. The same can be said for DOMV with mitral regurgitation (MR), a blowing pansystolic murmur is appreciated at the apical region. As patients develop symptoms, one may find clinical signs of heart failure such as increased work of breathing, peripheral cyanosis, increased jugular venous pressure, palpation of a parasternal heave, pulmonary crackles on auscultation as well as evidence of hypervolemia such as peripheral edema.

Transthoracic echocardiography (TTE), whether two dimensional (2D) or three dimensional (3D) remains the mainstay of assessing for double orifice mitral valve.[11] The double orifices of the DOMV are best assessed in the parasternal short-axis view; however, for adequate visualization of the sub-valvular apparatus, the apical and subcostal 4-chamber views are useful. 3D TTE is used as an adjunct to 2D TTE as it can provide a more vivid assessment of the mitral valve anatomy and function. 3D TTE can more accurately assess the size and spatial relationships of the mitral valve and intracardiac structures, allowing for closer inspection of the chordal attachments as well as abnormalities of the sub-valvular apparatus.[1]

With the addition of color Doppler, one can gain important information about flow through the mitral valve and can add valuable information regarding valve regurgitation or stenosis. Preoperative transesophageal echocardiography (TEE) is generally unnecessary; however, an intraoperative approach is routinely used to confirm preoperative echocardiographic findings.[12] Cardiac magnetic resonance imaging (MRI) adds little and generally not pursued.[13] Other nonspecific data can be acquired with the use of a chest X-ray and an electrocardiogram. For instance, a chest X-ray may reveal left atrial enlargement along with evidence of pulmonary congestion such as upper lobe diversion, increased interstitial markings, and Kerley B lines. It is important to understand that an electrocardiogram will be normal in isolated DOMV, however possible findings include P mitrale (if left atrial enlargement is present) as well as voltage criteria for left ventricular hypertrophy (if mitral incompetence is severe enough).

Management of a double orifice mitral valve is primarily based on whether patients are symptomatic or not, which in turn directly correlates to the degree of mitral valve dysfunction. For asymptomatic patients, interval TTE is recommended; however, there are no current guidelines specifically addressing how frequent. Management of symptomatic DOMV involves medical therapy, non-invasive intervention, or surgical approach.

The purpose of medical therapy is to treat symptoms of heart failure and pulmonary congestion until a more definitive treatment modality is sort for the mitral valve dysfunction. Medical therapy is especially important in the pediatric population as control of congestive heart failure symptoms is crucial until an infant becomes of age for specific valve intervention. In cases of DOMV with mitral valve stenosis, the use of percutaneous transcatheter balloon dilatation has been shown as an appropriate tool to relieve the obstruction. If balloon dilatation is not practicable or unsuccessful, surgical mitral valvuloplasty or valve replacement may have a role.[4]

All symptomatic patients with a regurgitant valve should be considered for surgical repair with leaflet plication and possible division of the bridging tissue.[14][15] As it pertains to DOMV, surgical closure of one of the orifices might lead to the acute diminution of the mitral valve area with a resultant stenotic flow.[16]

Double orifice mitral valve is a unique disorder; however, its symptomatology is very nonspecific. As stated above, the development of symptoms correlates to the degree of mitral valve dysfunction, the left atrial pressure, and the degree of pulmonary venous congestion. Therefore, in adults, it is important to consider other causes of mitral valve disease such as rheumatic heart disease, functional MR, myocardial ischemia, annular calcifications in the elderly, connective tissue disorders, myxomatous degeneration and infective endocarditis.[17] In the pediatric population, DOMV should be considered when another congenital heart disease is present. These include coarctation of the aorta, patent ductus arteriosus, or a bicuspid aortic valve as well as atrioventricular septal defect.

In asymptomatic patients without mitral valve dysfunction, the prognosis is reassuring. However, at the time of writing, there are no prospective studies done to aid in a timeline for progression from diagnosis of double orifice mitral valve to mitral valve dysfunction as some patients develop mitral valve dysfunction early in infancy and others, in adulthood.[15][18] With the advent of non-invasive techniques, the survival rate with intervention for mitral valve dysfunction is much higher than with surgical valve replacement.

Complications of double orifice mitral valve include mitral valve dysfunction (mitral stenosis/mitral valve regurgitation) with resulting pulmonary edema and congestive heart failure. There have been cases of atrial arrhythmias such as atrial fibrillation and atrial flutter as a direct result of DOMV, and as a result, patients may experience embolic strokes.[19]

Double orifice mitral valve is most commonly found incidentally while investigating other possible cardiac pathologies. This anomaly, by itself, is asymptomatic; however, it can lead to mitral valve dysfunction. It is at this juncture that intervention is pursued with medicines and some sort of valve intervention, whether noninvasive or surgical. At the time of diagnosis, patients should be referred to a cardiologist and a cardiothoracic surgeon and followed closely with interval TTE. For symptomatic patients, physical activity is restricted, and patients are advised to seek medical care if they develop signs of heart failure. This may include but is not limited to shortness of breath, cough, leg swelling, and weight gain. At this time, medications may be required to help with heart failure and serve as an interim measure until the dysfunctional mitral valve can be repaired.

To ensure appropriate patient care and improvement in outcomes, it is prudent to have a team approach when managing a patient with double orifice mitral valve. DOMV is predominantly an asymptomatic condition and given is low incidence rate, echocardiography technicians and cardiologists must be on high alert, especially when obtaining the parasternal short-axis views, scanning from the base to the apex to assess the sub-valvular structures. Early referral to a cardiologist and cardiothoracic surgeon is warranted. DOMV is usually a disorder that is managed as an outpatient with inpatient care designated for acutely decompensated heart failure and further investigative workup. At the time of writing, valve intervention is only recommended at the stage of valve dysfunction, and as such, it is imperative to have a thorough risk vs. benefit discussion with a cardiologist, cardiothoracic surgeon and of course, the patient, as to which form of valve intervention is best suited for the patient’s best outcome.