Morbidity, mortality and management of acute mitral regurgitation with pregnancy

Abstract

M itral valve regurgitation (MR) is the leaking or backflow of blood through the valve between the upper left heart chamber (atrium) and the lower left heart chamber (ventricle). If serious, this condition can lead to a backup of blood in the left atrium and the lungs, cause enlargement of and damage to the left ventricle, and lead to heart failure.Mitral valve regurgitation can either be ongoing (chronic) or sudden (acute). Chronic MR develops slowly, possibly over decades, and symptoms, such as shortness of breath, fatigue, and swelling in the feet and ankles, may never appear. Acute MR is a medical emergency that requires urgent treatment to repair or replace the mitral valve (Stout and Verrier, 2009).

The degree of hemodynamic deterioration in acute MR depends upon the etiology and degree of MR, which is often dramatic and rapid in onset. An important factor is left atrial compliance, which is usually normal unless the acute regurgitation is superimposed upon chronic MR (Bursi et al,2005).

The pregnancy-induced changes in the cardiovascular system develop primarily to meet the increased metabolic demands of the mother and foetus. Pregnancy is associated also with a 20% decrease in systemic vascular resistance. Despite the increased workload of the heart during gestation and labour, the healthy woman has no impairment of cardiac reserve (Poppas et al,1997).

Valvular heart disease in pregnancy is relatively infrequent, with an incidence of less than 1% (Siu et al,1997).In the developed world, valvular disease in women of childbearing age is often congenitally acquired (Soler-Soler and Galve,2000). Rheumatic heart disease, myxomatous degeneration, previous endocarditis, and bicuspid aortic valves are also encountered. Pregnancy complicated by valvular heart disease tends to have a favorable prognosis if risks are appropriately managed. Management of the pregnant woman with a heart condition requires special expertise, and patients with high-risk conditions should be referred to centers specialized in their care (Windram and Colman, 2014). Mitral regurgitation in pregnancy is usually due to mitral valve prolapse or rheumatic heart disease (Lesniak-Sobelga et al.,2004). It is usually well tolerated during pregnancy due to the decrease in systemic vascular resistance. Asymptomatic patients do not require specific therapy during pregnancy. In the presence of symptomatic left ventricular dysfunction with hemodynamic abnormalities, diuretics, digoxin, hydralazine, and nitrates can be administered. Surgery for mitral valve repair or replacement during pregnancy has been associated with a high incidence of fetal loss and should be considered only in patients with severe symptoms not controlled by medical therapy (Hameed et al.,2000).