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Valvular Heart Diseases and other Cardiac Conditions

Rheumatic valvular heart disease is common in our country, particularly affecting women in younger age group. Hence many of these patients present with these valvular problems during pregnancy.

Mitral Stenosis

Rheumatic ~nitral stenosis is the most conlinon lesion found in pregnancy. [ I ) Most of these patients with moderate to severe mitral stenosis gel worse during pregnancy symptomnticdly, 2) worsening of one or two classes in New York Heart Association Iunctional status]. The gradient across mitral valve may increase gradually secondsuy to physiological increase in the heart rate and blood volume of pregnancy. Increased left atrial pressure and size may lead to atrial xrhythmias - atrial fibrillation in particular,which accelerates ventricular rate and further elevation of left atrial pressure. Increased ventricular rate also coinpromises left ventlicular filling. Decreased colloid osmotic pressure during pregnancy and also excess intravenous fluid administration during peripartum period may lead to pulmonary edema. In addition, increase in rate of prematurity, fetal growth retardation and low neonatal birth weight can occur. In the modern era of improved care and refined methods of treatment mortality in these patients has decreased.

Diagnosis

Diagnosis is based on careful history taking, and clinical examination for evidence of' loud first heart sound, opening snap and presence of inid diastolic murmur with presystolic accentuation, evidence of pulmonary hypertension, tricuspid regurgitation.Chest X-ray is not indicated routinely as radiation is harmful. The electrocardiogratn may show evidence of left atrial enlargement and right ventricular hypertrophy in addition to'diagnosi~lg arrhythmias. The most useful diagnostic modality is ehocardiogram - 2D Echo, which helps in proper assessment of mitral stenosis and ruling out or detecting presence of significant ~nitral regurgitation or othcr valve lesions. Echocardiography is pai-ticularly helpful in assessing whether the patient is suitable for percutaneous balloon valvulo~lasty for assessing echo score. The pliability (mobility of valve), subvalvular patllology, thickening of' valve lcailets and
calcification- all these are taken into account for assessing echo score for recommending for a balloon valvuloplasty - an ccho score of 8 or less, percutaneous initral balloon valvuloplasty is indicated in severe rnitral stenosis with symptoms.

Treatment

The therapeutic aim is to reduce the heart rate and decrease the left atrial pressure.The measures include restriction of physical activity, administration of beta-adrenergic blocking agents, digitalis preparations in patients with atrial fibrillation - these measures control the ventricular rate. Left atrial pressure may be reduced by a decrease in blood volume through restriction of salt intake and r diuretics. Aggressive diuretic use may cause hypovolemia and the use of oral reduction in uteroplacental perfusion. Many patients can be successfully managed by medical t eatment. IIowever in some patients other measures are needed. Percutaneous balloon initral valvuloplasty has been successful in a number of patients with mitral stenosis during pregnancy. Haenlodynamic a11d symptoinatic improvement has been achieved in majority of patients without maternal or fetalPregnancy and Heart Disease

untoward effects. Follow-up of several years has shown normal development of children born to these mothers. Hdwever, coinplications during balloon valvuloplasty have been reported including developinent of maternal arrhythmias,fetal distress, and cardiac tamponade requiring surgical intervention, systemic embolisation and precipitation of labour. The procedure is to be avoided if possible during first trimester and the procedure is done by experienced operaters with proper shielding of abdominal and pelvic regions to avoid radiationexposure. The procedure also can be done under echocardiographic guidance,which will avoid radiation hazards.Mitral valve repair or replacement is indicated in selective patients who are not suitable for balloon valvuloplasty and who are refractory to medical therapy.Normal vaginal delive~y can be managed in patients with mitral stenosis with medications and hen~odynamic monito~.ing. Epidural anesthesia is recommended both for vaginal delivery and abdominal delivery. Epidural anesthesia may cause systemic vasodilatation, which may result in fall in pulmonary arterial and left atiial pressures.

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