Rheumatic endocarditis causes most mitral stenosis lesions. The normal mitral valve surface area is 4.0 cmr, and when stenosis 2 narrows this to <2.5 cmr, symptoms usually develop (Desai, 2000). The contracted valve impedes blood low from the left atrium to the ventricle.
With more severe stenosis, the left atrium dilates, let atrial pressure is chronically elevated, and signiicant passive pulmonary hypertension develops (Table 49-6). These women have a relatively ixed cardiac output, and thus the increased preload of normal pregnancy and other factors that raise cardiac output may cause ventricular failure and pulmonary edema. Indeed, a fourth of women with mitral stenosis have cardiac failure for the irst time during pregnancy (Caulin-Glaser, 1999). he resulting pulmonary venous hypertension and pulmonary edema create symptoms of dyspnea, fatigue, palpitations, cough, and hemoptysis. The classic murmur may not be heard in some women, and this clinical picture at term may be confused with idiopathic peripartum cardiomyopathy (Cunningham, 1986,r2012).
Also with signiicant stenosis, tachycardia shortens ventricular diastolic illing time and elevates the mitral gradient. his too may lead to pulmonary edema. Thus, sinus tachycardia is often treated prophylactically with 3-blocking agents. Atrial tachyarrhythmias, including ibrillation, are common in mitral stenosis and are treated aggressively. Atrial ibrillation also predisposes to mural thrombus formation and cerebrovascular embolization that can cause stroke (Chap. 60, p. 1161). Atrial thrombosis can develop despite a sinus rhythm (Hameed, 2005).
Pregnancy Outcomes 66 newborns who were delivered at term had normal growth and development.
In general, complications are directly associated with the degree2 Labor and delivery are particularly stressful for women withofvalvular stenosis. Women with a mitral-valve area <2 cmrare symptomatic mitral stenosis (Fig. 49-3). Uterine contractionsat greatest risk (Siu, 2001b). In one study of 46 gravidas with increase cardiac output by increasing circulating blood volume.
mitral stenosis, 43 percent developed heart failure, and 20 percent Pain, exertion, and anxiety cause tachycardia with possible ratedeveloped arrhythmias (Hameed, 2001). Fetal-growth restriction 2rrelated heart failure. Epidural analgesia for labor is ideal, but was more common in women with a mitral valve area < 1.0 cmr• fluid overload is avoided. Abrupt expansion in preload mayPrognosis is also related to maternal functional capacity.
raise pulmonary capillary wedge pressure and cause pulmonaryAmong 486 pregnancies complicated by rheumatic heart disedema. Wedge pressures rise immediately postpartum. Oneease-predominantly mitral stenosis-8 of 10 maternal deaths hypothesis for this suggests that the loss of the low-resistance were in women in NYHA classes III or IV (Sawhney, 2003).
placental circulation couples with venous "autotransfusion"