Labor complicated by mitral stenosis

Abstract

A case where a 28-year-old woman presented in labor complicated by mitral stenosis is described. Mitral stenosis is the most commonly encountered valvular lesion in pregnancy.

CASE DESCRIPTION

A 28-year-old woman from Mexico, G2 P1001 at 36 weeks’ gestation, presented to labor and delivery with uterine contractions. The patient denied having any significant medical and/or surgical history. She was mildly tachycardic, and both legs were edematous. Cervical examination disclosed 3 cm dilatation, 80% effacement, and −3 station.

Nine hours after admission, she began complaining of dyspnea with contractions. She revealed being diagnosed with a “heart murmur” at age 18, receiving monthly “injections” with subsequent resolution of the problem, and being discharged by a cardiologist 8 years prior. Repeat physical examination was significant for persistent tachycardia, bilateral crackles at lung bases, leg edema, and jugular vein distention. Her brain natriuretic peptide was 1754 mg/dL, and a portable chest radiograph revealed marked cardiomegaly and mild congestive failure. She was given 20 mg of furosemide as an intravenous bolus. A transthoracic echocardiogram disclosed a moderately dilated left atrium, right atrium, and ventricle; a flattened ventricular septum consistent with right ventricular pressure overload; global left ventricular hypokinesis; a left ventricle ejection fraction of 25% to 30%; and moderately reduced right ventricular systolic function. The mitral valve was thickened and calcified with an area of 1.3 cm², peak velocity of 2.5 m/s, and mean diastolic gradient of 18 mm Hg.

Twelve hours into admission, the patient requested pain relief, which was achieved with a slow, controlled, low-concentration epidural. In preparation for placement of the epidural, we used standard monitors, an arterial line (to closely monitor blood pressures), and a central line (to facilitate placement of a pulmonary artery catheter, which we later placed). She had an assisted vaginal delivery and was taken to the cardiac intensive care unit for escalation of care. There she was started on esmolol and furosemide intravenous infusions, was discharged on day 9, and returned 2 months later for mitral balloon valvuloplasty without further incidence.

DISCUSSION

Mitral stenosis (MS) is the most commonly encountered valvular lesion in pregnancy (1), with the leading cause being attributed to rheumatic heart disease (2). Patients with MS do not tolerate the physiologic changes of pregnancy well, and it is not uncommon for MS to become unmasked for the first time during pregnancy (1). During pregnancy, associated pulmonary hypertension can be exacerbated due to the various hemodynamic changes that occur during gestation, and it carries a substantial health risk to both mother and fetus (3).

When a pregnant woman presents with MS, the mode of delivery is a major determinant of anesthetic management, with vaginal delivery being preferred over cesarean delivery (4, 5). In our case, the patient presented in active labor and after discussion among perinatology, cardiology, and anesthesiology, she was allowed to continue labor, which was quite successful.