Relationship Between Mitral Valve Regurgitant Flow and Peripartum Change in Systemic Vascular Resistance

Homayoun Khanlou, MD, Négar Khanlou, MD, Glenn Eiger, MD

Disclosures

South Med J. 2003;96(3) 

In This Article

Case Report

A 24-year-old Asian-American woman (gravida 2, para 1) was admitted to the hospital because of progressive dyspnea associated with cough for 3 days. Her medical history was significant for rheumatic heart disease with mild mitral regurgitation. Seven days before admission, the patient gave birth to a healthy male infant after 37 weeks of gestation. The pregnancy was uncomplicated, with normal vaginal delivery. An echocardiogram obtained during pregnancy showed mild mitral regurgitation with normal left ventricular function. The mitral valve surface area was 2.0 cm2 with an atrioventricular gradient of 10 mm Hg. She was discharged from the hospital after 72 hours. Five days later, the patient complained of nonproductive cough associated with progressive exertional dyspnea. She did not seek medical attention until 1 day before admission, when the dyspnea became severe.

At admission, the patient was in mild respiratory distress with blood pressure of 120/70 mm Hg, heart rate 95 beats/min, and respiratory rate 26 breaths/min. The patient's body temperature was 37.8°C. On physical examination, there was neither jugular venous distention nor hepatojugular reflux. The heart sounds were normal without S3 or S4 gallops. A Grade 2/6 to 3/6 apical pansystolic murmur radiating to axilla was heard. Chest examination disclosed mild rales over the right lung base, with normal left lung field. The extremities were normal, and in particular, no peripheral edema was noted. The remainder of the physical examination was unremarkable. Complete blood count at admission showed a white blood cell count of 12,100/mm3 (85% granulocytes, 10% lymphocytes), hemoglobin value of 11.5 g/dl, and platelet count of 248,000/ mm3. The serum electrolyte, blood urea nitrogen, and creatinine levels were normal. Arterial blood gas values werepH 7.39, PaO2 92 mm Hg, PaCO2 38 mm Hg, and HCO3 23 mmol/L. Electrocardiogram showed sinus tachycardia with left atrial enlargement. Chest x-ray film showed right basilar interstitial infiltrates. Blood cultures were obtained, and treatment was started empirically with ceftriaxone and erythromycin for possible pneumonia.

Five hours after admission the patient's respiratory condition began to deteriorate, necessitating administration of oxygen via nonbreather mask. Repeat arterial blood gas revealed a pH of 7.36, PaO2 of 55 mm Hg, PaCO2 of 45 mm Hg, and HCO3 26 mmol/L. Another chest film showed increased right lung infiltrates with extension to the left lung field. The electrocardiogram was remarkable only for sinus tachycardia at a rate of 100/min. In the next hour, she became hypotensive, and respiratory distress necessitated endotracheal intubation and mechanical ventilation. Swan-Ganz catheterization showed a mean pulmonary capillary wedge pressure of 27 mm Hg and central venous pressure of 19 mm Hg. Systemic vascular resistance was 1,000 dynes/s/cm2 with cardiac output of 5.6 L/min/m2. She was administered furosemide and dopamine intravenously. Repeat echocardiogram showed normal left ventricular function, severe mitral regurgitation with the mitral valve area of 2.6 cm2, and atrioventricular gradient of 14 mm Hg. Moderate left atrial dilation was noted.

Twenty-four hours later, the patient's condition began to improve, and she required less FiO2. She was successfully extubated 3 days after admission. Infiltrates seen on chest films eventually resolved. Microbiologic cultures (blood, urine, and sputum) remained negative. She was discharged on the seventh day of hospitalization and remained free of symptoms after 6 months of follow-up.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....