The pathogenesis of acute pulmonary edema associated with hypertension.

BACKGROUND: Patients with acute pulmonary edema often have marked hypertension but, after reduction of the blood pressure, have a normal left ventricular ejection fraction (> or =0.50). However, the pulmonary edema may not have resulted from isolated diastolic dysfunction but, instead, may be due to transient systolic dysfunction, acute mitral regurgitation, or both.

METHODS: We studied 38 patients (14 men and 24 women; mean [+/-SD] age, 67+/-13 years) with acute pulmonary edema and systolic blood pressure greater than 160 mm Hg. We evaluated the ejection fraction and regional function by two-dimensional Doppler echocardiography, both during the acute episode and one to three days after treatment.

RESULTS: The mean systolic blood pressure was 200+/-26 mm Hg during the initial echocardiographic examination and was reduced to 139+/-17 mm Hg (P< 0.01) at the time of the follow-up examination. Despite the marked difference in blood pressure, the ejection fraction was similar during the acute episode (0.50+/-0.15) and after treatment (0.50+/-0.13). The left ventricular regional wall-motion index (the mean value for 16 segments) was also the same during the acute episode (1.6+/-0.6) and after treatment (1.6+/-0.6). No patient had severe mitral regurgitation during the acute episode. Eighteen patients had a normal ejection fraction (at least 0.50) after treatment. In 16 of these 18 patients, the ejection fraction was at least 0.50 during the acute episode.

CONCLUSIONS: In patients with hypertensive pulmonary edema, a normal ejection fraction after treatment suggests that the edema was due to the exacerbation of diastolic dysfunction by hypertension--not to transient systolic dysfunction or mitral regurgitation.