The Use of Metaraminol in the Evaluation of Mitral Insufficiency

¹ Division of Clinical Physiology, Memorial Hospital of Long Beach, Long Beach, California 90801

This paper presents a simple technique which is useful in evaluating the degree of mitral insufficiency. The pulmonary capillary peak V pressures before and after the intravenous injection of 1 mg of metaraminol were studied by right and left heart catheterization in 61 patients. The presence of an increase in the V-wave over 10 mm Hg indicated mitral insufficiency in all patients if a cardiomyopathy was excluded. If the left atrium is enlarged, a small degree of insufficiency is likely to be missed, but when the insufficiency is marked, the size of the atrium and its increased compliance is not so likely to attenuate the peaked V-wave. The absence of a rise, however, may be seen in patients with all combinations of insufficiency and left atrial enlargement.