PubMed1976
In 12 patients with mitral stenosis left ventricular performance was assessed by pharmacologically (Methoxamine) induced increased afterload. At rest ventricular enddiastolic pressure (6.2 +/- 3.1 mm Hg), left ventricular enddiastolic volume (68 +/- 20 ml/m2), endsystolic volume (26 +/- 11 ml/m2) and left ventricular ejection fraction (0.63 +/- 0.06) were normal in each subject. Methoxamine induced a mean increment in peak systolic atrial pressure of 65 mm Hg. Left ventricular stroke volume, stroke work, stroke power, enddiastolic pressure and volume increased with Methoxamine in each patient. The mean left ventricular ejection fraction remained unchanged for the group and remained within the normal range for all patients. No difference was observed between the response of the mitral stenosis group and a control group of 10 normal subjects with the exception of the account of mitral regurgitation during the pressure load in 9 mitral stenosis patients. This study indicates the left ventricle in mitral stenosis is capable of a normal response to a pressure load. No evidence of impaired left ventricular function was detected in this group of patients.