Left ventricular contractility and SVR are usually preserved in MS. If anything, the left ventricle is chronically underloaded. Nevertheless, global systolic dysfunction develops in some MS patients.18
Right ventricular dysfunction probably poses a greater challenge in treating patients with MS than does left ventricular dysfunction. Every effort should be made to avoid increases in pulmonary arterial pressures (e.g., avoid hypoxia, hypercardia, acidosis, lung hyperexpansion, and nitrous oxide).