2017 Volume 21 Issue 1 Pages 69-74
In this case, hemodynamic collapse occurred due to the systolic anterior motion (SAM) of the mitral valve after a mitral valvuloplasty (MVP). Intravenous administration of cibenzoline, a sodium (Na+)-channel blocker, reduced left ventricular outflow tract (LVOT) obstruction and the mitral regurgitation (MR) resulting from the SAM, and the hemodynamic condition was improved.
SAM is a well-known complication after MVP. The Venturi effect created by increasing the blood flow velocity at the narrowed LVOT causes the anterior leaflet of the mitral valve to be drawn into the LVOT. Effective perioperative management suppresses the left ventricular contraction, and increases the pre-load and after-load. This requires discontinuation of inotropic drugs, administration of vasoconstrictors, and expansion of intravascular volume. Considering the pathogenesis of SAM, therapies for hypertrophic obstructive cardiomyopathy, such as a beta (β)-blocker, a calcium antagonist, or a Na+-channel blocker, can be effective for treatment of SAM after MVP. A short-acting β-blocker is convenient, and commonly used for the perioperative management of SAM. The essential cause of SAM after MVP is myocardial hypercontraction rather than tachycardia. A Na+-channel blocker is effective for attenuation of the left ventricular pressure gradient (LVPG) because it has more of a negative inotropic effect than a negative chronotropic effect. Therefore, we suggest that if a β-blocker is unavailable, or is insufficient for decreasing the LVPG, cibenzoline is effective for SAM after MVP.
