Indications for surgery in obstructive hypertrophic cardiomyopathy

Abstract

ystolic anterior motion of the mitral valve is caused by an abnormal overlap of the inflow and outflow portions of the left ventricle (LV).1-4 Thickening of the septum and anterior position of the mitral valve in the LV cavity caused by mitral/submitral anomalies preposition the tip of the leaflets into the LV ejection stream, where they are swept by flow into the septum. Once they hit the septum, they are forced further into the wall by the pressure difference across the outflow tract. Abolishing or delaying systolic anterior motion is the goal of all treatment for obstructive hypertrophic cardiomyopathy (HCM). Pharmacotherapy with negative inotropes decreases early systolic ejection acceleration, decreasing drag forces on the leaflets, thus allowing the restraining force of the chordae and papillary muscles to reassert their posteriorly directed restraint. Extended surgical septal myectomy, often now performed with ancillary mitral repair, is the most complete and durable method to separate the inflow and outflow portions of the LV.5,6 There is no question that it is highly effective at relieving symptoms; in our practice, 550 patients with moderate or severe symptoms have had surgery.7 The questions posed by the current article by Alashi et al in this issue of the Journal of the American Heart Association (JAHA) are which patients with obstruction should have surgery and whether surgery should be applied early in their course for New York Heart Association I or II symptoms, or later when symptoms are moderate or severe.8 second is to alleviate symptoms. On both counts, this article fails to convince this author that early surgery is preferable to stepped management comprised of aggressive pharmacotherapy followed by surgery, if needed, for patients with resistant symptoms.