[Perioperative management for patients with hypertrophic cardiomyopathy]

Hypertrophic cardiomyopathy is a common inherited cardiovascular disease present in one in 500 of the general population. It is caused by more than 1,400 mutations in 11 or more genes encoding proteins of the cardiac sarcomere. In the absence of evidence of any other cardiac or systemic disease that could have resulted in the hypertrophic event, diagnosis of hypertrophic cardiomyopathy requires a hypertrophied non-dilated left ventricle. It is associated with a significant risk for anesthesia. During anesthesia in patients diagnosed with hypertrophic cardiomyopathy, it is essential to maintain relatively slow heart rate, prevent hypovolemia, maintain or increase systemic vascular resistance, and avoid propofol as the sole anesthetic agent. Hence, balanced anesthesia is preferable in these patients. Furthermore, transesophageal echocardiography is very useful for intraoperative assessment and development of a strategy for improving left ventricular outflow tract obstruction (LVOTO) and mitral regurgitation (MR). LVOTO with MR resulting from systolic anterior motion (SAM) of the mitral valve often leads to hemodynamic collapse. Although patients who develop SAM have been managed with intravenous volume loading, reduction/discontinuation of inotropic drugs, and increasing afterload, these strategies have often been ineffective. Beta blockers and cibenzoline, an antiarrhythmic drug, decrease myocardial contraction, attenuate SAM, and improve hemodynamics.