Anatomic Correlates of Mitral Systolic Anterior Motion in Transposition of the Great Arteries Following Atrial Switch Operation

Introduction:We sought to investigate whether the development of sub-pulmonic systolic anterior motion(SAM)may be inherent to the anatomy of the the mitral valve(MV)or affected by external factors,such as a dilated right ventricle or chest abnormalities in d-looped transposition of the great arteries post atrial switch operation(d-TGA/AtS).Methods:Analysis was performed of clinical and cardiac imaging studies acquired on 19 adult patients with d-TGA/AtS(age 42±6 years old,56%male)between 2015–2019.Echocardiography data included mitral apparatus anatomy,and CT/MRI data included biventricular dimensions,function,and Haller index(HI)for pectus deformity.Results:Patients with leaflet SAM(n=6)compared to patients without SAM(n=13)had higher MV protrusion height(2.3±0.5 vs.1.5±0.4 cm,p≤0.01)and longer anterior MV leaflet length(3.1±0.4 cm vs.2.6±0.3 cm p≤0.05),when compared to those without.CT/MRI showed higher sub-pulmonic left ventricular ejection fraction(LVEF)in the SAM group(71%±8%vs.54%±7%,respectively).RV size and function,significant chest deformity(HI>3.5),presence of a ventricular lead pacemaker,and septal thickness did not play a role in development of SAM.Conclusions:An elongated mitral apparatus is associated with the development of SAM,and the development of left ventricular outflow tract obstruction(LVOTO),in d-TGA/AtS.LV hyperkinesia is associated with SAM.Systemic RV dimensions,septal thickness,and degree of chest deformity did not differ significantly between subjects with SAM and those without.

Surgical outcomes and strategy of hypertrophic obstructive cardiomyopathy

Objective： To evaluate the surgical clinical results of hypertrophic obstructive cardiomyopathy. Methods： We retrospectively collected data on 24 patients who underwent surgical management in the past ten years in two hospitals in China and Madras Medical Mission in India. Myomectomy was carried out on all patients. Among them 3 patients underwent mitral valve replacement; 2 patients underwent mitral valve repair （anterior mitral leaflet plication）; 2 patients underwent aortic valve replacement; 1 patient underwent aortic valve repair; 2 patients underwent aortic root replacement; 1 patient underwent Bentall＇s procedure and 1 patient underwent coronary artery bypass grafting because of a breached muscle bridge, Results： One patient died of post-operative heart failure. The mean follow-up time was 4.3 years, There was significant improvement in the symptomatic status. Sixteen patients were asymptomatic with good effort tolerance and only four patients had New York heart association （NYHA） Classes Ⅰ-Ⅱ due to associated valvular lesions, Conclusion： Our experience proved that symptomatic hypertrophic obstructive cardiomyopathy or non-symptomatic hypertrophic obstructive cardiomyopathy with combined heart disease is indication for surgery as surgical intervention could get better clinical results in this kind of patients compared with other non-surgical method because it beneficially reduces the systolic anterior motion （SAM） of the mitral valve leaflet, which could not be avoided by other non-surgical treatment.