DK2985_C000 1..28 - AlSharqia Echo Club

220 Transesophageal EchocardiographyMitral Valve ApparatusIn addition to the abnormally large and elongated mitralleaflets, other MV abnormalities can be found. Rupturedchordae, anomalous papillary muscles insertion, leaflet(s)prolapse, or degenerative changes from repeated septalcontact have all been described in association withHOCM and can result in severe MR. Special attentionshould be given when identifying these abnormalities preoperatively,as they will need to be addressed separately toensure complete correction of the MR.Systolic Anterior Motion of the Mitral ValveThe SAM of the MV and its contact with the septum isbest evaluated in the mid-esophageal four-chamber (08)orlong-axis views (1208) (Fig. 10.5). The extent and durationof the mitral–septal contact can also be appreciated usingM-mode of the LV in the same views (Fig. 10.4).A septal contact lasting at least 30% of the systole durationis thought to be necessary to produce significantobstruction. The transgastric long-axis view at 1208 andthe deep transgastric view at 08 both display the LVOTbut the latter is the optimal view to assess the LVOT gradientby TEE.Other FindingsFirst, the LA is often dilated because of associated MR,chronically increased left ventricular diastolic pressureand the presence of atrial fibrillation, which is a frequentcomplication of HCM. Second, as the LVOT obstructionbegins in mid- or late systole, the aortic cusps may closeprematurely as a result of the reduced flow in the latterhalf of the ejection period. This mid-systolic closure isbest appreciated using M-mode of the aortic valve(AoV) at the mid-esophageal long- (1208) or short-axis(308) views. Finally, the right ventricle (RV) and theFigure 10.5 Preoperative transesophageal echocardiographic exam of a 26-year-old man with hypertrophic cardiomyopathy andrefractory symptoms despite optimal medical therapy. (A–B) Mid-esophageal long-axis view with color flow imaging: flow accelerationis already present in the subaortic region. (C) The resected basal septum is shown. (Ao, aorta; LA, left atrium; LV, left ventricle; RV, rightventricle) (Courtesy of Dr. Nancy Poirier).