DK2985_C000 1..28 - AlSharqia Echo Club

172 Transesophageal EchocardiographyTEE, as the transesophageal approach allows better visualizationof the mitral apparatus and provides importantinformation about both the severity and the mechanismof the regurgitation before valvular surgery.A. Ventricular Septal DefectA ventricular septal defect (VSD) is a well-recognized complicationof either anterior or inferior wall infarction, occurringin 1–2% of patients. Rupture of the septum typicallyoccurs at the junction of the necrotic and noninfarcted myocardium,within the first week after infarction, and therupture site and adjacent infarct are thinned and aneurysmal.The combination of a first transmural infarction in aterritory supplied by a single diseased coronary vessel andthe absence of collaterals is frequently present (37). Clinically,between two and seven days postinfarction, the patientpresents with a new holosystolic murmur (which may beabsent in extreme shock) and worsening heart failure.Prompt diagnosis is essential because deterioration maybe rapid and the presence of shock is associated with anincreased risk of a fatal outcome. Surgery is warranted inalmost all cases as conservatively treated patients with anacute VSD do poorly. The timing of surgery is crucial,and an approach combining early percutaneous closurewith delayed surgery has now been implemented in manycenters. The VSD usually appears on echocardiography asa single perforation that varies between one to several centimetersin diameter. It is often described as a “through andthrough” hole but the VSD are irregularly shaped and serpiginous.The appearance of the defect may be preceded byformation of a septal aneurysm with thinning, which maybe seen to bulge in the RV during systole. Defects with aserpentine course are more difficult to visualize. When complicatingan anterior infarction, the septal defect is usuallylocated near the apex in association with anterior akinesis(Figs. 8.15–8.19). When a VSD occurs with an inferiorinfarction, the apex is generally spared and the defect is inthe basal septum, generally associated with an extensivearea of inferior wall dyskinesis. Systolic flow accelerationcan be identified by PW Doppler, but color flow Dopplerimaging allows demonstration of the defect site, with aleft-to-right mosaic signal indicating turbulence and isbest seen in the RV (Fig. 8.16). The right ventricular systolicpressure can be estimated from the difference between thesystolic arterial pressure obtained by the cuff method orthe arterial line and the peak transventricular systolic gradientobtained by CW Doppler.(A)(B)LARALVRVVSD(C)(D)VSDRVLVFigure 8.15 A 56-year-old man with acquired ventricular septal defect (VSD) following an anterior myocardial infarction. The VSD islocated at the apex (A, B) and could also be seen in the apical transgastric view using color Doppler (C, D) (LA, left atrium; LV, leftventricle; RA, right atrium; RV, right ventricle).