Transesophageal echocardiography: the expanding role of ultrasounds in the operating room

The clinica! assessment of myocardial perfusion is a step of pararnount importance in the diagnosis of cor­ onary artery disease (CAD). The non invasive techni­ ques available today give indirect information about perfusion and Jack of sensitivity and specificity. The gold-standard in the diagnosis of CAD, coronary an­ giography, provides semiquantitative information on the anatomy of the major coronary vessels but cannot predict the physiologic effect of the majority of cor­ onary stenoses1 • Coronary blood flow (CBF) in fact depends not only on the anatomy of the epicardial vessels but also on other variables such as the microcir­ culation status, the viability of the underlying myocar­ dium and the regional wall stress. Moreover, routine angiographic interpretation lacks of standardization and ìs affected by a considerable imer and ìntraobserver variabilityl. Computerized quantitative angiography may overcome these limitations but cannot give definite information about flow