Improved echocardiographic detection and characterization of left ventricular apical thrombi with a 5.0 MHz short-focus transducer.

Abstract

Transthoracic echocardiography is a frequently used technique for detecting ventricular thrombi. This study compares the usefulness of a 5.0 MHz short focal length transducer (5-short) with standard frequency (2.5 or 3.5 MHz) transducers for the detection of left ventricular thrombi. In addition, the effect of body habitus on study quality was evaluated. A consecutive series of 101 patients sent for echocardiographic imaging with the diagnosis of myocardial infarction, dilated cardiomyopathy, or recent suspected embolic event were imaged in the apical four-chamber, apical long-axis, and apical two-chamber views with a standard transducer and also with the 5-short. Out of this group, 16 apical thrombi were identified, six with the 5-short only, three with standard transducers only, and seven by both techniques. The areas of the seven thrombi detected by both transducers were consistently larger when measured on 5-short images compared with standard transducer images (4.6 +/- 2.3 vs 3.7 +/- 2.3 cm2, p = 0.02). In the three studies positive only with the standard transducers, the 5-short demonstrated only prominent trabeculae but no thrombus. The studies positive only with the 5-short had significantly smaller calculated thrombi areas than those visualized by the standard transducers (1.6 +/- 1.2 vs 4.2 +/- 2.1 cm2, p = 0.02). No thrombus was detected by either technique in a normally contracting left ventricular apex. There were significantly fewer studies having near-field artifact when performed by the 5-short compared with those performed with standard transducers (14/101 vs 40/101, p = 0.00004).(ABSTRACT TRUNCATED AT 250 WORDS)