ANALYSIS OF RIGHT-VENTRICULAR KINESIS BY MEANS OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY - PRESENT PROBLEMS AND PERSPECTIVES

The evaluation of right ventricular (RV) kinesis by two-dimensional echocardiography represents a difficult task. Transthoracic echocardiography can visualize the RV in several projections, but the image quality and the variability of imaging views usually do not allow quantitative analysis. We investigated the potential of transesophageal echocardiography (TEE) for evaluating RV global function and regional kinesis, in 32 controls and in 16 patients with inferior myocardial infarction (MI) and asynergy involving the inferior wall of both ventricles. Good-quality images of at least one horizontal section of the RV were obtained in 73% of subjects by conventional, 90-degrees sector and in 100% of subjects by wide-angle, ''panoramic'' sector. Images of the RV in short-axis view at medium level were acquired and evaluated in 93% of cases, but at basal and apical levels only in 67% and 39%, respectively. The low percentage of successful detection and evaluation of the RV at apical level can be explained by prominent motion and trabeculation of the apex. Global systolic area changes (SAC) in controls attained similar values at apical and medium levels (60% and 59%, respectively), but were significantly lower (48%, P < 0.05) at basal level. In patients with previous inferior MI and inferoposterior asynergy, global SAC were significantly (P < 0.01) lower at medium and basal levels (32% and 27%, respectively) compared with controls. Regional kinesis of RV was assessed as segmental SAC in 12 different segments, by fixed and float system of center of cavity. In controls, the fixed system underestimated kinesis of inferior and septal segments and overestimated kinesis of anterolateral segments, due to leftward translation and inferior rotation of the RV during systole. Float system showed almost concentric kinesis of the RV, with segmental SAC between 53% and 66%. In patients with RV asynergy, the fixed system confirmed the ''eyeball'' analysis, while float system tended to mask the asynergy and showed more uniform kinesis, with diffuse decrement in SAC throughout all segments. Further evaluation, also by biplane and omniplane probes, may help overcome the limitations of the present method for a comprehensive analysis of RV kinesis. TEE, however, already allows improving the echocardiographic assessment of RV kinesis and appears to be a promising tool, and potentially a reference technique, for investigation of RV kinesis during stress.