Evaluation of inotropic changes in ventricular function by NOGA mapping: comparison with echocardiography

Assessment of left ventricular (LV) function in the catheterization laboratory is important to optimize treatment decisions and guide catheter-based local therapies. NOGA electromechanical mapping was developed to assess LV contraction during catheterization; however, quantitative analysis of its "local shortening" (LS) algorithm and direct comparison with conventional methods are lacking. We evaluated the accuracy of NOGA-based regional and global function by examining its ability to detect pharmacologically induced changes in contractility compared with echocardiography. Ten anesthetized pigs were paced to ensure a constant heart rate throughout the experiment. Electromechanical maps of the LV and short-axis echocardiograms were obtained 1) at baseline, 2) during intravenous dobutamine, and 3) after intravenous propranolol. NOGA LS and ejection fraction (EF) consistently increased under dobutamine and decreased after propranolol. NOGA LS and NOGA and echocardiography circumferential shortening correlated highly with one another (r > 0.80), as did NOGA EF with echocardiography EF (r = 0.92), although absolute values differed somewhat. Thus NOGA-based global and regional function correlates closely with echocardiography and is sensitive to changes in contractility, but, at the upper end of the scale, LV function is underestimated.