Electromechanical mapping for determination of myocardial contractility and viability. A comparison with echocardiography, myocardial single-photon emission computed tomography, and positron emission tomography.

OBJECTIVE

The purpose of this study was to validate electromechanical viability parameters with combined myocardial perfusion and metabolic imaging and echocardiography.

BACKGROUND

The NOGA System is a catheter-based, non-fluoroscopic, three-dimensional endocardial mapping system. This unique technique allows accurate simultaneous assessment of both local electrical activity and regional contractility.

METHODS

The results of NOGA, myocardial single-photon emission computed tomography (SPECT), positron emission tomography, and echocardiography in 51 patients with coronary artery disease and a pathologic SPECT study were transcribed in a nine-segment bull's-eye projection and compared. The local shortening of normally contracting segments, as shown by echocardiography, was 9.2 +/- 5.1%, which decreased to 6.6 +/- 5.0% and 4.1 +/- 5.2% in hypokinetic and akinetic segments. The highest unipolar voltage (11.2 +/- 5.0 mV) and local shortening (8.2 +/- 5.0%) characterized normally perfused segments. Fixed perfusion defects with normal or limited 18-fluoro-2-deoxy-D-glucose uptake indicating viability had a significantly higher unipolar voltage than did scar tissue (7.25 +/- 2.7 vs. 5.0 +/- 3.1 mV, p = 0.029).

CONCLUSION

Electromechanical parameters sufficiently defined the viability state of the myocardium and showed good concordance with the findings by nuclear perfusion and metabolism imaging and echocardiography. The NOGA technique provides all the relevant information immediately after coronary angiography and enables the physician to proceed with therapy in the same setting.