Electromechanical mapping distinguished normal myocardium from subendocardial scar (7.9 mV threshold, 80% sensitivity/specificity) and transmural scar (6.9 mV threshold, 93% sensitivity).
Observational (n=15)
Does left ventricular electromechanical mapping accurately differentiate normal myocardium from subendocardial and transmural scar tissue compared to delayed-enhancement cardiac MRI in patients with stable coronary artery disease?
Left ventricular electromechanical mapping provides unipolar voltage values that can accurately distinguish normal myocardium from subendocardial and transmural infarcts, as validated by delayed-enhancement MRI.
p-value: p=<0.05
BACKGROUND: This study was designed to define myocardial viability and establish practical cut-off values for differentiating normal myocardial tissue from subendocardial and transmural scar tissue by using electromechanical mapping (EMM). We validated our results by delayed-enhancement cardiac MRI (DE-MRI). METHODS AND RESULTS: We prospectively studied 15 ambulatory patients with stable coronary disease who were candidates for cardiac catheterization. Within 48 hours of EMM, DE-MRI was performed. Using EMM software, we created a bull's eye precisely matched to that generated by DE-MRI. Segment by segment, we compared the MRI results to the corresponding unipolar voltage value for that same segment in the EMM bull's eye. Of 300 total segments, 275 were compared. The segments were divided into normal (n=211), subendocardial scar (n=49), and transmural scar (n=15). We found that subendocardial (6.8+/-2.9 mV) and transmural (4.6+/-1.9 mV) scar segments had significantly less unipolar voltage than normal (11.6+/-4.5 mV) segments (P<0.05 for each comparison). When normal myocardium was compared with myocardium with subendocardial scar, the threshold for differentiating between the two areas was 7.9 mV (sensitivity, 80%; specificity, 80%). Comparison of normal tissue to transmural scar yielded a threshold of 6.9 mV (sensitivity, 93%; specificity, 88%). CONCLUSIONS: Our results demonstrate that normal myocardium can be accurately distinguished from myocardium with subendocardial or transmural infarcts on the basis of unipolar voltage values obtained through EMM. This is the first study to validate these results by using cardiac DE-MRI in humans.
Perin et al. (Tue,) conducted a observational in Stable coronary artery disease (n=15). Electromechanical mapping (EMM) vs. Delayed-enhancement cardiac MRI (DE-MRI) was evaluated on Unipolar voltage values for differentiating normal myocardial tissue from subendocardial and transmural scar tissue (p=<0.05). Electromechanical mapping distinguished normal myocardium from subendocardial scar (7.9 mV threshold, 80% sensitivity/specificity) and transmural scar (6.9 mV threshold, 93% sensitivity).