Left ventricular electromechanical mapping: preliminary evidence of electromechanical changes after successful coronary intervention.

BACKGROUND: Postinterventional ischemic myocardial dysfunction and its sequelae are still not well understood. METHODS AND
RESULTS: To gain further insight into the immediate physiologic consequences of coronary interventions and to better understand the nature of changes that result from such interventions, we analyzed 96 electromechanical maps from 48 patients before and after successful, uncomplicated percutaneous coronary interventions (PCI). A NOGA system was used to construct the map of the endocardial surface. Reproducibility was confirmed by constructing 10 additional maps in 5 patients who did not undergo an intervening procedure. Discordant areas were defined as those with preserved unipolar voltage (> or =7.5 mV) and diminished linear local shortening (< or =12.5%). On the basis of comparison of the variations in the discordance values (%) in the reproducibility group, patients were considered improved (lower values), worsened (higher values), or unchanged. In the reproducibility group, the mean variation in discordance was 2.18% +/- 1.26%, whereas in the PCI group, it was 21.97% +/- 18.47%. In the PCI group (rotational atherectomy subgroup [n = 10] and stent subgroup [n = 38]), left ventricular discordance values improved in 19 patients (39.6%), worsened in 24 (50%), and remained the same in 5 (10.4%). Of all variables analyzed, only abciximab was significantly associated with postintervention improvement in discordance (P =.02; odds ratio 0.165, 95% CI 0.03-0.88), regardless of the type of intervention performed (P =.61), whereas heparin alone was associated with more discordance after intervention (odds ratio 6.07, 95% CI 1.14-32.40).
CONCLUSIONS: We assessed the effect of percutaneous revascularization on myocardium by use of electromechanical data. For the first time, changes in linear local shortening in areas of preserved unipolar voltage were quantified, and worsening after successful Thrombolysis In Myocardial Infarction grade III coronary interventions was registered. The only variable associated with improvement on electromechanical data after interventions was the use of abciximab. This raises the question of the possible potential of this new diagnostic tool in assessing and quantifying postinterventional microvasculature pathological changes.