Electromechanical assessment of left ventricular function following successful percutaneous coronary...

Percutaneous electromechanical mapping was applied to evaluate the impact of coronary revascularization on electrical and mechanical parameters in patients with prior myocardial infarction. In 15 patients with prior (> or = 4 weeks) myocardial Q-wave infarction and regional wall motion abnormalities, left ventricular endocardial mapping was performed immediately prior to percutaneous coronary revascularization. Patients underwent repetitive mapping during 6-month follow-up angiography with good revascularization results in all patients. Mean regional unipolar electrogram (UP) amplitude of all regions remained unchanged (10.4 +/- 4.2 mV prerevascularization vs. 10.2 +/- 4.4 mV postrevascularization), whereas mean local shortening (LS) of all regions increased from 6.0% +/- 5.8% to 9.7% +/- 5.3% (P < 0.001). The percentage of electromechanical match regions (LS < 6% and UP < 9 mV) remained unchanged after revascularization (15% vs. 10%; NS), whereas the percentage of mismatch regions (LS < 6% and UP > 9 mV) declined from 38% to 10% (P < 0.0001). We conclude that electromechanical mapping allows the sensitive detection of improved mechanical function after successful revascularization. Electrical activity remains unchanged 6 months after revascularization and the number of regions with an electromechanical mismatch decrease.