Original article Correlation between electrical and mechanical properties of the left ventricle in patients with postinfarction ventricular tachycardia

Abstract

Background: Electroanatomical mapping allows differentiation between viable and scarred myocardium. Echocardiography is widely used to assess myocardial contractility. The relationship between electrophysiological and echocardiographic assessment of left ventricular function has not yet been well established.
Aim: To correlate mechanical and electrical function of the left ventricle in patients with postinfarction ventricular tachycardia and to assess clinical, echocardiographic and angiographic parameters affecting regional electrical function.
Methods: In 32 patients (25 males, 64±9 years old) mean unipolar (UP) and bipolar (BP) voltages were obtained with electroanatomical mapping (CARTO system) for a 12-segment model and compared with segmental wall motion function scored as normal, hypokinetic and a- or dyskinetic. UP voltage in individual groups of segments was: 7.8±4.2 mV, 6.5±4.2 mV, 4.7±2.5 mV, p <0.01 and for BP voltage 2.1±1.5 mV, 1.9±1.9 mV, 1.1±1.0 mV, p <0.01, respectively. Left ventricular ejection fraction ≤30%, end-diastolic diameter >56 mm, previous inferior or anterior myocardial infarction (MI), MI ≤5 years and open infarct-related artery were associated with lower voltage in normokinetic segments.
Conclusions: Segments with advanced systolic dysfunction had significantly lower uni- and bipolar voltage than normo- and hypokinetic segments. However, preserved local electrical function could be found in a/dyskinetic regions. Left ventricular remodelling, time and location of MI and patency of infarct-related artery influenced voltage in normokinetic segments.