Alʹmanah Kliničeskoj Mediciny (Feb 2016)
CONCORDANCE OF ELECTROPHYSIOLOGICAL AND PERFUSION ABNORMALITIES IN THE LEFT VENTRICULAR MYOCARDIUM IN POST INFARCTION ANEURYSMS WITH VENTRICULAR TACHYCARDIA
Abstract
Background: Ventricular tachycardia in patients with post infarction aneurysm of the left ventricle (LV) suggests the presence of myocardial perfusion abnormalities.Aim: To determine a relationship between electrophysiological and perfusion abnormalities inLV myocardium in patients with coronary heart disease, post infarction aneurysms and ventricular tachycardia.Materials and methods: We assessed 23 patients with post infarctionLV aneurysms who were candidates for surgical removal of the aneurysm and/or coronary artery bypass grafting. Methods of assessment included intracardiac electrophysiology study (EPS) with a 3D electro-anatomical reconstruction ofLV, as well as perfusional one-photon emission computer tomography of the myocardium with 99mTc-Technetril.Results: In most (68%) ofLV segments with normal electrical conductivity (electric potential magnitude above 1.5 mV, EPS group 1), myocardial perfusion exceeded 70% (accumulation of the radionuclide agent in percentages from maximal myocardial uptake). The transitional zone segments (electric potential magnitude of 0.5–1.5 mV, EPS group 2) comprised equal (18% each) in the zones with low perfusion proportions (31–69% and 45–54%). Most (52%) segments with “electrophysiological scar” (electric potential magnitude below 0.5 мВ, EPS group 3) were in the zone with no perfusion (< 30%). Segments with zero conductivity (EPS group 4) were located also in the zone with no perfusion and partially (20%) in the hypoperfusion (up to 44%) zone. Assessment of perfusion percentage in each individual segment showed that EPS group 1 segments were perfused at 61% (48–71%) of maximal LV myocardial perfusion, EPS group 2 segments, at 45% (34–56%), EPS group 3 segments, at 35% (30–46%), and EPS group 4 segments, at 26% (21–31%). In all patients groups, there was a significant correlation with myocardial perfusion on the semiuantitative scale (i.e., perfusion groups from 0 to 4) (V = 93.5; p < 0,001), as well as negative correlation on the quantitative scale (r = -0,56; p < 0,001), thereby demonstrating that segments with higher perfusion have higher probability to be in EPS group 1.Conclusion: Electrophysiological characteristics ofLV depend on myocardial perfusion. Electrophysiologically normal myocardium with electric potential above 1.5 mV, the transitional zone (0.5–1.5 mV) and the zone with potential of < 0.5 mV differ significantly in their perfusion percentages (61, 45 and 35%, respectively).
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