title: Simple anatomical basis for surface electrocardiographic changes during selective coronary arteriography.
abstract: The relationship between surface electrocardiographic changes during selective coronary arteriography and coronary artery anatomy was examined in 185 consecutive patients. When both major arteries were patent, two distinct patterns of electrocardiographic changes occurred. Electrocardiogram leads reflecting the areas supplied by the injected vessels showed a change we have termed the 'perfusion response', while electrocardiogram leads reflecting regions not supplied by the injected vessel simultaneously showed a pattern we have termed the 'reciprocal response'. These changes were reproducible on serial injections, and occurred whether or not coronary artery or valvular heart disease was present. A third type of electrocardiographic change--termed a 'biphasic response' and comprising a reciprocal followed by a perfusion response--was observed in leads reflecting a collateral-dependent region of viable myocardium. This response was seen in the inferior surface leads with left coronary artery injection when the right coronary artery was occluded, but not in leads I and aVL with right coronary artery injection when a branch of the left coronary artery was occluded, where chest leads may be needed for its detection. The biphasic response was also seen in the inferior leads with left coronary artery injection in patients in whom this artery was dominant. Thus, the distribution of electrocardiographic changes during arteriography is dependent on native coronary artery anatomy, collateral vessels and myocardial viability. Changes relate to the site of coronary lesions only where vessels are occluded, but may be of practical value when the viability of (and thus suitability for bypass grafting to) a myocardial region is in doubt.
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage*; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000033:anatomy & histology; D004562:Electrocardiography; D006801:Humans; D007269:Injections, Intra-Arterial
chemical_list: D003287:Contrast Media