Vectorcardiographic criteria for acute right ventricular infarction

Based on serial vectorcardiographic and cardiac scintigraphicstudies of 62 patients with acute myocardial infarction, wepropose vectorcardiographic criteria for the diagnosis of acuteright ventricular infarction. These criteria are: (1) the directionof the maximal spatial ST vector points either to the right-anterior-inferioror to the right-posterior–inferior octant, and (2) themagnitude of the projection of the maximal spatial ST vectoris 0.15 mV in the horizontal plane. By using these criteriacorrelated with scintigraphic results, 92% sensitivity was achievedtogether with 98% specificity; the Kappa statistic was 0.90.In patients with acute inferior and right ventricular infarction,the serial maximal spatial ST vector swung to-and-fro like a‘tug of war’ between right-anterior-inferior andright-posterior-inferior octants during the acute stage. Inpatients with acute inferior-posterior and right ventricularinfarction, the serial maximal spatial ST vector pointed tothe right-posterior-inferior octant during the whole courseof the acute stage. Failure to recognize this electrical phenomenonmay make the clinician inaccurate when judging the clinicalcourse of acute right ventricular infarction or over-estimatethe result of therapeutic intervention.