Disappearance of septal q-wave or appearance of abnormal Q-wave in V5 and V6 after onset of anterior acute myocardial infarction： electrocardiographic and angiographic correlations

BackgroundThefactorsinfluencingtheq-wavechangesinV5andV6duringanterioracutemyocardialinfarction(AMI)havenotbeenthoroughlydescribed.MethodsWestudied70patientswithafirstanteriorAMI,inwhomtheelectrocardiogram(ECG)showedeitherdisappearanceofthenormalseptalqwave(n=24)orpresenceofpathologicalQwaveinV5andV6(n=46)duringfollow-up.TheECGandcoronaryangiographyfindingswerecorrelated.ResultsTherewasnodifferencebetweenthe2groupsintheculpritsiteproximaltoS1(46%vs.36%,P=0.405),buttheculpritsitewasmorefrequentlylocatedproximaltoD1inthegroupwithabnormalQwave(21%vs.67%,P=0.001).Patientswithdisappearanceoftheseptalqwavemoreoftenhadalargeobtusemarginalbranch(46%vs.22%,P=0.037)anddisappearanceoftherwaveinV1(88%vs.7%,P=0.001).PatientswithabnormalQ-wavemoreoftenhadalargeLAD(42%vs.71%),smallrwaveortallorwideRwaveinV1(0%vs.89%,P=0.001)andabnormalQwavesintheinferiorleads(33%vs.59%,P=0.044).ConclusionsInpatientswithfirstanteriorAMI,qwavechangesinV5andV6correlatedwiththemorphologyinV1.EmergingabnormalQwaveinV5/V6predictedtheculpritlesioninalargeLADproximaltoD1,butdisappearanceoftheseptalqwavecouldnotpredicttheculpritlesionproximaltoS1.