Natural History ofLeftVentricular Sizeand Function After AcuteMyocardial Infarction Assessment andPrediction byEchocardiographic Endocardial Surface Mapping

Toinvestigate thenatural history ofregional dyssynergy andleftventricular sizeafter myocardial infarction, 57patients witha first Q wave myocardial infarction (18anterior, 35 inferior, andfourapical byechocardiography) werestudied bytwo-dimensional echocardiographyandcompared with30control patients. Measurements fromtheechocardiograms were usedtoconstruct maps oftheleft ventricular endocardial surface fromwhichtheendocardial surface areaindex(ESAi) andthepercent oftheendocardial surface areainvolved byabnormal wallmotion(%AvAWM) were calculated. Themaps fromentry and3-monthechocardiograms were usedtoclassify patients basedon changes inESAiandabnormalwallmotion. Two subgroups ofpatients wereidentified atentry -thosewitha normalESAi(group 1,n=50)and those withan increased ESAi(group 2,n=7).Group1patients was subdivided at3monthsby changes occurring inESAi(LA, 5%increase [n=191; 1B,no change[n=23]; 1C,5%decrease [n=8]). Theincrease inESAi(64.9±5.2 to75.4±7.5 cm2/m2, p<0.0001) ingroup 1Awas associated withglobal ventricular dilatation (n=11)andclinically silent infarct extension (n=8).Groups1Band1Cwerecomposed predominantly ofpatients withinferior infarctions, andallexhibited either no change ora significant decrease ininfarct size(infarct regression). Group2 patients demonstrated a continued increase inESAiby3 months(88.2±10.0 to 101.4± 15.5cm2/m2, p<0.007). Thisgroupcomprised onlypatients withanterior infarctions, andallexhibited infarct expansion attheleft ventricular apex.Thechanges inleft ventricular size andfunctional infarct size areheterogeneous after acutemyocardial infarction andrelate totheinitial endocardial surface area,infarct location, andfunctional infarct size. (Circulation 1990;82:484-494)