Diagnosis of multiple infarcts from complex electrocardiograms during normal rhythm, left XXXX , and ventricular pacing.

@entity1 @entity583 @entity63 @entity5036 @entity453 @entity26128
INTRODUCTION: Because of better treatment of chronic @entity453 , @entity1 with multiple @entity63 insults are living longer and requiring long-term management. Electrocardiograms (ECGs) in @entity1 with multiple @entity583 (MMIs) are a challenge to the clinician or cardiologist. This is because second @entity583 ( @entity583 ) often modify or obscure the ECG effects of the first MI and vice versa. This can result in complex tracings, which are difficult to interpret and predict the locations of damaged regions. It is important to identify MMI because, additively, they can result in poor ventricular function. METHODS: New criteria for the diagnosis of MMI were derived from studies in which ECGs and body surface potential distribution maps were correlated with @entity26128 in animal studies of MI and in @entity1 at the time of coronary artery bypass graft and with the pathologic anatomy in a few @entity1 . The initial criteria were fine tuned by correlations between ECGs and independent data obtained from catheterization and other imaging modalities (ultrasound and radionuclide single photon emission computed tomography). RESULTS: Often 2 or more @entity583 are concealed according to classical Q- and R-wave criteria. @entity583 located in opposing walls (180  ), that is, inferior-superior, anterior-posterior, are the most difficult to identify. Two @entity583 that are not opposing (90  ) are usually readily detectable. The pathologic Q waves produced by each separate MI, when opposing, are replaced by multiple QRS deflections or baseline crossings, which are referred to as M and W complexes. These waveforms replace Q waves and are equally weighted in a scoring system to improve diagnostic accuracy of ECG interpretation. These new criteria can also be used to predict @entity583 in left @entity5036 , intraventricular conduction delay, and ventricular pacing. CONCLUSION: Multiple @entity583 modify the ECG because they eliminate Q waves and result in confusing, splintered QRS waveforms, referred to as M and W complexes. New criteria are presented to diagnose the presence and locations of these MMIs, which predict reduced left ventricular function, in normal sinus rhythm, left @entity5036 , and ventricular pacing.
