ST-segment elevation myocardial infarction mimics: The differential diagnosis of nonacute coronary syndrome causes of ST-segment/T-wave abnormalities in the chest pain patient

Figures

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  Figure 1. Electrocardiographic causes of ST segment elevation in adult chest pain patients in the prehospital and emergency department settings. EMS: Emergency medical service, ED: Emergency department, LVH: Left ventricular hypertrophy, LBBB: Left bundle branch block, STEMI: ST-segment elevation myocardial infarction, BER: Benign early repolarization, RBBB: Right bundle branch block, NSIVCD: Nonspecific intraventricular conduction delay[9]

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  Figure 2. Electrocardiogram (ECG) abnormalities in the ST-segment elevation myocardial infarction (STEMI) patient. (a) Convex ST-segment elevation morphology, very common in the acute myocardial infarction (AMI) patient, (b) Obliquely straight ST-segment elevation morphology, very common in the AMI patient, (c) Concave ST-segment elevation morphology, frequently seen early in the course of the acute infarction; this ST-segment elevation morphology, however, is much less common later in course of the AMI patient, (d) The hyperacute T wave of early STEMI, usually seen in the initial 5–30 min of STEMI; with the appropriate clinical presentation, the hyperacute T wave is considered a STEMI equivalent, (e) Reciprocal ST-segment depression, more commonly known as reciprocal change, is defined as ST-segment depression on the ECG of a patient with simultaneous ST-segment elevation. Its presence, in a patient with the appropriate clinical presentation, is strongly suggestive of STEMI. Note that the concept of reciprocal change cannot be used in the setting of left bundle branch block, right ventricular paced pattern, and the left ventricular hypertrophy via voltage pattern– the ST-segment…

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  Figure 3. The ST-segment and T-wave abnormalities seen in left ventricular hypertrophy pattern (LVH) via voltage. Note that the ST-segment and T-wave abnormalities seen in LVH via voltage are seen in approximately 80% of patients with this pattern and are referred to as the strain pattern. (a) Asymmetric, down sloping ST-segment depression, fusing with an inverted T wave in lead I, (b) Asymmetric, down sloping ST-segment depression, fusing with an inverted T wave in lead V6, (c) Concave morphology ST-segment elevation in the LVH patient, commonly seen in leads V1–V4. Note ST-segment–T wave complex is directed opposite the primary direction of the QRS complex. Note that the ST-segment–T-wave complex is directed opposite the primary direction of the QRS complex. It is important to note that the modified Sgarbossa criteria is not applicable in the LVH with strain pattern. Yet, the anticipated relationship of the ST segment and T wave is directed opposite of the primary polarity of the QRS complex

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  Figure 4. A comparison of the elevated ST segment in left ventricular hypertrophy (LVH) and ST-segment elevation myocardial infarction (STEMI). Note the concave morphology of the elevated ST segment in LVH as compared to STEMI with the convex and obliquely straight morphologies of ST-segment elevation. Furthermore, note the large amplitude of the negatively oriented QRS complex in the LVH patient. STEMI: ST-segment elevation myocardial infarction

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  Figure 5. The anticipated electrocardiogram findings in the patient with uncomplicated left bundle branch block (LBBB). In general, the anticipated findings in LBBB are described as follows: The ST segment–T wave complex is directed opposite (i.e., discordant) to the primary direction of the QRS complex. (a) Discordant ST-segment elevation with upright T wave, (b) Discordant ST-segment depression with inverted T wave

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  Figure 6. A comparison of the elevated ST segment in left bundle branch block (LBBB) and ST-segment elevation myocardial infarction (STEMI). Note the concave morphology of the elevated ST segment in LBBB as compared to STEMI with the convex and obliquely straight morphologies of ST-segment elevation. In addition, note the widened QRS complex, typical of bundle branch block. STEMI: ST-segment elevation myocardial infarction

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  Figure 7. The anticipated electrocardiogram findings in the patient with uncomplicated right ventricular paced pattern. In general, the anticipated findings in right ventricular paced pattern are described as follows: The ST-segment–T wave complex is directed opposite (i.e., discordant) to the primary direction of the QRS complex. (a) Discordant ST-segment depression with inverted T wave, (b) Discordant ST-segment elevation with upright T wave. In both “A” and “B,” note the widened QRS complex and pacer spike

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  Figure 8. A comparison of the elevated ST segment in right ventricular paced pattern and ST-segment elevation myocardial infarction (STEMI). Note the concave morphology of the elevated ST segment in right ventricular paced pattern as compared to STEMI with the convex and obliquely straight morphologies of ST-segment elevation. In addition, note the widened QRS complex, typical of a right ventricular paced pattern as well as the pacing spike, immediately prior to the QRS complex. STEMI: ST-segment elevation myocardial infarction

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  Figure 9. Electrocardiogram findings of benign early repolarization. (a) Concave morphology ST-segment elevation. In both examples, it appears that the ST segment has been lifted evenly off the baseline at the J point, with preservation of the concave ST segment, (b) Concave morphology ST segment. Also note irregularity of the J point, a finding which is strongly suggestive of benign early repolarization, (c) Prominent T wave and concave morphology ST segment; T waves can be very prominent, particularly in leads V2–V4. J point irregularity is also noted

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  Figure 10. A comparison of the elevated ST segment in benign early repolarization (BER) and ST-segment elevation myocardial infarction (STEMI). Note the concave morphology of the elevated ST segment in BER as compared to STEMI with the convex and obliquely straight morphologies of ST-segment elevation. STEMI: ST-segment elevation myocardial infarction

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  Figure 11. Electrocardiogram abnormalities encountered in some patients with acute myocarditis/myopericarditis. (a) ST-segment elevation with PR segment depression, (b) Pronounced ST-segment elevation with subtle PR segment depression, (c) Spodick’s sign, down sloping TP segment, seen in some patients with acute myopericarditis

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  Figure 12. A comparison of the elevated ST-segment in acute myocarditis/myopericarditis and ST-segment elevation myocardial infarction (STEMI). Note the concave morphology of the elevated ST segment in myocarditis as compared to STEMI with the convex and obliquely straight morphologies of ST-segment elevation. In addition, note the PR segment depression in myopericarditis. STEMI: ST-segment elevation myocardial infarction