Incidental Electrocardiographic Recognition of Left Anterior Fascicular Block With Delayed Troponin Elevation: A Case Report With Clinical Correlation

Figures

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  Figure 1. Initial ECG obtained within 10 minutes of emergency department presentation. Initial ECG obtained within 10 minutes of emergency department presentation, showing sinus rhythm with left axis deviation, most consistent with left anterior fascicular block, without acute ST-segment elevation. Subtle T-wave flattening is noted in the lateral leads, especially V5-V6.

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  Figure 2. Repeat ECG obtained 1 hour after presentation showing sinus rhythm. Repeat ECG obtained 1 hour after presentation showing sinus rhythm with persistent left axis deviation, likely related to left anterior fascicular block. No acute ST-segment elevation or pathological Q-waves are seen. Mild nonspecific ST-T changes, including T-wave flattening, remain present.

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  Figure 3. ECG obtained in the cardiac care unit 24 hours after admission. ECG obtained in the cardiac care unit 24 hours after admission, showing sinus rhythm with left axis deviation, likely due to left anterior fascicular block, with mild nonspecific ST-T changes and no acute pathological ischemic change.

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  Figure 4. ECG obtained 48 hours after admission during recurrent chest pain. ECG obtained 48 hours after admission during recurrent chest pain, showing new inferolateral T-wave inversions involving leads II, III, aVF, and V4-V6, associated with delayed troponin T elevation and consistent with evolving myocardial ischemia.

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  Figure 5. Coronary angiography showing almost 90% stenosis of the proximal right coronary artery.

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  Figure 6. Coronary angiography showing a severe lesion (80-90%) in the mid left circumflex artery.