Breaking the Algorithm: Unearthing Life-Threatening Multivessel Spontaneous Coronary Artery Dissection (SCAD) After a Negative Observation Unit Workup

Figures

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  Figure 1. Computed tomography (CT) of the chest with intravenous contrast. (A) Coronal view demonstrating an enlarged cardiac silhouette with mild bilateral pleural effusions. (B) Sagittal view highlighting the enlarged heart relative to the thoracic cavity. (C) Axial lung window image showing small bilateral pleural effusions without focal consolidation. No evidence of pulmonary embolism was identified.

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  Figure 2. Twelve-lead electrocardiogram obtained one week before presentation demonstrating normal sinus rhythm at 62 beats per minute, with possible inferior and anterior infarct patterns of undetermined age. ST segments are isoelectric without acute elevations or depressions. No dynamic ischemic changes were present compared with subsequent ECGs, which later demonstrated new lateral ST-segment elevations consistent with evolving myocardial ischemia secondary to spontaneous coronary artery dissection (SCAD).

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  Figure 3. Twelve-lead electrocardiogram obtained by EMS demonstrating sinus rhythm at 61 beats per minute (PR 126 ms, QRS 88 ms, and QTc 419 ms), left axis deviation (−65°), and poor R-wave progression across the precordium. Nonspecific ST-T abnormalities are most pronounced in the inferior (III, aVF) and lateral (I, aVL, V5-V6) leads, including 1-2 mm ST-segment depression in leads III and aVF. Findings could be concerning for myocardial ischemia; however, a repeat ECG en route demonstrated a return to normal sinus rhythm. EMS: Emergency medical services; PVCs: Premature ventricular contractions.

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  Figure 4. Twelve-lead electrocardiogram obtained on ED presentation demonstrating normal sinus rhythm at 70 beats per minute with mild ST-segment elevation in the lateral leads (I and aVL) and reciprocal ST-segment depression in the inferior leads (III and aVF). These dynamic changes were new compared with the patient’s ECG obtained one week earlier (Figure 2) and, in the setting of recurrent chest pain, represented a critical decision point prompting repeat echocardiography and urgent cardiology consultation for coronary angiography. Subsequent angiography confirmed spontaneous coronary artery dissection.

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  Figure 5. Coronary angiography demonstrating spontaneous coronary artery dissection (SCAD) of the mid-to-distal right coronary artery. (A) Right anterior oblique view of the left coronary system highlighting the left main coronary artery with luminal irregularity and smooth tapering. (B) Left anterior oblique projection of the right coronary artery confirming long, tubular narrowing consistent with type 2 SCAD. (C, D) Additional projections of the right coronary artery demonstrating the dissected segment extending distally without evidence of atherosclerotic plaque or thrombus. (E) Final frame of the left coronary system highlighting the left main coronary artery with preserved distal perfusion and TIMI 3 flow. SCAD: Spontaneous coronary artery dissection; TIMI: Thrombolysis in myocardial infarction.