Advertisement

A woman with dizziness, headache and epigastric discomfort

Published:August 18, 2016DOI:https://doi.org/10.1016/j.ejim.2016.08.011

      1. Indication

      A woman in her 70s presented to the emergency department with 4 h of dizziness, headache and epigastric discomfort. Her only medical history was hypertension. The blood pressure was 89/45 mm Hg, pulse 58 beats per minute, oxygen saturation 98% in ambient air. Electrocardiogram (ECG) showed sinus bradycardia and non-specific ST-T abnormality. Initial troponin was not elevated. Contrast computed tomography (CT) of the aorta was performed to exclude dissection (Fig. 1).
      Fig. 1
      Fig. 1Contrast CT of the aorta at the level of the ventricles showing the inferior part of RV (1), LV (2), coronary sinus (3), inferior vena cava (4) and descending thoracic aorta (5). The coronary sinus is dilated. An area of transmural hypoenhancement is evident along the inferior septal and inferior LV wall, with preserved wall thickness (arrowheads).
      What is the diagnosis?

      2. Diagnosis

      Right ventricular (RV) and left ventricular (LV) inferior wall infarction. The figure shows a cross-section of the ventricles, including part of the coronary sinus, inferior vena cava and descending thoracic aorta. The RV is enlarged. The inferior vena cava size is comparable to that of the aorta, and the coronary sinus appears prominent, arguing against hypovolemia. However, the patient was in shock and bradycardiac. Notably, an area of transmural hypoenhancement is present along the inferior septal and inferior LV wall that has preserved wall thickness, compatible with an acute myocardial infarction. Together with a dilated RV, proximal right coronary artery thrombosis was suspected. Indeed, a subsequent ECG demonstrated inferior ST-segment elevation, and the patient received intravenous thrombolysis.
      RV infarction often results in hypotension and bradycardia. However, the initial ECG may be non-diagnostic. Though not gated to the cardiac cycle, contrast CT of the aorta can detect areas of myocardial perfusion defect of the LV [
      • Lo S.
      • Kwok W.K.
      Acute myocardial infarction found by multi-detector computed tomography ordered for suspected aortic dissection.
      ,
      • Ching S.
      • Chung T.S.
      Myocardial hypoperfusion on conventional contrast computed tomography.
      ], because the scan is timed at maximal aortic opacification that coincides with early contrast passage through the coronaries. Perfusion cannot be assessed on the thin-walled RV, but infarction can be inferred from RV dilation, distended veins, concurrent LV inferior wall defect, and absence of pulmonary embolism.

      Conflict of interests

      We report no conflict of interests regarding this work.

      References

        • Lo S.
        • Kwok W.K.
        Acute myocardial infarction found by multi-detector computed tomography ordered for suspected aortic dissection.
        Hong Kong Med J. 2008; 14: 233-235
        • Ching S.
        • Chung T.S.
        Myocardial hypoperfusion on conventional contrast computed tomography.
        Am J Emerg Med. 2015; 33: 1538.e1531-1538.e1534