A rare case of silent transmural myocardial infarction with diffuse ST elevations complicated by concomitant severe hyperkalemia

Differential diagnosis of the association of gastrointestinal symptoms and ST segment elevation, in the absence of chest pain

This is a review of the underlying causes of the association of ST segment elevation and gastrointestinal symptoms such as abdominal pain, nausea, vomiting, and anorexia, in patients who do not have chest pain. The review was based on anecdotal reports in Googlescholar and Pubmed using the search terms, abdominal pain, nausea, vomiting, anorexia, ST elevation, myocardial infarction, and Takotsubo cardiomyopathy. Those patients who did not have acute myocardial infarction as the cause of the association of ST segment elevation and gastrointestinal symptoms were compared with counterparts with similar symptoms who had well authenticated acute myocardial infarction or Takotsubo cardiomyopathy as the underlying cause of ST segment elevation. The underlying causes of gastrointestinal symptoms which could be associated with ST segment elevation in the absence of either acute myocardial infarction or Takotsubo cardiomyopathy comprised pneumonia, pulmonary embolism, perforated gastric ulcer, intestinal obstruction, acute appendicitis, acute pancreatitis, acute cholecystitis, pheochromocytoma, bacterial meningitis, diabetic keto acidosis, and cannabis abuse. However, each of those disorders could also coexist either with acute myocardial infarction or with Takotsubo cardiomyopathy. The coexistence of ST segment elevation and gastrointestinal symptoms(without chest pain) was also documented in patients with esophageal perforation, mesenteric ischaemia, aortic dissection, Kounis syndrome, and in electrolyte disorders. In the context of presentation with gastroenterological symptoms but without concurrent chest pain, echocardiography appeared to be useful in distinguishing between "pseudo" myocardial infarction characterised by ST segment elevation in the absence of cardiac disease vs ST segment elevation attributable either to acute myocardial infarction or to Takotsubo cardiomyopathy.

Asymptomatic ST elevation myocardial infarction

BACKGROUND

A 71-year-old non-smoking female with a history of diabetes, hypertension, hyperlipidemia and end-stage renal disease presented to the emergency department for right leg pain due to an ankle fracture.

CASE

The patient's initial electrocardiogram (ECG) revealed ST segment elevations in the anterior leads. She denied any chest pain, shortness of breath, fatigue, lightheadedness, palpitations, nausea or diaphoresis. Her initial laboratory Troponin I resulted 35.9 ng/mL. Coronary catheterization demonstrated 99% occlusion of the left anterior descending (LAD) coronary artery. The patient had 2 drug eluting stents placed in the LAD with 10% residual stenosis.

CONCLUSION

Although witnessing an ongoing asymptomatic ST elevation myocardial infarction (STEMI) is rare, this case highlights the importance of early revascularization when the ECG demonstrates a STEMI, even in the absence of symptoms for patients at risk for silent myocardial infarctions.