An interesting ECG case -inferior STEMI with RV involvement
STEMI in a young smoker
Male, aged 32, smoker for 10 years
Severe chest pain of sudden onset, radiating to the left arm and jaw, associated with dizziness
Blood pressure: 90/50 mmHg, heart rate: 82 bpm, respiratory rate: 18 breaths per minute, oxygen saturation: 98% on room air
Jugular venous pressure to angle of jaw, lungs clear
ECG:
SOURCE: https://litfl.com/right-ventricular-infarction-ecg-library/ (Example 2)
Let’s walk through this ECG together:
First degree AV Block
Isoelectric ST segment in V1 with marked ST depression in V2
ST elevation in III > II, in keeping with inferior STEMI
Diagnosis RV infarction confirmed by ST elevation in the right-sided leads (V4R)
Presentation and hemodynamics:
The blood pressure is low
No hypoxia, chest clear
Elevated venous pressure
Clinical Significance of RV Infarction:
RV infarction complicates up to 40% of inferior STEMIs (isolated RV infarction is extremely uncommon)
These patients are very preload sensitive (due to poor RV contractility)
Nitrate may provoke severe hypotension
Hypotension in RV infarction is treated with fluid loading
STEMI under the age of 45 years accounts for 6% to 10% of all myocardial infarctions.
Smoking is the most prevalent modifiable risk factor in 30–49-year-old STEMI patients (74% vs. hypertension 15%, hyperlipidemia 10% and diabetes 7%).
Smoking is a significant risk factor for the development of STEMI by:
Promoting formation of fatty plaques in coronary arteries
Increasing platelet aggregation and coronary blood clot formation
Reducing oxygen-carrying capacity of red blood cells, thereby increasing myocardial ischemia
Causes vasoconstriction, impairing endothelial function, reducing blood flow to the heart
One more consideration in the young:
Consider recent use of cocaine in young STEMI patients. Beta-blockers should not be administered to patients with STEMI precipitated by cocaine use because of the risk of exacerbating coronary spasm.
