86 year-old woman with two hours of dull chest pain and dizziness. Ex-smoker with hypertension and dyslipidaemia.
ETA 20 minutes.
Inferolateral STEMI complicated by junctional bradycardia
- ST elevation inferolaterally in leads II, III, aVF and V4-V6
- Reciprocal ST depression in aVR, aVL and V2
- Hyperacute T-waves seen inferiorly
- Junctional bradycardia with a heart rate of 42 beat per minute
The presence of widespread inferolateral ST elevation indicates a large territory right coronary artery infarct affecting the inferior and lateral walls.
Junctional bradycardia is likely due to a combination of:
- Sinus node dysfunction from ischaemia of the sinoatrial node artery, which arises from the proximal RCA in 60% of people
- Vagal effects of an inferior STEMI (the bezold-jarisch reflex)
The extent of the ST changes and the presence of junctional bradycardia hints at a more proximal RCA occlusion and a higher risk case.
Note that the terms junctional bradycardia and junctional escape rhythm are synonymous, simply referring to an escape rhythm arising at the AV node. Because the rate of spontaneous depolarisation at the level of the AV node is usually 40-60 bpm, this is often a bradyarrhythmia.
Proximal right coronary artery (RCA) occlusion with thrombus.
- Left Main Coronary Artery — normal
- Left Anterior Descending Coronary Artery — mild coronary artery disease
- Left Circumflex Coronary Artery — normal
- Right Coronary Artery — proximal occlusion with thrombus
Proximal RCA occlusion with thrombus
Proceed to percutaneous coronary intervention of proximal RCA.
- Dual antiplatelet therapy for 12 months. Lifelong aspirin
- Aggressive cardiovascular risk factor management
- Admit to CCU
- Wiesbauer F, Kühn P. ECG Mastery: Yellow Belt online course. Understand ECG basics. Medmastery
- Wiesbauer F, Kühn P. ECG Mastery: Blue Belt online course: Become an ECG expert. Medmastery
- Kühn P, Houghton A. ECG Mastery: Black Belt Workshop. Advanced ECG interpretation. Medmastery
- Rawshani A. Clinical ECG Interpretation ECG Waves
- Smith SW. Dr Smith’s ECG blog.
ACTIVATE or WAIT
MBBS (Hons), BMSci (Hons). Cardiology Registrar at Royal Perth Hospital in Perth, Australia. Graduate of The University of Western Australia in 2016 with Honours and completed Basic Physician Training with the RACP in 2021. Passion lie in cardiac imaging and electrophysiology.