A 77-year-old lady who normally keeps fit and well first developed chest discomfort at rest several days ago. This resolved spontaneously and she presumed it to be indigestion. This morning, she was aware of a discomfort in her central chest on awakening. While showering an hour later, the discomfort intensified and was now quite painful. She described it as being heavy in nature. She was aware of it radiating to both upper arms and through to her back. She also described a ‘fluttering’ in her chest and an awareness of her own heartbeat.
These symptoms were still present an hour later and she called her GP practice. An ambulance was mobilised. As part of the crew's assessment, the 12-lead electrocardiogram (ECG) in Figure 1 below was recorded.
What does the ECG show?
Interpretation of the ECG rhythm
This rhythm is atrial fibrillation (AF). AF is the most common sustained abnormal heart rhythm (arrhythmia) that health professionals will encounter (National Institute for Health and Care Excellence (NICE), 2014). It is typically detected as irregular pulse or an irregular rhythm on an ECG (NICE, 2021).
Interpretation of the 12-lead ECG
A finding of ST depression in V1–V4 in patients with acute ischaemic sounding chest pain should always alert the paramedic to the likelihood of this being a posterior myocardial infarction. This is the commonest of the occlusive myocardial infarction (OMI) findings where the ECG does meet the standard ST elevation criteria that would normally trigger transfer for primary percutaneous coronary intervention (PPCI).
In this case, the local cardiac catheterisation laboratory (cath lab) was alerted and she was accepted for PPCI. Coronary angiography was undertaken via the right radial artery and a completely occluded proximal circumflex coronary artery was identified. A single drug-elution stent was inserted.
She remained stable in the coronary care unit (CCU) until her discharge home 3 days later.