CASE REPORT
A 48-year old Caucasian male presented to our hospital following a witnessed out-of-hospital cardiac arrest. Bystander cardiopulmonary resuscitation (CPR) was initiated swiftly. On arrival of the ambulance crew the initial arrest rhythm was found to be ventricular fibrillation VF for which he received CPR with two DC shocks. Return of spontaneous circulation (ROSC) was established within ten minutes of the initial collapse. The post-ROSC ECG showed ST segment elevation in leads II, III and aVF (see figure 1), in keeping with a right coronary artery occlusion. The patient was intubated on scene and brought immediately to the William Harvey Hospital with a view to primary percutaneous coronary intervention (pPCI).
Figure 1. Presentation ECG showing Inferior STEMI
Collateral history revealed that the patient had experienced several episodes of left-sided chest and shoulder pain in the preceding two days. These episodes were not associated with physical exertion and had been attributed by the patient to work-related stress. On further questioning it transpired that two years previously, the patient had presented to the emergency department with chest, arm and shoulder pain following a one-week history of diarrhoea, fever and night sweats. ECG had shown mild ST segment elevation in leads V2-V5 associated with a significant troponin rise leading to an initial diagnosis of Non-ST Elevation Myocardial Infarction (NSTEMI). Coronary angiography had subsequently been normal. Echocardiography had showed a left ventricular ejection fraction of 35-40 per cent with an 0.7cm pericardial effusion and mild hypokinesia of the septum and anterior wall. He had been given a diagnosis of viral myopericarditis and discharged home on Ramipril. Repeat echocardiography some months later had shown resolution of the pericardial effusion, improved ejection fraction of 55-60 per cent and residual mild anteroseptal and apical hypokinesia. He had subsequently returned to work, suffering no further symptoms.
On arrival at the emergency department, the initial inferior ST segment elevation reported on the post-ROSC ECG had resolved. Bedside echocardiography revealed mild infero-basal hypokinesia with a left ventricular ejection fraction of 55 per cent. The patient was immediately transferred to the cardiac catheter suite where, once again, coronary angiography showed no clinically significant disease in the major coronary arteries (see figure 2).