Recurrent polymorphic ventricular tachycardia without chest pain: an unusual presentation of focal coronary artery spasm.

Coronary artery spasm (CAS), or Prinzmetal angina, is a recognised cause of myocardial ischaemia in non-obstructed coronary arteries which typically presents with anginal chest pain. This case report describes an atypical presentation of CAS in a 68-year-old white British male with cardiovascular risk factors. The patient presented with recurrent palpitations and pre-syncope, with no chest pain. Ambulatory electrocardiography (ECG) monitoring revealed recurrent polymorphic ventricular tachycardia (PMVT). Coronary angiography identified moderate stenosis of the right coronary artery (RCA), without significant flow restriction by invasive pressure wire interrogation. Inpatient monitoring revealed episodes of recurrent PMVT coinciding with transient inferior ST elevation and a distinct 'shark fin' waveform, indicating dynamic RCA occlusion. The arrhythmias persisted despite initial medical management, including calcium channel blockers and intravenous glyceryl trinitrate. Percutaneous coronary intervention to the moderate RCA lesion was performed, which definitively treated the arrhythmias. This case emphasises the importance of recognising plaque-associated CAS as a potential trigger for life-threatening arrhythmias, even in the absence of chest pain. While medical therapy remains first-line treatment, life-threatening presentations may necessitate invasive interventions to stabilise the patient and prevent recurrence.