A 42 year old man presents following an episode of rapid and regular palpitations for about 30 minutes. He also felt faintish and "close to death". There was no chest pain. The paramedical team obtained an abnormal ECG and performed electrical cardioversion. His medical, drug and family histories are unremarkable. A FBC, electrolytes, renal and liver functions and thyroid profile are normal.
The ECG obtained en-route to the hospital shows a broad complex tachycardia with fusion beats and capture beats.
The resting ECG shows downsloping ST-segment elevations and T inversions in the leads V1 to V3.
Troponin-I: 1.0 ng/l (normal < 0.4 ng/l) CPK-MB: 150 IU/l (normal < 5 IU/l)
No structural or valvular defects are noted and no wall motion abnormalities are present. The coronary artery origins are normal. The left ventricular ejection fraction is 64%