A 70 year old female was referred for a rescue percutaneous coronary intervention (PCI) after she was thrombolysed for a lateral ST segment elevation myocardial infarction (STEMI). She was commenced on ionotropes for hypotension. A coronary angiogram revealed an occluded circumflex distally. The degree of hypotension was out of keeping with the region of infarct and therefore a left ventriculogram was performed which demonstrated a ventricular septal rupture. In patients with a STEMI a quick physical exam should proceed cardiac catheterisation to rule out any pathological murmurs. A mechanical problem should be suspected in STEMI patients where the degree of shock is out of keeping with the infarct.