Emergent Care / Stabilization:
Airway, breathing, and circulation (ABCs), obtain and interpret 12-lead ECG within 10 minutes of arrival to identify a STEMI and need for emergent revascularization, establish intravenous (IV) access, place patient on cardiac monitor with continuous pulse oximetry, have resuscitation equipment available, consider serial ECGs, obtain troponin, aspirin load if no contraindications, and nitroglycerin, oxygen, and analgesia as indicated.

Diagnosis Overview:
A ventricular aneurysm is a weakening of the ventricular wall that occurs after a myocardial infarction (MI). The damaged myocardium is replaced with fibrous tissue, which cannot contract. The replacement fibrous tissue then bulges outward during systole, appearing as an aneurysm.

Ventricular aneurysm occurs after transmural MI and is not uncommon, occurring in as many as 35% of large MIs. Total occlusion of the left anterior descending coronary artery is the largest risk factor, although failure to open any occluded coronary artery can lead to a ventricular aneurysm. The prevalence of ventricular aneurysm has decreased since the routine use of acute revascularization for MI, but a prolonged time to percutaneous cardiac intervention (PCI) can increase the risk.

Ventricular aneurysms can be true or false aneurysms. True aneurysms involve the full thickness bulging of the ventricular wall and contain 3 layers, which are the endocardium, the thin myocardium, and the epicardium. True ventricular aneurysms are almost always a result of transmural MI. Most true aneurysms occur at the apical or anteroseptal wall about 85% of the time.

False aneurysms are actually caused by ventricular wall rupture, but patient death is prevented by sealing the rupture by hematoma, thrombus, or pericardium. There is no ventricular tissue in a false aneurysm, or "pseudoaneurysm." These tend to occur on the posterior and lateral wall segments. False aneurysms are most commonly caused by transmural MI, but can also be caused by trauma, cardiac surgery, or infection (endocarditis).

True and false ventricular aneurysms both can rupture, causing death, and they are life-threatening emergencies. False aneurysms are more likely to rupture than true aneurysms.