POSTINFARCTION VENTRICULAR ANEURYSMS

Ventricular aneurysms are circumscribed, thin-walled fibrous, noncontr actile outpouchings of the ventricle. The majority are apically locate d, true aneurysms of the left ventricle (LV) that occur as a consequen ce of transmural myocardial infarction (MI). The precursor of aneurysm formation appears to be infarct expansion early after acute MI and oc currence generally relates to infarct size. The presence of underlying hypertension and the use of steroids and nonsteroidal anti-inflammato ry agents may promote aneurysm formation. The clinical sequelae includ e congestive heart failure (CHF), thromboembolism, angina pectoris, an d ventricular tachyarrhythmias. Late rupture is a particular complicat ion of false aneurysms in which the pericardium is the aneurysm wall. The diagnosis may be suspected by the clinical finding of a diffuse, p ansystolic apical thrust, persistent ST-segment elevation on the elect rocardiogram, and distortion of the cardiac silhouette on chest x-ray. This can be confirmed using echocardiography, radionuclide ventliculo graphy, and cardiac catheterization, The latter has the additional adv antage of being able to delineate the coronary anatomy, Management inv olves prevention, specific therapy for the various clinical manifestat ions, and surgery. Therapeutic interventions with thrombolytic agents, aspirin, heparin, and beta blockers that are applied early in the evo lution of an MI may limit infarction size, thereby reducing the tenden cy toward infarct expansion and aneurysm formation. Patients with mild CHF can usually be controlled with the standard combination of angiot ensin-converting enzyme inhibitors, diuretics, and digoxin. Thromboemb olism is best prevented by anticoagulation with warfarin for at least 3 months after the acute MI. The choice of pharmacotherapy for ventric ular tachyarrhythmias should be guided by electro-physiologic studies, The treatment of patients with angina pectoris utilizes conventional therapeutic modalities. Refractory angina and high-risk coronary anato mic subsets have replaced CHF as the commonest indications for surgica l intervention in recent studies. In these patients, aneurysmectomy is often performed as an aside to the primary revascularization procedur e. Although aneurysmectomy may improve the functional status and eject ion fraction of some patients with CHF, its effect on prognosis is les s certain. The prognostic advantage of surgery appears to be related m ore to coronary revascularization than to the aneurysm resection per s e.