Left Ventricular Aneurysm

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• True aneurysm:

  • – Echocardiographic evidence of thinned, scarred myocardium that deforms the diastolic silhouette of the left ventricle with systolic akinesis or dyskinesis

• False aneurysm:

  • – Echocardiographic evidence of a thin-walled sac communicating with an infarcted segment of the left ventricle by a narrow neck

  • – Systolic expansion of the sac is often observed

  • – Color-flow imaging shows flow in and out of the sac

GENERAL CONSIDERATIONS

• True left ventricular (LV) aneurysms develop in less than 5% of all patients with acute myocardial infarction (MI)

• Intraventricular pressure stretches the infarcted noncontractile segment, leading to aneurysm formation

• Over time, dense fibrous tissue replaces infarcted myocardium, but systolic expansion of the segment can be visualized on echocardiogram

• Aneurysms are more likely to occur after an anterior MI, particularly at the apex

• Rupture is rare, unlike in pseudoaneurysm

• High incidence of ventricular arrhythmias is major cause of increased mortality

• Calcification of the scar may occur eventually and may be visible on chest x-ray

• Thrombus formation in the aneurysm is common

• In pseudoaneurysm, the wall is made up of thrombus and pericardium, and the risk of rupture is high

• LV aneurysm can occur in nonischemic heart diseases such as Chagas’ disease and hypertrophic cardiomyopathy

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Dyspnea secondary to LV dysfunction

• Chest pain may be present if there is associated pericarditis

PHYSICAL EXAM FINDINGS

• Enlarged and sustained precordial impulse

• Third or fourth heart sounds

DIFFERENTIAL DIAGNOSIS

• Akinetic or dyskinetic segments without diastolic deformity

• Pericardial cyst or loculated effusion

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC, brain natriuretic peptide test, troponin

ELECTROCARDIOGRAPHY

• ECG: persistent ST elevation with Q waves most common

IMAGING STUDIES

• Echocardiogram shows:

  • – Systolic expansion of a thin-walled segment of the LV and often the presence of thrombus (laminated or fresh)

  • – The size of the neck of the aneurysm compared with the fundus of the LV is useful for distinguishing true aneurysm from pseudoaneurysm

  • – In pseudoaneurysm, the neck is small (< 50% of diameter of fundus)

• Cardiac MRI can also be used to identify LV aneurysms and may be useful if echocardiography is not diagnostic

DIAGNOSTIC PROCEDURES

• Left ventriculography can also demonstrate aneurysms and should be done if coronary angiography is done

TREATMENT

CARDIOLOGY REFERRAL

• Heart failure

• Ventricular arrhythmias

• Persistent angina

• Systemic emboli or visible thrombus

HOSPITALIZATION CRITERIA

• Pulmonary edema

• Unstable angina

• Symptomatic ventricular arrhythmias

• Stroke ...