Early detection and management of left ventricular free wall rupture during acute myocardial infarction

Ventricular free wall rupture following acute myocardial infarction

SUMMARY

Ventricular free wall rupture remains a dreaded complication of acute myocardial infarction. A dramatic fatal presentation is not universal and if recognized early, especially in its sub-acute form, a therapeutic intervention may be lifesaving. Changing trends in its natural history and the previously described pathological subtypes have emerged since the advent of thrombolysis. Although frequently unpredictable, certain clinical, echocardiographic and electrocardiographic signs should suggest the diagnosis. Moreover, knowledge of predisposing risk factors and a high index of suspicion are helpful in early recognition of this complication. In recent years, several different therapeutic approaches have been described including percutaneous seals and surgical mechanical closure of ventricular free wall rupture. In this review, we sought to highlight established and debatable aspects of this pathology to hopefully enhance prompt diagnosis and treatment by all clinicians caring for patients suffering acute myocardial infarction.

Ventricular free wall rupture in acute myocardial infarction

Despite a progressive reduction in acute myocardial infarction mortality over the years, death related to ventricular free wall rupture has not changed. This is mostly related to the catastrophic presentation and death within minutes in the majority of these patients. Once rupture is suspected, bedside echocardiography should be performed immediately, followed by pericardiocentesis and repair of the rupture site as quickly as possible. Measures to prevent cardiac rupture include the administration of beta-blockers and angiotensin-converting enzyme inhibitors unless contraindications exist, and the avoidance of steroidal and nonsteroidal anti-inflammatory agents such as ibuprofen and indomethacin.

Subacute ventricular free wall rupture complicating myocardial infarction

Myocardial free wall rupture accounts for between 8% and 17% of mortality after myocardial infarction. In up to 40% of cases death occurs subacutely over a matter of hours, not minutes. Illustrative clinical cases and data suggest that a high degree of clinical suspicion, along with the early use of echocardiography, could significantly reduce mortality resulting from myocardial free wall rupture complicating myocardial infarction. Myocardial free wall rupture should be suspected in patients with recent myocardial infarction who have recurrent or persistent chest pain, hemodynamic instability, syncope, pericardial tamponade, or transient electromechanical dissociation. In this clinical situation, emergent echocardiography showing a pericardial effusion or pericardial thrombus is highly suggestive of free wall rupture. Surgical exploration and rupture repair is the definitive diagnostic and therapeutic procedure.

Diagnosis of subacute ventricular wall rupture after acute myocardial infarction: sensitivity and specificity of clinical, hemodynamic and echocardiographic criteria

When ventricular free wall rupture after acute myocardial infarction is not followed by sudden death, it is referred to as subacute ventricular rupture. The sensitivity and specificity of clinical, hemodynamic and echocardiographic diagnostic variables obtained at bedside are unknown and were therefore prospectively studied in 1,247 consecutive patients with acute myocardial infarction including 33 patients with subacute ventricular rupture diagnosed at operation (group A) and 1,214 patients without ventricular rupture (at operation, postmortem study or at discharge) (group B). The incidence of syncope, recurrent chest pain, hypotension, electromechanical dissociation, cardiac tamponade, pericardial effusion, high acoustic intrapericardial echoes, right atrial and right ventricular wall compression identified in two-dimensional echocardiograms and hemopericardium demonstrated during pericardiocentesis was higher in group A than in group B (p less than 0.00001). The presence of cardiac tamponade, pericardial effusion greater than 5 mm, high density intrapericardial echoes or right atrial or right ventricular wall compression had a high diagnostic sensitivity (greater than or equal to 70%) and specificity (greater than 90%). The number of false positive diagnoses was always high for each diagnostic variable alone (greater than 20%), but the combination of clinical (hypotension), hemodynamic (cardiac tamponade) and echocardiographic variables allowed a sensitivity of greater than or equal to 65% with a small number of false positive diagnoses (less than 10%) and provided useful information for therapeutic decisions. The diagnosis of subacute ventricular rupture requires a surgical decision. Twenty-five (76%) of the 33 patients with subacute ventricular rupture survived the surgical procedure and 16 (48.5%) are long-term survivors. Thus, subacute ventricular wall rupture is a relatively frequent complication after acute myocardial infarction that can be accurately diagnosed and successfully treated.