A left ventricular aneurysm (LVA) is most commonly the result of myocardial infarction, usually involving the anterior wall. When a heart attack occurs in the left ventricle (left lower pumping chamber of the heart), a scar may form. The scarred area can become thin and bulge out with each beat. The bulging thin area is called an aneurysm. The aneurysm, along with other heart damage you may have, makes your heart work harder to pump blood throughout your body. Initially your heart is able to handle the additional work, but over time, your left ventricle becomes larger than normal and pumps less effectively. An apical aneurysm is infrequently seen in hypertrophic cardiomyopathy but, in Latin America, is a common and characteristic finding in Chagas’ disease.
A left ventricular aneurysm may be asymptomatic, but can be the cause of congestive heart failure, sustained ventricular tachyarrhythmias, and arterial embolism.
The presence of an LVA may be suspected clinically, particularly if there is persistent ST elevation on the electrocardiogram in the setting of one of the complications of LVA. A LVA is often suspected on the chest xray, but the diagnosis of an LVA is definitively made with imaging techniques including echocardiography, radionuclide ventriculography, or contrast ventriculography at the time of cardiac catheterization.
Patients with small to moderate asymptomatic aneurysms can be treated medically with an anticipated five-year survival of up to 90 percent. Therapy consists of afterload reduction for LV enlargement, usually with an angiotensin converting enzyme inhibitor, antiischemic medications for angina, and anticoagulation if there is significant LV dysfunction and evidence of thrombus within the aneurysm or LV.
Patients with large asymptomatic aneurysms are generally followed closely for progressive left ventricular dilation (unless there is some other indication for surgery such as left main or severe three vessel disease). Similar to other situations of a chronic volume load, such as mitral or aortic regurgitation, a progressive increase in LV diameter and/or decrease in LV ejection fraction are considered to be an indication for surgery even before the development of overt congestive heart failure.
The indications for surgery in patients with a symptomatic LVA have remained unchanged over the years and include medically refractory:
- Congestive heart failure
- Angina pectoris
- Systemic embolization
- Malignant ventricular tachyarrhythmias
Surgical repair of an LVA is very effective, and results in a significant improvement in patient survival, symptoms, and functional class compared to medical treatment. Furthermore, a marked decrease in operative mortality has been achieved in the past two decades, resulting in an expansion of indications for surgery.
LVA Reconstructive Surgery
Left ventricular reconstructive surgery allows the surgeon to remove the scarred, dead area of heart tissue and/or the aneurysm and return the left ventricle to a more normal shape. The goal is to improve heart failure and/or angina (chest pain) symptoms and possibly improve the pumping ability of your heart.
During this procedure, the surgeon makes a small incision in the left ventricle and finds the exact location of the dead or scarred tissue. The surgeon then places two or more rows of circular stitches around the border of the dead tissue to separate it from healthy tissue. The stitches are then pulled together (like a purse-string) to permanently separate the dead tissue from the rest of the heart. Sometimes an area of scar tissue is removed first before the stitches are pulled together.
On rare occasions, if there is a lot of dead tissue to remove and standard stitches are not enough to exclude the area, a patch may be placed. Lastly, the surgeon closes the outside of the ventricle and reinforces the area with another row of stitches.
The two surgical techniques most commonly used are the linear repair and the ventricular endoaneurysmorrhaphy. With linear repair, the aneurysm is resected, intracavitary clot is removed, and the edges are sutured using two strips of Teflon felt for reinforcement.
With endoaneurysmorrhaphy, the aneurysm is opened parallel to the interventricular septum. Any clot is removed and an elliptical patch (Dacron or bovine pericardium) is sutured to the “red\white” border zone using a continuous suture of 4-0 polypropylene. The excess aneurysm is resected, leaving a residual that is closed above the patch using a continuous suture of 4-0 polypropylene .
The majority of the operations for repair of LVA are preformed via a median sternotomy incision using cardiopulmonary bypass. However, in unusual circumstances, the operation can be performed via a left thoracotomy, particularly for posterior aneurysms.
Since left ventricular function is significantly impaired in most patients who undergo surgery, adequate myocardial protection is of paramount importance. The current concept of myocardial preservation strategy comprises several components:
- Use of blood rather than crystalloid cardioplegia, delivered both antegrade via the aortic root and retrograde via the coronary sinus
- Induction of myocardial diastolic arrest using warm (37ºC) c-amino-acid enriched blood cardioplegia, followed by intermittent cold (4ºC) blood cardioplegia repeated every 20 minutes during aortic clamping and delivered via the aortic root and the vein grafts. Topical cooling is enhanced by using continuous cold (4ºC) saline irrigation
- Anastomosis to the “culprit” vessel that supplies an area of acute ischemia is performed first
- Warm reperfusion (“hot shot”) using 37ºC c-amino-acid enriched blood cardioplegia prior to aortic declamping
- Strict prevention of left ventricular distention by placing left ventricular or pulmonary artery vent suction lines
Continuous warm blood cardioplegia has been suggested as an alternative and possible superior approach in patients with acute ischemia. However, the data are still controversial and inconclusive.
You can expect to stay in the hospital about 5 to 7 days, depending on the course of your recovery. During your hospital stay, you will work with a cardiac rehabilitation specialist who will help you gradually increase your activity. This will help speed up your recovery.
Some patients may require a special device called an implantable cardioverter-defibrillator (ICD) to treat a serious abnormal heart rhythm. If this is required, your cardiologist will discuss the details about the device and the implantation procedure. Under specific circumstances, you may have a test called an EP study (electrophysiology study) before you go home to evaluate your heart rhythm.
Before you leave the hospital, you will receive specific information about wound care, medications, warning signs to look for and who to call if you experience any problems after you go home.