Tumors involving the heart may be primary or metastatic; both are rare. Although a variety of metastatic tumors has been described in the heart, the most common are malignant melanomas, leukemia, and lymphomas. The treatment of metastatic tumors is treatment of the primary malignancy.
Primary cardiac tumors may be benign or malignant. Myxoma is the most common primary tumor of the heart and is usually benign. Almost all malignant cardiac tumors are sarcomas, angiosarcoma and rhabdomyosarcoma being the most frequent. It is impossible prior to histologic examination to distinguish benign from malignant tumors, but malignant tumors are more likely to present with evidence of metastases, invasion or rapid growth. Tumor type me be identified occasionally from tissue at the time of peripheral embolectomy. Malignant primary tumors of the heart have a very poor prognosis.
Myxomas may arise from the endocardial surface of any cardiac chamber, but the majority arise from the left atrium, most commonly in the region of the fossa ovalis. They are usually pedunculated. As a general rule, 10 per cent of cardiac myxomas manifest malignant characteristics and 10 per cent arise in locations other than the left atrium. Occasionally they can be bilateral and usually present in one of three general ways:
(1) progressive interference with mitral valve function that causes decreased exercise tolerance, dyspnea on exertion, and pulmonary edema; syncope or presyncope may occur;
(2) stroke or occlusion of a major systemic artery due to an embolus,
(3) systemic manifestation that include fever, wasting arthralgia’s, malaise, anemia, or Raynaud s phenomenon.
If the left atrial myxoma interferes with mitral valve function, a regurgitant valvular murmur may occur. A murmur resembling mitral stenosis may be present owing to obstruction of the valve orifice during diastole. The intensity of the murmur may change with changes in body position. An early diastolic sound termed a tumor polp may occur secondary to movement of the tumor toward the left ventricle in early diastole. The erythrocyte sedimentation rate, gamma globulins, and white blood cell count may be elevated. The cause of the systemic manifestations is not clear but may result from products secreted by the tumor, necrotic tumor debris, or an immunologic reaction.
Cardiac myxoma is usually diagnosed by echocardiography. Two-dimensional echocardiography shows the tumor location and movement with the cardiac cycle. Cardiac catheterization with angiocardiography usually is not necessary when the diagnosis has been established noninvasively and is associated with risk of tumor embolus.
Cardiac myxomas should be excised surgically once identified. A recurrent or second myxoma occurs following resection in a small number of patients. Atrial myxoma occasionally may behave as a malignant tumor and demonstrate metastases.
Blunt chest trauma is especially common after steering wheel impact from an automobile accident. It may produce myocardial contusion, resulting in myocardial hemorrhage and at times some degree of necrosis. Often there is little or no residual myocardial scar once healing is complete. Large contusions may lead to myocardial scars, cardiac or septal rupture, congestive heart failure, or formation of true or false aneurysms. Necrosis or hemorrhage involving the cardiac conduction system can produce intraventricular or atrioventricular block. Coronary artery laceration, valvular damage, or pericardial tears may occasionally occur after blunt trauma. The chest pain of myocardial contusion is similar to that of myocardial infarction and is often confused with musculoskeletal pain from the chest trauma. The electrocardiogram at the time of injury may show a diffuse injury pattern similar to that of pericarditis. Later, the electrocardiogram may reveal serial development of Q waves-similar to that of acute myocardial infarction if significant necrosis has occurred. Bradyarrhythmias and tachyarrhythmias are common. Contractile abnormalities are usually not severe unless concomitant injury to a valve or the septum has occurred. The MB fraction of creatine kinase is elevated. Myocardial contusion is usually treated similarly to myocardial infarction with initial monitoring and subsequent progressive ambulation. Anticoagulants should not be administered to patients with myocardial contusion. If the patient survives the acute episode, his long-term prognosis is usually good, although late complications such as ventricular arrhythmias occasionally occur.
Rupture of the aorta is a common consequence of blunt trauma. It most commonly occurs just distal to the take-off of the left subclavian artery. The patient may complain of pain in the back or chest similar to that of aortic dissection. The chest x-ray usually reveals widening of the mediastinum. Many patients demonstrate increased arterial pressure in the upper extremities and decreased arterial pressure and pulse pressure in the lower extremities. Signs of decreased renal or spinal cord perfusion may become evident. The diagnosis is usually confirmed by aortography, and the treatment is surgical.
Penetrating cardiac injuries may be due to external objects such as bullets or knives and also bony fragments occurring, from chest injury. Because of its anterior location, the right ventricle is most commonly involved. Iatrogenic causes of cardiac penetrating injury include perforation of the heart during catheterization or cardiac trauma from cardiopulmonary resuscitation.
Penetrating injury to the heart may present-as exsanguinating hemorrhage with hemothorax or cardiac tamponade if hemorrhage has been limited to within the pericardial sac. Immediate pericardiocentesis and administration of large volumes of fluids may be performed as preparations are beign made for emergency surgery. A “post-pericardiotomy type of pericarditis, infection, arrhythmias, aneurysm formation, and ventricular septal defects are late complications of penetrating cardiac injury.
Dr. Afsaneh Jeddi