Patients undergoing mechanical mitral valve replacement:
Although mechanical valves necessitate systemic anticoagulation, careful monitoring of the international normalized ratio (INR) reduces the risk of thromboembolic events and hemorrhagic complications, and improves overall survival. Patients undergoing mechanical A VR generally have a target INR of 2 to 3 times normal. Patients undergoing mechanical mitral valve replacement frequently have increased left atrial size, concomitant AF, and are at higher risk for thromboembolism than those undergoing mechanical AOR, and are thus recommended to have a target INR 2.5 to 3.5 times normal. When managed appropriately, the yearly thromboembolic and bleeding risks in these patients are 1 to 2%, and 0.5 to 2%, respectively.
An absolute contraindication to a coronary artery bypass operation is:
Patients with ischemic cardiomyopathy are a heterogeneous group, and, as with any surgery, appropriate patient selection is central to success. In one retrospective study of 96 patients with ischemic cardiomyopathy (ejection fraction [EF] ≤ 25%), age, and poor distal vessel quality were predictors of poor outcomes. Mortality in patients with poor vessel quality was 100%, compared with 90% when vessel quality was fair and 10% when it was good. Therefore, poor vessel quality should be considered a contraindication to surgical revascularization even in the presence of angina.
Approximately 50% of benign cardiac tumors are:
Cardiac neoplasms are rare, with an incidence ranging from 0.00 1 to 0.3% in autopsy studies and a 0.15% incidence in major echocardiographic series. Benign cardiac tumors are most common and account for 75% of primary neoplasms. Approximately 50% of benign cardiac tumors are myxomas, with the remainder being papillary fibroelastomas, lipomas, rhabdomyomas, fibromas, hemangiomas, teratomas, lymphangiomas, and others, in order of decreasing frequency. Most malignant primary cardiac tumors are sarcomas (angiosarcoma, rhabdomyosarcoma, fibrosarcoma, leiomyosarcoma, and liposarcoma), with a small incidence of malignant lymphomas. Metastatic cardiac tumors, while still infrequent, have been reported to occur 100-fold more often than primary lesions.
The majority of cardiac myxomas arise from:
Cardiac myxomas are the most common cardiac tumor and are characterized by several distinguishing features. About 75% of the time, they arise from the interatrial septum near the fossa ovalis in the left atrium. Most others will develop in the right atrium, but, less commonly, they can arise from valvular surfaces and the walls of other cardiac chambers. Macroscopically, these tumors are pedunculated with a gelatinous consistency, and the surface may be smooth (65%), villous, or friable.
The following is NOT true of rhabdomyomas:
In children, rhabdomyomas are the most common primary cardiac tumor, whereas fibromas are the most commonly resected cardiac tumor. Rhabdomyomas are myocardial hamartomas that are often multicentric in the ventricles. About 50% of cases are associated with tuberous sclerosis, and while resection is occasionally necessary, most disappear spontaneously. Fibromas are congenital lesions that one-third of the time are found in children younger than 1 year. These tumors, conversely, are ordinarily solitary lesions found in the inner interventricular septum, and they may present with heart failure, cyanosis, arrhythmias, syncopal episodes, chest pain, or sudden cardiac death.
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