Two types of malignancies affecting the heart have been described in AIDS”Kaposi’s sarcoma and malignant lymphoma, with Kaposi’s sarcoma being the more common. Kaposi’s sarcoma is found mostly in HIV-positive male homosexuals, with primary Kaposi’s sarcoma being rare and having declined in incidence since the early 1980s. Kaposi’s sarcoma may involve the epicardium (a common location), myocardium, and/or pericardium.
Malignant cardiac lymphoma may be primary or secondary and is usually high-grade, with Burkitt-like cells (small and noncleaved) or large-cell immunoblastic plasmacytoid types. In most cases, they appear to originate from B cells.
Do cardiac abnormalities improve in AIDS patients?
There have been few specific follow-up studies of AIDS-related cardiac findings. In one study, Blanchard et al. reported approximately 1 year’s follow-data on AIDS and asymptomatic HIV-positive patients. Over the follow-up, 44% of the AIDS patients and only 5% of the asymptomatic HIV-positive patients died. Echocardiographic abnormalities were common in both groups, but persistent LV dysfunction was more prevalent in the AIDS group and had the grim prognosis of 100% mortality in 1 year. Resolution of cardiac abnormalities was seen with LV dysfunction in 43%, right ventricular enlargement in 44%, and without specific intervention, pericardial effusion resolution in 42%.
1Why are the cardiac lesions occasionally transient?
This issue needs further study, but it is possible that infectious myocarditis may be the major cause of LV dysfunction and pericarditis and that there is transient occurrence of these cardiopathic agents. The right ventricular transient changes are most likely due to changes in pulmonary hypertension associated with opportunistic pulmonary infections. Therefore, it is important to have patients re-evaluated, especially if symptoms change, as medications may need frequent adjustments. We perform echo-Doppler studies on our AIDS patients as symptoms dictate or electively every year if they have significant cardiac involvement or advanced disease.
What are the clinical manifestations of AIDS myocarditis?
The clinical manifestations of AIDS myocarditis depend on the severity of the inflammatory process, i.e., focal or diffuse, and/or the location of the lesion. For example, if the focus is in the His bundle, the patient presents with conduction abnormalities; diffuse disease presents with full-blown congestive heart failure or with chest pain, shortness of breath, or significant arrhythmias. Most patients have no clinical manifestations or only subtle clinical findings.
Describe the central mechanisms underlying the cardiovascular responses to exercise.
With anticipation of, and in early exercise, there is an immediate and progressive withdrawal of vagal tone, causing an increase in heart rate. Venous return is augmented by the action of muscular contraction, resulting in increased preload and thus stroke volume via the Frank-Starling mechanism. Concurrently, there is an increase in catecholamine release, further increasing heart rate as well as contractility.