Nonbacterial Thrombotic Endocarditis: Presentation, Pathophysiology, Diagnosis and Management.

Initially described in 1936, non-bacterial thrombotic endocarditis (NBTE) is a rare entity involving sterile vegetations on cardiac valves. These vegetations are usually small and friable, typically associated with hypercoagulable states of malignancy and inflammatory diseases such as systemic lupus erythematosus. Diagnosis remains challenging and is commonly made post-mortem although standard clinical methods such as echocardiography (transthoracic and transesophageal) and magnetic resonance imaging may yield the clinical diagnosis. Prognosis of NBTE is poor with very high morbidity and mortality usually related to the serious underlying conditions and high rates of systemic embolization. Therapeutic anticoagulation with unfractionated heparin has been described as useful for short term prevention of recurrent embolic events in patients with NBTE but there are no guidelines for management of this disease.

Carcinoid Heart Disease: Pathophysiology, Pathology, Clinical Manifestations, and Management.

Carcinoid heart disease (CHD) is a rare and potentially lethal manifestation of an advanced carcinoid (neuroendocrine) tumor. The pathophysiology of CHD is related to vasoactive substances secreted by the tumor, of which serotonin is most prominent in the pathophysiology of CHD. Serotonin stimulates fibroblast growth and fibrogenesis, which can lead to cardiac valvular fibrosis. CHD primarily affects right heart valves, causing tricuspid and pulmonic regurgitation and less frequently stenosis of these valves. Left heart valves are usually spared because vasoactive substances such as serotonin are enzymatically inactivated in the lung vasculature. The pathology of CHD is characterized by plaque-like deposition of fibrous tissue on valvular cusps, leaflets, papillary muscles, chordae, and ventricular walls. Symptomatic CHD usually presents between 50 and 70 years of age, initially as dyspnea and fatigue. Echocardiography is the mainstay of imaging and demonstrates thickened right heart valves with limited mobility and regurgitation. Treatment focuses on control of the underlying carcinoid syndrome, targeting subsequent valvular heart disease and managing consequent heart failure. Surgical valve replacement and catheter-directed valve procedures may be effective for selected patients with CHD.