History and clinical findings: A 48-year-old man with advanced light-chain plasmacytoma was admitted because of severe dyspnoea and tachycardia. Physical examination revealed peripheral cyanosis and signs of right heart failure.
Investigations: The partial pressure of oxygen and CO2 in arterial blood were both reduces (72 mm Hg and 33 mm Hg, respectively). Liver enzyme activities were increased, there was right heart enlargement radiologically and the ECG showed low voltage and typical signs of right heart strain. Echocardiography revealed cardiac metastases of the plasmacytoma with subtotal right ventricular outflow tract obstruction (RVOTO), without any signs of pulmonary emboli.
Treatment and course: Palliative radiotherapy to the heart reduced the intracardiac tumor size and improved the patients' general condition. The signs of the RVOTO were markedly reduced in both the ECG and the echocardiogram. But after this initial improvement pneumonia developed, of which the patient died. Autopsy revealed radiation pneumonia with extensive fibrosis as the immediate cause of death.
Conclusion: In patients with advanced neoplasia cardiac metastasis should be included in the differential diagnosis of dyspnoea, tachycardia or hypotension of uncertain etiology. Echocardiography is the diagnostic tool of choice.