A male in his 70s complained of dyspnea that because of its severity and his disturbed level of consciousness required emergency hospital admission. A cardiac ultrasound was performed which showed a tumor occupying the left atrium, and a diagnosis of cardiogenic shock secondary to cardiac tumor was made. He underwent urgent tumor resection resulting in his recovery from cardiogenic shock. Pathological examination of the resected tumor showed small cell carcinoma. Although the primary lesion was unknown, because of the extent of the tumor from the left pulmonary vein to the left atrium, a lung primary was diagnosed. The patient requested supportive care only and declined active treatment of his cancer. He passed away one year post operatively. Although cardiac metastasis is often asymptomatic and rarely diagnosed while alive, more attention is needed to recognize cardiac metastasis as a cause of cardiogenic shock and sudden death.