Pulmonary tumor thrombotic microangiopathy is a rare condition in which embolization of tumor cells to the pulmonary arterioles causes fibrocellular intimal thickening and activation of the coagulation cascade resulting in pulmonary hypertension and right heart failure. Herein, we highlight a young 35-year-old male with no known past medical history who presented with recurrent syncope and dyspnea, and was found to have severe right heart failure and pulmonary hypertension. He developed sudden clinical deterioration and died after a cardiac arrest. Autopsy revealed poorly differentiated gastric adenocarcinoma and pulmonary tumor thrombotic microangiopathy. New onset severe pulmonary hypertension and right heart failure without any other obvious etiology should encourage the reader to evaluate for pulmonary tumor thrombotic microangiopathy and undergo a diligent search for underlying malignancy. This case highlights recurrent syncope as a rare presentation of this rapidly fatal disease.