Severe Dilated Cardiomyopathy Due to Polycythemia Vera - A Rare Etiology

Abstract

A 40-year old gentleman presented with history of exertional dyspnoea over 2 months. He had decreased exercise tolerance from New York Hear Association class I to class III in 2 months. He also reported orthopnea and paroxysmal dyspnoea for last 2 weeks of his presentation. He did not report any chest pain, palpitations, diaphoresis or dizziness. He had no symptoms of cough, fever, weight loss or any other symptoms to suggest systemic infection. He had no significant past medical or surgical history and was not taking any medications. Family history did not reveal any cardiac diseases including any sudden deaths. He never smoked cigarettes and consumed alcoholic occasionally. There was no history of drug abuse and did not report of having excessive energy drinks. On examination, his respiratory rate was 18, pulse rate 70 and regular with blood pressure of 125/85 and was afebrile. Cardiovascular examination revealed a displaced apex beat with dual heart sounds and no murmurs. Jugular venous pulse was not elevated and had bi basal coarse crackels on auscultation of his chest. Abdominal examination did not reveal any organomegaly and there was no peripheral edema. Blood tests showed haemoglobin of 19.5g/dl with haemocrit of 51.5% and normal platelets and white cell counts. The diagnosis of polycythemia vera was confirmed on the basis of positive JAK2 mutation. Chest X ray showed cardiomegaly with mild interstitial edema. A trans-thoracic echocardiogram showed severe dilated cardiomyopathy with ejection fraction of 18%. He underwent a coronary angiogram which showed normal coronary arteries ruling out ischemic cardiomyopathy. Other blood tests including comprehensive metabolic panel, thyroid functions, genetic screening and urine toxicology screening were all within normal limits. Figure 1: Extensive fibrosis of myocardium. Abstract Polycythemia vera (PV) is a myeloproliferative disorder characterised by panhyperplastic bone marrow with most prominent feature of increased red cell mass resulting from excessive erythropoiesis. This translates to sludging of blood flow due to hyperviscosity and thrombosis leading to poor oxygen delivery to tissues. Thrombosis of cardiovascular system is extremely rare in PV with limited data available in literature. We describe a case of a 40-year old gentleman with new onset of severely dilated cardiomyopathy secondary to PV. The likely pathophysiological mechanism is the necrosis of the cardiac myocytes due to micro-thrombi.