THE “UNDER-LINING” CAUSE OF RIGHT HEART FAILURE AFTER CARDIAC SURGERY Sarah Ifteqar MBBS, Christopher Balwanz MD and Deepak Parashara MD INTRODUCTION Heart failure is one of the most common causes requiring frequent hospitalizations and affects around 5.1 million Americans. Though the etiology is evident in most cases, sometimes uncommon and potentially treatable causes may be missed. CASE REPORT A 64-year-old man presented with fatigue and dyspnea on exertion (DOE) and atrial fibrillation. Echo revealed a normal left ventricular ejection fraction (LVEF) with moderate aortic insufficiency and severe mitral stenosis, for which bioprosthetic aortic and mitral valve replacements and a Cox MAZE procedure was done. He presented 3 weeks later with worsening DOE and bilateral lower extremity(LE) edema. Echo revealed LVEF of 50% with large Rt pleural and pericardial effusion without evidence of tamponade for which a pericardiocentesis and thoracentesis was done, in addition to diuresis, aspirin and colchicine, with improvement in symptoms. 2 weeks later he again presented with right heart failure. Echo revealed LVEF 50%, severe tricuspid regurgitation, mild pericardial thickening with no significant effusion, septal bounce during early diastole, and a distended inferior vena cava. Right heart catheterization had elevation and equalization of pressures among the right atrium (RA), right ventricle (RV) diastolic, and pulmonary capillary wedge pressure (~23mmHg). The RA pressures showed prominent x and y descent while the RV pressures showed a “dip and plateau” sign. Left heart catheterization was attempted, but we were unable to safely pass the catheter across the new bioprosthetic aortic valve. He then underwent pericardiectomy for constrictive pericarditis as well as prosthetic tricuspid valve replacement. Post-operative course was complicated by prolonged inotrope dependence, complete heart block requiring pacemaker, respiratory and renal failure eventually resulting in death soon after. DISCUSSION Constrictive pericarditis is a condition that develops due to inflammation of the pericardial sac resulting in scarring and fibrosis. The most common etiology in the developed world is idiopathic, postsurgical, or radiation injury. In developing countries tuberculosis continues to be the most common cause. Although constrictive pericarditis usually takes years to develop it may develop relatively rapidly, especially following cardiac surgery. Constrictive pericarditis is a progressive disease and with the exception of patients with transient constriction (trial of steroids may be attempted), surgical pericardiectomy is the definitive treatment. In selective patients diuretics and salt/fluid restriction may be attempted as a temporizing measure. Long-term results are worse in patients with radiation-induced disease, impaired renal function, relatively high pulmonary artery systolic pres­sure, reduced left ventricular ejection fraction, moderate or severe tricus­pid regurgitation and advanced age. CONCLUSION Given importance of timely intervention, early recognition of iatrogenic constrictive pericarditis is crucial especially with the exponential increase in cardiac interventions in recent years to help improve morbidity and mortality. REFERENCES Braunwald,s Heart disease, A textbook of cardiovascular medicine. Ling LH, Oh JK, Schaff HV, et al: Constrictive pericarditis in the modern era: Evolving clinical spectrum and impact on outcome after pericardiectomy. Circulation 100:1380, 1999. Go AS, Mozaffarian D, Roger VL, Benjamin EJ, Berry JD, et al. Heart disease and stroke statistics—2013 update: a report from the American Heart Association. Circulation. 2013;127:e6–e245.