Case Presentation: A 49-year-old woman of German ancestry without any prior medical history presented to the hospital with complaints of shortness of breath and right lower extremity for 2 weeks. Her examination was notable for tachycardia, notable loud systolic ejection murmur at cardiac apex. Labs revealed mild leukocytosis, elevated D-dimer, BNP, mild hepatocellular transaminitis and normal troponin and TSH levels. Her EKG revealed atrial fibrillation with rapid ventricular response and chest x-ray revealed pulmonary vascular congestion. CT angiogram of chest revealed 1.5 cm nodule in the right lung with no evidence of pulmonary embolism. Transthoracic echocardiogram demonstrated an ejection fraction of 60 to 65% with mild right ventricular dysfunction and severely stenotic rheumatic appearing mitral valve with reduced mitral valve area of 1.4 cm². She was managed with warfarin for anticoagulation, diltiazem for rate control and effectively diuresed prior to discharge. The right and left heart catheterization showed 70% stenosis of obtuse marginal, and she underwent coronary artery bypass grafting, mechanical mitral valve replacement and left atrial appendage excision.

Discussion: Rheumatic heart disease (RHD) is one of the long-term sequelae of acute rheumatic fever and characteristically affects the mitral valve resulting in mitral stenosis and regurgitation. Even though there has been a consistent decline in the presence of rheumatic heart disease in United States and only 30 to 50% of the cases have recognized ARF, it should be considered as a differential in any new onset of heart failure or atrial fibrillation. Gradually worsening exertional dyspnea is often the most initial symptoms of rheumatic mitral valve disease. Because of the slow progression of rheumatic heart disease, patients might initially present with complications such as atrial fibrillation, heart failure or embolic stroke. Transthoracic echocardiogram can help diagnose, quantify the severity of lesion and demonstrate the valvular anatomy. Patients with RHD and AF are at increased risk of arterial embolization and Vitamin K Antagonists (VKA) are only the studied anticoagulants to have shown to reduce the risk of embolization. Only balloon mitral valvotomy and surgery have shown to have sustained long-term benefits in symptomatic patients.

Conclusions: Less than half cases of ARF are identified and many patients have undetected multiple episodes of ARF in their childhood. Number of ARF episodes strongly correlates with the progression of the disease. However, patients with rheumatic mitral disease usually do not present until valve area is significantly narrowed. Progression to severe valvular disease increases risk of heart failure, atrial fibrillation and embolic stroke which might be the initial presenting symptom. Our case demonstrates the need to consider rheumatic heart disease in patients with new onset atrial fibrillation and heart failure even in those without a history of acute rheumatic fever.