P1694 Prosthetic mitral valve infective endocarditis complicated by left ventricle to right atrial fistula
Abstract Left ventricle (LV) to right atrial (RA) shunt is a rare type of ventricular septal defect. Acquired LV-RA shunt is rare and may occur as complication of cardiac surgery, endocarditis, thoracic trauma or myocardial infarction. Infective endocarditis is the second most important cause of this type of shunt. Case presentation A 44 year old female patient presented to our hospital complaining of progressive exertional dyspnea and palpitations for 6 months, and high grade fever for 2 weeks. The patient had history of mitral valve replacement with mechanical prosthesis 16 years ago. The patient had no history of recent invasive procedures or dental interventions. General examination revealed an irregular pulse at rate of 100 beats per minute (bpm), blood pressure of 100/60 mmHg, temperature of 38.5 ͦ C and congested neck veins. Cardiac examination revealed an audible prosthetic mitral click with a harsh pansystolic murmur heard on the apex and left sternal border, and an accentuated P2 over the pulmonary area. Her resting electrocardiogram (ECG) showed atrial fibrillation with ventricular response of 110 bpm. Her laboratory investigations revealed normochromic normocytic anemia with Hemoglobin level of 8 g/dl (13-16), and leucocytosis with white blood cell count of 16.24 103 cell/ ul (4.00-11.00); as well as elevated C-reactive protein (CRP) level of 73 (0-3). Her international normalized ratio (INR) was 3 (1-1.3) on warfarin 5 mg. Transthoracic echocardiography (TTE) revealed a dehiscent prosthetic mitral valve with severe paravalvular regurgitation, severe tricuspid valve regurgitation and pulmonary hypertension with predicted resting pulmonary artery systolic pressure of 60 mmHg. It also showed an abnormal jet passing from the LV into the RA above the tricuspid valve during systole, both right and left ventricular systolic functions were preserved. Subsequent 2D/3D transoesophageal echocardiography (TEE) confirmed the TTE findings with detection of LV-RA fistula with significant left to right shunt; it also visualized multiple vegetations attached to the mitral annulus at the site of the valve dehiscence. The patient was diagnosed with prosthetic mitral valve infective endocarditis, empirical antibiotics were started and the patient was referred for another center for urgent surgery. Redo mitral valve replacement, tricuspid valve repair and closure of the defect were done; the patient developed complete heart block postoperatively and permanent pacemaker was inserted. Conclusion Infective endocarditis remains a major health problem with high mortality and severe complications. It is important to keep high index of suspicion in high risk patients for infective endocarditis as delayed diagnosis increases the risk of serious complications and mortality, and makes surgical intervention, if indicated, more demanding with increased incidence of perioperative complications. Abstract P1694 Figure. TTE&TEE of prosthetic mitral IE