Case Discussion <Case report> A 16-year-old Chinese girl was admitted due to high fever and bilateral chest pain for two days. The pain attacked intermittently and radiated to upper back. On examination, she had a temperature of 40.2 °C and a tachycardia of 120/min. Her blood pressure was 150/80 mmHg and her respiratory rate was 38/min. Neither lymph node enlargement nor jugular vein enlargement was noted on the neck. Her breathing sound was clear. A grade II/VI systolic murmur was noted over left upper sternal border. The total white cell count was 4560 per cubic millimeter and biochemical tests were normal. The chest roentgenogram showed multiple patches over bilateral lung fields. Empirical antibiotics with ceftazidime and amikacin were started under the consideration of septic pulmonary emboli. Later, blood culture yielded methicillin-sensitive Staphylococcus aureus and antibiotics was shifted to oxacillin. Transthoracic echocardiogram showed normal size of cardiac chambers but a vegetation over tricuspid valve. Transesophageal echocardiogram revealed the vegetation and dilatation of right coronary artery with a fistula draining into right atrium (figure 1 ). In addition, ultrafast computed tomography (Imatron, South San Francisco, CA) further demonstrated an aneurysmal dilatation (figure 2). She was treated with a six-week course of antibiotic and her recovery was uneventful. Cardiac catheterization was performed six months later and showed a large diameter fistula from proximal right coronary artery to right atrium (figure3 ). The pulmonary to systemic flow ratio (Qp/Qs) is 1.3:1. Later, operation confirmed the anatomical diagnosis and the patient underwent surgical ligation of fistula. She was symptoms free for one year after operation. Table 1. Laboratory data [CBC+PLT] WBC RBC HB PLT K/μL M/μL g/dL  K/μL 4.56 4.43 13.5 112.0 Seg Eos Baso Mono Lym % % % % % 82.7 0.3 0.2 5.3 11.5 [ Biochemistry ] ALB GLO BUN CRE T-BIL AST GLU mg/dl mg/dl mg/dl mg/dl mg/dl U/l mg/dl 4.6 3.8 20.5 0.8 0.8 60.0 103.0 Na K Cl Ca Mg Mmmole/l mmole/l mmole/l mmole/l mmole/l 144.0 4.3 111.0 1.98 0.8 Discussion Most patients with congenital coronary artery fistula (CAF) have no symptoms. Congestive heart failure and angina occurred in approximately 20% of patients, respectively. Bacterial endocarditis is rare, reported in only 4% of the patients. The endothelial damage over tricuspid valve by the turbulence flow via fistula might explain the unusual site of the vegetation in this case. In the previously reported case, the diagnosis depended on coronary angiography. Angiography is the traditional method used for the definite diagnosis of CAF. Transesophageal echocardiography and ultrafast computed tomography could provide more satisfactory images of the origin, course and drainage site of CAF. Furthermore, in contrast to conventional angiography, ultrafast computed tomography provides a more reliable tool to detect coronary vascular anomaly. The management of asymptomatic patients with small CAF (Qp/Qs<1.5) remains controversial, including elective ligation and medication only. In contrast, surgical ligation of small CAF is favored for patients with complications, such as bacterial endocarditis. Several reports have demonstrated that surgical management is safe and effective. Percutaneous transcatheter embolic occlusion technique using a variety of material has been used for the treatment of CAF in recent years. However, the risk and advantage are still under investigation. <Legend of figure> Figure 1 : Transesophageal echocardiography shows dilatation of right coronary artery with an aneurysmal fistula. A vegetation is identified over tricuspid valve (left arrow). Color duplex of the same field reveals a shunt from aneurysm to right atrium (right arrow). (Ao: arota, RCA: right coronary artery, A: aneurysm, F: fistula, LA: left atrium, RA: right atrium) Figure 2 : Enhanced ultrafast computer tomography shows dilated right coronary artery (black arrow) with a fistula (white arrow). The fistula has an aneurysmal tip (A) bulging into the right atrium (RA). Figure3 : Cardiac catheterization identifies a large coronary fistula (white transverse arrow) ending into an aneurysm (a) which drains into right atrium. Notice the double contour of aneurysm and right atrium (white oblique arrow). The distal right coronary artery is faint (black arrow). 繼續教育考題 1. (C) What is the most common pathogen in right side infective endocarditis? A E.Coli B Viridans Streptococcus C Staphyloccous aureus D Samonella 2. (B) What is least likely as a complication in right side infective endocarditis in patients without right to left shunt? A Septic pulmonary emboli B Brain abscess C Empyema D Hemoptysis 3. (D) What is the least cause of septic pulmonary emboli? A Right side infective endocarditis B Psoas muscle abscess C Visceral abscess D Left side infective endocarditis without left to right shunt 4. (D) What is not the common symptom or sign of right side infective endocarditis? A Fever B Cough C Hemoptysis D Janeway lesions 5. (D) Which valve is least like involving infective endocarditis (native)? A Aortic valve B Mitral vlave C Tricuspid valve D Pulmonary valve 6. (B) What kind of congenital heart disease dose not increase the risk of infective endocarditits? A Ventricular septal defect B Atrial septal defect C Bicuspid aortic valve D patent ductus arteriosus 7. (D) Which symptom is not associated with CAF? A Exertional dyspnea B Angina C Congestive heart failure D Facial flushing 8. (A) What is not the suitable diagnostic tool for CAF? A Electrocardiography B Transesophageal echocardiography C Ultrafast computed tomography D Coronary angiography. 9. (C) What is the most appropriated treatment in a patient with a small CAF (Qp/Qs=1.3) complicated with infective endocarditis? A Complete antibiotics course only B Long term diuretics usage after complete antibiotics course, no surgery C Surgical ligation after complete antibiotics course D Long term prophylactic antibiotics usage after complete antibiotics course, no surgery 10. (C) A 45 y/o man is admitted due to exertional dyspnea and orthepnea. His symptoms improve after diuretics and intravenous nitroglycerin. His echocardiogram reveals preserved systolic function without significant valvular disease except moderate tricuspid regurgitation. However, moderate pulmonary hypertension is also noted. Coronary angiogram show a CAF and Qp/Qs is 2.3. If you are his primary care physician, what will you do next? A Discharge with diuretics B Discharge with antibiotics C Consult surgeon for fistula ligation D Consult surgeon for heart transplantation. 答案解說 (C) Staphyloccous aureus is the most common pathogen in right side infective endocarditis. Viridans Streptococcus is the most common pathogen in left side infective endocarditis. (B) Brian abscess is not likely as a complication in right side infective endocarditis in patients without right to left shunt. In contrast, right side infective endocarditis usually results in septic pulmonary emboli. As disease progression, empyema and hemoptysis happen in these patients. (D) Right side infective endocarditis, psoas muscle abscess, and visceral abscess are all the possible causes of septic pulmonary emboli. In contrast, left side infective endocarditis without left to right shunt can not result in septic pulmonary emboli. (D) Fever, cough, and hemoptysis are common symptoms of right side infective endocarditis. Janeway lesions are small erythematous or hemorrhagic macular nontender lesions on the palms and soles and are the consequence of septic embolic event. However, they occur in left side infective endocarditis. (D ) Pulmonary valve is the least valve involving infective endocarditis (<5%) (B ) Ventricular septal defect, bicuspid aortic valve, and patent ductus arteriosus are all the common predisposing factors of infective endocarditis. (D) Most patients with congenital coronary artery fistula (CAF) have no symptoms. Congestive heart failure and angina occurred in approximately 20% of patients, respectively. (A) Angiography is the traditional method used for the definite diagnosis of CAF. Transesophageal echocardiography and ultrafast computed tomography could provide more satisfactory images of the origin, course and drainage site of CAF. Furthermore, in contrast to conventional angiography, ultrafast computed tomography provides a more reliable tool to detect coronary vascular anomaly. (C ) Surgical ligation of small CAF is favored for patients with complications, such as bacterial endocarditis. Several reports have demonstrated that surgical management is safe and effective. (C) In this patient, CAF results in pulmonary hypertension and congestive heart failure. Surgical ligation is the most appropriated therapy in this patient.