Can TTE Diagnose Right Pulmonary Artery‐to‐Left Atrial Fistula? A Rare Case Report and Literature Review

Abstract

Key words: right pulmonary artery-to-left atrial fistula, congenital heart disease, transthoracic echocardiography Case Report: A 10-year-old girl was referred to our hospital in 2014 for lip cyanosis after birth. With normal physical development, the only positive clinical symptom in the patient was cyanosis in the lip, fingers, and toes. Laboratory examinations reveal low oxygen saturation (68%) and a significantly increased hemoglobin content of 254 g/L. Several previous echocardiography examinations in other hospitals did not indicate any specific diagnosis.A systemic echocardiographic examination was performed on the patient with special attention paid to the position and connection of the vessels, including the aorta, pulmonary arteries (PA), superior and inferior vena cava, and pulmonary veins. In the left ventricular long axis, an enlargement of the left atrium (LA) and left ventricle (LV) with a thickened left ventricular wall was observed. In the short-axis view of the aorta, dilation of the right PA(RPA) and an abnormal branch originating from the posterior wall of the RPA were observed (Fig. 1A). The abnormal branch was 17 mm distal to the bifurcation of the PA with a diameter of 10 mm. When the view was changed to the high pulmonary artery longaxis view, a fistula from the RPA to the posterior wall of the LA was observed (Fig. 1B). Color Doppler revealed a right-to-left shunt flow through the fistula, and pulsed Doppler revealed a systolic and diastolic dual-phase spectrum with a peak flow velocity of 145 cm/sec at systole (Fig. 1C,D).Computerized tomography angiography with three-dimensional reconstruction was acquired, and the large tortuous communication between the RPA and LA was confirmed ( Fig. 2A,B).The patient underwent surgical operation, and the imaging diagnosis was confirmed by surgical findings. After ligation and resection of the fistula, the blood oxygen saturation increased to 96% immediately, and the postoperative followup at 10 months indicated no operative-related complications. Discussion and Literature Review:PA-LAF is a very rare heart disease. Fewer than 100 cases have been reported since the first case was described by Friedlich in 1950, 1 and the incidence remains unclear. The male-to-female ratio is approximately 3:1 according to a literature review (through the year 2000), which revealed 51 reported cases. 2 Most of the cases were congenital, but a small number of cases were caused by injury. 3 The most important clinical manifestations were unexplainable central cyanosis and hypoxemia. In addition, because a portion of the pulmonary blood flows directly to the LA via the fistula without filtration by the lung, arterial emboli and brain abscesses represent the most important complications of PA-LAF. Surgery before heart failure may be the most effective treatment for this abnormality. However, Zeebregst reported that the mortality rate of surgery cases was nearly 22% from 1950 to 1979, and the primary causes of death were associated with pulmonary embolism, bleeding, and he...

Fistula between the right pulmonary artery and the left atrium coexisting with a secundum‐type atrial septal defect: An unusual case of cyanosis in a girl

“…Moreover, these fistulas may undergo aneurysmal growth and pose the risk of fatal rupture if left untreated. Surgical correction soon after diagnosis is recommended with the expectation of returning to normal cardiovascular status . Traditional treatment involves closing the abnormal communication with surgical ligation through median sternotomy or video‐thoracoscopic.…”

“…of returning to normal cardiovascular status. [2][3][4][5][6][7][8]12,13 Traditional treatment involves closing the abnormal communication with surgical ligation through median sternotomy or video-thoracoscopic. However, this operation is associated with high risk, massive trauma, and various complications, such as systemic embolism, infective endarteritis, and cerebral abscess, as well as the rupture of aneurysmal communications.…”

“…3,4 Diagnosing this anomaly is difficult, and multi-instrumental approaches, such as echocardiography, CT, and cardiac catheterization, are necessary to confirm this unusual diagnosis. 5,6 Here, we present a case of a fistula between the right PA (RPA) and the LA with secundum-type atrial septal defect (ASD) and its management.…”

“…Such patients usually present with central cyanosis, clubbing, dyspnea, or uncommonly with complications of systemic embolism or cerebral abscess . Diagnosing this anomaly is difficult, and multi‐instrumental approaches, such as echocardiography, CT, and cardiac catheterization, are necessary to confirm this unusual diagnosis . Here, we present a case of a fistula between the right PA (RPA) and the LA with secundum‐type atrial septal defect (ASD) and its management.…”