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Coronary to pulmonary artery fistula detected by transthoracic echocardiography
Volume 129, Number 4 American Heart Journal
REFERENCES
1. Clark EB. Mechanisms in the pathogenesis of congenital heart defects. In: Pierpont ME, Moller JM, eds. The genetics of cardiovascular disease. The Hague: Martinus Nijhoff, 1985. 2. Conley ME, Beckwith JB, Mancer JFK, Tenckhoff LF. The spectrum of the DiGeorge syndrome. J Pediatr 1979;84:883. 3. Felker RE, Cartier MS, Emerson DS, Brown DL. Ultrasound of the fetal thymus. J Ultrasound Med 1989;8:669-73. 4. Catty H. Ultrasound of the normal thymus in the infant: simple method of resolving a clinical dilemma. Br J Radiol 1990;63:737-8. 5. Han BK, Babcock DS, Oestreich AE. Normal thymus in infancy: sonographic characteristics. Radiology 1989;170:471-4.
Coronary to pulmonary artery fistula detected by transthoracic echocardiography Jeffrey D. Kaplan, MD, and Rita F. Redberg, MD, MSc
San Francisco, Calif.
The advent of color-flow Doppler echocardiography has enabled the detection of a wide range of abnormal flow signals in the cardiac chambers and great vessels. Determining the origin of abnormal blood flow can be straightforward in some circumstances and quite challenging in others. Abnormal flow patterns in the pulmonary artery (PA) may be caused by a variety of unusual relations and offers a wide differential diagnosis that may be narrowed by analysis of various color-flow characteristics. We report on two cases of abnormal PA flow detected during transthoracic echocardiography in our laboratory and discuss the differential diagnosis and color-flow Doppler features that support the diagnosis of coronary artery-PA fistula. Case 1. A 25-year-old woman with a history of ventricular septal defect repaired at age 3 underwent transthoracic echocardiography with Doppler for worsening exertional dyspnea. Physical examination revealed normal vital signs, and the cardiac examination was remarkable for a III/VI systolic ejection murmur best heard at the left upper sternal border. The remainder of the examination results were normal. ECG showed normal sinus rhythm, right bundle branch block, and nonspecific ST- and T-wave abnormalities in the precordial leads. The surface echocardiogram showed an unchanged pulmonic valve gradient, and saline solution contrast study results were negative for an intracardiac shunt. An abnormal diastolic flow was noted in the proximal pulmonary artery during color-flow Doppler interrogation in the parasternal short-axis view.
From the Division of Cardiology, University of California. Reprint requests: Rita F. Redberg, MD, MSc, University of California, San Francisco, Division of Cardiology, 505 Parnassus Ave., San Francisco, CA 94143-0214. AM HEARTJ 1995;129:839-40. Copyright © 1995 by Mosby-Year Book, Inc. 0002-8703/95/$3.00 + O 4/4/59835
gaplan and Redberg 839 The jet origin was medial, just distal to and directed toward the pulmonic valve. There was no pulmonic valve insufficiency. Transesophageal echocardiography was performed 3 weeks later to better characterize the abnormal PA flow. The left coronary artery system was Well visualized and demonstrated antegrade flow within normal-caliber vessels. Doppler color imaging at the aortic valve level in the vertical plane showed a small area of diastolic flow originating in the left sinus of Valsalva and traveling toward the proximal PA. Case 2. A 19-year-old man with a history of unrepaired ventricular septal defect diagnosed by cardiac catheterization at age 4 underwent routine follow-up transthoracic echocardiogram. Vital signs were normal, and the physical examination results were significant for a III/VI holosystolic murmur along the left sternal border. Electrocardiogram showed a nonspecific intraventricular conduction delay and was otherwise normal. Echocardiogram demonstrated a moderate-sized ventricular septal defect, mild aortic insufficiency, and normal left ventricular function. An abnormal diastolic flow was noted in the proximal pulmonary artery during color-flow Doppler interrogation in the parasternal short-axis view. The jet origin was lateral, distal to the pulmonic valve, and directed toward the bifurcation of the main PA. There was no pulmonic valve insufficiency. A transesophageal echocardiogram was recommended but refused by the patient. There are several diagnostic possibilities for abnormal flow in the pulmonary artery. Color flow Doppler imaging can be helpful in distinguishing among them and is often more sensitive than pulsed Doppler or two-dimensional echo imaging, although pulsed Doppler and two-dimensional echo imaging provide important complementary information. Patent ductus arteriosus is the most common cause of abnormal diastolic flow in the pulmonary artery. It is suggested by a high-velocity flow signal from the aorta to the pulmonary artery bifurcation, which courses in a retrograde fashion along the lateral wall of the main pulmonary artery in both systole and diastole. The jet can be quite narrow and eccentric. An anomalous origin of the left main coronary artery (less commonly the right coronary artery or both coronary arteries) from the pulmonary trunk can also cause an abnormal flow signal in the pulmonary artery. With time, dilated collaterals develop between the two coronary artery systems, with blood shunted from the right to the left coronary artery and then to the pulmonary trunk. This causes a narrow jet best seen in diastole originating in the pulmonary trunk and directed centrally and/or distally. These lesions are associated with wall motion abnormalities, early myocardial infarction, and death. Coronary fistulas involve the pulmonary trunk in 17 % to 66% of cases. 1, 2 They are~believed to result from accessory coronary arteries that rise from a persistent intratrabecular vascular network that occurs during the normal development of coronary arteries from the aorta. 3, 4 Both sexes are equally affected, and both coronary arteries are involved with nearly equal frequency. The fistulas empty into the venous side in >90 % of cases and are usually small but can be largefi 5 Color flow Doppler echocardiography dem-
840
April 1995 American Heart Journal
gaplan and Redberg
onstrates predominantly diastolic (and often continuous) flow into the pulmonary artery. Depending on the size of the fistula, one or both coronary arteries can be enlarged with or without an anomalous origin. Aortopulmonary collaterals have been reported in patients with pulmonary atresia (in the setting of ventricular septal defect or tetralogy of Fallot) or tuberculosis. Highoutput cardiac failure can result from this abnormal communication of intercostal and bronchial arteries to the pulmonary artery. Acquired lesions also can cause abnormal communications to the pulmonary artery. For example, rupture of a thoracic aortic aneurysm can result in the formation of a fistula to the pulmonary artery. Rarely, chest t r a u m a and thoracic surgery can cause similar sequelae. An aorticopulmonary window is a rare, incomplete division of the aorticopulmonary septum, causing an abnormal communication between the ascending aorta and pulmonary trunk. Flow will be continuous from systole through diastole from the aorta to the pulmonary artery. T h e abnormal flow in the pulmonary artery will be primarily antegrade, in contrast to the retrograde flow expected from a p a t e n t ductus arteriosus. In both cases of abnormal diastolic flow in the pulmonary artery in this report, the color Doppler findings were most consistent with small coronary fistulas. In the first case the transesophageal echocardiogram was helpful in detailing the fistula site and characterizing the normal size, location, and flow p at t ern of the left coronary artery. Features t h a t favored small rather than large fistulas included the absence of a continuous murmur, normal flow and size of the left coronary artery (noted in the first case), and the
absence of complications of large fistulas such as myocardial ischemia, infarction, congestive heart failure, or pulmonary artery hypertension. Current recommendations for small, asymptomatic coronary artery fistulas include medical follow-up and antibiotic prophylaxis for the prevention of infective endarteritis. 4 Although both of our patients had ventricular septal defects, increased frequency of coronary artery fistulas has not been reported in patients with ventricular septal defects. In conclusion, we present two cases of abnormal diastolic flow in the pulmonary artery detected by routine color flow Doppler interrogation of the pulmonary artery trunk. Th e flow patterns in both cases are most consistent with small coronary artery fistulas. Despite a large number of possible causes, knowledge of color-flow Doppler characteristics in the pulmonary artery can be helpful in establishing a likely diagnosis with transthoracic echocardiography. Confirmation relies principally on transesophageal echocardiography and/or arteriography.
REFERENCES
1. Hobbs RE, Millit HED, Raghavan PV, et al. Coronary artery fistulae: a 10-year review. CleveClin Q 1982;49:191-7. 2. Levin DC, FellowsKE, Abrams HL. Hemodynamicallysignificantprimary anomalies of the coronary arteries. Circulation 1978;58:25. 3. GobelFL, Anderson CF, BaltxeHA, et al. Shunts between the coronary and pulmonary arteries with normal originof the coronaryarteries. Am J Cardiol 1970;25:655-61. 4. Cheitlin MD. Coronary arterial anomalies. In: Parmley WW, Chatterjee K. Cardiology.Philadelphia, Lippincott, t989:9-11. 5. Child J. Echo Doppler and color-flowimagingin congenital heart disease. Cardiol Clin 1990;8:289-313.
AVAILABILITYOF JOURNALBACK ISSUES As a serviceto our subscribers, copiesof back issues of the AMERICANHEART JOURNALfor the preceding5 years are maintained and are availablefor purchase from the publisher, Mosby, at a cost of $10.00 per issue. The followingquantity discounts are available: 25% off on quantities of 12 to 23, and one-third off on quantities of 24 or more. Please write to Mosby-Year Book, Inc., Subscription Services, 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, or call (800)453-4351 or (314)453-4351 for information on availabilityof particular issues. If unavailable from the publisher, photocopies of complete issues are availablefrom University MicrofilmsInternational, 300 N. Zeeb Rd., Ann Arbor, MI 48106, (313)761-4700.
REFERENCES
1. Clark EB. Mechanisms in the pathogenesis of congenital heart defects. In: Pierpont ME, Moller JM, eds. The genetics of cardiovascular disease. The Hague: Martinus Nijhoff, 1985. 2. Conley ME, Beckwith JB, Mancer JFK, Tenckhoff LF. The spectrum of the DiGeorge syndrome. J Pediatr 1979;84:883. 3. Felker RE, Cartier MS, Emerson DS, Brown DL. Ultrasound of the fetal thymus. J Ultrasound Med 1989;8:669-73. 4. Catty H. Ultrasound of the normal thymus in the infant: simple method of resolving a clinical dilemma. Br J Radiol 1990;63:737-8. 5. Han BK, Babcock DS, Oestreich AE. Normal thymus in infancy: sonographic characteristics. Radiology 1989;170:471-4.
Coronary to pulmonary artery fistula detected by transthoracic echocardiography Jeffrey D. Kaplan, MD, and Rita F. Redberg, MD, MSc
San Francisco, Calif.
The advent of color-flow Doppler echocardiography has enabled the detection of a wide range of abnormal flow signals in the cardiac chambers and great vessels. Determining the origin of abnormal blood flow can be straightforward in some circumstances and quite challenging in others. Abnormal flow patterns in the pulmonary artery (PA) may be caused by a variety of unusual relations and offers a wide differential diagnosis that may be narrowed by analysis of various color-flow characteristics. We report on two cases of abnormal PA flow detected during transthoracic echocardiography in our laboratory and discuss the differential diagnosis and color-flow Doppler features that support the diagnosis of coronary artery-PA fistula. Case 1. A 25-year-old woman with a history of ventricular septal defect repaired at age 3 underwent transthoracic echocardiography with Doppler for worsening exertional dyspnea. Physical examination revealed normal vital signs, and the cardiac examination was remarkable for a III/VI systolic ejection murmur best heard at the left upper sternal border. The remainder of the examination results were normal. ECG showed normal sinus rhythm, right bundle branch block, and nonspecific ST- and T-wave abnormalities in the precordial leads. The surface echocardiogram showed an unchanged pulmonic valve gradient, and saline solution contrast study results were negative for an intracardiac shunt. An abnormal diastolic flow was noted in the proximal pulmonary artery during color-flow Doppler interrogation in the parasternal short-axis view.
From the Division of Cardiology, University of California. Reprint requests: Rita F. Redberg, MD, MSc, University of California, San Francisco, Division of Cardiology, 505 Parnassus Ave., San Francisco, CA 94143-0214. AM HEARTJ 1995;129:839-40. Copyright © 1995 by Mosby-Year Book, Inc. 0002-8703/95/$3.00 + O 4/4/59835
gaplan and Redberg 839 The jet origin was medial, just distal to and directed toward the pulmonic valve. There was no pulmonic valve insufficiency. Transesophageal echocardiography was performed 3 weeks later to better characterize the abnormal PA flow. The left coronary artery system was Well visualized and demonstrated antegrade flow within normal-caliber vessels. Doppler color imaging at the aortic valve level in the vertical plane showed a small area of diastolic flow originating in the left sinus of Valsalva and traveling toward the proximal PA. Case 2. A 19-year-old man with a history of unrepaired ventricular septal defect diagnosed by cardiac catheterization at age 4 underwent routine follow-up transthoracic echocardiogram. Vital signs were normal, and the physical examination results were significant for a III/VI holosystolic murmur along the left sternal border. Electrocardiogram showed a nonspecific intraventricular conduction delay and was otherwise normal. Echocardiogram demonstrated a moderate-sized ventricular septal defect, mild aortic insufficiency, and normal left ventricular function. An abnormal diastolic flow was noted in the proximal pulmonary artery during color-flow Doppler interrogation in the parasternal short-axis view. The jet origin was lateral, distal to the pulmonic valve, and directed toward the bifurcation of the main PA. There was no pulmonic valve insufficiency. A transesophageal echocardiogram was recommended but refused by the patient. There are several diagnostic possibilities for abnormal flow in the pulmonary artery. Color flow Doppler imaging can be helpful in distinguishing among them and is often more sensitive than pulsed Doppler or two-dimensional echo imaging, although pulsed Doppler and two-dimensional echo imaging provide important complementary information. Patent ductus arteriosus is the most common cause of abnormal diastolic flow in the pulmonary artery. It is suggested by a high-velocity flow signal from the aorta to the pulmonary artery bifurcation, which courses in a retrograde fashion along the lateral wall of the main pulmonary artery in both systole and diastole. The jet can be quite narrow and eccentric. An anomalous origin of the left main coronary artery (less commonly the right coronary artery or both coronary arteries) from the pulmonary trunk can also cause an abnormal flow signal in the pulmonary artery. With time, dilated collaterals develop between the two coronary artery systems, with blood shunted from the right to the left coronary artery and then to the pulmonary trunk. This causes a narrow jet best seen in diastole originating in the pulmonary trunk and directed centrally and/or distally. These lesions are associated with wall motion abnormalities, early myocardial infarction, and death. Coronary fistulas involve the pulmonary trunk in 17 % to 66% of cases. 1, 2 They are~believed to result from accessory coronary arteries that rise from a persistent intratrabecular vascular network that occurs during the normal development of coronary arteries from the aorta. 3, 4 Both sexes are equally affected, and both coronary arteries are involved with nearly equal frequency. The fistulas empty into the venous side in >90 % of cases and are usually small but can be largefi 5 Color flow Doppler echocardiography dem-
840
April 1995 American Heart Journal
gaplan and Redberg
onstrates predominantly diastolic (and often continuous) flow into the pulmonary artery. Depending on the size of the fistula, one or both coronary arteries can be enlarged with or without an anomalous origin. Aortopulmonary collaterals have been reported in patients with pulmonary atresia (in the setting of ventricular septal defect or tetralogy of Fallot) or tuberculosis. Highoutput cardiac failure can result from this abnormal communication of intercostal and bronchial arteries to the pulmonary artery. Acquired lesions also can cause abnormal communications to the pulmonary artery. For example, rupture of a thoracic aortic aneurysm can result in the formation of a fistula to the pulmonary artery. Rarely, chest t r a u m a and thoracic surgery can cause similar sequelae. An aorticopulmonary window is a rare, incomplete division of the aorticopulmonary septum, causing an abnormal communication between the ascending aorta and pulmonary trunk. Flow will be continuous from systole through diastole from the aorta to the pulmonary artery. T h e abnormal flow in the pulmonary artery will be primarily antegrade, in contrast to the retrograde flow expected from a p a t e n t ductus arteriosus. In both cases of abnormal diastolic flow in the pulmonary artery in this report, the color Doppler findings were most consistent with small coronary fistulas. In the first case the transesophageal echocardiogram was helpful in detailing the fistula site and characterizing the normal size, location, and flow p at t ern of the left coronary artery. Features t h a t favored small rather than large fistulas included the absence of a continuous murmur, normal flow and size of the left coronary artery (noted in the first case), and the
absence of complications of large fistulas such as myocardial ischemia, infarction, congestive heart failure, or pulmonary artery hypertension. Current recommendations for small, asymptomatic coronary artery fistulas include medical follow-up and antibiotic prophylaxis for the prevention of infective endarteritis. 4 Although both of our patients had ventricular septal defects, increased frequency of coronary artery fistulas has not been reported in patients with ventricular septal defects. In conclusion, we present two cases of abnormal diastolic flow in the pulmonary artery detected by routine color flow Doppler interrogation of the pulmonary artery trunk. Th e flow patterns in both cases are most consistent with small coronary artery fistulas. Despite a large number of possible causes, knowledge of color-flow Doppler characteristics in the pulmonary artery can be helpful in establishing a likely diagnosis with transthoracic echocardiography. Confirmation relies principally on transesophageal echocardiography and/or arteriography.
REFERENCES
1. Hobbs RE, Millit HED, Raghavan PV, et al. Coronary artery fistulae: a 10-year review. CleveClin Q 1982;49:191-7. 2. Levin DC, FellowsKE, Abrams HL. Hemodynamicallysignificantprimary anomalies of the coronary arteries. Circulation 1978;58:25. 3. GobelFL, Anderson CF, BaltxeHA, et al. Shunts between the coronary and pulmonary arteries with normal originof the coronaryarteries. Am J Cardiol 1970;25:655-61. 4. Cheitlin MD. Coronary arterial anomalies. In: Parmley WW, Chatterjee K. Cardiology.Philadelphia, Lippincott, t989:9-11. 5. Child J. Echo Doppler and color-flowimagingin congenital heart disease. Cardiol Clin 1990;8:289-313.
AVAILABILITYOF JOURNALBACK ISSUES As a serviceto our subscribers, copiesof back issues of the AMERICANHEART JOURNALfor the preceding5 years are maintained and are availablefor purchase from the publisher, Mosby, at a cost of $10.00 per issue. The followingquantity discounts are available: 25% off on quantities of 12 to 23, and one-third off on quantities of 24 or more. Please write to Mosby-Year Book, Inc., Subscription Services, 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, or call (800)453-4351 or (314)453-4351 for information on availabilityof particular issues. If unavailable from the publisher, photocopies of complete issues are availablefrom University MicrofilmsInternational, 300 N. Zeeb Rd., Ann Arbor, MI 48106, (313)761-4700.