International Journal of Cardiology 172 (2014) e172–e174
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
Anomalous left anterior descending coronary artery from the pulmonary artery — The role of cardiac MRI Madhusudan Ganigara a,b,⁎, Nick Collins c, David Tanous a,d, David Celermajer a,e, Rajesh Puranik a,e a
The University of Sydney, Faculty of Medicine, Sydney, Australia The Children's Hospital at Westmead, Department of Cardiology, Sydney, Australia Cardiovascular Unit, John Hunter Hospital, Newcastle, Australia d Westmead Hospital, Department of Cardiology, Sydney, Australia e Royal Prince Alfred Hospital, Department of Cardiology, Sydney, Australia b c
a r t i c l e
i n f o
Article history: Received 10 October 2013 Accepted 22 December 2013 Available online 30 December 2013 Keywords: Anomalous coronary artery Delayed enhancement magnetic resonance imaging Myocardial viability
A previously well 37-year-old female presented with subacute onset of mild exertional dyspnea during the second trimester of pregnancy. Physical examination revealed a continuous murmur at the mid-left sternal border with no additional features of cardiac failure or pulmonary hypertension. Transthoracic echocardiography demonstrated a moderately dilated left ventricle with normal systolic function. A dilated and tortuous right coronary artery (RCA) was also noted, characterized by prominent color flow within the interventricular septum, raising suspicion of a coronary artery fistula. The patient proceeded to an uneventful pregnancy and delivery. Subsequent cardiac catheterization, at several months post-partum, revealed a large RCA arising from the right aortic sinus with extensive large caliber collateral vessels retrogradely supplying the left anterior descending coronary artery (LADA) and later opacifying the main pulmonary artery. The left circumflex coronary artery (LCXA) was poorly visualized [Fig. 1A]. Cardiovascular MRI (CMR) was performed using a 1.5T MR scanner. The CMR examination included standard steady-state free precession (SSFP) cine imaging, breath-held fat suppressed 3-dimensional steady-state free precession pulse sequence in
⁎ Corresponding author at: Department of Cardiology, The Children's Hospital at Westmead, Westmead, NSW 2145, Australia. Tel.: + 61 295571464; fax: + 61 s295570618. E-mail address: [email protected] (M. Ganigara). 0167-5273/$ – see front matter © 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijcard.2013.12.056
diastole, gadolinium-enhanced 3-dimensional gradient echo sequences for MR angiography, post-gadolinium delayed myocardial enhancement imaging and velocity-encoded phase-contrast imaging for flow through the great vessels which allowed for shunt calculations. CMR identified a moderately dilated left ventricle with anteroseptal wall hypokinesia and an ejection fraction of 57%. Coronary artery MR imaging revealed a dilated LADA arising anomalously from the left side of the main pulmonary artery. The RCA and the LCXA originated in the usual manner from the right and left aortic sinuses respectively. The RCA was dilated and had a tortuous course providing multiple collateral vessels to the LADA coronary artery system. The LCXA was normally sized and was also noted to be supplying collateral vessels. The pulmonary to systemic blood flow ratio (Qp/Qs) measured 1.2. Delayed gadolinium-enhanced imaging demonstrated subendocardial hyper-enhancement in the basal anteroseptal left ventricular wall consistent with extensive partial thickness infarction [Figs. 1B, C, 2]. Anomalous LADA from the pulmonary artery is a variant of the more common anomalous origin of the left main coronary trunk from the pulmonary artery (ALCAPA) and accounts for less than 0.5% of all congenital heart defects [1]. Survival into adulthood is common because of the normal origin of the two other major epicardial coronary arteries. Coronary angiography is the gold standard imaging modality for coronary anomalies. However, pulmonary artery angiography may not always reveal an anomalous origin of the left coronary artery, as in the present case, because of lack of antegrade flow [2]. While highresolution contrast enhanced CT is another sensitive test that can be used for the diagnosis, this involves exposure to ionizing radiation and does not always provide functional information or allow assessment of myocardial viability. The present case highlights the importance of multimodality imaging in the diagnosis of coronary artery anomalies. Echocardiography and coronary angiography are generally sufficient to confirm the diagnosis. As an adjunctive modality, CMR provides accurate delineation of the proximal coronary artery course via high-resolution (1.5–2 mm) 3-dimensional imaging, specifically detailing the relationship to the great vessels. Further, CMR provides additional data including robust functional information, degree of left-to-right shunt, myocardial perfusion and viability assessment [3] with good correlation to modalities such as PET imaging [4] and without the need for ionizing radiation. In
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Fig. 1. A. Selective right coronary angiogram showing dilated right coronary artery supplying collaterals to left anterior descending coronary artery. B. Breath-held fat suppressed 3dimensional steady-state free precession pulse sequence in diastole demonstrating an enlarged right coronary artery and a normal sized left circumflex coronary artery with conventional origin from the right and left coronary sinuses, respectively. C. Breath-held fat suppressed 3-dimensional steady-state free precession pulse sequence in diastole demonstrating an enlarged left anterior descending coronary artery arising from the left and posterior aspect of the pulmonary artery.
Fig. 2. A. Two-dimensional axial fast-cine phase contrast magnitude image showing the ascending aorta and the pulmonary artery. The left anterior descending coronary artery arises from the left and posterior aspect of the pulmonary artery. B. Two-dimensional axial fast-cine phase contrast velocity encoded image in the same plane as a, demonstrating diastolic flow from the left anterior descending coronary artery into the main pulmonary artery. C. Steady-state free precession image showing the left ventricle in the short axis. D. Corresponding delayed post-gadolinium enhanced image as c, showing partial thickness infarction in the left anterior descending coronary artery territory. The extent of hyperenhanced myocardium is less than 25% transmurality, which indicates predominantly viable myocardium.
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M. Ganigara et al. / International Journal of Cardiology 172 (2014) e172–e174
view of these attributes, CMR imaging should be considered in all patients with coronary anomalies who present late, for diagnostic and prognostic reasons. References [1] Angelini P, Velasco JA, Flamm S. Coronary anomalies: incidence, pathophysiology, and clinical relevance. Circulation 2002;105:2449–54.
[2] Schmitt R, Froehner S, Brunn J, et al. Congenital anomalies of the coronary arteries: imaging with contrast-enhanced, multidetector computed tomography. Eur Radiol 2005;15:1110–21. [3] Corno AF, Festa P. Anomalous coronary arteries. Congenital heart defects. Decision making for cardiac surgery. Volume 3 CT-scan and MRISteinkopff Verlag; 2009. p. 176–83. [4] Parkka JP, Niemi P, Saraste A, et al. Comparison of MRI and positron emission tomography for measuring myocardial perfusion reserve in healthy humans. Magn Reson Imaging 2006;55:772–9.
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
Anomalous left anterior descending coronary artery from the pulmonary artery — The role of cardiac MRI Madhusudan Ganigara a,b,⁎, Nick Collins c, David Tanous a,d, David Celermajer a,e, Rajesh Puranik a,e a
The University of Sydney, Faculty of Medicine, Sydney, Australia The Children's Hospital at Westmead, Department of Cardiology, Sydney, Australia Cardiovascular Unit, John Hunter Hospital, Newcastle, Australia d Westmead Hospital, Department of Cardiology, Sydney, Australia e Royal Prince Alfred Hospital, Department of Cardiology, Sydney, Australia b c
a r t i c l e
i n f o
Article history: Received 10 October 2013 Accepted 22 December 2013 Available online 30 December 2013 Keywords: Anomalous coronary artery Delayed enhancement magnetic resonance imaging Myocardial viability
A previously well 37-year-old female presented with subacute onset of mild exertional dyspnea during the second trimester of pregnancy. Physical examination revealed a continuous murmur at the mid-left sternal border with no additional features of cardiac failure or pulmonary hypertension. Transthoracic echocardiography demonstrated a moderately dilated left ventricle with normal systolic function. A dilated and tortuous right coronary artery (RCA) was also noted, characterized by prominent color flow within the interventricular septum, raising suspicion of a coronary artery fistula. The patient proceeded to an uneventful pregnancy and delivery. Subsequent cardiac catheterization, at several months post-partum, revealed a large RCA arising from the right aortic sinus with extensive large caliber collateral vessels retrogradely supplying the left anterior descending coronary artery (LADA) and later opacifying the main pulmonary artery. The left circumflex coronary artery (LCXA) was poorly visualized [Fig. 1A]. Cardiovascular MRI (CMR) was performed using a 1.5T MR scanner. The CMR examination included standard steady-state free precession (SSFP) cine imaging, breath-held fat suppressed 3-dimensional steady-state free precession pulse sequence in
⁎ Corresponding author at: Department of Cardiology, The Children's Hospital at Westmead, Westmead, NSW 2145, Australia. Tel.: + 61 295571464; fax: + 61 s295570618. E-mail address: [email protected] (M. Ganigara). 0167-5273/$ – see front matter © 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijcard.2013.12.056
diastole, gadolinium-enhanced 3-dimensional gradient echo sequences for MR angiography, post-gadolinium delayed myocardial enhancement imaging and velocity-encoded phase-contrast imaging for flow through the great vessels which allowed for shunt calculations. CMR identified a moderately dilated left ventricle with anteroseptal wall hypokinesia and an ejection fraction of 57%. Coronary artery MR imaging revealed a dilated LADA arising anomalously from the left side of the main pulmonary artery. The RCA and the LCXA originated in the usual manner from the right and left aortic sinuses respectively. The RCA was dilated and had a tortuous course providing multiple collateral vessels to the LADA coronary artery system. The LCXA was normally sized and was also noted to be supplying collateral vessels. The pulmonary to systemic blood flow ratio (Qp/Qs) measured 1.2. Delayed gadolinium-enhanced imaging demonstrated subendocardial hyper-enhancement in the basal anteroseptal left ventricular wall consistent with extensive partial thickness infarction [Figs. 1B, C, 2]. Anomalous LADA from the pulmonary artery is a variant of the more common anomalous origin of the left main coronary trunk from the pulmonary artery (ALCAPA) and accounts for less than 0.5% of all congenital heart defects [1]. Survival into adulthood is common because of the normal origin of the two other major epicardial coronary arteries. Coronary angiography is the gold standard imaging modality for coronary anomalies. However, pulmonary artery angiography may not always reveal an anomalous origin of the left coronary artery, as in the present case, because of lack of antegrade flow [2]. While highresolution contrast enhanced CT is another sensitive test that can be used for the diagnosis, this involves exposure to ionizing radiation and does not always provide functional information or allow assessment of myocardial viability. The present case highlights the importance of multimodality imaging in the diagnosis of coronary artery anomalies. Echocardiography and coronary angiography are generally sufficient to confirm the diagnosis. As an adjunctive modality, CMR provides accurate delineation of the proximal coronary artery course via high-resolution (1.5–2 mm) 3-dimensional imaging, specifically detailing the relationship to the great vessels. Further, CMR provides additional data including robust functional information, degree of left-to-right shunt, myocardial perfusion and viability assessment [3] with good correlation to modalities such as PET imaging [4] and without the need for ionizing radiation. In
M. Ganigara et al. / International Journal of Cardiology 172 (2014) e172–e174
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Fig. 1. A. Selective right coronary angiogram showing dilated right coronary artery supplying collaterals to left anterior descending coronary artery. B. Breath-held fat suppressed 3dimensional steady-state free precession pulse sequence in diastole demonstrating an enlarged right coronary artery and a normal sized left circumflex coronary artery with conventional origin from the right and left coronary sinuses, respectively. C. Breath-held fat suppressed 3-dimensional steady-state free precession pulse sequence in diastole demonstrating an enlarged left anterior descending coronary artery arising from the left and posterior aspect of the pulmonary artery.
Fig. 2. A. Two-dimensional axial fast-cine phase contrast magnitude image showing the ascending aorta and the pulmonary artery. The left anterior descending coronary artery arises from the left and posterior aspect of the pulmonary artery. B. Two-dimensional axial fast-cine phase contrast velocity encoded image in the same plane as a, demonstrating diastolic flow from the left anterior descending coronary artery into the main pulmonary artery. C. Steady-state free precession image showing the left ventricle in the short axis. D. Corresponding delayed post-gadolinium enhanced image as c, showing partial thickness infarction in the left anterior descending coronary artery territory. The extent of hyperenhanced myocardium is less than 25% transmurality, which indicates predominantly viable myocardium.
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M. Ganigara et al. / International Journal of Cardiology 172 (2014) e172–e174
view of these attributes, CMR imaging should be considered in all patients with coronary anomalies who present late, for diagnostic and prognostic reasons. References [1] Angelini P, Velasco JA, Flamm S. Coronary anomalies: incidence, pathophysiology, and clinical relevance. Circulation 2002;105:2449–54.
[2] Schmitt R, Froehner S, Brunn J, et al. Congenital anomalies of the coronary arteries: imaging with contrast-enhanced, multidetector computed tomography. Eur Radiol 2005;15:1110–21. [3] Corno AF, Festa P. Anomalous coronary arteries. Congenital heart defects. Decision making for cardiac surgery. Volume 3 CT-scan and MRISteinkopff Verlag; 2009. p. 176–83. [4] Parkka JP, Niemi P, Saraste A, et al. Comparison of MRI and positron emission tomography for measuring myocardial perfusion reserve in healthy humans. Magn Reson Imaging 2006;55:772–9.
