Legal Medicine 16 (2014) 84–88
Contents lists available at ScienceDirect
Legal Medicine journal homepage: www.elsevier.com/locate/legalmed
Case report
Anomalous origin of the right coronary artery from the pulmonary artery: An autopsied sudden death case with severe atherosclerotic disease of the left coronary artery T. Nagai a,e, T. Mukai a,e, S. Takahashi b,e, A. Takada b,e,⇑, K. Saito c,e, K. Harada d,e, S. Mori e, N. Abe e a
Department of Legal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan Department of Forensic Medicine, Saitama Medical University, Saitama, Japan Department of Forensic Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan d Department of Forensic Medicine, National Defense Medical College, Saitama, Japan e Tokyo Medical Examiner’s Office, Tokyo, Japan b c
a r t i c l e
i n f o
Article history: Received 28 October 2013 Received in revised form 26 November 2013 Accepted 28 November 2013 Available online 8 December 2013 Keywords: Coronary anomaly Atherosclerosis Ischemic heart disease Sudden death Forensic pathology
a b s t r a c t Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare anomaly. It may contribute to myocardial ischemia or sudden death, although the lesion is usually asymptomatic. We report a sudden death case of a 58-year-old man with ARCAPA coexisting with severe atherosclerotic coronary artery disease. He had been healthy until he complained of chest pain, several days before death, despite the discovery of heart murmur in childhood and suspicion of valvular heart disease. The autopsy revealed not only typical findings of the right coronary anomaly with well-developed collateral circulations but also severe atherosclerotic lesions of the left coronary artery, and ischemic change of the myocardium in the left and right coronary arterial perfusion territory. In addition to the ‘‘coronary steal’’ phenomenon primarily caused by ARCAPA, the reduced flow of both coronary arteries and further increase of ‘‘coronary steal’’ due to atherosclerotic obstructive coronary disease might have contributed to the patient’s death. Ó 2013 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital anomaly with about 100 cases reported in the literature to date [1–4]. Most are discovered as incidental findings at autopsy, angiographic examination or surgical operation [1,3]. ARCAPA may lead to myocardial ischemia, cardiac arrest or sudden death, although most patients are asymptomatic [1,5–7]. We describe an autopsied sudden-death case of ARCAPA with severe atherosclerotic disease of the left coronary artery and discuss the contribution of atherosclerosis to the patient’s death. 2. Case report 2.1. Case history A 58-year-old man was found with cardiac arrest in his car, which had collided with a guardrail. He was immediately ⇑ Corresponding author. Address: Department of Forensic Medicine, Saitama Medical University, Morohongo 38, Moroyama-cho, Iruma-gun, Saitama 350-0495, Japan. Tel.: +81 492 276 1177. E-mail address: [email protected] (A. Takada). 1344-6223/$ - see front matter Ó 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.legalmed.2013.11.007
transported to an emergency hospital, but could not be resuscitated. He had been healthy until complaining of chest pain several days before death, despite the discovery of heart murmur in his childhood and suspicion of valvular heart disease. We could not obtain enough information about the patient’s history to identify coronary risk factors, but did note that he was a heavy smoker (40 cigarettes a day).
2.2. Autopsy findings The heart (right coronary dominance) weighed 440 g. The right coronary artery (RCA) arose from the right sinus of the pulmonary trunk with normal distribution, and was dilated (1.0 cm maximum in caliber) with thin walls macroscopically showing a vein-like character (Figs. 1a, 2a and 3). The left coronary artery (LCA), which was normally originated and distributed was quite dilated (1.3 cm maximum in caliber) and tortuous (Figs. 1b and 2b). Severe atherosclerotic lesions were revealed in the left anterior descending artery (LAD), the left circumflex artery (LCx), and diagonal branches with 90%, 75% and 75% stenosis, respectively. The most stenotic lesion of the LAD was in the near-distal portion of the first septal branch: the LAD proximal to the stenosis showed marked dilatation with a partly aneurysmal appearance (Fig. 4).
T. Nagai et al. / Legal Medicine 16 (2014) 84–88
Fig. 1a. The right coronary artery (arrow) arises from the pulmonary artery (PA) with normal distribution, but is dilated with a thin walled, vein-like looks.
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Fig. 2a. The ostium of the right coronary artery (RCA) exists in the right anterior sinus of the pulmonary artery (PA).
Fig. 2b. The ostium of the left coronary artery exists in the left sinus of Valsalva, as is normal.
Fig. 1b. The left coronary artery is markedly dilated and tortuous.
Many gross anastomotic vessels (collateral circulations) between the left and right coronary arteries were observed to have formed via the conus, and the right ventricular, interventricular septal, distal left anterior descending, obtuse marginal and diagonal branches (0.2–0.4 cm in caliber). No anastomotic vessels from the proximal portion of the LCx to the RCA developed. Massive subendocardial (inner third or half of myocardium) fibroses were found in the antero- and posteroseptal wall of the left ventricle. Acute myocardial infarction was not evident. Subendocardial vascular dilatation in the trabeculae carneae of both ventricles was remarkable. No valvular lesion was found except opaqueness of the mitral valve leaflets with slight atheromatous plaques. There were no other congenital cardiac anomalies.
Fig. 3. Macroscopic view of transverse sections of the right coronary artery with a thin-walled, vein-like appearance.
Histologically, the aberrant vein-like RCA was arterial in structure with obvious media (Fig. 5a). No atherosclerosis was present in the RCA. Severe atherosclerosis with over 90% stenosis was observed in the LAD (Fig. 5b). There was neither fresh plaque
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T. Nagai et al. / Legal Medicine 16 (2014) 84–88
Fig. 5b. Severe atherosclerotic stenosis of the left anterior descending artery (Elastica Masson-Goldner stain).
Fig. 4. Transverse sections of the left coronary artery. Severe atherosclerotic stenosis of the left anterior descending artery just distal of the first septal branch (arrow) and marked dilatation of the left coronary artery proximal to the lesion are seen.
Fig. 6. A transverse section of the ventricles (Semi-macroscopic view, Azan stain).
The kidneys revealed slight diabetic changes including a diffuse lesion of the glomeruli and a hyalinous sclerosis of the arterioles. The postmortem HbA1c was estimated at 9.5%.
3. Discussion
Fig. 5a. Microscopic view of the right coronary artery (Elastica Masson-Goldner stain).
disruption nor fresh occlusive thrombus formation in the LAD, but recent intraplaque hemorrhage and mural thrombus was found. There were massive or focal fibroses in the myocardium of the left ventricle (Fig. 6). No acute ischemic change was evident. Dilated subendocardial vessels in the left ventricle had a sinusoid-like appearance, while those in the right ventricle were wall-thickened and artery-like (Figs. 7a and 7b). Connections between sinusoidlike and artery-like vessels were seen in the ventricular septum (Figs. 8a and 8b). The A-V and S-A nodal arteries supplied by the RCA showed histological findings similar to those of the aberrant RCA. Pathological findings suggesting pulmonary hypertension were not observed.
ARCAPA is a rare congenital anomaly first described in 1885 by Brooks [8], having a 0.002% frequency among the adult coronary arteriographic population, and comprising 0.12% of coronary artery anomalies [9]. This anomaly is approximately one-tenth as common as anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) [1,10]. Associated congenital cardiac defects are reported in more than one-third of patients with ARCAPA: namely, aortopulmonary window in 40% and tetralogy of Fallot in 25% [2]. Unlike ALCAPA, which usually manifests the classic syndrome (Bland–White–Garland syndrome) of myocardial ischemia, infarction and/or sudden cardiac death in infancy or early childhood [10–12], ARCAPA often does not manifest until adulthood, because of the lower oxygen demand of the right ventricle and smaller myocardial perfusion territory of the RCA compared with the LCA. The anomaly has been discovered incidentally at autopsy or surgical operation in the past [1], and more recently, has been diagnosed using echocardiography, angiography and electrocardiographically gated computed tomography coronary angiography
T. Nagai et al. / Legal Medicine 16 (2014) 84–88
87
Fig. 7a. Dilated arterial-like vessels in subendocardial region of the right ventricular wall (Elastica Masson-Goldner stain).
Fig. 8a. Dilated vessels of the ventricular septum (Semi-macroscopic view, Elastica Masson-Goldner stain).
Fig. 7b. Dilated sinusoid-like vessels in subendocardial region of the left ventricular wall (Elastica Masson-Goldner stain).
during evaluation for dyspnea, atypical chest pain, angina pectoris or continuous murmur [3–4]. Although most patients are asymptomatic, cardiac arrest or sudden death has been associated with this anomaly [1,5–7]; a crib death of a 2-year-old boy without preceding evidence of any illness [1], cardiac arrests in a 17-year-old girl [6] and a 25-year-old woman [7], and a sudden death of 55-year-old woman [5] have also been reported in the literature. ARCAPA is said to be not benign because the ‘‘coronary arterial steal’’ [13] can result in exercise-induced myocardial ischemia or even sudden death, even in cases without coronary artery disease of the LCA [2,13–15]. Mintz et al. [13] mentioned in his report that ‘‘coronary arterial steal’’ might be the mechanism of exercise-induced myocardial ischemia, even sudden death. In the instance of ARCAPA, blood from the aorta entered the LCA, passed through the collaterals to the RCA, and then drained into the pulmonary trunk in a retrograde manner [10]. Of the Tc-99 m-labeled microspheres injected into the LCA of one ARCAPA patient, 84% passed through the collaterals to the RCA to lodge in the lung, and blood flow through the anomalous RCA was 1200–1400 ml/min toward the pulmonary artery at surgery [13].
Fig. 8b. Connection of arterial-like and vein-like dilated vessels in the septum (Elastica Masson-Goldner stain).
Several other ARCAPA cases like ours, with severe stenosis of the left coronary artery, have been reported [4,16–17], while most adult patients of ARCAPA with angina pectoris, cardiac arrest or sudden death had no atherosclerotic disease of the normally originating left coronary artery [1,5–7]. In ARCAPA with severe atherosclerosis of the LCA, myocardial ischemia of the arterial perfusion territory of both coronaries may become serious because of the reduction of coronary arterial flow due to severe stenosis and the further increase of coronary steal via collaterals more proximal to the obstructive lesion compared with ARCAPA without coronary artery disease.
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T. Nagai et al. / Legal Medicine 16 (2014) 84–88
Cx LAD CA Sep
RVA
RCA RVA
Fig. 9a. Schema of the coronary arterial flow of ARCAPA without atherosclerotic stenosis.
Cx LAD CA
RVA
RCA
Sep
RVA
Fig. 9b. Schema of the coronary arterial flow of ARCAPA with severe atherosclerotic stenosis (w).
In the present case, ARCAPA showing typical morphological findings of RCA anomaly with well-developed collateral circulation, was associated with a severe atherosclerotic lesion in the LCA. The anomalous RCA was dilated, thin-walled and vein-like in character without atherosclerotic lesions. On the other hand, the normally originated and distributed LCA was quite dilated and tortuous with severe atherosclerosis. Furthermore, the LAD showed more than 90% stenosis in the portion just distal of the first septal branch. Well-developed collateral circulations were observed between the left and right coronary arteries and several septal arteries were remarkably increased in caliber. Subendocardial vascular
dilatations mentioned by Cronk et al. [16] were seen. In the present case, these were sinusoid-like in the left ventricle and wall- thickened artery-like in the right ventricle, and connections between those vessels were seen in the ventricular septum, suggesting ‘intercoronary shunting’. Massive subendocardial fibroses in the perfusion territory of the LAD and the RCA, suggesting chronic myocardial ischemia, were seen. The lateral wall was spared from the chronic ischemia because the LCx was relatively patent and did not take off to the collateral circulation to the RCA. In addition to myocardial ischemia due to the coronary steal phenomenon via collateral circulations formed in the patient’s early life (Fig. 9a), severe stenosis of the relatively proximal region of the left anterior descending artery might have worsened the condition (myocardial ischemia) because of reduction of coronary artery flow and may have further increased the coronary steal (Fig. 9b). Furthermore, massive subendocardial fibroses may have become the foci of lethal arrhythmia by a reentrant mechanism [18]. Thus, the sudden death in our case may have been caused by deterioration of the myocardial ischemia due to rare coronary anomaly and severe atherosclerosis, and lethal arrhythmia based on the ischemic lesions of the myocardium. References [1] Lerberg DB, Ogden JA, Zuberbuhler JR, Bahnson HT. Anomalous origin of the right coronary artery from the pulmonary artery. Ann Thorac Surg 1979;27: 87–94. [2] Radke PW, Messmer BJ, Haager PK, Klues HG. Anomaluos origin of the right coronary artery: preoperative and postoperative hemodynamics. Ann Thorac Surg 1998;66:1444–9. [3] Williams IA, Gersony WM, Hellenbrand WE. Anomalous right coronary artery arising from the pulmonary artery: a report of 7 cases and a review of the literature. Am Heart J 2006;152:1004.e9–1004.e17. [4] Kuba PK, Sharma J, Sharma A. Successful surgical treatment of a septuagenarian with anomalous right coronary artery from the pulmonary artery with an eleven year follow-up. Sultan Qaboos Univ Med J 2013;13: 169–74. [5] Pribble RH. Anatomic variations of the coronary arteries and their clinical significance. J Indiana State Med Assoc 1961;54:329–33. [6] Wald S, Stonecipher K, Baldwin BJ, Nutter DO. Anomalous origin of the right coronary artery from the pulmonary artery. Am J Cardiol 1971;27:677–81. [7] Bregman D, Brennan FJ, Singer A, Vinci J, Parodi EN, Cassarella WJ, et al. Anomalous origin of the right coronary artery from the pulmonary artery. J Thorac Cardiovasc Surg 1976;72:626–30. [8] Brooks HSJ. Two cases of an abnormal coronary artery of the heart arising from the pulmonary artery: with some remarks upon the effect of this anomaly in producing cirsoid dilatation of the vessels. J Anat Physiol 1885;20:26–9. [9] Yamanaka O, Hobbs RE. Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Cathet Cardiovasc Diagn 1990;21:28–40. [10] Roberts WC. Major anomalies of coronary arterial origin seen in adulthood. Am Heart J 1986;111:941–63. [11] Edwards JE. The direction of blood flow in coronary arteries arising from the pulmonary trunk. Circulation 1964;29:163–6. [12] Wesselhoeft H, Fawcett JS, Johnson AL. Anomalous origin of the left coronary artery from the pulmonary trunk. Circulation 1968;38:403–25. [13] Mintz GS, Iskandrian AS, Bemis CE, Mundth ED, Owens JS. Myocardial ischemia in anomalous origin of the right coronary artery from the pulmonary trunk. Proof of a coronary steal. Am J Cardiol 1983;51:610–2. [14] Waite S, Ng T, Afari A, Gohari A, Lowery R. CT diagnosis of isolated anomalous origin of the RCA arising from the main pulmonary artery. J Thorac Imaging 2008;23:145–7. [15] Baskurt M, Yyldyz A, Caglar IM, Kylyckesmez K, Okcun B, Ozkan AA, et al. Right coronary artery arising from the pulmonary trunk. Thorac Cardiovasc Surg 2009;57:424–6. [16] Cronk ES, Sinclair JG, Rigdon RH. An anomalous coronary artery arising from the pulmonary artery. Am Heart J 1951;42:906–11. [17] Capuano C, Sesana M, Capuano F, Leonzi O, Cuccia C, Troise G. Right coronary artery arising from the pulmonary trunk. Cardiovasc Revasc Med 2007;8:76–9. [18] Mehta D, Curwin J, Gomes JA, Fuster V. Sudden death in coronary artery disease. Acute ischemia versus myocardial substrate. Circulation 1997;96: 3215–23.
Contents lists available at ScienceDirect
Legal Medicine journal homepage: www.elsevier.com/locate/legalmed
Case report
Anomalous origin of the right coronary artery from the pulmonary artery: An autopsied sudden death case with severe atherosclerotic disease of the left coronary artery T. Nagai a,e, T. Mukai a,e, S. Takahashi b,e, A. Takada b,e,⇑, K. Saito c,e, K. Harada d,e, S. Mori e, N. Abe e a
Department of Legal Medicine, St. Marianna University School of Medicine, Kanagawa, Japan Department of Forensic Medicine, Saitama Medical University, Saitama, Japan Department of Forensic Medicine, Faculty of Medicine, Juntendo University, Tokyo, Japan d Department of Forensic Medicine, National Defense Medical College, Saitama, Japan e Tokyo Medical Examiner’s Office, Tokyo, Japan b c
a r t i c l e
i n f o
Article history: Received 28 October 2013 Received in revised form 26 November 2013 Accepted 28 November 2013 Available online 8 December 2013 Keywords: Coronary anomaly Atherosclerosis Ischemic heart disease Sudden death Forensic pathology
a b s t r a c t Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare anomaly. It may contribute to myocardial ischemia or sudden death, although the lesion is usually asymptomatic. We report a sudden death case of a 58-year-old man with ARCAPA coexisting with severe atherosclerotic coronary artery disease. He had been healthy until he complained of chest pain, several days before death, despite the discovery of heart murmur in childhood and suspicion of valvular heart disease. The autopsy revealed not only typical findings of the right coronary anomaly with well-developed collateral circulations but also severe atherosclerotic lesions of the left coronary artery, and ischemic change of the myocardium in the left and right coronary arterial perfusion territory. In addition to the ‘‘coronary steal’’ phenomenon primarily caused by ARCAPA, the reduced flow of both coronary arteries and further increase of ‘‘coronary steal’’ due to atherosclerotic obstructive coronary disease might have contributed to the patient’s death. Ó 2013 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital anomaly with about 100 cases reported in the literature to date [1–4]. Most are discovered as incidental findings at autopsy, angiographic examination or surgical operation [1,3]. ARCAPA may lead to myocardial ischemia, cardiac arrest or sudden death, although most patients are asymptomatic [1,5–7]. We describe an autopsied sudden-death case of ARCAPA with severe atherosclerotic disease of the left coronary artery and discuss the contribution of atherosclerosis to the patient’s death. 2. Case report 2.1. Case history A 58-year-old man was found with cardiac arrest in his car, which had collided with a guardrail. He was immediately ⇑ Corresponding author. Address: Department of Forensic Medicine, Saitama Medical University, Morohongo 38, Moroyama-cho, Iruma-gun, Saitama 350-0495, Japan. Tel.: +81 492 276 1177. E-mail address: [email protected] (A. Takada). 1344-6223/$ - see front matter Ó 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.legalmed.2013.11.007
transported to an emergency hospital, but could not be resuscitated. He had been healthy until complaining of chest pain several days before death, despite the discovery of heart murmur in his childhood and suspicion of valvular heart disease. We could not obtain enough information about the patient’s history to identify coronary risk factors, but did note that he was a heavy smoker (40 cigarettes a day).
2.2. Autopsy findings The heart (right coronary dominance) weighed 440 g. The right coronary artery (RCA) arose from the right sinus of the pulmonary trunk with normal distribution, and was dilated (1.0 cm maximum in caliber) with thin walls macroscopically showing a vein-like character (Figs. 1a, 2a and 3). The left coronary artery (LCA), which was normally originated and distributed was quite dilated (1.3 cm maximum in caliber) and tortuous (Figs. 1b and 2b). Severe atherosclerotic lesions were revealed in the left anterior descending artery (LAD), the left circumflex artery (LCx), and diagonal branches with 90%, 75% and 75% stenosis, respectively. The most stenotic lesion of the LAD was in the near-distal portion of the first septal branch: the LAD proximal to the stenosis showed marked dilatation with a partly aneurysmal appearance (Fig. 4).
T. Nagai et al. / Legal Medicine 16 (2014) 84–88
Fig. 1a. The right coronary artery (arrow) arises from the pulmonary artery (PA) with normal distribution, but is dilated with a thin walled, vein-like looks.
85
Fig. 2a. The ostium of the right coronary artery (RCA) exists in the right anterior sinus of the pulmonary artery (PA).
Fig. 2b. The ostium of the left coronary artery exists in the left sinus of Valsalva, as is normal.
Fig. 1b. The left coronary artery is markedly dilated and tortuous.
Many gross anastomotic vessels (collateral circulations) between the left and right coronary arteries were observed to have formed via the conus, and the right ventricular, interventricular septal, distal left anterior descending, obtuse marginal and diagonal branches (0.2–0.4 cm in caliber). No anastomotic vessels from the proximal portion of the LCx to the RCA developed. Massive subendocardial (inner third or half of myocardium) fibroses were found in the antero- and posteroseptal wall of the left ventricle. Acute myocardial infarction was not evident. Subendocardial vascular dilatation in the trabeculae carneae of both ventricles was remarkable. No valvular lesion was found except opaqueness of the mitral valve leaflets with slight atheromatous plaques. There were no other congenital cardiac anomalies.
Fig. 3. Macroscopic view of transverse sections of the right coronary artery with a thin-walled, vein-like appearance.
Histologically, the aberrant vein-like RCA was arterial in structure with obvious media (Fig. 5a). No atherosclerosis was present in the RCA. Severe atherosclerosis with over 90% stenosis was observed in the LAD (Fig. 5b). There was neither fresh plaque
86
T. Nagai et al. / Legal Medicine 16 (2014) 84–88
Fig. 5b. Severe atherosclerotic stenosis of the left anterior descending artery (Elastica Masson-Goldner stain).
Fig. 4. Transverse sections of the left coronary artery. Severe atherosclerotic stenosis of the left anterior descending artery just distal of the first septal branch (arrow) and marked dilatation of the left coronary artery proximal to the lesion are seen.
Fig. 6. A transverse section of the ventricles (Semi-macroscopic view, Azan stain).
The kidneys revealed slight diabetic changes including a diffuse lesion of the glomeruli and a hyalinous sclerosis of the arterioles. The postmortem HbA1c was estimated at 9.5%.
3. Discussion
Fig. 5a. Microscopic view of the right coronary artery (Elastica Masson-Goldner stain).
disruption nor fresh occlusive thrombus formation in the LAD, but recent intraplaque hemorrhage and mural thrombus was found. There were massive or focal fibroses in the myocardium of the left ventricle (Fig. 6). No acute ischemic change was evident. Dilated subendocardial vessels in the left ventricle had a sinusoid-like appearance, while those in the right ventricle were wall-thickened and artery-like (Figs. 7a and 7b). Connections between sinusoidlike and artery-like vessels were seen in the ventricular septum (Figs. 8a and 8b). The A-V and S-A nodal arteries supplied by the RCA showed histological findings similar to those of the aberrant RCA. Pathological findings suggesting pulmonary hypertension were not observed.
ARCAPA is a rare congenital anomaly first described in 1885 by Brooks [8], having a 0.002% frequency among the adult coronary arteriographic population, and comprising 0.12% of coronary artery anomalies [9]. This anomaly is approximately one-tenth as common as anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) [1,10]. Associated congenital cardiac defects are reported in more than one-third of patients with ARCAPA: namely, aortopulmonary window in 40% and tetralogy of Fallot in 25% [2]. Unlike ALCAPA, which usually manifests the classic syndrome (Bland–White–Garland syndrome) of myocardial ischemia, infarction and/or sudden cardiac death in infancy or early childhood [10–12], ARCAPA often does not manifest until adulthood, because of the lower oxygen demand of the right ventricle and smaller myocardial perfusion territory of the RCA compared with the LCA. The anomaly has been discovered incidentally at autopsy or surgical operation in the past [1], and more recently, has been diagnosed using echocardiography, angiography and electrocardiographically gated computed tomography coronary angiography
T. Nagai et al. / Legal Medicine 16 (2014) 84–88
87
Fig. 7a. Dilated arterial-like vessels in subendocardial region of the right ventricular wall (Elastica Masson-Goldner stain).
Fig. 8a. Dilated vessels of the ventricular septum (Semi-macroscopic view, Elastica Masson-Goldner stain).
Fig. 7b. Dilated sinusoid-like vessels in subendocardial region of the left ventricular wall (Elastica Masson-Goldner stain).
during evaluation for dyspnea, atypical chest pain, angina pectoris or continuous murmur [3–4]. Although most patients are asymptomatic, cardiac arrest or sudden death has been associated with this anomaly [1,5–7]; a crib death of a 2-year-old boy without preceding evidence of any illness [1], cardiac arrests in a 17-year-old girl [6] and a 25-year-old woman [7], and a sudden death of 55-year-old woman [5] have also been reported in the literature. ARCAPA is said to be not benign because the ‘‘coronary arterial steal’’ [13] can result in exercise-induced myocardial ischemia or even sudden death, even in cases without coronary artery disease of the LCA [2,13–15]. Mintz et al. [13] mentioned in his report that ‘‘coronary arterial steal’’ might be the mechanism of exercise-induced myocardial ischemia, even sudden death. In the instance of ARCAPA, blood from the aorta entered the LCA, passed through the collaterals to the RCA, and then drained into the pulmonary trunk in a retrograde manner [10]. Of the Tc-99 m-labeled microspheres injected into the LCA of one ARCAPA patient, 84% passed through the collaterals to the RCA to lodge in the lung, and blood flow through the anomalous RCA was 1200–1400 ml/min toward the pulmonary artery at surgery [13].
Fig. 8b. Connection of arterial-like and vein-like dilated vessels in the septum (Elastica Masson-Goldner stain).
Several other ARCAPA cases like ours, with severe stenosis of the left coronary artery, have been reported [4,16–17], while most adult patients of ARCAPA with angina pectoris, cardiac arrest or sudden death had no atherosclerotic disease of the normally originating left coronary artery [1,5–7]. In ARCAPA with severe atherosclerosis of the LCA, myocardial ischemia of the arterial perfusion territory of both coronaries may become serious because of the reduction of coronary arterial flow due to severe stenosis and the further increase of coronary steal via collaterals more proximal to the obstructive lesion compared with ARCAPA without coronary artery disease.
88
T. Nagai et al. / Legal Medicine 16 (2014) 84–88
Cx LAD CA Sep
RVA
RCA RVA
Fig. 9a. Schema of the coronary arterial flow of ARCAPA without atherosclerotic stenosis.
Cx LAD CA
RVA
RCA
Sep
RVA
Fig. 9b. Schema of the coronary arterial flow of ARCAPA with severe atherosclerotic stenosis (w).
In the present case, ARCAPA showing typical morphological findings of RCA anomaly with well-developed collateral circulation, was associated with a severe atherosclerotic lesion in the LCA. The anomalous RCA was dilated, thin-walled and vein-like in character without atherosclerotic lesions. On the other hand, the normally originated and distributed LCA was quite dilated and tortuous with severe atherosclerosis. Furthermore, the LAD showed more than 90% stenosis in the portion just distal of the first septal branch. Well-developed collateral circulations were observed between the left and right coronary arteries and several septal arteries were remarkably increased in caliber. Subendocardial vascular
dilatations mentioned by Cronk et al. [16] were seen. In the present case, these were sinusoid-like in the left ventricle and wall- thickened artery-like in the right ventricle, and connections between those vessels were seen in the ventricular septum, suggesting ‘intercoronary shunting’. Massive subendocardial fibroses in the perfusion territory of the LAD and the RCA, suggesting chronic myocardial ischemia, were seen. The lateral wall was spared from the chronic ischemia because the LCx was relatively patent and did not take off to the collateral circulation to the RCA. In addition to myocardial ischemia due to the coronary steal phenomenon via collateral circulations formed in the patient’s early life (Fig. 9a), severe stenosis of the relatively proximal region of the left anterior descending artery might have worsened the condition (myocardial ischemia) because of reduction of coronary artery flow and may have further increased the coronary steal (Fig. 9b). Furthermore, massive subendocardial fibroses may have become the foci of lethal arrhythmia by a reentrant mechanism [18]. Thus, the sudden death in our case may have been caused by deterioration of the myocardial ischemia due to rare coronary anomaly and severe atherosclerosis, and lethal arrhythmia based on the ischemic lesions of the myocardium. References [1] Lerberg DB, Ogden JA, Zuberbuhler JR, Bahnson HT. Anomalous origin of the right coronary artery from the pulmonary artery. Ann Thorac Surg 1979;27: 87–94. [2] Radke PW, Messmer BJ, Haager PK, Klues HG. Anomaluos origin of the right coronary artery: preoperative and postoperative hemodynamics. Ann Thorac Surg 1998;66:1444–9. [3] Williams IA, Gersony WM, Hellenbrand WE. Anomalous right coronary artery arising from the pulmonary artery: a report of 7 cases and a review of the literature. Am Heart J 2006;152:1004.e9–1004.e17. [4] Kuba PK, Sharma J, Sharma A. Successful surgical treatment of a septuagenarian with anomalous right coronary artery from the pulmonary artery with an eleven year follow-up. Sultan Qaboos Univ Med J 2013;13: 169–74. [5] Pribble RH. Anatomic variations of the coronary arteries and their clinical significance. J Indiana State Med Assoc 1961;54:329–33. [6] Wald S, Stonecipher K, Baldwin BJ, Nutter DO. Anomalous origin of the right coronary artery from the pulmonary artery. Am J Cardiol 1971;27:677–81. [7] Bregman D, Brennan FJ, Singer A, Vinci J, Parodi EN, Cassarella WJ, et al. Anomalous origin of the right coronary artery from the pulmonary artery. J Thorac Cardiovasc Surg 1976;72:626–30. [8] Brooks HSJ. Two cases of an abnormal coronary artery of the heart arising from the pulmonary artery: with some remarks upon the effect of this anomaly in producing cirsoid dilatation of the vessels. J Anat Physiol 1885;20:26–9. [9] Yamanaka O, Hobbs RE. Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Cathet Cardiovasc Diagn 1990;21:28–40. [10] Roberts WC. Major anomalies of coronary arterial origin seen in adulthood. Am Heart J 1986;111:941–63. [11] Edwards JE. The direction of blood flow in coronary arteries arising from the pulmonary trunk. Circulation 1964;29:163–6. [12] Wesselhoeft H, Fawcett JS, Johnson AL. Anomalous origin of the left coronary artery from the pulmonary trunk. Circulation 1968;38:403–25. [13] Mintz GS, Iskandrian AS, Bemis CE, Mundth ED, Owens JS. Myocardial ischemia in anomalous origin of the right coronary artery from the pulmonary trunk. Proof of a coronary steal. Am J Cardiol 1983;51:610–2. [14] Waite S, Ng T, Afari A, Gohari A, Lowery R. CT diagnosis of isolated anomalous origin of the RCA arising from the main pulmonary artery. J Thorac Imaging 2008;23:145–7. [15] Baskurt M, Yyldyz A, Caglar IM, Kylyckesmez K, Okcun B, Ozkan AA, et al. Right coronary artery arising from the pulmonary trunk. Thorac Cardiovasc Surg 2009;57:424–6. [16] Cronk ES, Sinclair JG, Rigdon RH. An anomalous coronary artery arising from the pulmonary artery. Am Heart J 1951;42:906–11. [17] Capuano C, Sesana M, Capuano F, Leonzi O, Cuccia C, Troise G. Right coronary artery arising from the pulmonary trunk. Cardiovasc Revasc Med 2007;8:76–9. [18] Mehta D, Curwin J, Gomes JA, Fuster V. Sudden death in coronary artery disease. Acute ischemia versus myocardial substrate. Circulation 1997;96: 3215–23.
