CLINICAL COMMUNICATION TO THE EDITOR
Myocardial Infarction Related to a Coronary Artery Aneurysm
territory corresponding with the area of focal infarction. The rest of the examination results were essentially normal. Coronary calcium score was 0.
To the Editor: A 59-year-old woman presented with classic anginaltype chest pain lasting for a few hours before presentation to the hospital. However, she did not have any established risk factors for coronary artery disease. She never smoked, and there was no family history of coronary artery disease.
CLINICAL PRESENTATION The patient was hemodynamically stable on admission with a heart rate of 98 beats/min and blood pressure of 140/80 mm Hg. There was no jugular venous distension. All peripheral pulses were palpable, and no cardiac murmurs were auscultated. There were no diagnostic electrocardiographic changes. However, her troponin I level was increasing, peaking at 34.0 ng/mL. She received aspirin, clopidogrel, and statin on presentation. Transthoracic echocardiography showed no obvious wall motion abnormality, and ejection fraction was 55%. Because she had no cardiovascular risk factors, a low Thrombolysis in Myocardial Infarction score, no significant electrocardiogram changes, and high troponins, the clinical suspicion was acute myocarditis. Cardiac magnetic resonance was performed, which showed focal transmural delayed myocardial enhancement in the mid-inferolateral segment without any associated myocardial edema (Figure 1A). These findings were consistent with focal myocardial infarction in the inferolateral territory. In this patient with no established coronary artery disease risk factors, we opted for a noninvasive evaluation of the coronary arteries. Computed tomography angiography was performed, which showed a small aneurysmal dilatation in the mid portion of an obtuse marginal artery (Figure 1B). The location of the aneurysm correlated with the vascular
Funding: None. Conflict of Interest: None. Authorship: All authors had access to the data and played a role in writing this manuscript. Requests for reprints should be addressed to Rajesh Janardhanan, MD, MRCP, FACC, FASE, Division of Cardiology, Department of Internal Medicine, University of Arizona Medical Center, Sarver Heart Center, Box 245037, 1501 N. Campbell Ave, Tucson, AZ 85724. E-mail address: [email protected]
0002-9343/$ -see front matter Ó 2015 Elsevier Inc. All rights reserved.
DISCUSSION Coronary artery aneurysms are relatively uncommon. Male subjects are more commonly affected. The right coronary artery is most commonly involved, and left main coronary artery involvement is rare. Atherosclerosis is the most common cause of coronary artery aneurysm. Vasculitis without atherosclerosis causes coronary artery aneurysm in young children with Kawasaki disease. The risk factors for development of coronary artery aneurysm seem to be similar as those for coronary artery disease and abdominal aortic aneurysm. Apart from symptoms of angina or infarction, there are no specific signs or symptoms of coronary artery aneurysm. Most of the evidence regarding coronary artery aneurysm comes from case series and case reports. Thrombosis and distal embolization are the most probable causes of the acute coronary syndromeelike presentation in patients with coronary artery aneurysm without underlying coronary artery obstruction/atherosclerosis. Thrombosis occurs first in the aneurysm, which most of the time is asymptomatic. Patients develop symptoms when the thrombus either propagates and occludes the coronary artery, usually proximal to the aneurysm, or disrupts and lodges in a distal artery (embolic phenomenon). Befeler et al1 described a case series in which segmental left ventricular dysfunction was observed in the territory of coronary artery with aneurysm, but without obstruction.1 It was hypothesized that distal embolization of thrombus originating in the aneurysm was the cause. The actual incidence of thrombus formation in aneurysm and distal embolization still remains unclear.
CONCLUSIONS We present a case of acute myocardial infarction with an unusual and unexpected cause. Our patient presented with an acute coronary syndrome-like picture. Because she was relatively young with no established cardiovascular risk factors, obstructive coronary artery disease was low on our differential diagnosis. Of note, cardiac magnetic resonance demonstrated focal transmural inferolateral infarction with no other clinical or imaging findings to suggest myocarditis as a cause of the focal delayed myocardial enhancement.
e6
The American Journal of Medicine, Vol 128, No 2, February 2015
Figure 1 (A) Transmural delayed enhancement in the inferolateral segment on cardiac magnetic resonance imaging. (B) An aneurysm of the obtuse marginal artery on coronary computed tomography angiography.
c
Division of Cardiology Sarver Heart Center Department of Internal Medicine University of Arizona Medical Center Tucson
Subsequent computed tomography angiography showed a small aneurysm in the same distribution as the focal infarction. Thrombus development in the aneurysm with distal embolization seems to be the likely explanation. Ahmed Khurshid Pasha, MDa Clinton E. Jokerst, MDb Rajesh Janardhanan, MDc a Department of Internal Medicine University of Arizona Medical Center Tucson b Department of Medical Imaging University of Arizona Medical Center Tucson
http://dx.doi.org/10.1016/j.amjmed.2014.10.017
Reference 1. Befeler B, Aranda MJ, Embi A, Mullin FL, El-Sherif N, Lazzara R. Coronary artery aneurysms: study of the etiology, clinical course and effect on left ventricular function and prognosis. Am J Med. 1977;62: 597-607.
Myocardial Infarction Related to a Coronary Artery Aneurysm
territory corresponding with the area of focal infarction. The rest of the examination results were essentially normal. Coronary calcium score was 0.
To the Editor: A 59-year-old woman presented with classic anginaltype chest pain lasting for a few hours before presentation to the hospital. However, she did not have any established risk factors for coronary artery disease. She never smoked, and there was no family history of coronary artery disease.
CLINICAL PRESENTATION The patient was hemodynamically stable on admission with a heart rate of 98 beats/min and blood pressure of 140/80 mm Hg. There was no jugular venous distension. All peripheral pulses were palpable, and no cardiac murmurs were auscultated. There were no diagnostic electrocardiographic changes. However, her troponin I level was increasing, peaking at 34.0 ng/mL. She received aspirin, clopidogrel, and statin on presentation. Transthoracic echocardiography showed no obvious wall motion abnormality, and ejection fraction was 55%. Because she had no cardiovascular risk factors, a low Thrombolysis in Myocardial Infarction score, no significant electrocardiogram changes, and high troponins, the clinical suspicion was acute myocarditis. Cardiac magnetic resonance was performed, which showed focal transmural delayed myocardial enhancement in the mid-inferolateral segment without any associated myocardial edema (Figure 1A). These findings were consistent with focal myocardial infarction in the inferolateral territory. In this patient with no established coronary artery disease risk factors, we opted for a noninvasive evaluation of the coronary arteries. Computed tomography angiography was performed, which showed a small aneurysmal dilatation in the mid portion of an obtuse marginal artery (Figure 1B). The location of the aneurysm correlated with the vascular
Funding: None. Conflict of Interest: None. Authorship: All authors had access to the data and played a role in writing this manuscript. Requests for reprints should be addressed to Rajesh Janardhanan, MD, MRCP, FACC, FASE, Division of Cardiology, Department of Internal Medicine, University of Arizona Medical Center, Sarver Heart Center, Box 245037, 1501 N. Campbell Ave, Tucson, AZ 85724. E-mail address: [email protected]
0002-9343/$ -see front matter Ó 2015 Elsevier Inc. All rights reserved.
DISCUSSION Coronary artery aneurysms are relatively uncommon. Male subjects are more commonly affected. The right coronary artery is most commonly involved, and left main coronary artery involvement is rare. Atherosclerosis is the most common cause of coronary artery aneurysm. Vasculitis without atherosclerosis causes coronary artery aneurysm in young children with Kawasaki disease. The risk factors for development of coronary artery aneurysm seem to be similar as those for coronary artery disease and abdominal aortic aneurysm. Apart from symptoms of angina or infarction, there are no specific signs or symptoms of coronary artery aneurysm. Most of the evidence regarding coronary artery aneurysm comes from case series and case reports. Thrombosis and distal embolization are the most probable causes of the acute coronary syndromeelike presentation in patients with coronary artery aneurysm without underlying coronary artery obstruction/atherosclerosis. Thrombosis occurs first in the aneurysm, which most of the time is asymptomatic. Patients develop symptoms when the thrombus either propagates and occludes the coronary artery, usually proximal to the aneurysm, or disrupts and lodges in a distal artery (embolic phenomenon). Befeler et al1 described a case series in which segmental left ventricular dysfunction was observed in the territory of coronary artery with aneurysm, but without obstruction.1 It was hypothesized that distal embolization of thrombus originating in the aneurysm was the cause. The actual incidence of thrombus formation in aneurysm and distal embolization still remains unclear.
CONCLUSIONS We present a case of acute myocardial infarction with an unusual and unexpected cause. Our patient presented with an acute coronary syndrome-like picture. Because she was relatively young with no established cardiovascular risk factors, obstructive coronary artery disease was low on our differential diagnosis. Of note, cardiac magnetic resonance demonstrated focal transmural inferolateral infarction with no other clinical or imaging findings to suggest myocarditis as a cause of the focal delayed myocardial enhancement.
e6
The American Journal of Medicine, Vol 128, No 2, February 2015
Figure 1 (A) Transmural delayed enhancement in the inferolateral segment on cardiac magnetic resonance imaging. (B) An aneurysm of the obtuse marginal artery on coronary computed tomography angiography.
c
Division of Cardiology Sarver Heart Center Department of Internal Medicine University of Arizona Medical Center Tucson
Subsequent computed tomography angiography showed a small aneurysm in the same distribution as the focal infarction. Thrombus development in the aneurysm with distal embolization seems to be the likely explanation. Ahmed Khurshid Pasha, MDa Clinton E. Jokerst, MDb Rajesh Janardhanan, MDc a Department of Internal Medicine University of Arizona Medical Center Tucson b Department of Medical Imaging University of Arizona Medical Center Tucson
http://dx.doi.org/10.1016/j.amjmed.2014.10.017
Reference 1. Befeler B, Aranda MJ, Embi A, Mullin FL, El-Sherif N, Lazzara R. Coronary artery aneurysms: study of the etiology, clinical course and effect on left ventricular function and prognosis. Am J Med. 1977;62: 597-607.
