- Email: [email protected]
Acute myocardial infarction diagnosed early by multidetector computed tomography
114
Case Reports
infarction of the right ventricle and should lead to further attempts to exclude or confirm this diagnosis. These cases illustrate the diversity of clinical presentation in acute isolated right ventricular infarction. We emphasize the decisive role of echocardiography in reducing the time to diagnosis and expedite patient care. It should represent a standard investigation in patients with unexplained cardiovascular presentation. Mitja Lainscak MD, MSc General Hospital Murska Sobota Murska Sobota, Slovenia Andrej Pernat MD, PhD Department of Cardiology University Medical Centre Ljubljana SI-1000 Ljubljana, Slovenia E-mail address: [email protected] doi:10.1016/j.ajem.2006.05.022
References [1] Andersen HR, Falk E, Nielsen D. Right ventricular infarction: frequency, size, and topography in coronary heart disease. J Am Coll Cardiol 1987;10:1223 - 32. [2] Kinch JW, Ryan TJ. Right ventricular infarction. N Engl J Med 1994; 330:1211 - 7. [3] Zehender M, Kasper W, Kauder E, et al. Right ventricular infarction as an independent predictor of prognosis after acute inferior myocardial infarction. N Engl J Med 1993;328:981 - 8. [4] Antonelli D, Schiller D, Kaufman N, Barzilay J. Isolated right ventricular infarction: a diagnostic challenge. Cardiology 1984;71: 273 - 6. [5] Sanfilippo A, Weyman A. The role of echocardiography in managing critically ill patients. J Crit Illn 1988;3:27 - 44. [6] Oh JK, Seward JB, Khandheria BK, et al. Transesophageal echocardiography in critically ill patients. Am J Cardiol 1990;66:1492 - 5. [7] Heidenreich PA, Stainback RF, Redberg RF, et al. Transesophageal echocardiography predicts mortality in critically ill patients with unexplained hypotension. J Am Coll Cardiol 1995;26:152 - 8. [8] Durham B. Emergency medicine physicians saving time with ultrasound. Am J Emerg Med 1996;14:309 - 13. [9] Chockalingam A, Gnanavelu G, Subramaniam T, et al. Right ventricular myocardial infarction: presentation and acute outcomes. Angiology 2005;56:371 - 6. [10] Skali H, Zornoff LA, Pfeffer MA, et al. Prognostic use of echocardiography 1 year after a myocardial infarction. Am Heart J 2005;150: 743 - 9.
Acute myocardial infarction diagnosed early by multidetector computed tomography The development of multidector computed tomography (MDCT) has allowed assessment of not only coronary artery stenoses and occlusion, but also coronary artery plaques and myocardial perfusion [1]. Previous literature has emphasized its usefulness for detecting obstructive coronary artery
disease [2,3]. Recent publications also confirm that myocardial infarctions (MIs) can be seen on MDCT scan, but enrolled patients in these studies were in the subacute or chronic stage of MI [4- 6]. The clinical utility of MDCT to demonstrate acute MI has been reported in some cases with non–ST-elevation MI [1,7 -9]. Herein, we present a case of hyperacute stage of ST-elevation MI incidentally diagnosed early by this imaging modality before the electrocardiogram (ECG) or cardiac biomarkers became positive. A 52-year-old man presented to our emergency department (ED) with 20-minute symptoms of persistent anterior chest pain radiating to back associated with diaphoresis. He had a history of malignant melanoma of the right big toe postoperation. Physical examination was unremarkable. The initial ECG showed normal sinus rhythm with no evidence of ischemic changes, and cardiac enzyme analysis was within normal limits, with a creatine kinase (CK) of 34 U/L, CK-MB of 1 U/L, and troponin I of 0.04 ng/mL. Initial treatment included oxygen, aspirin, nitroglycerin, and morphine. A cardiologist was consulted because of unresolved symptoms, and bedside echocardiogram was interpreted as normal left ventricular function with an ejection fraction of 67%. A 40-slice, non–ECG-gated MDCT angiography (Philips, Cleveland, OH; 40 0.625-mm collimation, 500-millisecond rotation, 120 kV) was ordered to evaluate for potential aortic dissection, which demonstrated normal aorta but an area of transmural hypodensity with normal wall thickening along the anterior wall of the left ventricular and poor contrast-perfused left anterior descending coronary artery (LAD) suggesting an occlusion (Fig. 1). The repeated ECG 10 minutes after MDCT scan showed ST-segment elevation in leads V2 through V5. Primary coronary angiography was performed immediately and revealed a total occlusion of the middle LAD (Fig. 2). The patient underwent successful percutaneous transluminal coronary angioplasty with stent placement. Serial cardiac enzyme analysis confirmed a MI with an early peaking CK value of 2224 U/L (7% MB form) at 6 hours after onset of symptoms. The rest of the hospitalization course was uneventful. Evaluating patients who present with symptoms suggestive of acute coronary syndrome (ACS) remains a clinical challenge in the ED. Acute coronary syndrome constitutes a variety of clinical presentations, and other differential diagnosis such as abnormalities of the great vessels, pericardial disease, or gastrointestinal disorders may mimic it. Early diagnosis of ST-elevation MI is essential goal because it indicates the potential for a substantial irreversible infarction and is the primary indication for emergent reperfusion therapy to salvage the myocardium. The 12-lead ECG and cardiac enzyme levels are used to screen a suspected patient for ACS. It is known that a normal initial ECG does not preclude the diagnosis of acute MI [10], and cardiac enzymes may require 4 to 8 hours to have elapsed after the onset of coronary artery occlusion. The subsidiary noninvasive echocardiography is highly dependent on the operator and reader, and may be less
Case Reports
115
Fig. 1 A 40-slice non–ECG-gated contrast-enhanced MDCT delineated the myocardium, LAD, and left circumflex coronary artery. A, A transmural hypodense area along the anterior wall of the left ventricle (arrowhead). B, Poor contrast-perfused LAD (arrowhead). C, Poor contrast-perfused LAD (arrowhead) compared with the left circumflex coronary artery (arrow).
useful in patients who have preexisting wall motion abnormalities. Therefore, serial follow-up of ECG and cardiac enzymes every 2 to 4 hours is a validated practice in managing patients with ACS.
Considering the fast rotation time, multislice acquisition, and the high spatial resolution, MDCT is able to provide a comprehensive assessment about cardiac morphology and coronary angiography. In our case, an MDCT was ordered to
Fig. 2 The right anterior oblique view of conventional coronary angiography delineated the LAD in the pre- and postangioplasty stages. A, A total occlusion of the middle LAD (arrowhead). B, LAD in postangioplasty stage showing normal contrast perfusion (arrowhead).
116
Case Reports
exclude aortic dissection and incidentally demonstrated early the hyperacute stage of ST-elevation MI before the ECG or cardiac biomarkers became evidence. Patel et al [8] have reported incidentally discovered MI in 6 patients receiving MDCT scans for non–cardiac-related indications. Myocardial infarction can be visible on contrast-enhanced MDCT scan even when cardiac gating is not used [8]. The infarcted region is visualized as a segmental area of hypoattenuation in comparison with the normal enhanced myocardium during the arterial phase [4–6]. The normal wall thickness of the infarcted segment is consistently associated with a recent event and might be a useful criterion to differentiate recent (b1 month) from nonrecent (N1 month) MI [6]. In the report of Fancone et al [6], using MDCT in the detection of MI had a diagnostic accuracy, sensitivity, and specificity of 91%, 83%, and 91%, respectively. Sato et al [1] have indicated the feasibility of MDCT in the ED for detecting patients with ACS who did not manifest ECG and enzymatic evidence. In conclusion, further research should be aimed at determining the consistency and accuracy of MDCT for ACS. When the heart is included in a CT study, one should be alert to potential findings that indicate acute or chronic myocardial disease. Patients with symptoms suggestive of ACS, negative initial ECG, and missing cardiac enzymes may benefit from this efficient diagnostic modality.
Ju-Sing Fan MD Chorng-Kuang How MD Chii-Hwa Chern MD Lee-Min Wang MD Chun-I Huang MD Emergency Department Taipei Veterans General Hospital Taipei 112, Taiwan, ROC National Yang-Ming University School of Medicine Taipei 112, Taiwan, ROC E-mail address: [email protected]
[2] Nieman K, Rensing BJ, van Geuns RJM, et al. Usefulness of multislice computed tomography for detecting obstructive coronary artery disease. Am J Cardiol 2002;89:913 - 8. [3] Nieman K, Cademartiri F, Lemos PA, et al. Reliable non-invasive coronary angiography with fast submillimeter multislice spiral computed tomography. Circulation 2002;106:2051 - 4. [4] Gosalia A, Haramati LB, Sheth MP, et al. CT detection of acute myocardial infarction. AJR Am J Roentgenol 2004;182:1563 - 6. [5] Nikolaou K, Knez A, Sagmeister S, et al. Assessment of myocardial infarctions using multidetector-row computed tomography. J Comput Assist Tomogr 2004;28:286 - 92. [6] Francone M, Carbone I, Danti M, et al. ECG-gated multi-detector row spiral CT in the assessment of myocardial infarction: correlation with non-invasive angiographic findings. Eur Radiol 2006;16:15 - 24. [7] Paul JF, Dmabrin G, Caussin C, et al. Sixteen-slice computed tomography after acute myocardial infarction: from perfusion defect to the culprit lesion. Circulation 2003;108:373 - 4. [8] Patel R, Lewis D, Dubinsky TJ. Myocardial infarction non-ECG synchronized contrast-enhanced multi-detector computed tomography. Emerg Radiol 2005;11:301 - 5. [9] Zeina AR, Orlov I, Blinder J, et al. Atypical presentation of acute myocardial infarction in a young man diagnosed by multidetector computed tomography. Isr Med Assoc J 2006;8:69 - 70. [10] Menown IB, Mackenzie G, Adgey AA. Optimizing the initial 12-lead electrocardiographic diagnosis of acute myocardial infarction. Eur Heart J 2000;21:275 - 83.
Life-threatening epistaxis from a rare treatable cause Epistaxis after head injury is a common occurrence; however, epistaxis caused by a traumatic pseudoaneurysm of the internal carotid artery (ICA) is rare. This condition can be potentially fatal if unrecognized or diagnosed late, and its management differs from that of epistaxis of other causes.
Jen-Dar Chen MD Radiology Department Taipei Veterans General Hospital Taipei 112, Taiwan, ROC National Yang-Ming University School of Medicine Taipei 112, Taiwan, ROC doi:10.1016/j.ajem.2006.05.021
References [1] Sato Y, Matsumoto N, Ichikawa M, et al. Efficacy of multislice computed tomography for the detection of acute coronary syndrome in the emergency department. Circ J 2005;69:1047 - 51.
Fig. 1 Digital subtraction angiogram showing an aneurysm in the cavernous part of the ICA.
Case Reports
infarction of the right ventricle and should lead to further attempts to exclude or confirm this diagnosis. These cases illustrate the diversity of clinical presentation in acute isolated right ventricular infarction. We emphasize the decisive role of echocardiography in reducing the time to diagnosis and expedite patient care. It should represent a standard investigation in patients with unexplained cardiovascular presentation. Mitja Lainscak MD, MSc General Hospital Murska Sobota Murska Sobota, Slovenia Andrej Pernat MD, PhD Department of Cardiology University Medical Centre Ljubljana SI-1000 Ljubljana, Slovenia E-mail address: [email protected] doi:10.1016/j.ajem.2006.05.022
References [1] Andersen HR, Falk E, Nielsen D. Right ventricular infarction: frequency, size, and topography in coronary heart disease. J Am Coll Cardiol 1987;10:1223 - 32. [2] Kinch JW, Ryan TJ. Right ventricular infarction. N Engl J Med 1994; 330:1211 - 7. [3] Zehender M, Kasper W, Kauder E, et al. Right ventricular infarction as an independent predictor of prognosis after acute inferior myocardial infarction. N Engl J Med 1993;328:981 - 8. [4] Antonelli D, Schiller D, Kaufman N, Barzilay J. Isolated right ventricular infarction: a diagnostic challenge. Cardiology 1984;71: 273 - 6. [5] Sanfilippo A, Weyman A. The role of echocardiography in managing critically ill patients. J Crit Illn 1988;3:27 - 44. [6] Oh JK, Seward JB, Khandheria BK, et al. Transesophageal echocardiography in critically ill patients. Am J Cardiol 1990;66:1492 - 5. [7] Heidenreich PA, Stainback RF, Redberg RF, et al. Transesophageal echocardiography predicts mortality in critically ill patients with unexplained hypotension. J Am Coll Cardiol 1995;26:152 - 8. [8] Durham B. Emergency medicine physicians saving time with ultrasound. Am J Emerg Med 1996;14:309 - 13. [9] Chockalingam A, Gnanavelu G, Subramaniam T, et al. Right ventricular myocardial infarction: presentation and acute outcomes. Angiology 2005;56:371 - 6. [10] Skali H, Zornoff LA, Pfeffer MA, et al. Prognostic use of echocardiography 1 year after a myocardial infarction. Am Heart J 2005;150: 743 - 9.
Acute myocardial infarction diagnosed early by multidetector computed tomography The development of multidector computed tomography (MDCT) has allowed assessment of not only coronary artery stenoses and occlusion, but also coronary artery plaques and myocardial perfusion [1]. Previous literature has emphasized its usefulness for detecting obstructive coronary artery
disease [2,3]. Recent publications also confirm that myocardial infarctions (MIs) can be seen on MDCT scan, but enrolled patients in these studies were in the subacute or chronic stage of MI [4- 6]. The clinical utility of MDCT to demonstrate acute MI has been reported in some cases with non–ST-elevation MI [1,7 -9]. Herein, we present a case of hyperacute stage of ST-elevation MI incidentally diagnosed early by this imaging modality before the electrocardiogram (ECG) or cardiac biomarkers became positive. A 52-year-old man presented to our emergency department (ED) with 20-minute symptoms of persistent anterior chest pain radiating to back associated with diaphoresis. He had a history of malignant melanoma of the right big toe postoperation. Physical examination was unremarkable. The initial ECG showed normal sinus rhythm with no evidence of ischemic changes, and cardiac enzyme analysis was within normal limits, with a creatine kinase (CK) of 34 U/L, CK-MB of 1 U/L, and troponin I of 0.04 ng/mL. Initial treatment included oxygen, aspirin, nitroglycerin, and morphine. A cardiologist was consulted because of unresolved symptoms, and bedside echocardiogram was interpreted as normal left ventricular function with an ejection fraction of 67%. A 40-slice, non–ECG-gated MDCT angiography (Philips, Cleveland, OH; 40 0.625-mm collimation, 500-millisecond rotation, 120 kV) was ordered to evaluate for potential aortic dissection, which demonstrated normal aorta but an area of transmural hypodensity with normal wall thickening along the anterior wall of the left ventricular and poor contrast-perfused left anterior descending coronary artery (LAD) suggesting an occlusion (Fig. 1). The repeated ECG 10 minutes after MDCT scan showed ST-segment elevation in leads V2 through V5. Primary coronary angiography was performed immediately and revealed a total occlusion of the middle LAD (Fig. 2). The patient underwent successful percutaneous transluminal coronary angioplasty with stent placement. Serial cardiac enzyme analysis confirmed a MI with an early peaking CK value of 2224 U/L (7% MB form) at 6 hours after onset of symptoms. The rest of the hospitalization course was uneventful. Evaluating patients who present with symptoms suggestive of acute coronary syndrome (ACS) remains a clinical challenge in the ED. Acute coronary syndrome constitutes a variety of clinical presentations, and other differential diagnosis such as abnormalities of the great vessels, pericardial disease, or gastrointestinal disorders may mimic it. Early diagnosis of ST-elevation MI is essential goal because it indicates the potential for a substantial irreversible infarction and is the primary indication for emergent reperfusion therapy to salvage the myocardium. The 12-lead ECG and cardiac enzyme levels are used to screen a suspected patient for ACS. It is known that a normal initial ECG does not preclude the diagnosis of acute MI [10], and cardiac enzymes may require 4 to 8 hours to have elapsed after the onset of coronary artery occlusion. The subsidiary noninvasive echocardiography is highly dependent on the operator and reader, and may be less
Case Reports
115
Fig. 1 A 40-slice non–ECG-gated contrast-enhanced MDCT delineated the myocardium, LAD, and left circumflex coronary artery. A, A transmural hypodense area along the anterior wall of the left ventricle (arrowhead). B, Poor contrast-perfused LAD (arrowhead). C, Poor contrast-perfused LAD (arrowhead) compared with the left circumflex coronary artery (arrow).
useful in patients who have preexisting wall motion abnormalities. Therefore, serial follow-up of ECG and cardiac enzymes every 2 to 4 hours is a validated practice in managing patients with ACS.
Considering the fast rotation time, multislice acquisition, and the high spatial resolution, MDCT is able to provide a comprehensive assessment about cardiac morphology and coronary angiography. In our case, an MDCT was ordered to
Fig. 2 The right anterior oblique view of conventional coronary angiography delineated the LAD in the pre- and postangioplasty stages. A, A total occlusion of the middle LAD (arrowhead). B, LAD in postangioplasty stage showing normal contrast perfusion (arrowhead).
116
Case Reports
exclude aortic dissection and incidentally demonstrated early the hyperacute stage of ST-elevation MI before the ECG or cardiac biomarkers became evidence. Patel et al [8] have reported incidentally discovered MI in 6 patients receiving MDCT scans for non–cardiac-related indications. Myocardial infarction can be visible on contrast-enhanced MDCT scan even when cardiac gating is not used [8]. The infarcted region is visualized as a segmental area of hypoattenuation in comparison with the normal enhanced myocardium during the arterial phase [4–6]. The normal wall thickness of the infarcted segment is consistently associated with a recent event and might be a useful criterion to differentiate recent (b1 month) from nonrecent (N1 month) MI [6]. In the report of Fancone et al [6], using MDCT in the detection of MI had a diagnostic accuracy, sensitivity, and specificity of 91%, 83%, and 91%, respectively. Sato et al [1] have indicated the feasibility of MDCT in the ED for detecting patients with ACS who did not manifest ECG and enzymatic evidence. In conclusion, further research should be aimed at determining the consistency and accuracy of MDCT for ACS. When the heart is included in a CT study, one should be alert to potential findings that indicate acute or chronic myocardial disease. Patients with symptoms suggestive of ACS, negative initial ECG, and missing cardiac enzymes may benefit from this efficient diagnostic modality.
Ju-Sing Fan MD Chorng-Kuang How MD Chii-Hwa Chern MD Lee-Min Wang MD Chun-I Huang MD Emergency Department Taipei Veterans General Hospital Taipei 112, Taiwan, ROC National Yang-Ming University School of Medicine Taipei 112, Taiwan, ROC E-mail address: [email protected]
[2] Nieman K, Rensing BJ, van Geuns RJM, et al. Usefulness of multislice computed tomography for detecting obstructive coronary artery disease. Am J Cardiol 2002;89:913 - 8. [3] Nieman K, Cademartiri F, Lemos PA, et al. Reliable non-invasive coronary angiography with fast submillimeter multislice spiral computed tomography. Circulation 2002;106:2051 - 4. [4] Gosalia A, Haramati LB, Sheth MP, et al. CT detection of acute myocardial infarction. AJR Am J Roentgenol 2004;182:1563 - 6. [5] Nikolaou K, Knez A, Sagmeister S, et al. Assessment of myocardial infarctions using multidetector-row computed tomography. J Comput Assist Tomogr 2004;28:286 - 92. [6] Francone M, Carbone I, Danti M, et al. ECG-gated multi-detector row spiral CT in the assessment of myocardial infarction: correlation with non-invasive angiographic findings. Eur Radiol 2006;16:15 - 24. [7] Paul JF, Dmabrin G, Caussin C, et al. Sixteen-slice computed tomography after acute myocardial infarction: from perfusion defect to the culprit lesion. Circulation 2003;108:373 - 4. [8] Patel R, Lewis D, Dubinsky TJ. Myocardial infarction non-ECG synchronized contrast-enhanced multi-detector computed tomography. Emerg Radiol 2005;11:301 - 5. [9] Zeina AR, Orlov I, Blinder J, et al. Atypical presentation of acute myocardial infarction in a young man diagnosed by multidetector computed tomography. Isr Med Assoc J 2006;8:69 - 70. [10] Menown IB, Mackenzie G, Adgey AA. Optimizing the initial 12-lead electrocardiographic diagnosis of acute myocardial infarction. Eur Heart J 2000;21:275 - 83.
Life-threatening epistaxis from a rare treatable cause Epistaxis after head injury is a common occurrence; however, epistaxis caused by a traumatic pseudoaneurysm of the internal carotid artery (ICA) is rare. This condition can be potentially fatal if unrecognized or diagnosed late, and its management differs from that of epistaxis of other causes.
Jen-Dar Chen MD Radiology Department Taipei Veterans General Hospital Taipei 112, Taiwan, ROC National Yang-Ming University School of Medicine Taipei 112, Taiwan, ROC doi:10.1016/j.ajem.2006.05.021
References [1] Sato Y, Matsumoto N, Ichikawa M, et al. Efficacy of multislice computed tomography for the detection of acute coronary syndrome in the emergency department. Circ J 2005;69:1047 - 51.
Fig. 1 Digital subtraction angiogram showing an aneurysm in the cavernous part of the ICA.