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Diagnosis of an uncommon case of myocarditis by cardiac magnetic resonance imaging: Ventricular tachycardia caused by inflammatory left ventricular microaneurysms
International Journal of Cardiology 134 (2009) e11 – e14 www.elsevier.com/locate/ijcard
Letter to the Editor
Diagnosis of an uncommon case of myocarditis by cardiac magnetic resonance imaging: Ventricular tachycardia caused by inflammatory left ventricular microaneurysms N. Girerd a,⁎, C. Besnard a , V. Thomson b , A. Gressard a , P. Lantelme a,c a b
Cardiology Department, Hopital de la Croix Rousse, Hospices civils de Lyon, 103, Grande Rue de la Croix-Rousse, 69 317 Lyon cedex 04, France Radiology Department, Hopital de la Croix Rousse, Hospices civils de Lyon, 103, Grande Rue de la Croix-Rousse, 69 317 Lyon cedex 04, France c Université Lyon-1, INSERM ERI 22, Lyon — F69008, France Received 4 October 2007; accepted 15 December 2007 Available online 18 March 2008
Abstract Cardiac magnetic resonance imaging (CMRI) has recently proved to be a powerful tool in the diagnosis of myocarditis. We report a case of myocarditis diagnosed with CMRI in a rare setting: An episode of ventricular tachycardia (VT) arising from the left ventricle associated with a unique ventricular microaneurysm in a patient free of coronary disease. Because of this benign feature, the patient was discharged with antiarrhythmics with no further investigation. A 9-month follow-up revealed no VT recurrence. This case demonstrates the importance of CMRI in patients suffering from apparently idiopathic VT originating in the left ventricle. © 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Cardiac magnetic resonance; Ventricular tachycardia; Inflammatory left ventricular microaneurysm; Myocarditis
1. Introduction Myocarditis can hardly be diagnosed by conventional techniques. Even endomyocardial biopsy is often unable to provide the diagnosis [1,2]. Therefore, further non-invasive cardiac methods are often needed. Cardiac magnetic resonance imaging (CMRI) has recently proved to be a powerful tool for the diagnosis of myocarditis [1–4]. 2. Case report A previously healthy 50-year-old man was admitted to the hospital after an episode of ventricular tachycardia (VT). While he had been jogging for 45 min, the patient felt acute dizziness associated with presyncope symptoms. At arrival of the emergency medical team, the patient was confused.
⁎ Corresponding author. E-mail address: [email protected] (N. Girerd). 0167-5273/$ - see front matter © 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2007.12.052
Systolic blood pressure was measured at 60 mmHg. The EKG revealed a VT at 250 bpm with right bundle-branch block (RBBB) contour and left-axis deviation. An IV injection of amiodarone did not succeed in restoring sinusal rhythm. Eventually, external cardioversion ended the episode of VT. Subsequent troponin I rose and peaked at 3.42 ng/mL. Baseline EKG was unremarkable. Transthoracic Doppler echocardiography showed a slight increase of left ventricular (LV) wall thickness (13.6 mm) but no wall motion abnormalities. Two out of three late potentials, investigated with signal-averaged EKG, were positive. Holter-monitoring revealed few ventricular ectopic beats with some couples. The coronary angiography showed no significant stenosis. LV angiography confirmed normal contractility but revealed, remarkably, a small aneurysm in the inferior wall, persisting during systole and diastole (Fig. 1). On day 12, a CMRI was performed to rule out an ischemic phenomenon, and assess LV hypertrophy. It showed neither wall motion abnormalities nor elevated LV mass (62 g/m2). Surprisingly, cine imaging, performed before the
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Fig. 1. LV angiography showing a small aneurysm in the inferior wall.
gadolinium injection, showed hyperintense signal in the inferolateral wall during systole only (Fig. 2). Delayedenhancement imaging showed extensive subepicardial enhancement in the lateral and inferolateral wall, associated with a patchy intramyocardial and subepicardial enhancement in the septal region and anterior wall (Fig. 2). Those findings were highly consistent with acute myocarditis. Retrospectively, the patient remembered having a flu-like episode, with cough, mild fever and generalized fatigue, a few weeks before the tachyarrhythmic event. Antibody titers for CMV, EBV, HVC, HIV, Coxsackie and Adenovirus were normal. The patient was discharged home with an antiarrhythmic treatment consisting in 25 mg of atenolol. No other drugs were maintained. At 2-month follow-up, exercise stress testing, performed without beta-blocker disruption, did not induce any arrhythmic event. A control CMRI showed subepicardial enhancements in the exact same location as earlier, thus consistent with fibrosis. Late potentials also remained pathological. Beta-blocker treatment was continued. A 9-month follow-up revealed no VT recurrence. 3. Discussion VT in patients having structurally normal heart is a distinct entity [5]. Inflammatory LV microaneurysms are a cause of VT in such patients, representing 9.6% of cases in a large series reported by Chimenti et al. [6]. Unique inflam-
matory microaneurysms are detected only during angiography [6]. All reported patients suffered from recurrent episodes of VT with RBBB morphology, and were diagnosed with lymphocitic myocarditis by histopathology [6]. In the patients undergoing ventricular mapping, VT originated close to the aneurysms [6]. Localized myocytolysis due to intense inflammation resulting in transmural destruction could be incriminated in the pathogenesis of microaneurysms [6]. VT in this context is of benign prognosis and can be treated by antiarrhythmics [6]. Treatment of idiopathic VT consists in catheter ablation (CA) in patients with symptomatic, drug-refractory VT [5]. Electrophysiological testing establishes precise diagnosis when curative CA is needed [5]. ICD implantation is recommended in patients suffering from sustained VT receiving chronic optimal medical therapy [5]. On the contrary, ICD implantation is never indicated during the acute phase of myocarditis, and CA does not seem of interest in this context [5]. In our patient, the very poor tolerance of the episode of VT (both neurological and hemodynamic), and its resistance to amiodarone made us fear a lifethreatening recurrence, and eventually, sudden death. If the diagnosis of myocaditis had not been established by CMRI, we would have considered ICD therapy. Both ICD implantation and electrophysiological testing were considered inappropriate regarding the diagnosis of myocarditis. Furthermore, considering the particularly benign prognosis of VT due to myocarditis with inflammatory LV microaneurysm, antiarrhythmics were considered an appropriate treatment. Identifying patients with acute myocarditis is challenging. Traditionally used diagnostic tests are often unable to assess the diagnosis [1]. Endomyocardial biopsy, still considered to be the gold standard, suffers from a very poor sensitivity (10 to 22%) [1,2]. CMRI has recently emerged as an important tool in the diagnosis and assessment of myocarditis [1–4]. T2-weighted and contrast-enhanced CMRI are of particular interest [1,3]. Many CMRI findings are consistent with myocarditis: multiple high-signal spots, global T2 signal intensity, areas of late gadolinium enhancement [1]…. These CMRI findings achieve a very good sensitivity and specificity, sometimes close to 100% for both parameters [1]. Interestingly, we found a hyperintense signal in the inferolateral wall in systolic cine images, concurring with the inferolateral wall late-enhancement. It could be another CMRI finding consistent with edema in the context of myocarditis. Moreover, CMRI is particularly useful to differentiate acute myocarditis from myocardial infarction in unclear situations [1,2,4]. Indeed, delayed-enhancement is subepicardial in myocarditis, whereas it is subendocardial or transmural in myocardial infarction [1,4].
Fig. 2. CMRI: Delayed-enhancement imaging (A to D) and cine imaging (E to F). Cine imaging was performed before gadolinium injection. Vertical long axis (A), four-chamber (B), and short axis (C and D), showing extensive subepicardial enhancement in the lateral and inferolateral wall, associated with a patchy intramyocardial and subepicardial enhancement in the septal region and anterior wall. Systolic cine image (F) showing hyperintense signal in the inferolateral wall. This hyperintense signal was not found on diastolic images (E) but this exact same region showed delayed-enhancement on images C and D.
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4. Conclusion CMRI is a powerful tool in the diagnosis of myocarditis. In the setting of VT with LV microaneurysms, the diagnosis of myocarditis is of crucial importance considering the therapeutic implications involved. In our opinion, CMRI should be systematically proposed in patients suspected of Idiopathic VT arising from the LV and free of coronary disease, particularly in presence of LV microaneurysms. References [1] Skouri HN, Dec GW, Friedrich MG, Cooper LT. Noninvasive imaging in myocarditis. J Am Coll Cardiol 2006;48(10):2085–93. [2] Hakeem A, Bhatti S, Fuh A, et al. Viral myocarditis masquerading acute coronary syndrome (ACS)—MRI to the rescue. Int J Cardiol 2007;119(3): e74–6.
[3] Di Bella G, de Gregorio C, Minutoli F, et al. Early diagnosis of focal myocarditis by cardiac magnetic resonance. Int J Cardiol 2007;117(2): 280–1. [4] Garcia-Pavia P, Aguiar-Souto P, Silva-Melchor L, et al. Cardiac magnetic resonance imaging in the diagnosis of myocarditis mimicking myocardial infarction. Int J Cardiol 2006;112(2):e27–e279. [5] Zipes DP, Camm AJ, Borggrefe M, et al. ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: a report of the ACC/AHA Task Force and the ESC Committee for Practice Guidelines (writing committee to develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Circulation 2006;114(10):e385–484. [6] Chimenti C, Calabrese F, Thiene G, Pieroni M, Maseri A, Frustaci A. Inflammatory left ventricular microaneurysms as a cause of apparently idiopathic ventricular tachyarrhythmias. Circulation 2001;104(2): 168–73.
Letter to the Editor
Diagnosis of an uncommon case of myocarditis by cardiac magnetic resonance imaging: Ventricular tachycardia caused by inflammatory left ventricular microaneurysms N. Girerd a,⁎, C. Besnard a , V. Thomson b , A. Gressard a , P. Lantelme a,c a b
Cardiology Department, Hopital de la Croix Rousse, Hospices civils de Lyon, 103, Grande Rue de la Croix-Rousse, 69 317 Lyon cedex 04, France Radiology Department, Hopital de la Croix Rousse, Hospices civils de Lyon, 103, Grande Rue de la Croix-Rousse, 69 317 Lyon cedex 04, France c Université Lyon-1, INSERM ERI 22, Lyon — F69008, France Received 4 October 2007; accepted 15 December 2007 Available online 18 March 2008
Abstract Cardiac magnetic resonance imaging (CMRI) has recently proved to be a powerful tool in the diagnosis of myocarditis. We report a case of myocarditis diagnosed with CMRI in a rare setting: An episode of ventricular tachycardia (VT) arising from the left ventricle associated with a unique ventricular microaneurysm in a patient free of coronary disease. Because of this benign feature, the patient was discharged with antiarrhythmics with no further investigation. A 9-month follow-up revealed no VT recurrence. This case demonstrates the importance of CMRI in patients suffering from apparently idiopathic VT originating in the left ventricle. © 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Cardiac magnetic resonance; Ventricular tachycardia; Inflammatory left ventricular microaneurysm; Myocarditis
1. Introduction Myocarditis can hardly be diagnosed by conventional techniques. Even endomyocardial biopsy is often unable to provide the diagnosis [1,2]. Therefore, further non-invasive cardiac methods are often needed. Cardiac magnetic resonance imaging (CMRI) has recently proved to be a powerful tool for the diagnosis of myocarditis [1–4]. 2. Case report A previously healthy 50-year-old man was admitted to the hospital after an episode of ventricular tachycardia (VT). While he had been jogging for 45 min, the patient felt acute dizziness associated with presyncope symptoms. At arrival of the emergency medical team, the patient was confused.
⁎ Corresponding author. E-mail address: [email protected] (N. Girerd). 0167-5273/$ - see front matter © 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2007.12.052
Systolic blood pressure was measured at 60 mmHg. The EKG revealed a VT at 250 bpm with right bundle-branch block (RBBB) contour and left-axis deviation. An IV injection of amiodarone did not succeed in restoring sinusal rhythm. Eventually, external cardioversion ended the episode of VT. Subsequent troponin I rose and peaked at 3.42 ng/mL. Baseline EKG was unremarkable. Transthoracic Doppler echocardiography showed a slight increase of left ventricular (LV) wall thickness (13.6 mm) but no wall motion abnormalities. Two out of three late potentials, investigated with signal-averaged EKG, were positive. Holter-monitoring revealed few ventricular ectopic beats with some couples. The coronary angiography showed no significant stenosis. LV angiography confirmed normal contractility but revealed, remarkably, a small aneurysm in the inferior wall, persisting during systole and diastole (Fig. 1). On day 12, a CMRI was performed to rule out an ischemic phenomenon, and assess LV hypertrophy. It showed neither wall motion abnormalities nor elevated LV mass (62 g/m2). Surprisingly, cine imaging, performed before the
e12
N. Girerd et al. / International Journal of Cardiology 134 (2009) e11–e14
Fig. 1. LV angiography showing a small aneurysm in the inferior wall.
gadolinium injection, showed hyperintense signal in the inferolateral wall during systole only (Fig. 2). Delayedenhancement imaging showed extensive subepicardial enhancement in the lateral and inferolateral wall, associated with a patchy intramyocardial and subepicardial enhancement in the septal region and anterior wall (Fig. 2). Those findings were highly consistent with acute myocarditis. Retrospectively, the patient remembered having a flu-like episode, with cough, mild fever and generalized fatigue, a few weeks before the tachyarrhythmic event. Antibody titers for CMV, EBV, HVC, HIV, Coxsackie and Adenovirus were normal. The patient was discharged home with an antiarrhythmic treatment consisting in 25 mg of atenolol. No other drugs were maintained. At 2-month follow-up, exercise stress testing, performed without beta-blocker disruption, did not induce any arrhythmic event. A control CMRI showed subepicardial enhancements in the exact same location as earlier, thus consistent with fibrosis. Late potentials also remained pathological. Beta-blocker treatment was continued. A 9-month follow-up revealed no VT recurrence. 3. Discussion VT in patients having structurally normal heart is a distinct entity [5]. Inflammatory LV microaneurysms are a cause of VT in such patients, representing 9.6% of cases in a large series reported by Chimenti et al. [6]. Unique inflam-
matory microaneurysms are detected only during angiography [6]. All reported patients suffered from recurrent episodes of VT with RBBB morphology, and were diagnosed with lymphocitic myocarditis by histopathology [6]. In the patients undergoing ventricular mapping, VT originated close to the aneurysms [6]. Localized myocytolysis due to intense inflammation resulting in transmural destruction could be incriminated in the pathogenesis of microaneurysms [6]. VT in this context is of benign prognosis and can be treated by antiarrhythmics [6]. Treatment of idiopathic VT consists in catheter ablation (CA) in patients with symptomatic, drug-refractory VT [5]. Electrophysiological testing establishes precise diagnosis when curative CA is needed [5]. ICD implantation is recommended in patients suffering from sustained VT receiving chronic optimal medical therapy [5]. On the contrary, ICD implantation is never indicated during the acute phase of myocarditis, and CA does not seem of interest in this context [5]. In our patient, the very poor tolerance of the episode of VT (both neurological and hemodynamic), and its resistance to amiodarone made us fear a lifethreatening recurrence, and eventually, sudden death. If the diagnosis of myocaditis had not been established by CMRI, we would have considered ICD therapy. Both ICD implantation and electrophysiological testing were considered inappropriate regarding the diagnosis of myocarditis. Furthermore, considering the particularly benign prognosis of VT due to myocarditis with inflammatory LV microaneurysm, antiarrhythmics were considered an appropriate treatment. Identifying patients with acute myocarditis is challenging. Traditionally used diagnostic tests are often unable to assess the diagnosis [1]. Endomyocardial biopsy, still considered to be the gold standard, suffers from a very poor sensitivity (10 to 22%) [1,2]. CMRI has recently emerged as an important tool in the diagnosis and assessment of myocarditis [1–4]. T2-weighted and contrast-enhanced CMRI are of particular interest [1,3]. Many CMRI findings are consistent with myocarditis: multiple high-signal spots, global T2 signal intensity, areas of late gadolinium enhancement [1]…. These CMRI findings achieve a very good sensitivity and specificity, sometimes close to 100% for both parameters [1]. Interestingly, we found a hyperintense signal in the inferolateral wall in systolic cine images, concurring with the inferolateral wall late-enhancement. It could be another CMRI finding consistent with edema in the context of myocarditis. Moreover, CMRI is particularly useful to differentiate acute myocarditis from myocardial infarction in unclear situations [1,2,4]. Indeed, delayed-enhancement is subepicardial in myocarditis, whereas it is subendocardial or transmural in myocardial infarction [1,4].
Fig. 2. CMRI: Delayed-enhancement imaging (A to D) and cine imaging (E to F). Cine imaging was performed before gadolinium injection. Vertical long axis (A), four-chamber (B), and short axis (C and D), showing extensive subepicardial enhancement in the lateral and inferolateral wall, associated with a patchy intramyocardial and subepicardial enhancement in the septal region and anterior wall. Systolic cine image (F) showing hyperintense signal in the inferolateral wall. This hyperintense signal was not found on diastolic images (E) but this exact same region showed delayed-enhancement on images C and D.
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4. Conclusion CMRI is a powerful tool in the diagnosis of myocarditis. In the setting of VT with LV microaneurysms, the diagnosis of myocarditis is of crucial importance considering the therapeutic implications involved. In our opinion, CMRI should be systematically proposed in patients suspected of Idiopathic VT arising from the LV and free of coronary disease, particularly in presence of LV microaneurysms. References [1] Skouri HN, Dec GW, Friedrich MG, Cooper LT. Noninvasive imaging in myocarditis. J Am Coll Cardiol 2006;48(10):2085–93. [2] Hakeem A, Bhatti S, Fuh A, et al. Viral myocarditis masquerading acute coronary syndrome (ACS)—MRI to the rescue. Int J Cardiol 2007;119(3): e74–6.
[3] Di Bella G, de Gregorio C, Minutoli F, et al. Early diagnosis of focal myocarditis by cardiac magnetic resonance. Int J Cardiol 2007;117(2): 280–1. [4] Garcia-Pavia P, Aguiar-Souto P, Silva-Melchor L, et al. Cardiac magnetic resonance imaging in the diagnosis of myocarditis mimicking myocardial infarction. Int J Cardiol 2006;112(2):e27–e279. [5] Zipes DP, Camm AJ, Borggrefe M, et al. ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: a report of the ACC/AHA Task Force and the ESC Committee for Practice Guidelines (writing committee to develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Circulation 2006;114(10):e385–484. [6] Chimenti C, Calabrese F, Thiene G, Pieroni M, Maseri A, Frustaci A. Inflammatory left ventricular microaneurysms as a cause of apparently idiopathic ventricular tachyarrhythmias. Circulation 2001;104(2): 168–73.