Although ST-segment elevation in precordial leads is a characteristic of anterior left ventricular infarction (LVI), it may also be observed in patients with proximal right coronary occlusion. An isolated right ventricular infarction (RVI) accounts for only 3 % of all myocardial infarctions (MI) [1]; in these cases, the ST-segment elevation in the precordial leads V1–V3 also may occur in the absence of inferior electrocardiographic changes [2], whereas the combination of RVI with inferior LVI suppresses ST-segment elevation in the precordial leads and yields an STsegment elevation in leads DII, DIII, and aVF [3]. Although certain electrocardiographic features have been suggested to help differentiate ST-segment elevation secondary to isolated RVI from LVI [3], it may be impossible to make a differential diagnosis on the basis of electrocardiography alone because these features are not pathognomonic. Furthermore, when a patient is admitted for typical chest pain, slight ST-segment elevation in leads V1–V3 and significant increase of cardiac troponin but with normal coronary main vessels at the coronary angiography, the diagnosis of a RVI is challenging; taking into account the multiple causes of myocardial injury and treatment consequences, there is great clinical need to clarify the underlying reason for cardiac troponin release. Although some studies report that echocardiography is a valuable clinical tool for the evaluation of global RV function [4], geometric assumptions in modeling the complex RV shape restricts the ability of this technique in accurate and precise quantification of RV function; furthermore, RV function assessment can be difficult in patients with poor acoustic window or when minor alterations of RV function are present. Cardiac magnetic resonance (CMR) provides a comprehensive, multifaceted view of the heart and can be useful to characterize an infarct site and size accurately [5]. CMR in this particular setting can confirm the presence of a minor RVI and aid to exclude other potential causes of troponin rise with normal coronary main vessels at the coronary angiography, such as embolic myocardial infarction or myocarditis [6]. Acute MI treatment [7–10] and traditional predictors of long-term mortality after acute MI are well characterized [11–14] but with introduction of CMR, new predictors of cardiovascular events are emerging [15, 16] and the evaluation of RV function using CMR can improve risk stratification and potentially refine patient management after MI [17]. Moreover, the extent of myocardial scar characterized by CMR is significantly associated with the occurrence of spontaneous ventricular arrhythmias [18]. There have been few reports of anterior ST-segment elevation caused by isolated RVI due to right ventricle branch occlusion [19–21]. Occlusion of the conus branch has been described essentially as a complication of coronary angioplasty or during cardiac surgery [19–21]. Only one report described a spontaneous RVI with culprit lesion in the conus branch [22]. Assessment of isolated RVI due to a critical stenosis of the conus branch by magnetic resonance is never been reported.

Uncommon cause of ST-segment elevation in V1-V3: incremental value of cardiac magnetic resonance imaging

FABRIS, ENRICO;SINAGRA, GIANFRANCO;
2014

Abstract

Although ST-segment elevation in precordial leads is a characteristic of anterior left ventricular infarction (LVI), it may also be observed in patients with proximal right coronary occlusion. An isolated right ventricular infarction (RVI) accounts for only 3 % of all myocardial infarctions (MI) [1]; in these cases, the ST-segment elevation in the precordial leads V1–V3 also may occur in the absence of inferior electrocardiographic changes [2], whereas the combination of RVI with inferior LVI suppresses ST-segment elevation in the precordial leads and yields an STsegment elevation in leads DII, DIII, and aVF [3]. Although certain electrocardiographic features have been suggested to help differentiate ST-segment elevation secondary to isolated RVI from LVI [3], it may be impossible to make a differential diagnosis on the basis of electrocardiography alone because these features are not pathognomonic. Furthermore, when a patient is admitted for typical chest pain, slight ST-segment elevation in leads V1–V3 and significant increase of cardiac troponin but with normal coronary main vessels at the coronary angiography, the diagnosis of a RVI is challenging; taking into account the multiple causes of myocardial injury and treatment consequences, there is great clinical need to clarify the underlying reason for cardiac troponin release. Although some studies report that echocardiography is a valuable clinical tool for the evaluation of global RV function [4], geometric assumptions in modeling the complex RV shape restricts the ability of this technique in accurate and precise quantification of RV function; furthermore, RV function assessment can be difficult in patients with poor acoustic window or when minor alterations of RV function are present. Cardiac magnetic resonance (CMR) provides a comprehensive, multifaceted view of the heart and can be useful to characterize an infarct site and size accurately [5]. CMR in this particular setting can confirm the presence of a minor RVI and aid to exclude other potential causes of troponin rise with normal coronary main vessels at the coronary angiography, such as embolic myocardial infarction or myocarditis [6]. Acute MI treatment [7–10] and traditional predictors of long-term mortality after acute MI are well characterized [11–14] but with introduction of CMR, new predictors of cardiovascular events are emerging [15, 16] and the evaluation of RV function using CMR can improve risk stratification and potentially refine patient management after MI [17]. Moreover, the extent of myocardial scar characterized by CMR is significantly associated with the occurrence of spontaneous ventricular arrhythmias [18]. There have been few reports of anterior ST-segment elevation caused by isolated RVI due to right ventricle branch occlusion [19–21]. Occlusion of the conus branch has been described essentially as a complication of coronary angioplasty or during cardiac surgery [19–21]. Only one report described a spontaneous RVI with culprit lesion in the conus branch [22]. Assessment of isolated RVI due to a critical stenosis of the conus branch by magnetic resonance is never been reported.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11368/2838989
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