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Electrocardiographic manifestions of proximal left anterior descending artery occlusion
Journal of Electrocardiology Vol. 36 No. 2 2003
Electrocardiographic Manifestions of Proximal Left Anterior Descending Artery Occlusion
Bernard M. Karnath, MD, John C. Champion, MD, and Masood Ahmad, MD
Abstract: We report the case of a 51-year-old woman who presents with a 2-week history of episodes of pressure like chest pain. The initial electrocardiogram was not indicative of myocardial ischemia or infarction and the cardiac enzymes remained normal during the initial hospital day. However, the precordial T waves inverted and progressively deepened on the second hospital day and the patient underwent cardiac catheterization with percutaneous coronary angioplasty and stent placement of the left anterior descending coronary artery with good results. The postprocedure electrocardiogram showed complete resolution of the inverted precordial T waves. The development of new T-wave inversions in the precordial leads of patients presenting with unstable angina is predictive of significant stenosis of the left anterior descending coronary artery. This subgroup of patients has a poor prognosis if medical therapy alone is instituted. Early cardiac catheterization and revascularization is recommended for these patients. Evidence has shown that 75% patients with these electrocardiogram changes who are not revascularized developed extensive anterior wall infarction within a few weeks. Key words: Anterior ischemia, Wellen’s Syndrome, T-wave inversions.
The patient is a 51-year-old woman who presents with a 2-week history of episodes of pressure like chest pain. An electrocardiogram (ECG) was obtained in the emergency department and reveals poor R-wave progression and an indeterminate axis (Fig. 1). The patient was admitted for observation with serial cardiac enzymes and ECGs. The cardiac enzymes remained normal. However, T-wave in-
versions became quite evident in the precordial leads on the second hospital day (Fig. 2). An echocardiogram revealed a left ventricular (LV) ejection fraction was 50%. The patient subsequently underwent cardiac catheterization.
Discussion From the Department of Internal Medicine, The University of Texas Medical Branch at Galveston, TX. Reprint requests: Bernard M. Karnath, MD, Department of Internal Medicine, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555-0566. © 2003 Elsevier Inc. All rights reserved. 0022-0736/03/3602-0014$30.00/0 doi:10.1054/jelc.2003.50024
Chest pain is a common presenting complaint in emergency departments. Work up of acute chest pain often includes serial cardiac enzymes and an ECG to rule out ischemic heart disease as an etiology. The ECG is the most commonly used diagnos173
174 Journal of Electrocardiology Vol. 36 No. 2 April 2003
Fig. 1. ECG on admission.
tic tool for patients presenting with symptoms of acute myocardial ischemia. The Presenting ECG The presenting ECG is remarkable for poor Rwave progression, Q waves in V1 and V2, and an
indeterminate axis. The findings in the anterior leads are somewhat suggestive of underlying LAD disease, albeit limited. One study found that the presence of Q waves in leads V1 and V2 indicated a limited apical myocardial infarction with relatively preserved LV function (1). The finding of an indeterminate axis in our patient, defined as equal
Fig. 2. ECG on the second hospital day.
Electrocardiographic Manifestations •
Karnath et al. 175
infarction. One study found that 20% of patients with poor R wave progression had fixed perfusion defects on Thallium-201 myocardial scintigraphy (3). Poor R-wave progression is defined as an Rwave amplitude of 0.3 mv or less in lead V3 combined with a smaller R wave in lead V2 (4). One study showed that the degree of loss of R wave in leads V5 and V6 correlated with a lower LV ejection fraction (1). Our patient had relatively preserved LV function with some mild posterior wall hypokinesis on baseline echocardiogram. Poor R-wave progression is not specific to anterior myocardial infarction, other causes such as emphysema, which can cause a downward displacement of the heart, can cause poor R-wave progression (5).
Development of T-wave Inversions Fig. 3. A wrapped LAD. Arrow indicates apex.
positive and negative components in all 6 frontal plane leads, is nonspecific as there may be many underlying causes (2). Poor R-wave progression is thought to be produced by loss of anterior forces of depolarization due to anteroseptal myocardial scar as a result of
Fig. 4. Pre- and post-PTCA angiograms.
The history of this patient is consistent with myocardial ischemia. The inversions of the precordial T waves are relatively deep and fairly symmetrical, typical of myocardial ischemia. T-wave inversions may be caused by a number of clinical syndromes including acute coronary ischemia, pulmonary embolism, and central nervous system injury (6). The extension of the T-wave inversions to the inferior leads is highly suggestive of a wrapped LAD. A wrapped LAD is defined as an LAD artery
176 Journal of Electrocardiology Vol. 36 No. 2 April 2003
Fig. 5. ECG after PTCA of the LAD lesion.
that perfuses at least one fourth of the inferior wall (7). The cardiac catheterization film shows a partially wrapped LAD (Fig. 3). In the original article by de Zwann et al. (8) in 1982, Dr Wellens warned of impending myocardial infarction in this subset of patients who developed deep T-wave inversions in the precordial leads after the resolution of chest pain. In fact, in their study 75% (12 of 16) of the patients with these ECG changes who were not revascularized developed extensive anterior wall infarction within a few weeks. Wellens’ syndrome, which is characterized by deeply inverted T waves in the precordial leads, is highly suggestive of proximal left anterior descending artery (LAD) stenosis (9). However, not all criteria for Wellen’s syndrome are met in our case. The criteria for Wellen’s syndrome include a history of anginal chest pain combined with T-wave inversions in the anterior chest leads, lack of Q waves and ST-segment elevations, lack of serum marker abnormalities, and normal R-wave progression (10). In our case, the initial ECG shows poor R-wave progression and and Q waves in leads V1 and V2. However, the patient was found to have proximal LAD stenosis with somewhat preserved LV function. The development of new T-wave inversions in the precordial leads of patients presenting with unstable angina is predictive of significant stenosis of the left anterior descending coronary artery with
a reported positive predictive value of 86% (11) this subgroup of patients has a poor prognosis if medical therapy alone is instituted (7). Early cardiac catheterization and revascularization is recommended for these patients (8). For patients with acute ischemic events without infarction, the persistence of inverted T waves is a strong predictor of further ischemic events (12). However, during in acute anterior myocardial infarction, the rapid appearance of giant negative T waves predicts R wave recovery (13). On the other hand, patients who experience resolution of Twave inversions after and ischemic event are less likely to experience further ischemic events (12). Revascularization Ischemic coronary events can result in stunned myocardium in which contractility falls. If the LAD is involved, LV function is likely to be impaired. Revascularization could improve LV function provided that the myocardium is stunned rather than infracted (14). Our patient underwent cardiac catheterization and percutaneous coronary angioplasty (PTCA) with stent placement in the LAD coronary artery on the third hospital day with good results (Fig. 4) The post-procedure ECG shows complete resolution of the inverted precordial T waves (Fig. 5) A follow-up echocardiogram performed 2 months later revealed and ejection fraction of 60%.
Electrocardiographic Manifestations •
Conclusion In a patient presenting with angina, the development of deep T-wave inversions in the setting of poor R-wave progression is highly suggestive of proximal LAD occlusion. The presence of small Q waves in the precordial leads V1 and V2 and presence of R wave forces in leads V5 and V6 is suggestive of limited myocardial infarction with relatively preserved LV function.
7.
8.
9.
References 1. Bogaty P, Boyer L, Rousseau L, et al: Is anteroseptal myocardial infarction an appropriate term? Am J Med 113:37, 2002 2. Goldberger AL: The genesis of indeterminate axis: A quantitative vectorcardiographic analyisis. J Electrocardiol 15:221, 1982 3. DePace NL, Colby J, Hakki AH, et al: Poor R wave progression in the precordial leads: Clinical implications for the diagnosis of myocardial infarction. J Am Coll Cardiol 2:1073, 1983 4. Zema MJ, Klingfield PK: ECG poor R wave progression. Arch Intern Med 142:1145, 1982 5. Mittal SR, Srivastava P: Differentiation of poor R wave progression of old anteroseptal myocardial infaction from that due to emphysema. Int J Cardiol 13:92, 1986 6. Hayden GE, Brady WJ, Perron AD, et al: Electrocardiographic T-wave inversion: Differential diagnosis in
10.
11.
12.
13.
14.
Karnath et al. 177
the chest pain patient. Am J Emerg Med 20:252, 2002 Sasaki K, Yotsukura M, Sakata K, et al: Relation of ST-segment changes in inferior leads during anterior wall acute myocardial infarction to length and occlusion site of the left anterior descending coronary artery. Am J Cardiol 87:1340, 2001 de Zwaan C, Bar FW, Wellens HJ: Characteristic electrocardiographic pattern indicating a critical stenosis high in left anterior descending coronary artery in patients admitted because of impending myocardial infarction. Am Heart J 103:730, 1982 Tandy TK, Bottomy DP, Lewis JG: Wellens’ syndrome. Ann Emerg Med 33:347, 1999 Rhinehardt J, Brady WJ, Perron AD, et al: Electrocardiographic manifestations of Wellen’s syndrome. Am J Emerg Med 20:638, 2002 Haines DE, Raabe DS, Gundel WD, et al: Anatomic and prognostic significance of new T-wave inversion in unstable angina. Am J Cardiol 52:14, 1983 Simon K, Hackett D, Szelier A, et al: The natural history of postischemic T-wave inversion: a predictor of poor short-term prognosis? Coron Artery Dis 5:937, 1994 Agetsuma H, Hirai M, Hirayama H, et al: Transient giant negative T wave in acute anterior myocardial infarction predicts R wave recovery and preservation of left ventricular function. Heart 75:229, 1996 Redwood SR, Rerrari R, Marber MS: Myocardial hibernation and stunning: From physiological principles to clinical practice. Heart 80:218, 1998
Electrocardiographic Manifestions of Proximal Left Anterior Descending Artery Occlusion
Bernard M. Karnath, MD, John C. Champion, MD, and Masood Ahmad, MD
Abstract: We report the case of a 51-year-old woman who presents with a 2-week history of episodes of pressure like chest pain. The initial electrocardiogram was not indicative of myocardial ischemia or infarction and the cardiac enzymes remained normal during the initial hospital day. However, the precordial T waves inverted and progressively deepened on the second hospital day and the patient underwent cardiac catheterization with percutaneous coronary angioplasty and stent placement of the left anterior descending coronary artery with good results. The postprocedure electrocardiogram showed complete resolution of the inverted precordial T waves. The development of new T-wave inversions in the precordial leads of patients presenting with unstable angina is predictive of significant stenosis of the left anterior descending coronary artery. This subgroup of patients has a poor prognosis if medical therapy alone is instituted. Early cardiac catheterization and revascularization is recommended for these patients. Evidence has shown that 75% patients with these electrocardiogram changes who are not revascularized developed extensive anterior wall infarction within a few weeks. Key words: Anterior ischemia, Wellen’s Syndrome, T-wave inversions.
The patient is a 51-year-old woman who presents with a 2-week history of episodes of pressure like chest pain. An electrocardiogram (ECG) was obtained in the emergency department and reveals poor R-wave progression and an indeterminate axis (Fig. 1). The patient was admitted for observation with serial cardiac enzymes and ECGs. The cardiac enzymes remained normal. However, T-wave in-
versions became quite evident in the precordial leads on the second hospital day (Fig. 2). An echocardiogram revealed a left ventricular (LV) ejection fraction was 50%. The patient subsequently underwent cardiac catheterization.
Discussion From the Department of Internal Medicine, The University of Texas Medical Branch at Galveston, TX. Reprint requests: Bernard M. Karnath, MD, Department of Internal Medicine, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX 77555-0566. © 2003 Elsevier Inc. All rights reserved. 0022-0736/03/3602-0014$30.00/0 doi:10.1054/jelc.2003.50024
Chest pain is a common presenting complaint in emergency departments. Work up of acute chest pain often includes serial cardiac enzymes and an ECG to rule out ischemic heart disease as an etiology. The ECG is the most commonly used diagnos173
174 Journal of Electrocardiology Vol. 36 No. 2 April 2003
Fig. 1. ECG on admission.
tic tool for patients presenting with symptoms of acute myocardial ischemia. The Presenting ECG The presenting ECG is remarkable for poor Rwave progression, Q waves in V1 and V2, and an
indeterminate axis. The findings in the anterior leads are somewhat suggestive of underlying LAD disease, albeit limited. One study found that the presence of Q waves in leads V1 and V2 indicated a limited apical myocardial infarction with relatively preserved LV function (1). The finding of an indeterminate axis in our patient, defined as equal
Fig. 2. ECG on the second hospital day.
Electrocardiographic Manifestations •
Karnath et al. 175
infarction. One study found that 20% of patients with poor R wave progression had fixed perfusion defects on Thallium-201 myocardial scintigraphy (3). Poor R-wave progression is defined as an Rwave amplitude of 0.3 mv or less in lead V3 combined with a smaller R wave in lead V2 (4). One study showed that the degree of loss of R wave in leads V5 and V6 correlated with a lower LV ejection fraction (1). Our patient had relatively preserved LV function with some mild posterior wall hypokinesis on baseline echocardiogram. Poor R-wave progression is not specific to anterior myocardial infarction, other causes such as emphysema, which can cause a downward displacement of the heart, can cause poor R-wave progression (5).
Development of T-wave Inversions Fig. 3. A wrapped LAD. Arrow indicates apex.
positive and negative components in all 6 frontal plane leads, is nonspecific as there may be many underlying causes (2). Poor R-wave progression is thought to be produced by loss of anterior forces of depolarization due to anteroseptal myocardial scar as a result of
Fig. 4. Pre- and post-PTCA angiograms.
The history of this patient is consistent with myocardial ischemia. The inversions of the precordial T waves are relatively deep and fairly symmetrical, typical of myocardial ischemia. T-wave inversions may be caused by a number of clinical syndromes including acute coronary ischemia, pulmonary embolism, and central nervous system injury (6). The extension of the T-wave inversions to the inferior leads is highly suggestive of a wrapped LAD. A wrapped LAD is defined as an LAD artery
176 Journal of Electrocardiology Vol. 36 No. 2 April 2003
Fig. 5. ECG after PTCA of the LAD lesion.
that perfuses at least one fourth of the inferior wall (7). The cardiac catheterization film shows a partially wrapped LAD (Fig. 3). In the original article by de Zwann et al. (8) in 1982, Dr Wellens warned of impending myocardial infarction in this subset of patients who developed deep T-wave inversions in the precordial leads after the resolution of chest pain. In fact, in their study 75% (12 of 16) of the patients with these ECG changes who were not revascularized developed extensive anterior wall infarction within a few weeks. Wellens’ syndrome, which is characterized by deeply inverted T waves in the precordial leads, is highly suggestive of proximal left anterior descending artery (LAD) stenosis (9). However, not all criteria for Wellen’s syndrome are met in our case. The criteria for Wellen’s syndrome include a history of anginal chest pain combined with T-wave inversions in the anterior chest leads, lack of Q waves and ST-segment elevations, lack of serum marker abnormalities, and normal R-wave progression (10). In our case, the initial ECG shows poor R-wave progression and and Q waves in leads V1 and V2. However, the patient was found to have proximal LAD stenosis with somewhat preserved LV function. The development of new T-wave inversions in the precordial leads of patients presenting with unstable angina is predictive of significant stenosis of the left anterior descending coronary artery with
a reported positive predictive value of 86% (11) this subgroup of patients has a poor prognosis if medical therapy alone is instituted (7). Early cardiac catheterization and revascularization is recommended for these patients (8). For patients with acute ischemic events without infarction, the persistence of inverted T waves is a strong predictor of further ischemic events (12). However, during in acute anterior myocardial infarction, the rapid appearance of giant negative T waves predicts R wave recovery (13). On the other hand, patients who experience resolution of Twave inversions after and ischemic event are less likely to experience further ischemic events (12). Revascularization Ischemic coronary events can result in stunned myocardium in which contractility falls. If the LAD is involved, LV function is likely to be impaired. Revascularization could improve LV function provided that the myocardium is stunned rather than infracted (14). Our patient underwent cardiac catheterization and percutaneous coronary angioplasty (PTCA) with stent placement in the LAD coronary artery on the third hospital day with good results (Fig. 4) The post-procedure ECG shows complete resolution of the inverted precordial T waves (Fig. 5) A follow-up echocardiogram performed 2 months later revealed and ejection fraction of 60%.
Electrocardiographic Manifestations •
Conclusion In a patient presenting with angina, the development of deep T-wave inversions in the setting of poor R-wave progression is highly suggestive of proximal LAD occlusion. The presence of small Q waves in the precordial leads V1 and V2 and presence of R wave forces in leads V5 and V6 is suggestive of limited myocardial infarction with relatively preserved LV function.
7.
8.
9.
References 1. Bogaty P, Boyer L, Rousseau L, et al: Is anteroseptal myocardial infarction an appropriate term? Am J Med 113:37, 2002 2. Goldberger AL: The genesis of indeterminate axis: A quantitative vectorcardiographic analyisis. J Electrocardiol 15:221, 1982 3. DePace NL, Colby J, Hakki AH, et al: Poor R wave progression in the precordial leads: Clinical implications for the diagnosis of myocardial infarction. J Am Coll Cardiol 2:1073, 1983 4. Zema MJ, Klingfield PK: ECG poor R wave progression. Arch Intern Med 142:1145, 1982 5. Mittal SR, Srivastava P: Differentiation of poor R wave progression of old anteroseptal myocardial infaction from that due to emphysema. Int J Cardiol 13:92, 1986 6. Hayden GE, Brady WJ, Perron AD, et al: Electrocardiographic T-wave inversion: Differential diagnosis in
10.
11.
12.
13.
14.
Karnath et al. 177
the chest pain patient. Am J Emerg Med 20:252, 2002 Sasaki K, Yotsukura M, Sakata K, et al: Relation of ST-segment changes in inferior leads during anterior wall acute myocardial infarction to length and occlusion site of the left anterior descending coronary artery. Am J Cardiol 87:1340, 2001 de Zwaan C, Bar FW, Wellens HJ: Characteristic electrocardiographic pattern indicating a critical stenosis high in left anterior descending coronary artery in patients admitted because of impending myocardial infarction. Am Heart J 103:730, 1982 Tandy TK, Bottomy DP, Lewis JG: Wellens’ syndrome. Ann Emerg Med 33:347, 1999 Rhinehardt J, Brady WJ, Perron AD, et al: Electrocardiographic manifestations of Wellen’s syndrome. Am J Emerg Med 20:638, 2002 Haines DE, Raabe DS, Gundel WD, et al: Anatomic and prognostic significance of new T-wave inversion in unstable angina. Am J Cardiol 52:14, 1983 Simon K, Hackett D, Szelier A, et al: The natural history of postischemic T-wave inversion: a predictor of poor short-term prognosis? Coron Artery Dis 5:937, 1994 Agetsuma H, Hirai M, Hirayama H, et al: Transient giant negative T wave in acute anterior myocardial infarction predicts R wave recovery and preservation of left ventricular function. Heart 75:229, 1996 Redwood SR, Rerrari R, Marber MS: Myocardial hibernation and stunning: From physiological principles to clinical practice. Heart 80:218, 1998