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Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018
| Contributor Information
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Tracing (case 124) courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
Most physicians are very comfortable with the classic electrocardiographic (ECG) findings of ST changes, T-wave inversions, and Q waves in myocardial ischemia or infarction. However, the subtle myocardial infarction (MI) may be easily overlooked, especially in patients with underlying ECG abnormalities. The tracing shown demonstrates anterior ischemia with an underlying left bundle branch block (LBBB), an abnormality that typically excludes the diagnosis of an MI.
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 12) courtesy of ECG Wave-Maven/Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing shows an LBBB with an MI. LBBBs make elevations or depressions in the precordial leads unreliable, often masking an MI. An LBBB can be identified by the widened QRS, the notched R wave in lead V6, and the rS complex in lead V1. Additionally, the T waves should be opposite the terminal deflection of the QRS complex.[1] This tracing also demonstrates biphasic and inverted T waves in leads III and aVF (arrows) that are in the same terminal deflection as the QRS complex, suggesting inferior ischemia. These findings are specific, but not particularly sensitive, for ischemia or infarction.
Tracing (case 95) courtesy of ECG Wave-Maven/Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing is another example of an LBBB with a likely prior MI as well as an ongoing MI. The Q waves in leads I and V6 (black arrows) and the notched S wave in leads V2 and V3 (red arrow) suggest a previous MI. A notching in the first 0.04 seconds of the ascending limb of the S wave in lead V3 or V4 in a tracing with an LBBB also suggests a previous MI and is referred to as the Cabrera sign. The biphasic T waves in leads V2, V3, and V4 with a component in parallel to the terminal deflection of the QRS complex suggest current ischemia (blue arrows).
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 20) courtesy of ECG Wave-Maven/Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing demonstrates a right bundle branch block (RBBB) with an acute MI. Similar to an LBBB, the T waves in an RBBB should be opposite the terminal deflection of the QRS complex. An RBBB can be identified by a widened QRS, an rSR' pattern (in which there is a second abnormal deflection of the R wave) in lead V1, and a slurred s wave in the qRs of leads I and V6.[2] This tracing shows replacement of the rSR' pattern with a qR pattern in leads V1, V2, and V3 (black arrows), which is pathologic if seen past lead V2. Upright T waves are seen parallel to the terminal deflection of the QRS complex in leads V2, V3, and V4 (blue arrows). ST-segment elevations are also seen in leads V2, V3, and V4 (red arrows). These findings all suggest anterior septal ischemia or infarction.
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 24) courtesy of ECG Wave-Maven/Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
Ventricular paced rhythms, like bundle branch blocks, are often not interpretable for cardiac ischemia. In this tracing, there is complete heart block with a ventricular paced rhythm. ST elevations can still be appreciated in the inferior and lateral leads (black arrows) with concomitant depressions in the anterior leads (blue arrows) that are consistent with inferoposterolateral ischemia. Significant elevations in the inferior or right precordial leads and ST depression or T-wave inversions in leads with QS or rS complexes suggest ischemia.[3]
Tracing (case 108) courtesy of ECG Wave-Maven/Seth McClennen, MD, and Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing is another example of a paced rhythm with an underlying MI. The rhythm strip shows both A-V sequential pacing and A-sensed V-paced rhythms. There are significant elevations in the inferior leads (black arrows), with reciprocal ST depressions (blue arrows) suggesting an inferior MI.
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 264) courtesy of ECG Wave-Maven/Diane L. Perry, CCT, and Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing shows bigeminal premature ventricular complexes (PVCs) with underlying ischemia. There are ST elevations in leads I and aVL (black arrows) with reciprocal ST depressions in leads III and aVF (blue arrows) that are consistent with an anterolateral MI. Because of the bigeminal PVCs, these changes are only appreciated every other beat and could be easily overlooked as a result of the PVC morphology.
Tracing (case 362) courtesy of ECG Wave-Maven/Diane L. Perry, CCT, David Leeman, MD, and Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing is another example of ischemia with ventricular premature beats (VPBs) in a bigeminal pattern. The alternating sinus beats show ST elevations in the inferior leads (black arrows) with reciprocal ST depressions in the anterolateral leads (blue arrows) that are consistent with inferior ischemia.
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 11) courtesy of ECG Wave-Maven/Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing demonstrates an ongoing or recent anterior myocardial ischemia in a patient with chest pain 2 days earlier and only mildly elevated cardiac markers. There are significant T-wave inversions in the anterior precordial leads (black arrows) without the presence of Q waves or ST depressions/elevations. Prominent T-wave inversions can also be caused by central nervous system disease, apical hypertrophic cardiomyopathy, stress cardiomyopathy, and intermittent right ventricular pacing or intermittent LBBB. Other findings on this tracing are mild PR- and QT-interval prolongation and left ventricular hypertrophy.
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 39) courtesy of ECG Wave-Maven/Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing demonstrates lateral wall ischemia that could easily be confused with normal variant early repolarization. There are ST elevations in leads V4, V5, and V6 (black arrows) with subtle reciprocal ST depressions in leads V2 and V3 (blue arrows). Early repolarization may be found in a similar lead distribution, but there is usually a more prominent concave upward component with larger T waves. There are never reciprocal ST depressions with early repolarization. The tracing also shows some incidental Q waves in leads II and aVF, which suggest an older MI.
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 410) courtesy of ECG Wave-Maven/Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing shows myocardial ischemia from occlusion of the left anterior descending artery. There are T-wave inversions in leads V2, V3, and V4 (black arrows) with biphasic T waves in leads I, aVL, and V5 (blue arrows). This pattern is referred to as Wellens syndrome or Wellens T waves, which is caused by critical narrowing of the proximal left anterior descending artery. Tracings must show progressive deep T-wave inversions in leads V2 and V3, a steep 60°-90° slope to the T waves, no discrete ST-segment elevations, and no loss of the precordial R waves.[4]
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 98) courtesy of ECG Wave-Maven/Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing demonstrates an inferior MI with low voltages in the limb leads. Low voltages can make the findings of an MI much more difficult to detect. In the inferior leads, there are slight ST elevations (black arrows) and T-wave inversions (blue arrows) with reciprocal ST depressions in lead aVL (red arrow).
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 331) courtesy of ECG Wave-Maven/Diane L. Perry, CCT, and Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing demonstrates an inferolateral MI. There are ST elevations in the inferior and lateral leads (black arrows) with reciprocal ST depressions in leads aVL, V1, and V2 (blue arrows). Occlusion of the right coronary artery or the left circumflex artery can cause inferolateral ischemia. A right coronary artery occlusion is more likely when the ST elevations in lead III are greater than those in lead II and when there are no ST elevations in lead I.
Tracing (case 376) courtesy of ECG Wave-Maven/Michael Chuang, MD, and Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing is another example of an inferior MI from a right coronary artery lesion over a circumflex artery lesion. The ST elevation in lead III (black arrow) is greater than the one in lead II (blue arrow), and there is no ST elevation in lead I (red arrow).
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here?
Tracing (case 470) courtesy of ECG Wave-Maven/Michael Chuang, MD, and Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
This tracing demonstrates an acute lateral ST elevation MI. There is prominent ST elevation in V5 and V6 (black arrows) and reciprocal changes with ST depressions in V1 through V4 (red arrows). ST depressions in V1 through V4 should be considered in the context of other ST changes to rule out anterior subendocardial ischemia.
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here in a patient with a recent bypass surgery?
Tracing (case 371) courtesy of ECG Wave-Maven/Michael Chuang, MD, and Ary L. Goldberger, MD.
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
There is an isolated premature ventricular beat (black arrow). There are ST elevations in I (red arrow) and aVL with reciprocal depressions in III and aVF (blue arrow). The patient was found to have an in-stent thrombosis to the saphenous vein graft.
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
What is the ECG abnormality shown here? (Leads V1-V6 are actually V1R through V6R)
Tracing courtesy of Nathanson LA, McClennen S, Safran C, Goldberger AL. ECG Wave-Maven: Self-Assessment Program for Students and Clinicians (http://ecg.bidmc.harvard.edu).
Are You Missing Subtle MI Clues on ECGs? Test Your Skills
Lars Grimm, MD, MHS | April 25, 2018 | Contributor Information
There is an acute inferior/posterior/lateral MI with ST elevations in II (black arrow), III, and aVF, V5, and V6, with corresponding depressions are seen in V1-V3. Note that the right-sided chest leads show normal R wave progression (red arrows) because the patient has situs inversus-type dextrocardia. The limb leads looks like they have been reversed but they have not.[5]
Clinical manifestations of aortic dissection are often missed on initial evaluation. Is there a 'can't miss' combination of signs and symptoms to correctly identify these dangerous tears?Slideshows, October 2017
Myocardial infarction (MI) (ie, heart attack) is the irreversible death (necrosis) of heart muscle secondary to prolonged lack of oxygen supply (ischemia). Approximately 1.5 million cases of MI occur annually in the United States.Diseases/Conditions, February 2018
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Contributor Information
Author
Lars Grimm, MD, MHS
Assistant Professor
Department of Diagnostic Radiology
Duke University Medical Center
Durham, North Carolina
Disclosure: Lars Grimm, MD, MHS, has disclosed no relevant financial relationships.
Editor
John A McPherson, MD
Assistant Professor of Medicine
Division of Cardiovascular Medicine
Vanderbilt University School of Medicine
Nashville, Tennessee
Disclosure: John A McPherson, MD, has disclosed no relevant financial relationships.
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References
Scherbak D, Hicks GJ. Rhythm, Bundle Branch Block, Left (LBBB). StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018.
Xiang L, Zhong A, You T, et al. Prognostic Significance of Right Bundle Branch Block for Patients with Acute Myocardial Infarction: A Systematic Review and Meta-Analysis. Med Sci Monit. 2016 Mar 27;22:998-1004.
Karumbaiah K, Omar B. ST-elevation myocardial infarction in the presence of biventricular paced rhythm. J Emerg Med. 2013 Aug;45(2):e35-40.
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