This month's post comes courtesy of Dr. Bryan Hayes, our emergency medicine and toxicology pharmacy specialist at the University of Maryland Medical Center. The post is important given its focus on anaphylaxis and the potential adverse effects of epinephrine administration.
http://academiclifeinem.com/epinephrine-dosing-for-anaphylaxis-in-patients-on-beta-blockers/
Thursday, October 31, 2013
Sunday, September 15, 2013
Prehospital ECG's on Amal Mattu's podcast
Check out the following link- Dr. Amal Mattu devotes an entire episode of his ECG blog to prehospital ECGs. The link leads to a brief, 15 minute video on interesting cases transmitted by the Lifepak 12s and 15s of the Baltimore City Fire Department!
Sunday, August 11, 2013
Look Behind You!
A 45 yo female with a history of cigarette smoking and tobacco abuse reports a sudden onset of severe, substernal chest discomfort. EMS providers perform a 12 lead ECG.
ST elevation is noted in leads II, III, and aVF. Reciprocal changes are seen in leads I and aVL. Note ST elevation extends into the lateral precordial leads of V4, V5, and V6. Also of significance is the ST segment depression in leads V2 and V3. Though the R waves aren't especially tall, the ST depression and slightly positive R waves is consistent with extension of the infarction into the heart's posterior wall. A large obstructing lesion of the right coronary artery can affect these geographic areas of the heart. Posterior wall MIs usually do not occur in isolation. The "Life in the Fast Lane" blog has a good page on the interpretation of the posterior wall myocardial infarction.
Inferior lateral ST elevation myocardial infarction with extension into the posterior wall.
12 Lead Discussion
ST elevation is noted in leads II, III, and aVF. Reciprocal changes are seen in leads I and aVL. Note ST elevation extends into the lateral precordial leads of V4, V5, and V6. Also of significance is the ST segment depression in leads V2 and V3. Though the R waves aren't especially tall, the ST depression and slightly positive R waves is consistent with extension of the infarction into the heart's posterior wall. A large obstructing lesion of the right coronary artery can affect these geographic areas of the heart. Posterior wall MIs usually do not occur in isolation. The "Life in the Fast Lane" blog has a good page on the interpretation of the posterior wall myocardial infarction.
12 Lead Interpretation
Inferior lateral ST elevation myocardial infarction with extension into the posterior wall.
Wednesday, April 24, 2013
The Eclectic Equivalent
A 64 yo female calls 911 for chest discomfort. The patient reported chest pressure that waxed and waned in intensity. The discomfort was retrosternal and did not radiate. The patient compared the pressure to previous bouts of "indigestion." The patient experienced associated nausea. No LOC, no diaphoresis. Providers obtain a 12 lead ECG. Vital signs remained stable.
12 Lead ECG
12 Lead ECG Interpretation
The rhythm is sinus and the rate is regular. ST depressions are present in leads II, III, and aVF. There are also ST depressions noted in the precordial leads V3-V6. R wave progression is preserved, and it appears that R waves reach their maximum amplitude in lead V4. There is no obvious ectopy.
ST elevation of > 1 mm is noted in aVR and V1.
Sinus rhythm, diffuse ST segment depression, ST segment elevation in aVR and V1.
Case Discussion
Providers correctly identify the ECG tracing as a potential STEMI equivalent. The STE in aVR and V1 is concerning for its association with acute left main occlusion. The patient was transported to the cardiac cath lab. Cardiologists discovered a near total occlusion of the left main coronary artery.
aVR has long been cast as the "forgotten lead" in electrocardiography. Studies link ST elevation in aVR to left main disease and cardiogenic shock. There is also data to suggest that patients with changes in aVR are more likely to require surgical intervention and progress into cardiogenic shock. Indeed, ST elevation in aVR is often considered a, "STEMI equivalent" due to its association with a poorer prognosis. Always scrutinize all leads of the electrocardiogram for abnormal ST segment morphology. In some studies, STE in aVR that is greater than the STE in V1 distinguishes left main disease from left anterior descending artery disease.
Findings such as STE in aVR are often labeled, "STEMI equivalents." Though not widely recognized as automatic triggers for cath lab activation, these concerning electrocardiographic findings represent time sensitive conditions that benefit from an early interventional approach. Other equivalents include:
References
1. Yamaji H, Iwasaki K, Kusachi S, et al. Prediction of acute left main coronary artery obstruction by 12 lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V1. J Am Coll Cardiol. 2001;38(5):1348-54
2. Nough H, Jorat MV, Varasteravan HR, et al. The value of ST segment elevation in lead aVR for predicting left main coronary artery lesion in patients suspected of acute coronary syndrome. Rom J Intern Med. 2012;50(2):159-64
3. Nikus KC, Eskola MJ. Electrocardiogram patterns in acute left main coronary artery occlusion. J Electrocardiol. 2008;41(6):626-9
12 Lead ECG
12 Lead ECG Interpretation
The rhythm is sinus and the rate is regular. ST depressions are present in leads II, III, and aVF. There are also ST depressions noted in the precordial leads V3-V6. R wave progression is preserved, and it appears that R waves reach their maximum amplitude in lead V4. There is no obvious ectopy.
ST elevation of > 1 mm is noted in aVR and V1.
Sinus rhythm, diffuse ST segment depression, ST segment elevation in aVR and V1.
Case Discussion
Providers correctly identify the ECG tracing as a potential STEMI equivalent. The STE in aVR and V1 is concerning for its association with acute left main occlusion. The patient was transported to the cardiac cath lab. Cardiologists discovered a near total occlusion of the left main coronary artery.
aVR has long been cast as the "forgotten lead" in electrocardiography. Studies link ST elevation in aVR to left main disease and cardiogenic shock. There is also data to suggest that patients with changes in aVR are more likely to require surgical intervention and progress into cardiogenic shock. Indeed, ST elevation in aVR is often considered a, "STEMI equivalent" due to its association with a poorer prognosis. Always scrutinize all leads of the electrocardiogram for abnormal ST segment morphology. In some studies, STE in aVR that is greater than the STE in V1 distinguishes left main disease from left anterior descending artery disease.
Findings such as STE in aVR are often labeled, "STEMI equivalents." Though not widely recognized as automatic triggers for cath lab activation, these concerning electrocardiographic findings represent time sensitive conditions that benefit from an early interventional approach. Other equivalents include:
- Posterior wall MI (ST depression anteriorly)
- New left bundle in association with chest pain/ACS history
- Hyperacute T waves
- The deWinter ST/T complex
- Positive Sgarbossa criteria
References
1. Yamaji H, Iwasaki K, Kusachi S, et al. Prediction of acute left main coronary artery obstruction by 12 lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V1. J Am Coll Cardiol. 2001;38(5):1348-54
2. Nough H, Jorat MV, Varasteravan HR, et al. The value of ST segment elevation in lead aVR for predicting left main coronary artery lesion in patients suspected of acute coronary syndrome. Rom J Intern Med. 2012;50(2):159-64
3. Nikus KC, Eskola MJ. Electrocardiogram patterns in acute left main coronary artery occlusion. J Electrocardiol. 2008;41(6):626-9
Tuesday, April 9, 2013
Where is the Circulatory Road Block?
Case
An 81 y/o female with DM, HTN, and bilateral lower extremity amputations presents to EMS with chest pain and vomiting. VS: BP: 90/40, P: 80, R:16. Sp02: 95%. The patient is alert and oriented and in mild distress. An ECG is obtained. What is your interpretation ?
12 Lead ECG
A first degree AV block is present. Deep Q waves and ST elevations are present in the inferior leads III, and aVF. Additional ST segment elevations are present in the anterior precordial leads V3, V4, and V5. Reciprocal depression is present in leads I and aVL. A right bundle branch block is suggested by the positively deflected QRS and increased QRS duration seen in V1. This patient is experiencing a large STEMI given the presence of elevation in multiple territories. ST elevations suggest active injury and ischemia in the inferior and anterior leads. The relative hypotension may indciate cardiogenic shock. Cardiogenic shock complicates a significant percentage of anterior wall myocardial infarctions. Multi-territorial ST elevations indicates a poor prognosis.
Treatment Course
Providers transmit the 12 lead ECG and alert the receiving facility of an ST elevation myocardial infarction. Aspirin is administered. The patient proceeds directly to the cath lab. The patient had severe, multi-vessel, obstructive coronary artery disease and unfortunately expired from decompensated cardiogenic shock
Key Points
An 81 y/o female with DM, HTN, and bilateral lower extremity amputations presents to EMS with chest pain and vomiting. VS: BP: 90/40, P: 80, R:16. Sp02: 95%. The patient is alert and oriented and in mild distress. An ECG is obtained. What is your interpretation ?
12 Lead ECG
ECG Interpretation
A first degree AV block is present. Deep Q waves and ST elevations are present in the inferior leads III, and aVF. Additional ST segment elevations are present in the anterior precordial leads V3, V4, and V5. Reciprocal depression is present in leads I and aVL. A right bundle branch block is suggested by the positively deflected QRS and increased QRS duration seen in V1. This patient is experiencing a large STEMI given the presence of elevation in multiple territories. ST elevations suggest active injury and ischemia in the inferior and anterior leads. The relative hypotension may indciate cardiogenic shock. Cardiogenic shock complicates a significant percentage of anterior wall myocardial infarctions. Multi-territorial ST elevations indicates a poor prognosis.
Treatment Course
Providers transmit the 12 lead ECG and alert the receiving facility of an ST elevation myocardial infarction. Aspirin is administered. The patient proceeds directly to the cath lab. The patient had severe, multi-vessel, obstructive coronary artery disease and unfortunately expired from decompensated cardiogenic shock
Key Points
- Remain vigilant for the presence of cardiogenic shock in the presence of anterior wall ischemia
- ST elevations in multiple geographic areas (inferior and anterior in this case) indicate severe disease
- Ventricular fibrillation can also accompany large anterior wall MIs
- Relative hypotension is extremely significant in patients who are accustomed to higher blood pressures. In this case, the patient's marginal blood pressure resulted from acutely decreased cardiac output.
Monday, March 11, 2013
Does this young man really need to go to the hospital?!
Case Study
You are dispatched to a 32-year-old male who experienced a syncopal episode while grocery shopping. Upon arrival, you find an awake, alert, and oriented adult male. He apologizes profusely for disturbing you and tells you he is fine. He denies having chest pain, shortness of breath, or unexplained sweating. He states that he skipped breakfast earlier in the day and had quite a bit of alcohol the night before. You explain the importance of checking his vital signs and blood sugar and he agrees to let you check them. His vital signs are: blood pressure 124/74, pulse 62, respirations 18, SpO2 99%, blood sugar 90 mg/dL. His lung sounds are clear, skin cool, dry and pink, abdomen soft and non-tender. Your partner explains the importance of acquiring an ECG and the patient agrees.
You are dispatched to a 32-year-old male who experienced a syncopal episode while grocery shopping. Upon arrival, you find an awake, alert, and oriented adult male. He apologizes profusely for disturbing you and tells you he is fine. He denies having chest pain, shortness of breath, or unexplained sweating. He states that he skipped breakfast earlier in the day and had quite a bit of alcohol the night before. You explain the importance of checking his vital signs and blood sugar and he agrees to let you check them. His vital signs are: blood pressure 124/74, pulse 62, respirations 18, SpO2 99%, blood sugar 90 mg/dL. His lung sounds are clear, skin cool, dry and pink, abdomen soft and non-tender. Your partner explains the importance of acquiring an ECG and the patient agrees.
12-Lead ECG
§ What
is your interpretation?
§ Do
you see anything life-threatening?
§ What
is your next course of action?
§ Does
this patient need to be transported to the hospital?
Case Study Summary
The ECG reveals a sinus rhythm. There are no signs of chamber enlargement, axis
deviation, or myocardial ischemia. Close inspection of leads V1-V2 reveals an incomplete right bundle branch
block (rSR’ pattern), ST segment elevation, and T wave inversion, consistent
with Brugada Syndrome.
Brugada
Syndrome is a genetic condition involving a sodium channel abnormality in the
heart’s cells. The disease causes ventricular tachydysrhythmias that may lead
to syncope or sudden death. The disease primarily affects males and is most
commonly discovered in the third or fourth decade of life. Brugada Syndrome is
reported to cause 5% of all sudden cardiac arrest cases.
This
patient should be transported to the emergency department for further
evaluation. Treatment for Brugada Syndrome includes electrophysiologic testing
and placement of an automated implantable cardioverter-defibrillator.
Clinical Pearls
§ Never
dismiss syncope in the prehospital setting.
§ Acquire
a 12-Lead ECG on all patients presenting with presyncope or syncope and
scrutinize the tracing for changes consistent with life-threatening diseases.
§ Brugada
Syndrome is characterized by:
§ An
incomplete right bundle branch block (rSR’ pattern in leads V1-V2).
§ ST
segment elevation in leads V1-V2.
§ T
wave inversion in leads V1-V2.
Suggested Readings
Syncope–http://emedicine.medscape.com/article/811669-overview
Brugada Syndrome–http://emedicine.medscape.com/article/163751-overview
Tuesday, February 19, 2013
Syncopation and Strain
EMS is inbound with a 50 yo male patient. The patient reports shortness of breath and diaphoresis. He was feeling a bit lightheaded and passed out for approximately 30 seconds prior to calling 911. The patient denies other trauma or recent illness. The patient has noted some increasing dyspnea on exertion during the past week. The onset of symptoms occurred without warning or provocation. EMS acquires a 12 lead ECG. A nurse onscene advised that the patient was hypotensive and "clammy" following the syncopal episode.
PMHX:
Hypertension
Dyslipidemia
Appendectomy
Vitals:
BP: 110/70
P: 131
R: 22
Sp02: 95%
12 Lead ECG:
12 Lead ECG Interpretation and Discussion:
The rate is tachycardic at approximately 140 beats per minute and regular. The RSR' morphology and duration of the QRS complex in V1 suggests the presence of a right bundle branch block. The terminal R wave in V1, the slurred S wave in V6, and the inverted T waves in aVL and V1 are expected in the setting of a bundle branch block. It is difficult to discern p waves though there may be a retrograde P waves present in leads III and V2. Tachycardia and right bundle branch block suggest the presence of "right heart strain."
Final interpretation:
Supraventricular tachycardia, rate of 140/min. Right bundle branch block. Electrocardiographic evidence of right heart strain.
Emergency department course:
Supplemental oxygen was administered. A bedside echocardiogram revealed a dilated right ventricle. There was no pericardial effusion. A portable chest xray was without any obvious abnormality. The patient received an infusion of unfractionated heparin and underwent multi-detector CT angiography of the chest. The patient was found to have bilateral, segmental pulmonary embolisms.
Pulmonary embolism:
A pulmonary embolism, or "PE", may be extremely difficult to diagnose. Patients present with a wide variety of symptoms, and not all pulmonary embolisms result in persistent vital sign abnormalities. Providers should have a low suspicion for pulmonary embolism in patients with tachypnea, tachycardia, and pleuritic chest pain. Syncope is a concerning complaint and can be effectively evaluated with a 12 lead electrocardiogram. In this case, the syncope resulted from the patient's clot burden. A sub-massive pulmonary embolism can reduce preload and compromise cardiac output.
Syncope? Get the 12 lead!
PMHX:
Hypertension
Dyslipidemia
Appendectomy
Vitals:
BP: 110/70
P: 131
R: 22
Sp02: 95%
12 Lead ECG:
12 Lead ECG Interpretation and Discussion:
The rate is tachycardic at approximately 140 beats per minute and regular. The RSR' morphology and duration of the QRS complex in V1 suggests the presence of a right bundle branch block. The terminal R wave in V1, the slurred S wave in V6, and the inverted T waves in aVL and V1 are expected in the setting of a bundle branch block. It is difficult to discern p waves though there may be a retrograde P waves present in leads III and V2. Tachycardia and right bundle branch block suggest the presence of "right heart strain."
Final interpretation:
Supraventricular tachycardia, rate of 140/min. Right bundle branch block. Electrocardiographic evidence of right heart strain.
Emergency department course:
Supplemental oxygen was administered. A bedside echocardiogram revealed a dilated right ventricle. There was no pericardial effusion. A portable chest xray was without any obvious abnormality. The patient received an infusion of unfractionated heparin and underwent multi-detector CT angiography of the chest. The patient was found to have bilateral, segmental pulmonary embolisms.
Pulmonary embolism:
A pulmonary embolism, or "PE", may be extremely difficult to diagnose. Patients present with a wide variety of symptoms, and not all pulmonary embolisms result in persistent vital sign abnormalities. Providers should have a low suspicion for pulmonary embolism in patients with tachypnea, tachycardia, and pleuritic chest pain. Syncope is a concerning complaint and can be effectively evaluated with a 12 lead electrocardiogram. In this case, the syncope resulted from the patient's clot burden. A sub-massive pulmonary embolism can reduce preload and compromise cardiac output.
Syncope? Get the 12 lead!
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