STEMI Limitations

STEMI Limitations

In 2000, the ST-Elevation Myocardial Infarction (STEMI) paradigm revolutionized the management of Acute Coronary Syndrome (ACS), substituting the previous dichotomy between Q-wave versus non-Q wave myocardial infarcts (MI). Subcategorizing aimed to predict completely occluded arteries and the need for immediate intervention, namely, emergent cardiac catheterization to open an occluded coronary artery in STEMI. However, literature has shown that STEMI and occlusion myocardial infarction (OMI) are not interchangeable, with clear evidence of benefit from early reperfusion in both entities. Moreover, definitions STEMI and Non-ST-elevation myocardial (NSTEMI) can miss a large proportion of acute coronary occlusions; STEMI as a category can miss 30% of occlusion MI up to 50% in left circumflex, and NSTEMI was only associated with total MI in a quarter of cases.

As any Emergentologist at any level can relate, it was only recently when my ED held a morbidity and mortality meeting for a presumably delayed cath lab activation. The patient had all the risk factors, a typical chest pain which resolved in the ED, normal vitals and an ECG that didn’t meet the STEMI criteria; however, when he went for urgent angiography, the LAD was totally occluded.

A new paradigm: OMI vs. NOMI

The OMI manifesto, introduced by Dr Stephen Smith, Dr Pendell Myers, and Dr Scott Weingart might provide a better solution in the management of ACS. The fundamental question is: Does the patient have an acute coronary occlusion that would benefit from immediate intervention? Based on this question, the following diagram was suggested to substitute STEMI versus NSTEMI paradigm. The manifesto also contains rules to diagnose acute MI in certain categories of patients, such as patients with left bundle branch block (LBBB), left ventricular paced rhythm, terminal QRS distortion, normal ST-elevation vs. left anterior descending artery (LAD) occlusion, anterior ventricular aneurysm vs. acute MI, ST depression in aVL.

Basic concepts

ACS is a spectrum of clinical presentations divided into STEMI, NSTEMI and unstable angina, based on ECG findings and cardiac markers. The American Heart Association/American College of Cardiology (AHA/ACC) and European Society of Cardiology (ESC) define STEMI as new ST elevation at the J point in the absence of LV hypertrophy or LBBB in at least 2 contiguous leads. The elevation must be at least 2 mm (0.2 mV) in men or 1.5 mm (0.15 mV) in women in leads V2–V3 and/or 1 mm (0.1 mV) in other contiguous chest leads or the limb leads.

AHA/ACC recommends primary percutaneous coronary intervention (PCI) for patients with STEMI and ischemic symptoms of less than 12 hours’ duration. In NSTEMI, the recommendation is to perform urgent/immediate angiography with revascularization if appropriate in patients who have refractory angina or hemodynamic or electrical instability.

A meta-analysis of 46 trials with a total of 37 757 patients, including data from the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) and Complete versus Culprit-Only Revascularization Strategies to Treat Multi-vessel Disease after Early PCI for STEMI (COMPLETE) trials demonstrated that PCI prevents death, cardiac death, and MI in patients with unstable coronary artery disease (CAD). The study defined unstable CAD as post-MI patients who haven’t received reperfusion therapy, multi-vessel disease following STEMI, non–ST-segment–elevation acute coronary syndrome.

STEMI Equivalents

For patients with persistent chest pain, hemodynamic instability and certain patterns of EKGs, it’s advisable to consider immediate/urgent PCI. The following patterns were found consistent with total occlusion or critical ischemia of the coronaries so every Emergentologist should familiarize her/himself with those: (All displayed ECGs are from Life in the Fast Lane ECG library)

De Winter T-wave: LAD occlusion.

Prominent T wave with upsloping ST depression in precordial leads
Prominent T wave with upsloping ST depression in precordial leads. https://litfl.com/de-winter-t-wave-ecg-library/

Wellen's Syndrome: Severe proximal LAD stenosis.

Biphasic or deep inverted T waves in V2 V3
Biphasic or deep inverted T waves in V2 V3 https://litfl.com/wellens-syndrome-ecg-library/

LBBB with positive Sgarbossa criteria

New LBBB without meeting Sgarbossa criteria is not considered an indication for cath lab activation any longer. Smith modified Sgarbossa criteria are:

  • Concordant ST elevation ≥ 1 mm in ≥ 1 lead
  • Concordant ST depression ≥ 1 mm in ≥ 1 lead of V1-V3
  • Proportionally excessive discordant STE in ≥ 1 lead anywhere with ≥ 1 mm STE, as defined by ≥ 25% of the depth of the preceding S-wave

Positive Sgarbossa criteria in ventricular paced rhythm

Posterior MI: Left Circumflex (LCx) Artery or right coronary artery (RCA) occlusion

Infero-lateral STEMI with ST depression in V1 to V4 suggesting posterior MI
Infero-lateral STEMI with ST depression in V1 to V4 suggesting posterior MI https://litfl.com/posterior-myocardial-infarction-ecg-library/
Same patient with posterior EKG showing ST elevation in posterior leads
Same patient with posterior EKG showing ST elevation in posterior leads https://litfl.com/posterior-myocardial-infarction-ecg-library/

Right Ventricular MI: Complicates inferior STEMI, RCA occlusion

ST elevation in V1, ST elevation in III more than II
ST elevation in V1, ST elevation in III more than II https://litfl.com/right-ventricular-infarction-ecg-library/

ST elevation in aVR with diffuse ST depression: Left Main Coronary Artery (LMCA), proximal LAD, or triple vessel occlusion

ST elevation in aVR with diffusion ST depression
ST elevation in aVR with diffusion ST depression https://litfl.com/st-elevation-in-avr/

ST depression and T-wave inversion in aVL: RCA, LCx, or LAD occlusion

Reciprocal ST depression in avL
Reciprocal ST depression in avL https://litfl.com/inferior-stemi-ecg-library/

Hyperacute T-waves: LCx occlusion

Broad asymmetrical T wave
Broad asymmetrical T wave https://litfl.com/t-wave-ecg-library/

References and Further Reading

  • Amsterdam, E. A., Wenger, N. K., Brindis, R. G., Casey, D. E., Ganiats, T. G., Holmes, D. R., … & Zieman, S. J. (2014). 2014 AHA/ACC guideline for the management of patients with non–ST-elevation acute coronary syndromes. Journal of the American College of Cardiology, 64(24), e139-e228.
  • Chacko, L., P. Howard, J., Rajkumar, C., Nowbar, A. N., Kane, C., Mahdi, D., … & Ahmad, Y. (2020). Effects of percutaneous coronary intervention on death and myocardial infarction stratified by stable and unstable coronary artery disease: a meta-analysis of randomized controlled trials. Circulation: Cardiovascular Quality and Outcomes, 13(2), e006363.
  • Coven, D. L. (2020). Acute Coronary Syndrome. Retrieved April 9, 2021, from https://emedicine.medscape.com/article/1910735-overview
  • Khan, A. R., Golwala, H., Tripathi, A., Bin Abdulhak, A. A., Bavishi, C., Riaz, H., … & Bhatt, D. L. (2017). Impact of total occlusion of culprit artery in acute non-ST elevation myocardial infarction: a systematic review and meta-analysis. European heart journal, 38(41), 3082-3089.
  • Kreider, D., Berberian, J. (2019). STEMI Equivalents: Can’t-Miss Patterns. EMResident. Retrieved April 9, 2021, from https://www.emra.org/emresident/article/stemi-equivalents/
  • Life in the Fast Lane. (n.d.). ECG Library. Retrieved April 9, 2021, from https://litfl.com/ecg-library/
  • Meyers, P. (2018). Guest Post – Down with STEMI – The OMI Manifesto by Pendell Meyers. EM Crit RACC. Retrieved April 9, 2021, from https://emcrit.org/emcrit/omi-manifesto/
  • O’gara, P. T., Kushner, F. G., Ascheim, D. D., Casey Jr, D. E., Chung, M. K., De Lemos, J. A., … & Zhao, D. X. (2013). 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction. Circulation, 127(4), 529-555.
  • Wang, T. Y., Zhang, M., Fu, Y., Armstrong, P. W., Newby, L. K., Gibson, C. M., … & Roe, M. T. (2009). Incidence, distribution, and prognostic impact of occluded culprit arteries among patients with non–ST-elevation acute coronary syndromes undergoing diagnostic angiography. American heart journal, 157(4), 716-723.
Cite this article as: Israa M Salih, UAE, "STEMI Limitations," in International Emergency Medicine Education Project, May 31, 2021, https://iem-student.org/2021/05/31/stemi-limitations/, date accessed: September 24, 2021

Recent Blog Posts By Israa Salih

Basic ECG Illustrations

basic ecg illustrations

ECG Basics

ECG Waves

 

Intervals and Segments

 

References and Further Reading

1. ECG Rate Interpretation 2. ECG Rhythm Evaluation 3. ECG Axis Interpretation 4. P wave 5. Q wave 6. R wave 7. T wave 8. U wave 9. PR interval 10. QT interval 11. ST Segment 12. QRS complex    
Cite this article as: Murat Yazici, Turkey, "Basic ECG Illustrations," in International Emergency Medicine Education Project, February 24, 2021, https://iem-student.org/2021/02/24/basic-ecg-illustrations/, date accessed: September 24, 2021

Recent Blog Posts by Murat Yazici

Question Of The Day #18

question of the day
qod18
839 - diffuse ST elevation - pericarditis?

Which of the following is the most appropriate next step in management for the patient’s condition?

This patient presents to the emergency department with signs and symptoms consistent with acute pericarditis from a likely viral etiology. Common causes of acute pericarditis include idiopathic, infectious (viral, bacterial, or fungal), malignancy, drug-induced, rheumatic disease-associated (lupus, rheumatoid arthritis, etc.), radiation, post-MI (Dressler’s Syndrome), uremia, and severe hypothyroidism. The chest pain associated with this diagnosis is typically worse with supine positioning, improved with sitting forward, worse with inspiration, and may radiate to the back. A pericardial friction rub may be heard on auscultation of the chest, and there may be a low-grade fever on the exam. The hallmark EKG demonstrates diffuse ST-segment elevation with PR segment depression, although normal ST segments or T wave inversions can be seen on EKG later in the disease process. The treatment of acute pericarditis depends on the underlying cause of the disease. This patient has likely viral pericarditis with no clinical signs of myocarditis (i.e. fluid overload, cardiogenic shock, etc.) or cardiac tamponade (i.e. obstructive shock, distended neck veins, muffled heart sounds, low voltage QRS complexes or electrical alternans on EKG). A cardiac sonogram would be prudent to evaluate for a pericardial effusion. This patient’s disease course likely will resolve with NSAIDs in 1-2 weeks. Ibuprofen (Choice C) is the preferred treatment over aspirin (Choice A) or steroids (Choice B). Colchicine (Choice D) can be useful in recurrent episodes of pericarditis to reduce recurrence and in acute pericarditis not responding to NSAIDs. Correct Answer: C 

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #18," in International Emergency Medicine Education Project, October 23, 2020, https://iem-student.org/2020/10/23/question-of-the-day-18/, date accessed: September 24, 2021

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Question Of The Day #14

question of the day
question of the day 14
40.1 - Pneumothorax 1

Which of the following is the most appropriate treatment for this patient’s condition?

Anticoagulation (Choice A) would be the proper treatment for pulmonary embolism, NSTEMI/STEMI, and other conditions. This patient is dyspneic and hypoxemic on the exam, but his chest X-ray offers an alternative explanation for his symptoms. IV antibiotics (Choice D) would be helpful for pneumonia and COPD exacerbation, both of which are possible in this patient, but his chest X-ray offers an alternative explanation for his symptoms. Needle decompression of the left chest (Choice B) would be the appropriate initial treatment for a left-sided “tension” pneumothorax. This patient does have a large left-sided pneumothorax, but the X-ray lacks tracheal deviation, mediastinal shift, and left hemidiaphragm flattening, which can be attributed to tension pneumothorax. Most importantly, the patient lacks the hemodynamic instability that defines tension physiology (i.e. hypotension and tachycardia). In addition, the diagnosis and treatment of tension pneumothorax should be made clinically prior to chest radiography. Signs of hemodynamic instability along with tracheal deviation, absent unilateral lung sounds, and a history of trauma all support a diagnosis of tension pneumothorax. The treatment of a tension pneumothorax requires prompt recognition, needle decompression at the 3rd intercostal space at the midclavicular line, and a tube thoracostomy at the 4-5th intercostal space the anterior axillary line. The recommended needle decompression location is recently shifted to 4-5th intercostal space at the mid-anterior axillary line because the studies showed lower success rates in anterior – mid clavicular approach in adults. This patient has a spontaneous left-sided pneumothorax, not a tension pneumothorax. This is likely secondary to his coughing episodes and severe COPD. The treatment for this would be supplemental oxygen and the placement of a small-bore chest tube (i.e. “pig tail) in the left chest. Correct Answer: C. 

References

Smith LM, Mahler SA. Chest Pain. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219641169

Nickson, C. (2019) Pneumothorax CCC. Life in the Fastlane. Accessed August 17, 2020. https://litfl.com/pneumothorax-ccc/

Cite this article as: Joseph Ciano, USA, "Question Of The Day #14," in International Emergency Medicine Education Project, September 25, 2020, https://iem-student.org/2020/09/25/question-of-the-day-14/, date accessed: September 24, 2021

Question Of The Day #13

question of the day
qod13

Which of the following is the most appropriate next step in management for this patient’s condition?

This patient presents to the emergency department after an atypical, brief episode of chest pain. The list of potential diagnoses that may have caused the pain episodes is extensive. The focus of the Emergency Medicine practitioner should not be to determine the diagnosis per say, but rather to be to identify the presence of any life-threatening conditions (i.e. Myocardial infarction, Aortic dissection, Esophageal Rupture, Pulmonary embolism, Tension pneumothorax, Cardiac tamponade, etc.). Many of these serious diagnoses can be evaluated with a detailed history, physical exam, and basic imaging and lab work if needed. Many risk stratification tools have been developed to evaluate the likelihood a patient has chest pain due to Acute Coronary Syndrome. One well-supported tool with international validation is the HEART score tool. The HEART score categorizes a patient as low (0-3), moderate (4-6), or high risk (7-10) for a Major Adverse Cardiac Event (MACE) based on the patient’s history, EKG, age, risk factors, and troponin level. The below chart from Wieters et al. (2020) outlines the HEART score categories and how to make clinical decisions based on a patient’s score.

HEART score for cardiac risk assessment of major adverse cardiac event (MACE).

CategoryScoreExplanationRisk Features
HistoryHigh-risk features
• Middle- or left-sided chest pain
• Heavy chest pain
• Diaphoresis
• Radiation
• Nausea and vomiting
• Exertional
• Relief of symptoms by sublingual nitrates

Low-risk features
• Well localized
• Sharp pain
• Non-exertional
• No diaphoresis
• No nausea and vomiting
Slightly Suspicious 0Mostly low-risk features
Moderately Suspicious+1Mixture of high-risk and low-risk features
Highly Suspicious+2Mostly high-risk features
ECG
Normal0Completely Normal
Non-specific Repolarization Disturbance+1Non-specific repolarization disturbance• Repolarization abnormalities
• Non-specific T wave changes
• Non-specific ST wave depression or elevation
• Bundle branch blocks
• Pacemaker rhythms
• Left ventricular hypertrophy
• Early repolarization
• Digoxin effect
Significant ST Depression+2Significant ST depression• Ischemic ST-segment depression
• New ischemic T wave inversions
Age
<450
45-64+1
≥ 65+2
Risk Factors• Obesity (Body-Mass Index ≥ 30)
• Current or recent (≤ 90 days)smoker
• Currently treated diabetes mellitus
• Family history of coroner artery disease (1st degree relative < 55 year old)
• Hypercholesterolemia

OR

Any history of atherosclerotic disease earn 2 points:
• Know Coroner artery Disease: Prior myocardial infarctions, percutan coronary intervention (PCI) or coronary artery bypass graft
• Prior stroke or transient ischemic attack
• Peripheral arterial disease
No known risk factors0
1-2 risk factors+1
≥ 3 risk factors or history of atherosclerotic disease+2
Initial Troponin
≤ normal limit0
1-3 x normal limit+1
> 3x normal limit+2

Score 0–3 = 2.5 % MACE over next 6 wk: Discharge home
Score 4–6 = 22.3% MACE over next 6 wk: Admit for observation
Score 7–10 = 72.7% MACE over next 6 wk: Admit with early invasive strategies

The patient’s HEART score in this question would be 2 (1 point for age and 1 point for hypertension as a risk factor). This categorizes the patient as low risk for a MACE over the next six weeks. The appropriate course of action for this patient would be discharge home with prompt outpatient follow-up (Choice B). Admission for cardiac testing (Choice D) would be warranted for a moderate-high risk HEART score. Prescribing a benzodiazepine (Choice C) would not be warranted as this patient is asymptomatic and the pain episode is vague and atypical. Benzodiazepines are sometimes useful in patients with chest pain due to anxiety. Cardiology consultation (Choice A) would not be warranted as the patient has a low HEART score, is currently asymptomatic with normal imaging, blood work and troponin, and a normal EKG. Correct Answer: B 

References

Smith LM, Mahler SA. Chest Pain. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219641169

Wieters J, McDonough J, Catral J. Chest Pain. In: Stone C, Humphries RL. eds. CURRENT Diagnosis & Treatment: Emergency Medicine, 8e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2172&sectionid=165059275

Cite this article as: Joseph Ciano, USA, "Question Of The Day #13," in International Emergency Medicine Education Project, September 18, 2020, https://iem-student.org/2020/09/18/question-of-the-day-13/, date accessed: September 24, 2021

Question Of The Day #12

question of the day

Which of the following medications should be avoided to prevent worsening of this patient’s condition?

This elderly female patient presents with chest pain described as post-prandial burning, radiating to the shoulders, and with associated nausea and diaphoresis. Burning chest pain after eating supports diagnoses, such as peptic ulcer disease, gastritis, gastroesophageal reflux, or biliary disease. However, chest pain that radiates to both shoulders (2.58 likelihood ratio) or has associated diaphoresis (1.50 likelihood ratio) should be very concerning for acute myocardial infarction (Smith & Mahler, 2020). Associated symptoms that should raise concern for acute coronary syndrome are any radiation of the chest pain, pain worsened with exertion, associated nausea or vomiting, pain described as pressure or squeezing, pain with associated diaphoresis, and pain described as feeling similar to prior ischemic events. This patient’s EKG demonstrates an inferior ST-segment elevation myocardial infarction (STEMI). This is indicated by two or more inferior EKG leads (II, III, and aVF) showing ST-segment elevation greater than 1 mm and reciprocal ischemic changes indicated in lateral leads (I, aVL). Aspirin (Choice A) should be given to all patients with high suspicion for ACS, assuming there are no contraindications. This patient has a confirmed STEMI on her EKG and should receive Aspirin for its antiplatelet effects. Ibuprofen (Choice B) may help the patient’s pain, but likely would not acutely worsen the patient’s clinical condition. Antacids (Choice C) are relatively benign medications, and they would be unlikely to worsen the patient’s clinical condition. Nitroglycerin (Choice D) is often given in patients with anginal chest pain for pain relief. In many inferior STEMIs, nitroglycerin can cause a dangerous drop in blood pressure and should be avoided. These patients may have infarction of the right ventricle, which makes these patients sensitive to nitrates and prone to precipitous drops in blood pressure. IV fluids are the preferred initial therapy in the setting of hypotension. About 40% of patients with an inferior STEMI have concurrent right ventricular infarction. About 80% of inferior STEMIs are caused by occlusions in the right coronary artery (RCA) and about 18% are from an occlusion in the left circumflex artery (LCx). Occluded vessels in both territories can cause right ventricular infarction. Correct Answer: D  

References

Smith LM, Mahler SA. Chest Pain. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219641169

Burns, E. (2019) Inferior STEMI. Life in the Fast Lane. Accessed August 17, 2020. https://litfl.com/inferior-stemi-ecg-library/

Cite this article as: Joseph Ciano, USA, "Question Of The Day #12," in International Emergency Medicine Education Project, September 11, 2020, https://iem-student.org/2020/09/11/question-of-the-day-12/, date accessed: September 24, 2021

Hypokalemic Periodic Paralysis in the ED

Hypokalemic Periodic Paralysis in the ED

Case Presentation

A middle-aged man with a two days history of weakness in his legs. The patient works as a construction worker and is used to conducting heavy physical activity.

After a thorough history and examination, the weakness was reported in the lower extremities with a power of 2/5, whereas the power in upper extremities was 4.5/5, Achilles tendon reflex was reduced, plantar response and other reflexes were intact, with normal sensation. Rest of the examination is unremarkable.

The vitals are within normal ranges, Blood investigations include – Urea and electrolytes, liver and renal function, full blood count, thyroid function tests, creatine kinase, urine myoglobin, vitamin B12 and folic acid levels.

Potassium level was 1.7 mEq/L (normal 3.5-5.5), and all other parameters were within normal ranges.

The ECG showed inverted T waves and the presence of U waves. An Example of an ECG:

Hypokalemic periodic paralysis is a rare disorder that may be hereditary as the primary cause, or secondary due to thyroid disease, strenuous physical activity, a carbohydrate-rich meal and toxins. The patients are mostly of Asian origin.

The most common presentation is of symmetrical weakness in lower limbs, with a low potassium level and ECG changes of hypokalemia. The patients may have a history of similar weaknesses which may be several years old. An attack may be triggered by infections, stress, exercise and other stress-related factors.

The word ‘weakness’, can lead to physicians thinking about stroke, neurological deficits and other life-threatening illnesses such as spinal cord injuries associated with high morbidity and mortality which need to be ruled out in the ED.

In this case, history and examination are vital. Weakness in other parts of the body, a thorough neurological examination are important aspects.

Patients are monitored and treated with potassium supplements (oral/Intravenous) until the levels normalize. ECG monitoring is essential, as cardiac function may be affected. 

The patient should be examined to assess the strength and should be referred for further evaluation and to confirm the diagnosis.

The differential diagnosis for weakness in lower limb include :

  1. Spinal cord disease (https://iem-student.org/spine-injuries/)
  2. Guillain barre syndrome
  3. Toxic myositis
  4. Trauma
  5. Neuropathy
  6. Spinal cord tumour

References

Cite this article as: Sumaiya Hafiz, UAE, "Hypokalemic Periodic Paralysis in the ED," in International Emergency Medicine Education Project, September 7, 2020, https://iem-student.org/2020/09/07/hypokalemic-periodic-paralysis-in-the-ed/, date accessed: September 24, 2021

Question Of The Day #11

question of the day
qod 11

Which of the following is the most appropriate next step in management for this patient’s condition?

IV antihypertensives and CT surgery consultation (Choice A) would be the best treatment for a patient with aortic dissection. This diagnosis is characterized by severe tearing chest pain that radiates to the back, along with hypertension. Risk factors include tobacco smoking, uncontrolled hypertension, trauma (i.e. rapid deceleration), and connective tissue diseases (i.e. Marfan syndrome). Other than chest pain with radiation to the back, this patient lacks the other risk factors for aortic dissection, making Choice A less likely. IV heparin (Choice B) would be the correct choice for the treatment of pulmonary embolism and acute coronary syndrome (i.e. NSTEMI). Both of these diagnoses are possible, but a chest CT scan with PO water-soluble contrast is not the gold standard for diagnosing PE or ACS. A CT Pulmonary angiogram is ideal for PE diagnosis, and an EKG along with troponin levels are ideal for ACS diagnosis. Pericardiocentesis (Choice C) is the treatment for cardiac tamponade. The patient’s vitals show no evidence of obstructive shock, and there is no history of penetrating chest trauma, pericardial effusion, end-stage renal disease, HIV, lupus, cancer, or other risk factors for cardiac tamponade. Choice D outlines the best course of action to take in a patient with esophageal rupture, which is the disease described in the question stem. This condition can occur spontaneously after forceful vomiting causing high pressures in the esophagus (Boerhaave syndrome). In this situation, the chest pain typically begins after the onset of vomiting. Other etiologies of esophageal rupture include deceleration injuries and penetrating trauma (i.e. gunshot wounds, iatrogenic via esophagogastroduodenoscopy (EGD)). A “Hamman’s Crunch”, subcutaneous emphysema, fever, and signs of shock can be seen on exam. Diagnosis is confirmed by an esophagram or a CT scan of the chest with water-soluble oral contrast (i.e. Gastrograffin). Esophageal rupture is a life-threatening diagnosis as esophageal contents can spill into the mediastinum, causing mediastinitis and septic shock. The treatment is typically surgical with the repair of the perforated segment and drainage of fluid collections. Correct Answer: D  

References

Smith LM, Mahler SA. Chest Pain. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill; Accessed August 17, 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219641169

Nickson, C. (2019) Oesophageal Perforation. Life in the Fast Lane. Accessed August 17, 2020. https://litfl.com/oesophageal-perforation/

Cite this article as: Joseph Ciano, USA, "Question Of The Day #11," in International Emergency Medicine Education Project, September 4, 2020, https://iem-student.org/2020/09/04/question-of-the-day-11/, date accessed: September 24, 2021

Question Of The Day #10

question of the day
qod10 palpitation

Which of the following is the most appropriate next step in management for this patient’s condition?

This patient has a narrow-complex tachycardia with a regular rhythm. A narrow QRS complex is defined as a QRS interval less than 120msec. This is a normal finding. The differential diagnoses for regular narrow complex tachycardia include sinus tachycardia, atrial tachycardia, atrial flutter, and supraventricular tachycardia (“SVT”). SVTs are typically associated with narrow QRS complexes, unless there is a concurrent bundle branch block, other aberrant conduction, or the existence of electrical accessory pathways as in Wolff Parkinson White (WPW) syndrome. The heart rate of an SVT can vary from 140-280 beats/min. Intravenous Adenosine (Choice A) is a hallmark of SVT treatment, however, Adenosine is given after vagal maneuvers have been attempted and have failed. Synchronized cardioversion (Choice B) is a last-ditch effort treatment in a patient with SVT. Vagal maneuvers and medications are attempted prior to using cardioversion. However, if the patient is hypotensive, cardioversion should be employed. Intravenous Amiodarone (Choice C), beta-blockers, calcium channel blockers, or other antiarrhythmics can be used to terminate SVTs if vagal maneuvers and adenosine are not effective. Vagal maneuvers (Choice D), such as the Valsalva maneuver (“bearing down”) or carotid massage, are the initial treatment for SVTs. Correct Answer: D 

References

Burns, E. (2019, March 30). Supraventricular Tachycardia (SVT). Life in the Fast Lane. https://litfl.com/supraventricular-tachycardia-svt-ecg-library/

Nickson, C. (2019, March 24). Narrow Complex Tachycardia. Life in the Fast Lane. https://litfl.com/narrow-complex-tachycardia/

Cite this article as: Joseph Ciano, USA, "Question Of The Day #10," in International Emergency Medicine Education Project, August 28, 2020, https://iem-student.org/2020/08/28/question-of-the-day-10/, date accessed: September 24, 2021

A case of decreasing resistance in ER

a case decreasing resistance in er

I keep games on the 4th home screen of my cell phone. The third screen is blank. A minuscule of energy required to swipe my thumb has prevented me one too many times from mindlessly launching an RPG. Only to realize 2 hours later I had other plans for those 2 hours. An American comedian, the late Mitch Hedberg famously joked once,

Mitch Hedberg (1968-2005)
Mitch Hedberg (1968-2005)

I have always believed that the subtle truths kneaded so artfully in seemingly light, small-talk-worthy jokes are what makes a comedian a genius. How many times have you thought that you need to pick up that particular grocery or fill up that one conference form only to instead get consumed by what was easily available?

Our mind is built so that it follows the path of least resistance no matter how insignificant the resistance is. Although smudged all over the canvas of self-help, non-fiction genre, medicine somehow isn’t used frequently to exemplify the path of least resistance.

Today, I present to you a case that inspired us at Beltar, to remove one such small resistance from our workflow. The implications as you will see were no less than life-saving.

Rural Health System : Oversimplified

Before I present to you the case, a small preamble: Health care in rural Nepal is still run mostly by paramedics. No matter what spectrum you fall in terms of appreciating their work, the fact remains that they are the major workforce we have at the rural. It suffices to say that they are the portal of entry to the health system of our country for many. All emergency cases, once screened and declared complicated, the medical officer (usually a MBBS doctor) at the PHC sees the patient. Majority of cases are seen only by paramedics – considering 3 to 5 paramedics, usually and barely one medical officer in most PHCs.

A mobile game I wouldn't play

Now that the characters are in place, let’s dive right into the no less than a fairy tale land of the rural health system. Lamenting about the obvious lack of resources has been so old school that I don’t even make a typo while typing about it these days. We had one ECG machine at Beltar. The old ECG machine with its squeaky sound and myriad varieties of artifacts stood with all its mighty bulk inside a locked door of a room. The key protected from no one in particular by the office assistant who would open the door, drag the machine out, bring it to the bedside. The paramedic who decided to do the ECG would then untangle the wire glazed with what little of gel we had applied to the previous patient. He would then connect the limb leads and the pre-cordial leads with the trusty suction knobs which hopefully has some gel left from the previous use and then comes the biggest connection to be made: connecting the machine to the power grid. “Don’t you keep your machine charged!?”, you ask. We do. But the Li-ion battery probably has undergone autophagy, or whatever fancy name the process is given. That is a lot of steps and by extension, a lot of resistance. If this were a mobile game, I don’t think I would be addicted to it.

A Race Against Time

A patient with diabetes who had visited our ER a couple of times before was being monitored for chest pain at around 7 AM on a Saturday morning. I was washing my clothes on the first floor unaware that my Saturday is not going to be about laundry and daily chores. When I was called to check the patient, she was already deteriorating at a rate far greater than our PHC could ever catch up. We tried to borrow the speed of an ambulance and refer the patient to a higher center. An ST elevation in any two contiguous lead is an MI. Our paramedics knew that. To everybody’s surprise, ECG was not done! Given the fact that we did not have cardiac enzymes available at the PHC and Aspirin was all we could have prescribed before discharge anyway: we gave the patient 2 Aspirin tablets to chew and referred her as fast as we could. My paramedic colleagues have demonstrated utmost clinical competence and professionalism too many times to doubt any of that. The work environment was still error-prone and the circumstance demanded a change. Could we have changed the outcome given the same resources and clinical scenario? Maybe we need to decrease the resistance I thought. Changing how we store ECG (shown in the picture below), making it more accessible not only increased the frequency with which it was being used but also served as a reminder. A physical question hanging down the IV stand asking anyone who is attending a case, “Do you need to use me?”

ECG machine in plain sight with IV stand holding the limb and pre-cordial leads for accessibility

Workarounds: Because Solutions are Late to the Party.

If you have been following my writings, you’d have noticed this as another small tweak, a workaround, a nudge to the existing system so to speak that isn’t the substitute for the actual sustainable solution. Robust training that helps hard-working paramedics conceptualize and understand the protocols related to the use of basic yet life-saving diagnostics like ECG can be a start. We tried printing and pasting some protocols on the walls; another workaround we hope would help make patient care better until it actually sustainably improves. Another workaround that a friend suggested was: everyone who aches above the waist, gets an ECG. Such simplification works well to decrease the resistance in learning complex protocols. I am sure there are plenty of workarounds used worldwide, a necessity, after all, is the mother of invention. I leave you with a thought: What effect do you think will a systematic sharing of such workarounds among the rural healthcare workers will produce?

Guides to ECG electrode placement and protocols
Cite this article as: Carmina Shrestha, Nepal, "A case of decreasing resistance in ER," in International Emergency Medicine Education Project, February 21, 2020, https://iem-student.org/2020/02/21/a-case-of-decreasing-resistance-in-er/, date accessed: September 24, 2021

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Deadly ECG Patterns – 5 Can’t Miss ECG Findings

5 Can’t Miss ECG findings

An average ER physician performs around 100 tasks in an hour and gets interrupted at least every 6 minutes. One of the common interruptions in the ED is a request to “sign off” on an ECG of a patient who has been triaged but not seen by a doctor yet. Therefore, knowing deadly ECG patterns is an essential skill for emergency physicians, residents, as well as medical students who rotate in the emergency department.

Below are five ECG patterns that should raise concerns for red flag conditions.

ECG #1

A 37-years-old female patient presented to the ED with complains of dizziness and generalized fatigue. She was started on ACE inhibitors few months ago and missed her clinic appointments. Her bedside VBG revealed a K+ of 8.1

ECG source - Dr. Smith's ECG blog

The ECG shows severe bradycardia, wide QRS complexes and symmetrically peaked T waves in V2-V5.

Key Take Home Points

Hyperkalemia can present with multiple abnormalities on an ECG, including

  • Tall, peaked T waves with a narrow base (best seen in precordial leads)
  • Progressive flattening and eventually disappearance of P waves
  • Wide QRS complexes
  • Bradyarrhythmias (sinus bradycardia, slow AF, second and third-degree AV blocks)
  • Sine wave appearance (pre-terminal rhythm)
  • Endgame: Ventricular fibrillation

Always consider the diagnosis of hyperkalemia in a patient with a history of dialysis, renal failure, or treatment with drugs like ACE inhibitors, ARBs, spironolactone especially if the ECG shows bradycardia or complete heart block.

ECG #2

A 56-years-old patient presented to the ED with lightheadedness and dizziness. Initial vitals showed hypotension and tachycardia.

ECG source - Dr. Smith's ECG blog
ECG source - Dr. Smith's ECG blog

The above ECG shows low voltage, lectrical alternans: the beat-by-beat R-wave amplitude changes best appreciated in the precordial leads. A bedside ECHO completed after the initial ECG showed a large pericardial effusion.

Key Take Home Points

Massive pericardial effusion can produce a triad of:

  • Low QRS voltage
  • Tachycardia
  • Electrical alternans (consecutive, normally-conducted QRS complexes alternate in height)

Consider the possibility of pericardial effusion and a potential impending cardiac tamponade in patients with electrical alternans on ECG.

ECG #3

A 65-years-old patient was brought to the ED by family members in a disoriented state. Further history revealed that the patient was taking digoxin as one of his regular medications. His serum digoxin level was 2.7 ng/ml.

ECG Source - learntheheart.com
ECG Source - learntheheart.com

The above rhythm strip shows atrial tachycardia with 2:1 AV block.

Key Take Home Points

Always have a high suspicion of digoxin toxicity in a patient taking digoxin presenting with the disoriented state.

Digoxin toxicity can cause a wide variety of arrhythmias. It is classically associated with supraventricular tachycardias but a slow ventricular response (e.g.: atrial tachycardia with high-grade AV block).

The other common rhythms include:

  • Regularized atrial fibrillation (AF with complete heart block + accelerated junctional escape rhythm which produces a paradoxically regular rhythm)
  • Bidirectional VT (polymorphic VT with QRS complexes alternating between LBBB and RBBB morphology)

Digoxin toxicity should be separated from the normal digoxin effect that can occur in patients taking the expected dose of digoxin. The digoxin effect (image below) includes sagging ST-segment depression, abnormal T waves (flat, inverted or biphasic) and a short QT.

ECG source - Dr. Smith's ECG blog

ECG #4

A 45-years-old patient presented to the ED with a history of severe central chest pain lasting about 10 – 15 minutes. Cardiac enzymes were negative. However, with the above ECG findings, the patient was sent to the Cath lab and subsequent coronary angiography revealed proximal LAD artery occlusion.

By Jer5150 - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=19598089

The above ECG shows deep T wave inversions in precordial leads. This is known as the Wellen’s sign.

Key Take Home Points

Wellens syndrome is a pattern of deeply inverted or biphasic T waves in V2-V3 which is highly specific for critical stenosis of left anterior descending (LAD) artery.

There are two patterns of T wave abnormality in Wellens syndrome

  • Type A: Biphasic T waves (initially positive and terminally negative)
  • Type B: Deep and symmetrically inverted (Most common type)

Note that patients can be completely pain-free with normal cardiac enzyme levels. Patients are, however, at extremely high risk of anterior wall MI due to the critical LAD stenosis and need appropriate Cardiology consultation and management urgently.

ECG #5

A 17-years-old previously healthy male patient who had one attack of syncope earlier in the day presented to the ED.

ECG Source - Peter Allely - liftl.com
ECG Source - Peter Allely - liftl.com

The ECG pattern is diagnostic of Brugada syndrome – coved shaped ST-elevation > 2mm followed by an inverted T wave seen in V1 and V2.

Key Take Home Points

Such finding is very serious in a patient with a recent episode of unconsciousness.

The suspicion of Brugada syndrome must be confirmed or excluded by an urgent consultation with a cardiologist.

Conclusion

ECGs in isolation are usually not enough to make a diagnosis – always correlate with clinical history and/or confirmatory investigations.

Try looking at as many ECGs as possible to improve your skills of pattern recognition and picking up subtle changes in ECGs.

Cite this article as: Neha Hudlikar, UAE, "Deadly ECG Patterns – 5 Can’t Miss ECG Findings," in International Emergency Medicine Education Project, November 22, 2019, https://iem-student.org/2019/11/22/deadly-ecg-patterns-5-cant-miss-ecg-findings/, date accessed: September 24, 2021

Cardiac Monitoring Pearls

Cardiac Monitoring chapter written by Stacey Chamberlain from USA is just uploaded to the Website!