Cool County Cases - Myo My! A Curious Case of Chest Pain in the ED

The Case:

The patient is a 30-year-old female with no past medical history who presented with a complaint of chest pain that began 1 hour prior to arrival. She stated that the chest pain was on the left side, and it radiated all the way down her left arm and made her fingertips feel numb. She described the pain as a “heaviness.” The pain was accompanied by dyspnea on exertion. She denied nausea, vomiting, diaphoresis, fevers, and recent illness. She had no family history of cardiac disease. She denied all PE risk factors. She denied smoking, alcohol, and drug use.

Triage Vitals: Temp 36.3 C, BP 121/77 mmHg, HR 50 bpm, RR 19 bpm, O2 Sat 98% on RA

Triage Point-of-Care ED Troponin: 0.027 ng/mL (Ref Range: 0.000 – 0.028)

Triage EKG:

Figure 2. Index EKG from triage.

Interpretation: Sinus rhythm. Q waves in I, AVL. ST depressions in V2-V3. No comparison was available.

On physical examination: The patient was uncomfortable appearing and appeared dyspneic. No murmurs are appreciated. Lungs clear to auscultation bilaterally.

Initial Questions:

What was the differential at this time based on the information available?

- Acute coronary syndrome (ACS), Pneumonia, Costochondritis, Spontaneous Coronary Artery Dissection (SCAD)

What ancillary studies were ordered for this patient?

- CBC, BMP, VBG, Troponin, CXR

What was the initial medical decision-making process?

- Due to the concerning chest pain story and the initial troponin being drawn within an hour of symptom onset, the plan was to repeat the troponin and EKG. ACS vs SCAD remained high on the differential.

ED Course:

The patient had the above troponin result within normal limits prior to evaluation by a resident physician. A bedside echo was performed and was without regional wall motion abnormality, effusion, or abnormality of gross ejection fraction. A repeat 2-hour troponin resulted at 0.208 ng/mL, cardiology was consulted, and the patient was given aspirin and sublingual nitroglycerin (Figure 1). The patient was admitted to the CCU for monitoring and serial cardiac biomarkers.

Brief Hospital Course:

- The patient was admitted to CCU and started on heparin and nitroglycerin drip.

- Cardiac catheterization is completed the next day and demonstrates no abnormalities. Heparin drip is discontinued.

- A cardiac MRI is completed, and the image is interpreted as having findings consistent with Myopericarditis.

Diagnosis: Myopericarditis

Management:

- Suggested diagnostic evaluation and management for cardiologists is primarily based on expert opinion (1) given the lack of clear clinical guidelines and large clinical trials. A clinical diagnosis of myocarditis should be deferred to cardiologists, and decisions on management and disposition should be made in conjunction with a cardiologist. 

- In a case where direct cardiology consultation is unavailable or pending, treatment should be supportive, with the emergency physician addressing complications, controlling pain, and stabilizing vital signs (2, 3).

- Potential complications include acute decompensated heart failure and arrhythmias.

- Stable heart failure should be managed with diuresis. Further management may include initiating ACE inhibitors, beta-blockers plus mineralocorticoid receptor agonists, or immunosuppressive therapy, but this should be deferred to a consulting cardiologist.

- Unstable heart failure should be managed supportively with vasopressors followed by mechanical cardiopulmonary support (e.g., ECMO or LVAD placement); thus, when transferring, consider identifying ECMO-capable facilities.

- Patients should be monitored on telemetry to evaluate for arrhythmias. Supraventricular tachycardias in patients without severe heart failure can be managed with beta-blockers or calcium-channel blockers cautiously. When rhythm control is necessary, options include amiodarone and dofetilide, but other class I and class III antiarrhythmics should be avoided.

- Pain should be managed with acetaminophen and opioid analgesics. NSAIDs should be avoided as current data suggests NSAIDs may conversely enhance the underlying inflammatory processes (2). Medications like nitroglycerin have little role in these patients since this is not a vascular process.

- Discharge can be appropriate, but should be done after cardiology consultation. No specific intervention is recommended for outpatient management, but patients should be counseled to avoid exercise, NSAIDs, and alcohol (2).

Learning points:

1) Serial troponin improves sensitivity and specificity for acute myocardial infarction (AMI) of any variety (4). Our case displays the importance of serial troponins, given an initially normal troponin was observed in the case of a patient experiencing an AMI.

2) Myopericarditis is a difficult diagnosis due to the broad presentation and laboratory testing often being nonspecific. Suspected causes are broadly infectious vs. inflammatory vs. toxic agent exposure (5). Currently, cardiac biopsy remains the gold standard of diagnosis, but cardiac MRI  is becoming a promising non-invasive diagnostic tool (1, 2).

3) EKG changes are nonspecific in myocarditis, but an abnormal EKG is present in approximately 85% of cases (1). Patients have been found to have nonspecific T-wave inversions, ST elevations or depressions, QRS prolongation, AV blocks, symptomatic bradycardia, or ventricular dysrhythmias.

4) Patients with this diagnosis require follow-up with cardiology, given a percentage of patients may still have sequelae of cardiac damage (i.e., dilated cardiomyopathy) despite a lack of underlying coronary artery disease (1, 4).

Authored by Niyi Soetan, MD and Jessica Folk, MD

References: 

1. Ammirati E, Frigerio M, Adler ED, Basso C, Birnie DH, Brambatti M, Friedrich MG, Klingel K, Lehtonen J, Moslehi JJ, Pedrotti P, Rimoldi OE, Schultheiss HP, Tschöpe C, Cooper LT Jr, Camici PG. Management of Acute Myocarditis and Chronic Inflammatory Cardiomyopathy: An Expert Consensus Document. Circ Heart Fail. 2020 Nov;13(11):e007405. doi: 10.1161/CIRCHEARTFAILURE.120.007405. Epub 2020 Nov 12. PMID: 33176455; PMCID: PMC7673642.

2. Editors. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e. McGraw Hill; 2016. Accessed October 02, 2023. 

3. Cooper LT. Treatment and prognosis of myocarditis in adults. UpToDate. August 11, 2022. Accessed October 2, 2023. https://www.uptodate.com/contents/treatment-and-prognosis-of-myocarditis-in-adults?search=myocarditis+treatment&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1#H550304593.

4. Wassie M, Lee M, Sun BC, et al. Single vs Serial Measurements of Cardiac Troponin Level in the Evaluation of Patients in the Emergency Department With Suspected Acute Myocardial Infarction. JAMA Netw Open. 2021;4(2):e2037930. doi:10.1001/jamanetworkopen.2020.37930

5. Chew DP, Briffa TG, Alhammad NJ, Horsfall M, Zhou J, Lou PW, Coates P, Scott I, Brieger D, Quinn SJ, French J. High sensitivity-troponin elevation secondary to non-coronary diagnoses and death and recurrent myocardial infarction: An examination against criteria of causality. Eur Heart J Acute Cardiovasc Care. 2015 Oct;4(5):419-28. doi: 10.1177/2048872614564083. Epub 2014 Dec 11. PMID: 25505224.

6. Dec GW Jr, Waldman H, Southern J, Fallon JT, Hutter AM Jr, Palacios I. Viral myocarditis mimicking acute myocardial infarction. J Am Coll Cardiol. 1992 Jul;20(1):85-9. doi: 10.1016/0735-1097(92)90141-9. PMID: 1607543.