PEARLS:

Myocarditis is a diagnosis of exclusion that should be considered in a relatively healthy person who presents with a cardiopulmonary complaint with cardiomegaly, heart failure, unexplained tachycardia, low grade fever and recent URI.

EKG changes in young people are often difficult to interpret, but remember, reciprocal changes are never benign.

There are many causes of chest pain, but the 6 Killers must be considered and ruled out before going down any other diagnostic pathway in all patients who present with chest pain.

CASE: A 21 yo otherwise healthy male presents to the Urgent Care with 2 hours of chest pain, worse with deep breathing. He is currently being treated with azithromycin for a sore throat and URI by his PMD. The pain radiates to the right shoulder, not to the back, and is worse with deep breathing and exertion. He describes the pain as both sharp and pressure-like and it is associated with a productive cough.





PMHx:

Father had an MI at 45 years old.

No smoking, alcohol or other drug use.

Physical Exam:

VS: afebrile, HR 80, RR 16 BP 118/76

Lungs are clear, heart is regular without murmur, abdomen is soft and non-tender.

The patient is PERC negative.

EKG shows ST changes in the inferior and lateral distribution and an inverted T wave in III.

DISCUSSION:

It is important to think about EKG changes in the context of the patient’s history. Aspects of this patient’s history that are more concerning are:

Radiation of pain to the right shoulder - chest pain that radiates in any direction, but particularly to the right side should raise your concern for ACS

Pain is worse with exertion

Father with MI at a young age

EKGs in young people often look different from EKGs in older people. Early depolarization is a common finding.

Early repolarization is common in young men and is typically seen as j-point elevation in the right precordial leads V2 & V3, and sometimes in the inferior and lateral leads.

If these changes are seen and the patient is a young man, this is reassuring.



ST segments should be concave upward (like a cup holding water). If they are straight, or convex upward (like a tombstone), this is not early repolarization.



Early repolarization should not be associated with any reciprocal change. There should be no ST depression.



Exceptions are aVR and V1 where ST depression can be present and normal. Any ST depression in any of the the other 10 leads, cannot be called early repolarization. A flipped T-wave is not a reciprocal change.



Additional tips:



Look at an old EKG. If the ST elevation has been there before, this is re-assuring.





If you don’t have an old EKG, obtain serial EKGs, about every hour. If the patient has active ischemia, there is a good chance that there will be evolving changes. If there are no changes at all over time, this is reassuring as well.

Remember the anatomic distribution of EKG leads:

Inferior MIs: ST elevation in II, III, aVF. You will most commonly will see ST depression or downsloping of the initial part of the T wave in aVL. aVL is the most common lead in which you see reciprocal changes when a person is having an inferior wall STEMI.

An isolated flipped T wave or an isolated Q wave in III or aVF is ok, but you can’t have the flipped T wave or Q wave in both those leads.



“A flipped T is free in III.”





Lateral leads are V5, V6, I and aVL. A lateral MI will show with ST changes and/or flipped T waves in these leads. You may see reciprocal changes in the inferior leads.





Anterior leads are V3 and V4.





Septal leads are V1 and V2.





Posterior MIs are the most commonly missed MI and the most common MI associated with delayed time to the cath lab or to lytics.





Remember, posterior MIs occur at the back of the heart and the EKG leads are placed on the front of the chest so you are going to see the opposite findings. A posterior STEMI is going to show as ST depression in V1-V4. Whenever you see ST depression in V1-V4, you always have to worry about a posterior STEMI. Repeat the EKG with 2 leads on the patients left-mid back. If these 2 leads so ST elevation, you have a posterior STEMI.







Sometimes people will flip the EKG over and hold it up to the light to look at it backwards or look at the EKG in a mirror, but this doesn’t answer the important question.







The question with ST depression in V1, V2, V3 is: is this a posterior STEMI and they need to go immediately to the cath lab or get lytics, or is this anterior wall ischemia and are ok way ASA, heparin and admission to the CCU with plan for cath in a day or two. There is a big difference between anterior ischemia vs. posterior STEMI.







From the Urgent Care, the question is: am I calling the ED and telling them to activate the cath lab as I transfer the patient emergently with lights and sirens, or simply transferring the via ALS in the usual manner?

CASE CONTINUES:

The patient is transported to the ED via ambulance. En route he receives aspirin and nitroglycerin. On arrival at the ED a repeat EKG shows some ST elevations in V4-V6, without any reciprocal changes or T wave inversions. A cardiac work up is initiated with the provider leaning towards a diagnosis of pericarditis or PE over MI, until the patient’s troponin comes back at 14 (high normal = 0.08).

The patient is admitted to the hospital and undergoes an echocardiogram that shows a globally decreased ejection fraction of 40-45% with apical hypokinesis concerning for myocarditis vs. Takotsubo Cardiomyopathy.

Differential Diagnosis: The 6 Killers.

You must consider these every time a patient reports chest pain.

Acute coronary syndrome

Viral cardiomyopathy or myocarditis/pericarditis/endocarditis

Pulmonary embolism

Aortic dissection

Esophageal rupture

Tension pneumothorax

Takotsubo Cardiomyopathy

A stress or emotion-induced cardiomyopathy first diagnosed in Japan in 1990.

Can present as a STEMI-mimic or with other non-specific EKG changes and elevated troponin.

The echocardiogram shows classic findings of apical hypokinesis.

More common in women in their 40s and 50s.

Viral Myocarditis

A very difficult diagnosis to make that must be a diagnosis of exclusion.

Seen in sick patients with a cardiopulmonary complaint in whom you do not expect to have underlying heart problems. Typically young, healthy people with a preceding viral infection.

Patients present with ACS symptoms, abnormal EKG, troponin elevation, heart failure symptoms and often an enlarged heart on CXR.

Pericarditis on EKG: a diagnosis of exclusion - particularly must exclude ACS

Diffuse ST elevations with depressions allowed in V1 or aVR. No other leads can have depressions.

No reciprocal changes.

All ST elevations are concave upwards. If the ST elevations are flat or convex, it is not pericarditis, it is a STEMI.

Ideally, PR depression in many leads. Only viral pericarditis gives you PR depressions. Other causes of pericarditis do not cause PR depressions.

CASE CONCLUSION:

After admission to the hospital and thorough cardiac evaluation, the patient was diagnosed with a viral myocarditis (remember, the patient has been taking azithromycin for a URI).

Viral Myocarditis can be a very difficult diagnosis to manage, because there is no specific therapy. It can be deadly and even very sick patients can only be managed with supportive care.

Think myocarditis in a relatively healthy person if you see: