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Bradycardia: Assume cardiac cause until proven guilty: Emergency Medicine News

ECG, GERD, retrosternal burn, catheterization:

Image 1. The patient’s first ECG taken during triage.

Figure
Figure

A man in his mid-fifties with no medical history presented to hospital with about an hour of retrosternal burn that improved but did not resolve after taking famotidine. The pain had started while he was lying down after eating pizza, but it was worse and lasted longer than his usual heartburn.

He did not have nausea or shortness of breath, but he did get sweaty and started coughing after the pain started. He had said it was difficult to breathe deeply. He was overweight and couldn’t remember the last time he saw a doctor. He said he does not smoke and has no syncope, palpitations, chest pain, fever, or other symptoms.

The patient’s vital signs were normal, as was his exam. His triage ECG about an hour after the onset of symptoms is displayed. (Image 1.) The computer read it as normal sinus rhythm, low voltage, borderline ECG. The ECG was repeated once he was in a room, about two hours after the onset of heartburn. (Image 2.) The computer reading was the same.

What should you do next? Try Maalox or nitroglycerin, order a D-dimer in addition to the usual labs, or none of these?

ECG analysis

The first ECG shows low blood pressure, possibly due to bodily habit as the pulse is low and he does not smoke, making tamponade and COPD unlikely. A suspicion of ST segment depression is observed in leads 1, II, and aVL, and a subtle ST segment elevation may be present in V1-V2, but this could easily be a normal variant.

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Figure:

Image 2. Patient’s second ECG taken approximately two hours after the onset of heartburn.

The second ECG shows dynamic changes with increased ST elevation in V1-V2 that the computer does not call, but the change in shape and size of T waves in V2-V6 is more impressive. These are hyperacute T waves: the upward slope went from concave to the right (this is the sign “bam” or “check mark”, according to Amal Mattu, MD). The overall volume of these T waves has increased, and they are quite large relative to their QRS; you can even integrate the entire QRS into the T-wave.

Stephen W. Smith, MD, of Dr. Smith’s ECG Blog, pointed out that even the first ECG, while less of a concern than the second, is perfect for applying the four-variable formula to differentiate normal ST segment elevation from a subtle left anterior descending coronary artery occlusion myocardial infarction. The formula gives a value of 22.0, which is very specific for LAD OMI. This could bring the patient to the cath lab even earlier and lead to a better result. The formula is on MDcalc, and a free iPhone app called Subtle STEMI and a free Android app called ECG Smith can calculate the index.

Maalox should generally only be tried once you are fairly sure it is not an ACS; otherwise it could mislead you. It wastes time in this case. You can certainly try nitroglycerin if the patient has no contraindications, but it is more important to activate the cath lab or at least send an anonymized copy of the ECG to the cardiologist. You really shouldn’t be doing anything that delays your visit to the cath lab, so don’t order D-dimer. Mid-sternal burn is unlikely to be PE, although it is somewhat pleuritic. A positive D-dimer can also lead you astray. Time is muscle here.

The correct answer in this case is to do none of the above. This patient’s history and repeated ECG should prompt you to activate the cath lab or call cardiology as soon as possible. Human troponin-i was less than 0.03 (99% URL

Case lesson

Patients with MI often say they have no pain and just feel pressure, burning, or discomfort. Don’t let them convince you that their pain is not cardiac; only you should do it! Always perform a repeat ECG early in patients with persistent chest symptoms if the first ECG was taken within three hours of symptom onset.

This post has been peer reviewed by Stephen W. Smith, MD, of Dr. Smith’s ECG Blog (https://bit.ly/306xAeq).

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Dr Pregersonis an emergency physician with Palomar Health in San Diego. He is the author of Emergency Medicine 1 Minute Consultation, 8 in 1 Emergency Service Quick Reference Guide, A-to-Z Emergency Pharmacopoeia & Antibiotics Guide, Don’t Try This At Home, and Think Twice: More lessons from RE. Follow him on twitter@ EM1MinuteGuru, and visit their website athttps://em1minuteconsult.com. Read his past columns onhttp://bit.ly/BradyCardiaEMN.