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BradyCardia by Brady Pregerson, MD
​​​NEW BRADIA PHOTO FOR BLOG.JPGThis blog covers a new ECG topic every month with emphasis on interesting tracings and lessons that will change or improve your practice of emergency medicine.​

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Wednesday, May 1, 2019

A 42-year-old man presented to the ED with palpitations and constant nonpleuritic, nonexertional, nonradiating chest pain that started about two hours before, shortly after he snorted meth. He reported no shortness of breath, sweating, syncope, near-syncope, or other complaints. He said this had never happened before and he was quitting meth.

The patient's vital signs were normal except for a mild tachycardia between 100 and 115 bpm. His exam was otherwise normal, and his teeth and skin were in good condition. The initial differential diagnosis included tachydysrhythmia, acute coronary syndrome, and anxiety, and his initial ECG is shown below.

bradycardia-meth ecg.jpg

The computer read was junctional tachycardia at a rate of 104 bpm. Do you agree?

The computer interpretation is likely incorrect because the ECG most likely shows ectopic atrial tachycardia. Note the unusual P-axis with down-going P waves in the inferior leads. The computer was likely reading junctional tachycardia because there is a regular narrow tachycardia that is too slow to be SVT and it didn't recognize the P-waves at all.

It is possible, though much less likely, that the rhythm is actually junctional tachycardia with a prolonged PR interval. No concerning ST or T wave changes suggest ischemia.

Blood work showed his potassium a bit low at 3.1 mEq/L and negative serial troponins. The patient was given Ativan and potassium chloride. After about an hour and a half, his repeat ECG showed normal sinus rhythm, and he was discharged home. Find more information on junctional tachycardia and atrial ectopic tachycardia in the highlighted areas of the image below.

(This ECG was peer-reviewed by Stephen W. Smith, MD, of Dr. Smith's ECG Blog.)

bradycardia-tachycardia handout.jpg

Source: The Emergency Medicine 1-Minute Consult Pocketbook.

Monday, April 1, 2019

A 72-year-old man with a history of ventricular tachycardia (VT) after the placement of an automatic implantable cardioverter-defibrillator presented to the ED with intermittent heartburn for two weeks. He noted no correlation with activity or meals. The episodes usually lasted five to 45 minutes. He reported no other complaints.

The patient's vital signs were normal except for a pulse in the range of 110-130 bpm. He was also tachycardic and had mild peripheral edema. The initial differential diagnosis included primary tachycardia, acute coronary syndrome, pulmonary embolism, and GERD. His initial ECG looked like this:

bradycardia-VT corrected.jpg

ECG Analysis

The ECG showed many features that make this certain to be VT. He had an ICD, which implies a low ejection fraction, and all patients with defibrillators are at risk for VT. Standard VT (not fascicular VT) initiates in pathologic myocardium and slowly propagates until it reaches the conducting fibers, making the first part of the QRS slow.

That is what we see in the ECG. In leads II and V5 across the bottom, the onset of the QRS to its peak is approximately 120 ms. This is extremely slow. In lead aVR, the onset of the QRS consists of a Q-wave that is wide and of low voltage (one of Verekei's VT criteria). Time from onset of R to the nadir of the S-wave in RS complexes is more than 100 ms (one of Brugada's VT criteria). Here it is extremely long, about 180 ms.

There is also RBBB morphology (upright QRS in lead V1) with the first R peak greater in amplitude than that of the second R peak (another of Brugada's VT criteria). This is a sign of VT, as opposed to another pre-existing tachycardia.

The patient remained stable. His baseline ECG showed a different QRS morphology, so this was not sinus tachycardia with baseline bundle branch block. His AICD was interrogated, and he was determined to be in ventricular tachycardia with rates that never reached his defibrillator threshold, which was set to trigger at rates above 130. He was admitted to the CCU for observation, and his AICD settings were adjusted.

(This ECG was peer-reviewed by Stephen W. Smith, MD, of Dr. Smith's ECG Blog.)

bradycardia-VT 2.jpg

Source: The Emergency Medicine 1-Minute Consult Pocketbook.

Friday, March 1, 2019

A 72-year-old man presented to the ED with five days of dry cough and generalized abdominal bloating and three days of constipation. He said he had not experienced fever, shortness of breath, chest pain, rectal pressure, or vomiting. He had a small bowel movement on the day of his presentation but felt no better, so he decided not to wait until his upcoming appointment with his primary care physician.

Vital signs were normal except for a pulse of 115 bpm. Physical exam was normal except for tachycardia. His lungs were clear, and his abdomen was benign. His differential diagnosis included constipation, gallstones, and viral upper respiratory infection.

His CBC and BMP were normal, but his liver function tests were slightly elevated. Chest x-ray showed an enlarged cardiac silhouette and a small pleural effusion on the right. His ECG is shown below. The computer ECG read showed sinus tachycardia, nonspecific ST changes, and prolonged QT interval. Do you agree?

bradycardia-pericardial effusion tamponade.jpg

The computer read appeared to be correct, but there was also low voltage. These findings and the chest x-ray results were new, so a large pericardial effusion was suspected.

Abdominal ultrasound showed small ascites but no gallstones or masses. Bedside echo showed a large pericardial effusion and findings suspicious for early tamponade. A formal echo confirmed tamponade, and the patient was taken to the cath lab for emergent pericardiocentesis, where 1 L of sanguineous fluid was removed. No definite cause was found.

It was unclear if the constipation and bloating were incidental to the pericardial tamponade or just represented atypical symptoms, but they were likely the former. Certainly, cough may occur with tamponade, but the typical symptoms are dyspnea and generalized weakness. Other variable symptoms include syncope, near-syncope, palpitations, and chest pain. Tachycardia and JVD are the most common exam findings. Tachycardia and low voltage, especially when new, are the most common ECG findings. Electrical alternans is far less common, but is more specific for tamponade than low voltage or tachycardia.

See the yellow highlighted area below for additional information on tamponade.

bradycardia-pericardial effusion tamponade 2.jpg

Source: The Emergency Medicine 1-Minute Consult Pocketbook.

Friday, February 1, 2019

A 72-year-old man with end-stage COPD presented to the ED with dyspnea on exertion and pleuritic, nonexertional chest pain. He stated that he always had shortness of breath, but it had been getting worse over the past three days. He said he had no fever, cough, leg swelling, or other complaints. He also had no history of pulmonary embolism or coronary artery disease, and said whenever his shortness of breath worsened, it had always been because of his COPD. He stated that this time it felt different from anything he had ever experienced before, primarily because of the pain.

His vital signs were normal, except for a blood pressure of 78/55 mm Hg. Of note, the patient was very thin. His physical exam was also normal, except for moderate labored breathing and wheezing. Our initial differential diagnosis included acute coronary syndrome, pulmonary embolism, pericarditis, COPD, and pneumonia.

The patient's initial ECG showed a normal sinus rhythm with premature atrial contractions and nonspecific ST and T-wave changes.


The ECG also showed diffuse ST segment elevation and mild PR segment depression. It also revealed a premature atrial contraction, which were non-specific changes. They could represent acute coronary syndrome, but they were more consistent with pericarditis.

Cardiology saw the patient and felt he had pericarditis. His blood pressure rapidly improved with fluids (and the use of an appropriately smaller blood pressure cuff helped). Lactic acid and serial troponins were normal, but his D-dimer was elevated. Chest CT and echocardiogram showed a small pleural effusion but no pericardial effusion or PE. He was treated for COPD and pericarditis and did well.


Source: The Emergency Medicine 1-Minute Consult: Quick Essentials Pocketbook, 5th Edition

Monday, December 31, 2018

A 77-year-old man presented to the ED for sudden onset of painless dyspnea 20 minutes earlier. He did not report chest discomfort, nausea, palpitations, lightheadedness, or any other complaints.

His vital signs are normal except for a pulse of 131 bpm. You astutely notice that his blood pressure is soft at 101/83 mm Hg. His exam is otherwise normal except for bilateral mottling of the skin in the legs more than the arms.

His initial differential diagnosis included tachydysrhythmia, pulmonary embolism, and acute coronary syndrome.

His ECG is shown. What does it demonstrate?

bradycardia-submassive PE1.jpg

The ECG shows sinus tachycardia with nonspecific T and ST changes. ACS is possible, but given the lack of pain and tachycardia, submassive PE should top your differential. See the highlighted area below for a one-minute consult.

Major take-home points for PE are that large PEs are frequently painless (because they do not cause lung infarcts), tachycardia is rarely present except in large PEs, and ECG changes can be nonspecific.

bradycardia-submassive PE2.jpg

Source: The Emergency Medicine 1-Minute Consult Pocketbook.