ECG Pointers: Intracranial Hemorrhage

Author: Lloyd Tannenbaum, MD (Emergency Medicine Resident, San Antonio, TX) // Edited by:  Jamie Santistevan, MD (@jamie_rae_EMdoc – EM Physician, Presbyterian Hospital, Albuquerque, NM); Manpreet Singh, MD (@MPrizzleER – Assistant Professor of Emergency Medicine / Department of Emergency Medicine – Harbor-UCLA Medical Center); and Brit Long, MD (@long_brit  – EM Attending Physician, San Antonio, TX)

Welcome to this edition of ECG Pointers, an emDOCs series designed to give you high yield tips about ECGs to keep your interpretation skills sharp. For a deeper dive on ECGs, we will include links to other great ECG FOAMed!


The Case:

You get a call from EMS that they are bringing in a 72-year-old alcoholic male who was found down by his family. His initial trauma evaluation is unremarkable, but when you take him to the CT scanner, you find an intraparenchymal hemorrhage. There are currently no beds in the ICU, so you have to board him in your ED for a few hours until one of the beds will be freed up. It’s a busy shift, and you keep trying to move through patients. About 2 hours later, one of your nurses comes to tell you that your patient is becoming more and more hypertensive and bradycardic. His heart rate has been as low as 30.  She hands you this ECG:

This ECG shows sinus rhythm with a rate of 47. There is a single P-wave before each QRS, making a heart block or ventricular rhythm unlikely. 

You review his vitals over the past 2 hours and see that his heart rate on admission was in the 80s and has now dropped to the 30s, while his blood pressure was initially 110/54 and has now skyrocketed to 187/125! What could be going on?

This patient’s presentation is very concerning for Cushing’s triad, which is a sign of impending brain herniation. Cushing’s Triad (first described by neurosurgeon, Dr. Harvey Cushing) is:

  • Hypertension
  • Bradycardia
  • Irregular Respirations

Why do we see these symptoms in patients with increased intracranial pressure?

High intracranial pressure (ICP) is life-threatening. It causes a decrease to the cerebral blood flow (CBF) leading to an increase in carbon dioxide (CO2). This triggers a sympathetic response making the body think that the brain is not getting enough blood. It tells the rest of the body to clamp down (vasoconstriction) to send more blood to the brain. This is symbolized as increasing the mean arterial pressure (MAP) in an attempt to increase the cerebral perfusion pressure (CPP). The baroreceptors in the aortic arch and carotid arteries see the increased blood pressure and try to tell the heart to chill out, leading to bradycardia, but the brain is still under strain. This becomes a vicious cycle of the brain trying to get more blood and the baroreceptors trying to equilibrate, so you see hypertension and bradycardia.

What other ECG changes can you see in a patient with increased intracranial pressure?

Well, almost anything! A recent review article by Takeuchi et. al. published in the Journal of Clinical Neuroscience found that ECG changes are extremely common. They looked at ECGs obtained within 24 hours for 118 patients with an intracranial hemorrhage and found that 66 patients (56%) had ECG changes. The changes they found were: [1]

  • ST depression (24%)
  • Left ventricular hypertrophy (20%)
  • Corrected QT interval (QTc) prolongation (19%)
  • T-wave inversion (19%).

Such changes are thought to be neurogenically mediated and can mimic cardiac ischemia or infarct. There are case reports of patients presenting to the hospital with out of hospital cardiac arrest, and once ROSC is obtained, they have an ECG consistent with STEMI. The cath lab gets activated, and the patient is found to have clean coronaries but then later is diagnosed with an intracranial bleed [2,3]. These patients can also have elevated troponin, further confounding the diagnosis.

What are “Cerebral” T-Waves?

“Cerebral” T-waves are deep, symmetric, inverted T-waves seen on an ECG in patients with large intracranial bleeds. The exact mechanism of a head bleed causing ECG changes is currently unknown. Dr. Levis recently published a great example of cerebral T waves in the Permanente Journal in 2017 [4]:

Note the deep, symmetric, and inverted T-waves, especially noticeable in V3-V6. These are consistent with “Cerebral” T-waves.

Life in the Fast Lane has a bunch of interesting examples of ECG changes from patients with intracranial hemorrhages, especially “Cerebral” T-waves. You can see those at: https://lifeinthefastlane.com/ecg-library/raised-intracranial-pressure/

Case conclusions:

Our patient was taken to the CT scanner and found to have a large intracranial hemorrhage with several millimeters of midline shift. He was taken emergently to the OR for decompression.

Take home points:

  • In patients with intracranial hemorrhage, hypertension and bradycardia can be signs that herniation is occurring.
  • There are many nonspecific ECG changes seen in patients with intracranial hemorrhage including ST changes, QT prolongation, and T-wave inversions.
  • Occasionally these changes can mimic acute coronary syndromes including STEMI and can lead to misdiagnosis, unnecessary thrombolytics, or PCI.
  • Sometimes, it isn’t the heart…

Want more FOAM?

LIFTL presents a great case of ECG findings with elevated ICP.

Dr. Smith also provides some great examples on Dr. Smith’s ECG Blog.

References:

  1. Takeuchi, S. Nagatani, K. Otani, N. Wada, K. and Mori, K. Electrocardiograph abnormalities in intracerebral hemorrhage. Journal of Clinical Neuroscience. 2015. 15(22). 1959-1962.
  2. Lewandowski, P. Subarachnoid haemorrhage imitating acute coronary syndrome as a cause of out-of-hospital cardiac arrest – case report. Anaesthesiology Intensive Therapy. 2014. 46(4). 289-292.
  3. Al-Zaiti, S. Crago, E. Hravnak, M. Kozik, T. Pelter, M, and Carey, M. ECG Changes During Neurological Injury. American Journal of Critical Care. 2015. 24 (5). 253-254.
  4. Levis, J. ECG Diagnosis: Deep T Wave Inversions Associated with Intracranial Hemorrhage. The Permanente Journal. 2017; 21.

Leave a Reply

Your email address will not be published. Required fields are marked *