Raised Intracranial Pressure

Characteristic ECG Abnormalities with Raised Intracranial Pressure

Other possible ECG changes that may be seen:

• ST segment elevation / depression — this may mimic myocardial ischaemia or pericarditis
• Increased U wave amplitude
• Other rhythm disturbances: sinus tachycardia, junctional rhythms, premature ventricular contractions, atrial fibrillation

In some cases, these ECG abnormalities may be associated with echocardiographic evidence of regional ventricular wall motion abnormality (so-called “neurogenic stunned myocardium”).

Causes

ECG changes due to raised ICP are most commonly seen with massive intracranial haemorrhage:

• Subarachnoid haemorrhage
• Intraparenchymal haemorrhage (haemorrhagic stroke)

They may also be seen with:

• Massive ischaemic stroke causing cerebral oedema (e.g. MCA occlusion)
• Traumatic brain injury
• Cerebral metastases (rarely)

In one case series, the ECG pattern of cerebral T-waves with prolonged QT interval was seen in 72% of patients with SAH and 57% of patients with intraparenchymal haemorrhage. 

ECG Examples

Example 1

Subarachnoid Haemorrhage

• Widespread, giant T-wave inversions (“cerebral T waves”) secondary to subarachnoid haemorrhage
• The QT interval is also grossly prolonged (600 ms)

Example 2

Subarachnoid Haemorrhage

• Another example of cerebral T-waves with marked QT prolongation secondary to subarachnoid haemorrhage

Example 3

Subarachnoid Haemorrhage

• Widespread T-wave inversions with slight ST depression secondary to subarachnoid haemorrhage
• The QT interval is prolonged (greater than half the R-R interval)
• This ECG pattern could easily be mistaken for myocardial ischaemia as the T-wave morphology is very similar, although obviously the clinical picture would be very different (coma versus chest pain)

Example 4

Traumatic Brain Injury

• This ECG was taken from a previously healthy 18-year old girl with severe traumatic brain injury and massively raised intracranial pressure (30-40 mmHg)
• There is widespread ST elevation with a pericarditis-like morphology and no reciprocal change (except in aVR and V1)
• She had no cardiac injury / abnormality to explain the ST elevation
• The ST segments normalised as the intracranial pressure came under control (following treatment with thiopentone and hypertonic saline)

Related Topics

• CCC — Subarachnoid Haemorrhage: Overview
• CCC — Subarachnoid Haemorrhage: ICU Management
• CCC — Monitoring in Subarachnoid Haemorrhage
• CCC — Subarachnoid Haemorrhage Grading Systems
• CCC — Vasospasm in Subarachnoid Haemorrhage
• CCC — Subarachnoid Haemorrhage: Initial Management
• CCC — Subarachnoid Haemorrhage: Prognostication
• CCC — Subarachnoid Haemorrhage: Complications

References

• Jachuck, SJ. Electrocardiographic abnormalities associated with raised intracranial pressure. Br Med J. 1975 Feb 1; 1(5952): 242–244. PMC 1672050
• Gregory, T. Cardiovascular complications of brain injury. Contin Educ Anaesth Crit Care Pain (2012) 12 (2): 67-71. doi: 10.1093/bjaceaccp/mkr058

Advanced Reading

Online

• Wiesbauer F, Kühn P. ECG Mastery: Yellow Belt online course. Understand ECG basics. Medmastery
• Wiesbauer F, Kühn P. ECG Mastery: Blue Belt online course: Become an ECG expert. Medmastery
• Kühn P, Houghton A. ECG Mastery: Black Belt Workshop. Advanced ECG interpretation. Medmastery
• Rawshani A. Clinical ECG Interpretation ECG Waves
• Smith SW. Dr Smith’s ECG blog.
• Wiesbauer F. Little Black Book of ECG Secrets. Medmastery PDF

Textbooks

• Zimmerman FH. ECG Core Curriculum. 2023
• Mattu A, Berberian J, Brady WJ. Emergency ECGs: Case-Based Review and Interpretations, 2022
• Straus DG, Schocken DD. Marriott’s Practical Electrocardiography 13e, 2021
• Brady WJ, Lipinski MJ et al. Electrocardiogram in Clinical Medicine. 1e, 2020
• Mattu A, Tabas JA, Brady WJ. Electrocardiography in Emergency, Acute, and Critical Care. 2e, 2019
• Hampton J, Adlam D. The ECG Made Practical 7e, 2019
• Kühn P, Lang C, Wiesbauer F. ECG Mastery: The Simplest Way to Learn the ECG. 2015
• Grauer K. ECG Pocket Brain (Expanded) 6e, 2014
• Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric 6e, 2008
• Chan TC. ECG in Emergency Medicine and Acute Care 1e, 2004

LITFL Further Reading

• ECG Library Basics – Waves, Intervals, Segments and Clinical Interpretation
• ECG A to Z by diagnosis – ECG interpretation in clinical context
• ECG Exigency and Cardiovascular Curveball – ECG Clinical Cases
• 100 ECG Quiz – Self-assessment tool for examination practice
• ECG Reference SITES and BOOKS – the best of the rest