Raised ICP is associated with certain characteristic ECG changes:
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”).
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.
Example 1 – SAH
- Widespread, giant T-wave inversions (“cerebral T waves”) secondary to subarachnoid haemorrhage.
- The QT interval is also grossly prolonged (600 ms).
Example 2 – SAH
- Another example of cerebral T-waves with marked QT prolongation secondary to subarachnoid haemorrhage.
Example 3 – SAH
- 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).
Amal Mattu presents a case of intracranial haemorrhage with characteristic ECG findings.
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- Mattu A, Brady W. ECGs for the Emergency Physician 2, BMJ Books 2008.
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice (6th edition), Saunders 2008.
- Wagner, GS. Marriott’s Practical Electrocardiography (11th edition), Lippincott Williams & Wilkins 2007.