ECG Abnormalities with Raised Intracranial Pressure
- Widespread giant T-wave inversions (“cerebral T waves”).
- QT prolongation.
- Bradycardia (the Cushing reflex – indicates imminent brainstem herniation).
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”)
- 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.
- Widespread, giant T-wave inversions (“cerebral T waves”) secondary to subarachnoid haemorrhage.
- The QT interval is also grossly prolonged (600 ms).
- Another example of cerebral T-waves with marked QT prolongation secondary to 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).
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).
- Brady WJ, Truwit JD. Critical Decisions in Emergency and Acute Care Electrocardiography
- Hampton, JR. The ECG In Practice, 6e
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric, 6e
- Wagner, GS. Marriott’s Practical Electrocardiography 12e
- Chan, TC. ECG in Emergency Medicine and Acute Care
- Mattu, A. ECG’s for the Emergency Physician
LITFL Further Reading
- ECG BASICS — Waves, Intervals, Segments and Clinical Interpretation
- ECG A to Z by diagnosis –alphabetical diagnostic approach to the ECG
- ECG CLINICAL CASES — ECG’s placed in clinical context with a challenging Q&A approach
- 100 ECG Quiz — Self-assessment tool for examination practice
- ECG Reference SITES and BOOKS — the best of the rest
- LITFL ECG IMAGE Database — Searchable database of LITFL ECG’s
- ECG and Cardiology Eponymous Syndromes — Cheats guide to eponymous emancipation
- ECG Exam Template — a framework for answering ECG exam questions.