Wed10November0747AM 3

A 56-year-old lady presents with sudden onset occipital headache, vomiting and depressed conscious level. She was previously well with no significant past medical history. In particular there is no history of exertional chest pain, asthma or diabetes. She is a non-smoker.

Examination reveals neck stiffness, equal pupils and a GCS of 12. Pulse is 84 bpm, BP 140/90 mmHg. Chest is clear to auscultation. Laboratory findings are normal. An urgent CT brain scan reveals an acute subarachnoid haemorrhage and she is transferred to neurosurgery.

After conducting further investigations the neurosurgery team plan to take her to theatre for clipping of an aneurysm. The anaesthetic team are concerned about her ECG shown below.

What is the most likely explanation from the list of options?

(Please select 1 option)

Left bundle branch block

Acute myocardial infarction

Ventricular pre-excitation This is the correct answer

Pulmonary embolism

ECG changes due to intracranial haemorrhage Incorrect answer selected

Explanation

The ECG shows a shortened PR interval (in this case the PR interval is approximately 0.08 s - two small squares NR 0.12-0.2 s) and a delta wave. In this case it is probably best seen in the lateral chest leads V3 - V6.

Ventricular pre-excitation (if there were a history of tachycardia it would be Wolff-Parkinson-White syndrome) commonly masquerades as other conditions, such as bundle branch block or ischaemia.

Intracranial haemorrhage can cause changes in the ECG which are typically deep symmetrical T-wave inversion and prolonged QT interval.

Acute pulmonary embolism is unlikely, as there are none of the transient features that one would expect to see (S1Q3T3 pattern, RV strain and tachycardia).

Answer Statistics

1

1%

2

7%

3

12%

4

1%

5

81%

Times answered: 332