**Question:** A 50 year old man develops an excruciating headache. On examination he has nuchal rigidity. NCCT performed after 4 hours shows blood in the Sylvian fissure. What does the ECG show?

**Core Concept:**
The provided scenario describes a patient with a subarachnoid haemorrhage (SAH), a type of stroke caused by bleeding into the subarachnoid space around the brain. Nuchal rigidity is a sign of increased intracranial tension and is often seen in SAH. NCCT (non-contrast computed tomography) is a common diagnostic imaging technique used to identify SAH. The blood in the Sylvian fissure refers to a specific location within the brain where the fissure is present, which is the Sylvian fissure, named after the French anatomist, Jean-Baptiste de la Harpe Sylvius.

**Why the Correct Answer is Right:**
The correct answer, D, refers to the electrocardiogram (ECG). In a patient with SAH, there is a 50% risk of cardiac arrhythmias, particularly the development of atrial tachycardia (atrial fibrillation or atrial flutter) due to the hypercoagulable state caused by the hemorrhage in the brain. The hypercoagulable state leads to increased platelet aggregation and clot formation, which can result in cardiac arrhythmias.

**Why Each Wrong Option is Incorrect:**
A. An ECG does not directly show the presence of blood in the brain, specifically in the Sylvian fissure, as it is concerned with cardiac function and rhythm.

B. Similarly, an ECG does not typically reveal signs of increased intracranial pressure or intracranial hemorrhage, making it an incorrect choice.

C. Cardiac complications in patients with SAH are less common, making it a less likely option compared to option D.

**Clinical Pearl:**
In patients with SAH or any neurological insult, it is essential to monitor for both cardiac and neurological complications. While ECGs may not directly demonstrate intracranial hemorrhage or increased intracranial pressure, they can reveal cardiac arrhythmias linked to the hypercoagulable state caused by the hemorrhage in the brain. This highlights the importance of comprehensive patient assessment and management, considering both neurological and cardiovascular aspects of patient care.