Abstract

ACUTE STROKE AND HIGH BLOOD PRESSURE

‘High’ blood pressure (BP) is defined by the World Health Organization as systolic BP > 140 mmHg and diastolic BP > 90 mmHg. High BP is common in both acute ischaemic and haemorrhagic stroke, affecting about 80% of the patients, and this reflects several mechanisms (International Society of Hypertension Writing Group 2003):

• pre-existing hypertension;

• the stress of hospitalization;

• raised intracranial pressure (Cushing reflex);

• activation of neuro-endocrine pathways (sympathetic nervous system, mineralocorticoid and glucocorticoid).

The BP normally falls over the first week after stroke but it can fluctuate considerably making it difficult to discern trends in individuals. The relationship between BP and outcome is ‘U-shaped’ with both high and low BP being associated independently with death or dependency (Fig. 1) (Leonardi-Bee et al. 2002). This link between high BP and a poor outcome appears to be related to be related to