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  4. Case 4: Stroke symptoms

Case 4: Stroke symptoms

An 80 year old man presents with sudden onset of one sided weakness of his face and slurred speech. He lives with his similarly aged wife in deprived neighbourhood. He has been on treatment with a thiazide and calcium channel blocker for hypertension. He was normally fit and well.
How does heat make people more likely to die directly and through its effects on the cardiovascular system?

Mammals respond to heat by vasodilation of the vessels, if there is prolonged significant vasodilation then the heart has to work harder to maintain blood flow around the body. This leads to an increased risk of heart attacks and strokes. This is a direct effect of heat, dehydration and renal impairment will be additional factors. 

 

Will his drugs have made this more or less likely?

Diuretics will add to the dehydration and Calcium channel blockers will increase the vasodilation, both exacerbating stress on the heart. There is currently (2024) little established advice in UK or internationally on drug holidays and heat though there is some guidance here. 

Off guidance possibilities might include patients taking their own blood pressure during hot spells and reducing specified BP treatments if the blood pressure is low. 

Is living in a deprived neighbourhood relevant to the stroke (and if so how?)

Deprived neighbourhoods are associated with much higher levels of air pollution and most UK (and European) cities have significantly higher air pollution than WHO guidelines. Air pollution is linked to higher risks of many diseases from cardiovascular disease to diabetes and dementia. 

Air pollution will act as an irritant triggering more asthma or rhinitis but small particulate matter (PM2.5) will become intracellular and this changes cell behaviour triggering a wider spread of diseases.

Air pollution will build up in cars (unless using specialist filters) so that the average levels of pollution exposure are higher for a commute by car than for the same journey by bike or walking. 

 Do you normally consider planetary health when you see somebody with a cardiovascular disease or stroke in hot weather?

Heat and it’s impacts are still not widely talked about in the consulting room. Clinicians are all taught to ask about tobacco use (which accounts for 8 million deaths every year) and alcohol (3 million every year) but air pollution is estimated to contribute to 6.7 million deaths per year 5.7 of these due to non communicable disease.

NB the UK death rate attributed to the cold is 13400 (12.21 to 3.22) compared to the spring and autumn periods.  Heat related deaths are significantly lower at 4,500 for 2022