The Cardiovascular System in Heat Stroke

Area of Science:

• Environmental Health
• Cardiology
• Thermoregulation

Background:

• Extreme heat waves, like the one in western Canada in June 2021, cause record-breaking temperatures.
• Heat waves lead to increased mortality, emergency visits, and hospitalizations, primarily due to cardiovascular events.
• The human body dissipates heat via sweating and increased skin blood flow, which are impaired in individuals with cardiovascular disease.

Purpose of the Study:

• To review the complex interplay between the cardiovascular system and heat stroke.
• To elucidate the pathophysiology of heat stroke in relation to cardiovascular function.
• To outline the cardiovascular complications and treatment strategies for heat stroke.

Main Methods:

• Literature review of existing research on heat stroke and cardiovascular physiology.
• Analysis of heat wave impacts on public health, focusing on mortality and morbidity.
• Synthesis of current knowledge on thermoregulation and cardiovascular responses to thermal stress.

Main Results:

• Heat dissipation mechanisms rely on a functional cardiovascular system to increase skin blood flow and cardiac output.
• Impaired cardiovascular function limits the body's ability to cope with heat, increasing heat stroke risk.
• Cardiovascular complications, including arrhythmias, ischemia, heart failure, shock, and sudden death, are common in heat stroke patients.
• The majority of excess deaths during heat waves are cardiovascular in origin.

Conclusions:

• The cardiovascular system is critically involved in both the development and complications of heat stroke.
• Individuals with pre-existing cardiovascular conditions face a heightened risk of severe heat stroke and associated mortality.
• Understanding this interaction is crucial for developing effective prevention and treatment strategies for heat stroke during extreme heat events.