How does cyanide affect heart function?

Cyanide primarily affects the body by interfering with its ability to use oxygen, which has significant implications for heart function. When cyanide is present, it inhibits cytochrome c oxidase, an essential enzyme in the electron transport chain of mitochondria. This inhibition prevents cells from utilizing oxygen effectively, leading to cellular hypoxia even when there is sufficient oxygen supply in the bloodstream.

As the heart muscle relies heavily on aerobic respiration to generate the energy needed for contractions, the inability to use oxygen can severely disrupt its normal function. The heart may become less effective at pumping blood, which can result in cardiovascular collapse and potentially lead to respiratory failure as the body struggles to deliver oxygen to vital organs. Therefore, the critical role of oxygen in maintaining heart rhythm and function explains why cyanide exposure can ultimately lead to respiratory failure due to inadequate aerobic metabolism affecting the entire body.