According to a study published in the journal Science Advances, female and male hearts respond differently to the stress hormone called noradrenaline. The body′s "fight or flight" response is mediated by the neurotransmitter and hormone noradrenaline. The findings, according to the study′s authors, may have implications for how different sexes respond to medicine and for human cardiac problems, including arrhythmias and heart failure.

For the study, the scientists created a brand-new kind of fluorescence imaging apparatus that allowed them to utilise light to see in real-time how the subject’s heart reacts to hormones and neurotransmitters. When the subjects received norepinephrine injections, the researchers saw that the female heart′s electrical activity varied depending on which parts of the heart returned to normal more rapidly than the male heart.

The author of the study explained that the differences in electrical activity that the research team observed in the female hearts are called repolarization. Repolarization refers to how the heart resets between each heartbeat and is closely linked to some types of arrhythmias. 

(Source: https://www.daijiworld.com/news/newsDisplay?newsID=1042444 )