This case study reports on changes in emotions before and during an unexpected heart rate in a young, apparently healthy male with a life-long history of exercise in the absence of family history of heart problems. He completed the Brunel Mood Scale (Terry et al. , 2003) to assess emotions before, during, and after the heart attack, and also describing his thoughts during these periods. Results indicate he experienced unpleasant emotions in the build up to the heart attack, feelings he attributed at the time to frustration to achieve fitness goals. He maintained an exercise regime prior to having a heart attack, a finding consistent with previous research suggesting that early diagnosis, although vital for survival, is not likely to be identified among seemingly healthy individuals. During the heart attack, he experienced a rapid emotional change characterised by a rapid increase in anger coupled with thoughts of needing to survive. The intensity of emotions and regulation strategies employed before and during the heart attack provide insight this experience, and we suggest future research should investigate emotional change during adverse conditions.