I've been watching some classic horror movies as of late, and a trope I see in many of them is where a person will see the big bad monster and "die of fright." I'm curious, for the average person, could this happen? Or would it require a prior medical condition of some kind?
The people whom this happens to consider themselves average people.
The thought is that catecholamine surge caused by the event triggers some predisposition to cardiac arrhythmia - maybe inherited, maybe due to medicines. People predisposed to this sort of arrhythmia probably do not know that is the case, and consider themselves to be average people. It would seem that the victims of this are not average and have some sort of predisposition to that problem. There is a lot of interest in figuring out who there people are in advance - not in the context of being frightening to death but in the context of SUDEP - sudden death in epilepsy. Epileptic people sometimes just die, presumably for cardiac reasons, but there is no way of knowing who among this large group is at risk.
In the following abstract the frightening thing is being restrained. Other circumstances that produce a catecholamine surge can do it too.
Med Sci Law. 2016 Apr;56(2):85-90. doi: 10.1177/0025802414568483. Epub 2015 Jan 26. Sudden cardiac death with stress and restraint: The association with sudden adult death syndrome, cardiomyopathy and coronary artery disease.
Krexi L1, Georgiou R2, Krexi D1, Sheppard MN3. Author information Abstract OBJECTIVE: The aim of this study was to report on sudden cardiac death (SCD) during or immediately after a stressful event in a predominately young cohort. METHODS: This study used retrospective non-case-controlled analysis. A total of 110 cases of SCD in relation to a stressful event such as altercation (45%), physical restraint (31%) in police custody (10%), exams/school/job stress (7.27%), receiving bad news (4%), or a car accident without injuries (2.73%) were retrospectively investigated. The majority of the subjects experiencing SCD were male (80.91%). The mean age was 36 ± 16 years (range 5-82 years). Twenty-three cases (20.91%) were psychiatric patients on antipsychotic medication. RESULTS: Fifty-three per cent of cases died with a negative autopsy and a morphologically normal heart, indicating sudden adult death which is linked to cardiac channelopathies predisposing to stress-induced SCD. Cardiomyopathy was found in 16 (14.5%) patients and coronary artery pathology in 19 (17%) patients, with atherosclerosis predominating in older patients. CONCLUSIONS: This study highlights SCD during psychological stress, mostly in young males where the sudden death occurred in the absence of structural heart disease. This may reflect the proarrhythmic potential of high catecholamines on the structurally normal heart in those genetically predisposed because of cardiac channelopathy. Structural cardiomyopathies and coronary artery disease also feature prominently. Cases of SCD associated with altercation and restraint receive mass media attention especially when police/other governmental bodies are involved. This study highlights the rare but important risk of SCD associated with psychological stress and restraint in morphologically normal hearts and the importance of an expert cardiac opinion where prolonged criminal investigations and medico-legal issues often ensue.