Contraindications and uncertainty
Some findings should change the conversation entirely.
Cardiac disease, a history suggesting rhythm instability, and concurrent medicines known to prolong the QT interval deserve particular caution. QT prolongation refers to a change in cardiac electrical timing that can be associated with dangerous arrhythmias; the Long QT syndrome reference offers a plain starting point for understanding the concept, but interpretation belongs with qualified medical professionals.
Psychiatric screening also matters. A history of psychosis, mania, severe dissociation, acute suicidality, or destabilization with psychoactive substances may change the risk picture. Substance use, sleep loss, trauma, and medication changes can complicate that assessment. Screening should make space for uncertainty rather than compressing it into a simple yes or no.
“Informed consent is meaningful only when it includes the possibility that screening may identify a reason not to proceed.”