Can heart palpitations cause fainting?

No: Heart palpitations is a symptom. As a general rule, causes of fainting (i.e. Loss of consciousness) are not symptoms.

Yes: Dependent on the cause of palpitations, if the person is having very fast cardiac arrhythmias, he/she can very well pass out (faint). The fast heart rate or the type of arrhythmia can cause a low cardiac output state leading to low blood pressure and the resulting fainting episode.

Yes: ? If heart palpitations can cause fainting. The medical condition Postural Orthostatic Tachycardia Syndrome (POTS) has associated rapid heart beat & fainting symptoms. This is an autonomic nervous system mediated disorder; sometimes associated with Joint Hypermobility Syndrome (see Brighton criteria) &/or chronic pain. People with POTS often have lightheadeedness upon standing up too fast.