Tachycardia, can it cause passing out!?

My mom has this problem of passing out from time to time. She has hit her head a few times. Her doctor just told her she has tachycardia. She has also been undergoing chemotherapy for Ovarian Cancer for the past
1 1/2 years. Is there any connections between these problems, and what can she do about the passing out??

Of course it can. When you have a supraventricular tachycardia episode, your heart rate increases dramatically. Normal functioning is around 60-100 bpm, while affected by SVT, your heart rate is much higher, around 150-200 bpm (Beats Per Minute). That is not the only symptom though, here are many more:
A racing or fluttering feeling in the chest (palpitations).
Chest discomfort (pressure, tightness, pain).
Lightheadedness or dizziness.
Fainting (syncope).
Shortness of breath.
A pounding pulse. You may feel or see your pulse beating, especially at your neck, where large blood vessels are close to the skin.
Sweating.
Tightness or fullness in the throat.
Tiredness (fatigue).
Excessive urine production.

I couldnt really tell you if her heart condition is closely realted to the ovarian cancer treatment but I do know that certain conditions that were created due to this treatment have been know to cause tachycardia: Overly high levels of the heart medication digoxin (such as Lanoxicaps or Lanoxin) or the bronchodilator theophylline (such as Bronkodyl, Elixophyllin, Slo-Bid, Slo-Phyllin, or Theo-Dur). Other serious health problems, such as chronic obstructive pulmonary disease, heart failure, pneumonia, or metabolic problems can all cause or lead to SVT.

Just make sure she studies this disease and realizes what she needs to stay away from to help curd these episode. Such as overuse of caffeine, nicotine, or alcohol or use of illegal drugs, such as cocaine or methamphetamine.

Decongestants that contain stimulants should also be avoided, including oxymetazoline (such as Afrin and other brands) and pseudoephedrine (such as Sudafed, Actifed, and other brands). Doctors also warn against using nonprescription diet pills or "pep" pills, because many contain caffeine, ephedra (recently banned), ephedrine, the herb ma huang, or other stimulants.

Also a good piece of advice for you is to find out exactly what type of Tachycardia she has. There is a type of Supraventricular Tachycardia called Wolff-Parkinson-White syndrome, this is simply when an abnormal electrical connection (or bypass tract) between the atria and ventricles of the heart, of which Wolff-Parkinson-White (WPW) is the most common. The bypass tract allows electricity in the heart to travel abnormally fast and results in a very rapid heart rate. This condition has been shown to be genetic, meaning it can be passed down to offspring. SO both you and your mother be very careful in your diets and pphyscial activity. Either one can be potentially very dangerous.

tachycardia is a heart rate over 100 beats a minute.that's all i know