Would these treatments help my tachychardia and anxiety?

I'm looking into alternative treatments for these, specifically chiropractic care and acupuncture. Could these possibly help?

Both of those treatments can remedy your situation. I place more trust in the acupuncture over the chiropractic treatments but if you're able to, I see no reason why you shouldn't look into both of them. They are both highly therapeutic.

NO! YOU NEED TO SEE A CARDIOLOGIST! Seriously!!!

Cardiologists (medical experts in heart care) have specialized training in the diagnosis and treatment of heart rhythm disorders. Diagnosis often includes electrophysiologic testing for potentially serious tachycardia. The decision for medical treatment, and the method selected, can be made only after a comprehensive diagnosis. Treatment for tachycardia has two main types: medications and nonsurgical procedures (catheter radiofrequency ablation). A pacemaker may also be used. For patients with ventricular tachycardia, another treatment option is an implanted defibrillator. Chiropractic care and accupuncture will have no effect on your heart's muscle or electrical activity.

Alternative health care should never be the only treatment for serious conditions.
However, chiropractic, acupuncture, other alternative practices, and nutritional supplements can all provide additional support and treatment along with professional medical care.

But not all alternative therapies are appropriate in all situations, and you should consult your doctor and your alternative care practitioner to determine the best combination for you.

First of all I would definetly go to a Dr. and make sure it's nothing serious. Papitations are generally not and can be coming from alot of different things. Anxiety, hormonal issues(in women), thyroid problems, poor nutrition, nicotine and caffeine, prescription medications, adrenal disorders. A Dr. can rule out anything serious and if it needs medical attention.
If it's just a general anxiety disorder there are several supplements and herbs that are quite helpful. I would also suggest meditation and yoga. Just 20 min of each every day can and will reduce the symptoms of anxiety greatly.