1. Atrial Fibrillation Slideshow Pictures
2. Atrial Fibrillation (A-Fib) Quiz: Test Your Medical IQ
3. Heart Symptoms Never to Ignore Slideshow

Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Daniel Lee Kulick, MD, FACC, FSCAI

Daniel Lee Kulick, MD, FACC, FSCAI

Dr. Kulick received his undergraduate and medical degrees from the University of Southern California, School of Medicine. He performed his residency in internal medicine at the Harbor-University of California Los Angeles Medical Center and a fellowship in the section of cardiology at the Los Angeles County-University of Southern California Medical Center. He is board certified in Internal Medicine and Cardiology.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• How does the heart work?
• Premature atrial contractions (PACs) and premature ventricular contractions (PVCs)
• Sinus tachycardia
• Sinus bradycardia
• Abnormal heart rhythms
• Tachycardia
• Ventricular fibrillation
• Ventricular flutter
• Paroxysmal supraventricular tachycardia (PSVT)
• Wolf-Parkinson-White Syndrome
• Atrial fibrillation
• Atrial Flutter
• Bradycardia
• Heart blocks
• When should I seek medical care?
• How are heart rhythm disorders diagnosed?
• What is the treatment for heart rhythm disorders?
• Can heart rhythm disorders be prevented?
• Atrial Fibrillation Slideshow Pictures
• Take the Atrial Fibrillation Quiz
• Heart Symptoms Never to Ignore Slideshow
• Patient Comments: Abnormal Heart Rhythms - Treatments
• Patient Comments: Heart Rhythm Disorders - Type of Disorder
• Find a local Cardiologist in your town
• Heart Rhythm Disorders Index

Paroxysmal supraventricular tachycardia (PSVT) occurs when the pathways in the AV node or atrium allow an altered conduction of electricity, and the atrium begins firing in a fast but regular rate, sometimes more than 150 -200 times per minute. The ventricle, sensing the electrical activity coming through the AV node, tries to beat along with each electrical impulse and PSVT occurs.

This is rarely a life threatening event, but most people feel uncomfortable when PSVT occurs. They may become lightheaded, weak, have shortness of breath, and describe a feeling of fullness in the throat. PSVT is usually tolerated and can even stop on its own. If this is a first time event, activating EMS (emergency medical services) and calling 911 is important, since other tachycardias can be life threatening.

The treatment for PSVT include attempts to stimulate the vagus nerve to slow the heart (see vasovagal syncope above) by holding one's breath and bearing down as if to have a bowel movement. Intravenous medications are often used to interrupt the episode. Many patients have PSVT due to congenital abnormalities in the electrical conduction system of the heart. External causes can include hyperthyroidism, electrolyte imbalances, and the use of caffeine, alcohol, over-the-counter cold medications containing stimulants, or illegal drugs like cocaine and methamphetamine.

Wolfe-Parkinson-White syndrome is a specific type of PSVT, in which an inborn error of wiring has occurred near the AV node, and an accessory electrical pathway exists. The diagnosis is made by electrocardiogram (EKG), and the treatment may include medication control to prevent recurrent tachycardias or catheter mediated ablation (destruction) of the abnormal pathway.