by McCoy K
Tachycardia
(Ventricular Tachycardia; Supraventricular Tachycardia; Paroxysmal Atrial Tachycardia)
Definition
Tachycardia is a rapid heart rate of more than 100 beats per minute. Sinus tachycardia, from the heart's sinus node, is a normal response to exercise, illness, or stress.
There are several types of abnormal tachycardias or
arrhythmias
. These can come from two places:
- Atria (the two smaller chambers on the top of the heart)—called
supraventricular tachycardias
- Ventricles (the lower chambers of the heart)—called
ventricular tachycardia
This condition can be life-threatening. But, it can be treated. If you think you or someone you know has this condition, get emergency help.
Causes
This condition is caused by abnormal electrical impulses that control the heart.
Risk Factors
These factors increase your chance of having tachycardia. Tell your doctor if you have any of the following:
-
Heart disease, especially a prior
heart attack
- Cardiomyopathy
—damage to the muscle wall of the lower chambers of the heart
- Electrolyte abnormalities—too much or too little calcium, sodium, magnesium, and potassium in the blood
- Myocardial ischemia—insufficient blood flow to heart muscle tissue
- Hypoxemia—not enough oxygen in the blood
- Acidosis—too much acid in the body’s fluids
Symptoms
If you have any of these symptoms do not assume it is due to this condition. These symptoms may be caused by other conditions. Tell your doctor if you have any of these:
- Heart palpitations
- Fast heart rate
- Dizziness
- Lightheadedness
- Fainting or near fainting
- Chest pain
- Shortness of breath
Diagnosis
-
Your doctor will ask about your symptoms and medical history. You will also have an exam. Tests may include the following:
- Electrocardiogram (ECG, EKG)
—a test that records the heart’s activity by measuring electrical currents through the heart muscle
- Holter monitor or event monitor
—an ambulatory monitor to record your heart rhythm that can be worn from 1-30 days to detect arrhythmias and correlate symptoms with the heart rhythm
- Exercise test
—particularly if the symptoms occur during physical activity
- Electrophysiology study
—an invasive test where monitoring wires are placed inside the heart and the heart's conduction system is tested directly
- Cardiac catheterization
—a tube-like instrument inserted into the heart through a vein or artery (usually in the arm or leg) to detect problems with the heart and its blood supply
Treatment
Talk with your doctor about the best treatment plan for you. Treatment options include the following:
Medications
The following medications are used to treat this condition:
- Beta-blockers (eg, atenolol, metoprolol, bisoprolol)
- Calcium channel blockers (eg, diltiazem, verapamil)
- Anti-arrhythmics, such as flecainide (Ambocor), procainamide (Procanbid), amiodarone (Cordarone), and sotalol (Betapace)
Ablation
Ablation
is done during an electrophysiology study. Radiofrequency energy or cold energy is used to destroy the abnormality and possibly cure the problem.
Implantable Cardioverter Defibrillator (ICD)
An
ICD
can be surgically placed into your body. This device monitors your heartbeat. It can apply a shock to correct an irregular heartbeat.
Prevention
Reducing risk of heart disease is the best way you can prevent this condition. Take the following steps:
RESOURCES
American Heart Association
http://www.americanheart.org
Heart Rhythm Society
http://www.hrsonline.org/
National Heart, Lung, and Blood Institute
http://www.nhlbi.nih.gov
CANADIAN RESOURCES
Canadian Cardiovascular Society
http://www.ccs.ca/home/index%5Fe.aspx
Heart and Stroke Foundation of Canada
http://www.heartandstroke.com/
References
Arrhythmia prevention. Heart Rhythm Society website. Available at:
http://www.hrspatients.org/patients/risk%5Ffactors/default.asp
. Accessed
April 19, 2007.
Implantable cardioverter defibrillator. American Academy of Family Physicians website. Available at:
http://familydoctor.org/270.xml
. Accessed
April 19, 2007.
Paroxysmal atrial tachycardia (PAT). EBSCO DynaMed website. Available at:
http://dynamed101.epnet.com/Detail.aspx?id=113613
. Accessed
April 19, 2007.
Ventricular tachycardia. EBSCO DynaMed website. Available at:
http://dynamed102.epnet.com/Detail.aspx?id=115268
. Accessed
April 19, 2007.
What are arrhythmias? American Heart Association website. Available at:
http://www.americanheart.org/presenter.jhtml?identifier=560
. Accessed
April 19, 2007.