Electrophysiology (EP) Services

Understanding the rhythms of the heart

Cardiac electrophysiology centers on the diagnosis and treatment of electrical disorders of the heart, which can affect the normal rhythm of heartbeats. When the heart beats faster than normal, it is called tachycardia. When the heart beats too slowly, it is called bradycardia. Many factors can affect your heart's rhythm, such as a prior heart attack, reduced heart pumping activity, valvular heart disease or high blood pressure. Some substances or medicines may also cause arrhythmias.

In addition to electrophysiology studies to help determine the cause of an abnormal heart rhythm and locate its origin, Fountain Valley Regional Hospital and Medical Center offers advanced EP treatment options based on the type of arrhythmia. 

Types of Arrhythmias 

Premature beats are the most common type of arrhythmia. Most of the time, and especially in healthy people, they're harmless, need no treatment, and often don't cause any symptoms. However, if frequent, they can result in weakening of the heart muscle. 

Supraventricular tachycardia (SVT) starts in the heart’s upper chambers (atria) or atrioventricular (AV) node. Types of supraventricular arrhythmias include atrial fibrillation (AFib or AF), atrial flutter, AV nodal reentrant tachycardia (AVNRT), AV reciprocating tachycardia (AVRT) and atrial tachycardia (AT). 

AF is the most common type of serious arrhythmia. It involves a very fast and irregular contraction of the atria. In addition to common symptoms of palpitations, shortness of breath, chest discomfort and generalized fatigue, AF has two major complications — stroke  and heart failure. Atrial flutter is often associated with and similar to atrial fibrillation in causing symptoms. However, the heart's electrical signals spread through the atria in a fast and regular — instead of irregular — rhythm. Atrial flutter is much less common than AF, but it has similar serious complications. 

Ventricular Arrhythmias start in the heart's lower chambers, the ventricles. They can be very dangerous and usually require emergent medical care. Ventricular arrhythmias include ventricular tachycardia (VT) and ventricular fibrillation (V-Fib). Coronary heart disease, prior heart attack, a weakened heart muscle and other structural heart diseases can cause ventricular arrhythmias. 

Bradyarrhythmias occur if the heart rate is slower than normal. If the heart rate is too slow, not enough blood reaches the brain. Bradyarrhythmias can be caused by: 

  • Heart attacks
  • Dysfunction of the heart’s own pacemaker, the sinoatrial node
  • Conditions that harm or change the heart's electrical activity, such as an underactive thyroid gland or aging
  • An imbalance of chemicals or other substances in the blood, such as potassium
  • Medicines such as beta blockers, calcium channel blockers, some antiarrhythmia medicines and digoxin 

(Information from the National Heart Lung and Blood Institute) 

Watch a video on cardiac arrhythmias. 

Cardiac rhythm procedures 

  • Device implantations and revisions including pacemakers, implantable ardioverter-defibrillators (ICDs) and biventricular pacemaker/ICDs for management of heart failure
  • Laser lead extraction
  • Simple ablations for right sided SVTs
  • Complex ablations for AFib, left sided atrial tachycardia/flutter and VT
  • Cardioversion 

Learn more about heart rhythm disorders and treatments.