Your heartbeat is induced by electrical impulses in your heart. When the heart’s electrical impulses don’t occur normally – when they’re too fast, too slow, or otherwise irregular – that condition is called “arrhythmia," which in turn causes the heart to beat erratically. 

Arrhythmia isn’t always serious, but it can be. When your heart doesn't beat properly, it can't pump blood effectively. And, if your heart doesn't pump blood effectively, this can create additional symptoms, and in rare cases, organ dysfunction. An unsynchronized heartbeat can cause symptoms such as a sensation of palpitations.

At Valley, we bring our extensive expertise to bear on helping you, and all our patients, discover the cause and best treatment for your particular arrhythmia. 

To determine which of the many types of arrhythmias you’re experiencing, we use state-of-the-art equipment to perform a variety of tests. We will make every effort to get the correct diagnosis for you, even if other institutions have failed to do so – and we won’t give up until we have.

Quick Refresher: Structure and Function of the Heart

In this section, we’ll be using some medical terms that assume a good deal of prior knowledge on your part, so here’s a quick review. Feel free to skip it if it’s not relevant to you by this point on your cardiac care journey.

The heart pumps the blood throughout the entire body, and has four chambers, two each on the right and left:

  • Atria (the upper chambers)
  • Ventricles (the lower chambers)

Between these chambers, the heart also has four valves that open and close to let blood flow in the correct direction when the heart contracts (beats).

Through a series of highly synchronized organized contractions of the four chambers, the heart pumps blood in a smooth and regular way to the lungs and all the body's tissues. What controls that organized beating sequence?

Electrical Signals Control the Pump

Anatomy of the heartThe heart begins to contract (beat) when an electrical impulse from the sinoatrial node, also known as the SA node or sinus node, (a group of cells located in the right upper atrium) moves through it. The SA node is referred to as the heart's "natural pacemaker" because it initiates impulses for the heartbeat. 

In normal situations, the electrical sequence then spreads throughout the atria to the atrioventricular or AV node (a group of specialized cardiac fibers found at the center of the heart.) 

From the AV node, electrical impulses travel through the bundle of His and split into the left and right bundle branches, directing the impulse to the respective left and right ventricles. The signals end at the Purkinje fibers and cause the ventricles, the lower chambers of the heart, to contract. (If either the right or left bundle branch fail to conduct the impulse properly or cause a delay in the signal, it is called a “bundle branch block”.)

That’s how the heart beats normally, but there are many ways for electrical short-circuits to happen, causing an arrhythmia (a condition that occurs when the natural pacemaker [the sinoatrial or SA node] develops an abnormal rhythm, the normal conduction pathway is interrupted, or another part of the heart takes over as pacemaker). 

Explore the many types of arrhythmias; tests available to diagnose arrhythmias; and treatments available at Valley.

Sinus bradycardia

Heart block

Sinus tachycardia

Supraventricular tachycardia

Multifocal atrial tachycardia

Atrial Fibrillation

Atrial Flutter

Ventricular tachycardia