How does a normal heart beat?

Heart muscle cells are activated by electrical impulses that cause them to contract regularly and in sync. This contraction produces a heartbeat, allowing blood to be pumped out to the entire body.

Electrical impulses originate from specialized cells called the sinoatrial (SA) node, which is the heart’s natural pacemaker.

The SA node is located in the upper right chamber of the heart, the right atrium. From the SA node, the impulse spreads across the upper chambers of the heart to reach the atrial-ventricular (AV) node located between the atria and lower ventricles. After leaving the AV node, impulses spread across the pumping chambers of the heart, the ventricles.

As impulses are spread along the heart, the cardiac muscle cells are stimulated to contract, producing a heartbeat.

Animation of How a Normal Heart Beats


Conditions in which the heart beats with an irregular or abnormal rhythm. Some arrhythmias occur without symptom while others have symptoms of increasing severity.

Understanding normal electrical conduction through the heart

Causes of Arrhythmias

Disease, injury or any condition that disrupts normal conduction or creates a lack of oxygen to the heart tissue cells responsible for heart rate. Excessive physical and mental stress. Alcohol and drug abuse may also be a factor to consider in causes of some arrhythmias

Common Symptoms

Include, but not limited to, palpitations, chest tightness or peain, shortness of breath, lightheadedness, fainting or black-out, fatigue, exercise intolerance and excessively slow or fast heart rates, Symptoms may be constant, persist frequently or be infrequent and random which may require patient to be monitored to catch the moments when symptoms appear, This may be done with a Holter or Event monitor, or an implanted event recorder to capture the specific arrhythmia with it happens to confirm diagnosis.


The electrocardiogram is used to measure conduction through the heart and help identify any aberrancy.

Atrial Fibrillation

Atrial fibrillation is a relatively common abnormal heart rhythm where the atria beat quickly, irregularly, and unevenly.

Atrial Flutter

Atrial flutter is a relatively common abnormal heart rhythm where the atria beat quickly, but evenly. This is similar to atrial fibrillation, but the atria beat quickly and unevenly.


An echocardiogram (ECHO) is a simple diagnostic study used to assess the condition and function of the heart using high frequency waves.

Electrocardiogram (EKG or ECG)

An electrocardiogram is a test that measures the electrical activity of the heartbeat. An electrical impulse, or “wave,” is created and moves through the heart with every beat. The heart muscle is squeezed by these waves pumping blood to the rest of the body. The timing of the top and lower chambers pumping is what is shown on a on an ECG.

Ablation of Atrial Fibrillation

There is an epidemic of atrial fibrillation and may reduce quality of life, increased risk of stroke, heart failure, and even death. Atrial fibrillation results in adverse atrial remodeling and eventually leads to persistence of atrial fibrillation making it more difficult over time. Catheter ablation has evolved to be a safe procedure in experienced centers, but we need to do it carefully.


Cardioversion is a procedure used to treat abnormal and rapid heart rhythms known as cardiac arrhythmias. Cardioversion is most commonly used for atrial fibrillation. Cardioversion delivers an electrical ‘shock’ to the heart to restore the heart to its normal rate and rhythm.

Event Monitor

A cardiac event monitor is a small portable device worn by patients during their normal activity for up to 30 days. This device is capable of recording the electrical activity of the heart in the form of an electrocardiogram (EKG) for up to several minutes. This is intended to record arrhythmias (abnormal heart rhythm) that would not be found on a routine EKG or to record an arrhythmia that is so infrequent, it is not detected on a 24 hour Holter monitor.


A pacemaker is a small device that sends electrical impulses to the cardiac muscle. This helps to regulate a normal heart rate and rhythm.

Cardiac Medications

This list is for information only and includes only the most common medications used in treating cardiovascular disease. You should always speak with your healthcare provider and/ or pharmacist for more detailed information on your medications.