1. Heart Disease (Coronary Artery Disease) Slideshow Pictures
2. Medical Illustrations of the Heart Image Collection
3. Take the Heart Disease Quiz!

Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

View Full Profile

Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

View Full Profile

Among individuals without known heart disease, arrhythmias are generally random, isolated occurrences that do not carry any significance. However, an evaluation by a physician is advised if a person notices any unusual or abnormal heart beats, especially if they reoccur or are sustained.

A variety of heart diseases cause arrhythmias. Heart disease can refer to patients with coronary artery disease, heart valve problems, heart failure, or disorders with heart conduction, or high blood pressure. Remember, however, that having an arrhythmia does not necessarily mean that a person has heart disease. Arrhythmias have many causes; sometimes the cause of an arrhythmia is never determined, other times the cause may be easy to determine and treat.

Sometimes, conditions other than heart disease may cause or aggravate arrhythmias. These conditions include the following:

• Infection or fever
• Physical or emotional stress
• Diseases such as anemia or thyroid disease
• Drugs and other stimulants, such as caffeine, tobacco, alcohol, cocaine, amphetamines, and certain over-the-counter and prescription medications, including medicine used to treat arrhythmias
• Certain arrhythmias can be genetically determined such as Wolff-Parkinson-White (WPW) syndrome.

Must Read Articles Related to Heart Rhythm Disorders

Anxiety Anxiety is a feeling of apprehension, fear, or worry. Some fears and worries are justified, such as worry about a loved one. Anxiety may occur without a cause, ...learn more >>

Atrial Fibrillation Atrial fibrillation (A fib) describes a rapid, irregular heart rhythm. The irregular rhythm, or arrhythmia, results from abnormal electrical impulses in the hea...learn more >>

Atrial Flutter Atrial flutter is an abnormality in the beating of the heart. Such abnormalities, whether in rhythm of heartbeat or speed of heartbeat, are known as arrhythmias...learn more >>

See the Entire Heart Rhythm Disorders Topic Guide »