John M. Miller MD FACC


Atrial Fibrillation

Atrial fibrillation (say “AY-tree-uhl fih-bruh-LAY-shun”) is a type of irregular heartbeat (arrhythmia) in which the heart’s upper chambers quiver, or fibrillate. This increases the risk of blood clots, which can cause a stroke or other problems. The lower chambers beat without a regular rhythm and may beat too fast…

Supraventricular Tachycardia

What is supraventricular tachycardia? Supraventricular tachycardia (SVT) means that from time to time your heart beats very fast for a reason other than exercise, high fever, or stress. For most people who have SVT, the heart still works normally to pump blood through the body. Types of SVT include: Atrioventricular…

Electrical System of the Heart

In the normal heart, electrical impulses pace the rhythm at which the heart contracts and relaxes. The sinoatrial (SA) node triggers the electrical impulse, causing the upper chambers (atria) to contract. The signal travels through the atrioventricular (AV) node to the atrioventricular bundle, which divides into the…

Heart Rhythm Problems: Diary of Symptoms

If your doctor thinks you might have a heart rhythm problem, he or she may ask you to keep a diary of symptoms. This information can help your doctor find out what type of rhythm problem you have. And if you have a rhythm problem, a symptom diary can help you keep track of your condition. You can then discuss your…