Most people have had an irregularity of the heart’s rhythm at one time or another. These changes are hardly ever noticed and are seldom serious. An irregular heart rhythm does not necessarily mean that heart disease is present or that elaborate medical tests or treatments are required.
Doctors call any irregularity of the heart rhythm an “arrhythmia” (pronounced ah-rith’me-ah). Whenever a person is aware of the heart’s beating, doctors speak of this feeling as “palpitations.”
You can be sure that doctors know more about heart rhythms today than ever before. In most cases simple tests provide a diagnosis and often no treatment is necessary, especially when the heart is otherwise healthy and free of damage. In other cases, when heart problems are truly present, newer diagnostic tests, medications and devices are making these problems totally manageable.
This contains information for patients and their families and loved ones. It can help answer many of the common and important questions about palpitations and arrhythmia that all too often trouble patients or those caring for them. The information can relieve much anxiety and fear that come from “not knowing.” It can give patients a better understanding of arrhythmia, their doctors’ approach to diagnosis and treatment and guide them to a more active role in caring for their own health.
Please understand that this contains a great deal of information. It is not supposed to be read quickly or all at one sitting. It can be referred to over and over again. So, take you time. First, go to the sections you are most interested in. Then, when time permits and more questions occur to you, look into other chapters. The advantage of having this all “written down” is that you can get to know and understand more at your own pace!
Palpitations: Often normal
Step by step: From symptoms to diagnosis
Abnormal heart rhythms: How you might feel
Abnormal heart rhythms: How many are there?
Causes of abnormal heart rhythms
Tests to help diagnose the type of arrhythmia
How much rest and exercise are good for me?
Caffeine, alcohol and nicotine
Medications for the TOP of the heart
Medications for the BOTTOM of the heart
Implant devices: Technology takes yet another giant step!
Surgery to treat arrhythmia
A personal message
About the authors
Normal heart function: The beat goes on and on
The heart is a pump
The normal heart functions as a pump. It has four chambers, or cavities: two on the right side and two on the left. The chambers on the right (called the right atrium and right ventricle) receive blood from the body and pump it to the lungs to get oxygen and get rid of carbon dioxide. Blood coming back from the lungs, laden with oxygen, comes first to the left atrium and then to the left ventricle, which pumps the blood throughout the body. The left ventricle is the most powerful chamber in the heart.
Arteries carry blood away from the heart; veins carry blood from the body back to the heart. The four valves of the heart separate the chambers from each other and separate the chambers from the blood vessels they pump blood into. The heart’s valves are delicate but strong “one-way doors” that prevent the backflow of blood into the chamber it was just pumped from.
The heart has a “spark plug”
Without an electrical “jump start” for each beat, the heart muscle would not move. The essential “spark of life” is provided by a small group of cells called a “node” that acts like a “spark plug” or natural pacemaker. Located near the top of the right atrium, this structure is called the SA (for sinoatrial, pronounced “sigh”no-ay’tree-al”) node or “sinus node” for short.
Every second or so, the SA node produces a tiny electrical impulse that starts the heart beat. The electrical impulse travels along pathways starting at the top of the heart muscle, then through the middle of the heart (junction) and to the bottom. The junction between the top of the heart (atrium) and bottom of the heart (ventricle) is called the AV (atrioventricular) junction. The impulse leaves the junction and travels onto the pathways of the ventricle. As the impulse travels along it spreads throughout the muscle, which responds with a contraction (squeeze) that pushes the blood through the one-way valves. The entire sequence takes about three-tenths of a second at usual heart rates. After a brief recovery, the process starts all over again for the next beat.