By Dr. Patricia Knott
The human heart beats approximately 2.5 billion times during a person's lifetime. The normal heart rate is 60-100 beats per minute. The average female rate is 75 beats per minute.
When your doctor puts the stethoscope to your chest, he/she listens for the normal "lub-dub" sound the heart makes and is able to tell if the heart rate is too fast or slow, and if there are abnormal sounds which may indicate certain disease processes.
Your physician is not only concerned about how fast the heart is beating (the rate) but also whether the heart has a normal rhythm. When the heart does not beat in its regular pattern it is said to have an irregular rhythm. The most common irregular heart rhythm is called atrial fibrillation (AF) and affects approximately 2.2 million individuals in the United States.
The heart has an electrical conduction system which causes the contraction that gets the blood pumped throughout the body. The initial impulse originates in the part of the heart called the atrium at the sinoatrial node. The atrium empties blood into the ventricle, then the ventricle contracts to empty the blood into the aorta which sends it throughout the body. AF occurs when rapid random discharges are produced by larger areas of the atrium.
The symptoms associated with atrial fibrillation include one or more of the following: palpitations, irregular pulse, shortness of breath, weakness, fatigue, dizziness, fainting, and chest pain.
Risk factors for AF include age greater than 60, heart valve disease, high blood pressure, pneumonia, lung disease (COPD, asthma, pulmonary embolus), diabetes mellitus, congenital heart disease, heart failure, and hyperthyroidism. Alcohol use and use of stimulants such as nicotine and caffeine can increase the risk of AF as well. It can also occur in 10% of people without any heart or other health problems.
Your doctor can diagnose AF by a simple EKG after noticing an irregular rhythm on physical exam.
Once the diagnosis of AF is made, your physician has to make a decision about how to best treat the condition. This will depend on your medical history, how long the irregularity has been going on, and your symptoms. AF can increase the risk of heart failure, heart attack, and stroke so it is important to diagnose and treat the condition as soon as possible.
The risk factors for AF indicate what the preventative measures should be. Proper nutrition is important. Work with your doctor to treat hypertension or other medical conditions. Lower your stress level. Exercise and avoid stimulants like nicotine and caffeine. If you are age 55 or over and have other stroke risk factors, check your pulse rate once a month.
In order to check your resting pulse rate, you should first rest quietly for at least 10 minutes. Place 2 fingers (do not use the thumb) to the inside of the wrist below the thumb and feel for the beats pulsating through the artery located here. Count these beats while looking at the second-hand of a watch, counting for thirty seconds. Multiply this number by 2 to get the beats per minute that is your pulse rate. You may also count for 15 seconds and multiply the number by 4.
Practice taking your pulse at various times including at rest or with activity. Your pulse should increase with exercise. Remember however, that the heart not only has a normal rate or speed but it also has a rhythm. Contact your physician if you notice an irregularity in yours. Unlike dance where some people have better rhythm than others, our heart has a normal rhythm and our health can depend on a lack of deviation from that rhythm.
The following treatment options are available for AF:
â€¢ Cardioversion (medication or low voltage electrical shock to return the heart to a regular rhythm) - The physician may use this method if it has been less than 48 hours since onset. If longer than this, anticoagulation for several weeks may be advised.
â€¢ Anticoagulation (blood thinner) - Coumadin prevents formation of a blood clot in the atrium which could then travel to the brain and cause a stroke. Most people with intermittent or chronic AF take Coumadin. If there is low risk of stroke or the patient cannot take Coumadin, the physician may use aspirin to prevent a stroke.
â€¢ Rate control medicines - Metoprolol, Cardizem, Verapamil, and Digoxin are commonly used to control the fast heart rate that may occur with AF.
â€¢ Rhythm Control Medicines - These may be used if rate control has not been successful.
â€¢ Catheter Ablation (destroys tissue that causes AF) - Used if rate or rhythm control has failed. It should be performed at a medical center with experienced staff.
â€¢ Maze procedure (causes formation of scar tissue which blocks the multiple electrical impulses) - This is a surgical procedure and is usually done during heart surgery.