Arrhythmias Symptoms, Treatment & Prevention

The heart normally contracts 60 to 100 times per minute. A problem in the heart's electrical system may result in abnormal heart rhythms, rate, or both. These are referred to as "arrhythmias". An arrhythmia can originate at any location throughout the conduction system.

An arrhythmia can occur when another part of the heart acts like a pacemaker and initiates a heartbeat. Arrhythmias also occur when the normal route of the signal is interrupted or blocked or forms a short circuit or when the SA node itself develops an abnormal rate.

Abnormal heart beats which originate in the atria are called "atrial" or "supraventricular arrhythmias". Those which originate in the lower chambers are called "ventricular arrhythmias".

You may be born with an arrhythmia or the pre-condition necessary to set up an arrhythmia. Some irregular rhythms result from underlying medical conditions such as heart disease or high blood pressure. Stress, caffeine, smoking, alcohol and some over the counter medications can cause arrhythmias.

Not all heart rate changes are abnormal Many people experience a variation in rate in the early morning. Their rates are lowest right before awakening, and highest, immediately after awakening.

How does my heart work?
The functioning of your heart involves two systems: the pumping system and the conduction or "electrical" system.

Blood is pumped throughout your body by the heart's four chambers: the two upper "atria" and the two lower "ventricles" The pumping system also includes four valves, which allow blood to flow through and out of your heart as it contracts and relaxes.

The electrical system creates signals that tell the chambers of your heart when to contract (beat). The signal begins in the heart's natural "pacemaker", a cluster of cells located in the right atrium, called the "sinoatrial node", "sinus node" or "SA node". The atria contract as the signal travels through them. Then the signal moves through another group of cells called the "atrioventricular node" or "AV node". This node slows the signal and sends it. through conductive fibers (bundle branches) in the ventricles to the muscle, which in turn, contracts.

What are the symptoms of an arrhythmia?
In general, arrhythmias can produce a variety of symptoms including palpitations, fainting, dizziness, weakness, shortness of breath, anxiety, chest pain or chest discomfort.

Palpitations may not always indicate the existence of an arrhythmia. You may be aware of your heart beat due to an increased force of contraction.

Some arrhythmias produce no symptoms. The presence and nature of symptoms depends on the type of arrhythmia, its severity, its frequency and its duration.

How are arrhythmias diagnosed?
Your doctor may make an initial diagnosis of an arrhythmia by conducting a medical history and physical. He will take your pulse and may measure the pressure of your jugular (neck) vein. He may take a blood test.. Some of the questions he will ask concern symptoms, the existence of other medical conditions, and whether you smoke or drink. Bring your current medications with you.

Diagnostic testing may include a standard electrocardiogram (ECG) This test characterizes and diagnoses the various types of arrhythmias.

A "signal-averaged" electrocardiogram allows your physician to ascertain whether your have low amplitude signals called, "late potentials". Late potentials represent delayed conduction through the diseased heart muscle.

Late potentials in survivors of acute heart attack indicate an increased risk for a type of arrhythmia called, "Ventricular Tachycardia" and for sudden death.

Your doctor may order Holter monitoring. This diagnostic test produces an ambulatory electrocardiographic recording over a 24 hour period. If your doctor suspects that you have a life-threatening arrhythmia, you will be hospitalized during the test.

Transtelephonic monitoring is long term monitoring which is used to document intermittent problems that may not be detected with 24 hour monitoring. Your doctor may order one of two devices, depending upon the type of arrhythmia he suspects you have. The first device is the size of a beeper. It records on a continuous loop of three minutes. When you experience symptoms, you push a button which freezes the recording tape. This is particularly effective, if you have just fainted. You then call an evaluation facility immediately and transmit your electrocardiographic recording over the telephone. The second device is worn like a wrist watch. This instrument only records electrical activity when you push the button. It can record up to two minutes at a time. This approach is effective in documenting longer lasting arryhthmias.

An Electrophysiology Study (EPS) is conducted when your physician suspects you have a serious sustained arrhythmia. An EPS is a diagnostic procedure which evaluates and records the electrical activity of your heart. This study provides information about the speed and pattern of your heart beat. During EPS, the operator can test a variety of drugs to determine the most effective medication for your arrhythmia.

Exercise testing and coronary angiography may be ordered to determine the existence of underlying coronary artery disease.

What is syncope?
Syncope is a sudden, brief loss of consciousness or fainting spell, due to insufficient blood flow and oxygen to the brain. Syncope occurs without warning. Certain arrhythmias - ventricular fibrillation, ventricular tachycardia and advanced AV block - can cause syncope.

"Tilt-table" testing may be used to evaluate syncope. During the test you lie strapped to a table that can be moved slowly to a near upright position in order to bring on syncope. Your symptoms, heart rate and blood pressure are continuously monitored throughout the test.

What are the different types of arrhythmias?
In general, the three types of arrhythmia are tachycardia (a rapid heartbeat), fibrillation (a chaotic, rapid heartbeat). and bradycardia (a slow heartbeat).

What is ventricular tachycardia?
Ventricular tachycardia consists of rapid but regular heart beats which originate in your ventricles. Your heart's pumping efficiency is diminished. You may feel faint, dizzy, lightheaded, or experience palpitations.

VT may be a life-threatening condition which may be converted into a normal rhythm with an electrical shock. Your doctor may prescribe medication or recommend the implantation of a therapeutic device.

What is paroxysmal superventricular tachycardia?
This form of tachycardia, also called paroxysmal atrial tachycardia, is a rapid heart beat that occurs and disappears suddenly. It is rarely life-threatening. Episodes can usually be shortened with a breathing technique called the Valsalva maneuver: Hold your breath, tighten your chest and bear down as though going to the bathroom.

What is ventricular fibrillation?
Ventricular fibrillation (VF) is an unstable heart rhythm in which your heart does not actually beat, but quivers. Disorganized electrical activity in the ventricles makes them contract in an uncoordinated fashion. Your heart stops pumping blood and you suffer a temporary loss of oxygen. You will usually pass out within a few seconds. It is fatal if not reversed in minutes by an electric shock. VF may be caused by severe coronary artery disease.

"Primary VF" develops due to problems in the heart's electrical system. "Secondary VF" develops from electrical problems secondary to some other heart problem.

What is atrial fibrillation?
"Atrial fibrillation" (AF) occurs when the atrial activity is handled in a disorganized way. This make the atria rapidly quiver. The quivering may last for a few seconds to hours or may never cease. If the abnormal arrhythmia occurs quickly only once in a while for a short period of time, this is called "Paroxysmal Atrial Fibrillation". The atria will not eject enough blood; the remaining blood may collect or "pool" Pooled blood can clot. If a clot forms, it may break off a piece to the brain, and a stroke or "brain attack" may occur. Atrial fibrillation is responsible for about 15 per cent of all strokes.

If you have AF, you may experience one or more of the following symptoms: palpitations, shortness of breath, chest pain or tightness, dizziness, lightheadedness or fainting.

AF is often caused by an underlying disease such as rheumatic heart disease, coronary artery disease, hypertension or hyperthyroidism . If the underlying condition is treated, the AF may be cured. Atrial fibrillation is rarely life-threatening.

Blood thinning medications such as aspirin and warfarin are recommended for the treatment of atrial fibrillation.

"Atrial flutter" occurs when your atrium beats quickly but evenly. The symptoms are similar to those of AF.

What is bradycardia?
Sometimes the heart beats too slowly. This is called, "bradycardia. This occurs when the electrical impulse is not formed in the SA node or it is not transmitted through the AV node to the ventricles.

You can be born with bradycardia or it can develop at any age. It is more prevalent among the elderly.

Bradycardia may be caused by scarring due to aging, infection of the valves, heart attack or heart disease. Certain medications such as antidepressants, can cause bradycardia. The heart rate may return to normal with cessation of the medications.

If you have bradycardia, you may feel faint, dizzy, lightheaded, or fatigued. Bradycardia often has no symptoms. In more serious cases when the heart rate is very low, atrial fibrillation can occur. Sometimes bradycardia results in death.

What is Wolff-Parkinson-White Syndrome?
You may have Wolff-Parkinson-White Syndrome (WPW), wherein an extra pathway exists between the upper and lower chambers of the heart, bypassing the AV node.. Electrical signals may short circuit via this abnormal connection and may arrive at the ventricles too soon. This can cause the heart to speed up. Sometimes the heart will be activated so quickly that the rhythm changes to ventricular fibrillation, resulting in immediate death.

Some people experience tachycardia as part of the syndrome. The tachycardia can be reversed by medicine or an electrical shock.

You may have symptoms which include: palpitations, syncope, shortness of breath, and lightheadedness.

WPW syndrome can be treated with a special procedure known as "radio frequency ablation".

What are premature ventricular contractions?
Premature ventricular contractions (PVC) are "extra" heartbeats arising from the ventricles. They interrupt the normal heart rhythm and cause an irregular beat.

If you have PVC you may feel the extra beat as a "missed beat" or a "flip-flop" in your chest.

If you have frequent PVC's the condition may progress to a more serious arrhythmia.

Ventricular bigeminy is a form of premature ventricular contraction in which a regular heart beat is paired with an extra or irregular beat. This rhythm usually does not lead to dangerous arrhythmias.

What is the long Q-T syndrome?
A prolongation in the heart's electrical recovery between beats is known as "long Q-T syndrome. If you have this syndrome, you may experience syncope or sudden death or no symptoms at all. The symptoms, may be brought on by exercise, intense emotion or a startling noise. Long Q-T syndrome is treated with medication and/or defibrillation. It is often inherited and thus is present at birth. Sometimes people with this condition are also deaf at birth.

What is sick sinus syndrome?
Sick sinus syndrome is a name given to a variety of illnesses, all of which involve the SA node, but which can involve the AV node or other parts of the heart as well. If you have sick sinus syndrome, you maybe symptom free or you may feel lethargic and fatigued. Sick sinus syndrome is sometimes characterized by a tachycardia alternating with bradycardia. You may also experience palpitations and syncope. Sick sinus syndrome is treated with medication and or a pacemaker.

How are arrhythmias treated?
In a few cases, cessation of a precipitating activity such as the use of alcohol or caffeine, will cure the arrhythmia.

You may be given one of the following drugs: Digoxin, calcium channel blocker, sodium channel blockers and beta blockers. The medicine. may have side effects. Call your doctor if you experience:: fatigue, nausea, constipation, headaches, ankle swelling, loss of appetite or especially dizziness. Lassitude is common when you begin taking beta-blocking agents, but it usually does not persist.

Many arrhythmias are cured by "Radiofrequency Ablation", a non-surgical treatment technique which involves the selective destruction of tiny areas of heart muscle, by the use of an electrical current. This technique eliminates or interrupts extra or inappropriate electrical pathways in the heart.

Implantable devices are used to correct severe, potentially fatal ventricular arrhythmias. An automatic implantable cardioverter defibrillator (AICD), continuously monitors your heart for any rapid and/or irregular heart rhythms and automatically delivers treatment.

A pacemaker is a small electronic device, which when implanted in your body, can generate electrical impulses to treat a slow heart rhythm.

Cardioversion is a technique whereby your doctor delivers a brief electric shock to your heart. The shock arrests the irregular heart beat. When your heart resumes beating, it beats in a normal rhythm.

You may be required to take anticoagulants for a few weeks prior to the cardioversion. You should refrain from eating or drinking after midnight of the day prior to the procedure.. If you do take medicine, use small sips of water.

Is surgery ever performed to treat arrhythmias?
In the unlikely event that .your arrhythmia is uncontrollable, you may have to undergo surgery.

Your doctor may recommend ventricular ressection in which the surgeon removes the site in the heart's muscle in which the arrhythmia originated.

Atrial fibrillation can be cured by "Maze" surgery in which a new electrical pathway is created.

What will my life me like with an arrhythmia?
Most people who have arrhythmias, lead normal lives. If you have an arrhythmia, you can swim and perform other exercise.

If you experience dizziness and fainting, your doctor may recommend that you refrain from driving until these symptoms are under control.

What are the statistics concerning arrhythmia?
According to the American Heart Association:

Approximately 4,300,000 Americans have arrhythmias.
There are 638,000 hospital admissions annually due to arrhythmias
The prevalence of atrial fibrillation is greater among men than among women, but the absolute number of men and women with it is about equal. About 70 percent of people with atrial fibrillation are between 65 and 85 years old.
There are more than 250,000 sudden cardiac deaths per year. Most are thought to be from ventricular fibrillation.