PALPITATIONS

Introduction;

Heart is made up of four chambers.Two Atria and Two Venticles.

The atria (right atrium and left atrium) are the upper chambers of the heart.

• The right atrium receives venous blood from the body and pumps it into the right ventricle.
• The left atrium receives oxygenated blood from the lung and pumps it to the left ventricle.
• The ventricles are lower chambers of the heart.
• Each heart has two ventricles (right and left ventricles).
• The right ventricle pumps venous blood to the lung and the left ventricle pumps oxygenated blood to the rest of the body.

What is Pacemaker of the heart or SA node?



The SA node is the pacemaker of the heart and is located in the right atrium. The electrical signals initiated in the SA node are transmitted to the atria and the ventricles to stimulate heart muscle contractions (heartbeats). The AV node is specialized heart tissue which acts as an electrical relay station between the atria and the ventricles. Electrical signals from the SA node and the atria must pass through the AV node to reach the ventricles

 What are Palpitations?

Heart palpitations are sensations that feel like pounding or racing. Sometimes it feels like your heart skipped or stopped beats. Palpitations can be felt in your chest, throat, or neck.

Some persons with palpitations have no heart disease or abnormal heart rhythms and the reasons for their palpitations are unknown. In others, palpitations result from abnormal heart rhythms (arrhythmias).

Arrhythmias refer to heartbeats that are too slow, too rapid, irregular, or too early.

Rapid arrhythmias (greater than 100 beats per minute) are called tachycardias.

Slow arrhythmias (slower than 60 beats per minute) are called bradycardias.

Irregular heart rhythms are called fibrillations (as in atrial fibrillation).

When a single heartbeat occurs earlier than normal, it is called a premature contraction, and this can cause the sensation of a forceful heartbeat.

Abnormalities in the atria, the ventricles, and the electrical conducting system [the Sino-atrial (SA) node, and the Atrio-ventricular (AV) node] of the heart can lead to arrhythmias that cause palpitations

What are the Causes of Palpitations;

There are many causes of heart palpitations. The most common causes are:

• Exercise
• Anxiety
• Stress
• Heart Disease
• Caffeine
• Nicotine
• Cocaine
• Diet pills
• Hyperventilation
• Overactive thyroid
• Anemia
• Low levels of oxygen in your blood
• Medications
• Mitral valve prolapse

What are the Diagnostic tests for Palpitations?

• Blood Tests,
• Xray,
• ECG
• 2D Cardiac Echo
• Stress Test
• Holter or Event Moniter Test

What is a Holter or Event Monitor?

A standard ECG only records the heartbeat for a few seconds. It won't detect heart rhythm problems that don't happen during the test. To diagnose problems that come and go, your doctor may have you wear a Holter or event monitor.
A Holter monitor records the electrical activity of your heart for a full 24- or 48-hour period. You wear small patches called electrodes on your chest. Wires connect the patches to a small, portable recorder. The recorder can be clipped to a belt, kept in a pocket, or hung around your neck.
During the 24- or 48-hour period, you do your usual daily activities. You keep a notebook and note any symptoms you have and the time they occur. You then return both the recorder and the notebook to your doctor to read the results. Your doctor can see how your heart was beating at the time you had symptoms.
An event monitor is similar to a Holter monitor. You wear an event monitor while doing your normal activities. However, an event monitor only records your heart's electrical activity at certain times while you're wearing it.
For many event monitors, you push a button to start the monitor when you feel symptoms. Other event monitors start automatically when they sense abnormal heart rhythms.
Event monitors can be worn for 1 to 2 months, or as long as it takes to record your heart's activity during palpitations.

 

Medical Treatment for Palpitations

In most people, palpitations do not indicate underlying heart disease, and treatment other than reassurance or lifestyle changes is not needed. In some cases, your doctor may discover that your palpitations are due to an arrhythmia (irregular heartbeat) that warrants medical treatment.

The basic treatment for the management of most important arrhythmias are medications called "antiarrhythmics." These agents are generally classified according to their mechanism of action. There are four classes of these medications:

Class I antiarrhythmic drugs, known as "sodium channel blockers."

These medications have long been used to control arrhythmias. They work by blocking "sodium channels" (the transport of sodium across the cell walls) in order to slow impulse conduction in the heart
Eg-

• Lidocaine
• Flecainide

Class II antiarrhythmic drugs, known as "beta-blockers."

These medications slow the heart rate and force of contraction by decreasing the sensitivity of cells to adrenaline and adrenaline-like substances that act at beta receptors. Beta-blockers have long been used to control supraventricular tachycardias (SVTs), and recent evidence suggests they may be helpful in suppressing ventricular tachycardia and ventricular fibrillation

Eg-

• Atenolol
• Metoprolol

Class III antiarrhythmic drugs, known as "potassium channel blockers.

They work, in part, by prolonging the recovery time of cardiac cells after they have carried an impulse. This can prevent circuits (electrical pathways) from causing an arrhythmia or only permit slower arrhythmias

Eg-

• Amiodarone(It is the most widely used drug to treat atrial fibrillation)
• Sotalol

Class IV antiarrhythmic drugs, known as "calcium channel blockers."

These medications slow the heart rate by blocking heart cells' calcium channels (transport of calcium across the cell walls) and slowing conduction at the AV node.

• Verapamil

• Diltiazem 

In addition to these some other drugs are also used-

Digoxin - This medication increases the strength of heart muscle contractions and is useful in the treatment of heart failure. Because digoxin also slows conduction through the AV node, it may be useful in controlling atrial fibrillation, atrial flutter, and atrial tachycardia. It often is combined with beta- or calcium-channel blockers

Adenosine - This drug slows or blocks conduction through the AV node by acting on special adenosine receptors. Since adenosine is only available in intravenous form and only works for a short time, it is only used as acute treatment for supraventricular tachycardias


Prevention.

Try to reduce stress and risk factors for heart disease:

1. Don't smoke.
2. Eat a well-balanced, low-fat diet.
3. Exercise regularly.
4. Try stress management techniques such as yoga, or meditation.
5. Make sure that your blood pressure and cholesterol are under control.