The heart is a two stage electrical pump. The upper chambers of the heart, the atria, (single=atrium) collect blood from the body and pump it into the lower chambers, or ventricles. There is a little delay for the ventricles to fill, and then they pump the blood back to the body. For this to happen in a coordinated fashion, the heart has its own electrical system

Specialized electrical cells imbedded into part of the muscles in the atrium generate the electricity and act as a pacemaker for the heart. About 60-80 times a minute; this pacemaker (the sinoatrial or SA node) fires and sends electrical signals to all of the atrial muscle cells allowing them to fire at once, generating the first half of a heart beat. Electricity also travels to the ventricles but is held up for a split second in the junction between the atrium and ventricle at the atrio-ventricular node to allow the ventricles to fill with blood. Then the signal travels through electrical bundles to allow all the muscle cells of the ventricles to fire at once, causing the second half of the heart beat, and pumping blood to the body. There is then another split second when the electrical system resets itself to get ready for the next electrical impulse and heart beat.

Palpitations occur when a person can feel abnormalities in the normal beating of the heart. These palpitations can be an isolated extra beat, or they can run together and last for prolonged periods of time. Each part of the heart has the potential to be irritable and cause an extra beat to occur. As well, short circuits in the electrical conduction system of the heart can cause "runs" of abnormal firing.

The heart needs its normal environment to work well. If there are changes within or outside of the body, the heart's electrical system can be affected.

From within the body, abnormal levels of electrolytes like potassium, magnesium, and calcium can cause palpitations. Anemia and hyperthyroidism are also a potential causes of palpitations.

We live in a very chemical world, and many of the substances we put into our body appear to be adrenalin to the heart, and thus makes it irritable. Common stimulants include:

1. Caffeine
2. Tobacco,
3. Alcohol
4. Over the counter medications e.g. pseudoephedrine
5. Illicit drugs, cocaine being the most prevalent, although PCP and marijuana, among others, can cause palpitations as well.
6. The use of some prescription medications needs to be monitored, since their side effects can cause palpitations. Asthma medications like albuterol inhalers or theophylline and thyroid replacement medications are common causes of palpitations.
7. Times of stress can increase adrenalin levels in the body and cause rapid heart beats. These are physiologic and may be due to exercise, illness, or emotional stressors.

Palpitations are a symptom in and of themselves. They can be associated with an isolated skipped beat sensation or, if the palpitations are prolonged, there can be a feeling of fluttering or fullness in the chest. Prolonged episodes can be associated with chest pain, shortness of breath, sweating, and nausea and vomiting. Some types of heart rhythm problems can cause lightheadedness or even passing out.

As is often the case in medicine, the key to diagnosis is from the medical history.

1. When do the palpitations occur?
2. Do they come and go, or are they relatively isolated?
3. How long do they last?
4. What other symptoms are associated with them?
5. Are there ingestions, like caffeine, alcohol, medications, or drugs associated with the symptoms?
6. Are there any underlying medical problems that could be a potential cause?

Unless the palpitations are occurring during the visit to the healthcare provider, physical examination is not that helpful. The healthcare provider will likely check vital signs like pulse and blood pressure and look for signs of underlying physical problems, such as a goiter (enlarged thyroid gland in the neck) and listen to the heart to check for abnormal sounds like clicks or murmurs.

If the palpitations are present at the time of the visit to the healthcare provider, an electrocardiogram (ECG) and a heart monitor that records heart rate and rhythm will likely establish the diagnosis. If the palpitations have already resolved, the ECG and monitor may not necessarily be helpful. They may show normal results after the symptoms are gone.

Blood tests may be ordered to check hemoglobin and red blood cell counts for anemia, to determine whether there are any electrolyte abnormalities, to check kidney function (since abnormal kidney function may affect electrolyte levels), and to check thyroid function. The levels of certain medications may also be tested in the blood.

Self-Care at Home

Since there are numerous types of palpitations, the treatment is usually specific to the diagnosis. In those people with a yet undiagnosed palpitation, minor lifestyle changes may help minimize symptoms. These include stopping the use of caffeine, alcohol, and over the counter cold medications.

Patients with palpitations should try to keep a journal of when, where, and what circumstances surround their palpitations. They should learn how to take their pulse and document their pulse rate, whether the palpitations occur in isolation or in a pattern, and what associated symptoms exist, including lightheadedness, nausea, sweating, chest pain, or shortness of breath.

Chest pain (or any other signs of heart attack including jaw pain, indigestion, or extreme fatigue), shortness of breath, or passing out should prompt the patient or a family member to call 911 and seek medical attention immediately.
Medical Treatment

In the acute setting, for a person with a supraventricular tachycardia or atrial fibrillation, the goal is to slow the rate and establish the diagnosis. Sometimes, attempts will be made to use vasovagal maneuvers to block the adrenalin forces in the body. One such maneuver asks the patient to hold their breath while bearing down hard as if to have a bowel movement.

Adenosine can be given as a single intravenous injection that may reset the pacemaker cells and allow the heart to go back into a normal rhythm, or it may slow the heart rate temporarily to allow the doctor to define the heart rhythm and then suggest the appropriate medication for control or cure. Other medications that may be used include beta blockers and calcium channel blockers.

Some rhythms, like Wolfe-Parkinson-White SVT, have specific electrical short circuits that can be treated by the administration of high-frequency electrical energy ("burning") during heart catheterization and using high frequency ultrasound to ablate or destroy the abnormal electrical pathway and cure the problem. This is opportunity is limited to use in a few situations.

If the rapid heart rate is associated with chest pain, shortness of breath, or low blood pressure, an emergent situation exists, and electrical shocks may be administered with anesthesia to convert the heart to a more stable and slower rhythm.

Whether or not heart palpitations can be prevented will depend on the cause. Reducing stress and anxiety can help lessen your heart palpitations.