Palpitations are unpleasant sensations of irregular and/or forceful beating of the heart. 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.
- Tachycardia is rapid arrhythmias (greater than 100 beats per minute).
- Bradycardia is slow arrhythmias (slower than 60 beats per minute).
- Fibrillations are irregular heart rhythms (as in atrial fibrillation).
- Premature Contractions are when a single heartbeat occurs earlier than normal and can cause the sensation of a forceful heartbeat.
Palpitations are symptoms 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 (syncope).
Heart palpitations can be caused by:
- Anxiety, stress, fear
- Certain medications, including those used to treat thyroid disease, asthma, high blood pressure, or heart problems
- Diet pills
- Low levels of oxygen in your blood
- Heart valve disease, including mitral valve prolapse
- Overactive thyroid
How it is Diagnosed:
The key to diagnosis is from the medical history.
- When do the palpitations occur?
- Do they come and go, or are they relatively isolated?
- How long do they last?
- What other symptoms are associated with them?
- Are there ingestions, like caffeine, alcohol, medications, or drugs associated with the symptoms?
- 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.
For many people, there is a struggle to find out what heart rhythm is causing the palpitations. Inevitably, the symptoms do not always appear during the doctor's visit. Admission to the hospital is not usually effective, since lying in a hospital bed does not replicate the patient's function in their active world where the symptoms occur.
A variety of outpatient heart rate monitoring devices can be worn by the patient to try to capture and record abnormal beats. These rhythm strips are computer analyzed and may give clues as to the underlying cause of palpitations. Some types of monitors are worn for one or two days, while event monitors can be worn for a month. Occasionally a patient may have a device implanted under the skin for even longer monitoring.
What is the normal heartbeat?
The normal resting adult heart beats regularly at an average rate of 60-100 times per minute. How fast the heart beats (heart rate) is governed by the speed of electrical signals originating from the pacemaker of the heart, the SA node. The electrical signals from the SA node travel across the atria and cause these two upper heart chambers to contract, delivering blood into the lower heart chambers, the ventricles. These electrical signals then pass through the AV node to reach the ventricles. Electrical signals reaching the ventricles cause these chambers to contract, pumping blood to the rest of the body, generating the pulse. This regular flow of electricity from SA node to AV node causing a regular contraction of the heart muscle is known as a "sinus" beat.