What is it?

• Heart palpitations are the feelings of having rapid, fluttering or pounding heartbeats. Heart palpitations can be triggered by stress, exercise, medication or, rarely, an underlying medical condition.
• Although heart palpitations can be worrisome, they're usually harmless, since your heart is still pumping effectively. You can often prevent heart palpitations by avoiding the triggers that cause them.
• In rare cases, heart palpitations may be a symptom of a more serious heart condition, such as an irregular heartbeat (arrhythmia), that may require treatment.

Symptoms

Heart palpitation symptoms can feel like:

• Skipped heartbeats
• Fluttering heartbeats
• Heartbeats that are too fast
• Heartbeats that are pumping harder than usual

You may feel heart palpitations in your throat or neck, as well as your chest. Heart palpitations can occur whether you're active or at rest, and whether you're standing, seated or lying down.

Causes

Often the cause of your heart palpitations can't be found. It's thought that common causes of heart palpitations include:

• Strong emotional responses, such as stress or anxiety
• Strenuous exercise
• Caffeine
• Nicotine
• Fever
• Hormone changes associated with menstruation, pregnancy or menopause
• Taking cold and cough medications that contain pseudoephedrine, a stimulant
• Taking some asthma inhaler medications that contain stimulants

However, occasionally heart palpitations can be a sign of a serious, underlying problem, such as an overactive thyroid gland (hyperthyroidism) or an abnormal heart rhythm (arrhythmia). Arrhythmias may include very fast heart rates (tachycardia), unusually slow heart rates (bradycardia) or an irregular heart rhythm (atrial fibrillation).

Risk factors

You may be at risk of developing palpitations if you:

• Are highly stressed
• Have an anxiety disorder or regularly experience panic attacks
• Are pregnant
• Take medicines that contain stimulants, such as some cold or asthma medications
• Have hyperthyroidism (overactive thyroid gland)
• Have other heart problems, such as an arrhythmia, a heart defect or a previous heart attack

Complications

Unless your heart palpitations are a sign of an underlying heart condition, there's little risk of complications.

If your palpitations are a sign of an underlying heart condition, possible complications include:

• Fainting. If your heart beats very quickly, your blood pressure may drop, causing you to faint. This may be more likely if you have a heart problem, such as congenital heart disease or certain valve problems.
• Cardiac arrest. Rarely, palpitations can be caused by life-threatening arrhythmias and can cause your heart to stop beating effectively (cardiac arrest).
• Stroke. If palpitations worsen so that your heart quivers instead of beating properly, it can cause blood to pool. This can cause blood clots to form. If a clot breaks loose, it can travel to and obstruct a brain artery, causing a stroke. This may damage a portion of your brain or lead to death.
• Heart failure. This can result if your heart is pumping ineffectively for a prolonged period due to an arrhythmia that's causing your palpitations, such as atrial fibrillation. Sometimes, controlling the rate of an arrhythmia that's causing heart failure can improve your heart's function.

Diagnosis

If your doctor thinks you have heart palpitations, he or she will first listen to your heart using a stethoscope to see if your heart's beating irregularly or too quickly. Your doctor may also look for signs of medical conditions that can cause heart palpitations, such as a swollen thyroid gland.

Other tests your doctor may perform include:

• Electrocardiogram (ECG). In this noninvasive test, a technician will place probes on your chest that record the electrical impulses that make your heart beat. An ECG records these electrical signals and can help your doctor detect irregularities in your heart's rhythm and structure that could cause palpitations. You may have an ECG while you're at rest or while exercising (stress electrocardiogram).
• Holter monitoring. A Holter monitor is a portable device that you wear to record a continuous ECG, usually for 24 to 72 hours. Holter monitoring is used to detect heart palpitations that aren't found during a regular ECG exam.
• Event recording. If you don't have any irregular heart rhythms while you wear a Holter monitor, your doctor may then recommend an event recorder. You wear an event monitor as much as possible throughout the day, and push a button on a recording device you wear on your belt to record your heartbeat when you experience symptoms. You may need to wear an event monitor for several weeks.
• Chest X-ray. A chest X-ray may be done to look at the size and shape of your heart to help determine if your heart structure is abnormal, which may cause palpitations.
• Echocardiogram. This noninvasive exam, which includes an ultrasound of your chest, shows detailed images of your heart's structure and function. Ultrasound waves are transmitted, and their echoes are recorded with a device called a transducer that's held outside your body. A computer uses the information from the transducer to create moving images on a video monitor.

References:

http://www.medicinenet.com/palpitations_overview/article.htm

http://www.healthline.com/symptom/palpitations

http://www.irishhealth.com/article.html?id=4144

https://www.hse.ie/eng/health/az/H/Heart-palpitations/

https://www.nlm.nih.gov/medlineplus/ency/article/003081.htm