Park's Pediatric Cardiology for Practitioners, 6th Ed.

Palpitation

Definition

Palpitation is an unpleasant subjective awareness of one’s own heartbeats. This usually occurs as a sensation in the chest of rapid, irregular, or unusually strong heartbeats. The patient describes it as pounding, jumping, racing, irregularity of the heartbeat, a “flip flopping” or “rapid fluttering“ in the chest, or pounding in the neck. Palpitation can be felt in the chest, throat, or neck. The pulse rate may become faster or rarely slower than normal. The term palpitation is used so loosely that specific questions must be asked to determine the exact nature of the symptom.

Causes

Palpitation is one of the most common cardiac symptoms encountered in medical practice, but it poorly corresponds to demonstrable abnormalities. Many palpitations are not serious. However, palpitation may indicate the possible presence of serious cardiac arrhythmias.

Box 32-1 lists causes of palpitation. The differential diagnosis can range from benign etiologies to life-threatening arrhythmias.

• A high percentage of patients with palpitation have no cause that can be established.

• Caffeine, a common stimulant, is found in many foods and drinks, such as coffee, tea, hot cocoa, soda, chocolate, and some medicines. Most energy drinks (e.g., Venom, Whoopass, Red Bull, Adrenalin Rush), which are the latest popular fad among youth, contain large doses of caffeine and other legal stimulants, including ephedrine, guarana, taurine, and ginseng.

• Certain drugs and substances can be identified as causes of palpitation.

• Some medical conditions, such as hyperthyroidism, anemia, and hypoglycemia, may be the cause of palpitation.

• Although relatively rare, cardiac arrhythmias and structural heart disease should be looked into as a cause of palpitation. However, most palpitations are not accompanied by arrhythmias, and most arrhythmias are not perceived and reported as palpitations.

• Rarely, slow heart rates may cause palpitation.

• Occasionally, a psychogenic or psychiatric cause for the symptoms can be suspected. Some adult patients and adolescents with palpitations have panic disorder or panic attack. Panic attack and arrhythmias may be difficult to distinguish clinically because both may present as palpitations, shortness of breath, and lightheadedness.

Evaluation

History

In a child who is old enough to provide a detailed history, careful history taking often suggests possible causes. Palpitation usually occurs without other symptoms. However, the presence of additional symptoms such as dizziness, fainting, nausea, sweating, chest pain, shortness of breath, and so on may be more significant.

1. The nature and onset of palpitation may suggest causes.

a. Isolated “jumps” or “skips” suggest premature beats.

b. A sudden start and stop of rapid heartbeat or a pounding of the chest suggests supraventricular tachycardia (SVT). Some children appear sweaty or pale with SVT.

BOX 32-1 Causes of Palpitation

Normal Physiologic Events

Exercise, excitement, fever

Psychologic or Psychiatric

Fear, anger, stress, anxiety disorders, panic attack or panic disorder

Certain Drugs and Substances

Stimulants: caffeine (coffee, tea, soda, chocolate), some energy drinks, smoking.\

Over-the-counter drugs: decongestants, diet pills, and so on

Drugs that cause tachycardia: catecholamines, theophylline, hydralazine, minoxidil, cocaine

Drugs that cause bradycardia: beta-blockers, antihypertensive drugs, calcium channel blockers

Drugs that cause arrhythmias: antiarrhythmics (some of which are proarrhythmic), tricyclic antidepressants, phenothiazines

Certain Medical Conditions

Anemia

Hyperthyroidism

Hypoglycemia

Hyperventilation

Poor physical condition

Heart Diseases

Certain congenital heart defects that are prone to arrhythmias or that result in a poor physical condition

After surgeries for congenital heart disease: Fontan connection, Senning operation

Mitral valve prolapse

Hypertrophic cardiomyopathy

Dilated cardiomyopathy

Valvular disease: aortic stenosis

Cardiac tumors or infiltrative diseases

Cardiac Arrhythmias

Tachycardia

Bradycardia

Premature atrial contractions

Premature ventricular contractions

Supraventricular tachycardias

Ventricular tachycardias

Atrial fibrillation

Wolff-Parkinson-White preexcitation

Sick sinus syndrome

c. A gradual onset and cessation of palpitation suggest sinus tachycardia or anxiety state.

d. When the rate is known to be normal and the rhythm is regular, an anxiety state is the cause.

e. Palpitation characterized by slow heart rate may be caused by atrioventricular (AV) block or sinus node dysfunction.

2. Relationship to exertion:

a. A history of palpitation during strenuous physical activity may be a normal phenomenon (caused by sinus tachycardia), although it could also be caused by exercise-induced arrhythmias.

b. Nonexertional palpitation may suggest atrial flutter or fibrillation, febrile state, thyrotoxicosis, hypoglycemia, or anxiety state.

c. A rapidly developing palpitation, although not abrupt, unrelated to exertion or excitement, may occur with hypoglycemia or tumor of adrenal medulla.

d. Palpitation on standing suggests postural hypotension (or orthostatic intolerance).

3. Associated symptoms:

a. Symptoms of dizziness or fainting associated with palpitation may indicate ventricular tachycardia.

b. The presence of other symptoms, such as chest pain, sweating, nausea, or shortness of breath. maybe more significant and may increase the likelihood of identifiable causes of palpitation.

4. Personal and family history may help identify the cause.

a. Ask about eating and drinking habits, such as sodas, coffee, tea, hot cocoa, and chocolates, which contain caffeine.

b. Ask if the patient is taking energy drinks.

b. Ask about prescription and over-the-counter medications that could cause palpitation.

c. Ask about medical or heart conditions that may cause tachycardia or palpitation (listed in Box 32-1).

d. Ask about family history of syncope, sudden death, or arrhythmias.

Physical Examination

1. Most children with palpitation have normal physical examinations except for those with hyperthyroidism.

2. Cardiac examination may reveal findings of mitral valve prolapse (MVP), obstructive lesions, or possibly cardiomyopathy.

Recording of Electrocardiography Rhythm

Recording of electrocardiography (ECG) rhythm that coincides with the timing of the patient’s complaint of palpitation is a certain way of making a diagnosis of arrhythmia or ruling it out as the cause of palpitation. A number of different ECG recording techniques are available.

1. Routine ECG during office visit: Check for prolonged QTc interval, delta waves (Wolff-Parkinson-White preexcitation), and AV block.

2. When palpitation occurs almost daily, especially when associated with symptoms, 24-hour Holter monitoring is usually most helpful in making the diagnosis of the rhythm abnormality. This may clarify the diagnosis and secure management plans. Some children actually complain of palpitation during sinus tachycardia.

3. When palpitation occurs infrequently, long-term event monitor recording (up to 30 days) is indicated. With infrequent palpitations that are fairly long lasting, handheld or patient-activated event recorders are indicated. However, with infrequent short-lasting palpitation, external loop recorders are indicated.

4. Implantable loop recorder (inserted under the skin at about the second rib on the left front of the chest) can be used to monitor for a period longer than 1 month (may be up to 1 year). This can be worn during swimming or other vigorous exercises.

5. Continuous outpatient telemetry monitoring is a new monitoring modality available at most tertiary care facilities. The patient is fitted with a transmitter that sends the ECG data to the area of hospital where the telemetry monitoring occurs. The patient can move around within the device’s transmitting range.

6. If the symptoms occur during exercise, an exercise stress test may be helpful in making the diagnosis.

7. If there is a high suspicion of ventricular tachycardia, sometimes provocative electrophysiologic studies may be indicated.

Echocardiography

Echocardiography studies help identify possible structural heart disease that may cause arrhythmias, such as hypertrophic cardiomyopathy, dilated cardiomyopathy, cardiac tumors, MVP, and other structural abnormalities of the heart.

Laboratory Studies

When other medical conditions are suspected as a cause of palpitation, a complete blood count (for anemia), electrolytes, blood glucose, and thyroid function testing may be indicated.

Management

1. If the rhythm recorded on the 24-hour Holter monitoring shows sinus tachycardia during the complaint of palpitation, all one has to do is to reassure the parent and child of the normal, benign nature of palpitation. Some parents are unaware of the fact that children’s heart rates are faster than adults’ heart rates and that children’s heartbeats are easily palpable when they place their palms over the child’s chest.

2. For isolated premature atrial contractions or premature ventricular contractions, nothing needs to be done except to avoid stimulants such as caffeine, excessive amounts of soda, or energy drinks. If they are so frequent that they are a hindrance to normal daily living, a beta-blocker could be tried.

3. When a significant cardiac arrhythmia or an AV conduction disturbance is the suspected cause of palpitation, further evaluation and therapy are guided by recommendations discussed in Chapters 24 and 25.

4. Examination of all medications that the patient is taking may be helpful in the diagnosis and in modifying the dosage or schedule or changing it to other medications.

5. If palpitation is associated with symptoms, such as fainting, dizziness, chest pain, pallor, or diaphoresis, further evaluation is guided as described in Chapters 30 and 31.