Palpitations are perceived abnormalities of the heartbeat characterized by awareness of cardiac muscle contractions in the chest.
They are characterized as hard, fast and/or irregular beatings of the heart.
Symptoms include an abnormally rapid or irregular beating of the heart.
Palpitations are a sensory symptom.
Palpitations are a common complaint in the general population, particularly in those affected by structural heart disease.
Clinical presentation is divided into four groups: extra-systolic, tachycardic, anxiety-related, and intense.
Anxiety-related is the most common.
They are often described as a skipped beat, rapid fluttering in the chest, pounding sensation in the chest or neck, or a flip-flopping in the chest.
Palpitations are described in many ways: flip-flopping in the chest, a rapid fluttering in the chest, or pounding in the neck.
The symptoms may provide a clue the etiology of the palpitations, and the pathophysiology of each of these descriptions is thought to be different.
Palpitations can be associated with anxiety.
Palpitations do not necessarily indicate a structural or functional abnormality of the heart.
Palpitations can be a symptom arising from an objectively rapid or irregular heartbeat.
Palpitations can be intermittent, of variable frequency and duration, or continuous.
Associated symptoms to palpitations include dizziness, shortness of breath, sweating, headaches and chest pain.
Palpitation may be associated with: coronary heart disease, hyperthyroidism, hypertrophic cardiomyopathy, diseases causing low blood oxygen such as asthma and emphysema; previous chest surgery; kidney disease; blood loss and pain; anemia; drugs such as antidepressants, statins, alcohol, nicotine, caffeine, cocaine and amphetamines; electrolyte imbalances of magnesium, potassium and calcium; and deficiencies of nutrients such as taurine, arginine, iron, vitamin B12.
Palpitations may be described as flip-flopping, which is caused by premature contraction of the atrium, or ventricle, and the perception of the stop from the pause following the contraction and the start from the subsequent forceful contraction.
Rapid regular fluttering in the chest, suggests supraventricular or ventricular arrhythmias, including sinus tachycardia, and irregular fluttering suggests the presence of atrial fibrillation, atrial flutter, or tachycardia with variable block.
Pounding sensation in the neck, or neck pulsations, are often due to cannon A waves in the jugular venous, pulsations that occur when the right atrium contracts against a closed tricuspid valve.
When palpitations are associated with chest pain , it suggests coronary artery disease.
Palpitations with chest pain relieved by leaning forward, suggests pericardial disease.
When palpitations are associated with light-headedness, fainting or near fainting suggests low blood pressure and may signify a life-threatening abnormal heart rhythm.
Recurring palpitations that occur regularly with exertion suggests a rate-dependent bypass tract or hypertrophic cardiomyopathy.
Ambulatory monitoring or prolonged heart monitoring in the hospital might be warranted to evaluate palpitations.
Palpitations may be caused by non-cardiac factors, responding to a metabolic or inflammatory process.
Palpitations can be precipitated by non-cardiac problems of vomiting, or diarrhea with secondary electrolyte and volume disorders, hyperthyroidism, and panic disorders.
The neural pathways responsible for the perception of the heartbeat is hypothesized to include different structures located both at the intra-cardiac and extra-cardiac level.
Palpitations are a widely diffused complaint and particularly in subjects affected by structural heart disease.
The list of etiologies of palpitations is long, and in some cases, the
etiology of palpitations is often unable to be established:
In one study reporting the etiology of palpitations, 43% were found to be of cardiac etiology, 31% of psychiatric etiology and approximately 10% were classified as miscellaneous-medication induced, thyrotoxicosis, caffeine, cocaine, anemia, amphetamine, mastocytosis/
Cardiac cause of palpitations are the most life-threatening and include:
ventricular sources-premature ventricular contractions (PVC), ventricular tachycardia and ventricular fibrillation
atrial sources-atrial fibrillation, atrial flutter
high output states-hyperthyroidism, anemia, AV fistula, Paget’s disease of bone or pregnancy
structural abnormalities-congenital heart disease, cardiomegaly, aortic aneurysm, or acute left ventricular failure
Miscellaneous sources-postural orthostatic tachycardia syndrome abbreviated as POTS, Brugada syndrome, and sinus tachycardia.
A palpitation can be attributed to one of four main causes:
Extra-cardiac stimulation of the sympathetic nervous system by the inappropriate stimulation of the sympathetic and parasympathetic nervous system: particularly the vagus nerve which innervates the heart.
Such stimulation can be caused by anxiety and stress due to acute or chronic elevations in glucocorticoids and catecholamines.
Gastrointestinal distress such as bloating or indigestion, along with muscular imbalances and poor posture, can also irritate the vagus nerve causing palpitations.
Sympathetic overdrive due to a panic disorder, low blood sugar, hypoxia, antihistamines, anemia, heart failure, and mitral valve prolapse.
Hyperdynamic circulation associated with valvular incompetence, thyrotoxicosis, hypercapnia, high body temperature, anemia, count, pregnancy.
Abnormal heart rhythms of ectopic beats, premature atrial contractions, junctional escape beats, premature ventricular contractions, atrial fibrillation, supraventricular tachycardia, ventricular tachycardia, ventricular fibrillation, and heart block.
Palpitations can occur during times of catecholamine excess-exercise or at times of stress.
Palpitations during catecholamine excess is often related to a sustained supraventricular tachycardia or ventricular tachyarrhythmia.
Supraventricular tachycardias can also be induced at the termination of exercise when the withdrawal of catecholamines is coupled with a surge in the vagal tone.
Palpitations secondary to catecholamine excess cam occur during emotional distress or startling experiences, especially in patients with a long QT syndrome.
Adrenaline, a natural hormone released during periods of emotional and physical stress, can cause palpitations as a result of its effects on the parasympathetic nervous system.
Anxiety and stress elevate the body’s level of cortisol and adrenaline.
Elevation of these hormones can interfere with the normal functioning of the parasympathetic nervous system resulting in overstimulation of the vagus nerve.
Vagus nerve induced palpitation is felt as a thud, a hollow fluttery sensation, or a skipped beat, depending on at what point during the heart’s normal rhythm the vagus nerve fires.
Frequently, anxiety and panic attacks in patients experiencing palpitations causes further anxiety and increased vagus nerve stimulation
The anxiety to palpitation link explains why many panic attacks involve the impending sense of cardiac arrest.
It is suggested that physical and mental distress may contribute to the occurrence of palpitations, possibly due to the depletion of micronutrients involved in maintaining healthy, psychological and physiological function.
The presence of gastrointestinal bloating, indigestion, and hiccoughs can stimulate the vagus nerve and cause palpitations due to branches of the vagus nerve innervating the G.I. tract, diaphragm, and lungs are present.
Many psychiatric conditions can result in palpitations: depression, generalized anxiety disorder, panic attacks, and somatization.
Metabolic conditions that can result in palpitations include: hyperthyroidism, hypoglycemia, hypocalcemia, hyperkalemia, hypokalemia, hypermagnesemia, hypomagnesemia, and pheochromocytoma.
The medications most likely to result in palpitations include sympathomimetic agents, anticholinergic drugs, vasodilators and withdrawal from beta blockers.
Common causes also include: excess caffeine, marijuana.
Cocaine, amphetamines, 3-4 methylenedioxymethamphetamine (Ecstasy or MDMA)
can also cause palpitations.
Palpitation sensations can arise from extra-systoles or tachyarrhythmia.
Palpitations are rarely noted due to bradycardia.
Palpitations appreciated as a brief flip-flopping in the chest, the palpitations are thought to be caused by extra- systoles such as supraventricular or ventricular premature contractions.
The flip-flop sensation is thought to result from the forceful contraction following the pause, and the sensation that the heart is stopped results from the pause.
The sensation of rapid fluttering in the chest may be a result from a sustained ventricular or supraventricular arrhythmia.
The sudden cessation of this rapid fluttering can suggest paroxysmal supraventricular tachycardia.
Irregular palpitations indicate atrial fibrillation as a source of the palpitations.
An irregular pounding sensation in the neck can be caused by the dissociation of mitral valve and tricuspid valve, and the subsequent atria are contracting against a closed tricuspid and mitral valves, thereby producing cannon A waves.
Palpitations induced by exercise could be suggestive of cardiomyopathy, ischemia or channelopathies.
Diagnosis:
Diagnostic clues are based on the
description of palpitation, approximate age of the person when first noticed and the circumstances under which they occur are important.
Information about caffeine intake and whether continual palpitations can be stopped by deep breathing or changing body positions is helpful.
How palpitations start and stop, abruptness or not, whether or not they are regular, and approximately how fast the pulse rate is during an attack.
History includes age of onset, symptoms including rhythm, situations that commonly result in the symptoms, mode of onset, duration of symptoms, factors that relieve symptoms, positions and other associated symptoms such as chest pain, lightheadedness or syncope.
History of all medications, including over-the-counter medications.
Social history, including exercise habits, caffeine consumption, alcohol and illicit drug use, should also be determined.
Past medical history and family history may provide indications to the etiology of the palpitations.
Palpitations since childhood are most likely caused by a supraventricular tachycardia.
Palpitations that first occur later in life are more likely to be secondary to structural heart disease.
A rapid regular rhythm is more likely to be secondary to paroxysmal supraventricular tachycardia or ventricular tachycardia.
Abrapid and irregular rhythm is more likely to be an indication of atrial fibrillation, atrial flutter, or tachycardia with variable block.
Supraventricular and ventricular tachycardia is thought to result in palpitations with abrupt onset and abrupt termination.
Terminating palpitations with a Valsalva maneuver indicates possibly a supraventricular tachycardia.
Palpitations associated with chest pain may suggest myocardial ischemia.
When lightheadedness or syncope accompanies palpitations, ventricular tachycardia, supraventricular tachycardia, or other arrhythmias should be considered.
ECG changes that are associated with specific disturbances of the heart rhythm may be noticed; thus physical examination and ECG remain important in the assessment of palpitation.
A complete physical exam should include vital signs (orthostatic as well), cardiac auscultation, lung auscultation, and examination of extremities.[
Positive orthostatic vital signs may indicate dehydration or an electrolyte abnormality.
A mid-systolic click and heart murmur may indicate mitral valve prolapse.
A holo-systolic murmur best heard at the left sternal border which increases with Valsalva may indicate hypertrophic obstructive cardiomyopathy.
An irregular rhythm indicates atrial fibrillation or atrial flutter.
Evidence of cardiomegaly and peripheral edema may indicate heart failure and ischemia or a valvular abnormality.
Tests of thyroid gland function, are important baseline investigations.
The diagnostic testing is usually 24-hour, or longer, ECG monitoring, using a recorder called a Holter monitor, which can record the ECG continuously during a 24-hour or 48-hour period.
There are three types of ambulatory EKG monitoring devices: Holter monitor, continuous-loop event recorder, and an implantable loop recorder.[
Then Zio Patch allows continuous recording for up to 14 days; the patient indicates when symptoms occur by pushing a button on the device and keeps a log of the events.
A continuous-loop event recorder monitors the ECG continuously, but only saves the data when the wearer activates it.
An implantable loop recorder may be helpful in people with very infrequent but disabling symptoms.
This recorder is implanted under the skin on the front of the chest, like a pacemaker, and the data examined using an external device that communicates with it by means of a radio signal.
The heart in most people with palpitation is completely normal in its physical structure.
Occasionally abnormalities such as valve problems may be present,detected by a murmur or echocardiography scan of the heart
A 12-lead electrocardiogram is performed on every patient complaining of palpitations.
The presence of a short PR interval and a delta wave, the Wolff-Parkinson-White syndrome, is an indication of the existence of ventricular pre-excitation.
Significant left ventricular hypertrophy with deep septal Q waves in I, L, and V4 through V6 may indicate hypertrophic obstructive cardiomyopathy.
The presence of Q waves may indicate a prior myocardial infarction as the etiology of the palpitations, and a prolonged QT interval may indicate the presence of the long QT syndrome.
Laboratory studies: Complete blood count can assess for anemia and infection.
Serum urea, creatinine and electrolytes to assess for electrolyte imbalances and renal dysfunction.
Thyroid function tests may demonstrate a hyperthyroid state.
In most patients benign conditions underly palpitations, and it is necessary to identify patients who are at higher risk for an arrhythmia.
Evaluation of palpitations.
Recommended laboratory studies include an investigation for anemia, hyperthyroidism and electrolyte abnormalities.
Echocardiograms are indicated for patients in whom structural heart disease is a concern.
Additional diagnostic testing is recommended for those with
suggestion of an arrhythmia, those who are at high risk for an arrhythmia, and those who remain anxious to have a specific explanation of their symptoms.
Those at high risk for an arrhythmia include: those with organic heart disease or any myocardial abnormality that may lead to serious arrhythmias:
a scar from myocardial infarction, idiopathic dilated cardiomyopathy, clinically significant valvular regurgitant, or stenotic lesions and hypertrophic cardiomyopathies.
Electrophysiology testing enables a detailed analysis of the underlying mechanism of the cardiac arrhythmia,and are usually indicated in those with a high pretest likelihood of a serious arrhythmia.
Treatment:
Treating palpitations depends on the severity and cause of the condition.
Radiofrequency ablation cures most types of supraventricular and many types of ventricular tachycardias.
Palpitations that are secondary to supraventricular or ventricular ectopy or associated with normal sinus rhythm are thought to be benign, and the management involves reassurance of the patient that these arrhythmias are not life-threatening: if symptoms are incapacitating, treatment with beta-blocking medications could be considered.
People who present to the emergency department who are asymptomatic, with unremarkable physical exams, have non-diagnostic EKGs and normal laboratory studies, can safely be discharged to home.
Patients whose palpitations are associated with syncope, uncontrolled arrhythmias, hemodynamic compromise, or angina are admitted for further evaluation.
Palpitation that is caused by vagus nerve stimulation rarely involves physical defects of the heart, and are extra-cardiac in nature.
Vagus nerve induced palpitations are not evidence of an unhealthy heart muscle.
Anxiety and stress are strongly associated with increased frequency and severity of vagus nerve induced palpitation.
Anxiety and stress reduction may reduce or eliminate symptoms of vagal nerve induced palpitations, temporarily.
Changing body position may also help reduce symptoms due to the vagus nerve’s innervation of several structures within the body such as the GI tract, diaphragm and lungs.