Heart palpitations are among the most common symptoms that bring people to their doctor — and among the most anxiety-provoking, because the sensation of an abnormal heartbeat triggers immediate concern about cardiac disease. The clinical reality is more nuanced: approximately 40 to 50 percent of palpitations are caused by benign ectopic beats that pose no structural or arrhythmic risk. But 15 to 25 percent reflect cardiac arrhythmias that warrant evaluation and sometimes treatment. Understanding the spectrum of causes — and which warning signs indicate a more serious problem — helps patients and physicians approach palpitations appropriately.
What Are Heart Palpitations?
Palpitations are the uncomfortable awareness of one’s own heartbeat. They may be described as fluttering, pounding, racing, skipping, flipping, or thumping in the chest, throat, or neck. Not all palpitations involve a fast heart rate — patients may notice an irregular beat, a particularly strong beat following a pause, or a slow but forceful rhythm. The character of the sensation provides important diagnostic information: how the palpitation starts (suddenly or gradually), how it ends (abruptly or gradually), its duration, its rate (fast vs. normal), its regularity (regular vs. irregular), and whether it is associated with other symptoms like dizziness, chest pain, or shortness of breath.
The circumstances surrounding palpitations matter as well. Palpitations that occur during exertion, in a patient with known heart disease, or alongside syncope carry a very different clinical weight than palpitations that occur at rest in a young healthy person after drinking three cups of coffee. A careful history often points toward the likely cause before any test is ordered.
Benign Ectopic Beats: PACs and PVCs
The most common cause of palpitations is benign ectopic beats — premature cardiac contractions that arise from locations outside the normal cardiac conduction system.
Premature atrial contractions (PACs) arise from ectopic foci in the atrial myocardium and fire before the expected sinus beat. On ECG, they produce a premature narrow-complex QRS preceded by an abnormal P wave, often followed by a compensatory pause. The sensation patients describe is typically a “skipped beat” — though what is actually felt is the compensatory pause after the PAC, followed by the next stronger-than-usual sinus beat filling a ventricle that had slightly more time to fill. Common triggers include caffeine, alcohol, fatigue, stress, and stimulant medications.
PACs are benign in most individuals. However, frequent PACs — defined as more than 500 per 24 hours or a burden greater than 1 percent on ambulatory monitoring — are associated with an increased risk of developing atrial fibrillation. Patients with frequent PACs may warrant echocardiographic assessment and closer follow-up.
Premature ventricular contractions (PVCs) arise from ectopic foci in the ventricular myocardium. They appear on ECG as wide QRS complexes (greater than 120 milliseconds) with discordant T waves, preceding the expected beat. The sensation is often a more prominent “thud” or “flip” than a PAC — reflecting the strong compensatory sinus beat that follows the post-PVC pause and the fully filled ventricle. Approximately 70 percent of adults will have occasional PVCs detectable on prolonged monitoring.
PVCs are generally benign in structurally normal hearts. The clinical concern arises when PVC burden becomes high. A PVC burden above 10,000 beats per 24 hours, or above 10 to 15 percent of total beats, can cause PVC-induced cardiomyopathy — a reversible reduction in left ventricular ejection fraction that improves or resolves when the PVCs are suppressed. Catheter ablation of the ectopic PVC focus is highly effective in this setting, with success rates above 80 percent. PVCs that worsen during exercise — particularly in patients with structural heart disease — or that trigger runs of ventricular tachycardia require more urgent evaluation.
Atrial Fibrillation as a Cause of Palpitations
Atrial fibrillation is the most clinically significant arrhythmia that presents as palpitations. AF produces irregular, chaotic ventricular activation from multiple wandering reentrant circuits in the atria — generating ventricular rates that are typically 100 to 180 beats per minute when uncontrolled. Patients describe the palpitations as irregular, rapid, and chaotic — “fluttery” or “like a bag of worms in the chest” — distinct from the regular racing of SVT.
The importance of AF extends far beyond the palpitation symptom. AF increases stroke risk five-fold by promoting thrombus formation in the left atrial appendage; anticoagulation — not antiplatelet therapy — is required to reduce this risk. Persistent rapid AF can cause AF-induced cardiomyopathy: prolonged tachycardia impairs LV function in a reversible way that recovers with rate or rhythm control. New-onset AF presenting as palpitations should be evaluated urgently — not because the palpitations themselves are dangerous in the short term, but because the stroke and cardiomyopathy risks demand prompt assessment and treatment initiation.
Alcohol is a well-documented trigger of AF episodes — a phenomenon known as “holiday heart syndrome,” first described in patients presenting with AF after binge drinking, particularly during holiday periods. Even moderate alcohol consumption has been shown to increase AF risk in population studies.
SVT: Supraventricular Tachycardia
Supraventricular tachycardia (SVT) — most commonly atrioventricular nodal reentrant tachycardia (AVNRT) or atrioventricular reentrant tachycardia (AVRT) involving an accessory pathway — is one of the most characteristic palpitation presentations. The hallmark is abrupt onset: the heart rate switches from normal to 150 to 250 beats per minute in one beat, with equally abrupt termination. Patients describe it as “a switch being flipped” or “a light going on and off.”
In AVNRT — the most common SVT subtype — the reentrant circuit uses both the fast and slow pathways within the AV node simultaneously. This causes the atria to activate simultaneously with or just after the ventricles, producing cannon A waves in the jugular venous pulse — a visible neck pulsation that some patients notice alongside the palpitations.
SVT can sometimes be terminated with vagal maneuvers. The modified Valsalva maneuver — bearing down for 15 seconds while supine, then lying flat with legs raised — terminates SVT in approximately 40 to 50 percent of episodes. Adenosine, administered intravenously in monitored settings, terminates SVT by transiently blocking AV nodal conduction. Long-term, catheter ablation of the accessory pathway or slow AV nodal pathway is curative in 95 percent or more of cases — a permanent solution that eliminates a source of recurrent palpitations without lifelong medication.
Atrial flutter — a more organized atrial circuit firing at 250 to 350 beats per minute with typical 2:1 AV conduction — produces regular palpitations at a ventricular rate of approximately 150 beats per minute. Flutter shares many management considerations with AF, including stroke risk and rate/rhythm control strategies.
Ventricular Arrhythmias
Non-sustained ventricular tachycardia (NSVT) — three or more consecutive PVCs at a rate above 100 beats per minute, terminating spontaneously within 30 seconds — produces brief episodes of rapid palpitations that stop abruptly. In patients with structurally normal hearts, NSVT is generally benign. In patients with prior MI, structural cardiomyopathy, or inherited arrhythmia syndromes, NSVT is a red flag warranting further evaluation, because it may indicate a substrate for sustained VT or ventricular fibrillation.
Bigeminy — a pattern of alternating normal beat and PVC — produces an every-other-beat irregularity that some patients find extremely disturbing, feeling like the heart is constantly skipping. Trigeminy (normal-normal-PVC pattern) produces a similar irregular sensation. These patterns are almost always benign in structurally normal hearts but may require treatment if the PVC burden is high enough to cause cardiomyopathy.
Non-Cardiac Medical Causes
Several systemic conditions produce palpitations through non-arrhythmic mechanisms:
Hyperthyroidism — elevated thyroid hormone levels — causes sinus tachycardia and significantly increases the risk of atrial fibrillation. It is one of the most important reversible causes of palpitations and AF, detectable by checking TSH. Patients may also experience weight loss, heat intolerance, tremor, and anxiety alongside the palpitations.
Anemia reduces oxygen-carrying capacity, triggering compensatory sinus tachycardia as the heart attempts to maintain oxygen delivery through increased cardiac output. The palpitations are typically exertional, accompanied by fatigue and pallor. A complete blood count identifies the diagnosis.
Hypoglycemia triggers an adrenergic response — epinephrine release causes sinus tachycardia, diaphoresis, tremor, and palpitations. Diabetic patients on insulin or sulfonylureas are most at risk; the symptoms resolve with glucose correction.
Pheochromocytoma is a rare but important cause of episodic palpitations — classically presenting with the triad of episodic headache, diaphoresis, and palpitations, accompanied by hypertensive crisis. It is diagnosed by 24-hour urinary catecholamines and metanephrines.
Electrolyte abnormalities — particularly hypokalemia and hypomagnesemia — lower the threshold for cardiac ectopy and arrhythmia, increasing PAC and PVC frequency and raising AF and VT risk. Low potassium prolongs the QT interval and predisposes to torsades de pointes.
Medications and Substances
Caffeine is the most widely consumed stimulant and a common palpitation trigger, increasing cardiac ectopy at high doses in caffeine-sensitive individuals — though moderate caffeine consumption is not associated with increased arrhythmia risk in population studies. Alcohol can trigger AF even in otherwise healthy individuals at moderate-to-high doses — the holiday heart phenomenon. Beta-agonist inhalers (albuterol) cause dose-dependent sinus tachycardia and palpitations. Decongestants containing pseudoephedrine or phenylephrine have sympathomimetic effects that produce palpitations. Energy drinks combining high caffeine, taurine, and other stimulants have been associated with AF and VT in case reports.
QT-prolonging medications are particularly important: a long list of commonly used drugs — including azithromycin and other macrolide antibiotics, fluoroquinolones, antipsychotics (haloperidol, quetiapine), antiemetics (ondansetron, metoclopramide), and antiarrhythmics — prolong the QT interval. In susceptible individuals or in drug combinations, a prolonged QT can trigger torsades de pointes, a polymorphic VT that produces sustained rapid palpitations and may cause syncope or cardiac arrest.
Anxiety and Palpitations
Anxiety disorders and panic disorder are among the most common causes of palpitations, producing sinus tachycardia plus heightened awareness and sensitivity to the heartbeat. Patients with anxiety may notice and report as palpitations heartbeats that other people would not consciously perceive. Panic attacks produce particularly severe palpitations accompanied by chest tightness, dyspnea, tingling, dizziness, and an overwhelming sense of impending doom.
Anxiety-related palpitations are a diagnosis of exclusion — cardiac causes must be excluded appropriately before attributing palpitations to anxiety. Importantly, a history of anxiety or panic disorder does not protect against co-occurring cardiac arrhythmia. Many patients with paroxysmal AF or SVT have been told for years that their episodes are anxiety-related before an ambulatory monitor finally captures the true arrhythmia.
Warning Signs That Require Urgent Evaluation
Seek prompt medical evaluation for palpitations that are accompanied by any of the following:
- Syncope (fainting) or presyncope (near-fainting)
- Chest pain or pressure during or after the palpitation episode
- Occurrence during physical exertion
- Sustained duration of more than a few minutes
- A heart rate sensation above 150 beats per minute
- Known structural heart disease (prior MI, heart failure, valve disease)
- Family history of sudden cardiac death before age 50
- Current use of QT-prolonging medications
- Associated shortness of breath, diaphoresis, or hemodynamic instability
These red flags shift palpitations from a routine outpatient complaint to an urgent evaluation that may require same-day cardiology assessment or emergency department evaluation depending on severity.
How Palpitations Are Evaluated
The evaluation begins with a 12-lead ECG — identifying arrhythmias, pre-excitation (WPW), long QT, LVH, and prior MI. Laboratory tests include TSH (thyroid function), CBC (anemia), and a basic metabolic panel (electrolytes, including potassium and magnesium). An echocardiogram evaluates for structural heart disease and left ventricular function. Ambulatory monitoring is essential when palpitations are symptomatic but intermittent: a 24 to 48-hour Holter monitor for frequent episodes, a 30-day event recorder for less frequent symptoms. An exercise stress test evaluates palpitations that occur during exertion and can unmask exercise-induced VT or catecholaminergic polymorphic VT (CPVT).
For understanding the heart rate context of palpitations, see our article on what resting heart rate means. For the cardiovascular numbers relevant to overall cardiac health assessment, see heart health numbers every adult should know. For blood pressure changes that may accompany palpitations, see our article on what blood pressure is.
The American Heart Association provides patient resources on heart rhythm problems and palpitations. The NIH National Heart, Lung, and Blood Institute explains the evaluation and management of palpitations and arrhythmia. The CDC provides epidemiological data on arrhythmia prevalence and outcomes.
Most palpitations are benign — but “most” is not “all,” and the minority that reflect serious arrhythmia or structural disease require timely evaluation and treatment. The warning signs exist precisely to separate the benign majority from the important minority. When they are present, prompt evaluation is warranted. When they are absent and the workup is reassuring, the patient can be confidently reassured — and the search for lifestyle triggers can begin.
Bradyarrhythmias and Palpitations
While palpitations are commonly associated with fast or irregular rhythms, bradyarrhythmias — abnormally slow heart rhythms — can also cause a palpitation-like sensation. Patients with sick sinus syndrome experience alternating periods of inappropriately slow rates and breakthrough tachycardia episodes — a pattern called tachy-brady syndrome — which produces awareness of both the slow pauses and the sudden rapid beats. Complete heart block, where the atria and ventricles beat independently, produces forceful, widely spaced beats that some patients perceive as striking or thumping palpitations. Pacemaker therapy is the definitive treatment for symptomatic bradyarrhythmias causing these symptoms.
Pauses — whether from sick sinus syndrome, high-grade AV block, or post-PAC compensatory pauses — are often felt as particularly dramatic “dropped beats.” The cardiac output during a pause momentarily falls, followed by a compensatory increase as the next beat fills a fully loaded ventricle and ejects with greater force. This sequence — pause, then strong beat — is one of the most common palpitation patterns and one of the most reliably benign when the underlying cause is isolated ectopy in an otherwise normal heart.
Living With Recurrent Palpitations
For patients whose workup is negative and whose palpitations are attributed to benign ectopy or anxiety, management focuses on identifying and reducing triggers rather than medical suppression. Reduction or elimination of caffeine — coffee, tea, energy drinks, and cola — reduces PAC and PVC frequency in a significant subset of caffeine-sensitive individuals. Limiting or eliminating alcohol, particularly binge drinking episodes, reduces the risk of holiday heart AF episodes. Adequate sleep, stress management, and regular moderate aerobic exercise all reduce the sympathetic tone that drives ectopy frequency.
Magnesium supplementation — even in patients without overt hypomagnesemia — has been reported anecdotally to reduce PVC frequency, though evidence from controlled trials is limited. Potassium optimization is important in patients with borderline-low levels, as hypokalemia significantly increases ectopy. Avoiding decongestants, checking all medications for sympathomimetic effects, and minimizing over-the-counter stimulants are practical steps that often reduce symptom frequency without any prescription intervention.
For patients with confirmed arrhythmias, treatment options have expanded significantly. Beta-blockers and calcium channel blockers provide rate control and symptom suppression for SVT, AF, and PVC-related palpitations. Antiarrhythmic medications (flecainide, propafenone, sotalol, amiodarone) are reserved for more symptomatic or higher-risk arrhythmias. Catheter ablation — now a minimally invasive outpatient procedure — offers curative or near-curative outcomes for SVT (95%+ success), typical atrial flutter (95%+ success), and PVC-cardiomyopathy (80%+ success), and is increasingly used for AF rhythm control as a first-line option in younger patients.
Frequently Asked Questions About Heart Palpitations
Can palpitations occur in a healthy heart with no cause found?
Yes. A significant proportion of patients undergoing full evaluation — including ECG, Holter monitoring, and echocardiogram — have no identifiable arrhythmia or structural cause. In these cases, palpitations are often attributed to heightened body awareness, anxiety, or subclinical PACs/PVCs that were not captured during monitoring. Reassurance, lifestyle modification, and repeat monitoring if symptoms change are appropriate management strategies.
How long is too long for a palpitation episode?
Episodes that last more than a few minutes, particularly if accompanied by any associated symptoms (dizziness, chest pain, dyspnea), warrant urgent evaluation. Brief episodes — seconds to a minute or two — that terminate spontaneously and leave no residual symptoms are more likely to reflect benign ectopy or a brief SVT run. The key factors are not just duration but severity, associated symptoms, and the clinical context of the patient.
Should I go to the emergency department for palpitations?
Palpitations with syncope, chest pain, severe dyspnea, or a sense of hemodynamic instability (near-fainting, weakness, pallor, diaphoresis) warrant emergency evaluation. Palpitations that are ongoing at the time of evaluation — allowing real-time rhythm capture — are also worth urgent assessment even without severe associated symptoms. Palpitations that have resolved by the time care could be sought, in a patient with no red flag features and no significant cardiac history, can typically be evaluated in an outpatient setting.
Can exercise cause palpitations?
Exercise normally causes sinus tachycardia — an appropriate increase in heart rate — which some people perceive as palpitations. Exertional palpitations that represent a true arrhythmia, however, are a red flag that requires evaluation. Arrhythmias that worsen or are triggered by exercise — exercise-induced VT, catecholaminergic polymorphic VT, AF triggered by increased sympathetic tone — are more likely to represent significant underlying pathology than palpitations at rest. An exercise stress test is the appropriate initial test for exertional palpitation complaints.
When Palpitations Are Investigated With Implantable Monitors
For patients with infrequent but significant palpitation episodes that cannot be captured on standard ambulatory monitors, an implantable loop recorder (ILR) — a small subcutaneous device inserted under local anesthesia — provides continuous cardiac rhythm monitoring for up to three years. ILRs are particularly valuable when episodes are rare (once monthly or less), when prior monitoring has been unrevealing, or when the suspected arrhythmia could have serious consequences — such as suspected paroxysmal AF in a cryptogenic stroke patient, or unexplained syncope with palpitation preceding the event. The device automatically records and stores arrhythmias that meet programmed detection criteria, and patients can also manually trigger recordings during symptoms. This technology has transformed the evaluation of infrequent but potentially dangerous palpitation events by providing diagnostic clarity that short-term monitors simply cannot offer.
The key takeaway for patients experiencing palpitations is that context matters enormously. A healthy 25-year-old with occasional brief palpitations after coffee requires different evaluation — and carries a different prognosis — than a 65-year-old with heart failure experiencing regular rapid palpitations at rest. The evaluation pathway, the urgency of workup, and the significance of findings all depend on integrating the symptom character with the clinical context. When red flag features are absent and evaluation is reassuring, most palpitations represent benign electrical “noise” in a normal heart — not a sign of impending cardiac catastrophe. With appropriate evaluation and lifestyle attention, most patients with palpitations can be accurately diagnosed, appropriately reassured, and effectively managed.