Heart Palpitations

Palpitations are a patient's subjective awareness of their own heartbeat — described variably as racing, pounding, fluttering, a flip-flop, or a skipped beat, felt in the chest, throat, or neck. Palpitations are a symptom, not a diagnosis, and the differential is genuinely broad: the same complaint can represent an entirely benign, self-limited sensation with an identifiable situational trigger, or a marker of a structural or electrical cardiac problem carrying real risk. Palpitations account for roughly 16% of visits to primary care and are the second leading reason for a cardiology referral, and affect approximately 10% of the population at some point in their lifetime, though they account for only a small minority of emergency department visits overall.^[1][2]

A landmark outpatient cohort found the underlying cause distributed roughly as follows^[1]:

These figures do not sum to 100% — a meaningful share of patients have a cause that is multifactorial, never definitively identified, or falls outside these broad categories — but the distribution makes an important point: the single most common category is psychiatric, and a genuinely dangerous ventricular arrhythmia is comparatively rare, yet it is precisely the rare-but-dangerous end of the spectrum that a structured history and a few targeted tests need to reliably screen for.

This chapter is deliberately scoped to the general, pharmacist-relevant palpitations triage and etiology framework — with genuine emphasis on the extensive list of drug- and substance-induced causes pharmacists are uniquely positioned to identify and act on. The platform's dedicated chapters on Atrial Fibrillation, Atrial Flutter, Supraventricular Tachycardia, Ventricular Tachyarrhythmias, Bradycardia, and Syncope each own the full mechanism, diagnostic, and treatment detail for their specific condition; this chapter references them rather than repeating their content, and instead focuses on recognizing when palpitations likely represent 1 of those conditions versus a benign, situational, or medication-related cause.

Cardiac arrhythmias — covered in depth by their own dedicated chapters

Non-arrhythmic cardiac causes

Mitral valve prolapse is the most common structural cause of palpitations, classically producing a mid-systolic click with or without a late systolic murmur.^[1] A harsher, more prominent murmur raises concern for a cardiomyopathy or another structural lesion and warrants echocardiography.

Non-cardiac causes — actually more common than most cardiac ones

• Anxiety and panic disorder is the single most common noncardiac etiology of palpitations, and the largest single category overall.^[1] A history of panic disorder itself is a genuinely reassuring finding statistically. That said, a cardiac cause coexists in up to 13% of patients whose presentation looks psychiatric — anxiety should be reached as a diagnosis after red flags and an organic cause are reasonably excluded, not assumed first because the presentation looks classic.^[1] See the dedicated Anxiety Disorders chapter.
• Hyperthyroidism — palpitations, often with tremor, heat intolerance, and weight loss — is a genuinely common and easily screened-for cause; see the dedicated Thyroid Disorders chapter.
• Anemia — a compensatory tachycardia and a forceful, easily perceived heartbeat; see the dedicated Iron Deficiency Anemia chapter and the platform's other anemia chapters for the specific type.
• Fever — a proportional tachycardia is physiologic and typically resolves as the fever is treated; see the dedicated Fever chapter.
• Hypoglycemia — an adrenergic surge (palpitations, sweating, tremor) in a patient on insulin or a sulfonylurea; see the dedicated Diabetes Mellitus chapter.
• Pregnancy — a physiologic rise in heart rate and stroke volume makes mild palpitations common and usually benign; see Special Populations.
• Pheochromocytoma — rare, but a classic cause of episodic palpitations with headache, diaphoresis, and paroxysmal hypertension, worth keeping on the list when episodes are severe and stereotyped.

Drug- and substance-induced causes — the pharmacist's central focus

Medications and substances account for a real minority of palpitations overall,^[1] but this is the category most directly actionable by a pharmacist, and the 1 most likely to be missed if not asked about explicitly.

The pharmacist's triage role: benign versus concerning pattern

A focused history can often distinguish a likely-benign presentation from 1 warranting urgent evaluation without any testing at all. Reassuring features include: brief duration (under 5 minutes, a pattern with a genuinely reassuring negative likelihood ratio),^[1] a clearly situational trigger the patient can identify (caffeine, stress, exercise, a new medication), no associated chest pain/dyspnea/syncope, and a normal cardiac exam. Concerning features — sustained episodes, exertional onset, an abnormal exam, or any of the red flags below — change the plan from reassurance to structured workup or urgent referral; see Red Flags & Refer.

• Known structural or ischemic heart disease.
• A family history of unexplained sudden cardiac death, particularly at a young age.
• A personal or family history of long QT syndrome or another inherited arrhythmia syndrome.
• Older age — a higher pretest probability of a true arrhythmia (especially atrial fibrillation) relative to a psychogenic cause.
• A history of anxiety or panic disorder — the single largest contributing category, though not a reason to skip screening for an organic cause.
• High caffeine, energy-drink, or stimulant intake, including prescribed ADHD medications.
• Polypharmacy that includes 2 or more QT-prolonging drugs, or any QT-prolonging drug combined with hypokalemia, hypomagnesemia, bradycardia, or hypothyroidism.
• Untreated or undertreated thyroid disease, anemia, or diabetes with a hypoglycemia risk.
• Pregnancy — a physiologic rise in heart rate and stroke volume.
• A recent new medication, OTC purchase, or dose change, especially a stimulant, decongestant, bronchodilator, thyroid hormone, or QT-prolonging agent.
• Illicit stimulant use or heavy alcohol use, including recent cessation (withdrawal).
• Female sex — somewhat more often represented in the psychogenic/anxiety category, though this should never substitute for an individual assessment.

Any patient meeting 1 or more of these criteria should be directed to urgent medical assessment (emergency department or an urgent cardiology referral, depending on severity and local pathways) rather than managed through a routine pharmacy medication review. See also the dedicated Syncope chapter when loss of consciousness is the presenting or accompanying complaint.

History

Ask the patient to describe the sensation in their own words — racing, pounding, fluttering, a skip, a flip-flop — and establish onset and offset (abrupt versus gradual), duration, frequency, and any identifiable trigger (caffeine, exercise, stress, a specific body position, a new medication). A sustained episode lasting more than 5 minutes, or 1 occurring at work or interfering with sleep, each carries a meaningfully higher likelihood ratio for a cardiac cause; a duration under 5 minutes and a history of panic disorder are each comparatively reassuring.^[1] A regular, rapid "pounding in the neck," especially one triggered by standing after bending forward, is a specific and high-yield description for AV nodal reentrant tachycardia.^[1] Take a complete medication, supplement, and substance history — prescription, OTC, herbal, caffeine/energy drinks, alcohol, and any illicit or recreational stimulant use — and ask directly whether the palpitations started or changed after a new medication, a dose change, or a new OTC purchase; this single question is frequently the highest-yield step available to a pharmacist. Ask about associated chest pain, dyspnea, syncope/near-syncope, and family history of sudden cardiac death or an inherited arrhythmia syndrome.

Physical examination

Check pulse rate and regularity (an irregularly irregular pulse suggests atrial fibrillation), auscultate for a murmur or click (a mid-systolic click with or without a late systolic murmur suggests mitral valve prolapse; a harsher murmur raises concern for structural disease),^[1] and look for signs of thyrotoxicosis (tremor, warm moist skin, lid lag) or anemia (pallor, tachycardia out of proportion to activity).

Electrocardiography

A resting 12-lead ECG is the key initial test whenever an arrhythmia is genuinely suspected, and is reasonable in most patients presenting with palpitations. Look specifically for a prolonged QT interval (raising concern for polymorphic ventricular tachycardia risk), a short PR interval or delta wave (suggesting a reentrant pathway), and significant nonspecific ST-segment changes, which have themselves been associated with increased arrhythmic death risk in older patients.^[1] A single normal resting ECG does not exclude an intermittent arrhythmia captured only during a symptomatic episode.

Ambulatory monitoring

For symptoms not captured on a single ECG, monitoring duration should match symptom frequency^[2]:

Laboratory testing

A thyroid-stimulating hormone (TSH) and a complete blood count (CBC) are genuinely high-yield, low-cost screens for 2 of the more common non-cardiac causes (thyroid dysfunction and anemia). Electrolytes (specifically potassium and magnesium) are important whenever a QT-prolonging drug is in the picture, and a point-of-care glucose is relevant when the pattern and medication list suggest hypoglycemia.

A structured, symptom-driven approach to testing

The classic teaching on palpitations evaluation emphasized directing testing toward the specific features the history and exam raise, rather than reflexively ordering every available cardiac test — a principle that remains sound today.^[5] Consistent with this, the American College of Cardiology's Choosing Wisely recommendation specifically advises against routine imaging stress testing or coronary CT angiography as an initial, routine investigation for palpitations or presyncope in a patient without another indication for advanced cardiac imaging.^[6]

Differential by presenting pattern

• Identify the underlying cause through a focused, efficient history, exam, and targeted testing, rather than reflexive broad investigation.
• Screen explicitly for red flags before attributing palpitations to a benign or situational cause.
• For the many benign or situational cases, provide genuine reassurance and trigger modification — not pharmacotherapy the patient does not need.
• For drug- or substance-induced palpitations, identify and adjust the causative agent in collaboration with the prescriber.
• Route a confirmed or strongly suspected arrhythmia to the platform's dedicated chapter for that specific condition rather than managing it as an undifferentiated palpitations problem.
• Identify and treat an underlying non-cardiac cause (anemia, thyroid dysfunction, hypoglycemia) when present.
• Avoid 2 opposite errors: reflexively over-testing a clearly benign, situational presentation, and reflexively reassuring a presentation that actually carries a red flag.
• Confirm the original indication for any adjusted medication remains adequately treated after the change.

Trigger-related (caffeine, stimulants, decongestants)

Preferred approach counsel on trigger avoidance or moderation — for caffeine, this means grounding the conversation in a specific number the patient can act on rather than a vague "cut back" (see Non-Pharmacologic Management).^[3] For an OTC decongestant, discuss a non-sympathomimetic alternative or simply stopping it once the acute indication has resolved.

ADHD medications, beta-agonist inhalers, thyroid hormone

Preferred approach a collaborative dose or timing review with the prescriber rather than a unilateral change — these are medications treating a real, ongoing condition, and under-treating that condition is its own genuine harm. For a beta-agonist inhaler specifically, confirm the patient is not simply overusing a reliever because the underlying asthma or COPD is poorly controlled — that is the actual problem to fix, not just the palpitations it produces. For thyroid hormone, recheck TSH before assuming the current dose is correct.

QT-prolonging drug combinations

Act promptly when new palpitations occur in a patient on 2 or more QT-prolonging drugs, or 1 such drug plus a risk factor (hypokalemia, hypomagnesemia, bradycardia, hypothyroidism) — obtain an ECG for a QTc measurement and review the full medication list for an avoidable combination, correcting any electrolyte abnormality found.^[4] See the dedicated Ventricular Tachyarrhythmias chapter for the full management of a confirmed prolonged QT interval.

Anticholinergics

Preferred approach for an OTC first-generation antihistamine or anticholinergic used for sleep, allergy, or bladder symptoms, discuss a lower-burden substitute with the prescriber where one is genuinely available, rather than continuing by default.

Withdrawal

Do not stop a chronically used beta-blocker abruptly — reinstate or use a structured taper. For alcohol withdrawal, manage per the dedicated Alcohol-Related Disorders chapter's symptom-triggered protocol rather than treating the palpitations as an isolated problem.

A confirmed or strongly suspected arrhythmia

Refer within the platform route atrial fibrillation/flutter, supraventricular tachycardia, ventricular arrhythmias, and bradyarrhythmia to their own dedicated chapters for full diagnostic confirmation and treatment — this chapter's role ends at recognizing the pattern and triaging appropriately.

An identified non-cardiac cause

Preferred approach treat the underlying condition (anemia, hyperthyroidism, hypoglycemia) per its own dedicated chapter; palpitations typically resolve as the underlying condition is corrected, without needing separate symptomatic therapy.

Benign, situational, or anxiety-related palpitations refractory to reassurance

Situational a low-dose beta-blocker can be a reasonable, time-limited option once red flags and a reversible cause have been genuinely excluded and reassurance alone has not been sufficient — see Pharmacologic Treatment Options and the dedicated Anxiety Disorders chapter for situational-anxiety-specific dosing.

Trigger avoidance and moderation

• Caffeine — ground the counselling conversation in a concrete number: Health Canada recommends a maximum daily caffeine intake of 400 mg for healthy adults, 300 mg for those who are pregnant, planning pregnancy, or breastfeeding, and 2.5 mg per kilogram of body weight for children and adolescents.^[3] Walking through a typical day's coffee, tea, energy drinks, and chocolate against this ceiling is often more actionable for a patient than a general instruction to "cut back," and frequently identifies the trigger directly.
• Reduce or eliminate other stimulant sources where they are not medically necessary — energy drinks, pre-workout supplements, and OTC decongestants used beyond their acute indication.
• Moderate alcohol intake, particularly in a patient whose palpitations correlate with drinking episodes ("holiday heart" pattern).
• Address poor sleep and significant stress, both genuine independent contributors to palpitations, particularly in the anxiety-related category.
• Maintain adequate hydration and electrolyte intake, especially in hot weather, with significant exercise, or with diarrhea/vomiting.
• For situational, predictable triggers (a specific stressful event, a performance situation), simple avoidance or a planned coping strategy is often sufficient without any medication.

Patient education

• Explain, in plain language, the specific mechanism identified — this alone measurably reduces anxiety about the sensation itself, particularly once a benign or reversible cause is confirmed.
• Never stop a prescribed medication on your own because of a suspicion it is causing palpitations — discuss it with the prescriber or pharmacist first, since some of the relevant drugs (beta-blockers, certain psychiatric medications) carry their own real risk from abrupt discontinuation.
• Keep a simple symptom diary (time, duration, activity, and any trigger) when the cause is not immediately obvious — this becomes genuinely useful data at the next review or when correlated against a wearable device recording.
• If using a smartwatch or smartphone-based heart-rhythm feature, bring the actual recording (not just a description) to the next appointment — a captured strip during a symptomatic episode is far more useful than a recollection.^[2]
• Know the specific red flags that warrant urgent care rather than waiting for the next scheduled visit (see Red Flags & Refer).
• Bring an updated medication list to every appointment, including any new OTC, supplement, or energy-drink/stimulant use.

Pregnancy

A physiologic rise in heart rate and stroke volume makes mild, brief palpitations common and usually benign in pregnancy. Still screen for the same organic causes (anemia — genuinely more common in pregnancy — and thyroid dysfunction) rather than attributing every case to pregnancy itself, and evaluate red flags exactly as in a non-pregnant patient. Avoid unnecessary medication changes for mild, non-red-flag palpitations; confirm any medication adjustment against the drug's own Drug Database entry and the relevant condition-specific chapter for pregnancy-specific guidance.

Older adults

A meaningfully higher pretest probability of a true arrhythmia — particularly atrial fibrillation — relative to a psychogenic cause, so maintain a lower threshold for ECG and, where indicated, ambulatory monitoring rather than defaulting to reassurance. Polypharmacy raises the odds of an inadvertent QT-prolonging drug combination; screen the full medication list specifically for this whenever palpitations are the presenting complaint.^[4]

Adolescents and young adults

Energy-drink and stimulant use (including illicit use) are disproportionately represented in this group, and the psychogenic/anxiety category remains large. Apply the age- and weight-based caffeine ceiling (2.5 mg/kg) specifically when counselling this group, since a single large energy drink can meaningfully exceed it.^[3]

Patients with known structural heart disease

The same palpitations that would be reassuring in a young, healthy patient carry materially more weight here — maintain a lower threshold for ECG and cardiology referral, and be especially cautious about adding any QT-prolonging drug or a new sympathomimetic agent without discussing it with the treating cardiologist.

Renal and hepatic impairment

Reduced clearance raises effective exposure to several of the relevant drugs without any dose change having been made — citalopram (reduce the maximum dose in hepatic impairment), domperidone (increased QT risk in renal/hepatic impairment), and methadone (reduced clearance in hepatic impairment) are the most directly relevant examples in this chapter's drug list. Confirm renal/hepatic dose adjustment specifically for these agents when palpitations are the presenting complaint.

Athletes

Physiologic sinus bradycardia and occasional benign ectopy are common in well-conditioned athletes and do not, by themselves, need treatment. Distinguishing this from a genuinely pathologic cause relies on the same red-flag screen as any other patient — exertional syncope or a family history of sudden cardiac death in an athlete warrants prompt cardiology evaluation, not reassurance based on fitness level alone.

After any medication adjustment made for suspected drug-induced palpitations, reassess within days to a couple of weeks to confirm the symptom has genuinely improved, and just as importantly, confirm the original indication for the adjusted drug remains adequately treated (asthma control after a reliever-use review, TSH still at target after a thyroid-dose change, ADHD symptoms still adequately managed after a stimulant-timing adjustment). For a patient started on ambulatory monitoring, confirm the device was actually worn for the intended duration and that any captured events were reviewed and communicated back to the patient.

Complications of unaddressed palpitations

• A missed arrhythmia — attributing palpitations to "probably anxiety" or "probably the coffee" without adequately screening for red flags risks missing a genuine atrial fibrillation (with its own embolic stroke risk), a ventricular arrhythmia, or a prolonged QT interval; drug/lifestyle causation and a genuine underlying arrhythmia are not mutually exclusive and both need to be actively considered.
• Progression to a dangerous rhythm — unaddressed cumulative QT-prolonging polypharmacy carries a real, if individually small, torsades de pointes risk that compounds with each additional agent or unaddressed electrolyte abnormality.^[4]
• Medication nonadherence — a patient who attributes palpitations to a needed drug (a stimulant, a thyroid medication, a bronchodilator) may simply stop taking it without telling anyone, leaving the original condition undertreated; a proactive medication review headed off before this happens is materially better than reacting after the fact.
• Unnecessary repeated testing and visits — a patient whose benign, situational cause is never clearly identified and explained may return repeatedly for reassurance or escalate to unnecessary advanced testing; a clear explanation and a concrete trigger-modification plan reduce this cycle.
• Ongoing anxiety and reduced quality of life — even genuinely benign palpitations can be distressing when unexplained; clear communication of a benign finding is itself a meaningful part of treatment.

1. If palpitations persist after removing an identified trigger or adjusting a suspected causative medication, first confirm the change was actually made and adhered to, and that enough time has passed for the drug (or a caffeine/stimulant source) to fully clear.
2. Re-screen the medication and substance list for a second, less obvious contributor — a single obvious suspect corrected in isolation is a common source of apparent treatment failure in a patient on multiple relevant substances.
3. If initial ambulatory monitoring did not capture an event, extend the monitoring duration or modality to match symptom frequency — an event monitor or wearable device for infrequent symptoms, or an implantable loop recorder for infrequent but genuinely concerning episodes.{C(gauer)}
4. If a specific arrhythmia is now identified (atrial fibrillation/flutter, supraventricular tachycardia, a ventricular arrhythmia, or bradyarrhythmia), move to that dedicated chapter for full management rather than continuing a general palpitations workup.
5. If red flags remain absent, the workup remains negative, and symptoms persist, reconsider or revisit the anxiety/panic disorder pathway specifically — including a referral for cognitive behavioural therapy per the dedicated Anxiety Disorders chapter — now with the reassurance of a genuinely completed organic workup behind it.
6. For persistent, distressing, reassurance-refractory benign palpitations with no identified cause after a thorough workup, a trial of a low-dose beta-blocker (see Pharmacologic Treatment Options) or referral to cardiology/electrophysiology for further evaluation are both reasonable next steps.

• Attributing all palpitations to anxiety or stress without first screening for red flags and an organic or drug-induced cause — a cardiac cause coexists in a meaningful minority of patients whose presentation looks psychiatric.
• Not asking specifically about caffeine, energy drinks, OTC decongestants, supplements, and illicit or recreational stimulant use — patients reliably under-report these unless asked directly.
• Ordering advanced cardiac imaging (stress testing, coronary CT angiography) reflexively for palpitations without another indication, rather than following a structured, symptom-driven approach to testing.
• Assuming a single normal resting ECG excludes an intermittent arrhythmia.
• Missing hypoglycemia as a cause in a patient on insulin or a sulfonylurea because the presentation looks like ordinary palpitations rather than a classic hypoglycemic episode.
• Underestimating cumulative QT-prolonging polypharmacy risk by evaluating each drug in isolation rather than screening the whole medication list together.
• Stopping a beta-blocker, a psychiatric medication, or another chronically used drug abruptly based on a suspicion it is causing palpitations, without prescriber involvement or a taper plan.
• Not checking TSH and a CBC — 2 genuinely high-yield, low-cost screens frequently skipped in a routine palpitations workup.
• Treating a captured wearable-device reading as a stand-alone diagnosis rather than correlating it with symptoms and confirming with a standard ECG.
• Managing a confirmed arrhythmia (atrial fibrillation, SVT, a ventricular arrhythmia, bradycardia) as an undifferentiated palpitations problem instead of moving to that condition's own dedicated, more complete chapter.

How to use this table: this catalogues medications and substances commonly implicated in palpitations, organized by the 4 mechanisms discussed in Recognize the Condition, to support a structured medication review — it is not a treatment menu. Doses shown are typical adult doses only and require patient-specific confirmation, including renal/hepatic adjustment. Select any drug name to open its complete Pharmasist Drug Database page.

Mechanism 1 — Stimulants: Caffeine, Decongestants, ADHD Medications, Illicit Stimulants

Ask about every source explicitly — OTC, herbal/energy-product, and illicit — since patients rarely volunteer these unprompted.

Mechanism 2 — Beta-Agonist Bronchodilators

Overuse of a reliever beyond the prescribed frequency itself signals poorly controlled asthma/COPD needing reassessment.

Mechanism 3 — QT-Prolonging Drugs (Distinct Mechanism)

Risk rises sharply when 2 or more of these are combined, or when hypokalemia, hypomagnesemia, bradycardia, or hypothyroidism coexist. See the Ventricular Tachyarrhythmias chapter for full QT-interval management.

Mechanism 4 — Anticholinergics, Thyroid Hormone, and Withdrawal

Ask about OTC anticholinergic/antihistamine use explicitly, and never stop a chronically used beta-blocker abruptly.