What could be causing my frequent heart palpitations?

What Could Be Causing Your Frequent Heart Palpitations?

Your sensation of skipped heartbeats is most likely caused by premature atrial contractions (PACs) or premature ventricular contractions (PVCs), which occur in nearly all individuals and are typically benign, though they require evaluation to exclude underlying cardiac disease. 1

Understanding Your Symptoms

The sensation of "skipped beats" is commonly described as pauses or irregularities in heart rhythm, often followed by a strong heartbeat. 2 This pattern is characteristic of premature beats rather than sustained arrhythmias. 2

Key distinguishing features you should identify:

• Pattern of onset: Does your heart suddenly start racing and then suddenly stop (suggests AVNRT or AVRT), or does it gradually speed up and slow down (suggests sinus tachycardia or anxiety)? 3, 4
• Regularity: Are the palpitations regular or irregular? Irregular palpitations suggest premature beats or atrial fibrillation, while regular rapid palpitations suggest supraventricular or ventricular tachycardia. 3, 4
• Triggers: Do they occur with caffeine, alcohol, stress, or specific positions like sitting? 3, 4

Most Common Causes

Benign Premature Contractions

Premature atrial contractions (PACs) occur in nearly all individuals and are the most common cause of palpitations. 1 While previously considered completely benign, frequent PACs are now recognized as associated with developing atrial fibrillation. 1 Premature ventricular contractions (PVCs) occur in more than two-thirds of the population and typically cause the sensation of skipped beats. 1

Sinus Tachycardia

Sinus tachycardia (heart rate >100 bpm) is an appropriate physiologic response to stress, fever, dehydration, anemia, hyperthyroidism, or medications. 2 It accelerates and terminates gradually, unlike paroxysmal arrhythmias. 2, 3

Supraventricular Tachycardia

If your palpitations have sudden onset and termination with a regular rapid rhythm, this suggests AVNRT or AVRT, particularly in younger patients. 2, 3 Approximately 15% of patients with SVT experience syncope. 2, 3

Immediate Evaluation Required

You need a 12-lead ECG immediately to identify the rhythm and look for pre-excitation patterns. 3 This is the single most important first step.

Seek emergency care immediately if you experience:

• Syncope or near-syncope with palpitations 3, 4
• Chest pain or pressure 3, 4
• Severe shortness of breath 3, 4
• Palpitations during physical exertion 3, 4

Diagnostic Workup

Initial Assessment

• 12-lead ECG: Essential first test to identify rhythm abnormalities and pre-excitation patterns 3
• Orthostatic vital signs: Measure blood pressure and heart rate lying down and after standing for 3 minutes (or 10 minutes if postural orthostatic tachycardia syndrome is suspected) 4
• Thyroid function tests: Hyperthyroidism is a common non-cardiac cause that must be excluded 4

Ambulatory Monitoring Strategy

For daily palpitations: 24-48 hour Holter monitoring 3

For symptoms several times per week: Event or loop recorders have superior diagnostic yield and are more cost-effective than Holter monitoring 3

For symptoms less than twice monthly with severe features: Consider an implantable loop recorder 3, 4

The critical principle: monitoring must continue until symptoms occur while wearing the device—non-diagnostic monitoring should not be considered conclusive. 3

When to Order Echocardiography

Echocardiography is indicated when: 3

• Sustained SVT is documented
• Abnormal ECG or physical examination findings
• Clinical suspicion of structural heart disease (valvular disease, cardiomyopathy)
• Frequent PVCs (>10,000 per day or ≥2,000 per 24 hours) 2, 4

Among athletes with ≥2,000 PVCs per 24 hours, up to 30% were found to have underlying structural heart disease. 2

Exercise Stress Testing

Consider exercise testing if: 3, 4

• Palpitations are clearly triggered by exertion
• Concern for ischemia-induced arrhythmia exists
• Need to assess if PVCs suppress with exercise (favorable prognostic sign) 2

Reversible Causes to Exclude

Before attributing palpitations to a primary cardiac arrhythmia, systematically exclude: 3, 4

• Medications and substances: Caffeine, alcohol, nicotine, stimulants, over-the-counter decongestants, recreational drugs
• Metabolic causes: Hyperthyroidism, electrolyte abnormalities (particularly potassium), anemia
• Physiologic stressors: Fever, infection, dehydration
• Cardiac causes: Ischemia, structural heart disease, heart failure

Management Approach

For Benign Premature Contractions (PACs/PVCs)

First-line management involves lifestyle modifications: 4

• Eliminate caffeine, alcohol, and nicotine 3
• Ensure adequate hydration 4
• Manage stress and anxiety
• Review all medications for potential triggers 4

If lifestyle modifications are insufficient and symptoms are bothersome: Beta-blockers provide symptomatic relief 4, 1 Beta-blockers may be prescribed empirically after excluding significant bradycardia (<50 bpm). 3, 5

Critical Medication Safety

Never start Class I or III antiarrhythmic drugs without documented arrhythmia due to significant proarrhythmic risk. 3 This is a common and dangerous pitfall.

When Specialist Referral Is Mandatory

Immediate referral to cardiac electrophysiology is required for: 3

• Wolff-Parkinson-White syndrome (pre-excitation pattern) due to risk of sudden death
• Wide complex tachycardia documented on any rhythm strip
• Severe symptoms during palpitations (syncope, severe dyspnea)
• Pre-excitation with irregular palpitations (suggests atrial fibrillation with accessory pathway)

Consider referral for: 3

• Documented SVT despite normal structural evaluation (catheter ablation has high success rate with <5% recurrence and <1% risk of heart block) 3
• Drug resistance or intolerance
• Patient preference to avoid lifelong medication

Special Considerations

Postural Orthostatic Tachycardia Syndrome (POTS)

If palpitations occur predominantly while sitting or upon standing, particularly in young women, consider POTS (excessive heart rate increase >30 bpm or >120 bpm within 10 minutes of standing). 4 Management includes increased salt and fluid intake, physical reconditioning with gradual exercise, compression stockings, and midodrine for refractory symptoms. 4

High-Risk Features Requiring Urgent Evaluation

Ventricular rates <150 bpm with instability suggest the tachycardia is secondary to an underlying condition rather than the primary cause. 2 However, with ventricular dysfunction, even lower rates can cause symptoms. 2

Ventricular couplets, triplets, and non-sustained ventricular tachycardia always require investigation as they can be markers for underlying cardiac pathology. 2 Evaluation should include thorough family history, echocardiogram, cardiac MRI to assess for cardiomyopathies, ambulatory ECG monitor, and exercise ECG test. 2

Common Pitfalls to Avoid

• Do not rely on automatic ECG analysis systems—they are unreliable and commonly suggest incorrect diagnoses 3
• Do not dismiss syncope with palpitations—this warrants urgent evaluation 3
• Do not order comprehensive laboratory panels routinely—focus on thyroid function and electrolytes based on clinical suspicion 3
• Do not stop monitoring after non-diagnostic results—continue until symptoms are captured 3