Understanding Palpitations: A Focus on PSVT

Introduction

Palpitations are sensations of an unusually fast or forceful heartbeat that can be distressing to those who experience them. They may result from various causes, including anxiety, caffeine intake, or certain underlying heart conditions. Palpitations are a common reason for healthcare visits, with studies estimating that 15% to 30% of the general population may experience them at some point [1]. Patients often describe these sensations as racing, fluttering, or pounding heartbeats. One significant cause of palpitations is Paroxysmal Supraventricular Tachycardia (PSVT)—a condition marked by intermittent episodes of rapid heart rate originating above the ventricles [2]. The term "paroxysmal" highlights the sudden and brief nature of these episodes.

What is PSVT?

Paroxysmal Supraventricular Tachycardia (PSVT) is a type of arrhythmia characterized by episodes of rapid heart rate with a regular rhythm. These episodes begin and end abruptly and are typically not associated with structural heart disease.

It is categorized as a narrow complex supraventricular tachycardia, typically seen in healthy individuals without underlying cardiac abnormalities.

• Incidence: Approximately 2.5 per 1000 individuals in the general population.

  
  

Diagnosis of PSVT

PSVT is often diagnosed with a 12-lead ECG, which shows:

• A narrow QRS complex

• Rapid heart rate

• Short and regular R-R intervals

• Absence of identifiable P waves

In patients with underlying bundle branch block, PSVT may appear as a broad complex tachycardia.

However, the limitation of the standard ECG is its short duration (10 seconds), which may not capture self-terminating episodes. In such cases, Holter monitoring—which records ECG continuously over 24 hours, 48 hours, or up to 2 weeks—can be useful.

Symptoms of PSVT

• Primary Symptom: Palpitations (rapid, strong, or fluttering heartbeat)

• Other Symptoms:

  • Shortness of breath (SOB)

  • Dizziness

  • Syncope (fainting)

• Non-cardiac Symptoms:

  • Tinnitus

  • Burping

  • Chills

  • Sweating

  • Panic attacks

  • Asthma-like symptoms

Trigger Factors for PSVT

Lifestyle Factors:

• Excessive alcohol or caffeine consumption

• High-fat, high-sugar, or high-carbohydrate diets

• Smoking

• Dehydration

• Fatigue

• Lack of sleep

Medical Conditions:

• Anemia

• Hyperthyroidism

• Hypertension

• Coronary artery disease

• Connective tissue disorders

Hereditary Factors:

• Wolff-Parkinson-White (WPW) Syndrome is a major hereditary cause.

• Other genetic mutations are being explored, especially in AVNRT.

Types of PSVT

1. AVNRT (Atrioventricular Nodal Re-entrant Tachycardia):

• Most common type (~60% of PSVT cases)

• Involves re-entry circuits within the AV node using fast and slow pathways.

2. AVRT (Atrioventricular Re-entrant Tachycardia):

• Involves a macro-re-entry circuit using atria and ventricles.

• Subtypes:

  • Orthodromic AVRT: Impulse travels down AV node and returns via accessory pathway [3].

  • Antidromic AVRT: Impulse travels down accessory pathway and returns via AV node.

• Can be triggered by premature atrial or ventricular complexes [3].

3. Focal Atrial Tachycardia:

• A rarer form of PSVT

• Often associated with structural heart disease or connective tissue disorders (e.g., Rheumatoid Arthritis, Systemic Lupus Erythematosus) [3].

  
  

Management Strategies for PSVT

Initial Management:

• Vagal manoeuvres such as:

  • Valsalva manoeuvre

  • Carotid sinus massage

  • Success rate ranges from 5% to 43%

Pharmacological Management:

• Adenosine (first-line):

  • Rapid onset and short half-life

  • Administer IV bolus followed by saline flush

• Calcium Channel Blockers (e.g., Diltiazem):

  • Administer slowly with dilution

Emergency Management:

• If the patient is hemodynamically unstable, immediate DC cardioversion is required.

Long-Term Management:

• Electrophysiological Study (EPS):

  • Recommended for patients with frequent or symptomatic episodes

  • Helps identify re-entry circuits

  • Catheter ablation can be performed for definitive treatment

Case Presentation

A 44-year-old male, chronic alcoholic, presented with sudden-onset palpitations after drinking heavily for one week. He was anxious and restless.

• ECG Findings: Narrow complex tachycardia, absent P waves, and short R-R intervals—suggestive of PSVT (See Figure 1).

• Treatment: Administered Adenosine 6 mg IV bolus, followed by a 20 ml saline flush.

• Outcome: Successfully converted to normal sinus rhythm.

Figure 1. ECG Findings: Narrow complex tachycardia with absent P waves and short R-R intervals, suggestive of paroxysmal supraventricular tachycardia (PSVT).

Conclusion

Understanding palpitations and their potential causes like PSVT is crucial for timely and effective management.

• Accurate diagnosis through ECG and Holter monitoring is essential.

• Effective treatment includes vagal maneuvers, medications, or even catheter ablation.

• Individuals experiencing palpitations, especially recurrent or distressing ones, should seek prompt medical evaluation.

References

[1]Leonardo A Orejarena, Humberto Vidaillet, Frank DeStefano, David L Nordstrom, Robert A Vierkant, Peter N Smith, John J Hayes, Paroxysmal Supraventricular Tachycardia in the General Population, Journal of the American College of Cardiology,Volume 31, Issue 1, 1998, Pages 150-157, https://doi.org/10.1016/S0735-1097(97)00422-1

[2] Singh S, McKintosh R. Adenosine. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK519049/

[3] Hafeez Y, Quintanilla Rodriguez BS, Ahmed I, et al. Paroxysmal Supraventricular Tachycardia. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507699/