What are the potential complications of supraventricular tachycardia (SVT)?

Complications of Supraventricular Tachycardia

Untreated supraventricular tachycardia (SVT) can result in serious complications including heart failure, pulmonary edema, and myocardial ischemia secondary to increased heart rate, with adults with congenital heart disease facing additional risks of stroke and sudden cardiac death. 1

Common Complications of SVT

• Heart Failure: Persistent SVT with fast ventricular response can lead to tachycardia-mediated cardiomyopathy, especially when SVT persists for weeks to months 1

• Pulmonary Edema: Rapid heart rates during SVT episodes can cause acute pulmonary congestion and edema due to increased atrial pressures 1

• Myocardial Ischemia: Prolonged tachycardia increases myocardial oxygen demand while decreasing coronary perfusion time, potentially resulting in ischemia 1

• Syncope: Occurs in approximately 15% of SVT patients, usually just after initiation of rapid SVT or with a prolonged pause after abrupt termination of the tachycardia 1

• Stroke Risk: Particularly elevated in adults with congenital heart disease who develop SVT 1

• Sudden Cardiac Death: Rare but serious complication, especially in patients with congenital heart disease or pre-excitation syndromes like Wolff-Parkinson-White syndrome 1

Population-Specific Complications

Adults with Congenital Heart Disease (ACHD)

• SVT in ACHD patients is associated with significantly increased risk of:

  • Heart failure
  • Stroke
  • Sudden cardiac death 1

• SVT occurs in 10-20% of ACHD patients and represents a more serious condition in this population 1

• Particularly high risk in patients with:

  • Ebstein anomaly (20-45% develop AT)
  • Single-ventricle/Fontan procedures
  • Tetralogy of Fallot
  • Transposition of the great arteries
  • Atrial septal defects 1

Medication-Related Complications

• Adenosine (commonly used for acute SVT treatment):
  • Cardiac arrest, sustained ventricular tachycardia, and myocardial infarction (fatal and non-fatal) 2
  • Sinoatrial and atrioventricular nodal block (first, second, or third-degree) 2
  • Bronchoconstriction and respiratory compromise 2
  • Hypotension due to peripheral vasodilation 2
  • Cerebrovascular accidents (hemorrhagic and ischemic) 2
  • Seizures (new-onset or recurrence) 2

Symptom-Related Complications

• Quality of Life Impact: Common symptoms during SVT episodes include:

  • Palpitations
  • Chest discomfort
  • Fatigue
  • Light-headedness
  • Shortness of breath
  • Anxiety
  • Dizziness
  • Dyspnea 1, 3

• These symptoms can significantly impact daily activities and quality of life, even when not life-threatening 3, 4

Special Considerations

• Pre-excitation Syndromes: Patients with accessory pathways (particularly Wolff-Parkinson-White syndrome) who develop atrial fibrillation are at risk for extremely rapid ventricular rates that can degenerate into ventricular fibrillation 1, 5

• Pediatric Patients: Neonates and infants with SVT generally present with signs of acute congestive heart failure rather than the palpitations typical in older children and adults 6

• Chronic-Permanent Tachycardia: Can result in a secondary form of dilated cardiomyopathy that may be reversible with rate control 6

Prevention of Complications

• Early recognition and appropriate treatment of SVT is essential to prevent long-term complications 3, 4

• Catheter ablation has a success rate of approximately 95% with a recurrence rate of less than 5%, making it an excellent option for preventing recurrent SVT and its associated complications 5

• Patients with pre-excitation on ECG and history of palpitations should be promptly referred for electrophysiological evaluation due to risk of significant morbidity and possibly sudden death 1