Complications of Supraventricular Tachycardia

Common Complications of SVT

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
Heart Failure: Persistent SVT with fast ventricular response can lead to tachycardia-mediated cardiomyopathy, especially when SVT persists for weeks to months 1, 2
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 2, 3
Stroke Risk: Particularly elevated in adults with congenital heart disease who develop SVT 1, 4
Sudden Cardiac Death: Rare but serious complication, especially in patients with congenital heart disease or pre-excitation syndromes like Wolff-Parkinson-White syndrome 1, 4

SVT in adults with congenital heart disease is associated with significantly increased risk of heart failure, stroke, and sudden cardiac death 1, 3, 4, 5
SVT occurs in 10-20% of adults with congenital heart disease patients and represents a more serious condition in this population 4
Particularly high risk in patients with Ebstein anomaly, Tetralogy of Fallot, Transposition of the great arteries, and atrial septal defects 3, 4

Common symptoms during SVT episodes include palpitations, chest discomfort, fatigue, light-headedness, shortness of breath, anxiety, and dizziness 1, 3, 5

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 2
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 2, 5

The drop in blood pressure during SVT is greatest in the first 10-30 seconds, with shorter ventriculoatrial intervals associated with greater mean BP decrease, according to the American Heart Association, as reported in Circulation 6
Typical AVNRT causes marked initial fall in systemic BP with only partial recovery, resulting in stable hypotension and reduced cardiac output, as noted by the American Heart Association in Circulation 6

Syncope occurs in approximately 15% of SVT patients and should prompt serious evaluation, particularly in elderly patients or those with congenital heart disease, as stated by the American College of Cardiology in Circulation 6
Patients experiencing SVT while driving face safety risks, with 14% experiencing syncope while driving, according to the European Society of Cardiology, as reported in Circulation 6
Evaluate for underlying structural heart disease, as heart failure, hypertension, and valvular disease predispose to persistent SVT and complications, as recommended by the European Society of Cardiology in the European Heart Journal 7, 8