What are the signs and symptoms of Supraventricular Tachycardia (SVT)?

Signs and Symptoms of Supraventricular Tachycardia

The most common presenting symptoms of SVT are palpitations (occurring in 22-86% of patients), followed by chest discomfort (5-47%), lightheadedness, dyspnea, and fatigue, with characteristic "neck pounding" or "shirt flapping" sensations particularly suggestive of AVNRT. 1, 2

Primary Symptoms

Palpitations

• Palpitations are the hallmark symptom, reported in 22% to 86% of patients depending on the study population 1, 3, 2
• Patients describe sudden onset of rapid, regular heartbeat that starts and stops abruptly 3, 4
• The sensation may be felt in the chest or neck 5

Characteristic "Neck Pounding" (AVNRT-Specific)

• Patients with AVNRT frequently describe "shirt flapping" or "neck pounding" sensations, which are highly specific for this arrhythmia type 1
• This unique symptom results from pulsatile reversed flow when the right atrium contracts against a closed tricuspid valve (cannon a-waves) 1
• This distinguishes AVNRT from AVRT, where this symptom is less common 1

Chest Discomfort or Pain

• Chest pain or discomfort occurs in 5% to 47% of patients 1, 6, 2
• Results from myocardial ischemia due to increased oxygen demand and decreased coronary perfusion time during prolonged tachycardia 7, 6
• Can also be caused by increased atrial pressures from atrial contraction against closed AV valves 6

Lightheadedness and Near-Syncope

• Lightheadedness is common, but true syncope is infrequent (occurring in approximately 4-15% of cases) 1, 7
• Syncope typically occurs just after initiation of rapid SVT or with prolonged pause after abrupt termination 7
• Elderly patients with AVNRT are more prone to syncope or near-syncope than younger patients, despite generally slower tachycardia rates 1
• Among patients experiencing SVT while driving, 50% had near-syncope symptoms and 14% experienced syncope 1

Dyspnea and Fatigue

• Dyspnea (shortness of breath) is reported in 34-38% of patients 3, 2
• Fatigue is a common complaint, particularly during prolonged episodes 3, 2
• Among patients who experienced SVT while driving, 77% felt fatigue 1

Additional Symptoms

Polyuria

• Polyuria is particularly common with AVNRT and is related to higher right atrial pressures and elevated levels of atrial natriuretic protein 1
• This symptom is more specific to AVNRT compared to AVRT or atrial flutter 1

Anxiety and Dizziness

• Anxiety is frequently reported during SVT episodes 7, 2
• Dizziness occurs in approximately 42% of patients 8

Critical Diagnostic Pitfalls

Misdiagnosis as Panic or Anxiety Disorder

• A major pitfall is misattributing SVT symptoms to panic or anxiety disorders, which occurs in 54% of patients 1
• In one study, 67% of patients with unrecognized SVT fulfilled criteria for panic disorder 1
• Women are more likely than men to be mislabeled with panic disorder 1
• This misdiagnosis leads to unnecessary treatment with anxiety medications and delays appropriate cardiac management 8, 5

Age and Gender Patterns

• Mean age of symptom onset is 32±18 years for AVNRT versus 23±14 years for AVRT in adults 1
• AVNRT patients are more likely to be female with age of onset >30 years 1
• In pediatric populations, 64% had symptoms at presentation, with an additional 20% developing symptoms during follow-up 1

Serious Complications to Recognize

Life-Threatening Presentations

• Sudden cardiac death, though rare (0.2%), can occur, particularly in patients with WPW syndrome or congenital heart disease 1, 7
• Syncope in patients with WPW syndrome should be taken seriously, though it is not necessarily associated with increased risk of sudden cardiac death 1
• Pulmonary edema can develop from rapid heart rates causing acute pulmonary congestion 7

Tachycardia-Mediated Cardiomyopathy

• Persistent SVT with fast ventricular response can lead to heart failure, especially when SVT persists for weeks to months 7, 2
• This occurs in approximately 1% of patients with untreated PSVT 2

Quality of Life Impact

• SVT significantly impacts quality of life, varying with episode frequency, duration, and whether symptoms occur at rest or only with exercise 1
• 57% of patients experienced SVT episodes while driving, with 24% considering it an obstacle to driving 1
• Women report more symptoms in every category compared to men 1