Supraventricular Tachycardia (SVT) with tachycardia

From the Guidelines

Supraventricular Tachycardia (SVT) with tachycardia is a condition characterized by a rapid heart rate originating from above the ventricles, with a rate typically exceeding 100 beats per minute (bpm) at rest.

Key Characteristics of SVT

• The condition encompasses various tachyarrhythmias, including atrial and ventricular rates >100 bpm at rest, which require atrial and/or atrioventricular nodal tissues for initiation and sustenance 1.
• SVTs usually start and stop abruptly and are rarely life-threatening, but they can lead to complications such as heart failure, pulmonary edema, and myocardial ischemia if left untreated 1.
• Common symptoms of SVT include palpitations, chest discomfort, fatigue, light-headedness, shortness of breath, anxiety, dizziness, dyspnea, and syncope 1.

Diagnosis and Differentiation

• The diagnosis of SVT involves differentiating it from other types of tachycardias, such as ventricular tachycardia, using electrocardiogram (ECG) criteria, including the presence of P waves, the morphology of the QRS complex, and the relationship between atrial and ventricular activation 1.
• Table 5 from the 2015 ACC/AHA/HRS guideline provides ECG criteria to differentiate ventricular tachycardia (VT) from SVT in wide-complex tachycardia, including the assessment of QRS complexes in leads V1-V6, aVR, and the presence of AV dissociation or fusion complexes 1.

Management and Clinical Considerations

• The management of SVT depends on the underlying cause, the presence of symptoms, and the patient's clinical condition, and may involve vagal maneuvers, pharmacological therapy, or catheter ablation 1.
• Patients with SVT may experience symptoms such as palpitations, fatigue, and light-headedness, and in some cases, syncope, which can be a concern, especially in patients with underlying structural heart disease or other comorbidities 1.
• A thorough clinical history and physical examination are essential in evaluating patients with SVT, including the pattern of episodes, duration, frequency, mode of onset, and possible triggers 1.

From the Research

Definition and Symptoms of Supraventricular Tachycardia (SVT)

• Supraventricular tachycardia (SVT) is a common cardiac rhythm disturbance characterized by recurrent episodes of tachycardia, which often increase in frequency and severity with time 2.
• SVT can cause significant patient discomfort and distress, and its symptoms may include altered consciousness, chest pressure or discomfort, dyspnea, fatigue, lightheadedness, or palpitations 3.
• The uncertain and sporadic nature of episodes of tachycardia can cause considerable anxiety, leading many patients to curtail their lifestyle 2.

Diagnosis of SVT

• A diagnosis of SVT can often be made with a high degree of certainty from patient history alone, and repeated attempts at electrocardiographic documentation of the arrhythmia may be unnecessary 2.
• Electrocardiography during tachycardia, comparing it with sinus rhythm, and assessing the onset and offset of tachycardia can help deduce the underlying mechanism of SVT 4.
• Extended cardiac monitoring with a Holter monitor or event recorder may be needed to confirm the diagnosis 3.

Treatment and Management of SVT

• Treatment of SVT may not be necessary when the episodes are infrequent and self-terminating, and produce minimal symptoms 2.
• Vagal maneuvers and adenosine are first-line therapies in the acute diagnosis and management of SVT, followed by beta-blockers and calcium channel blockers if necessary 4, 3.
• Catheter ablation is a low-risk procedure with a high success rate and is recommended as the first-line method for long-term management of recurrent, symptomatic paroxysmal SVT 2, 3.
• Long-term preventive pharmacotherapy is an alternative approach in some patients, and the choice of treatment depends on several factors, including frequency of symptoms, risk stratification, and patient preference 2, 4.