From the Guidelines
A supraventricular rhythm on an EKG is a potentially life-threatening condition, particularly if misdiagnosed, and requires careful evaluation to distinguish it from ventricular tachycardia (VT) and to identify the underlying arrhythmia mechanism. According to the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1, a 12-lead ECG obtained during tachycardia and during sinus rhythm may reveal the etiology of tachycardia. The ECG can be used to classify the tachycardia as regular or irregular, and to identify the presence of P waves, which can help to distinguish between different types of supraventricular rhythms.
Some key features to look for on an ECG to diagnose a supraventricular rhythm include:
- Narrow QRS complexes (less than 120 milliseconds)
- P waves before each QRS complex (though these may be absent or abnormal in certain arrhythmias like atrial fibrillation)
- A regular or irregular rhythm depending on the specific type
- Heart rates that can range from slow to very fast
- The presence of atrioventricular (AV) dissociation or fusion complexes, which can indicate VT 1
The clinical significance of a supraventricular rhythm varies widely, from benign conditions like sinus arrhythmia to potentially serious conditions requiring immediate intervention, such as atrial fibrillation with a rapid ventricular response or supraventricular tachycardia (SVT) with hemodynamic instability. Proper identification and classification of the specific supraventricular rhythm is essential for appropriate treatment, which may include observation, medication (such as beta-blockers, calcium channel blockers, or antiarrhythmics), cardioversion, or ablation procedures 1.
In terms of management, the guideline recommends that patients with supraventricular tachycardia be evaluated and treated based on their underlying arrhythmia mechanism, with a focus on restoring a normal sinus rhythm and preventing recurrence 1. This may involve the use of medications such as adenosine, beta-blockers, or calcium channel blockers, as well as procedures such as cardioversion or ablation. The goal of treatment is to improve symptoms, prevent complications, and improve quality of life, and the choice of treatment will depend on the specific type of supraventricular rhythm, the patient's underlying medical conditions, and their individual preferences and values 1.
From the Research
Significance of Supraventricular Rhythm on an EKG
The significance of a supraventricular rhythm on an electrocardiogram (EKG) can be understood by considering the following points:
- Supraventricular tachycardia (SVT) is an abnormal rapid cardiac rhythm that involves atrial or atrioventricular node tissue from the His bundle or above 2.
- SVT can cause significant patient discomfort and distress, and is a common cause of hospital admissions 3.
- The most common SVTs include atrioventricular nodal re-entrant tachycardia, atrioventricular re-entrant tachycardia, and atrial tachycardia 2, 4, 3.
- Symptoms of SVT may include palpitations, chest discomfort, dyspnea, fatigue, lightheadedness, or altered consciousness 2, 4, 5.
Diagnosis and Management
Diagnosis and management of SVT can be approached as follows:
- Diagnostic evaluation may include a comprehensive history and physical examination, electrocardiography, and laboratory workup 2.
- Extended cardiac monitoring with a Holter monitor or event recorder may be needed to confirm the diagnosis 2, 4, 6.
- Acute management of paroxysmal SVT is similar across the various types and is best completed in the emergency department or hospital setting 2.
- Vagal maneuvers, adenosine, beta blockers, and calcium channel blockers may be used in the acute management of SVT 2, 4, 3, 5.
- Catheter ablation is a highly effective treatment for preventing recurrence of PSVT, with success rates of 94.3% to 98.5% 5.
Importance of Referral to a Cardiologist
Referral to a cardiologist is important for the following reasons:
- Clinicians should have a low threshold for referral to a cardiologist for electrophysiologic study and appropriate intervention such as ablation 2.
- All patients treated for SVT should be referred for a heart rhythm specialist opinion 3.
- Long-term treatment is dependent on several factors, including frequency of symptoms, risk stratification, and patient preference, and should be managed in consultation with a cardiologist 3, 5.