From the Guidelines
Supraventricular Tachycardia (SVT) can have P waves, but they are only visible in 60% of cases. The presence and appearance of P waves in SVT vary depending on the specific type of arrhythmia and the relationship between atrial and ventricular activation 1. In SVT, the P waves almost always have a different morphology from sinus P waves, which can help distinguish SVT from other types of arrhythmias 1. Some key characteristics of SVT include:
- A rapid regular tachyarrhythmia with an extremely regular R-R interval after the first 10–20 beats
- A narrow QRS complex in over 90% of infants and children
- P waves with different morphology from sinus P waves in 60% of cases
- The QRS complex is usually similar to the underlying sinus QRS, with persistent aberration being exceedingly rare 1. It is essential to consider the mechanism of the arrhythmia and the relationship between atrial and ventricular activation when evaluating the presence and morphology of P waves in SVT, as this information can guide appropriate treatment strategies, including medication selection and ablation procedures if necessary.
From the Research
Supraventricular Tachycardia (SVT) and P Waves
- The provided studies do not directly address whether SVT has P waves or not 2, 3, 4, 5, 6.
- However, it is known that SVT is characterized by an abnormal heart rhythm originating from above the ventricles, and P waves are typically associated with atrial depolarization.
- Some types of SVT, such as atrioventricular nodal reentrant tachycardia (AVNRT), may have retrograde P waves that can be difficult to detect on an electrocardiogram (ECG) 3, 4.
- Further research is needed to determine the specific characteristics of P waves in SVT, as the provided studies focus on treatment options and diagnosis rather than the electrocardiographic features of the condition.
Treatment and Diagnosis of SVT
- Vagal maneuvers, such as the Valsalva maneuver and carotid massage, are commonly used to treat SVT 2, 3, 4, 5, 6.
- Adenosine is also a frequently used treatment for SVT, particularly when vagal maneuvers are unsuccessful 3, 4.
- Electrocardiogram (ECG) is the best tool for diagnosing SVT, and it can help identify the type of SVT and guide treatment decisions 4, 5.