The paroxysmal supraventricular tachycardia ecg characteristics
The paroxysmal supraventricular tachycardia ecg characteristics Paroxysmal supraventricular tachycardia (PSVT) is a common arrhythmia characterized by sudden episodes of rapid heart rate originating above the ventricles. Its diagnosis heavily relies on the interpretation of the electrocardiogram (ECG), which provides vital clues to identify and differentiate PSVT from other arrhythmias. Understanding the ECG characteristics of PSVT is essential for clinicians to ensure prompt and accurate treatment.
The hallmark of PSVT on an ECG is a rapid, narrow QRS complex tachycardia, typically with a heart rate ranging from 150 to 250 beats per minute. The narrow QRS complexes indicate that the electrical impulse is traveling through the normal His-Purkinje system, distinguishing PSVT from ventricular tachycardia, which usually presents with wide QRS complexes. The onset of PSVT episodes is often abrupt, with the tachycardia starting and ending suddenly, which can sometimes be captured clearly on the ECG. The paroxysmal supraventricular tachycardia ecg characteristics
One of the defining features of PSVT is the presence of P waves that are either hidden within the QRS complex or appear just before or after it, making the atrial activity less conspicuous. In many cases, P waves are inverted in the inferior leads (II, III, aVF), suggesting atrial activation from an ectopic focus or reentrant circuit located near the AV node. The PR interval, when measurable, is typically short, often less than 120 milliseconds, further supporting the diagnosis of a supraventricular origin. The paroxysmal supraventricular tachycardia ecg characteristics
The paroxysmal supraventricular tachycardia ecg characteristics The reentrant mechanism is the most common cause of PSVT, involving an abnormal conduction pathway or circuit. During an episode, the ECG often exhibits a regular, rapid rhythm with narrow QRS complexes. The episodes may be precipitated by premature atrial or ventricular contractions, stress, caffeine, or other stimulants. The termination of PSVT is usually sudden, often with vagal maneuvers such as carotid sinus massage or the administration of adenosine, which temporarily blocks AV nodal conduction and restores normal rhythm.
In some cases, especially during ongoing episodes, the ECG may show a “warm-up” or “cool-down” phenomenon, where the rate gradually accelerates or decelerates. This is characteristic of reentrant tachycardias involving the AV node or accessory pathways. Differentiating PSVT from other narrow complex tachycardias like atrial flutter or atrial fibrillation involves assessing the regularity and the atrial activity pattern. For example, atrial flutter typically shows a sawtooth pattern of flutter waves, whereas atrial fibrillation exhibits irregularly irregular rhythm without discernible P waves. The paroxysmal supraventricular tachycardia ecg characteristics
In summary, the ECG characteristics of paroxysmal supraventricular tachycardia include a narrow QRS complex tachycardia with a rapid, regular rhythm, often with indistinct or hidden P waves, and a short PR interval. Recognizing these features allows for timely and appropriate management, which may include vagal maneuvers, pharmacological therapy, or electrophysiological interventions.
Understanding the ECG signature of PSVT enables healthcare providers to differentiate it from other arrhythmias, facilitating effective treatment decisions and improving patient outcomes. The paroxysmal supraventricular tachycardia ecg characteristics
