The supraventricular tachycardia ecg rhythm
The supraventricular tachycardia ecg rhythm Supraventricular tachycardia (SVT) is a common arrhythmia characterized by an abnormally rapid heart rate that originates above the ventricles, specifically within the atria or the atrioventricular (AV) node. Its hallmark feature on an electrocardiogram (ECG) is a rapid, regular rhythm that often challenges clinicians to distinguish it from other tachyarrhythmias. Understanding the ECG presentation of SVT is essential for accurate diagnosis and effective management.
Typically, the ECG in SVT reveals a narrow QRS complex, usually less than 120 milliseconds, because the electrical impulses follow the normal conduction pathway through the His-Purkinje system. The rhythm is often remarkably regular, with rates ranging from 150 to 250 beats per minute. This rapid rate can cause symptoms such as palpitations, dizziness, shortness of breath, or even syncope in affected individuals. Recognizing the subtle features of the ECG can significantly influence treatment decisions. The supraventricular tachycardia ecg rhythm
One of the most distinctive features of SVT on an ECG is the absence of visible P waves or their abnormal appearance. Since the atrial and ventricular depolarizations occur almost simultaneously or the atrial signals are hidden within the QRS complex, P waves may be either absent, inverted, or embedded within the T waves. In cases where P waves are visible, they might appear immediately before or after the QRS complex, depending on the specific type of SVT. The supraventricular tachycardia ecg rhythm
The narrow QRS complexes are indicative of supraventricular origin, setting SVT apart from ventricular tachycardias, which typically feature wide QRS complexes. The rapid, regular rhythm with a sudden onset and termination — often described as a “paroxysmal” event — is characteristic. Such episodes can be initiated by premature atrial contractions or triggered by vagal maneuvers, which temporarily slow conduction through the AV node. The supraventricular tachycardia ecg rhythm
ECG interpretation is further complicated by the various types of SVT, including atrioventricular nodal reentrant tachycardia (AVNRT), atrioventricular reciprocating tachycardia (AVRT), and atrial tachycardia. Each has subtle differences in P wave morphology and relationship to QRS complexes, but their common feature remains a rapid, narrow QRS rhythm. For instance, AVNRT often presents with P waves that are hidden within or immediately after the QRS complex, making the P wave difficult to detect. Conversely, atrial tachycardia may display P waves with abnormal morphology preceding the QRS.
Treatment of SVT depends heavily on ECG recognition. Vagal maneuvers can sometimes terminate the arrhythmia by increasing parasympathetic tone and slowing conduction. Pharmacologic agents like adenosine are often used acutely because they temporarily block AV nodal conduction, which can interrupt the reentrant circuit. In persistent or recurrent cases, catheter ablation targeting the reentry pathway offers a definitive cure. The supraventricular tachycardia ecg rhythm
In conclusion, the ECG features of supraventricular tachycardia are characterized by a narrow, rapid, and regular rhythm with absent or abnormal P waves. Recognizing these patterns facilitates prompt diagnosis and guides effective treatment, ultimately improving patient outcomes and quality of life. The supraventricular tachycardia ecg rhythm
