Ecg of supraventricular tachycardia
Ecg of supraventricular tachycardia The electrocardiogram (ECG) of supraventricular tachycardia (SVT) presents distinctive features that help clinicians identify this common arrhythmia. SVT refers to a rapid heart rhythm originating above the ventricles, typically involving the atria or the atrioventricular (AV) node. Recognizing its ECG characteristics is crucial for prompt diagnosis and management, especially since patients often present with sudden onset of rapid palpitations, dizziness, or even chest discomfort.
Ecg of supraventricular tachycardia On an ECG, SVT usually manifests as a narrow QRS complex tachycardia, with a rate generally ranging from 150 to 250 beats per minute. The hallmark feature is the rapid, regular rhythm with a heart rate that exceeds the normal sinus rhythm. Because the rhythm is so fast, P waves can be elusive or even hidden within the preceding T waves, making it challenging to distinguish the atrial activity. When visible, P waves may appear merged with the QRS complex or inverted in the inferior leads if the origin is from an ectopic atrial focus.
One of the key diagnostic clues in the ECG is the regularity of the rhythm. SVT typically produces a highly regular rhythm due to the consistent reentrant circuit or automatic focus responsible for the arrhythmia. The narrow QRS complexes are due to normal ventricular conduction pathways, indicating that the impulse travels through the His-Purkinje system normally. Ecg of supraventricular tachycardia
Ecg of supraventricular tachycardia The morphology of the QRS complexes in SVT remains narrow unless there is aberrant conduction or pre-existing bundle branch block. This narrow complex tachycardia can sometimes be confused with sinus tachycardia or atrial flutter; however, specific features help differentiate them. For example, atrial flutter often exhibits sawtooth flutter waves, usually best seen in the inferior leads, which are absent in SVT. Sinus tachycardia, in contrast, maintains the appearance of normal P waves before each QRS, at a slower rate.
In some cases, the ECG during SVT may reveal subtle changes such as a shortened PR interval if the arrhythmia involves an accessory pathway, as seen in Wolff-Parkinson-White (WPW) syndrome. The presence of a delta wave, a slurred upstroke of the QRS complex, can point toward this diagnosis. During episodes of SVT, these features can assist in identifying the underlying mechanism and guiding treatment options.
Ecg of supraventricular tachycardia Treatment management often depends on the ECG characteristics. Vagal maneuvers, like the Valsalva maneuver, can sometimes terminate the SVT by increasing parasympathetic tone. If pharmacologic intervention is needed, drugs such as adenosine are effective, and their action can be monitored through changes in the ECG, often causing transient AV block and resetting the heart rhythm. In persistent cases, catheter ablation may be considered, especially when a specific reentrant pathway is identified.
In conclusion, the ECG of supraventricular tachycardia is characterized by a rapid, regular, narrow QRS complex rhythm with often concealed P waves. Recognizing these features is essential for timely diagnosis and appropriate management, reducing potential complications associated with sustained tachyarrhythmias. Ecg of supraventricular tachycardia
