What is Supraventricular Tachycardia (SVT)?

Supraventricular Tachycardia (SVT) is defined as a regular and narrow complex tachycardia that occurs at a rate of 150 beats per minute (BPM) or greater. The hallmark characteristics of SVT include the absence of visible P-waves or flutter waves on the electrocardiogram (ECG), indicating that the rapid heart rate originates above the ventricles, most commonly in the atria or the AV node. This lack of discernible P-waves suggests a rapid re-entry circuit or an ectopic focus that is responsible for the tachycardia.

The other options relate to different arrhythmias or heart conditions that do not accurately reflect the characteristics of SVT. For instance, the description of a rapid heartbeat with wide QRS complexes pertains to conditions like ventricular tachycardia, while consistent P-wave patterns are indicative of sinus rhythms, not SVT. Additionally, an irregular heartbeat accompanied by chest pain might refer to conditions such as atrial fibrillation or other arrhythmias, further differentiating them from the specific criteria for identifying SVT.