Pauses and Their Connection to the P-P Intervals Part 2
Overdrive Suppression
We have here in Figure 1 what is most likely an AV nodal reentrant tachycardia (AVNRT). Could it possibly be an AV reentrant tachycardia with orthodromic conduction through an accessory pathway? Possibly. Could it be an atrial tachycardia with the P wave hidden in the preceding T wave? Possibly. Then why am I saying that it is an AVNRT? Because when there is a rapid, regular, narrow-complex tachycardia with no signs of upright or inverted P waves, statistically the most likely cause – by far – is AV nodal reentrant tachycardia (AVNRT).
But the tachycardia suddenly and abruptly ends. Why? And where did it end?
The last recorded depolarization is a ventricular depolarization (QRS). That tells me that the impulse made it down the slow pathway and excited the ventricles before turning back up and blocking in the fast pathway. Had it blocked in the slow pathway we might have seen the inscription of a retrograde P wave – but we didn’t.
Pauses and Their Connection to the P-P Intervals 2_compressedPdf: Pauses and Their Connection to the P-P Intervals
Dr. Jerry W. Jones: Medicus of Houston was established by Jerry W. Jones, MD FACEP FAAEM. Graduate of Tulane University and the University of Texas Health Science Center at San Antonio. Dr. Jones has been on the teaching faculties of the University of Oklahoma and The University of Texas Medical Branch in Galveston. He is a published author who has also been featured in the New York Times and the Annals of Emergency Medicine for his work in the developing field of telemedicine. In addition, Dr. Jones is also a Fellow of the American College of Emergency Physicians, a Fellow of the American Academy of Emergency Medicine and a member of the European Society of Emergency Medicine