SVT Case Study – #3

A 45-year-old female presents to the EP lab with complaints of palpitations and the following 12 lead ECG that was recorded in the emergency room 2 weeks prior. 12 Lead ECG:  What do you observe?   Answer: Retrograde P Waves  Notice the retrograde P waves,...

The What, Where & Why of Double Potentials

What are double potentials?   Answer:  The term double potential literally means two potentials or signals. Most referred to in the atrium, double potentials are atrial electrograms with two discrete deflections per beat separated by an isoelectric or low...

EP 101 – Catheter Placement

Question: Today, let’s go back to the basics and discuss catheter placement and waveforms. In the following electrogram, none of the intracardiac channels are labeled. Identify each catheter location, the associated waveforms, and the rhythm.   Answer: This is an...

Troubleshooting – 1

This week’s electrogram:  This patient was brought into the EP lab for ablation of typical atrial flutter. She has had no previous ablations and was in normal sinus rhythm when placed on the monitor. The following electrogram was recorded at soon as the...

EP 101 – More Signals & Catheters

Where are the following catheter located?  What signals are displayed on each channel?  What is the rhythm?  Answer: The first three channels displayed are surface ECG leads. A full 12-lead ECG was placed on the patient, but only a few were displayed. Also of note,...

EP 101 – Signals & Catheter Positioning

What is the catheter location in the following electrogram?  Answer Near the Bundle of His The catheter is labeled coronary sinus (CS); however, the signals do not reflect that location. Notice the A, H, and V signals recorded. Instead of placement in the coronary...