Module 1
Topic 1
Lesson 3

Sinus rhythm from inside the heart

Petr Peichl
Head of EP labs

What will you learn?

  • how signal sequence looks like in normal sinus rhythm
  • recognise all electrograms during normal sinus rhythm
  • basic knowledge about the catheters so you can build on
  • how to train your eye to spot immediately when something is off

About this scenario

  • Sinus rhythm leads to typical activation sequence in intracardiac electrograms. It is essential to know this pattern in order to quickly detect all alterations potentially caused by arrhythmias or present arrhythmias substrate.
  • On the atrial level, the earliest activity is recorded in the high-right atrium, then along the His catheter and sequentially in the coronary sinus catheter (from proximal to distal electrodes: CS 9/10 --> 1/2, i.e. concentric activation as opposed to eccentric).
  • Physiologic AV conduction is characterized by AH 50-150ms and HV 35-55ms (more on that in Lesson 6).
  • Ventricular activation is preceded by the His signal, which is followed by local ventricular activation. More over it is also reflected in CS catheter (as fare field) and locally (near field) on RVA catheter. More on far and near field in next Lesson.
  • Alteration from this sequence might indicate arrhythmia or presence of arrhythmia substrate e.g. accessory pathway.