It is Time to Uncover the Mysterious veil of Atrioventricular Node Pacing

Wenckebach phenomenon is a well-known electrophysiological character of the atrioventricular node (AVN). AVN-pacing during permanent pacemaker implantation is rare. We herein report the first case of Wenckebach phenomenon in a heart failure patient with chronic atrial fibrillation for more than 30 years during the His-bundle pacing (HBP) procedure. The patient’s symptoms improved significantly. AVN-pacing is available, and HBP is helpful for cardiac remodeling and clinical outcomes.

The Wenckebach Phenomenon .

: Medicine has many great pioneers, and in 1899, one such pioneer - Karel Frederik Wenckebach made a discovery which, even to this day, remains one of the fundamental concepts within electrophysiology. Since the Wenckebach Phenomenon was first described, the field of electrophysiology has developed at a rapid pace, allowing us to observe this behaviour, and its complexities, in many new ways. In a similar way, this chapter will illustrate Wenckebach behaviour across a spectrum of modalities from the 12 lead ECG, through to the intra-cardiac recordings from both electrophysiological studies and implantable cardiac devices. In doing so, we continue to shed light on the phenomenon first identified through Wenckebach’s meticulous attention to detail some 120 years ago.

Bradyarrhythmias

A bradyarrhythmia is defined as a rhythm disturbance that results in a heart rate of less than 60 bpm. It is important to note that many healthy people have a resting heart rate that is less than 60 bpm, most commonly due to sinus bradycardia (i.e. a rhythm arising from the sinus node but with a ventricular rate less than 60 bpm). Other forms of bradyarrhythmia are sinus node disease, sick sinus syndrome, first-degree atrioventricular (AV) block, second-degree AV block (which can be characterized as Möbitz type I (Wenckebach phenomenon) or Möbitz type II), and third-degree AV block (also known as complete heart block). This chapter discusses the bradyarrhythmias, focusing on their etiology, symptoms, demographics, diagnosis, prognosis, and treatment.