The Clinical Spectrum of Bradyarrhythmias "To Pace or Not to Pace"

Asystolic bradyarrhythmias, documented on ambulatory electrocardiographic monitoring, present a perplexing problem regarding clinical management. These asystolic episodes can be instigated by intrinsic and extrinsic influences. Intrinsic events are precipitated by disease in the conduction system, while extrinsic incidents are modulated by vagal tone. Vagal-mediated bradyarrhythmias represent a diverse group of arrhythmias that are poorly understood. There is a deficiency in the literature for defining vagal-mediated bradycardia and hence without a full appreciation of the multitude of characteristics that define atrioventricular block, it can be challenging to make a firm diagnosis. This review discusses the elemental characteristics of bradyarrhythmias in combination with the current guidelines to enable risk stratification for permanent cardiac pacing. Cardiac pacing has been established to alleviate symptoms and improve longevity in patients with conduction system disease, whereas vagal-mediated bradycardias are a benign phenomenon and thus it is imperative that such rhythms are correctly identified.