<prompt> Answer this question truthfullyWhat is the underlying physiology that leads to junctional bradycardia?  <response>: <reason> Normally, the atrioventricular node AVN can generate an escape rhythm of 40-60 beats per minute in case the sinoatrial node SA node or atrial pacemakers fail sinus arrest or slow sinus bradycardia or if there is complete heart block. This junctional escape rhythm generates a normal, narrow QRS complex rhythm at a rate below 60 beats per minute junctional bradycardia as the electrical impulses once they are generated are conducted with normal velocity down the usual pathways. Retrograde P waves i.e. upside down P waves due to retrograde or backward conduction may or may not be present. 