Atropine on junctional escape rhythm11/25/2023 ![]() beta-blockers, calcium-channels blockers).Įach of the specialised structures involved in cardiac conduction has an intrinsic rate of autorhythmicity.Īutorhythmicity refers to the rate of spontaneous depolarisation, and therefore, the number of times the heart beats per minute. Iatrogenic causes of bradycardia are also very common with the widespread use of rate-controlling medications (e.g. hypocalcaemia, hyperkalaemia) or carotid sinus stimulation. ![]() This is usually seen in athletes who have a low resting heart rate.īradycardia may develop due to numerous external factors including hypothermia, increased intracerebral pressure, autonomic dysfunction, metabolic disturbances (e.g. vagal tone) may lead to a reduction in heart rate through its control on the SAN. ![]() Most commonly, an increase in parasympathetic activity (i.e. These intrinsic abnormalities in conduction leading to bradycardia are commonly due to degenerative fibrosis, ischaemia, hypertensive heart disease or infiltration (e.g. Depending on the level and severity of the block, it may appear as a bradyarrhythmia. This can occur within the SAN, AVN or bundle branches. When there is failure to transmit normal electrical activity this leads to a ‘block’ in the electrical pathway. For example, if the sinoatrial note (SAN) fails to undergo spontaneous depolarisation the atrioventricular node (AVN) may initiate electrical activity. Within the heart, a slow rate may occur due to failure to initiate, or transmit, electrical activity.įailure to initiate electrical activity can cause another part of the heart to take over as the primary pacemaker. We refer to all the abnormally slow heart rhythms as bradyarrhythmias.īradyarrhythmias may develop due to a variety of intrinsic or extrinsic factors. Bradycardia refers to an abnormally slow heart rate.īradycardia is usually defined an abnormally slow heart rate less than 60 bpm.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |