pacemaker

Examples of pacemaker in the following topics:

• Artificial Pacemakers

  • A pacemaker, or artificial pacemaker, so as not to be confused with the heart's natural pacemaker is an implantable medical device that uses electrical impulses, delivered by electrodes contacting the heart muscles, to regulate the beating of the heart.
  • Single-chamber pacemaker.
  • Dual-chamber pacemaker.
  • Rate-responsive pacemaker.
  • This artificial pacemaker, manufactured by St.

• Electrical Events

  • The SA and AV nodes act as a pacemaker for the heart, determining the rate at which it beats, even without signals from the larger nervous system of the human body.
  • Without autonomic nervous stimulation, the SA node will set the heart rate itself, acting as the primary pacemaker for the heart.

• Arrhythmia

  • These palpitations have also been known to be caused by atrial/ventricular fibrillation, wire faults, and other technical or mechanical issues in cardiac pacemakers/defibrillators.
  • The sinoatrial node is a single specialized location in the atrium which has a higher automaticity (a faster pacemaker) than the rest of the heart and, therefore, is usually responsible for setting the heart rate and initiating each heart beat.
  • Arrhythmias with atrial origin include: Premature Atrial Contractions (PACs), Wandering Atrial Pacemaker, Atrial flutter , and Atrial fibrillation (Afib).

• Agonists, Antagonists, and Drugs

  • Increases in vagal activity to the SA node decreases the firing rate of the pacemaker cells by decreasing the slope of the pacemaker potential and decreasing heart rate.

• Heart Failure

  • Sometimes it is treated with implanted devices (pacemakers or ventricular assist devices) and occasionally a heart transplant.

• Mechanism and Contraction Events of Cardiac Muscle Fibers

  • An action potential, induced by the pacemaker cells in the sinoatrial (SA) and atrioventricular (AV) nodes, is conducted to contractile cardiomyocytes through gap junctions.

• Aging and the Cardiovascular System

  • These palpitations have also been known to be caused by atrial/ventricular fibrillation, wire faults, and other technical or mechanical issues in cardiac pacemakers/defibrillators.

• Checking Circulation

  • During each heartbeat, a healthy heart has an orderly progression of depolarization that starts with pacemaker cells in the sinoatrial (SA) node, spreads out through the atrium, passes through the atrioventricular node down into the bundle of His and into the Purkinje fibers, and down and to the left throughout the ventricles.