Bradycardia and Pacemakers/CRT

  • Gaurav A. Upadhyay
  • Jagmeet P. Singh


Bradyarrhythmias are a heterogeneous group of cardiac rhythm disturbances which are implicated in over 40 % of sudden cardiac deaths in the hospital. Broadly classified, they are manifestations of either a failure of cardiac impulse generation or impulse propagation. They may be physiologic and benign, as in sinus bradycardia and sinus arrhythmia in athletes, or pathologic and warranting intervention, as in compromising bradycardia from sinus node dysfunction or ventricular asystole from high-grade atrioventricular (AV) block after an anterior myocardial infarction (MI).

The purpose of this chapter is to review the pathophysiology of various bradyarrhythmias and to review treatment options available. In addition, a brief overview of pacemakers and cardiac resynchronization therapy (CRT) will be provided.


Cardiac Resynchronization Therapy Respiratory Sinus Arrhythmia Transcatheter Aortic Valve Replacement Sinus Bradycardia Complete Heart Block 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



American College of Cardiology


Atrial fibrillation


American Heart Association




British Pacing Electrophysiology Group


Beats per minute


Complete heart block


Cycle length


Cardiac resynchronization therapy


Corrected sinoatrial node recovery time






Food and Drug Administration


Hypertrophic cardiomyopathy


Heart failure


Heart rate


Heart Rhythm Society


Implantable cardioverter defibrillator


Left anterior fascicular block


Left bundle branch block


Left posterior fascicular block


Long QT syndrome type 1


Left ventricular


Left ventricular Ejection fraction


Myocardial infarction


North American Society for Pacing and Electro­physiology


New York Heart Association


Permanent pacemakers


Right atrium


Right bundle branch block


Right ventricle




Sinoatrial conduction time


Sinus node dysfunction


Sinoatrial node recovery time


Ventricular tachycardia


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Copyright information

© Springer-Verlag London 2014

Authors and Affiliations

  • Gaurav A. Upadhyay
    • 1
  • Jagmeet P. Singh
    • 2
  1. 1.Harvard Medical School Cardiology Division, Department of MedicineMassachusetts General HospitalBostonUSA
  2. 2.Harvard Medical School Cardiac Arrhythmia Service, Cardiology Division, Department of MedicineMassachusetts General HospitalBostonUSA

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