Home /

Pacemaker (PCM), ICD, CRT

Pacemaker (PCM), Implantable cardioverter-defibrillator (ICD), Cardiac resynchronization therapy (CRT), Biventricular pacing

Single-Chamber Pacemaker

• Has one electrode inserted into:
• The right atrium or right ventricle
• The electrode can perform both pacing and sensing of the chamber
  
  
• Inserted into the right atrium, for example:
• In cases of sick sinus syndrome with intact AV conduction
• Inserted into the right ventricle, for example:
• In cases of bradyfibrillation of the atrium

Dual-Chamber Pacemaker

• Has 2 electrodes inserted into:
• Right atrium and right ventricle
• Each electrode can perform pacing and sensing of the chamber
  
  
• AV block III degree
• The atria and ventricles are electrically isolated from each other
• The dual-chamber pacemaker eliminates:
• Asynchronous activity of the atria and ventricles (AV dissociation)
• The risk of asystole during ventricular rhythm
• The atrial electrode performs atrial sensing
• The ventricular electrode performs ventricular pacing

CRT (Cardiac Resynchronization Therapy)

• CRT is a device for cardiac resynchronization therapy
• It is used for dyssynchronous ventricular contraction
• For example, in left bundle branch block
• CRT is often referred to as a biventricular pacemaker
• It ensures synchronous pacing of the ventricles
• CRT has 3 leads:
• Right atrium
• The atrial lead performs sensing
• Right ventricle
• Left ventricle (inserted through the coronary sinus)
• The ventricular leads perform synchronous pacing
• Sometimes, CRT has only 2 leads in the ventricles
  
  
• There are 2 types of CRT devices:
• CRT-P (Cardiac Resynchronization Therapy - Pacemaker)
• (Biventricular pacemaker)
• CRT-D (Cardiac Resynchronization Therapy - Defibrillator)
• (Biventricular pacemaker + Defibrillator)
• Protects the heart from malignant ventricular arrhythmia (like an ICD)

Implantable Devices

• Pacemaker is a device that protects the heart from bradycardia
• ICD = Pacemaker + Defibrillator. ICD protects the heart from bradycardia and from malignant ventricular arrhythmia
• CRT-P is a biventricular pacemaker that synchronizes ventricular contraction
• CRT-D = CRT-P + Defibrillator. It is a biventricular pacemaker with protection against malignant ventricular arrhythmia