Here, you will learn about Pacemakers and Automated implantable cardioverter defibrillators
Table Of Contents
Pacemakers
Types of Pacemakers
Biventricular Pacing (Cardiac Resynchronization Therapy [CRT])
- Involves one or two leads in the ventricles and an additional lead in the coronary sinus;
- To improve synchronization of ventricular contractions
- Primarily used in heart failure patients with left ventricular dysfunction**.**
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Indication
- LVEF โค 35% and QRS duration > 120 milliseconds, with symptomatic heart failure despite optimal medical therapy.
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Permanent Pacemaker
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Indications for Permanent Pacemaker Implantation
- Irreversible Mobitz Type II Heart Block or Complete Heart Block.
- Persistent Symptomatic Bradycardia.
- Heart Rate < 40 bpm and Asymptomatic.
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Permanent pacemakers (PPMs)
Automated implantable cardioverter defibrillators (AICD)
Description
- An AICD consists of a pulse generator and leads that can sense VF and VT and deliver a shock to restore sinus rhythm.
Indications for AICDs
The primary goal of AICDs is to prevent sudden cardiac death from ventricular tachyarrhythmias.
- Primary prevention
- Cardiac Channelopathies (e.g., congenital long QT syndrome, Brugada syndrome)
- Severe congestive heart failure (EF < 35%) in NYHA Class II/III HF
- Hypertrophic obstructive cardiomyopathy
- Arrhythmogenic right ventricular cardiomyopathy
- Secondary prevention (In case the patient has a history of the following)
- Sudden cardiac arrest (e.g., due to Vfib or Unstable VT)
- Stable sustained VT
Cardiac Event Monitors
Types of Cardiac Event Monitors
- Holter Monitor
- Records continuous ECG over 1-2 days to assess for intermittent arrhythmias.
- Loop Event Monitor
- Patient-activated monitor worn for weeks to capture symptoms like palpitations.
- Implantable Loop Recorder
- Subcutaneous device implanted for long-term monitoring (months) of arrhythmias.
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๐ก Indications for Cardiac Event Monitors:
- Unexplained syncope or near-syncope.
- Recurrent unexplained palpitations.
- Monitoring for atrial fibrillation.
- Screening for ventricular arrhythmias in patients with structural heart disease.
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Comparison of PPMs, AICDs, and CRTs Indications
Device |
Common indications |
PPMs |
๐ท Symptomatic Sinus node dysfunction |
๐ท Symptomatic AV block |
|
๐ท High-risk AV block |
|
|
|
AICDs |
๐ท Primary prevention |
๐ธ Cardiac Channelopathies (e.g., congenital long QT syndrome, Brugada syndrome)
๐ธ Severe congestive heart failure (EF < 35%) in NYHA Class II/III HF
๐ธ Hypertrophic obstructive cardiomyopathy
๐ธ Arrhythmogenic right ventricular cardiomyopathy
๐ท Secondary prevention (In case the patient has a history of the following)
๐ธ Sudden cardiac arrest (e.g., due to Vfib or Unstable VT)
๐ธ Stable sustained VT
|
| CRTs | ๐ท Patients with CHF with LVEF โค 35% & a wide QRS |