An Automatic Implantable Cardioverter-Defibrillator (AICD) is a small, implanted device that monitors and corrects abnormal heart rhythms (arrhythmias). It functions as both a defibrillator to treat life-threatening arrhythmias and, in many cases, as a pacemaker to regulate slow heartbeats.

What is an AICD?
✔ Purpose:
Designed to detect and treat dangerous heart rhythm disorders, such as ventricular tachycardia and ventricular fibrillation, which can lead to sudden cardiac arrest.
✔ How It Works:
● Continuously monitors the heart’s electrical activity for irregular rhythms.
● If a life-threatening arrhythmia is detected, it can deliver an electric shock to restore a
normal heartbeat.
● If the heart beats too slowly, some AICDs can function as a pacemaker, sending small electrical pulses to stimulate heartbeats.

Types of AICDs:
1. Traditional ICD:
Leads (wires) are implanted inside the heart to monitor and correct rhythms.
2. Subcutaneous ICD (S-ICD):
Placed under the skin with no leads inside the heart, reducing lead-related complications.

Key Benefits of AICD Therapy:
✔ Prevents sudden cardiac death by delivering life-saving shocks when needed.
✔ Continuously monitors heart rhythms, ensuring rapid response to dangerous arrhythmias.
✔ Can function as a pacemaker to regulate slow heartbeats if necessary.
✔ Improves survival rates in patients at high risk of life-threatening arrhythmias.

Overview:
A Cardiac Resynchronization Therapy (CRT) pacemaker, also known as a biventricular
pacemaker, is a specialized device used to treat heart failure by improving the synchronization
of the heart's ventricles (lower chambers). By delivering precisely timed electrical impulses, CRT enhances the heart’s pumping efficiency and alleviates heart failure symptoms.

How CRT Works:
CRT is designed for patients experiencing delayed electrical conduction in the ventricles, often
indicated by a wide QRS complex on an electrocardiogram (ECG). The device sends mild electrical signals to coordinate the contractions of both ventricles, ensuring they beat in sync, which improves cardiac output and overall heart function.

Key Features of CRT Pacemakers:
● Three Leads for Optimal Synchronization:
● One lead is placed in the right atrium.
● One in the right ventricle.
● One in the left ventricle (via the coronary sinus) to stimulate both  ventricles simultaneously.
Biventricular Pacing:
The CRT device ensures that both ventricles contract together, reducing inefficiencies in heart function.

Two Types of CRT Devices:
1. CRT-P (Pacemaker Only): Provides pacing therapy to improve ventricular coordination.
2. CRT-D (Pacemaker + Defibrillator): Includes a built-in defibrillator to treat life-threatening
arrhythmias in high-risk patients.
3. BIV LOT Pacemaker+ defibrillator with additional left bundle pacing leads

Implantation Procedure:
● The CRT device is implanted just below the collarbone through a small incision.
● Leads are carefully positioned in the heart chambers and secured
● The device is programmed to optimize ventricular synchronization.

Benefits of CRT Therapy:
✔ Improved Heart Function: Enhances pumping efficiency and cardiac output.
✔ Symptom Relief: Reduces fatigue, shortness of breath, and fluid retention.
✔ Enhanced Quality of Life: Increases the ability to perform daily activities and exercise.
✔ Fewer Hospitalizations: Lowers the risk of heart failure-related complications and admissions.

Who Should Consider CRT?
CRT is recommended for patients with:
Moderate to severe heart failure symptoms despite optimal medical treatment.
A wide QRS complex (suggesting delayed electrical conduction).
Reduced left ventricular function (weakened heart pumping ability).