Cardiac Resynchronization Therapy CRT

Overview of cardiac resynchronization therapy 

Cardiac resynchronization therapy is a specialized form of pacemaker therapy for heart failure patients whose heart chambers are not beating in a coordinated way. It helps the heart pump more effectively by synchronizing contractions of the ventricles. 

Candidates for CRT 

CRT is generally considered for patients who: 

• Have symptomatic heart failure (typically NYHA class II–IV). 
• Have a left ventricular ejection fraction (LVEF) of 35% or less. 
• Show a prolonged QRS duration (often ≥130–150 ms) with left bundle branch block pattern. 
• Are already receiving guideline-directed medical therapy without sufficient symptom relief. 

Preparation for CRT 

• Patients may undergo imaging (such as echocardiogram or cardiac MRI) to assess heart function. 
• An ECG is used to evaluate electrical conduction. 
• Blood tests and medication review are part of the pre-procedure workup. 
• Instructions will be given to stop certain medications or fast before the procedure. 

Recovery from CRT 

• Most patients are monitored overnight and discharged the next day. 
• Minor discomfort at the implant site is common for a few days. 
• Physical activity may be limited for several weeks to allow the leads to settle. 
• Follow-up visits are scheduled to check device function and heart rhythm. 
• Improvement in symptoms may take weeks or months as the heart adapts. 

Risks for CRT 

While CRT is generally safe, possible risks include: 

• Infection or hematoma at the device site. 
• Lead displacement requiring repositioning. 
• Rare complications like pneumothorax, cardiac perforation, or arrhythmia. 
• Non-response to CRT—some patients may not experience symptom improvement.