Cardiac Resynchronization Therapy (CRT)

Introduction

Cardiac Resynchronization Therapy (CRT), also known as biventricular pacing, is a treatment designed for patients with heart failure who have problems with the electrical conduction of the heart. This therapy helps synchronize the beating of the heart’s ventricles, improving the efficiency of heart function and relieving symptoms of heart failure.

Who Needs CRT?

Patients with heart failure who may benefit from CRT typically have: - Reduced Ejection Fraction (<35%) – indicating weakened pumping function of the heart - Wide QRS complex (≥130 ms) on ECG – suggesting electrical dyssynchrony - Symptoms of Moderate-to-Severe Heart Failure (NYHA Class II-IV) - Left Bundle Branch Block (LBBB) or other conduction delays affecting heart synchronization

How CRT Works

CRT involves implanting a special pacemaker with three leads: 1. One lead in the right atrium (optional, depending on patient needs) 2. One lead in the right ventricle 3. One lead in the left ventricle (via the coronary sinus to stimulate the left ventricular wall)

The device then coordinates electrical impulses to make sure both ventricles contract together, rather than inefficiently.

Benefits of CRT

• Improves heart function and efficiency
• Reduces heart failure symptoms (fatigue, breathlessness, fluid retention)
• Decreases hospitalization rates
• Enhances quality of life and exercise capacity
• Can be combined with an implantable cardioverter defibrillator (CRT-D) in patients at high risk of sudden cardiac death

Possible Risks and Complications

Like any procedure, CRT implantation has risks, including: - Infection at the implantation site - Lead dislodgement or malfunction - Device-related complications (battery depletion, inappropriate pacing) - Rare allergic reactions to materials used during implantation

Conclusion

CRT is a well-established therapy for appropriately selected patients with heart failure and electrical dyssynchrony. It significantly improves quality of life, reduces hospitalization, and enhances heart function. If you have heart failure symptoms, consult a cardiologist to determine whether CRT is a suitable treatment option for you.

Source recommendations

1. European Society of Cardiology (ESC) Guidelines on Cardiac Pacing and Cardiac Resynchronization Therapy

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Cardiac-Pacing-and-Cardiac-Resynchronization-Therapy
2. https://academic.oup.com/eurheartj/article/42/35/3427/6358547
3. https://pubmed.ncbi.nlm.nih.gov/34455430/
4. https://academic.oup.com/eurheartj/article/34/29/2281/401445
5. https://pubmed.ncbi.nlm.nih.gov/23801827/

2. American Heart Association (AHA)/American College of Cardiology (ACC)/Heart Rhythm Society (HRS) Guidelines for the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
2. https://pubmed.ncbi.nlm.nih.gov/29097320/
3. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193
4. https://pubmed.ncbi.nlm.nih.gov/29084733/
5. https://www.hrsonline.org/guidance/clinical-resources/2017-ahaacchrs-guideline-management-patients-ventricular-arrhythmias-and-prevention-sudden-cardiac