Cardiac Resynchronisation Therapy (CRT): How a Small Device Can Make a Big Difference in Heart Failure

What Is Cardiac Resynchronisation Therapy (CRT)?

If you or a loved one has been living with heart failure, your cardiologist may have mentioned a cardiac resynchronisation therapy (CRT) device. The name sounds technical, but the idea behind it is straightforward — and it has helped millions of people around the world live more comfortably and actively.

The heart is essentially a pump. It has four chambers that need to squeeze in a coordinated rhythm to push blood efficiently around the body. In many people with heart failure, the two lower chambers — the left and right ventricles — fall out of step with each other. One contracts a split-second too late. This mis-timing, called dyssynchrony, means the heart works harder but pumps less blood. Over time, it leads to worsening breathlessness, fatigue, and swelling in the legs.

A CRT device — sometimes called a biventricular pacemaker — sends tiny, carefully timed electrical signals to both ventricles at once, helping them contract together, the way they should. Think of it like a conductor bringing an orchestra back into harmony.

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How Does a CRT Device Work?

A CRT device is roughly the size of a large wristwatch face. It is implanted just under the skin near the collarbone, usually under local anaesthesia with sedation, so the patient is comfortable throughout. The procedure typically takes one to two hours.

Three thin, flexible wires called leads are threaded through blood vessels into the heart:

• One lead goes to the right atrium (top-right chamber)
• One lead goes to the right ventricle (bottom-right chamber)
• One lead goes to the left ventricle (bottom-left chamber, via the coronary sinus)

The device continuously monitors the heart's natural rhythm and delivers small electrical pulses to keep both ventricles contracting in sync. Most patients do not feel these pulses at all.

CRT-P vs CRT-D: What Is the Difference?

You may hear two abbreviations used:

• CRT-P (CRT Pacemaker): Provides resynchronisation only.
• CRT-D (CRT Defibrillator): Does everything CRT-P does, plus it can detect dangerously fast heart rhythms (ventricular tachycardia or fibrillation) and deliver a shock to restore a normal rhythm. This combined device is recommended for patients who are also at higher risk of sudden cardiac arrest.

Your cardiologist will recommend which type is right for you based on your individual heart function, risk profile, and overall health.

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Who Benefits From CRT?

Not every person with heart failure will need a CRT device. Careful assessment is required. Based on current evidence and international guidelines (including those from the European Society of Cardiology and the American Heart Association), CRT is typically considered when a patient:

1. Has heart failure with reduced ejection fraction (HFrEF): The ejection fraction (EF) is a measure of how much blood the heart pumps out with each beat. A normal EF is 55–70%. CRT is generally considered when EF is ≤35%.

2. Is already on optimal medical therapy: Medications such as beta-blockers, ACE inhibitors/ARBs, and aldosterone antagonists should have been tried first at the right doses. CRT works alongside medicines, not instead of them.

3. Has a wide QRS complex on the ECG: The QRS complex is a wave on the ECG (electrocardiogram) that represents ventricular contraction. A wider QRS — typically ≥130–150 milliseconds, especially with a pattern called left bundle branch block (LBBB) — is the strongest indicator that the ventricles are out of sync and likely to respond well to CRT.

4. Remains symptomatic: Patients in NYHA (New York Heart Association) functional Class II, III, or ambulatory Class IV — meaning they still feel breathless or limited despite medicines — are the ones most likely to benefit.

A 55-year-old who, for illustrative purposes, has an EF of 28%, a wide LBBB on ECG, and is breathless walking to the kitchen despite maximum medications would be a classic candidate for CRT assessment.

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What Are the Expected Benefits?

Clinical trials and real-world experience with CRT have shown meaningful improvements for suitable patients:

• Improved symptoms: Many patients report feeling less breathless and more energetic within weeks to months of CRT implantation.
• Improved heart function: In a significant proportion of patients, the ejection fraction rises, sometimes substantially. The heart can actually reverse-remodel — meaning it becomes less enlarged and stronger.
• Reduced hospitalisations: Fewer emergency admissions for worsening heart failure.
• Better quality of life: Patients are often able to walk further, climb stairs, and enjoy daily activities they had previously given up.
• Improved survival: In patients with the right criteria, particularly those with LBBB, CRT has been shown in large trials to reduce mortality compared with medical therapy alone.

It is important to set realistic expectations. Not everyone responds equally. Roughly 60–70% of well-selected patients show a meaningful positive response, which is why careful patient selection — the kind done with thorough echocardiographic and ECG assessment — matters so much.

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What Happens After the Procedure?

Most patients are discharged within one to two days. There is a small recovery period of around four to six weeks during which you will be advised to:

• Avoid heavy lifting or raising the arm on the implant side above shoulder height
• Keep the wound dry and clean while it heals
• Attend a follow-up visit to check wound healing and device settings

After this, the device is checked regularly — either in the clinic or, in some cases, via remote monitoring, where the device transmits data wirelessly to your care team between visits. This means any change in your heart rhythm or device function can be reviewed promptly without you needing to travel each time.

The device battery typically lasts 8 to 12 years, after which a straightforward generator replacement procedure is performed. The leads usually remain in place.

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Living With a CRT Device in Rajkot

Day-to-day life with a CRT device is generally very manageable. In Rajkot and across Gujarat, patients often ask about practical concerns:

• Travelling: You will be given a device ID card to carry. Airport security wands and standard metal detectors are safe, but inform security staff about your device.
• Mobile phones: Modern smartphones are safe to use. Avoid placing them directly over the device pocket for prolonged periods.
• MRI scans: Many newer CRT devices are MRI-conditional. Let any treating doctor or radiologist know about your device before an MRI.
• Exercise: Light to moderate activity, as advised by your cardiologist, is encouraged. Your device will support you during activity by adjusting its pacing rate.
• Diet and medications: Continue your prescribed medicines and heart-healthy diet. The device complements your treatment — it does not replace lifestyle care.

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Key Takeaways

• CRT (cardiac resynchronisation therapy) is a device-based treatment that helps the two main pumping chambers of the heart contract in a coordinated, synchronised way.
• It is recommended for patients with heart failure, reduced ejection fraction (≤35%), a wide QRS on ECG (especially LBBB), and ongoing symptoms despite optimal medicines.
• CRT can improve symptoms, exercise capacity, heart function, and survival in well-selected patients.
• There are two main types — CRT-P (pacemaker only) and CRT-D (with a built-in defibrillator).
• Recovery is relatively straightforward, and the device requires regular follow-up checks.
• Not everyone with heart failure needs CRT — proper assessment by a qualified cardiologist is essential.
• Living with a CRT device is compatible with a full, active daily life for most patients.

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If you or a family member has been diagnosed with heart failure and would like to understand whether a cardiac resynchronisation therapy (CRT) device could be a suitable option, please do not hesitate to book a consultation with a qualified interventional cardiologist for a personalised evaluation.