Cardiology · Electrophysiology & Devices
CRT & CRT-D Devices
Resynchronising the failing heart — with a built-in guardian
Medically reviewed by Dr Kunal Ajay Patankar, DrNB (Cardiology)
What it is
In some heart failure patients, the heart's walls contract out of sync, wasting each beat's effort. Cardiac Resynchronisation Therapy (CRT) uses an additional lead to re-time the contraction so the heart pumps as one — often improving symptoms, heart function and survival.
A CRT-D combines resynchronisation with a defibrillator that automatically corrects life-threatening fast rhythms, protecting against sudden cardiac death.
Who needs it
- Heart failure with reduced ejection fraction despite optimal medications
- A wide QRS (electrical delay) on ECG — typically left bundle branch block
- Persistent breathlessness limiting daily life
- Survivors of, or those at high risk for, dangerous ventricular arrhythmias (CRT-D)
How it happens, step by step
1
Candidacy review
ECG, echo and medication history confirm you meet criteria where CRT genuinely helps — patient selection is everything.
2
Implantation
Like a pacemaker, but with a third lead threaded into a vein on the heart's left side — the technically decisive step.
3
Defibrillator testing
For CRT-D, sensing and therapy settings are configured to recognise and treat dangerous rhythms instantly.
4
Optimisation
Device timing is fine-tuned with echo guidance so every beat is synchronised.
Recovery, honestly
- Typically 1–2 days in hospital
- Arm precautions for 2–3 weeks, like a pacemaker
- Many patients feel less breathless within weeks as the heart remodels
- Regular device clinics and continued heart failure medications are essential
Common questions
Will the shock hurt?
Most patients never receive a shock. If one occurs, it is momentary — described as a sudden thump — and it exists to save your life. Frequent shocks prompt reprogramming or rhythm treatment.
Is CRT a cure for heart failure?
It is a powerful treatment, not a cure. Combined with modern heart failure medication, it can substantially improve how you feel and how long you live.
CRT-P or CRT-D — which do I need?
It depends on your arrhythmia risk, age and overall condition. We decide together after a transparent discussion of benefit and cost.
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