Video coming soon — Dr. Luni explains icd in plain language
What does an ICD do?
An ICD works like a sophisticated pacemaker combined with an internal defibrillator. It constantly monitors your heart rhythm. If it detects ventricular tachycardia (VT) or ventricular fibrillation (VF) — life-threatening arrhythmias that can cause sudden cardiac arrest — it delivers a precisely timed electrical shock to reset the heart back to normal rhythm.
Modern ICDs also have pacing capabilities and can be programmed to deliver anti-tachycardia pacing (ATP) — a painless sequence of rapid pacing pulses that can terminate many VT episodes without a shock.
Who needs an ICD?
- Survivors of sudden cardiac arrest or ventricular fibrillation
- Patients with low heart function (ejection fraction below 35%) due to prior heart attack or cardiomyopathy
- Patients with hypertrophic cardiomyopathy (HCM) at high risk
- Patients with genetic arrhythmia syndromes (Long QT, Brugada, ARVC, CPVT)
- Patients with sustained ventricular tachycardia
Types of ICDs
Transvenous ICD (TV-ICD)
The traditional ICD, with leads placed inside the heart through a vein. Provides both defibrillation and pacing capabilities. Implanted in a pocket under the collarbone.
Subcutaneous ICD (S-ICD)
A newer option where the device and lead sit entirely under the skin — no leads inside the heart or blood vessels. Ideal for younger patients or those without a need for pacing. Dr. Luni implants S-ICDs as part of his practice.
What does an ICD shock feel like?
Patients often describe an ICD shock as a sudden, forceful thump in the chest — similar to being kicked. It is momentarily uncomfortable but passes quickly. Anti-tachycardia pacing (ATP), which can stop many VT episodes, is painless.
An ICD does not prevent arrhythmias — it treats them automatically when they occur. For patients at risk of sudden cardiac death, it is the single most effective life-saving intervention available.