An ICD is a complex but quietly powerful device. Day to day it does not bother you. But knowing what it does, what to do if it fires, and how to live well with it makes a real difference — particularly in the first months.

This guide is meant to live in a drawer near where you keep your medication. The contact card on the last page is the most important section; tear it out and put it on the fridge if it helps.

Some patients feel anxious about an ICD in the early weeks. That is common and normal. We talk about it openly. Resources for emotional adjustment are in the back of this guide.

An ICD has three jobs:

• Watch your heart's rhythm continuously. Every beat is sensed and compared to programmed thresholds.
• Pace your heart if it's too slow — exactly like a regular pacemaker.
• Deliver a defibrillation shock if it detects a dangerous fast rhythm (ventricular tachycardia or ventricular fibrillation) that could otherwise cause sudden cardiac arrest.

Before the device delivers a shock, it usually tries a less intense option first — antitachycardia pacing (ATP), a brief burst of fast pacing that often stops the dangerous rhythm without you feeling anything. If ATP doesn't work, the device proceeds to a shock.

The shock takes a fraction of a second. It delivers about 25–40 joules of energy through the lead and the heart muscle. Patients describe it as a strong, brief kick in the chest. The shock is not pleasant — but it is doing exactly what it was designed to do.

What kind of ICD do you have?

Three main types are in use:

• Transvenous ICD — most common. Generator near the collarbone; one lead through a vein into the heart.
• Subcutaneous ICD (S-ICD) — generator on the left side of the chest; lead tunneled under the skin near the sternum. No lead in the heart.
• Extravascular ICD (EV-ICD) — newest. Generator on the left side; lead behind the sternum (but outside the heart and veins).

The implant locations and recovery details differ slightly. Your discharge paperwork tells you which one you have.

This is the section most patients want to know first. Here is what to do.

If you feel well after the shock

• Sit down somewhere safe.
• Take a moment to assess — are you having chest pain? Severe shortness of breath? Did you nearly faint?
• Call our office the same day, even after hours. The remote monitor will already have transmitted the event to us, but we want to hear from you to know how you felt.
• One shock with full recovery is not a 911 situation. We will see you the next business day for an in-person check.

If you feel unwell, or you receive a second shock within 24 hours

• Call 911. Two shocks close together — especially with symptoms — is a sign that the underlying rhythm is unstable and you need urgent evaluation in an emergency room.

What about people touching you during a shock?

The shock energy is confined to your chest. Someone touching you during the shock may feel a brief tingle but is not in danger. This is worth knowing if family worries about touching you in the months after.

Phantom shocks

Some patients feel what seems like a shock when nothing has actually happened — a sudden jolt, a startled-awake sensation in the middle of the night. The device's remote monitor records every shock; if there's no event, it was not a shock. These "phantom" sensations are real to the patient but harmless. Tell us about them at your next visit.

Incision care

• Keep the incision dry for 5 days. Shower from the neck down or use a washcloth.
• No baths, hot tubs, or swimming for 2 weeks.
• Some bruising and a small lump are normal. The lump is the device.

Arm restrictions

• Do not raise the device-side arm above your shoulder for 2 weeks.
• No lifting more than 5–10 pounds with that arm for 4–6 weeks.
• S-ICD and EV-ICD patients have slightly different restrictions — your discharge paperwork is specific.

Driving

This is different for ICDs than for pacemakers. The restrictions depend on why your ICD was placed:

• Primary prevention (no prior cardiac arrest, ICD placed because of risk): no driving for 1 week.
• Secondary prevention (had a cardiac arrest or sustained VT): no driving for 6 months.
• After any shock for a sustained VT or VFib event: no driving for 6 months from that event.
• Commercial driving (truck, bus): typically permanent restrictions per Department of Transportation rules.

State laws vary. Texas does not have a fixed driving law for ICD patients but our office writes specific restrictions that we ask you to follow.

Activity

• Walking starts day one.
• Light cardio after week 2.
• Full exercise routine resumes at 6–8 weeks unless we tell you otherwise.
• Contact sports (football, hockey, martial arts) are generally not recommended even after recovery.

MRI

Most modern ICDs are MRI-conditional. The MRI center must follow a specific protocol — your device card has the manufacturer's instructions. Tell the MRI staff you have an ICD and bring your device card.

Airport security

Walk through normally. Carry your device card. Modern detectors do not affect the ICD. The alarm may go off; allow a few extra minutes.

Magnets

A magnet held over an ICD temporarily suspends its shock function (used in the hospital sometimes during surgery). Casual magnet exposure — refrigerator magnets, magnetic clasps on jewelry, magnetic phone cases — is not strong enough to do this. Strong industrial magnets, large speakers, MRI machines, arc welding — keep your distance.

Phones and electronics

Cell phones, computers, microwaves, hair dryers, kitchen appliances — all fine. Don't carry your phone in a chest pocket directly over the device. Bluetooth headphones contain small magnets; keep them 6 inches from the device site.

Dental and surgical procedures

Tell every dentist and surgeon you have an ICD. Electrocautery and some dental tools can interfere; the team will plan accordingly. The device may need to be temporarily put into a non-shocking mode for some surgeries.

Sex

Resume when comfortable, typically by 2 weeks. The ICD does not interfere with sexual function. Some patients are anxious about getting a shock during sex — this is a normal worry and very rarely a real issue, particularly once the device is well-programmed.

An ICD changes how patients think about their bodies. Anxiety, sleep disturbance, and avoidance behaviors are common — particularly in the first 6 months and after any shock.

What we see

• Anxiety about a shock — particularly during exercise, intimacy, or activities you used to enjoy. This usually fades over months as the device proves itself trustworthy.
• Sleep issues — sometimes the awareness of the device disrupts sleep for the first few weeks.
• Avoidance — some patients stop exercising, traveling, or socializing because they fear a shock. This is the most important pattern to break.
• Family anxiety — partners and children often worry more than the patient.

What helps

• A clear understanding of what the device does — and what its alarms mean. Read this handbook with your family.
• Cardiac rehabilitation — a structured 12-week program that lets you ease back into activity with rhythm monitoring and a physical therapist who knows your situation.
• Counseling or therapy — many patients benefit from a few sessions with a therapist familiar with cardiac patients. Ask us for a referral.
• Connection with other ICD recipients — support groups exist in person and online. Many patients say this helps more than anything else.

If you find yourself avoiding things you used to enjoy, having trouble sleeping for more than a few weeks, or feeling persistent dread about the device, please tell us. This is part of our care, not a separate issue.

• 1–2 weeks: Wound check in clinic.
• 3 months: Full device interrogation; we adjust settings now that the leads have stabilized.
• Every 3–6 months thereafter: Remote monitoring through your home transmitter; in-office visit annually.
• Battery: ICD batteries last 5–8 years on average, depending on use. We start planning the generator change 6 months before depletion.

Your home transmitter checks your device daily and immediately reports any concerning event to us — including any shock. You do not need to do anything for this to work. Keep it powered on and connected.

This handbook is educational. It does not create a doctor-patient relationship and does not replace your visits. Your situation may differ — talk to Dr. Colombowala before making decisions about your care.

© 2026 Ilyas K. Colombowala, MD. All rights reserved.