Heart block

Also called Atrioventricular block, Bradycardia, Pacemaker

The heart's electrical signal failing to get through. Often harmless, sometimes the reason an older person keeps collapsing.

What it is

A delay or failure in the electrical signal travelling from the top chambers of the heart to the bottom ones.

It is graded. First-degree block is a delay only and usually needs nothing. Second-degree block sometimes needs treatment. Complete, or third-degree, heart block means no signal gets through at all, and the heart runs on a slow, unreliable backup rhythm. That causes fainting, breathlessness and sudden death, and it is treated with a pacemaker.

The commonest cause is age-related fibrosis of the conducting system. Others are heart attack, heart surgery, Lyme disease, sarcoidosis, and medicines: beta blockers, some calcium channel blockers, digoxin and rate-controlling drugs for atrial fibrillation.

The practical point in this library is the older person having unexplained falls or blackouts. Complete heart block is a treatable, dramatic cause, an ECG takes minutes, and it is frequently not done because the falls are attributed to frailty. A pacemaker in that situation is transformative.

Pacemakers are common, reliable and generally straightforward. They are checked periodically, they last around 10 years, and modern ones are MRI-conditional, though every scan needs checking against the device.

Signs you might notice

Often none, particularly with first-degree block.

Fainting or near-fainting, sometimes with no warning at all.

Falls without explanation, especially in an older person who cannot recall a trip.

Breathlessness, tiredness, reduced exercise tolerance.

A slow pulse, often below 50 beats per minute.

Chest discomfort, light-headedness, confusion.

999: collapse, chest pain, severe breathlessness, or a very slow pulse with symptoms.

Urgent: any blackout, especially without warning, and any new very slow pulse.

Anybody with unexplained falls or blackouts should have an ECG. It is quick, cheap, and it is the test that finds this.

How it can affect day-to-day life

The unexplained fall in an older person is the recurring theme in this library, and heart block belongs on the list alongside postural hypotension, medicines and subdural haematoma.

Where blackouts are intermittent, a standard ECG may be normal and a longer recording, a 24-hour monitor or an implanted loop recorder, is what catches it. Asking for that is reasonable if events keep happening.

Living with a pacemaker is undramatic. Household appliances, microwaves and airport security are fine; the specific cautions are strong magnets, some industrial equipment, and carrying a mobile phone in a pocket directly over the device.

Driving rules apply after a blackout and after implantation, and are usually short. Ask rather than assume.

Medicines that slow the heart should be reviewed rather than continued automatically, and reversing a drug cause is sometimes better than a device.

Supporting someone well

Ask for an ECG for any unexplained fall or blackout in an older person.

Ask for prolonged monitoring if events recur and the ECG was normal.

Review medicines that slow the heart: beta blockers, diltiazem, verapamil, digoxin.

Learn the driving rules after a blackout or after a pacemaker.

Carry the pacemaker identification card and show it before any scan, surgery or dental diathermy.

Keep pacemaker checks; they are how a battery running down is caught.

Report hiccups that are persistent and rhythmic, swelling or redness over the device, or a return of symptoms.

Do not accept unexplained falls as ageing without a heart tracing.

Where to get help

A GP practice for an ECG and referral to cardiology.

999 for collapse, chest pain or severe breathlessness.

The pacemaker clinic for anything about the device.

British Heart Foundation on 0808 802 1234, and Arrhythmia Alliance for rhythm problems and devices.