Endocarditis

Also called Infective endocarditis, Heart valve infection

Infection on a heart valve, presenting as weeks of feeling vaguely unwell. Blood cultures before antibiotics is the step that gets missed.

What it is

Infection of the inner lining of the heart, usually on a valve. Bacteria enter the bloodstream and settle on a valve that is damaged, artificial, or occasionally normal.

It is uncommon and it kills around one in five people who get it, largely because it is diagnosed late. The reason is that it presents as weeks of feeling unwell: fever, tiredness, sweats, weight loss, aching. People are treated for a series of viruses and post-viral fatigue while a valve is being destroyed.

**The pattern to recognise is unexplained fever lasting more than a week in somebody with a heart valve problem, a replacement valve, congenital heart disease, or who injects drugs.** In that combination, endocarditis must be excluded.

The critical practical point is that **blood cultures must be taken before antibiotics are started.** Antibiotics given for a presumed chest or urine infection sterilise the cultures and can make the diagnosis impossible to prove for weeks, while treatment goes on being inadequate.

Complications include valve destruction and heart failure, and fragments breaking off to cause stroke, kidney damage or abscesses elsewhere.

Treatment is weeks of intravenous antibiotics, often six, and surgery in around half of cases.

Dental and oral health is the main preventable route in.

Signs you might notice

Fever, sweats and chills, often low grade and persistent over weeks.

Fatigue, aching, loss of appetite, weight loss.

Breathlessness, or a new or changed heart murmur.

Small painless red or brown spots on the palms and soles, painful nodules on the fingers, splinter-like marks under the nails, and spots on the whites of the eyes. These classic signs are uncommon but distinctive.

Stroke-like symptoms, or sudden pain in a limb or the abdomen from an embolus.

Blood in the urine.

Urgent: unexplained fever for more than a week in anybody with valve disease, a replacement valve, a pacemaker, congenital heart disease, or who injects drugs.

**Ask for blood cultures before any antibiotic is given.**

How it can affect day-to-day life

The prevention that matters most is dental. Everybody with valve disease or a replacement valve should be registered with a dentist, go regularly, and tell them. Routine antibiotic prophylaxis before dental work is no longer given to most people in the UK, and good oral health has replaced it as the strategy, which needs explaining because people remember the old advice.

People who inject drugs are at high risk and are also the group most likely to be treated dismissively, to self-discharge, and to die of it. Six weeks of intravenous antibiotics is extremely difficult without stable housing, and services that plan for that get better outcomes.

Long courses of intravenous antibiotics are often delivered at home through an outpatient service, with a long line that carries its own infection risk.

Fatigue after treatment lasts months.

Anybody who has had endocarditis is at high risk of getting it again, and needs to know the symptoms for life.

Supporting someone well

For unexplained fever over a week with any heart valve risk factor, ask directly about endocarditis.

Insist on blood cultures before antibiotics. This is the single most important step.

Register with a dentist, attend regularly, and tell them about the valve.

Keep the mouth healthy; this is now the main prophylaxis.

Carry a card or note stating the valve condition or replacement.

Report any fever, however mild, promptly rather than waiting.

For people who inject drugs, plan the practical side of a six-week course early, including housing and pain management, or the treatment will not be completed.

Ask about line care and what to report while on home intravenous antibiotics.

Where to get help

A GP practice urgently for persistent unexplained fever with a valve risk factor; A and E if unwell.

Cardiology, infection and cardiac surgery teams; a dentist for prevention.

999 for stroke symptoms or sudden severe breathlessness.

British Heart Foundation on 0808 802 1234.