Infective endocarditis

This is an ultrasound (I think) of an infective endocarditis (I think). The lumpy bit is a vegetation (I think).

Definition

Infection of the heart valves.

Epidemiology

About 1 in 25,000 incidence rate.

Pathophysiology

Since the valves do not have their own blood supply, the immune system can't get white cells to the valves, making them susceptable to bacterial infection.

There are two main types:

• Acute - usually caused by Staphylococcus epidermidis, comes on over a few days/weeks.
• Subacute - usually caused by Streptococcus viridans, and comes on over weeks.

Risk Factors

• Prosthetic heart valve.
• Recent dental work.
• Injecting drugs - can lead to staph infection from skin.
• Previous rheumatic fever - can cause damage to valves, making it easier for bacteria to stick on.

There are others, specially anything causing heart shape problems, weird murmurs or valve damage.

Clinical Features

The two things that should ring alarm bells are below. If you get them, move onto treatment:

1. Fever, combined with
2. New onset murmur.

Other things that can happen include

• Tiredness - this occurs in about 90% of patients!
• New rashes, joint pain, and other signs of systemic infection.

Management

Generally benzylpenicillin/vancomycin + gentamicin. This depends on the microbiology.

Prognosis

Mortality rate of about 50%. NOT GOOD!