cardiac_valve_disease.pdf

9/29/23 Valvular heart disease 2023 1 Learning objectives • Define the terms stenosis and incompetence • Describe the common causes of cardiac valve stenosis and incompetence • Define the term infective endocarditis • Name some risk factors for infective endocarditis • Describe the composition of...

9/29/23 Valvular heart disease 2023 1 Learning objectives • Define the terms stenosis and incompetence • Describe the common causes of cardiac valve stenosis and incompetence • Define the term infective endocarditis • Name some risk factors for infective endocarditis • Describe the composition of a vegetation • Name some probable causative organisms • Describe the local and systemic complications of infective endocarditis • Describe the principles of diagnosis, treatment and prevention of infective endocarditis 2 1 9/29/23 The problem • 10% of heart failure involves valve disease • Four valves – all can be affected • Primary and secondary problems 3 4 2 9/29/23 5 Definition of stenosis and incompetence • Stenosis Narrowing of the valve outlet caused by thickening of valve cusps, or increased rigidity or scarring. • Incompetence Or insufficiency or regurgitation (which is what happens) caused by incomplete seal when valves close, allowing blood to flow backwards remember vegetations 6 3 9/29/23 Valves and heart sounds • First: mitral and tricuspid - systole • Second: aorta and pulmonary – diastole Signs • Aortic stenosis • Aortic incompetence • Mitral stenosis • Mitral incompetence 7 Common causes of cardiac valve stenosis and incompetence • Congenital heart disease: bicuspid valve, atresia • Cardiomyopathy (hypertrophic, dilated) • Acquired – Rheumatic fever – Myocardial infarction – Age related – idiopathic aortic calcific stenosis – Endocarditis 8 4 9/29/23 Aortic stenosis General and systematic pathology / edited by James C.E. Underwood, Simon S. Cross. Edinburgh : Churchill Livingstone Risks Left ventricular hypertrophy Syncope Sudden cardiac death 9 10 5 9/29/23 dyspnoea 11 Post MI 12 6 9/29/23 13 Causes of mitral incompetence • Cusp damage – for example – Rheumatic heart disease – scarring, contraction – Floppy valve & Marfan syndrome - stretch – Infective endocarditis - perforation • Chordae – as above • Papillary muscle – eg post MI • Valve ring – as above, age 14 7 9/29/23 Mitral incompetence General and systematic pathology / edited by James C.E. Underwood, Simon S. Cross. Edinburgh : Churchill Livingstone, 2009. Most often post-rheumatic fever Risks Pulmonary hypertension Right ventricular hypertrophy 15 General and systematic pathology / edited by James C.E. Underwood, Simon S. Cross. Edinburgh : Churchill Livingstone 16 8 9/29/23 17 Define infective endocarditis • Infection of valve with formation of thrombotic vegetations • Virulence of organisms determines damage and severity of the clinical illness • Classified as acute and sub-acute • Bacteraemia is common 18 9 9/29/23 Risk factors for infective endocarditis • Valve damage – As before, especially after rheumatic fever • Bacteraemia – Dental – Catheterisation – 10% unknown – iv drug abuse • Immunosuppression General and systematic pathology / edited by James C.E. Underwood, Simon S. Cross. Edinburgh : Churchill Livingstone 19 Rheumatic fever • Acute multisystem disease – heart (myocarditis, valvulitis, pericarditis), joints, connective tissue • 3 weeks post Streptococcal infection (usually pharyngitis) • Immune mediated rather than direct infection • Occurs in children: 4-16 years • May occur in recurrent episodes • Chronic valve disease decades later 20 10 9/29/23 Composition of a vegetation Group D Streptococcus, gut commensals, skin Strep (Coxiella, fungi, Candida) General and systematic pathology / edited by James C.E. Underwood, Simon S. Cross. Edinburgh : Churchill Livingstone. 21 Local and systemic complications of infective endocarditis Immune Infective Thrombotic General and systematic pathology / edited by James C.E. Underwood, Simon S. Cross. Edinburgh : Churchill Livingstone. 22 11 9/29/23 • Acute Native Valve Endocarditis – valves may be normal – aggressive disease – virulent organisms, such as Staph. aureus and group B streptococci • Subacute Native Valve Endocarditis – abnormal valves – indolent but may deteriorate – alpha-haemolytic streptococci, enterococci 23 • Prosthetic valve endocarditis – 10-20% of cases – 5% of mechanical and bio-prosthetic valves become infected – mitral are more susceptible than aortic – early onset: Staph. aureus, gram-negative bacilli, Candida species – late onset: staphylococci, alpha-haemolytic streptococci, enterococci 24 12 9/29/23 • IV Drug abuse – 75% have no underlying valvular abnormalities – 50% involve the tricuspid valve – Staph. aureus most common For more reading see http://emedicine.medscape.com/article/216650-overview#a2 25 Principles of diagnosis, treatment and prevention of infective endocarditis • Treat Strep. infection with antibiotics • Prophylactic cover for invasive procedures eg dental work • Replace damaged valves • • • • Clinical suspicion & signs Imaging – especially echocardiography Blood culture Intravenous antibiotics 26 13 9/29/23 Learning objectives • Define the terms stenosis and incompetence • Describe the common causes of cardiac valve stenosis and incompetence • Define the term infective endocarditis • Name some risk factors for infective endocarditis • Describe the composition of a vegetation • Name some probable causative organisms • Describe the local and systemic complications of infective endocarditis • Describe the principles of diagnosis, treatment and prevention of infective endocarditis 27 14