Adult Medical-Surgical Nursing Cardiovascular Module: Cardiac Valvular Disorders

Cardiac Valvular Disorders: Description The cardiac valves are: Aortic Pulmonary Mitral Tricuspid Disorders lead to poor blood flow through the heart, and may lead to ↓ cardiac output

Cardiac Valvular Disorders: Classification Stenosis Incompetence

Cardiac Valve Stenosis Narrowing of the valve Increases demand on the myocardium to pump blood through the valve

Cardiac Valve Incompetence Incompetence/ regurgitation: A damaged valve which leaks and does not close properly Leads to: Backflow of blood during systole and increased back pressure ↓ cardiac output

Cardiac Valvular Disorder: Aetiology Congenital Ageing: wear and tear Rheumatic heart disease or bacterial endocarditis: An auto-immune response following Rheumatic fever (less common now) or streptococcal throat infection → endocarditis and chronic bacterial vegetation around valve/ valves

Cardiac Valvular Disorder: Diagnosis History and clinical findings Chest Xray ECG Echocardiography Cardiac catheterisation: reveals degree of closure / incompetence

Prevalent Conditions Mitral stenosis Mitral incompetence Aortic stenosis Aortic incompetence

Mitral Stenosis

Mitral Stenosis: Pathophysiology Narrowing of mitral valve: This causes left atrium to force blood to left ventricle → dilatation/ hypertrophy of left atrium Atrial fibrillation: risk of thrombus/ emboli Backflow/ congestion in pulmonary circulation leads to: Increased workload of right ventricle → Right heart failure

Mitral Stenosis: Clinical Manifestations Fatigue/ dizziness (low cardiac output) Respiratory problems: Dyspnoea, cough, frequent chest infections, haemoptysis Atrial fibrillation (dysrythmia): weak often irregular pulse (risk of emboli) Diastolic murmur on auscultation

Mitral Stenosis: Medical Management Treat congestive heart failure: Diuretics, Digoxin, vasodilators (reduce afterload) Anti-dysrythmics Anticoagulants (longterm to prevent emboli) Antibiotics prior to dental or surgical procedures (to prevent endocarditis)

Mitral Stenosis: Surgery Valvotomy Valve replacement: An animal or human valve An artificial valve (prosthesis)* *With an artificial valve long-term anticoagulants required (risk of thrombus)

Mitral Incompetence

Mitral Incompetence: Pathophysiology The mitral valve does not close and leaks causing: Backflow of blood during systole from left ventricle to left atrium → cardiac output is reduced → increased pressure, dilatation and hypertrophy of left atrium Pulmonary congestion → Right heart failure

Mitral Incompetence: Clinical Manifestations Maybe symptomless Fatigue and weakness Palpitations on exertion Dyspnoea and cough Systolic murmur at apex on auscultation

Mitral Incompetence: Surgery Surgical intervention is necessary as progressively cardiac output is reduced and pulmonary congestion increased: Valvuloplasty (repair) Valve replacement Medical management of symptoms

Aortic Stenosis

Aortic Stenosis: Pathophysiology Narrowing of the aortic valve Causes increased filling and effort of the left ventricle (forcing blood through) → Left ventricular hypertrophy Left ventricular failure (maybe acute pulmonary oedema)

Aortic Stenosis: Clinical Manifestations Faintness/ dizziness (low cardiac output) Angina: O2 demand of hypertrophied left ventricle Slow forceful systole reduces diastole and filling time for coronary circulation Dyspnoea: If LVF: Copious blood-stained frothy sputum

Aortic Stenosis: Auscultation Loud systolic murmur over aortic area and vibration of turbulent blood felt by a hand over the apex

Aortic Stenosis: Management Medical: Treat angina and symptoms of LVF: Vasodilators, Digoxin, diuretics, anticoagulants Antibiotics prior to dental work or surgery to prevent endocarditis Surgery: Valvotomy Valve replacement

Aortic Incompetence

Aortic Incompetence: Pathophysiology Aortic valve is damaged and leaking Blood regurgitates from aorta during diastole into left ventricle → dilatation Left ventricle hypertrophies to force emptying into the aorta → increased systolic BP Arterial vasodilatation to compensate (↓ peripheral resistance): ↓ diastolic BP (↑ pulse pressure) → LVF

Aortic Incompetence: Clinical Manifestations Forceful heartbeat Dyspnoea on exertion and fatigue Paroxysmal nocturnal dyspnoea and orthopnoea (may lead to LVF) ↑ pulse pressure, “water-hammer” pulse (rapid strong pulse which then collapses) Diastolic murmur on auscultation

Aortic Incompetence: Management Medical management of LVF Antibiotic cover for dental or surgery to prevent endocarditis Surgery: Aortic valve replacement (This is the preferred management) Anticoagulants long-term if artificial valve

Nursing Responsibilities Physical examination ECG monitoring Weight, vital signs, fluid balance ICU nursing post-surgery Patient education on diet, degree of exercise and rest, medications Psychological/ emotional support