VALVULAR DISORDERS

• Valvular heart disease is any disease process involving one or more of the valves of the heart.
• Valve problems may be –
  • Congenital – inborn
  • Acquired - due to another cause later in life

Heart valve

• The valves of the heart allows blood flow in only one direction through the heart into the pulmonary artery and aorta by opening and closing in response to the blood pressure changes.
• The four valves in the heart are classify in two group -
  • Atrioventricular (AV) valves - between the atria and ventricles, are –
    • Tricuspid Valve – right side
    • Mitral Valve (Bicuspid Valve) – left side
  • semilunar (SL) valves - between arteries leaving the heart and ventricles, are-
    • Pulmonary Valve
    • Aortic Valve

Problems In Valve

• When any of the heart valves do not close or open properly, blood flow is affected. Its three types -
  • Regurgitation - When valves do not close completely, blood flows backward through the valve, a condition called regurgitation.
  • Stenosis - When valves do not open completely, a condition called stenosis, the flow of blood through the valve is reduced.
  • Prolapse - Stretching of the valve leaflet into the atrium during systole

Physiology ■■■ Pathophysiology

Acquired Valvular Disorder

• Disorders of Mitral valve are –
  • Mitral Valve Prolapse
  • Mitral Regurgitation,
  • Mitral Stenosis
• Disorders of the Aortic Valve are –
  • Aortic Regurgitation
  • Aortic Stenosis
• Tricuspid and pulmonic valve disorders also occur, usually with fewer symptoms and complications.
• Regurgitation and stenosis may occur at the same time in the same or different valves.

Mitral valve prolapse

Definition

• Also known as Barlow syndrome; Myxomatous mitral Systolic click-murmur syndrome
• Mitral valve prolapse is a Myxomatous disorder in which, the mitral valve leaflet prolapsed into the left atrium during the contraction phase of the heart. In sever condition valve does not close properly it allows blood to backflow.

Pathophysiology

• In patients with mitral valve prolapse, the mitral apparatus (valve leaflets and chordae) becomes affected by a process called myxomatous degeneration.
• In myxomatous degeneration, the structural protein collagen forms abnormally and causes thickening, enlargement, and redundancy of the leaflets and chordae.
• When the ventricles contract, the redundant leaflets prolapse (flop backwards) into the left atrium, sometimes allowing leakage of blood through the valve opening (mitral regurgitation).
• When severe, mitral regurgitation can lead to heart failure and abnormal heart rhythms.

Etiology

• For most people, the cause for mitral valve prolapse is unknown.
• Some people may inherit the condition, especially those associated with connective tissue disorders like marfan's syndrome.
• Other causes may the dilatation of annulus and the elongation of chordae tendineae and papillary muscles
• It is seen most commonly in women from 20 to 40 years old, but also occurs in men.

Clinical manifestation

• Many patients with mitral valve prolapse do not have symptoms.
• The group of symptoms found in patients with mitral valve prolapse is called "mitral valve prolapse syndrome" and includes: -
  • Chest pain - Sharp, dull, or pressing, lasting from a few seconds to several hours, usually not related to myocardial ischemia
  • Fatigue and weakness, even after little exertion
  • Dizziness
  • Light-headedness when rising from a chair or a bed
  • Shortness of breath with activity or when lying flat (orthopnea)
  • Sensation of feeling the heart beat (palpitations)
  • Depression (in 70% of cases)
• When mitral regurgitation occurs, symptoms may be related to this leaking.

Assessment and Diagnostic Findings

• Physical exam - thrill (vibration) over the heart, and heart murmur ("midsystolic click") present. The murmur gets longer and louder when you stand up.
• Blood pressure is usually normal.
• Echocardiogram is the most common test used to diagnose mitral valve prolapse.
• Other tests may also be used to diagnose mitral valve prolapse or a leaky mitral valve:
  • Cardiac catheterization
  • Chest x-ray
  • CT scan of the chest
  • ECG (may show arrhythmias such as atrial fibrillation)
  • MRI of the heart

Management

• Mitral valve prolapse usually requires no specific treatment.
• The condition usually requires no activity restrictions, but the person should avoid competitive sports if he has a definite click and murmur of significant mitral insufficiency.
• There are no special restrictions on diet.
• Caffeine, alcohol, and stimulant intake should be limited if heart irregularities are present.
• Maintain normal fluid intake. Dehydration can provoke MVP.
• If a woman is pregnant, she should tell her obstetrician or midwife that she has mitral valve prolapse.
• Most women with mitral valve prolapse require no specific precautions.
• A woman may require antibiotics if she needs a urinary catheter or has an infection at the time of delivery and has a heart murmur of mitral insufficiency.
• Surgery - On rare occasions, worsening valve leakage or extreme prolapse may require surgery to repair the valve

Mitral Regurgitation

Definition

• Also known as Mitral valve insufficiency or mitral incompetence
• Mitral regurgitation is a disorder of the heart in which the mitral valve does not close properly during the contraction phase of the heart, it allows blood to backflow.
• Prevalence - 2% of the population, equally in males and females.

Etiology - causes and risk factor

• There are two forms of mitral valve regurgitation: acute and chronic .

Acute

• Endocarditis, mainly S. aureus
• Papillary muscle rupture or dysfunction,
• including mitral valve prolapse

Chronic

• Rheumatic fever
• Marfan's syndrome
• Cardiomyopathy

Clinical manifestation

Acute Mitral Regurgitation

• Congestive heart failure like signs and symptoms - shortness of breath, pulmonary edema, orthopnea, and paroxysmal nocturnal dyspnea,
• Symptoms suggestive of a low cardiac output state - decreased exercise tolerance and palpitations are also common
• Cardiovascular collapse with shock (cardiogenic shock) may be seen in individuals with acute mitral regurgitation due to papillary muscle rupture or rupture of a chorda tendinea.

Chronic Mitral Regurgitation

• May be asymptomatic, with a normal exercise tolerance and no evidence of heart failure.
• These individuals may be sensitive to small shifts in their intravascular volume status, and are prone to develop volume overload (congestive heart failure).

Assessment and Diagnostic Findings

Physical exam –

• S1 - usually soft and with a laterally displaced apex beat and followed by a high-pitched holosystolic murmur ( the whole of systole) at the apex, radiating to the back or clavicular area.

• S3 present
• In acute cases,
  • the murmur and tachycardia may be only distinctive signs.
  • Patients with mitral valve prolapse often have a mid-to-late systolic click and a late systolic murmur.

Diagnostic test -

• Chest X-ray showing dilated left ventricle
• Echocardiography to detect mitral reverse flow, dilated left atrium and ventricle and decreased left ventricular function
• ECG
• Cardiac catheterization
• CT scan of the chest
• MRI of the heart

Management

• In acute mitral regurgitation secondary to a mechanical defect in the heart, the treatment of choice is urgent mitral valve replacement.
  • If the patient is hypotensive prior to the surgical procedure, an intra-aortic balloon pump may be placed in order to improve perfusion of the organs and to decrease the degree of mitral regurgitation
  • If the individual is normotensive, vasodilators (NGT) may be of use to decrease the afterload seen by the left ventricle and thereby decrease the regurgitant fraction.
• In chronic mitral regurgitation
  • Treatment to relieve symptoms or to prevent or treat complications
  • Afterload reduction with vasodilators
  • Any hypertension is treated aggressively, by diuretics and low sodium diet
  • digoxin
  • Antiarrhythmics
• Surgery
  • Mitral Valve Repair
  • Mitral Valve Replacement

Mitral Stenosis

Definition

• Also known as Mitral valve obstruction
• Mitral Stenosis is a disorder of the heart valve in which the mitral valve does not open fully, restricting blood flow.

Etiology - causes and risk factor

• Almost always caused by rheumatic heart disease
• other cause in adults are (rarely) –
  • Infective endocarditis
  • Calcium deposits forming around the mitral valve
  • Radiation treatment to the chest
  • Some medications
• It is the most common valvular heart disease in pregnancy

Clinical manifestation

• Heart failure symptoms, such as dyspnea on exertion, orthopnea and paroxysmal nocturnal dyspnea
• Palpitations
• Chest pain
• Hemoptysis
• Ascites and edema (if right-sided heart failure develops)
• Symptoms increase with exercise and pregnancy

Assessment and Diagnostic Findings

Physical exam –

• S1 - is unusually loud and may be palpable (tapping apex beat) because of increased force in closing the mitral valve [the most prominent sign]
• Opening snap - high pitched additional sound may be heard after the aortic component of the S2, followed by a low-pitched diastolic rumble due to the forceful opening of the mitral valve.

Diagnostic test -

• Chest X-ray showing left atrial enlargement
• Echocardiography is the most important test to confirm the diagnosis. It shows left atrial enlargement, thick and calcified mitral valve with narrow and "fish-mouth"-shaped orifice and signs of right ventricular failure in advanced disease
• ECG
• Cardiac catheterization
• CT scan of the chest
• MRI of the heart

Management

• No therapy is required for asymptomatic patients
• Diuretics for any pulmonary congestion or edema
• Prophylaxis of infective endocarditis
• anticoagulant administration decrease the risk for developing the arterial thrombus
• If stenosis is severe, surgery is recommended
  • Percutaneous transluminal mitral valvuloplasty
  • valvulotomy or mitral valve replacement

Aortic Regurgitation

Definition

• Also known as aortic insufficiency
• Aortic regurgitation is a disorder of the heart valve in which the aortic valve of the heart the does not close properly during ventricular diastole that causes blood to flow in the reverse direction, from the aorta into the left ventricle.
• It can be due to abnormalities of either the aortic valve or the aortic root (the beginning of the aorta).

Etiology - causes and risk factor

Acute

• Infective Endocarditis
• Trauma

Chronic

• Primary Valvular :
  • Rheumatic Fever,
  • Bicuspid Aortic Valve,
  • Marfan's Syndrome,
  • Ehlers–danlos Syndrome,
  • Systemic Lupus Erythematosus
• Causes of The Aortic Root:
  • Syphilitic Aortitis,
  • Osteogenesis Imperfecta,
  • Aortic Dissection,
  • Reactive Arthritis,
  • Systemic Hypertension

Clinical manifestation

• Heart failure symptoms, such as dyspnea on exertion, orthopnea and paroxysmal nocturnal dyspnea
• Palpitations
• Angina pectoris
• In acute cases: cyanosis and circulatory shock
• Peripheral physical signs of aortic insufficiency are –
  • high pulse pressure and the rapid decrease in blood pressure during diastole
  • large-volume, 'collapsing' pulse also known as: Watson's water hammer pulse

Assessment and Diagnostic Findings

Physical exam –

• The murmur of aortic insufficiency is typically described as early diastolic just after S₂ and decrescendo, which is best heard in the third left intercostal space and may radiate along the left sternal border.

• There may also be an Austin Flint murmur, a soft mid-diastolic rumble heard at the apical area. It appears when regurgitant jet from the severe aortic insufficiency
• S₃ may be present

Diagnostic test -

• Chest X-ray showing left ventricular hypertrophy
• ECG indicating left ventricular hypertrophy
• Echocardiogram showing dilated left aortic root and reversal of blood flow in the aorta. In longstanding disease there may be left ventricular dilatation. In acute aortic regurgitation, there may be early closure of the mitral valve.
• Cardiac catheterization assists in assessing the severity of regurgitation and any left ventricular dysfunction
• Other - CT Scan and MRI

Medical Management

• If stable and asymptomatic - conservative treatment such as –
  • low sodium diet,
  • Diuretics
  • Vasodilators
  • Digoxin
  • ACE inhibitors
  • calcium blockers
  • avoiding very strenuous activity
• Prophylaxis for endocarditis is indicated before dental, gastrointestinal or genitourinary procedures

Surgical Management

• Surgery is preferably performed before left ventricular failure occurs. It is recommended for any patient with left ventricular hypertrophy, regardless of the presence or absence of symptoms.
  • Surgery include –
    • Aortic Valvuloplasty
    • Aortic Valve Replacement

Aortic Stenosis

Definition

• Also known as Aortic valve obstruction
• Aortic Stenosis is a disorder of the heart valve in which the Aortic valve does not open fully, that obstructs blood flow from heart to aorta.

Etiology - causes and risk factor

• Degenerative calcifications - it may be caused by inflammatory changes that occur in response to years of normal mechanical stress. Risk factors for degenerative changes may - Diabetes mellitus, hypercholesterolemia, hypertension, and low levels of HDL cholesterol
• Congenital leaflet malformations of aortic valve or an abnormal number of leaflets (ie, one or two rather than three)
• (Rarely) Rheumatic fever or endocarditis. These infections may cause adhesions or fusion of the commissures and valve ring, stiffening of the cusps, and calcific nodules on the cusps.

Clinical manifestation

• Heart failure symptoms, such as –
  • Dyspnea on exertion (most frequent symptom),
  • Orthopnea and
  • Paroxysmal nocturnal dyspnea
• Angina pectoris
• Syncope, usually exertional

Assessment and Diagnostic Findings

Physical exam –

• Systolic murmur of a harsh crescendo-decrescendo type, heard in 2nd right intercostal space, radiating to the carotid arteries
• Pulsus parvus et tardus, that is, diminished and delayed carotid pulse (so-called 'apical-carotid delay').
• S4 may present
• Precordial thrill

Diagnostic test -

• Chest X-ray showing calcific aortic valve, and in longstanding disease, enlarged left ventricle and atrium
• ECG showing left ventricular hypertrophy and left atrial abnormality
• Echocardiography is diagnostic in most cases, showing left ventricular hyperthrophy, thickened and immobile aortic valve and dilated aortic root, but may appear normal if acute
• Cardiac chamber catheterization provides a definitive diagnosis, indicating severe stenosis in valve area of <0.8 cm² (normally 3 to 4 cm²). It is useful in symptomatic patients before surgery.
• Other - CT scan of the chest and MRI of the heart

Management

• No therapy is required for asymptomatic patients
• If symptomatic, treated with aortic valve replacement surgery.
• Medical therapy and percutaneous balloon valvuloplasty have relatively poor effect.
  • angina is treated with short-acting nitrovasodilators, beta-blockers and/or calcium blockers
  • hypertension is treated aggressively, but caution must be taken in administering beta-blockers
  • heart failure is treated with digoxin, diuretics, nitrovasodilators and, if not contraindicated, cautious inpatient administration of ACE inhibitors

Nursing Care

• Assess mental status (Restlessness, severe anxiety and confusion).
• Check vital signs (heart rate and blood pressure).
• Assess heart sounds, noting gallops, S3, S4.
• Assess manually peripheral pulses (with weak rate, rhythm indicated low cardiac output).
• Assess lung sounds and determine any occurrence of Paroxysmal Nocturnal Dyspnea (PND) or orthopnea.
• Monitor central venous, right arterial pressure [RAP], pulmonary arterial pressure(PAP)
• Routinely Assess skin colour and temperature (Cold, clammy skin is secondary to compensatory increase in sympathetic nervous system stimulation and low cardiac output and desaturation).
• Carefully maintain intake output and daily check weight.
• Provide Complete Bed Rest.
• Assist the patient in bathing.
• Administer oxygen as needed to prevent tissue hypoxia.
• Place the patient in an upright position to relieve dyspnea.
• Administer medication as prescribed, noting response and watching for side effects and toxicity.
• Administer stool softeners as needed(s training for a bowel movement further impairs cardiac output).
• Explain drug regimen, purpose, dose, and side effects.
• Maintain adequate ventilation and perfusion (Place patient in semi- to high-Fowler's position or supine position).
• If invasive adjunct therapies are indicated (e.g., intra-aortic balloon pump, pacemaker), maintain within prescribed protocol and prepare patient.
• Assess response to increased activity and help patient in daily activities.
• Offer diversional activities that are physically undemanding.
• Alternate periods of rest to prevent extreme fatigue and dyspnea.
• To reduce anxiety, allow the patient to express his concerns about the effects of activity restrictions on his resposibilities and routine.
• Maintain physical and emotional rest (restrict activity and provide quiet and relaxed environment).
• Monitor sleep patterns; administer sedative.
• Keep the patient's legs elevated while he sits in a chair to improve venous return in the heart.
• Keep the patient in a low sodium diet. Consult with a dietitian to ensure that the patient receives foods that he likes while adhering to the diet restrictions.
• Allow the patient to express his fears and concerns about the disorder, it's impact on his life, and any impending surgery.
• Monitor the patient's vital signs, weight, and intake and output for signs of fluid overload.
• Monitor the patient for chest pain that may indicate cardiac ischemia.
• Regularly assess the patient's cardiopulmonary function.
• Observe the patient for complications and adverse reactions to drug therapy.
• Encourage for proper Follow-up.