Heart Valve Regurgitation

What Is Regurgitation?

Regurgitation is the backflow of the blood in the opposite direction due to improper closure of the heart valves. There are four types depending on which of the valves are affected.

1. Mitral regurgitation.

2. Aortic regurgitation.

3. Tricuspid regurgitation.

4. Pulmonary regurgitation.

Why Does It Occur?

It occurs spontaneously in some, while in others, there is a gradual onset.

1. Acute:

• Heart attack.

• Endocarditis.

2. Chronic:

• Mitral valve prolapse.

• Rheumatic heart disease.

• Uncontrolled hypertension.

1) Mitral Regurgitation:

Mitral regurgitation is called the backflow of blood from the left ventricle to the left atrium during systole.

Causes of Mitral Regurgitation-

1. Chronic Mitral Regurgitation:

• Rheumatic fever.

• Mitral valve prolapse.

• Infective endocarditis (damage to valve).

• Ischemic heart disease.

• Dilated cardiomyopathy (dilatation of ventricle or mitral valve ring).

• Connective tissue diseases.

1. Acute Mitral Regurgitation:

• Infective endocarditis.

• Myocardial infarction (papillary muscle rupture).

• Trauma.

Pathophysiology-

Mitral regurgitation leads to gradual dilatation of the left atrium. However, chronic volume overload leads to left ventricular dilatation. Eventually, the pressure in the left ventricle and left atrium rises, leading to breathlessness and pulmonary congestion. On the contrary, there is the sudden elevation of left atrium pressure in acute mitral regurgitation, causing severe pulmonary edema.

Clinical Manifestations-

The main symptoms of chronic mitral regurgitation are,

• Feeling overtired (Fatigue).

• Shortness of breath during exercise (Exertional dyspnea).

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• Breathing discomfort on lying down flat (Orthopnea).

• Thromboembolic events (less common).

The symptoms of acute severe mitral regurgitation commonly present with,

• Acute pulmonary edema.

• Excess abdominal fluid.

The clinical signs of mitral regurgitation are,

1. Atrial fibrillation (irregular pulse).

2. Systolic thrill in mitral area.

3. Auscultation:

1. Soft first heart sound.

2. Third heart sound.

3. Pan systolic murmur in mitral area.

1. Raised pulmonary capillary pressure.

2. Raised jugular venous pressure.

3. Tender hepatomegaly.

4. Bilateral pitting pedal edema.

5. Ascites.

Investigations-

1. ECG may reveal evidence of left atrium and left ventricular enlargement, right ventricular hypertrophy, and atrial fibrillation.

2. Chest x-ray shows findings suggestive of the left atrium and left ventricle enlargement and pulmonary congestion.

3. Echocardiography reveals structural abnormalities of the valves, size of cardiac chambers, pulmonary artery pressure, ventricular dysfunction, and presence of thrombi.

Doppler echocardiography is needed to detect and estimate mitral regurgitation. Transesophageal echocardiography provides better information than transthoracic echocardiography.

1. Cardiac catheterization is used to assess the severity of mitral regurgitation, to detect associated valvular lesions and coronary artery disease.

Treatment-

Medical Treatment of Mitral Regurgitation:

1. Restriction of physical activities that cause fatigue and breathlessness.

2. Sodium restriction and diuretics are used to reduce pulmonary congestion.

3. Digoxin is given to control ventricular rate in patients with atrial fibrillation and to improve ventricular systolic function.

4. Vasodilators like ACE inhibitors are given in chronic mitral regurgitation to reduce regurgitation and improve forward output.

5. Intravenous nitroprusside or nitroglycerine is useful in acute mitral regurgitation.

6. Oral anticoagulant (Warfarin) is given to patients with a history of thromboembolic events or to those with atrial fibrillation.

7. Prophylaxis should be given to all patients to prevent rheumatic fever.

8. Prophylaxis for infective endocarditis should be given prior to procedures.

Surgical Treatment for Mitral Regurgitation:

• Mitral Valve Repair or Mitral Valve Replacement-

Patients who are initially on medical therapy are watched for symptomatic worsening and for radiological evidence of progressive cardiac enlargement or deteriorating cardiac function. In this case, surgery is indicated. Surgery includes repair or replacement of the mitral valve.

• Acute Mitral Regurgitation-

Acute mitral regurgitation due to endocarditis, myocardial infarction, and trauma often require emergency surgery. Prior to surgery, patients are stabilized by vasodilators or intra-aortic balloon counterpulsation, which reduces regurgitation by lowering systemic vascular resistance.

2) Aortic Regurgitation:

Aortic regurgitation is called the backflow of blood from the aorta through an incompetent aortic valve into the left ventricle during diastole. It may be either due to valvular involvement or dilatation of aortic root or both.

Causes of Aortic Regurgitation-

• Rheumatic fever.

• Endocarditis.

• Trauma.

• Congenital bicuspid aortic valve.

• Syphilis.

• Ankylosing spondylitis.

• Aortic dissection.

• Marfan syndrome.

• Hypertension.

• Syphilis.

• Ankylosing spondylitis.

Pathophysiology-

There is leakage of aortic valves in aortic valve regurgitation. The valves of the heart help the blood to flow out of the heart to the body. Usually, blood flow into the left ventricle is stopped by the aortic valves. But during aortic valve regurgitation, there is dilatation and hypertrophy of the left ventricle, making some blood leak back into the valve when the heart relaxes.

Clinical Manifestations-

• The patients remain asymptomatic for years.

• Palpitations, particularly on lying down, are generally an early symptom.

• Later on, patients present with dyspnea on exertion followed by orthopnea.

• Angina may also occur frequently in severe aortic regurgitation.

• The presentations in acute severe aortic regurgitation are,

1. Pulmonary edema.

2. Tachycardia.

3. Cold extremities.

4. Hypotension.

5. Cyanosis.

The clinical signs of aortic regurgitation are,

• Collapsing pulse.

• Dancing carotids (prominent carotid arteries).

• Quincke’s sign (alternate flushing and paling of skin at the root of the nail on pressure).

• A pistol shot sound over femoral arteries (Traube’s sign).

• Duroziez sign (to and fro murmur over femoral artery when it is compressed).

• De Musset’s sign (head nodding with the pulse).

• Increased pulse pressure (low diastolic pressure).

• Hill’s sign - Systolic blood pressure in lower limbs is higher (>20 mm Hg) than in upper limbs.

• Laterally displaced apex beat.

• Diastolic thrill at the left sternal border.

• High pitched blowing early diastolic murmur.

• Other murmurs include ejection systolic murmur at the aortic area radiating to the carotid artery and low pitched mid-diastolic murmur over the mitral area (Austin Flint murmur).

• Basal crackles in lungs.

• Edema.

• Hepatomegaly.

Investigations-

1. ECG shows evidence of left ventricular hypertrophy and ST-T changes.

2. Chest x-ray reveals abnormal enlargement of the heart (cardiomegaly) and aortic root dilatation. Features of pulmonary congestion may be present.

3. Echocardiography may reveal structural abnormalities of the valves, size of cardiac chambers, pulmonary artery pressure, ventricular dysfunction, and presence of thrombi. Doppler echocardiography is needed to assess the severity of aortic regurgitation.

4. Cardiac catheterization is mainly required to detect the presence of coronary artery disease.

Treatment-

Medical Treatment of Aortic Regurgitation:

1. Strenuous physical activities should be avoided.

2. Sodium restriction and diuretics are advised in the presence of congestive heart failure.

3. Digoxin and vasodilators (ACE inhibitors) are given to improve ventricular systolic function in patients with left ventricular failure. Long-acting Nifedipine has been found to delay the need for operation.

4. An oral anticoagulant (Warfarin) is given if it is atrial fibrillation.

5. Prophylaxis for infective endocarditis should be given prior to procedures. Recent guidelines recommend prophylaxis only if there is a prior history of endocarditis.

6. Nitroprusside or inotrope is given in acute aortic regurgitation to stabilize the patient before surgery.

7. Treatment of precipitating or underlying causes (syphilis, endocarditis) should be commenced.

Surgical Treatment for Aortic Regurgitation:

• Aortic Valve Replacement or Aortic Root Repair-

All symptomatic patients with chronic aortic regurgitation should be considered for aortic valve replacement. However, surgery may also be advisable in asymptomatic patients who show evidence of abnormal enlargement of the heart or deteriorating left ventricular function. Repair of aortic root abnormalities and aortic valve replacement should urgently be performed in the patient with acute aortic regurgitation. Vasodilators or inotropes may stabilize patients before surgery.

3) Pulmonary Regurgitation:

1. It is usually associated with dilatation of the pulmonary artery due to pulmonary hypertension causing the valve to not close properly, with leakage of blood back into the heart.

2. It may complicate mitral stenosis as it is difficult to distinguish from aortic regurgitation (Graham Steell murmur) because of early diastolic murmur.

3. Trivial pulmonary regurgitation is a frequent finding in normal individuals and has no clinical significance.

4) Tricuspid Regurgitation:

Tricuspid regurgitation is common and is most frequently a result of right ventricular dilatation. It occurs due to improperly formed right atrium and ventricle, making the blood flow back into the right atrium.

Causes of Tricuspid Regurgitation-

Primary Causes:

1. Rheumatic heart disease.

2. Endocarditis, particularly in injection drug users.

3. Ebstein’s congenital anomaly.

Secondary Causes:

1. Right ventricular dilatation due to chronic left heart failure (functional tricuspid regurgitation).

2. Right ventricular infarction.

3. Pulmonary hypertension.

Symptoms of Tricuspid Regurgitation-

1. Tiredness.

2. Edema.

3. Hepatic enlargement due to venous congestion.

4. The most prominent sign is a ‘giant’ v wave in the jugular venous pulse (a cv wave replaces the normal x descent).

5. Pansystolic murmur at the left sternal edge.

6. Pulsatile liver.

Investigations-

1. Echocardiography may reveal dilatation of the right ventricle. If the valve has been affected by rheumatic disease, the leaflets (tissue flaps of the valve) will appear thickened, and, in endocarditis, vegetations (bacterial growth on heart valves) may be seen.

2. Ebstein’s anomaly is a congenital abnormality of the tricuspid valve, where the valve between the right atrium and ventricle is improperly formed, with consequent enlargement of the right atrium. It is commonly associated with tricuspid regurgitation.

Treatment-

1. Tricuspid regurgitation due to right ventricular dilatation often improves when the cause of the right ventricular overload is corrected, with diuretic and vasodilator treatment.

2. Patients with a normal pulmonary artery pressure tolerate isolated tricuspid reflux well.

3. Valves damaged by endocarditis do not usually need to be replaced.

4. Patients undergoing mitral valve replacement, who have tricuspid regurgitation due to marked dilatation of the tricuspid annulus, benefit from valve repair with an annuloplasty ring to bring the leaflets closer together.

5. People with rheumatic damage may require tricuspid valve replacement.