Right heart valve disease

The right side of the heart contains 2 valves, the tricuspid valve and the pulmonary valve. Let’s discuss the diseases affecting both of these…

TRICUSPID VALVE DISEASE

🦴 Anatomy

The tricuspid valve is an atrioventricular valve between the right atrium and right ventricle. It is located at the 4th intercostal space, behind the sternum. It is lying almost vertically (opening to the right).

It can be auscultated at the 5th ICS, left sternal border.

It normally opens during diastole, allowing the right ventricle to fill, and closes during systole (preventing the back flow of blood into the right atrium).

In this CCC will be discussing tricuspid stenosis and tricuspid regurgitation.

TRICUSPID STENOSIS

Pathophysiology

Tricuspid stenosis is a relatively rare conditions caused by a narrowing of the tricuspid valve which increases the pressure gradient across the valve during diastolic filling of the right ventricle.

It often occurs as a late complication of rheumatic heart disease (RHD):

In RHD, molecular mimicry results in antibody reactivity to antigens of group A streptococcus (GAS) as well as our heart valves. It causes fibrin deposition on the leaflets of the valves → fusion of the valve commisures (the location where the valves meet) which results in thickening and fusion of the chordae tendinae which impairs the ability of the valve to open sufficiently.

Tricuspid stenosis usually is not occurring in isolation. It often occurs concomitantly with mitral and aortic stenosis.

It rarely occurs without RHD, but some rarer causes include:

1. Carcinoid syndrome
2. Infective endocarditis
3. Congenital disease of the tricuspid valve

😷 Presentation

• Dyspnoea - this is usually due to concomitant mitral stenosis.
• Raised JVP with a prominent a wave - the a wave represents atrial contraction. Increased atrial pressure causes pulsation of the JVP and a more prominent a wave. In patients with AF: there is a raised JVP without an a wave.

🔍 Investigations

🥇The first-line and diagnostic investigation is a transthoracic echocardiogram with Doppler.

🧰 Management

Management depends on the aetiology of the disease:

• Congenital disease of the tricuspid valve → valve replacement is the management of choice.
• Alprostadil - should be given preoperatively.
• Aspirin - antiplatelet therapy should be given postoperatively.

• Carcinoid heart disease
• Fluid and sodium restriction is first-line
• Loop diuretic - furosemide
• Somatostatin analogue (octreotide) - inhibiting growth hormone and the effects of carcinoid disease on the heart.
• Valve replacement or balloon dilatation (valvuloplasty)
• Rheumatic fever
• Fluid and sodium restriction is first-line
• Loop diuretic - furosemide is given to manage heart failure.
• In severe cases valve replacement may be needed.
• Infective endocarditis - antibiotics and valve replacement (if there are indications for surgery). However, if there are no indications for surgery, antibiotics alone is sufficient.

What are the indications for surgery?

Progressive HF, severe valve obstruction, perivalvular abscess, non-candidal fungal infection, pseudomonas infection, persistent bacteraemia, candidal endocarditis, large vegetation’s (>10mm).

TRICUSPID REGURGITATION

Pathophysiology

As we mentioned previously, the tricuspid valve needs to close during ventricular systole to prevent the passage of blood back through into the right atrium. However, with tricuspid regurgitation, the valve fails to close and blood passes into the right atrium → increased right atrial pressure. Blood will also pass into the venae cavae → increased venous pressure.

So what can cause tricuspid regurgitation?

The causes can be divided into valvular causes (primary tricuspid regurgitation) or non-valvular causes (secondary tricuspid regurgitation). This includes:

1. Right ventricular dilatation - prevents total closure of the tricuspid valve as the ventricle is stretched.
2. Rheumatic heart disease
3. Infective endocarditis - this is most prominent in IV drug users.
4. Carcinoid syndrome
5. Congenital disease - such as ASDs or Ebstein anomaly.
6. Pulmonary hypertension - in patients with COPD, for example.
7. Right ventricular infarction

🫀

Ebstein anomaly

A congenital defect characterised by a low lying tricuspid valve which results in an abnormally large right atrium and an abnormally small right ventricle. This is known as atrialisation of the right ventricle, as the atrium encroaches on the ventricle.

The causes of Ebstein anomaly include lithium exposure in-utero. This is why it is important that lithium is not taken during the first trimester of pregnancy.

⚠️ Risk factors

😷 Presentation

Patients with tricuspid regurgitation tend to be asymptomatic, even with severe regurgitation. However, they may present with signs of heart failure, such as:

🔍 Investigations

🥇The first-line and diagnostic investigation is a transthoracic echocardiogram or transoesophageal echocardiogram.

🧰 Management

The first-line management involves treatment of underlying cause.

• If there is fluid overload due to heart failure, we can give diuretics.
• If unresponsive to medical treatment, there are surgical options:
1. Ring annuloplasty - strengthens the annulus (ring around the valve).
2. Valve replacement

PULMONARY VALVE DISEASE

🦴 Anatomy

The pulmonary valve is a semilunar valve that is located between the right ventricle and our pulmonary trunk. It is the most superior of the 4 valves, located at the 3rd ICS at the 3rd costosternal junction.

We auscultate it over the left sternal border at the level of the 2nd intercostal space.

It is closed during diastole, but opens during systole when the pressure becomes higher in the ventricles, allowing the passage of blood from the right ventricle → lungs.

PULMONARY STENOSIS

Pathophysiology

This is the narrowing of the pulmonary valve → increased valvular pressure gradient during systole (>10mmHg) which leads to a failure of the valve to open.

It is mostly due to congenital causes such as:

1. Turner’s syndrome (45 XO) - however, more associated with aortic dissection and aortic stenosis.
2. Noonan’s syndrome
3. William’s syndrome
4. Tetralogy of Fallot (pulmonary stenosis, right ventricular hypertrophy, ventricular septal defect, and overriding aorta).
5. Congenital rubella infection

But it may also occur with rheumatic heart disease and carcinoid syndrome.

😷 Presentation

Other features that we may see are:

• Prominent a waves in the jugular veins - similar to what we see in tricuspid stenosis.
• Widely split S2 - the blood from the ventricles will take longer to pass through the narrow valve and as a result the closure of the valve also takes longer.
• Inaudible or soft P2
• Right ventricular dilatation due to pulmonary stenosis → right ventricular heave, tricuspid regurgitation and peripheral signs of right-sided heart failure (such as peripheral oedema and ascites).

🔍 Investigations

🥇The first-line and diagnostic investigation is a transthoracic echocardiogram or transoesophageal echocardiogram. It is also good at assessing the severity of the issue.

🧰 Management

First-line management for asymptomatic patients is to simply observe without intervention.

PULMONARY REGURGITATION

Pulmonary regurgitation is another rare heart disorder. It occurs when there is back flow of blood from the pulmonary artery into the right ventricle during ventricular diastole as the valve fails to close.

It may occur due to the following causes:

1. Pulmonary hypertension and dilated pulmonary arteries - for example in COPD.
2. Mitral stenosis - this causes blood to back up in to the pulmonary veins → pulmonary arteries → pulmonary regurgitation.
3. Infective endocarditis
4. Congenital valvular heart disease

⚠️ Risk factors

😷 Presentation

Once again it is usually asymptomatic.

🩺

Auscultation findings:

• Early diastolic murmur - this is heard loudest over the left sternal border at the 2nd ICS. It is loudest during inspiration
• When pulmonary regurgitation occurs due to pulmonary hypertension due to mitral stenosis, we may hear what is known as a Graham Steel murmur. This is a soft, blowing, decrescendo early diastolic murmur caused by pulmonary hypertension.

Other clinical signs may relate to pulmonary hypertension, such as:

1. Dyspnoea
2. Decreased exercise tolerance