Tricuspid valve stenosis

A tricuspid valve stenosis (TS) is a narrowing of the tricuspid valve located between the right atrium and the right ventricle. The difficult diastolic voiding of the right atrium leads to an increase of pressure in the right atrium with an increase of the systemic venous pressure (Daniel 2006 / Erdmann 2006).

Normally the valve opening area of the tricuspid valve is 6 cm² - 10 cm². . A stenosis of < 2.5 cm² leads to hemodynamic effects. Clinical changes can be expected from a valve opening area of < 2.0 cm² (Pinger 2019). Even at a mean diastolic pressure gradient of > 4 mmHg, stenosis leads to systemic venous congestion with formation of oedema, ascites, congested liver, etc.

The diastolic pressure gradient between the right atrium and the right ventricle increases during inspiration (caused by an increase in transvalvular blood flow) and decreases during expiration. As long as a sinus rhythm exists, the a- wave in the right atrial pressure can increase so massively that the systolic pressure maximum of the right ventricle is reached. At rest the cardiac output is low and shows only an inadequate increase under stress. As a result, the pressures in the left atrium and in the pulmonary circulation are usually normal or at best only slightly increased. A possible simultaneous mitral stenosis can thus be masked (Kasper 2015).

In the TS we do not find a differentiated classification into different degrees of severity, as is usual with Vitien. Only a heavy TS is more differentiated (Pingler 2019):

- mean pressure gradient ≥ 5 mmHg

- PHT ≥ 190 ms

- KÖF < 1.0 cm²

The TS is a rarely occurring Vitium. It occurs more frequently in women than in men. In most cases it is combined with mitral valve stenosis. And vice versa, in patients with severe mitral valve stenosis an additional hemodynamically relevant TS is found in 5 % to 10 % of cases (Kasper 2015).

The TS can be congenital or acquired.

An acquired TS can be caused by a:

• heart valve disease caused by rheumatic fever (most common cause; then mostly in combination with TI or aortic and/or mitral valve disease [Pinger 2019])
• bacterial endocarditis (Kasper 2015)
• Carcinoid syndrome
• M. Whipple
• M. Fabry
• systemic lupus erythematosus
• after methysergide medication (trade name Deseril; discontinued in Germany since 2005)
• congenital (Pinger 2019)
• For prosthetic tricuspid valve replacement
• inflammation associated with pacemaker cables (Lapp 2014)

TS alone is often asymptomatic for years.

In the further course, signs of right-sided reverse failure with upper and lower influence congestion may occur (Erdmann 2006) such as:

• Physical exertion markedly reduced (due to a drop in cardiac output at rest and on exertion).
• fatigue (Pinger 2019)
• Typically only mild dyspnea (despite significant hepatomegaly, ascites, and edema)(Kasper 2015)
• Peripheral cyanosis (occurs only in the late stages; is due to decreased cardiac output and peripheral vasodilation [Erdmann 2006]).

Since the majority of patients also have mitral stenosis, the symptoms of mitral valve stenosis may also be entirely in the foreground. Due to the increase in pressure in the left atrium, the following symptoms may occur:

• Atrial fibrillation with absolute arrhythmia (the performance of the heart is thereby reduced by about 20%); permanent atrial fibrillation often marks the turning point in the course of the disease (Kasper 2015)
• Occurrence of thrombi in the left atrium (occurs in about 40% of cases).
• Emboli in the brain, extremities, and kidneys triggered by thrombi (occur in about 20% of cases) (Herold 2018)

As a result of pulmonary congestion/pulmonary hypertension, the following symptoms may develop:

• Dyspnea, especially on exertion
• in the further course resting dyspnoea up to orthopnoea (Pinger 2019)
• nocturnal cough (so-called asthma cardiale).

A decrease in dyspnoea does not necessarily indicate a general improvement in symptoms, as the developing right heart failure with a subsequent reduction in cardiac output reduces pulmonary congestion (and thus dyspnoea). The clinical picture is then dominated by right heart failure with low output syndrome or reverse failure (Pinger 2019):

• Hemoptysis (due to increased pulmonary arterial pressure, ruptures of the broncho- venous vessels occur; however, these hemoptyses rarely end lethally [Kasper 2015]).
• Hemoptysis with coughing up of "cardiac defect cells" (pulmonary macrophages containing hemosiderin) in the sputum (Herold 2018)

As a result of right heart failure, the following symptoms may occur:

• Visible venous congestion in the neck and under the tongue due to increased venous pressure.
• Congestive liver
• Congestive kidneys
• Proteinuria
• Edema in the dependent parts of the body (Herold 2018).

Due to the decreased cardiac output, there may be:

• general reduction in performance
• Peripheral cyanosis (so-called facies mitralis with reddish-cyanotic cheeks) (Herold 2018).

Due to the dilated left ventricle may occur:

• Hoarseness (due to compression of the recurrent laryngeal nerve )
• Dysphagia (Pinger 2019)

Chest X-ray: Radiological changes do not necessarily occur in TS. Even in hemodynamically severe TS, they may still be absent.

However, if radiological changes are detectable, the right atrium is widened to the right on the p.a. image. image, the right atrium is widened to the right. It may be enlarged to such an extent that the image of cardiomegaly is found. Due to the dilated and pulsating superior vena cava and azygos vein, the mediastinal shadow may be widened to the right. Very rarely, calcifications of the tricuspid valve may be seen on fluoroscopy (Erdmann 2006).

Echocardiography: Echocardiography usually shows:

• a thickening of the tricuspid valve with doming in diastole (Kasper 2015).
• Dilatation of the right atrium
• Dilatation of the vena cava (Pinger 2019).

The mean pressure gradient and the pressure half-life (also called PHT and T ½, respectively) should be determined (Kasper 2015).

One speaks of a high-grade tricuspid stenosis if

• the valve opening area is < 1.0 cm2 or
• the pressure half-life is > 190 ms (Kasper 2015)
• Mean pressure gradient ≥ 5 mmHg (Kasper 2015).

Transthoracic echocardiography: Transthoracic echocardiography can additionally provide the following information:

• Indications of the severity of coexisting tricuspid regurgitation.
• size and function of the right ventricle can be determined
• function and morphology of the mitral valve
• size and function of both ventricles
• via pulmoarterial pressure (Kasper 2015)

Right and left heart catheterization: It is not routinely necessary to perform coronary angiography to assess TS (Kasper 2015). However, a right heart catheter is generally required to accurately quantify the degree of stenosis. Due to the rheumatic genesis of the stenosis, this is usually performed as part of a right/left heart catheterization (Lapp 2014). The following can be detected during the examination:

• an increase of the a-wave in the right atrial pressure (this can increase to the point that the systolic pressure maximum of the right ventricle is reached)
• the pressure in the left atrium is usually normal (due to the low cardiac output)
• the pressure in the pulmonary stromal pathway is also overwhelmingly normal (also due to the low cardiac output) (Kasper 2015)

For accurate quantification of the severity of the stenosis, pressure measurement should in any case be performed simultaneously with 2 catheters (in the right atrium and right ventricle), otherwise small diastolic pressure differences can easily be missed (Lapp 2014). We speak of tricuspid stenosis, from a gradient of 2 mm. The coefficient of flow is calculated according to Gorlin (Pinger 2019).

Inspection:

• Early symptoms include positive hepatojugular reflux (Erdmann 2006).
• In the further course then occur:
  • Hepatomegaly
  • splenomegaly (in severe cases)
  • Edema
  • Anasarca
  • Ascites
  • Congestion of the jugular veins (Kasper 2015).

Auscultation: Auscultation findings are best heard in the 4th-5th ICR above the sternum or parasternal left (Erdmann 2006).

• Presystolic crescendo-decrescendo murmur (This murmur is caused by atrial contraction . It ends just before the 1st heart sound. The punctum maximum is located in the 4th - 5th ICR parasternal left).
• In higher grade TS, an accentuated 1st heart sound with wide fission may be auscultated at the left lower sternal border (Erdmann 2006).
• Occasionally, a tricuspid opening tone is heard (it follows approx. 0.06 sec after closure of the pulmonary valve [Kasper 2015]). If mitral valve stenosis is present at the same time, this tone can be auscultated parasternally on the left after the mitral opening tone (Erdmann 2006).
• The main auscultatory finding is a mesodiastolic low-frequency murmur with punctum maximum in the 4th-5th ICR parasternal left or above the xiphoid process (Kasper 2015). There is an amplification of the murmur during inspiration (the amplification during inspiration distinguishes TS well from mitral valve stenosis). In addition, the murmur is amplified in the right lateral position and when both legs are raised. During expiration and Valsalva maneuver, there is attenuation of murmur due to corresponding decrease in flow (Kasper 2015).

ECG

• P- dextrocardiac (particularly high and peaked P- waves in lead II).
• positive P- waves in V1 (Kasper 2015)
• Possibly atrial fibrillation (but very rare in isolated TS [Erdmann 2005]) (Pinger 2019).
• AV block of I. Grade may occur (Erdmann 2006).

In patients with clinical right heart failure and the presence of mitral stenosis, concomitant TS should always be considered in the absence of signs of right heart hypertrophy on ECG (Kasper 2015). If the ECG shows a sinus rhythm, a P dextroatriale without widened P wave in II, III and aVF with simultaneously accentuated first part of the P wave in V1 and V2 and additionally missing signs of a right ventricular hypertrophy speaks for an isolated TS (Erdmann 2006).

Mitral stenosis (Bob 2001)

Both conservative and surgical treatment options are available.

Conservative therapy:

Patients with a pressure gradient of 3 - 9 mmHg should only be treated conservatively, as this has been shown to have a benign course so far.

Patients with heart failure can receive the following medication:

• Diuretics (thiazide, spironolactone or a loop diuretic)
• Digitalis exclusively for atrial fibrillation
• However, ACE inhibitors and ATII blockers are contraindicated (Herold 2018)
• Salt restriction is recommended in existing heart failure (Kasper 2015)
• Reduction of physical strain (Pinger 2019)
• Antacids for congestive gastritis (Erdmann 2006)

When administering medication orally, however, it should be noted that the sometimes considerable congestion in the mesenteric region can lead to problems in resorption of the medication. In this case an intravenous administration should be performed (Erdmann 2006).

In the case of newly occurring atrial fibrillation, which in most cases is caused by the simultaneously existing mitral stenosis, a pharmacological or electrical cardioversion should be performed. The patient must have been anticoagulated in the therapeutic area for at least 3 weeks. If cardioversion is required more quickly, heparinization and the exclusion of thrombi in the left atrium by means of transesophageal echocardiography is recommended (Kasper 2015). The chances of success of cardioversion are low in

• a concurrent high grade MS
• distinct dilatation of the left ventricle
• Atrial fibrillation lasting longer than 1 year

However, if a sinus rhythm is restored after cardioversion, in the majority of cases it cannot be maintained over the long term (Kasper 2015).

Patients with moderate to severe symptoms should, however, undergo surgical therapy. The indications for this surgical treatment are:

• mean diastolic gradient > 4 mmHg
• Flap opening area < 1.5 cm² - 2.0 cm² (Kasper 2015)

After ESC 2012 and ACC / AHA 2014 the following recommendation results:

Class I:

• symptomatic patients with severe TS
• Patients with severe TS with pending surgery of a left-sided valve (Pinger 2019)

Since a patient with TS is primarily characterized by signs of a clear venous congestion, patients should be brought into the best possible condition preoperatively with:

• Saline restriction
• Diuretics
• Bed rest

As soon as the liver function has improved, the risk of surgery is reduced, especially the risk of bleeding (Kasper 2015).

The surgery itself should be performed as a combined procedure together with a mitral valve reconstruction. In most cases, hemodynamically effective tricuspid insufficiency exists in addition to TS. Primarily, valve reconstruction is recommended. However, if this is not possible, the valve must be replaced.

A balloon valvuloplasty is performed only very rarely. However, if it does, it is only performed in the case of isolated tricuspid stenosis without evidence of concomitant insufficiency (IIb recommendation according to ESC 2012 and ACC / AHA 2014 [Pinger 2019]).

In a meta-analysis, the survival of patients with bioflaps and mechanical valves shows no differences, but the mechanical valve is particularly susceptible to thromboembolic complications in tricuspid position. Therefore, mechanical valves are only used in exceptional cases (Kasper 2015).

The pressure load with concentric hypertrophy caused by stenosis of the valves is much more stressful for the heart and therefore has the less favourable prognosis (Herold 2018).

However, if the TS is isolated, the resulting secondary damage with insufficiency of the organs does not lead to a relevant reduction of life expectancy. Prognostically, the accompanying vitae are more important (Erdmann 2006).

However, since isolated tricuspid stenosis occurs only very rarely, prognostic data are unfortunately scarce (Pinger 2019).

Patients with valve reconstruction or prosthetic heart valve have a significantly increased risk of endocarditis. The post-procedural bacteremia frequency, e.g. after tooth extractions in gingivitis, is up to 90%. For this reason, postoperative endocarditis prophylaxis is necessary for certain procedures. The standard therapy is administered as a single dose approx. 30-60 minutes before the procedure, e.g. amoxicillin or ampicillin 2 g orally or i.v., or in the case of penicillin allergy clindamycin 600 mg also orally or i.v. (Pinger 2019).

For further details see Endocarditis prophylaxis

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