Introduction
Tricuspid regurgitation is a relatively common condition that results from structural abnormalities of any part of the tricuspid valve functioning and modifying parts of the tricuspid valve. Clinically relevant tricuspid regurgitation (TR) is present in more than 70 million people worldwide. Mild TR is common and usually harmless. However, moderate or severe TR can cause irreversible cardiac damage and adverse outcomes.
What Is Tricuspid Regurgitation?
TR happens when the heart's tricuspid valve does not seal completely, resulting in backward blood flow. This can change the heart's structure and result in permanent cardiac damage and associated conditions. Tricuspid valve dilation and restriction in movement of flaps of this valve due to right ventricle remodeling are the major mechanisms contributing to secondary TR. It is commonly seen in a person with late stages of heart failure due to rheumatic or congenital heart disease. Less commonly results from congenital deformity of the tricuspid valve.
How Does Tricuspid Regurgitation Affect Heart Function?
A significant degree of TR can lead to right atrial enlargement and elevation of pressure in the right atrium and jugular vein. Severe TR can lead to right ventricle dilation due to right ventricle volume overload, eventually leading to systolic dysfunction.
What Are the Types of Tricuspid Regurgitation?
1. Primary - TR is categorized as primary, where the intrinsic irregularities in the tricuspid valve apparatus are the causative factor.
2. Secondary - It is also called functional TR, which refers to the regurgitation of the tricuspid valve due to left-sided heart disease or pulmonary hypertension.
What Are the Causes of Primary Tricuspid Regurgitation?
Primary TR occurs in 15 to 30 % of cases as the result of the following etiologies;
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Congenital Heart Disorders:
Giant right atrium, Marfan’s syndrome, Ebstein’s anomaly, Septal Aneurysm, and Levotransposition of great arteries.
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Acquired Disorders of the Tricuspid Valve:
Endocarditis, carcinoid syndrome, myxomatous degeneration of the tricuspid valve, rheumatic heart disease, chest irradiation, trauma, drugs, and toxins such as Fenfluramine and Phentermine.
What Are the Causes of Secondary Tricuspid Regurgitation?
The prevalence of secondary TR increases with age. It can result most commonly from the following conditions;
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Ischemic or nonischemic cardiomyopathies.
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Aortic or mitral valvular disease.
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Pacemaker lead-induced TR.
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Cardiac defibrillator-induced TR.
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Right ventricle volume overload.
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Right ventricle cardiomyopathy.
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Chest irradiation.
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Pulmonary diseases include pulmonary emboli, left to right shunt, and chronic obstructive pulmonary disease.
What Are the Symptoms of Tricuspid Regurgitation?
A mild or moderate degree of TR is usually asymptomatic; however, TR often coexists with other cardiac disorders that may produce symptoms related to that dysfunction. However, as the disease progresses, the functions of the right ventricle also decrease, which may give rise to symptoms as given below;
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Cervical pulsation (prominent pulsating neck veins).
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Generalized weakness and fatigue.
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Abdominal bloating or fullness.
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Stomach pain.
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Decrease in appetite.
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Muscles wasting.
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Progressive weight gain.
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Painful swelling of the leg.
When to Get Help?
An individual should seek clinician care in case of feeling easily fatigued even with less work and feeling shortness of breath during day-to-day activities.
How Is the Tricuspid Regurgitation Diagnosed?
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Electrocardiogram (ECG): On ECG, right ventricle hypertrophy and right atrial enlargement, right axis deviation can be seen, which clues to TR. However, often there are no specific markers of TR on the ECG.
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Exercise Testing: It is useful in assessing exercise capacity in individuals with severe TR with no or minimal symptoms.
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Echocardiography: It is extremely useful in the evaluation of TR severity. It is also helpful in differentiating primary and functional TR. During echocardiography, TR is detected using color Doppler imaging.
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Chest Radiography: It may detect some findings related to TR as followings:
- Marked enlargement of the heart in severe cases of TR
- The elevated diaphragm in case of pleural effusions and ascites.
- Signs of pulmonary hypertension.
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Cardiac Catheterization: Elevated diastolic pressures in the right atrium and right ventricle are noted in cardiac catheterization. Right and left cardiac catheterization is performed when there is an inconsistency between the clinical features and the results of non-invasive examinations to rule out primary pulmonary or left ventricular causes of the present symptoms.
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Computed Tomographic Coronary Angiography: The cardiologist performs this to evaluate and manage TR with coronary risk factors, coronary artery disease, and cardiomyopathy.
How Is Tricuspid Regurgitation Managed?
Management of severe TR includes medical therapy, counseling regarding physical activity, review of tricuspid valve surgery, and via evaluation and treatment of the underlying condition.
A multidisciplinary cardiac team that includes a cardiothoracic surgeon, cardiologist, echocardiographer, anesthesiologist, and primary physician is required to treat high-risk individuals with severe TR properly.
According to the current American College of Cardiology, American Heart Association, and the European Society of Cardiology, heart failure guidelines management consists of the following;
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Medications: Diuretics and angiotensin-converting enzyme inhibitors may alleviate TR associated with fluid overload and chronic congestive heart failure. In addition, in individuals with liver congestion and overproduction of adrenalin by adrenal glands, kidney functions can be preserved by the addition of an aldosterone antagonists drug such as Spironolactone or Eplerenone.
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Surgical Interventions: The surgical treatment of secondary TR is still an object of debate. However, tricuspid valve repair or replacement surgically is advised for individuals with severe TR and undergoing left-sided valve surgery. In addition, surgical intervention is suggested before the onset of substantial right ventricular dysfunction to prevent and control associated symptoms in individuals who do not respond well to medical treatment and have severe TR.
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Transcatheter Tricuspid Valve Treatment: Individuals are at high risk of surgery for tricuspid valve repair or replacement due to increased morbidity or mortality. Transcatheter tricuspid valve repair or replacement is a better therapeutic option for these individuals.
Conclusion
Mild to moderate degrees of functional TR, if left untreated during left-sided valve surgery, can progress in more than 25 % of cases and result in increased cardiac failure hospitalizations, reduced long-term functional outcomes, and declined survival. The preference of treatment approaches depends on the severity of TR, causative factors, and the presence and magnitude of associated abnormalities, such as heart failure, pulmonary hypertension, and other valve conditions. In individuals with persistent or recurrent TR after left-sided heart surgery, earlier intervention is advised before right ventricular dysfunction occurs.
