Tricuspid valve disease

Definitions & Key takeaways

Tricuspid valve disease or tricuspid insufficiency is a condition that affects the tricuspid valve, which is one of the four heart valves that help regulate blood flow through the heart. In tricuspid insufficiency, the tricuspid valve fails to close properly during systole, allowing the blood to flow backward into the right atrium. Tricuspid insufficiency most often results from rheumatic heart disease, which causes damage to the valve.

Signs and symptoms of tricuspid insufficiency are generally those of right-sided heart failure, such as ascites and peripheral edema. Diagnosis of tricuspid valve disease typically involves a physical exam, echocardiogram, and other imaging tests that can evaluate the structure and function of the valve. Treatment may involve medications to manage symptoms, as well as surgery to repair or replace the tricuspid valve in severe cases.

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The tricuspid valve has three leaflets—the anterior, posterior and medial or septal leaflets, and together they separate the right atrium from the right ventricle.
During systole or muscle contraction, the tricuspid valve closes, and during diastole or heart relaxation, the tricuspid valve opens and lets blood fill the right ventricle.
Tricuspid valve regurgitation happens if the tricuspid valve doesn’t close completely and blood leaks back from the right ventricle into the right atrium.
Tricuspid valve stenosis happens if the tricuspid valve can’t open completely and it becomes difficult to fill the right ventricle.
Let’s start with tricuspid valve regurgitation. Often regurgitation is due to pulmonary hypertension which causes an increase in right ventricular pressure which then dilates the tricuspid valve, allowing blood to go backward.
Another well-known cause is rheumatic heart disease, an autoimmune reaction involving the valve leaflets causes inflammation.
The chronic inflammation leads to leaflet fibrosis, which makes it so that they don’t form a nice seal and instead let blood leak through.
Another cause of tricuspid regurgitation include damage to the papillary muscles from a heart attack. If these papillary muscles die, they can’t anchor the chordae tendineae which then allows the tricuspid valve to flop back and allow blood to go from the right ventricle to the right atrium.
There are also congenital causes, like Ebstein anomaly, which is when a person is born with leaflets that are located too low and are in the ventricle rather than being between the atria and the ventricle, which makes it hard to form a nice seal.
So in all of these situations, blood flows back into the right atrium during systole or heart contraction. This movement of blood can be heard as a holosystolic murmur, because it’s possible to hear blood flowing through for the duration of systole.
There also might be Carvallo’s sign which is when the murmur gets louder with inspiration because the negative pressure in the chest brings more blood back up into the heart - and more blood makes the murmur even noisier.
Now, that extra blood that flowed backward into the atrium during systole ends up draining right back into the ventricle during diastole.
This mean’s there’s an increase in right ventricular preload. It’s kind of like if you were digging a hole and every time you shoveled some dirt out, half of it would fall back in, which is a lot of wasted work.
Eventually, to deal with this extra blood and extra work to pump it out, the right ventricle grows larger, a process called eccentric ventricular hypertrophy.
In this situation, new sarcomeres are added in series to existing ones. This remodeling or structural change in the heart stretches the annulus, or ring of the valve, letting more blood lead back and actually therefore worsens the regurgitation, a pretty vicious cycle.
This compensation works for awhile, but eventually the right ventricle might not be able to keep up and it can lead to right-sided heart failure, which causes symptoms like distended neck veins, swelling of the ankles and feet, and blood backed up to the liver causing hepatosplenomegaly.
Diagnosis is usually done with an echocardiogram, and treatment for tricuspid regurgitation is usually aimed at maintaining good fluid balance - only rarely is valve repair or replacement needed.
Alright now let’s switch gears to tricuspid valve stenosis, where the tricuspid valve doesn’t open all the way during diastole or filling.
This is most often caused by rheumatic fever, and if the tricuspid valve is affected, then the mitral and aortic valve are almost always affected as well.
In this case, as a result of inflammation, the leaflets can fuse together, called commissural fusion. When this happens, the normal tricuspid valve opening narrows down, and this makes it a lot harder for blood to flow from the right atrium to the right ventricle, and when the blood finally pushes open the fibrotic valve it makes a distinctive “snap” sound, which is followed by a diastolic rumble as blood is forced through the smaller opening.
Since it’s harder for blood to get through, blood volume and pressure increase in the right atrium, This increased right atrial volume and pressure causes it to dilate which can result in blood getting backed up into the veins.
In addition, when the right atrium dilates the muscle walls stretch and the pacemaker cells that run through the walls become more irritable, and this increases the risk of arrhythmias like atrial flutter and atrial fibrillation.
Just like regurgitation, tricuspid valve stenosis can lead to right-sided heart failure which again leads to symptoms like distended neck veins, swelling of the ankles and feet, and blood getting backed up into the liver which causes hepatosplenomegaly.
Finally, thinking about the heart in relation to other structures in the chest. If the atrium dilates and gets really large it can compress its neighbor, the esophagus, and patients might have dysphagia, difficulty swallowing solid foods.
Diagnosis is again usually done with an echocardiogram, and treatment of tricuspid valve stenosis usually involves a balloon valvuloplasty, which means that a balloon is inserted and then inflated to open the narrowed valve and allow more blood flow through it.
All right, as a quick recap, tricuspid valve regurgitation is most often due to pulmonary hypertension and is also associated with rheumatic heart disease.
On auscultation, you can hear a holosystolic murmur, and it can usually be treated with fluid balance, and over time it can lead to right-sided heart failure.
Tricuspid valve stenosis is associated with rheumatic heart disease as well, and typically also involves the mitral and aortic valves.
On auscultation, you can hear a “snap” sound, followed by a diastolic rumble, and this can be treated with balloon valvuloplasty.
Again, Tricuspid stenosis can lead to right-sided heart failure.