What is Pericardial Calcification?
The pericardium, a part of your heart, is normally 1 to 2 millimeters thick. It’s made up of an outer layer and an inner layer. The inner layer is split into two parts – the epicardium (the heart’s own coating or skin), and the parietal layer (interior wall layer). There is a small space between these layers which holds about 15 to 35 milliliters of lubrication fluid. The job of the pericardium is to keep the heart in place, make sure the heart doesn’t over-expand, and help it to fill with blood smoothly. It doesn’t normally have any calcium deposits – if it does, it could be a sign of inflammation or a more serious problem. This condition, called pericardial calcification, is usually discovered when doing a scan of the chest.
In many cases, pericardial calcification doesn’t cause symptoms and is found accidentally during a chest scan. In some cases, however, symptoms can occur if the pericardium becomes stiff due to the calcification. However, it’s important to remember that even with a disease called constrictive pericarditis (which causes the pericardium to tighten and harden), pericardial calcification may not be present in up to 20% of cases. In other cases, pericardial calcification could be present even if there are no symptoms. Interestingly, some reports have shown constrictive pericarditis developing after a heart transplant, which is unexpected, as the new heart is believed to be free of any pericardial tissue.
What Causes Pericardial Calcification?
Pericardial calcification is a condition that happens as a result of inflammation, hardening, and death of tissues. The common reasons for such inflammation could be viral infections, exposure to radiation in the chest, or after heart surgery. In the past, tuberculosis was a major cause of this condition in the US, accounting for nearly half of the cases. But now, it’s more common in developing countries. Other conditions that can cause pericardial calcification include uremic pericarditis (a type of heart disease that occurs in people with poor kidney function), injuries, cancer, and diseases related to rheumatism and connective tissues. Another known reason for this condition is exposure to asbestos. However, interestingly enough, in over half of the cases of pericardial calcification, the exact cause remains unknown.
Risk Factors and Frequency for Pericardial Calcification
Pericardial calcification is a condition that doesn’t always show symptoms, so we aren’t exactly sure how common it is. However, we do know it’s more likely to happen after trauma, infections of the pericardium (the sac around the heart), and in the presence of specific diseases like cancer and connective tissue disorders.
The rate of occurrence is different depending on the specific type of constrictive pericarditis (a condition where the heart’s sac hardens and restricts the heart’s function). For instance, idiopathic (unknown cause) and viral constrictive pericarditis appear in close to 1 out of every 1000 people per year in a study of 500 patients. In contrast, the rate was significantly higher in populations with connective tissue disease, cancer, tuberculosis, and purulent (infected) pericarditis – 4.4, 6.33, 31.65, and 52.74 out of 1000 people per year, respectively.
Tuberculous pericarditis, specifically caused by tuberculosis bacteria, occurs in about 1% of all tuberculosis cases and 1 to 2% of lung tuberculosis instances. Typically, this type of tuberculosis is subacute, meaning that calcifications of the pericardium (hard, calcified areas in the sac around the heart) are rare.
A study showed that pericarditis with calcifications tends to be more common in men.
Signs and Symptoms of Pericardial Calcification
Pericardial calcification, or the buildup of calcium in the sac surrounding the heart, is often without symptoms. However, if the condition starts affecting the heart rate and blood flow, or leads to constrictive pericarditis (inflammation and hardening of the sac), symptoms can occur. These signs often resemble those of a failing right heart or low output states, including:
- Breathlessness during regular activities
- Difficulty breathing when lying flat
- Shortness of breath or discomfort when bending forward
- Constant tiredness
Among these, difficulty in breathing during exercise and swelling in the lower limbs are the most frequent symptoms. Physical examination might reveal enlarged liver, fluid buildup in the abdomen, swelling in the legs, increased blood flow in the liver when pressure is applied to the abdomen, Kussmaul’s sign (rise in neck veins during inspiration), high neck veins with particular patterns in their pulse, and an abnormal decrease in blood pressure upon inspiration. In severe cases, unexplained weight loss can also be observed.
Additionally, irregular heartbeats, specifically atrial fibrillation and atrial flutter, are observed more frequently in patients with constrictive pericarditis accompanied by pericardial calcification.
Testing for Pericardial Calcification
Pericardial calcification, a condition where there are calcium deposits in the sac around the heart, can affect heart functionality. It’s important to look for both the physical signs of this calcification and the impact it’s having on the heart. Doctors can identify the presence of pericardial calcification using a type of X-ray called a chest radiograph, but this doesn’t always catch it. Certain tests can show increased levels of liver enzymes and creatinine, as well as an increase in B-type natriuretic peptide and N terminal pro-brain natriuretic peptide, which can help distinguish pericardial calcification from other heart conditions.
A specific type of scan called a CT scan can give doctors a clearer picture of the heart and surrounding area. Normally, the sac around your heart (the pericardium) should be less than 2mm thick when seen on a CT scan. If it appears to be more than 4mm thick, this suggests constrictive pericarditis, a condition where this sac becomes stiff and constricts the heart. However, even people with a normal thickness pericardium can have pericardial calcification and develop constrictive pericarditis. If present, pericardial calcification usually affects the parts of the pericardium closest to the diaphragm and in front of the heart, with less common involvement of the tip and left upper chamber of the heart.
A bone scan called ’99m Tc-methylene diphosphonate’ can also identify pericardial calcification. This scan may be used if the CT scan is proving complex.
To understand the effect that pericardial calcification is having on the heart’s function, doctors often use a kind of ultrasound test called two-dimensional (2-D) echocardiography and tissue Doppler imaging. This test can show abnormal motion of the wall that separates the two main pumping chambers of the heart, changes in how the two sides of the heart are interacting with each other, and signs of a full inferior vena cava (the vein that carries deoxygenated blood from the lower half of the body back to the heart). The main difference doctors could observe will be around the ring around the entrance to the left bottom chamber of the heart (the mitral annulus). These observations can be critical in diagnosing constrictive pericarditis.
Doctors may use a type of imaging called cardiac MRI to both determine the thickness of the pericardium and view the effects of the condition on the heart. Although MRI may not be as effective as CT scans at detecting pericardial calcification, it can also provide information about the extent of inflammation and scarring, which can help determine the progression of the disease and predict who may develop conic pericarditis, a more long term condition.
In certain cases where the diagnosis is unclear, an invasive investigation using cardiac catheterization may be carried out. This involves threading a long, thin tube (a catheter) into a blood vessel to reach your heart and measure its pressures.
In the past, doctors would sometimes take a sample of heart tissue (an endomyocardial biopsy) to differentiate constrictive pericarditis from other heart conditions. However, this has been found to not be particularly effective.
Treatment Options for Pericardial Calcification
If your heart’s outer lining, the pericardium, becomes stiff and hard — a condition known as constrictive pericarditis — it may not cause any symptoms if the pericardium also develops deposits of calcium. In such a scenario, there’s no need for treatment.
However, if the condition is in its subacute (not acute but not quite chronic) phase and there’s underlying inflammation involved, your doctor may prescribe anti-inflammatory treatments. These may include medicines like colchicine, corticosteroids, and non-steroidal anti-inflammatory drugs, or NSAIDs. While these anti-inflammatory agents may not reverse the already-hardened or calcified tissue, they aim to slow the progression of inflammation and stop further scarring.
To best determine who might benefit from this anti-inflammatory therapy, cardiac MRI, a type of heart imaging test using magnetic waves, can often help. It can visualize both the scarred and inflamed areas simultaneously, offering your doctor valuable information.
In the early stages of constrictive pericarditis, doctors may prescribe diuretics — medications designed to help your body get rid of unneeded water and salt — to relieve fluid buildup in your lungs and rest of the body. However, doctors must be extra careful, as these drugs could lead to a corresponding drop in the amount of blood pumped out by your heart if they cause too much decrease in your blood volume.
Surgical removal of the pericardium, known as a pericardiectomy, is the primary treatment option for constrictive pericarditis and can potentially cure it. This surgery generally has a high success rate of 70-80%, but it’s noteworthy that it also comes with a high risk of complications during or immediately after the surgery, with a mortality rate of 5 to 10%.
The risk of complications after surgery tends to be influenced by the severity of heart failure symptoms, as measured by something called the New York Heart Association heart failure class. Patients in Class I and II, or those with less severe symptoms, often fare better post-surgery than those in Class III and IV, who have more severe symptoms. However, the presence and extent of pericardial calcification typically do not affect outcomes after surgery.
What else can Pericardial Calcification be?
When checking for Constrictive Pericarditis (CP), which is a condition related to heart, doctors will first look for a hard shell-like substance on the heart’s outer surface found through imaging tests. Other less-common types of CP also need to be taken into consideration:
- Transient constriction: A type of constriction that can be cured with anti-inflammatory medicines.
- Effusive constrictive pericarditis: This appears in patients with a cardiac fluid build-up problem and becomes evident immediately after a procedure to remove fluid from the heart’s lining.
- Occult constrictive pericarditis: It reveals itself after a fluid challenge test.
In addition to these types, doctors also consider if the hardness on the heart’s outer lining could be due to scars from repeated inflammation of the heart’s outer lining. Moreover, there are certain conditions which closely resemble CP and clinicians would need to rule them out. These include restrictive cardiomyopathy, a heart disorder due to stiffness of the heart muscles and severe leakage from the tricuspid heart valve.
What to expect with Pericardial Calcification
Having pericardial calcification and the amount of it doesn’t directly influence the patient’s condition. The outcomes can be worse for patients who experience long-term effects of restrictive heart function, including the wasting away of heart muscle, or for those also suffering from heart muscle disease. Particularly, the patients with advanced heart failure, classified as NYHA Class III and IV, have a worse prognosis given the higher risk of death from surgery.
How well a patient does long-term after the surgical removal of the pericardium for constrictive pericarditis, a condition where the sac-like covering around the heart hardens and constricts the heart, largely depends on what caused the condition in the first place. For instance, in a study of 163 patients, those with CP from unknown causes had a high survival rate (88%) 7 years post-surgery, followed by patients with post-surgical CP (66%), and post-radiation CP (27%). However, for patients being older, having been exposed to radiation before, suffering from high blood pressure in the lungs (pulmonary hypertension), kidney dysfunction, or liver failure, the outcomes tend to be less positive even after the surgery.
Possible Complications When Diagnosed with Pericardial Calcification
If there’s a buildup of calcium in the pericardium (the sac-like structure around the heart) and you’re experiencing symptoms, it’s important to have this checked out. This could indicate a condition called constrictive pericarditis, which can be cured if caught and treated properly. Without a surgery called pericardiectomy to remove the pericardium, constrictive pericarditis can lead to extremely poor health outcomes. This is mainly due to complications related to heart failure and a lower-than-normal output of blood from the heart. Other potential complications include kidney failure, the enlargement of organs, shock, and even death.
Potential Complications:
- Heart failure
- Low output state
- Kidney failure
- Organ enlargement
- Shock
- Potential death
Preventing Pericardial Calcification
It’s crucial to quickly identify and diagnose a condition called pericardial calcification and to rule out another condition known as constrictive pericarditis. This helps in timely management of these conditions and ensures the best health results. Pericardial calcification is often discovered by chance. With the use of a specific heart imaging technique called a cardiac CT scan, doctors are now able to detect pericardial calcifications in many patients who haven’t shown any symptoms. Just to define those terms, pericardial calcification is a condition where calcium builds up in the sac around your heart, and constrictive pericarditis is a severe inflammation and hardening of that same sac.
