What is Lutembacher Syndrome?
Lutembacher syndrome (LS) was initially identified in a letter by a body structure expert, Johann Friedrich Meckel, in 1750. It was later more thoroughly described in 1811 when Corvisart found a connection between an atrial septal defect (ASD – a hole in the heart’s wall that should normally be closed) and mitral stenosis (MS – a narrowing of the heart’s mitral valve). However, the syndrome was named after a French doctor named Rene Lutembacher, who provided the first detailed explanation of these two heart issues in 1916.
Interestingly, Lutembacher first spotted this syndrome in a 61-year-old woman, attributing the heart valve problem to a birth defect causing mitral stenosis. The exact meaning of Lutembacher syndrome has seen many changes over time and there’s no general agreement on which heart defects should be included under this name. While some say it refers to cases of mitral stenosis and atrial septal defect, others suggest that the syndrome could also include cases of mitral regurgitation (a condition where the heart’s mitral valve doesn’t close tightly causing blood to flow backward) with an atrial septal defect.
However, the current understanding of Lutembacher syndrome includes any combination of atrial septal defect and mitral stenosis, whether they’re present from birth or develop later in life due to other medical procedures. In cases that follow this definition, the size of the hole in the heart is commonly larger than 15 mm. Lately, a condition known as iatrogenic LS (a variation of the syndrome caused by medical procedures) has become more frequent because of a procedure to widen the mitral valve known as percutaneous balloon mitral valvuloplasty.
What Causes Lutembacher Syndrome?
Lutembacher’s syndrome (LS) can either be present at birth, also known as congenital, or it can develop later in life, which is referred to as acquired. LS happens when there’s an opening in the wall of the heart (atrial septal defect or ASD), and there’s a narrowing of the heart’s mitral valve (mitral stenosis or MS). The frequency of patients born with ASD who also develop MS is about 0.6% to 0.7%.
As we’re seeing more patients with MS treated through a less invasive heart valve procedure, called trans-catheter balloon mitral valvuloplasty (BMV), there has been an increase in cases of ASD left after the procedure. This has led to more cases of LS caused by medical treatment, which we call iatrogenic.
It’s very rare for a person to be born with MS – it only makes up 0.6% of heart problems that people are born with. The MS seen in LS is always caused by what we call rheumatic heart disease (RHD). With the rate of ASD being pretty much the same worldwide, the number of people with RHD and MS together varies depending where you are in the world, due to different rates of RHD from place to place.
Risk Factors and Frequency for Lutembacher Syndrome
It’s not exactly clear how common Lutembacher’s syndrome (LS) is. However, we do know that it’s likely to be more common in places where there’s a high occurrence of rheumatic heart disease (RHD). This is why we hear about it more in Southeast Asia. In developing countries, about 40% of people with LS have had rheumatic fever in the past. LS can appear at any age but it’s usually more common in young adults. The syndrome is seen more in females because it’s associated with two conditions – atrial septal defect (ASD) and rheumatic mitral stenosis (MS) – that are both more common in females.
Signs and Symptoms of Lutembacher Syndrome
LS, a medical condition, is usually well-tolerated by patients because the blood bypasses certain heart structures, going directly to the right chamber of the heart. Common symptoms associated with lung-related high blood pressure, such as coughing up blood, shortness of breath during the night, and difficulty breathing while laying flat, occur less frequently in people with this condition, thanks to the release of pressure in the upper left chamber of the heart. However, these symptoms are more common among patients with a small ASD (a hole in the heart). Other symptoms like heart palpitations and fatigue show up early in patients with LS. This is due to the increased blood flow from the left to the right chambers and a subsequent reduction in blood output throughout the body.
If a patient has both an ASD and MS (mitral valve stenosis), a heart valve disease, the physical symptoms from each ailment can interact and change. Because the upper chambers of the heart function as a common compartment in a non-restrictive ASD, the jugular venous pressure, a measure of the indirect heart pressure, is increased even without congestive heart failure. Certain features of the pulse, such as low volume, might be present due to reduced stroke output from the left ventricle. The physical heart examination may show peculiarities like a visible pounding of the heart on the left side and a vibration that can be felt during the heartbeat. These specific signs are more evident in patients with an LS and a large ASD, in comparison to a simple ASD, because the MS increases the level of blood bypassing the heart.
The typical heart signs of MS, such as a loud first heart sound, an extra sound following the first one, and a specific type of heart murmur heard during a heartbeat, might be challenging to discern in patients with LS and might go unnoticed. As the right ventricle of the heart is enlarged and dominates the heart’s tip, the examination findings relating to blood flow into the left ventricle might be less noticeable. Conversely, the examination findings of a large ASD, like a distinctive second heart sound and a specific heart murmur over the upper left side of the heart, are easier to identify. Another type of heart murmur, resulting from the overflow of the heart’s right chamber, might be heard on the left side of the chest and appear more prominent toward the heart’s tip. The increased intensity of this murmur while inhaling (Carvallo’s sign) differentiates this sound from the murmur of MR (mitral regurgitation).
Testing for Lutembacher Syndrome
The electrocardiogram (ECG), a test which checks the electrical activity of your heart, may show tall and sharp P waves in certain leads or channels tracking the heart’s electrical signals. There might also be a deep, extended negative deflection of the P wave in lead V1. These are all indicators of an increase in size of both parts (left and right atrium) of your heart’s upper chambers. Additionally, the QRS, another type of waveform on the ECG depicting how the heart’s lower chambers are functioning, might show a shift to the right, indicating an abnormal enlargement of the right lower chamber of your heart (right ventricular hypertrophy), along with complete or incomplete right bundle branch block (a delay or blockage in the electrical signals traveling through certain pathways in your heart). Enlargement of the right ventricular and irregular heart rhythm both occur more commonly in Lutembacher’s syndrome (LS) as compared to when there is a hole between the heart chambers (isolated atrial septal defect).
Chest x-rays can give more information about the condition of your heart. It may show signs of enlargement of the right atrium (upper chamber of the heart), the right ventricle (lower chamber of the heart), and the main pulmonary artery (the vessel carrying blood from the heart to the lungs). You might also have increased end-on pulmonary vascular markings indicating more blood flow from left to right due to the hole in the heart. However, collection of fluid in the lungs is usually absent unless the hole in the heart is too small.
A type of ultrasound known as two-dimensional echocardiography combined with color flow Doppler can confirm the diagnosis of LS. This can accurately estimate how narrow the valve between the left atrium and left ventricle has become (mitral stenosis) and the size and type of hole in your heart. The pressure gradient or difference across the mitral valve is often less despite the valve being severely narrow.
Doppler pressure half-time, a measurement used to assess the valve’s size, may overestimate the valve’s opening because the hole in the heart reduces the pressure in left atrium and therefore reduces the pressure difference across the mitral valve. Planimetry, a way of visually calculating the valve’s size, is generally more reliable in assessing the severity of mitral stenosis in patients with LS.
Transesophageal echocardiography, a type of ultrasound where the probe is inserted through mouth into esophagus, can outline the site and size of the hole in the heart and its flow pattern. These days, direct measurement of arteries and heart’s chamber through cardiac catheterization is rarely needed to diagnose LS. Once in a while, doctors would still need to measure the mitral valve area, check whether high blood pressure in the lungs (Pulmonary Arterial Hypertension or PAH) can be reversed, and examine the coronary arteries in high-risk patients.
Treatment Options for Lutembacher Syndrome
To manage the symptoms of conditions like right-side heart failure or congestion in the lungs, doctors often prescribe diuretics. These are medicines that help your body get rid of extra water and salt through urine. You might also receive beta-blockers or calcium channel blockers to control a fast or irregular heartbeat in a condition known as atrial fibrillation. Moreover, your doctor may recommend steps to prevent infective endocarditis, an infection of the inner layer of your heart, usually of the heart valves.
Traditionally, open heart surgery used to be the foremost treatment. But with advances in less invasive procedures and technologies, there has been a shift towards percutaneous transcatheter therapy. This is a non-surgical procedure that uses a thin, flexible tube (catheter) to repair the heart. It has become the preferred treatment option for certain heart conditions. For example, balloon mitral valvuloplasty (BMV) is a procedure used to widen a narrow heart valve (a condition known as mitral stenosis, or MS). There’s also a procedure for closing a hole in the heart, known as an atrial septal defect (ASD).
However, surgery may still be needed for some cases, particularly when the defect is too large to be managed with a percutaneous device closure or when the narrowing of the heart valve is not suitable for a balloon procedure.
Preventing Lutembacher Syndrome
Patients should be instructed to be observant for signs indicating their body might be retaining too much fluid. This condition is known as ‘fluid overload’ and should not be overlooked.
