Educational Series
This is the SMASH-HCM educational series, where we explain Hypertrophic Cardiomyopathy (HCM) and Digital Twin related topics.
What is Hypertrophic Cardio-myopathy?
Hypertrophic Cardiomyopathy (HCM)
It is the thickening of the muscle of the heart, usually the left ventricle (main pumping chamber of the heart). Due to
the thickened muscle the heart might scar and become stiff, reducing the blood flow in the heart. This can lead the heart
to beat irregularly (arrythmia) or to stop. The condition is often hereditary.
Obstructive vs. Non-obstructive
There are two common types of
hypertrophic cardiomyopathy. The obstructive type describes the thickening of the muscle in between the lower left and right ventricles which blocks the blood flow between both chambers. In the non-obstructive type the walls of the left ventricle are thickened and blood flow is reduced but not blocked.
What are Digital Twins?
Digital Twin
A Digital Twin is a virtual representation of a physical object, product, system or process that functions as a digital copy with which simulations, integrations, or maintenance can be performed to test and predict their influences on the physical version. This can help to improve a product or to predict what the end-of-life-stage of a product will look like.
Digital Twins vs. Simulations
Both Digital Twins and simulations use digital models to represent a process, product, etc., but a simulation tends to analyse only one aspect while a Digital Twin is able to run multiple simulations simultaneously. Additionally, Digital Twins can use real-time data to alter and adjust their models.
Digital Twins in Healthcare
Digital Twins can enhance patient care by creating personalised treatment plans, that can easily be adjusted with real-time data. They can also be used in training of health care professionals, as they allow them to practice procedures in a safe and realistic environment. Digital Twins can also be used to optimize clinical operations by analysing work flow and resource allocation.
SMASH-HCM and Digital Twins
SMASH-HCM is developing a Digital Twin platform to improve Hypertrophic Cardiomyopathy (HCM) stratification and disease management for patients and physicians. With personalised treatment plans, and tools for self-management and education, patients with HCM will be empowered to take an active role in their health journey.
Cardiac Digital Twins (CDT)
Benefits of Digital Twins in health care
Digital Twins can engance patient care, for instance by
- creating personalised treatment plans that can be adjusted using real time data
- being used to train health care professionals in a sage and accureate environment
- optimising workflow and resource allocation
- being used in disease prediction, prevention, diagnosis, and treatment
Cardiac Digital Twin (CDT)
A CDT is a digital representation of a heart. First a detailed 3D copy of the patient's heart, vasculature and upper thorax is made based on CT/MRI scans or echocardiograms. Digital Twins include functional aspects, allowing them to simulate and predict electric or mechanical functions of the heart. Physiological data like blood pressure, heart rate variability, and electrical activity are measured to create a dynamic and personalised model.
Depending on the 3D model, it can contain every chamber, valve and artery of the heart, and with the addition of mathematical models of blood flow, tissue mechanics and electrical conduction pathways to the 3D structure a functional model is created. The CDT needs continuous data input to update and adjust for any changes occurring with the patient. To ensure that the model is providing accurate information it needs to be compared to clinical data of the patient. A CDT can help with disease management and inform optimal treatment.
Downsides of Digital Twins in healthcare
While training the models data from a wide range of demographics should be considered to avoid any bias. Digital Twins require continuous input of data from a variety of data types, i.e. heart rate, blood pressure, blood oxygen levels, MRI/T scans, ECGs, blood glucose levels etc. In general, the more complex of a system that the Digital Twin is representing, the more data is required for the model's accuracy.
Ethical and Privacy concerns
Who owns the data? Data is collected through a variety of sources therefore transparency about ownership of the data is needed to allow patients to grant or revoke their consent on data use.
How secure is it? DTs deal with sensitive data and could be a target of cyberattacks. Reliable encryption and secure data transfers need to be guaranteed. How accurate are Digital Twins? Especiallymedical DTs like CDTs need to be accureat. If the model is inaccurate it can mislead healthcare professionals. If something goes wrong because of a flawed DT who is responsible for it?
How is Hypertrophic Cardiomyopathy diagnosed?
Hypertrophic Cardiomyopathy (HCM)
If HCM is suspected in a patient a series of tests can be done to diagnose it. If family history reveals that a relative has already been diagnosed with HCM, genetic testing can be done to determine if the patient is affected as well. On the next pages are some of the methods used to diagnose HCM.
Echocardiogram
An echocardiogram is an ultrasound based imaging test that uses soundwaves to create an image of the heart. It can show the heart chambers and valves while they are moving and tells the physician how the heart is pumping. It can also indicate if the muscles of the heart wall are thicker.
CMR Imaging
CMR imaging, or cardiac magnetic resonance imaging, is an imaging technology used to assess the function and structure of the heart. It is a non-invasive test and can show damaged tissue without needing to do a biopsy. In cardiomyopathies CMR can help determine potential risks of harmful cardiac events..
Electrocardiogram (ECG)
For an ECG electrodes are attached to the patient’s chest and sometimes arms or legs to measure the heart rate. This can help diagnose irregular heart beats (arrhythmia) or heart attacks. The test usually takes up to 10 minutes. It also exists as a holter monitor, a portable ECG device, that can be worn at home to measure the heart rate for 24-48 hours. This can show irregularities that are not visible during a normal ECG.
Exercise Sress Test
This test is done to measure the heart’s performance and reaction to physical activity. The test can be done on a treadmill or a stationary bicycle. During the test heart rate, blood pressure, and breathing are monitored, while the difficulty of the test is incrementally increased. A stress test can indicate how severely HCM is impacting the heart’s functionality.
How does HCM affect the Heart's functionality?
Some Facts about the heart
- It weighs between 200 and 425 grams.
- It is about the size of a fist.
- On average, a heart beats 100,000 times - every day.
- At rest, the heart pumps between 5 and 6 Liters of blood per minute.
The Heart's anatomy
The heart has 4 chambers: 2 at the top (left and right atria) and 2 at the bottom (left and right ventricle). Those 4 chambers are organised into two pumps (left and right) which provide blood flow. Inside the heart are 4 valves that allow the blood to flow forward and prevent it from flowing backwards:
- the tricuspid valve
- the pulmonary valve
- the mitral valve
- the aortic valve
How the Heart works 1
Deoxygenated blood that has been circulating in the body arrives in the right atrium through the superior and inferior vena cava. The blood then flows through the tricuspid valve into the right ventricle. From there the blood is pumped through the Pulmonary valve into the pulmonary artery and is distributed in the lungs.
How the Heart works 2
In the lungs the blood picks up oxygen before being collected in the left atria. The blood is then pumped through the mitral valve into the left ventricle, the main pumping chamber of the heart. The left ventricle pumps oxygenated blood through the aortic valve into the systemic circulation. And with every heart beat this cycle repeats.
HCM and the Heart 1
With Hypertrophic Cardiomyopathy, the muscle of the left ventricular wall is thickened. Over time the heart becomes stiffer, making it more difficult to pump blood efficiently and potentially leading to irregular heartbeats. A stiff heart muscle also makes it difficult for the heart to relax and allow blood to fill the chambers.
HCM and the Heart 2
In obstructive HCM the wall between both ventricles (interventricular septum) is thicker which can block blood flow. HCM can also affect the mitral valve, which can cause some blood to flow back into the left atria.
Hot Weather with Cardio-vascular Disease
The Body in Hot Weather
As the body is trying to regulate its own temperature in hot environments, more blood flows to the skin. This increases the heart rate and circulates about twice as much blood per minute compared to normally. Sweat production increases during heat, which can lead to fewer fluids in the body, lowering the blood volume. During hot or very humid weather the heart needs to work harder, which can f.i. worsen hypertrophic cardio-
myopathy (HCM) symptoms.
Risk Factors
- HCM and other cardiovascular diseases
- High blood pressure
- Lung diseases
- Certain medication like diuretics or for blood pressure
- Circulation problems
Signs of Heat Exhaustion
- dizziness, fainting
- excessive sweating
- cool, clammy and pale skin
- nausea or vomiting
- muscle cramps
➡️Cool yourself down!
Signs of Heat Stroke
- headache
- unable to sweat
- red, hot and dry skin
- body temperature above 39°C
- nausea or vomiting
- rapid and strong pulse
- may lose consciousness
➡️Call emergency services!
How to Cope in Hot Weather
- try to stay cool, keep your windows, shut and close curtains, blinds or shutters
- avoid being in the sun, especially between 11am and 3pm
- drink lots of cool water to stay hydrated
- take cold showers to help cool down
- reduce physical activity
- eat smaller and lighter meals
- wear loose clothing and stay protected from the sun
Familial Hypertrophic Cardiomyopathy
Hypertrophic Cardiomyopathy (HCM)
HCM is the most common genetic heart condition, affecting 1 in 500 people. The heart muscle becomes thicker and stiffer which can obstruct blood flow. When multiple members of a family have HCM it is also referred to as familial HCM. If a parent has been diagnosed with HCM their children have a 50% chance to also be affected by the disease
Familial HCM
If a family member has recently been diagnosed with HCM it is important that you mention it to your physician. Genetic testing can be done to determine if other family members are affected. Early detection and diagnosis are important to implement the necessary steps to maintain a healthy heart.
Hypertrophic Cardiomyopathy in Young Athletes
Hypertrophic Cardiomyopathy
HCM is the thickening of the muscle in the left ventricle (the main pumping chamber of the heart). In young athletes HCM is the leading cause for sudden cardiac death. Despite being a genetic condition, that begins to show up during the teen years, the disease often remains undiagnosed, and late treatment can lead to complications.
HCM in Athletes
Particularly in young athletes it often gets mistaken for left ventricular hypertrophy.
It is also a thickening of the muscle in the left ventricle, but athletes often develop it due to intensive training. Early
detection of HCM is therefore imperative, especially if a family member has already been diagnosed with it.
How is Hypertrophic Cardiomyopathy treated?
Treatments for HCM
There is no known cure for HCM, but treatments to manage symptoms are effective at improving quality of lifeThere are a variety of ways to treat HCM. Treatment is adjusted for each patient, as HCM can present differently in
individuals. Factors such as the severity of symptoms and if it is obstructive or non-obstructive HCM are considered for the treatment options.
How HCM can be Managed
- Lifestyle: staying active, eating healthy, maintaining normal weight monitoring blood pressure etc.
- Medication: to control blood pressure and heart rhythm like beta blockers, calcium channel blockers, diuretics
- Surgical and nonsurgical procedures: pacemakers, implantable defibrillators