Dr. Vliet’s Health Tip: Myocarditis ~ Silent Killer & A Revolutionary Strategy

© by Elizabeth Lee Vliet MD and Kathy Kresnik

Myocarditis is diffuse, destructive, and progressive inflammation of the heart muscle (the myocardium) that can weaken the heart’s pumping function and disrupt its electrical system. This ultimately leads to heart failure, arrhythmias, and even sudden death if not diagnosed and treated early.

Prior to 2020 and the rollout of COVID-19 vaccines, myocarditis was less common and exhibited a bimodal age distribution in many epidemiological studies and global reports. “Bi-modal” means diagnoses peaked in two main groups: young children under 5 years + adolescent and young adult males (teens to early 30s), with a second rise in older adults over 65 (peaks from 65-69 or later).

After 2021, following widespread rollout of COVID-19 vaccines (primarily mRNA vaccines like Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273), the demographic pattern of reported myocarditis shifted markedly. Vaccine-associated myocarditis (often called C-VAM) showed a strong predominance in adolescent and young adult males with 87-92% of reported cases in males aged 12–39 years, with the highest incidence in males aged 12–17 and 18–24. Most cases occurred within 2–7 days (median 2–3 days) after vaccination, predominantly after the second dose of mRNA vaccines. Rates were lower after dose 1, boosters, or non-mRNA vaccines.  So we see that the mRNA COVID shots in particular have caused devastating cardiovascular effects for healthy young people, including elite athletes.

My concern has been that myocarditis is a “silent threat” without a lot of symptoms until it is has already caused severe damage to heart muscle.  Myocarditis can occur with what appears to be a relatively mild viral illness and then suddenly progress to life‑threatening complications, including sudden cardiac arrest, especially in young and otherwise healthy people.

My second big concern is that myocarditis doesn’t just harm the heart muscle—it damages the critical lining of blood vessels, the endothelium, and the glycocalyx (the inner most layer of the endothelium), both inside and outside the heart.  This “silent” damage gradually triggers a cascade more damage leading to poor blood flow, increased risk of micro-and then macro- blood clots, heart dysfunction, and then ultimately heart failure.

Most people are unaware of the massive increase in exposure to higher risk of myocarditis and endothelial-glycocalyx damage.  Approximately 70% of the US population has received at least one SARS-CoV2 mRNA shot and up to 95% have been infected with the virus. We know that recent viral infection, including respiratory viruses and SARS‑CoV‑2, increases myocarditis incidence roughly 15‑fold compared with pre‑COVID baselines (from about 1–10 per 100,000 to ~150 per 100,000 among infected patients).

Many studies now show that mRNA Covid‑19 vaccines are also associated with an excess risk of myocarditis, mainly in adolescent and young adult males, usually within a few days after the second dose. The reported rates in young males range from roughly 12.6 per million second doses in CDC data up to around 70 per million in the highest‑risk group -adolescent males. The military estimates a rate of 10–20 per 100,000 in young men after a second dose.  Some post‑vaccine myocarditis cases were mild and responded to conservative treatment with good short‑term outcomes, but long‑term follow‑up is necessary to be sure that there are not the silent, more severe complications developing.

Maybe you have heard a lot about myocarditis, but doctors are often downplaying the risk from the COVID shots, and often failing to warn people that the damage stretches beyond the heart muscle to include the entire system of blood vessels in our body.  I know from my own patients experience with other doctors that most physicians are NOT monitoring patients for the early signs of “silent” damage, and are not then helping people with solutions to reduce the risk of long-term complications, such as heart failure, before the people become severe.

We are faced with biological and clinical risk factors that 70-95% of the population have been exposed to and a silent threat with long-term damage you may not be aware of—unless you know what to look for.  That’s why I wanted to do this Health Tip, to discuss the early signs of myocarditis and damage to the blood vessel lining, so you can begin to take steps to reduce the damage, and help heal damaged tissue.  Later in this Health Tip, I will describe more on the damage to the endothelium and glycocalyx, and some options to help reduce damage with nutraceuticals.

Inflammation of the Myocardium, Endothelium and Glycocalyx

When a condition ends with “itis “ you know you are dealing with inflammation, swelling, or edema (retention of fluids). Myocarditis is inflammation of the middle muscular layer of the heart wall called the myocardium which is responsible for contraction and pumping blood. Inflammation weakens heart muscle fibers and interferes with the heart’s electrical conduction, reduces the heart’s ability to pump efficiently and often leads to arrhythmias (irregular heartbeats), clot formation, heart failure, and the shocking sudden cardiac deaths.

Myocarditis has been classified as a rare disease, but it still affects many thousands of adults and children yearly worldwide.  The bigger problem now is that media still reports it as “rare” but current CDC and other official reports do not take into account the dramatically increased risk following the rollout of the COVID-19 shots. The other dangerous aspect of myocarditis is that it can be “silent” and not cause symptoms severe enough to see a doctor, yet the damage is taking place.

This diagram sums it up well:

Summary of Causes of Myocarditis
The common thread for all these causes of myocarditis is INFLAMMATION of the heart muscle, cells, vascular endothelium and glycocalyx.

• Viral infections (e.g., adenovirus, SARS‑CoV‑2, hepatitis B/C, parvovirus, herpes simplex) increase myocarditis risk through a combination of direct viral injury to heart cells and an intensified immune response that ends up attacking the heart muscle itself.
• Bacterial infections (e.g., Staphylococcus, Streptococcus, Lyme disease, Mycoplasma and others) increase risk when bacteria or their toxins reach the heart and triggers intense inflammation that damages the heart muscle and endothelium.
• Fungal and Parasitic infections (e.g., Candida, Aspergillus, and Histoplasma; Trypanosoma cruzi and Toxoplasma gondii) can cause myocarditis especially in people with weak immune systems.  When these organisms invade heart tissue or its vessels, the immune response plus direct pathogen toxicity together inflame and damage the myocardium.
• Autoimmune diseases (e.g., lupus, rheumatoid arthritis, and others) increase risk because they generate immune responses that either directly target cardiac proteins or chronically prime the immune system so that the heart muscle becomes collateral damage during systemic inflammation.
• Hormone Disorders/Imbalances: there are several endocrine (hormonal) causes of damage to heart muscle and the microvasculature that are often overlooked: hyperthyroidism (either from excess thyroid medication or untreated Graves autoimmune thyroiditis), hypothyroidism (either from Hashimoto’s autoimmune thyroiditis or inadequately hypothyroidism), menopausal loss of estradiol, testosterone excess in women, and testosterone deficiency in men; hyperparathyroidism and hypoparathyroidism causing serous calcium imbalances that disrupt heart and blood vessel function.
• Drugs and toxins (certain chemotherapy agents, antibiotics, other cardiotoxic agents, some environmental toxins) increase risk mainly via two pathways: direct toxic injury to cardiomyocytes and through an immune-mediated attack on the heart muscle. This is one reason cancer patients often see a cardiologist throughout their treatments to monitor for heart damage.
• Other medications: Certain antipsychotics (e.g., clozapine), some antibiotics (e.g., penicillin, sulfonamides), some antiseizure drugs, and other cardiovascular or psychiatric medications increase risk. If you are taking any these medications and begin to have symptoms I describe below, you need to ask your doctor to check heart function.
• Illicit drugs: Cocaine and other stimulants can cause myocarditis via direct toxicity, vasospasm, and intense sympathetic activation.
• Environmental and occupational toxins: Exposure to carbon monoxide, heavy metals (e.g., copper, lead), insecticides, pesticides, and other industrial chemicals is associated with myocarditis or broader toxic cardiomyopathy.
• Radiation: Therapeutic chest radiation can trigger inflammatory damage that injures the heart muscle, blood vessels and surrounding structures over time, contributing to myocarditis and later cardiomyopathy.
• Physical injuries: Severe electric shock, profound hyperthermia, and direct physical trauma (a good example is impact during football) to the heart are less common but recognized triggers.
• Idiopathic cases: Even with thorough evaluation, 50–80% of myocarditis cases never yield a clear cause, and are classified as idiopathic, though many are presumed to be immune‑mediated or due to unrecognized infectious or toxic triggers.

People at higher risk for myocarditis include those exposed to the above risk factors including viral infection, those with autoimmune disease or have immunodeficiency which increases infection susceptibility. Prior myocarditis or cardiomyopathy puts a person at greater risk due to an underlying vulnerability. Myocarditis is often more common in children and young adults, including otherwise healthy individuals.

As we have seen in the headlines, Myocarditis has been implicated in up to around 10–14% of sudden deaths in young athletes. Males have higher frequency, especially viral myocarditis. Athletes doing high intensity or endurance exercise during or shortly after a viral illness are more at risk because vigorous exercise can exacerbate viral myocardial inflammation and increase the risk of malignant arrhythmias and sudden cardiac death.

Signs and symptoms

Many people have no or only mild symptoms, which is a major reason I said myocarditis can be a silent killer.  When present, symptoms can range from nonspecific viral‑like complaints to clear cardiac features.  In addition, many myocarditis symptoms overlap with and can mimic other conditions.  So when you begin to experience symptoms on this list, you need to be proactive and seek a comprehensive medical evaluation.

• Fatigue or exercise intolerance.
• Flu‑like illness: fever, headache, body aches, joint pain, sore throat.
• Chest pain, often sharp or stabbing; sometimes mimics myocardial infarction.
• Shortness of breath at rest or with exertion; orthopnea (shortness of breath when lying down that is relieved by sitting or standing) in more advanced cases.
• Palpitations, rapid or irregular heartbeat.
• Lightheadedness, presyncope, or syncope (fainting), especially with exertion.
• Peripheral edema: swelling in legs, ankles, or feet.
• Rapid weight gain from fluid retention.
• Marked dyspnea (uncomfortable breathing or shortness of breath), reduced exercise capacity, signs of low cardiac output (e.g., cold extremities, hypotension in severe cases).

Risk of sudden, severe events! Even when symptoms are mild, inflammatory injury and electrical instability can precipitate malignant ventricular arrhythmias and sudden cardiac death.

• Undiagnosed myocarditis can silently progress to dilated cardiomyopathy, chronic heart failure, or permanent structural damage, and unfortunately sometimes only recognized after a major event like heart failure decompensation, stroke, or cardiac arrest.
• The key is early recognition. The gold‑standard diagnosis is endomyocardial biopsy is invasive and adds risk, so it is not routinely used.  Doctors often rely on a combination of clinical features: ECG, biomarkers, echocardiography, and cardiac MRI done according to special protocols to pick up myocarditis inflammatory changes.
• The risk is that milder cases may go unrecognized. Epidemiologic data and autopsy studies suggest that the prevalence of “silent” myocarditis, especially in pediatric and adolescent populations, is higher than appreciated and may contribute to these unexplained sudden deaths.

CAUTION!

• Any new, unexplained chest pain, shortness of breath, palpitations, or syncope—especially in the weeks to months after a VACCINE, a viral infection or while on cardiotoxic medications—needs rapid medical assessment, including lab and imaging studies to check for myocarditis.
• For athletes and highly active individuals, guidelines emphasize rest and refraining from intense exercise during and for a period after viral illness, and careful evaluation before return to play if cardiac symptoms are present, to reduce the risk of exercise‑triggered arrhythmic events.

REMEMBER! Signs and symptoms of myocarditis can appear days to months after infectious illness and/or COVID and other vaccinations, and can evolve over time.

Damage That Stretches Beyond the Heart Muscle to Blood Vessel Linings

Lining the inside of your capillaries is the endothelial glycocalyx
This vast protective micro-thin gel lining that touches each of your trillions of cells. The integrity of the glycocalyx structure and function is important because the continuous delivery of nutrients, hormones, and oxygen, and the elimination of waste and carbon dioxide, flows through the capillaries.Myocarditis damage goes much further than just the heart muscle.  It causes significant injury to the inner lining of blood vessels, known as the endothelium. This lining is essential for regulating blood flow, controlling inflammation, and preventing blood clots. When myocarditis hits, it causes damage to the tiny blood vessels within the heart and throughout the body.

Myocarditis injures the endothelium through a combination of direct vascular infection/insult and “collateral” damage from the myocardial inflammatory response, producing coronary microvascular dysfunction locally as well as endothelial  injury throughout the body.

Endothelial cells become targets of infection which leads to cell stress, apoptosis (cell death), tight-junction disruption and barrier leaks, all early steps in endothelial dysfunction. Inflammatory and immune-mediated endothelial damage release cytokines which directly reduce nitric oxide availability and increase oxidative stress.

The small blood vessels in the heart (coronary microvasculature) suffer both structural and functional damage. This leads to poor blood vessel relaxation (vasodilation), higher resistance to blood flow, uneven blood supply, and low oxygen levels in the heart tissue. These changes are called coronary microvascular dysfunction.

Normally, a substance called acetylcholine helps these vessels relax, but in myocarditis, it can cause them to tighten instead, a clear sign of endothelial dysfunction. Injured blood vessels can leak fluid and become swollen, and tiny blood clots can form, reducing the number of functioning capillaries. This makes it even harder for oxygen to reach heart cells, worsening damage and feeding a cycle of inflammation and further injury.

Then there is a “communication breakdown” between the blood vessels and heart cells. Healthy blood vessels send signals that help the heart work properly.  When blood vessels are inflamed, these signals promote vessel tightening, heart cell enlargement, and scarring. This abnormal signaling leads to stiffing of heart cells and the buildup of fibrous tissue, causing the heart’s chambers to change shape and function poorly in pumping blood.

Over time, this stiffening of heart muscle fibers results in heart failure, especially a type called heart failure with preserved ejection fraction (HFpEF), where the heart can pump but doesn’t relax well.

Myocarditis also affects the whole body. It often triggers widespread inflammation, with high levels of signaling proteins (cytokines) in the blood. These can activate and damage blood vessel linings throughout the body, not just in the heart.

Damaged blood vessels produce less nitric oxide, a substance that keeps vessels relaxed. Nitric oxide also prevents abnormal blood clotting. The lining of blood vessels become “stickier,” which means more white blood cells and platelets can attach, increasing the risk of vessel tightening and more blood clots. Injured endothelial cells can break off and circulate in the blood, releasing particles that further fuel inflammation, clotting, and vessel damage.

This all leads to symptoms and long-term injury. Damage to the coronary blood vessels causes chest pain, reduced blood flow (ischemia).  People don’t realize that these changes can even cause heart attacks without major artery blockages.

This system-wide blood vessel damage also raises blood pressure in the body and lungs, making physical activity harder and increasing the risk for abnormal heart rhythms and blood clots. This is especially the case after myocarditis has occurred and the heart is remodeling.

BOTTOM LINE:
Myocarditis doesn’t just harm the heart muscle—it damages the critical lining of blood vessels, the endothelium and the glycocalyx —both inside and outside the heart – which triggers a cascade of damage: poor blood flow, heart dysfunction, increased risk of blood clots, and ultimately heart failure.

An Innovative Solution to Protect Your Heart and Blood Vessels

Experimental work in viral myocarditis models shows that preserving or restoring the endothelial glycocalyx  can reduce cardiac inflammation and death.  This new research really caught my attention and reaffirmed my confidence in one of our most popular products: Endocalyx Pro™, a supplement designed to help repair damage to the blood vessels, especially the glycocalyx, and help protect blood vessels and heart from further harm.
Endocalyx Pro™ contains a blend of ingredients that each target a key part of the injury caused by myocarditis:

• Restoring the Glycocalyx and Endothelial Lining: Ingredients like fucoidan (from seaweed), high-molecular-weight hyaluronic acid (HA), and glucosamine provide building blocks to rebuild and strengthen the protective layer on blood vessels, making them less “leaky” and more resilient. This helps limit swelling and improves blood flow.
• Fighting Inflammation and Oxidative Stress: Plant extracts from olive, artichoke, and grapes (rich in polyphenols), along with antioxidant enzymes from bitter melon, help calm inflammation, reduce damaging molecules (called reactive oxygen species or ROS), and protect the blood vessels from further injury. This is especially important because inflammation and oxidative stress drive much of the ongoing damage after myocarditis.
• Supporting Healthy Blood Flow and Vessel Function: By repairing the glycocalyx and boosting nitric oxide (a molecule that helps blood vessels relax), Endocalyx Pro™ supports better blood flow, reduces the risk of clots, and helps the heart get enough oxygen. This also lowers the chance of ongoing chest pain, abnormal heart rhythms, and long-term heart dysfunction.

EndocalyxPro™ is a proprietary, patented dietary supplement that has been clinically shown to maintain a healthy glycocalyx. EndocalyxPro™ provides the building blocks needed for a strong and vital glycocalyx, strengthening this micro-thin shield that protects the heart, arteries, microcirculation and veins. It helps keep blood vessels slick, smooth and protected inside, from the largest arteries and veins to the tiniest capillaries. This keeps blood flowing freely while optimizing circulation throughout the entire body. It strengthens the glycocalyx and helps optimize the structure of the capillaries, which allows them to exchange oxygen and carbon dioxide, nutrients, and waste more efficiently.

BENEFICIAL ATTRIBUTES OF ENDOCALYX PRO™

• Regenerates the Microcirculation System*
• Provides the anti-aging building blocks needed for a strong and vital glycocalyx, strengthening this micro-thin shield that protects the heart, arteries, microcirculation and veins.*
• Helps keep blood vessels slick, smooth and protected, from the largest arteries and veins to the tiniest capillaries. Slick vessels make it harder for plaque to form keeping blood flowing freely while optimizing circulation throughout the entire body.*
• Allows more efficient delivery of oxygen and nutrients to tissues, organs and for the removal of waste.*
• Endocalyx Pro™ also helps reverse hypoxia (impaired oxygenation at the cellular level), which helps prevent organ suffocation from lack of optimal oxygen.*

*Company product data from scientific studies, not evaluated by the FDA

Endocalyx Pro™ hasn’t been specifically tested in people with myocarditis, but the science behind its ingredients suggests that it supports the body’s natural repair processes and may help protect against future blood vessel and heart damage.

If you have myocarditis, Endocalyx Pro™ is best used along with your doctor’s recommended treatments—not as a replacement—for overall heart and vascular health.

Other conditions and diseases showing benefit with Endocalyx Pro™ include (since these are made worse by microvascular damage):

• Hypertension
• Erectile Dysfunction
• Diabetes
• Heart disease
• Inflammatory Disorders
• Cancer Metastasis
• Stroke
• Kidney Disease
• Septic Shock
• Mild Cognitive Decline and Dementia

For those not familiar with EndocalyxPro™ please refer to my original Health Tip – Repair Blood Vessel Damage with a Powerful Natural Alternative: Endocalyx Pro and our Faith Over Fear program on April 15, 2025: EndocalyxPro: The Science Behind A Life Changing Nutraceutical

CAUTION: As always, we urge you to avoid supplements without checking knowledgeable sources to evaluate your medical situation, proper lab tests to verify what is needed, and to make sure to avoid adverse interactions with prescription medicines and other supplements you take.

All Truth for Health Foundation Products Meet or Exceed cGMP Quality Standards, the highest quality standard for supplements sold in the USA.

For more information, references from studies are listed in the Product Data Sheets for each product, available on our website.  Under medical practice regulations, we are unable to answer individual medical questions or make specific individual supplement recommendations for people who are not established patients of Dr. Vliet’s independent medical practice.

I encourage you to consider our other natural medicines with our top quality, cGMP-compliant professional formulas: TruMitochondrial™ Boost,  TruNAC™, Tru BioD3, Tru B™ Complex Full Spectrum, TruZinc™, TruC with BioFlavonoids (Vitamin C with complete Bioflavonoids), and TruProBiotic™ Daily to replenish critical bifidobacteria depleted by COVID shots, viral illnesses, and antibiotic therapy.

To Your good health and improving resilience!
Elizabeth Lee Vliet, MD