Matthew's Cause of Death
When Matthew died on December 9, 2008, he had been sick for a day with a cold in his throat, sometimes called croup. It didn’t make sense that at 9 ½ year old healthy boy would die from a disease that rarely kills infants; a nine year-old’s airway is far larger than an infant or toddlers and can tolerate inflammation unlike a younger child’s. After two months and some special tests, it was determined that Matthew died of lymphocytic myocarditis. Below is our attempt to document our latest and best understanding of the cause of Matthew’s sudden death. Also included is a chronology of his last 36 hours.
Summary
Basically, a virus attacked Matthew’s heart and caused it to fail. The autopsy (which took 7 weeks to complete) determined that his heart had a rare condition called Lymphocytic Myocarditis (swelling/inflammation of the myocardium of the heart) which can cause fatal arrhythmias and/or sudden heart failure.
A fatal arrhythmia (which is when the heart beats improperly) caused by the damage to his heart is what killed him. The type of arrhythmia is unknown but the arrhythmia lead to Sudden Death (sometimes referred to as Sudden Cardiac Death or SCD).
Lymphocytic Myocarditis: Myocarditis is inflammation of the myocardium with a wide range of clinical presentation, from subtle to devastating. It usually manifests in an otherwise healthy person and can result in rapidly progressive (and often fatal) heart failure and arrhythmia.
Lymphocytic myocarditis usually manifests in an otherwise healthy person and can result in rapidly progressive (and often fatal) heart failure and arrhythmia. Sudden death, even in the presence of doctors, can occur. It can develop rapidly with no apparent heart-specific symptoms. Cold or flu-like symptoms (fever, vomiting, upper respiratory infections) are often present either concurrently or days or weeks prior the sudden death event.
Myocarditis can then cause heart failure as well as heart rhythm irregularities from inflammation and/or scarring of the electrical system of the heart.
What is the myocardium?: The myocardium is the heart's muscular wall. It contracts to pump blood out of the heart, then relaxes as the heart refills with returning blood.
What is inflammation?: Inflammation is the response of body tissues to injury or irritation and is characterized swelling
What causes lymphocytic myocarditis?: Viruses, bacteria, and toxins can cause lymphocytic myocarditis. It is believed that a virus caused Matthew’s. Viruses known to cause Lymphocytic myocarditis include: CMV, parvovirus and coxsackie. The viruses attack the heart and the heart’s immune response creates the Lymphocytic Myocarditis condition.
Do we know what virus caused the lymphocytic myocarditis?: It is still unclear which virus attacked Matthew’s heart. It could have been the cold virus (called parainfluenza Type B which is NOT the influenza virus that causes the flu but instead is a virus that causes croup and respiratory tract infections) that was present in his throat and bronchia (which caused his heavy breathing or croup-like symptoms), but this virus is not typically associated with Lymphocytic Myocarditis. Additional testing of his heart tissue by the CDC is ongoing in an effort to identify the virus. However, it is possible that the virus may never be identified.
How is it diagnosed?: Because the disease is so variable, it is difficult to diagnose and detect. If the myocarditis is caused by a virus (the most common cause in the industrialized world), the symptoms of the myocarditis may be masked by the viral infection. In some cases, patients may not be aware they are suffering from myocarditis at all.
It is diagnosed by established histologic, immunologic, and immunochemical criteria.
How does lymphocytic myocarditis lead to death?: Myocarditis is described as "an inflammatory infiltrate of the myocardium with necrosis and/or degeneration of adjacent myocytes."
Experimental and clinical evidence suggests that the myocardial damage results from an immune-mediated mechanism rather than from a direct effect of the virus.
This means that as the cardiac tissue fights the virus, it damages itself. This damage to the heart tissue can lead to a disturbance in the heart’s ability to conduct the electrical signals that make the heart beat. This disturbance is called a heart arrhythmia and it can lead to sudden death. This is the effect it had in Matthew.
The damage to the heart can also lead to congestive heart failure (CHF) which is a condition in which the heart can't pump enough blood to the body's other organs. As the tissue in the heart dies, the heart muscle is damaged and has to work harder to pump which leads to enlargement of the heart and deterioration in heart function. This can lead to death or the need for a heart transplant.
It wasn’t croup?: In the first few weeks after Matthew’s death, it was thought that the constriction of his airway due to laryngospasms (spasms of the vocal chords) or swelling of his throat could have led to asphyxiation. For a variety of reasons and the results from the autopsy, this is now deemed unlikely.
How is Lymphocytic Myocarditis diagnosed?: Lymphocytic myocarditis is hard to detect and thus prevent. In most cases, a heart tissue biopsy is required which is usually not a practical option until other possible causes for illness have been dismissed.
How is Lymphocytic Myocarditis treated?: Lymphocytic myocarditis can resolve itself without any damage or knowledge that the heart was impacted. Sometimes it can be chronic (last for weeks) and result in heart enlargement and/or congestive heart failure. Typical treatment is to monitor and support the patient. Treatment with a temporary pacemaker and/or anti-inflammatory drugs has had some success. Sometimes heart damage is severe and transplants are required.
Lymphocytic Myocarditis appears to occur more frequently in children and young adults more than adults. There are several references of SIDS cases in which lymphocytic myocarditis is proposed as the cause of death.
Based on our literature searches, it appears that the exact cause of many sudden deaths remain unclear. This is particularly true for SIDS (sudden infant death syndrome) cases. It also appears that lymphocytic myocarditis can often be overlooked by the Medical Examiner community as a potential cause of death in Sudden Death cases—the proper analysis is simply not done. In fact, this was almost true in our case as we actually had to ask the Medical Examiner to conduct the additional testing to look for possible arrhythmias which we thought could have been genetic. Instead, the additional pathology found that the heart was damaged by lymphocytic myocarditis and that led to the arrhythmia and sudden death.
Chronology of Matthew’s last 36 hours
Sunday, Dec 7th. Sunday was a relatively typical day. Everyone seemed healthy and rested after a night of cookie decorating with our neighbors. That day we had gone to church and Matthew and Nathan had gone sledding with some other neighbors. We had bought our Christmas tree the day before and were getting ready to decorate the tree around 7 PM when Matthew mentioned that he had a sore throat. Mike also noted that his throat was also sore. So, we trekked to Urgent Care for strep testing for Matthew, Nathan and Mike. Matthew had a low grade fever (under 100 F) and the quick test was negative for all three. Eventually, the 24 hour results showed that only Mike was strep positive.
We went home and went to bed at our usual time. Matthew did not exhibit any other symptoms and was in a good mood when he went to bed. We remember him assuring his Dad that his large tower of books over his bed were not at risk for falling on his head. “Don’t worry, Dad. It will be OK”, he said. The tree remained undecorated.
Monday, Dec 8th. The alarm went off at 7:05 AM as usual. Matthew woke up, got dressed and went to the kitchen for breakfast. Mike fed him and noticed that he didn’t look so well. When Jennifer came down with Nathan, she agreed and decided to keep Matthew home. Nathan then convinced Jennifer that he didn’t feel well either so he stayed home as well. Jennifer made breakfast and Matthew ate again.
After some movie watching and playing, Nathan was clearly fine. Matthew, however, had developed heavy, raspy breathing. He did not have a cough though nor did he have a fever. Jennifer took him to the doctor around 11 am. The doctor listened to his heart; it sounded fine. His throat and ears looked fine, too. They took a blood sample; white cell count was normal (which indicates that there was no white blood cell response which is typically seen if there is an infection). They took a chest x-ray; his lungs looked clear. He threw up on the X-ray machine; they cleaned it up. They put a blood gas sensor on his finger; his oxygen levels were normal. They were sent home with directions to get rest and monitor Matthew’s symptoms. To ease his breathing symptoms it was recommended to expose Matthew to cold (ie, on the porch) or high humidity (ie, steamy bathroom); this was done and seemed to help a little.
Matthew rested and Nathan and Jennifer decorated the Christmas tree. Matthew was sleeping on the couch when Dad returned home from work around 6:30 PM. His breathing sounded typical at that point, but heavy breathing returned later. He awoke and eventually watched part of a movie that evening. He did not eat and was clearly lethargic. His heavy, raspy breathing continued but did not seem to be worse than it was in the afternoon. He looked and sounded sick. He went to bed around 9:30 with a possibly a slight fever. He did throw up a few times as we tucked him in bed; his stomach was pretty much empty…
Nathan and Matthew share a room so we had Jennifer sleep in Nathan’s bed in order to keep close watch on Matthew. Nathan slept with Dad.
Tuesday, Dec 9th Mike heard Matthew get up around 3:30 AM. Matthew was heading downstairs to go outside and sit on the porch in order to see if it would help him breathe easier. Dad joined him. They sat in their coats for about 15 minutes. It was snowing. His breathing was still raspy and required some extra effort but it was calm and steady. His mouth would open wider as he’d breathe in. When his Dad asked him to breathe through his nose, he did so. When asked why he was breathing through his mouth, he said, “It’s just easier”. As we sat in the cold, Dad noticed how serene Matthew looked.
They went back to bed and Matthew got in bed with Jennifer. About an hour later, Matthew was up again. This time, Jennifer took him outside for a while and then to the bathroom and ran hot water to create a steamy room. While they sat, she trimmed his toe nails. After about 30 min, they went back to bed with Matthew back in his own bed. They talked some in the night about breathing deeply and relaxing.
At 7:05, the alarm went off. Matthew awoke and asked Mom to turn it off. Mom told Matthew to keep sleeping and that she would get him later She then got Nathan ready for school While Matthew stayed in bed. Dad had awoken earlier than normal, had shoveled and had left around 6:45 after leaving separate notes for Nathan, Jennifer and Matthew. The bus for Nathan came at it’s usual time (~7:40 AM). Jennifer read the paper and heard Matthew get up to go to the bathroom around 8:00. He has a really heavy stop as he walks and it resonates through the house. She heard him flush, wash his hands, and stomp back.
She went up to shower around 8:30 because Matthew had a 9:20 appointment with the pediatrician to “check in.” When she looked in on Matthew, she noticed that his breathing was quiet. He was nicely tucked in under his covers. Perhaps the sickness had passed?, she thought. No, it was too quiet. He wasn’t breathing. She called 911 and began administering CPR. The ambulance came. They took over the CPR and started working on him and giving him injections. Eventually they took him to HCMC where a large team continued to work on him and look at his heart with an echocardiogram while a number of other staff looked on. Mike arrived at 9:30. Eventually, they had us come over and talk to him and hold his had as they continued to work on him. It was too late and he was pronounced dead shortly thereafter.
**Potentially related Sudden Death case: ** While it should be emphasized that lymphocytic myocarditis is very rare, we have come across several references where lymphocytic myocarditis is either the proposed cause of sudden death or have scenarios that suggest that it could have been the cause of death.
• Feb ’09. A 27 year old teacher died suddenly after suffering from cold/flu like systems the previous week. The doctor interviewed suggested that outer layer of her heart was inflamed and infected. Star Tribune Article
