Carbon Monoxide Heart Attack?

Am I Having a Carbon Monoxide Heart Attack?

Are these cardiac symptoms a carbon monoxide heart attack? It could be as carbon monoxide poisoning can cause a heart attack.

By Rebecca Martin

Imagine this scenario.  You call 911 because you are experiencing chest pains, shortness of breath, nausea and lightheadedness. An ambulance is dispatched. In the emergency room, the staff notes your age and prior health issues, and you are examined for what appears to be a heart attack, or more specifically, a myocardial infarction or MI.

A carbon monoxide heart attack, meaning a cardiac emergency cause by carbon monoxide poisoning, is a real possibility anytime CO ambient air levels get well above alarming thresholds. 

In the emergency room it is noted that your skin is cool and pale, indicative of vasoconstriction.  The heart is not receiving adequate oxygen. Subsequently you receive medication for myocardial infarction which can consist of anticlotting medications such as aspirin, clopidogrel, or heparin. You might receive oxygen to help the heart tissue or thrombolytic drugs to dissolve any clots. After observation you are sent home with instructions to follow up for more extensive testing with a specialist. You return home to a home where a killer is still lurking.

That killer is undetected carbon monoxide.

Myocardial infarction occurs when the blood flow to the heart is blocked, usually due to a buildup of fat, cholesterol, or any other plaque that occurs in the arteries feeding the heart. It is not uncommon for it to occur suddenly as it can sometimes exist as a “silent” disease which can go undetected until it causes a catastrophic event.  It typically attacks people at a more advanced age and around one million Americans suffer a myocardial infarction every year.

The problem is that myocardial infarction can occur secondary to carbon monoxide exposure and the carbon monoxide exposure may be missed in the emergency room. This can be directly linked to the initiation of the emergency call to 911 and the response of emergency workers at the scene who may have no cause to suspect that carbon monoxide may be present on the scene. Their response may be targeted to what appears to be a heart attack and all actions taken from that point dismiss the role carbon monoxide may have played during the incident. At the scene, with doors opened and the patient quickly removed, first responders would not be likely to notice the presence of carbon monoxide at the scene and the patient is delivered to the ER with a diagnostic suspicion that the patient has suffered a heart attack.

It is easy to diagnose carbon monoxide poisoning in the ER when there is evidence that a CO detector was alarming at the scene, or when multiple people at the scene are also exhibiting symptoms of carbon monoxide poisoning.  But in the absence of an obvious possible source of carbon monoxide, or other epidemiological evidence, first responders may not note carbon monoxide as a possible culprit in the incident.

Carbon monoxide has been proven to be able to rapidly escape a home upon arrival of first responders and is even capable of traveling through walls in multi-residence properties. So, even if first responders suspect that there may be toxic levels of carbon monoxide at the scene, the carbon monoxide may have dissipated prior to a portable detector being employed to detect its presence and levels may have dropped to levels considered acceptable at the time of testing. Because carbon monoxide is referred to as “the great imitator”, the symptoms are often mistaken for other causes, from flu to food poisoning, and in our case,  even heart attack.

The illusive nature of carbon monoxide poisoning can also work the other way. While much more study is needed to determine the precise relationship between carbon monoxide poisoning and myocardial infarction, it is noted that carbon monoxide poisoning can in fact, lead to myocardial infarction as a result of the toxic exposure.

Myocardial infarction is one of the complications that can occur following exposure to carbon monoxide.

“Cardiovascular complications of CO poisoning have been well reported and include myocardial stunning, left ventricular dysfunction, pulmonary edema, and arrhythmias. Acute myocardial ischemia has also been reported from increased thrombogenicity due to CO poisoning.”  https://pubmed.ncbi.nlm.nih.gov/24518173/#:~:text=Cardiovascular%20complications%20of%20CO%20poisoning,thrombogenicity%20due%20to%20CO%20poisoning.

Not only are heart complications possible after exposure to carbon monoxide. They can have long term effects.

“Myocardial toxicity from CO exposure is associated with increased short-term and long-term mortality.” https://pubmed.ncbi.nlm.nih.gov/24518173/#:~:text=Cardiovascular%20complications%20of%20CO%20poisoning,thrombogenicity%20due%20to%20CO%20poisoning.

In the absence of a clear diagnosis of carbon monoxide poisoning as the cause of abnormal heart function in the emergency room a patient is not likely to receive hyperbaric oxygen therapy.

“Diagnosis and treatment of carbon monoxide poisoning are important as such exposures, even after being removed from the source, can lead to fatal arrhythmias, and neurological deterioration. Persistent neurological symptoms have been reported to have marked improvement despite the late initiation of hyperbaric oxygen therapy as in the remarkable salvage of the survivor of the Sago (Chile) My disaster.” https://www.jems.com/patient-care/the-case-of-the-missing-carbon-monoxide/

Because the cardiovascular system and central nervous system have extremely high oxygen demands, lack of oxygen during and subsequent to carbon monoxide exposure, they are more likely to suffer from both the acute and delayed clinical features of carbon monoxide.

“Previous studies have focused on the cardiac dysfunction related to CO poisoning and indicated that myocardial injury is frequent in moderate-to-severe CO poisoning.”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4602477/#:~:text=CO%2Dpoisoned%20patients%20with%20coexisting,of%20subsequent%20development%20of%20arrhythmia.

Carbon monoxide produces damage at the cellular or sub cellular level in the heart. At this point in time there is not a specific treatment available other than oxygen.

“No specific treatment other than oxygen delivery can be advocated for cardiac toxicity at present, and 100% oxygen therapy should be continued until the patient is asymptomatic and carboxyhemoglobin levels decrease below 5-10.” https://www.sciencedirect.com/science/article/abs/pii/S0009912012002731

Obviously, this cannot occur if carbon monoxide exposure is not a concern in the emergency room and the patient is seen as a potential heart attack victim. So, while the patient may exhibit signs of a heart attack, carbon monoxide may still be working to cause further damage because the source of the damage has not been detected. As a result, this can lead to short term and long-term problems which impact the patient’s life expectancy. The patient is released after the immediate symptoms of a heart attack are addressed while the ongoing effects of carbon monoxide remain hidden. The patient can then be returned to the same environment which initiated the sequence of events as a result.

The solution lies in the same area that many other problems associated with carbon monoxide exist.

We talk about first responder safety at the scene and how important immediate carbon monoxide detection is at the scene. And we acknowledge that 911, first responders and the ER may not be made aware that carbon monoxide is the culprit in the absence of functioning carbon monoxide detectors, or we may not be made aware of just how toxic the environment was when entering a scene because of the quick dispersant which may not register on devices brought to the scene.

However, if all first responders were equipped with personal CO detectors, much of the uncertainty over improper assessment at the scene might be eliminated.

This would help optimize treatment in both instances; people treated for a heart attack without identifying carbon monoxide poisoning and people treated for carbon monoxide poisoning without looking at potential heart problems. Because of the high probability that both conditions can and do often exist in the same patient, it should become standard protocol to examine patients for both possibilities.

We first addressed this possibility more than a decade ago here.