Cardiac Dimensions and Function Are Not Altered among Females with the Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Iversen et al. 2020

[John Mac]

Abstract
Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition associated with several negative health outcomes.
A hallmark of ME/CFS is decreased exercise capacity and often profound exercise intolerance.

The causes of ME/CSF and its related symptoms are unknown, but there are indications of a dysregulated metabolism with impaired glycolytic vs oxidative energy balance.

In line with this, we recently demonstrated abnormal lactate accumulation among ME/CFS patients compared with healthy controls after exercise testing.

Here we examined if cardiac dimensions and function were altered in ME/CFS, as this could lead to increased lactate production.

Methods:
We studied 16 female ME/CFS patients and 10 healthy controls with supine transthoracic echocardiography, and we assessed cardiac dimensions and function by conventional echocardiographic and Doppler analysis as well as novel tissue Doppler and strain variables.

Results:
A detailed analyses of key variables of cardiac dimensions and cardiac function revealed no significant differences between the two study groups.

Conclusion:
In this cohort of well-described ME/CFS patients, we found no significant differences in echocardiograp

https://www.mdpi.com/2227-9032/8/4/406

 

[rvallee]

I wonder why echocardiographs. They don't seem to show anything for Long Covid either, only MRIs show something.

 

[ME/CFS Skeptic]

Strange that the paper doesn't provide a power calculation.

With only 16 patients the study was powered to find only large differences. So an evident explanation for a lack of differences may simply that there were too little participants to be able to detect moderate and small differences.

 

[Snowdrop]

Can't recall anymore where I read it but seems for some with ME there is an issue of long QT syndrome. Apparently it's super rare so that could translate into not looked for among the people affected. As in people who've been told they don't need tests because the issue is physical but mental.

 

[andypants]

Agree with the comments above re: sample size and methodology.

I do however appreciate the effort to narrow down possible explanations for the increase in lactate. I wish more researchers would do this type of work (and do it better).

 

[Forbin]

Can't recall anymore where I read it but seems for some with ME there is an issue of long QT syndrome.

That would be an interesting relationship.

FWIW, a genetic form of long QT syndrome may be rare, but acquired/transient long QT syndrome may be more common. The acquired form can result from certain drugs, including certain classes of antibiotics. Also, low potassium and/or magnesium (hypokalemia / hypomagnesmia ) can result in a lengthening of the QT portion of the EKG. It's known to occur in alcoholics, presumably because alcoholism results in poor nutrition and increased urination, both of which can lead to a loss of electrolytes, including potassium and magnesium. It's dangerous because an excessively long QT interval can devolve into ventricular fibrillation.

 

[Milo]

The key word in this abstract is supine. They tested patients at rest, and horizontally. Would there be any change in cardiac function when tilted vertically? In which way cardiac function would be different when vertical, considering that orthostatic intolerance is present in just about 100% of patients?

eta: it should not be a surprise to find normal tests, particularly the most common tests, at rest.

i would suspect, if these researchers are bright and really curious, that this may be the first of several papers, with this first one ruling out the obvious and hopefully digging deeper in further papers.

 

[Mithriel]

I had a drug stopped because of the risk of long QT syndrome. I think it is also found in AIDS.

I did wonder how old the patients were and how long they had been ill. If the heart changes shape because it is struggling then the changes would become more pronounced over time. Dr Cheney found that all his patients had some diastolic heart failure except some teenagers.

I do not think we get sick or lactate problems because of heart changes, the heart changes are the result of the lactate problems or whatever is causing those.