| 2-day CPET | |
|---|---|
 A CPET being administered |
A 2-day CPET is a cardiopulmonary exercise test given on two successive days to measure the effect of post-exertional malaise (PEM) on a patient's ability to exercise. [1] [2] PEM is a cardinal symptom of myalgic encephalomyelitis/chronic fatigue syndrome and is common in long COVID as well. [3]
Several differences have been found between people with and without ME/CFS, including people with other diseases or who are sedentary. On the first test, people with ME/CFS exhibit lower performance and heart rate, and on the second test, performance is even lower, while for controls, it is the same or slightly better. The largest decrease is in anaerobic threshold, which signifies a shift from aerobic to anaerobic metabolism at a lower level of exertion, and is not influenced by effort. [3] [1] [4] Peak power output, heart rate, and VO2max also decrease, and in ME/CFS, but effort and familiarity with the test may affect VO2max and power. [5] [3] Additionally, healthy people generally recover from a CPET within 24 hours while people with ME/CFS do not. [6]
A 2-day CPET can objectively measure PEM and its effect on physical functioning. [7] (Objective indicators of maximal effort during both tests control for effort.) [7] However, its utility has not been completely confirmed, as many studies of it have been small. [4] While it should not be required for a diagnosis, a 2-day CPET can show that symptoms are not due to deconditioning and provide evidence for obtaining disability benefits. [7] Because PEM is also a symptom of long COVID, the 2-day CPET may be useful in evaluating exercise intolerance there as well. [8]
The cause of decreased performance is not understood. Proposals include impaired oxygen transport, impaired aerobic metabolism, and mitochondrial dysfunction. [3]
The test provokes symptoms by design, and recovery may be prolonged. In some cases, it may worsen the illness long-term. [3] [7]
Fatigue describes a state of tiredness, exhaustion or loss of energy.
The ME Association is a UK health charitable organization that provides information, advocacy, and services to persons and families affected by ME/CFS, and raises funds for research into ME/CFS. It has been reported to be one of the two largest UK charities for ME/CFS.
Exercise intolerance is a condition of inability or decreased ability to perform physical exercise at the normally expected level or duration for people of that age, size, sex, and muscle mass. It also includes experiences of unusually severe post-exercise pain, fatigue, nausea, vomiting or other negative effects. Exercise intolerance is not a disease or syndrome in and of itself, but can result from various disorders.
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has a long history with an evolution in medical understanding, diagnoses and social perceptions.
Management of ME/CFS focuses on symptoms management, as no treatments that address the root cause of the illness are available. Pacing, or regulating one's activities to avoid triggering worse symptoms, is the most common management strategy for post-exertional malaise. Clinical management varies widely, with many patients receiving combinations of therapies.
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is an illness with a history of controversy. Although it is classified as an organic disease by a majority of researchers, it was historically assumed to be psychosocial, an opinion still held among many physicians. The pathophysiology of ME/CFS remains unclear, there exists many competing diagnostic criteria, and some proposed treatments are controversial. There is a lack of education and accurate information about the condition among a significant number of medical practitioners, which has led to substantiated accusations of patient neglect and harm.
Clinical descriptions of ME/CFS vary. Different groups have produced sets of diagnostic criteria that share many similarities. The biggest differences between criteria are whether post-exertional malaise (PEM) is required, and the number of symptoms needed.
The Lightning Process (LP) is a three-day personal training programme developed and trademarked by British osteopath Phil Parker. It makes unsubstantiated claims to be beneficial for various conditions, including ME/CFS, depression and chronic pain.
Graded exercise therapy (GET) is a programme of physical activity that starts very slowly and gradually increases over time, intended as a treatment for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Most public health bodies, including the CDC and NICE, consider it ineffective, and its safety is disputed. However, GET still enjoys support among a minority of clinicians and organizations.
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disabling chronic illness. People with ME/CFS experience profound fatigue that does not go away with rest, sleep issues, and problems with memory or concentration. Further common symptoms include dizziness, nausea and pain. The hallmark symptom is a worsening of the illness which starts hours to days after minor physical or mental activity. This "crash" can last from hours or days to several months.
Rosamund Vallings is a medical doctor, known as one of the leading authorities on Chronic Fatigue Syndrome (ME/CFS) in New Zealand.
Post-exertional malaise (PEM), sometimes referred to as post-exertional symptom exacerbation (PESE) or post-exertional neuroimmune exhaustion (PENE), is a worsening of symptoms that occurs after minimal exertion. It is the hallmark symptom of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and common in long COVID and fibromyalgia. PEM is often severe enough to be disabling, and is triggered by ordinary activities that healthy people tolerate. Typically, it begins 12–48 hours after the activity that triggers it, and lasts for days, but this is highly variable and may persist much longer. Management of PEM is symptom-based, and patients are recommended to pace their activities to avoid triggering PEM.
Idiopathic chronic fatigue (ICF) or chronic idiopathic fatigue or insufficient/idiopathic fatigue is a term used for cases of unexplained fatigue that have lasted at least six consecutive months and which do not meet the criteria for myalgic encephalomyelitis/chronic fatigue syndrome. Such fatigue is widely understood to have a profound effect on the lives of patients who experience it.
Pacing is an activity management technique for managing a long-term health condition or disability, aiming to maximize what a person can do while reducing, or at least controlling, any symptoms that restrict activity. Pacing is commonly used to help manage conditions that cause chronic pain or chronic fatigue.
DecodeME is an ongoing genome-wide association study searching for genetic risk factors for ME/CFS. With a planned recruitment of 25,000 patients, it is expected to be the largest such study to date. Recruitment closed on 15 November 2023 and results are expected in 2024.
Post-acute infection syndromes (PAISs) or post-infectious syndromes are medical conditions characterized by symptoms attributed to a prior infection. While it is commonly assumed that people either recover or die from infections, long-term symptoms—or sequelae—are a possible outcome as well. Examples include long COVID, Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and post-Ebola virus syndrome. Common symptoms include post-exertional malaise (PEM), severe fatigue, neurocognitive symptoms, flu-like symptoms, and pain. The pathology of most of these conditions is not understood and management is generally symptomatic.
Andrew Melvin Ramsay (1901–1990) was a British physician, who is known for his research and advocacy on myalgic encephalomyelitis (ME), a chronic disease causing muscle weakness and cognitive dysfunction. Ramsay worked as a consultant at the Royal Free Hospital in London during a mysterious 1955 disease outbreak of what later became known as ME. He studied the disease and similar outbreaks elsewhere. Work by Ramsay showed that although ME seldom caused death, the disease could be highly disabling.
Carmen Scheibenbogen is a German immunologist who is the acting director of the Institute for Medical Immunology of the Charité university hospital in Berlin. She specialises in hematology, oncology and immunology. She leads the Outpatient Clinic for Immunodeficiency and the Fatigue Centre at the Charité hospital. She is one of the few doctors specialised in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) in Germany, and also researches long COVID.
The PACE trial was a large and controversial trial which compared the effects of cognitive behavioural therapy (CBT), graded exercise therapy (GET), adaptive pacing therapy, and specialist medical care for people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
Chronotropic incompetence (CI) is the inability of heart rate to increase as expected in response to exercise. The condition can be defined in different ways and occurs in various diseases. Sufferers have a higher risk of cardiovascular disease and early death.
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