Frustratingly, certain sectors of the medical profession remain intransigent in their opinion that Complex Regional Pain Syndrome (CRPS) is limited to the extremities.
The spread of CRPS
However, there is now considerable literature (for some of which see below) supporting the fact that CRPS does spread beyond the extremities. A good example of this is the regular complaint of abdominal pain in conjunction with urinary and/or bowel problems among those suffering CRPS in their lower limbs. It is now well recognised that this is commonly an area affected by the early spread of the condition from the lower extremities.
Recently, for the first time I have been involved in a case where a heart problem has been linked to CRPS. Just as with the abdominal symptoms mentioned above, it seems that this is quite common although, worryingly, many people remain undiagnosed.
Often, those suffering CRPS experience chest pain which is commonly mistaken for indigestion or worse, hypochondria. It has been shown that in many cases this chest pain is as a result of neuropathic pain emanating from the brachial plexus rather than from the heart itself.
However, studies have also shown that many people with CRPS are not only suffering an increased heart rate, but also decreased heart rate variability (HRV). A decreased HRV has been associated with a higher risk of death following a heart attack.
Why does CRPS affect the heart?
There are a number of interlinked theories as to how and why CRPS affects the heart, but a significant issue seems to be that the nerves to the heart muscle itself are fed from the Cardiac Plexus, which is full of sympathetic nerves. The sympathetic nervous system is a division of the autonomic nervous system which controls unconscious bodily functions, including the beating of the heart and blood flow. It is thought that symptoms of CRPS occur as a result of dysfunctional sympathetic nerves sending inappropriate messages to the brain. Therefore, in the same way that those dysfunctional nerves cause symptoms in your hand or foot, they can also cause symptoms in other organs, including your heart.
A large scale study in the Pain Clinic at Drexel University in Philadelphia resulted in some major findings in relation to the incidence of heart problems in those suffering CRPS. The study involved approximately 2,500 people who had been suffering CRPS for more than two years. The average (mean) duration of the CRPS in those studied was 6½ years.
The authors of the study concluded that those with CRPS had a significantly higher incidence of increased heart rate and decreased HRV than the control group. Further, since developing CRPS, around 10% of those studied described suffering unconsciousness or light-headedness, likely due to a fall in blood pressure.
The authors concluded that these cardiac issues were due to a general imbalance in the autonomic nervous system and “increased their susceptibility to sudden death.”
What are the lessons?
This study highlights the huge importance of diagnosing cardiac complications of CRPS at an early stage. Once diagnosed, at the very least the CRPS sufferer can be subject to regular cardiology reviews. However, with CRPS in itself presenting such a significant risk factor, the results of the study also highlight the importance of raising awareness among all CRPS sufferers of other (non-CRPS) risk factors for heart disease.
You may also be interested in the following articles:
Rasmussen JW, Grothusen JR, Rosso AL, Schwartzman RJ. “Atypical chest pain: evidence of intercostobrachial nerve sensitization in Complex Regional Pain Syndrome”. Pain Physician,Vol.12, No. 5, 2009, pp. E329-34.