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Abnormal cardiac pain perception in syndrome X
A Chauhan1, P A Mullins, S I Thuraisingham
1Regional Cardiac Unit, Papworth Hospital, Cambridge, England, United Kingdom.
Insights
Patients with syndrome X experience chest pain due to an abnormal cardiac pain perception, not altered coronary blood flow. This study highlights a diminished pain threshold as a key factor in syndrome X chest pain.
Area of Science:
- Cardiology
- Pain Perception Research
- Gastroenterology
Background:
- Syndrome X, also known as cardiac syndrome X, is characterized by chest pain despite normal coronary arteries.
- Previous reports suggest altered pain perception in patients with syndrome X.
Purpose of the Study:
- To investigate if a reduced cardiac pain threshold contributes to chest pain in patients diagnosed with syndrome X.
- To differentiate the role of pain perception versus coronary blood flow abnormalities in syndrome X.
Main Methods:
- Intracardiac catheter manipulation was performed on four patient groups, including syndrome X, mitral valve disease patients, and heart transplant recipients.
- Coronary flow velocity and coronary flow reserve in response to papaverine were measured in syndrome X patients and heart transplant recipients.
Main Results:
- Intracardiac stimulation induced typical anginal chest pain in 94% of syndrome X patients.
- Chest pain was significantly less frequent in control groups (mitral valve disease and heart transplant recipients).
- Coronary flow reserve was significantly lower in the syndrome X group, but coronary blood flow velocity did not change with chest pain.
Conclusions:
- Abnormal cardiac pain perception is a fundamental characteristic of syndrome X.
- The findings suggest that a diminished pain threshold, rather than altered coronary hemodynamics, is central to chest pain in syndrome X.
Objectives:
The purpose of this study was to determine whether a diminished cardiac pain threshold contributes to chest pain in patients with syndrome X.
Background:
There have been some reports of an altered pain perception in syndrome X.
Methods:
Intracardiac catheter manipulation was performed in four groups of patients (syndrome X [group 1, 36 patients]; mitral valve disease and normal coronary arteries [group 2, 36 patients]; mitral valve disease and coronary artery disease [group 3, 36 patients]; and heart transplant recipients with normal coronary arteries [group 4, 36 patients]). Coronary flow velocity was measured in patients with syndrome X and in transplant recipients by use of an intracoronary Doppler catheter positioned in the left anterior descending coronary artery at intracardiac catheter manipulation. Coronary flow reserve in response to papaverine was also measured in patients with syndrome X and in transplant recipients.
Results:
Intracardiac stimulation produced typical anginal chest pain in 34 group 1 (syndrome X) patients (94%). However, chest pain was produced only in five patients (14%) in group 2, seven patients (19%) in group 3 and no patients in group 4. There were no significant changes in coronary blood flow velocity associated with chest pain in group 1 patients. Coronary flow reserve in response to a hyperemic dose of intracoronary papaverine was significantly lower in the syndrome X group. There was no significant difference in the prevalence with which the stimulation tests produced chest pain in patients with syndrome X with an impaired coronary flow reserve or a positive radionuclide scan.
Conclusions:
The results of our study suggest that abnormal cardiac pain perception is a fundamental abnormality in syndrome X.