In our study, P-wave dispersion was similar between the groups, however, FM patients had higher QT and QTc dispersions than the control group. Although fibromyalgia patients presented with complaints of chest pain and palpitations, no arrhythmia or ischemic ST-T wave changes consistent with clinical symptoms were observed in the Holter ECG recordings.
Fibromyalgia is a chronic, non-inflammatory locomotor system disorder marked by common pain and sensitive points throughout the body and sleep disturbances, anxiety, back pain, chest pain, and palpitations. Although it is seen in 2% of the society, the diagnosis is delayed because the complaints concern more than one clinician. This period lasts for 2–3 years on average and the patients’ life quality decreases considerably. It is more common in women and in our study, it was observed in women with a rate of 73.3% (p = 0.032). Patients with FMS had an average age of 38.3 ± 6.3 years.
Sympathetic hyperactivation and parasympathetic dysfunction develop due to autonomic nervous system disorder. As a result of excessive stress, sleep disorders, tender points, and exercise intolerance develop . The etiology and pathogenesis of FMS are clarified yet, although central and peripheral nervous system disorders, immunological and hormonal anomalies, genetic predisposition, and psychiatric factors are considered to have a role . Serotonin, noradrenaline, dopamine, and endorphin levels in the brain are low in fibromyalgia patients, whereas substance P levels in the cerebrospinal fluid are high. Our study did not examine hormonal testing, but hematological and biochemical tests revealed no significant differences between the study and control groups (p > 0.005).
Chest pain and palpitations are examples of somatic complaints related to the cardiovascular system. Cohen et al. argued that physical fatigue and psychological stress increase the symptoms, while Furlan et al. reported that the symptoms increased with sympathetic hyperactivity during rest [6, 13]. The Covid-19 process, which included the results of both studies, showed that increased stress may worsen FMS symptoms and FMS may develop after covid-19 [14, 15, 16]. During the covid-19 process, many acute coronary syndromes have been observed due to increased stress . In addition, in the study of AL-Shamri et al., fibromyalgia was found at a high rate (18%) in patients with ischemic heart disease . Yunus et al. reported that FMS is more common in the elderly, women, and patients with anxiety . Sedentary lifestyle, increased prevalence of metabolic syndrome, high blood pressure levels, increased stress, high resting heart rate have been reported as the key causals for the increase in cardiovascular diseases (CVD) [20, 21, 22]. In our study, there was no significant difference in systolic blood pressure (p = 0.394), heart rate (p = 0.800), BMI (p = 0.770), or the rate of dyslipidemia (p = 0.133) between FM and control patients.
Patients usually complain of palpitations . Fluctuations in heart rate have been reported as a result of increased autonomic activity. However, there is conflicting information about the development of arrhythmia . Dogru et al. reported that sympathetic activity increased and the rate of supraventricular tachycardia increased compared to control patients . It has been reported that there is more palpitation at night than during the day, and therefore sleep disorders develop in patients . Dursun et al. emphasized that the heart rate did not change in women with FMS . Invasive (electrophysiological study) and noninvasive (P-wave and QT dispersions in ECG) methods can be used to determine atrial and ventricular conduction durations . We can easily predict the development of arrhythmia with the non-invasive method.
P-wave dispersion has an independent predictive value for PAF. Dogan et al. in patients with Behcet’s disease, Yavuzkır et al. in patients with RA, Ahlehoff et al. in Psoriasis reported that the P-wave dispersion duration due to inflammation was prolonged and the risk of developing atrial fibrillation increased [28, 29, 30]. In previous studies, changes in P-wave duration were longer in FM patients these findings support a greater risk of developing AF in the FM patient group . Sarıfakıoğlu et al. reported that the risk of AF increased in FM patients . In contrast, Kulshreshta et al. reported that cardiac autonomic function was normal and the risk of arrhythmia did not develop . We found that P-wave dispersion was the same in FM and control patients (p = 0.129), similar to the results of Yolbaş et al .
Arrhythmia and CVD mortality are both predicted by QT dispersion . Furthermore, QT dispersion duration is longer in several rheumatic diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), juvenile idiopathic arthritis, systemic sclerosis, and Behçet's disease, and CVD risk is higher. In our study, QTd, and QTcd were statistically significant between the groups (p < 0.05). Yolbaş et al. reported that QT dispersion was the same in FM patients and control patients .
Aşkın et al. performed an electrophysiological study (EPS) on FM patients who came with palpitations, and they did not find a relationship between complaints of palpitations and arrhythmia . Thus, they proved that the predictive power of arrhythmia development with a non-invasive method is low. Therefore, they did not feel the need to perform 24-hour Holter ECG monitoring in their study.
Holter ECG recording is the simplest method to reveal whether the risk of arrhythmia will develop in patients with a long duration of Pd, QTd, and QTcd. In our study, although QT and QTc dispersions were significant in the study group, no arrhythmia was found in the 24-hour ambulatory Holter ECG recordings (p = 0.182). Sinus tachycardia was observed in 4 patients in the study group and 5 in the control group. Only one patient in each group was observed with more than 10% premature atrial contraction.
It was difficult to establish a patient population according to exclusion criteria and the study was retrospective. In our study, the patient population was small. ECG and Holter-ECG data were analyzed, but an electrophysiological study was not performed. Cardiac magnetic resonance imaging was not performed for myocardial fibrosis and involvement.