Cardiac symptoms related to paroxysmal atrial fibrillation varied with menstrual cycle in a premenopausal woman

The Role of α7nAChR-Mediated Cholinergic Anti-Inflammatory Pathway in Vagal Nerve Regulated Atrial Fibrillation

The aim was to investigate the role of the α7nAChR-mediated cholinergic anti-inflammatory pathway in vagal nerve regulated atrial fibrillation (AF).18 beagles (standard dogs for testing) were used in this study, and the effective refractory period (ERP) of atrium and pulmonary veins and AF inducibility were measured hourly during rapid atrial pacing at 800 beats/minute for 6 hours in all beagles. After cessation of 3 hours of RAP, the low-level vagal nerve stimulation (LL-VNS) group (n = 6) was given LL-VNS and injection of salinne (0.5 mL/GP) into four GPs, the methyllycaconitine (MLA, the antagonist of α7nAChR) group (n = 6) was given LL-VNS and injection of MLA into four GPs, and the Control group (n = 6) was given saline into four GPs and the right cervical vagal nerve was exposed without stimulation. Then, the levels of the tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), acetylcholine (ACh), STAT3, and NF-κB proteins were measured. During the first 3 hours of RAP, the ERPs gradually decreased while the dispersion of ERPs (dERPs) and AF inducibility gradually increased in all three groups. During the last 3 hours of 6 hours' RAP in this study, the ERPs in the LL-VNS group were higher, while the dERPs and AF inducibility were significantly lower when compared with the Control and MLA groups at the same time points. The levels of ACh in the serum and atrium in the LL-VNS and MLA groups were higher than in the Control group, and the levels of TNF-α and IL-6 were higher in the Control and MLA groups than in the LL-VNS group. The concentrations of STAT3 in RA and LA tissues were higher in the LL-VNS group while those of NF-κB were lower.In conclusion, the cholinergic anti-inflammatory pathway mediated by α7nACh plays an important role in low-level vagal nerve-regulated AF.

Does the phase of the menstrual cycle really matter to anaesthesia?

The menstrual cycle is a physiological phenomenon that is accompanied by several hormonal fluctuations involving oestrogen and progesterone. Oestrogen and progesterone exert several physiological effects. There are many questions pertaining to the influence of the physiology of menstruation on anaesthesia. We attempted to find out whether the phase of the menstrual cycle can alter the physiological functions during anaesthesia, the perioperative management and outcomes. We performed a literature search in Google Scholar, PubMed and Cochrane databases for original and reviewed articles on the phases of the menstrual cycle and their relation to anaesthesia-related physiological parameters to find an answer to these questions. Many studies have shown that women, perimenstrually, may have increased pain perception, exacerbation of systemic diseases, vocal cord/peripheral oedema and post-operative nausea and vomiting (PONV). Some of the other notable findings in most studies were sleep disturbances in the luteal phase (LP), increased occurrence of PONV in the ovulatory phase and a lower requirement of intravenous sedative and anaesthetic drug requirements in the LP. We found contradictory results concerning pain perception and PONV in relation to the follicular and LPs. However, we found that literature regarding the phase of the menstrual cycle and the haemodynamic response to intubation, anaesthesia-induced hypnosis and perioperative blood loss is relatively scarce. Thus, there is a need to conduct good quality research on these topics.