Influence of Menstrual Cycle on P Wave Dispersion

Abstract

SummaryFemale gender is an independent risk factor for some types of arrhythmias. We sought to determine whether the menstrual cycle affects P wave dispersion, which is a predictor of atrial fibrillation. The study population consisted of 59 women in follicular phase (mean age, 29.3 ± 7.7 years) (group F) and 53 women in luteal phase (mean age, 28.1 ± 6.8 years) (group L). The ECGs of 35 patients (mean age, 26.4 ± 4.5) were obtained in both follicular and luteal phase. Both groups underwent a standard 12-lead surface electrocardiogram recorded at 50 mm/s. Maximal (Pmax) and minimal P wave durations (Pmin) were measured. P wave dispersion (PD) was defined as the difference between Pmax and Pmin. PD was significantly higher in group L than group F (46.6 ± 18.5 versus 40.1 ± 12.7; P < 0.05). Pmin was significantly lower in group L than group F (51.6 ± 12.1 versus 59.1 ± 12.1; P = 0.002). When we compared ECGs in different phases of the 35 patients, PD was significantly higher in luteal phase than follicular phase (53.2 ± 12.3 versus 42.8 ± 10.2; P < 0.05). Pmin was significantly lower in luteal phase than follicular phase (47.6 ± 6.6 versus 56 ± 10.1; P = 0.05). We detected a significant correlation between the day of the menses and PD (r = 0.27; P < 0.05). PD was increased in luteal phase compared to follicular phase, and this difference was more prominent as the days of the cycle progressed. (Int Heart J 2011; 52: 23-26)Key words: Menstrual cycle, P wave dispersion, Atrial fibrillation I t is well known that female sex hormones have proarrhythmic potential and female gender is an independent risk factor for some types of cardiac arrhythmias, such as congenital and acquired long QT syndrome and torsades de pointes. There are dynamic fluctuations in QT interval and torsade de pointes risk during the menstrual cycle and pregnancy.1) This hormonal flux that occurs during premenstrual, perimenopausal, and pregnancy periods could lead to ventricular tachycardia (VT) initiation in female patients with VT originating from the right ventricular outflow tract.2) P wave abnormalities, detected in the electrocardiogram (ECG), have been thought to reflect left atrial enlargement, 3) left atrial hypertension 4) and altered conduction. 5) A simple ECG marker, P wave dispersion (PD), has been used to evaluate the intraatrial and interatrial conduction times and the inhomogeneous propagation of sinus impulses which are well known electrophysiologic characteristics of the atrium prone to fibrillation.6,7) Prolonged P wave duration and PD have been reported to represent an increased risk for atrial fibrillation (AF) in patients with no underlying heart disease. 6,7)The relationships between menstrual cycle and different kinds of arrhythmias have been studied before, but there are no data on P wave abnormalities in the menstrual cycle. The aim of this study was to investigate the effects of the menstrual cycle on P wave dispersion. MethodsA total of 112 female patients between 15-49 years old (mean age, 28.7 ± 7.3 years old) with re...

Effects of reproductive period duration and number of pregnancies on midlife ECG indices: a secondary analysis from the Women’s Health Initiative Clinical Trial

“…Indeed, prior studies have assessed P-wave parameters throughout the menstrual cycle and noted that P-wave duration is substantially increased in the luteal phase. 24 Among women who did report taking prior hormone therapy, we observed a very modest but significant increase in midlife PR interval and in P-wave duration. Exogenous hormone therapy use may obscure the relationship between endogenous hormone exposure from a longer reproductive period duration and P-wave parameters, which would explain our findings of effect modification by hormone therapy use.…”

Analysis of the Effect of Menstrual Cycle Phases on Aerobic-Anaerobic Capacity and Muscle Strength

“…Various studies have shown that due to hormonal fluctuations in the organism during menstrual cycle, there may occur changes in aerobic, anaerobic and muscle strength. In addition, various authors have researched and are still continuing to research whether different phases of menstrual cycle have an influence on risk of injury (Beynonn et al, 2006), anaerobic power (Tsampoukos et al, 2010), sport performance (Oosthuyse et al, 2010), muscle strength (Loureiro et al, 2011), flexibility (Bell et al, 2009) and cardiovascular mechanisms (Bai et al, 2009;Fu et al, 2010;Karabag et al, 2011). Indeed, while some studies have shown that menstrual cycle phases influence sportive performance (Jaffre et al, 2006;Gordon et al, 2013), other studies show that these phases do not have an influence on performance (Giacomoni et al, 2000;Smekal et al, 2007).…”

P-wave parameters and cardiac repolarization indices: Does menopausal status matter?

“…There was a significant correlation between the day of menstrual cycle and P d . But no correlation existed between age, estrogen, progesterone levels, and P d measurements [42]. In an experimental study, 17beta-estradiol was administered to dogs and atrial pacing of 800 min −1 was performed and effective refractory periods (ERP) were evaluated.…”