Cardiac arrhythmias during two different stages of the menstrual cycle

We have frequently observed that female patients report an association between their arrhythmias and their menstrual period but little is known about such an association. We studied 25 female patients 25.9+/-7.3 year-old with regular menstrual periods. Thirteen patients were evaluated because they suffered from cardiac symptoms and complained of arrhythmia aggravation during their menstrual period. Twelve normal female patients formed the control group. The evaluation was performed in a drug-free state. All the patients had a 24-h Holter study performed during the 7th day of their menstrual cycle and 3 days before the following menstrual period. No patient had sustained arrhythmia during the monitoring periods. When comparing the two Holter recordings we did not find statistically significant differences with respect to either the total count of supraventricular and ventricular premature beats or the heart rate.