The influence of the menstrual cycle on diameter and respiratory collapsibility of inferior vena cava in the population of young, healthy women – preliminary results

Introduction: Echocardiographic assessment of the interior vena cava (IVC) is part of the estimation of right atrial pressure. In young women values exceeding norm are observed. The aim of our study was an echocardiographic assessment of the IVC dimension depending on the phase of menstrual cycle among young, healthy women. Materials and methods: Female students of the Medical University of Gdańsk were enrolled into the study. Each patient underwent echocardiographic examination of the IVC diameter (d-IVC) and respiratory decrease in dimension in two time points, depending on the menstrual cycle phase: in the first days of menstruation (Phase M) or in the second part of menstrual cycle (Phase L). Results: 31 patients completed the study. There was a significant difference between the d-IVC in Phase M and Phase L (1.98±0.25cm vs 1.86±0.3cm; p <0.05). We did not observe correlation in terms of the inspiratory collapsibility. In the Phase M 77% patients achieved at least 50% decrease in dimension during inspiration comparing to 87% in Phase L (p=0.89). 35% patients had d-IVC exceeding reference values. Conclusion: In population of young women, the diameter of IVC exceeding reference values can be observed. IVC dimension depends on the menstrual cycle.