Long-term power spectral analysis in angioedema: proposal of a translational approach

C1 inhibitor hereditary angioedema (C1-INH-HAE) is a rare disease characterized by self-limiting edema associated with localized vasodilation due to increased levels of bradykinin. Although an involvement of the autonomic nervous system has been demonstrated by means of the analysis of the heart period (HP) variability during remission, no evaluation of the cardiac autonomic profile in the prodromal phase and during an attack has been performed. We positioned a multiday electrocardiogram recorder in a C1-INH-HAE 46-years old female patient until an attack occurrence. The HP variability indices were computed in the day of the attack and in the day before, in the 4 hours preceding (PRE) and following the attack. We found that the index related to the vagal modulation directed to the sinus node increased in the PRE period during the day of the attack. This is explainable by the expected vasodilation linked to the release of bradykinin that is the main mediator of the attack. We conclude that the HP parameters linked to the vagal cardiac modulation could be exploited and tested in future studies as early markers of the angioedema attack. The possibility to predict the attack could be of interest in the development of drugs to prevent the attack itself.