Effect of arterial hypertension on intrinsic heart rate variability

• Grant number: 22/10912-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2023
• End date: October 31, 2024
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Hugo Celso Dutra de Souza
• Grantee: Giovanna Olmedo Consul Metidieri
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Introduction: Heart rate variability (HRV) is determined by physiological processes with different frequencies of occurrence. Among them, the sympathetic and parasympathetic autonomic components stand out. However, the heart also has intrinsic heart rate variability (iHRV) that can influence HRV and autonomic modulation on the heart. In this case, we suspect that cardiovascular diseases, such as hypertension, can modify the iHRV. Objectives: To investigate whether there are differences in the iHRV between normotensive and spontaneously hypertensive rats (SHR; spontaneously hypertensive rats), and the relationship with the autonomic modulation of HRV. Methods: 18-week-old rats will be studied (N=18), divided into two groups; a group of normotensive rats (N=09) and a group of hypertensive rats (N=09). The analysis of HRV will be performed by recording the intervals of heartbeats with the animals awake, before and after the double autonomic heart block with atropine and propranolol. In turn, the iHRV analysis will be performed using pulse interval recordings obtained with the Langendorff technique in an isolated heart. The variability analysis methodology will involve linear and non-linear methods.