Exercise Preconditioning to Protect Against Dialysis-induced Cardiac Injury

An echocardiogram will be completed pre-hemodialysis (HD) treatment and at peak hemodynamic stress (30 min before the end of HD treatment) at each of the four study sessions. Images will be captured in the left lateral position and standard apical 4, 2, and 3 chamber views will be recorded for analysis using automated speckle-tracking software (EchoPac, GE Healthcare)

Systolic blood pressure (SBP), Diastolic blood pressure (DBP) and mean arterial pressure (MAP) will be measured using an automated blood pressure monitor integrated into the dialysis machine. Values will be monitored throughout each study.

The CV Insight contact device is a non-invasive continuous hemodynamic real time monitoring system used to assess cardiovascular and respiratory status using percutaneous photoplethysmography. The device will be attached to the right of the patient's forehead midline, approximately 2.5 cm above the level of the nose pre-dialysis and will remain intact until the patient is disconnected from the dialysis machine at each study session. Once attached, baseline recording will be obtained, and hemodynamic data will be continuously captured.

The Finometer utilizes a finger-cuff method to detect beat-to-beat changes in digital arterial diameter using an infrared photoplethysmography. The time-averaged data is subsequently downloaded to a computer-based analysis program for analysis. The finger-cuff will be placed on the participant's index finger at each study visit and will remain in place throughout the entire study visit

Blood samples will be collected from the participants dialysis access. Before HD and at peak-stress of each study session, will be collected for biochemistry, proteomic analysis and translational approach.

Blood samples will be collected from the participants dialysis access. Before HD and at peak-stress of each study session for analysis of erythrocyte deformability which indicates microcirculation efficiency

Endothelial function is assessed by measuring the dilatory response of the brachial artery to increased blood flow generated by reactive hyperemia in the downstream forearm. At each study session participants are placed in the supine position and the brachial artery of the non-dominant arm, or the non-distended arm is scanned in longitudinal section using a 12 MHz linear transducer connected to a Vivid Q echograph (GE, USA) supplemented by an electrocardiogram (ECG).

Proteomic alterations in plasma are important in the inflammatory response to ischemia-reperfusion (IR) injury. Blood Samples (plasma) will be collected pre and peak dialysis at each study session for the analysis of changes induced by exercise preconditioning, with the aim of identifying new potential targets for cardio protection.