Tonometry and Duplex Ultrasound to Predict AAA Progression and CV Events in Aneurysm Patients (1-2-3 Trial)

The CAR test will be applied to stimulate the sympathetic nervous system. This thermal stimulus is known to elevate blood pressure via sympathetic pathways, so it can be used to study the vascular response to sympathetic activation. The participant will submerge their left hand in a bucket of ice water (approximately 4 degrees celsius) for 3 minutes, which is reported to be sufficient to induce a maximal dilation in the common carotid artery. At baseline and every minute after the hand is submerged in ice water, the blood pressure will be measured to check whether a sympathetic stimulation is achieved.

"The SphygmoCor device will be used to non-invasively measure arterial stiffness parameters using applanation tonometry. For Pulse Wave Analyses (PWA), the radial waveform will be recorded. Approximately 10 waveforms are averaged, resulting in several non-invasive parameters:~* Peripheral pressure parameters~* Central and abdominal aneurysm pressure parameters (derived using a transfer function)~* Cardiac output parameters (SEVR, ED)~Pulse wave velocity will be performed by recording the waveforms of the carotid and femoral artery sequentially. The travelled distance will be measured according to the current guidelines and entered in the program. The program will calculate the PWV based on 10 ECG triggered waveform of each artery."