Reliability and Validity of the Vicorder Device When Measuring Pulse Wave Velocity Within Chronic Stroke Patients

Overview

Stroke is a major global health problem and main cause of disability worldwide. Blood pressure control is important for good health in stroke patients. Measuring central blood pressure (the blood pressure which is found in the heart) and measuring the stiffness of your arteries will give practitioners, clinicians and researcher's important information over and above what is usually obtained from peripheral blood pressure in the arm. The most validated and most recognisable equipment for central blood pressure and arterial stiffness is the SphygmoCor XCEL. However, the Doppler Ultrasound is used more often in population-based studies and has been shown to be a precise and accurate measurement. Although these devices are validated, they both require a highly skilled operator and are quite time-consuming. As such, it is important to explore less operator dependent and time consuming devices, such as the Vicorder, as this could be essential for researchers and clinicians.Therefore, this study will investigate whether the Vicorder device is valid and reliable when measuring these outcomes and if so could be implemented in large research studies and potenially be used by clinicians.

Twenty stroke patients will be recruited for this study. Participants will take part in four seperate assessments (2 hours each) with a minimum of 24 hour recovery between each session. Before each assessment participants will undertake an overnight fast (only water is allowed to be consumed prior to the assessment). If required, participants will take their medication the morning of each assessment and this will be noted.During the first session participants will be randomised into either a supine or seated condition. Participants will rest in this posture for 15 minutes. Triplicate measures of peripheral blood pressure and pulse wave analysis will be measured using the SphygmoCor XCEL and Vicorder device. A 3-lead ECG will be placed on the participant and ultrasound measures will be taken at the carotid, brachial, femoral and posterior tibial artery. This will examine the caroid-femoral pulse wave velocity (cfPWV), brachial-femoral pulse wave velocity (bfPWV), brachial-ankle pulse wave velocity (baPWV) and femoral-ankle pulse wave velocity (faPWV). Following this, the Vicorder device will be used to measure these segments. All measures will be on both symptomatic and asymptomatic sides. This procedure will be repeated in a seperate session whereby individuals will be in the other posture. Session 3 and 4 will include participants resting for 15 minutes in a supine position. Triplicate measures of peripheral blood pressure and pulse wave analysis will be taken with the Vicorder. Followed by triplicate measures of cfPWV, bfPWV, baPWV and faPWV. This will be repeated in a seated position within the same session.