Vasomotor reactivity (VMR) and autoregulation define the physiological compensatory mechanisms when flow is impaired. Identification of exhausted VMR can be a good indication for high risk for stroke.
VMR can be assessed with TCD under two specific conditions: hypercapnia or CO2 reactivity, and with intravenous injections of Acetazolamide or the Diamox test. Note that the Diamox test is not accepted in some countries.
Typically, an increase in peak velocities above 40% during induced increase in CO2 reflects intact VMR, whereas a smaller increase reflects different degrees of impaired VMR. Absence of flow increase reflects a complete exhaustion of the autoregulatory capacity.
The Viasonix Dolphin is ideally set with dedicated Unilateral and Bilateral protocols to determine the autoregulatory capacity of the cerebral circulation of the patient. Doppler waveforms are captured automatically during baseline, and peak (hypercapnia) and minimal (hypocapnia) flows for immediate evaluation, as well as a display of the blood flow fluctuations during entire test process. The respective parameters are automatically shown in a dedicated table with the VMR index readily displayed.
Disclaimer of Information & Content
The content of Viasonix Ltd. website is for information only, not advice or guarantee of outcome. Information is gathered and shared from reputable sources; however, Viasonix Ltd. Management is not responsible for errors or omissions in reporting or explanation. No individuals, including those under our active care, should use the information, resources or tools contained within this self-diagnosis or self-treat any health-related condition. Viasonix Ltd. Management gives no assurance or warranty regarding the accuracy, timeliness or applicability or the content.Contact us via email: [email protected]
Or using the form below.
Our team will respond back quickly!