Cardiovascular Flashcards
(13 cards)
What is the recommend acclimation period for indirect blood pressure measurements?
7-14 days prior to beginning experiments
What site is commonly used in mice and rats for indirect blood pressure management?
Tail. Newer systems have been found to be comparable to invasive, telemetric systems.
How can direct arterial blood pressure be measured? Which are most accurate? Why?
Radiotelemetry devices, fluid filled catheters, or high-fidelity pressure transducers.
Indwelling catheters (fluid-filled and high-fidelity) most accurate due to ability to calibrate these over time.
Where can indwelling catheters be placed?
Atrial and ventricular chambers, large vessels such as the pulmonary artery and aorta.
What is a disadvantage of fluid-filled catheters?
Potential for infection at the skin exit site or intravascular infections. Can occlude due to clot or fibrin deposition at tip. Strict aseptic technique. Some infection complications reduced by attached catheter to SQ port and accessing via Huber needle.
Describe radiotelemetry devices.
Multifunctional units with gel-filled catheters that are placed intravascularly to monitor blood pressure. Have additional sensors for body temp, ECG, activity, and other parameters.
Describe the carotid artery loop procedure.
Used in sheep, cows, and horses. Externalizes the carotid artery.
In cardiopulmonary pathophysiology, the measurement of pressure in what artery is critical?
Pulmonary
Describe the carotid-jugular shunt.
Larger species, like sheep and goats. Polytetrafluorethylene (PTFE graft) is used in end-to-side anastomoses between jugular vein and carotid. Venous anastomosis usually first, then to carotid. Graft implant SQ in cranial portion of neck and skin closed.
Serves as access site for repeated blood samples and chronic vascular access. Has been used to develop a volume volume overload hypertrophic cardiomyopathy and left ventricular hypertrophy models.
Describe microangiography.
Blood vessels are visualized by the use of roentgen contrast medium and microradiographic techniques. Vessel is accessed, ground barium sulfate is perfused, and rapid film microradiographic techniques are employed.
What type of contrast compounds are cleared very rapidly in rodents? What is used instead? What is a disadvantage of these compounds?
Iodinated compounds cleared so rapidly that the first pass of a contrast media bolus cannot be visualized.
Blood-pool contrast agents that bind to plasma proteins have longer duration in blood. Have a lower level of contrast, so only useful for vessels of large caliber.
How can the lifespan of radiotelemetry devices be expanded?
Batteries that can be magnetically turned on and off.
Where are radiotelemetry devices typically placed?
SQ or IP
