Evaluating Systolic and Diastolic Cardiac Function in Rodents Using Microscopic Computed Tomography.

Area of Science:

• Cardiovascular Imaging
• Preclinical Research
• Pulmonary Hypertension

Background:

• Microscopic computed tomography (micro-CT) has not been previously used to assess cardiac functional parameters in small animals.
• Pulmonary arterial hypertension (PAH) is a severe condition affecting the heart's pumping ability.
• Assessing RV diastolic filling and systolic emptying is crucial for understanding PAH progression.

Purpose of the Study:

• To evaluate the utility of micro-CT for assessing RV diastolic filling and systolic emptying dynamics.
• To investigate cardiac function in an experimental model of pulmonary arterial hypertension using micro-CT.
• To establish a novel imaging method for preclinical cardiovascular research.

Main Methods:

• Wistar-Kyoto rats were induced with pulmonary arterial hypertension using SU5416 and chronic hypoxia.
• Multiphase cine cardiac images were acquired using micro-CT with a blood-pool contrast agent.
• Functional parameters of RV systolic ejection and diastolic filling were calculated from the 3D images.

Main Results:

• Micro-CT confirmed severe pulmonary arterial hypertension in the SU5416-hypoxia rat model.
• Significant decreases in RV peak ejection rate and RV peak filling rate were observed.
• Increased time to peak filling rate and total filling time indicated impaired diastolic function.
• Micro-CT RV diastolic indices showed excellent correlation with invasively derived RV end-diastolic pressure.

Conclusions:

• Microscopic computed tomography provides a novel method for assessing cardiac functional parameters in small animal models.
• This technique enables rapid and accurate evaluation of ventricular dynamics, particularly in pulmonary arterial hypertension.
• The developed method supports more extensive preclinical cardiovascular research.