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Development of an Ex Vivo, Beating Heart Model for CT Myocardial Perfusion.

Pelgrim GJ, Das M, Haberland U, Slump C, Handayani A, van Tuijl S, Stijnen M, Klotz E, Oudkerk M, Wildberger JE, Vliegenthart R - Biomed Res Int (2015)

Bottom Line: CT images did not show major artefacts due to interference of the model setup.During most of the experiment, blood flow was 0.9-1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg.An adapted Langendorff porcine heart model is feasible in a CT environment.

View Article: PubMed Central - PubMed

Affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Department of Radiology, Hanzeplein 1, 9713 GZ Groningen, Netherlands.

ABSTRACT

Objective: To test the feasibility of a CT-compatible, ex vivo, perfused porcine heart model for myocardial perfusion CT imaging.

Methods: One porcine heart was perfused according to Langendorff. Dynamic perfusion scanning was performed with a second-generation dual source CT scanner. Circulatory parameters like blood flow, aortic pressure, and heart rate were monitored throughout the experiment. Stenosis was induced in the circumflex artery, controlled by a fractional flow reserve (FFR) pressure wire. CT-derived myocardial perfusion parameters were analysed at FFR of 1 to 0.10/0.0.

Results: CT images did not show major artefacts due to interference of the model setup. The pacemaker-induced heart rhythm was generally stable at 70 beats per minute. During most of the experiment, blood flow was 0.9-1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg. Blood flow decreased and arterial pressure increased by approximately 10% after inducing a stenosis with FFR ≤ 0.50. Dynamic perfusion scanning was possible across the range of stenosis grades. Perfusion parameters of circumflex-perfused myocardial segments were affected at increasing stenosis grades.

Conclusion: An adapted Langendorff porcine heart model is feasible in a CT environment. This model provides control over physiological parameters and may allow in-depth validation of quantitative CT perfusion techniques.

No MeSH data available.


Related in: MedlinePlus

From the venous reservoir (VR), the blood first passed the cardiac pump CP. Then, the blood was pumped through the blood filter (BF) into the oxygenator (OX) and, from there, through the aorta into the coronary arteries. The setup was placed on the scanner table; all parts which could possibly interfere with the signal were placed outside the field of view.
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fig1: From the venous reservoir (VR), the blood first passed the cardiac pump CP. Then, the blood was pumped through the blood filter (BF) into the oxygenator (OX) and, from there, through the aorta into the coronary arteries. The setup was placed on the scanner table; all parts which could possibly interfere with the signal were placed outside the field of view.

Mentions: After preparation, the aorta and pulmonary artery were connected to the circulation loop using the cannulas (Figure 1). A bed of flexible cloth provided epicardial suspension. The heart was aligned in the scanner in supine position. A modified Langendorff perfusion model was used, with an artificial heart-lung loop. In 1895, Langendorff et al. proposed a model of retrograde perfusion of mammalian hearts in which a Krebs-Henseleit solution circulated via the aorta [10, 11]. This Langendorff model was refined by circulation of whole blood [12]. Whole blood was pumped by a centrifugal pump (BioMedicus, Medtronic, Minneapolis, MN, USA) from a venous reservoir into the aorta towards the aortic sinus and the coronary arteries. The flow in the coronaries is pulsatile and pressure dependent. A pressure is present at the aortic root, causing the flow of blood into the coronaries. When the myocardium contracts during systole, the coronary vasculature is compressed and therefore the vascular resistance increases, resulting in reduced coronary flow. During diastole the myocardium relaxes, which opens the vascular bed and thereby lowers vascular resistance with higher coronary flow as a result. In a normally functioning heart, the aortic blood pressure pulse varies in pressure between 120 and 80 mmHg, resulting in a pressure pulse of 40 mmHg. However, in the Langendorff experiments the pressure pulse is only in the order of magnitude of 10 mmHg.


Development of an Ex Vivo, Beating Heart Model for CT Myocardial Perfusion.

Pelgrim GJ, Das M, Haberland U, Slump C, Handayani A, van Tuijl S, Stijnen M, Klotz E, Oudkerk M, Wildberger JE, Vliegenthart R - Biomed Res Int (2015)

From the venous reservoir (VR), the blood first passed the cardiac pump CP. Then, the blood was pumped through the blood filter (BF) into the oxygenator (OX) and, from there, through the aorta into the coronary arteries. The setup was placed on the scanner table; all parts which could possibly interfere with the signal were placed outside the field of view.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4491382&req=5

fig1: From the venous reservoir (VR), the blood first passed the cardiac pump CP. Then, the blood was pumped through the blood filter (BF) into the oxygenator (OX) and, from there, through the aorta into the coronary arteries. The setup was placed on the scanner table; all parts which could possibly interfere with the signal were placed outside the field of view.
Mentions: After preparation, the aorta and pulmonary artery were connected to the circulation loop using the cannulas (Figure 1). A bed of flexible cloth provided epicardial suspension. The heart was aligned in the scanner in supine position. A modified Langendorff perfusion model was used, with an artificial heart-lung loop. In 1895, Langendorff et al. proposed a model of retrograde perfusion of mammalian hearts in which a Krebs-Henseleit solution circulated via the aorta [10, 11]. This Langendorff model was refined by circulation of whole blood [12]. Whole blood was pumped by a centrifugal pump (BioMedicus, Medtronic, Minneapolis, MN, USA) from a venous reservoir into the aorta towards the aortic sinus and the coronary arteries. The flow in the coronaries is pulsatile and pressure dependent. A pressure is present at the aortic root, causing the flow of blood into the coronaries. When the myocardium contracts during systole, the coronary vasculature is compressed and therefore the vascular resistance increases, resulting in reduced coronary flow. During diastole the myocardium relaxes, which opens the vascular bed and thereby lowers vascular resistance with higher coronary flow as a result. In a normally functioning heart, the aortic blood pressure pulse varies in pressure between 120 and 80 mmHg, resulting in a pressure pulse of 40 mmHg. However, in the Langendorff experiments the pressure pulse is only in the order of magnitude of 10 mmHg.

Bottom Line: CT images did not show major artefacts due to interference of the model setup.During most of the experiment, blood flow was 0.9-1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg.An adapted Langendorff porcine heart model is feasible in a CT environment.

View Article: PubMed Central - PubMed

Affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Department of Radiology, Hanzeplein 1, 9713 GZ Groningen, Netherlands.

ABSTRACT

Objective: To test the feasibility of a CT-compatible, ex vivo, perfused porcine heart model for myocardial perfusion CT imaging.

Methods: One porcine heart was perfused according to Langendorff. Dynamic perfusion scanning was performed with a second-generation dual source CT scanner. Circulatory parameters like blood flow, aortic pressure, and heart rate were monitored throughout the experiment. Stenosis was induced in the circumflex artery, controlled by a fractional flow reserve (FFR) pressure wire. CT-derived myocardial perfusion parameters were analysed at FFR of 1 to 0.10/0.0.

Results: CT images did not show major artefacts due to interference of the model setup. The pacemaker-induced heart rhythm was generally stable at 70 beats per minute. During most of the experiment, blood flow was 0.9-1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg. Blood flow decreased and arterial pressure increased by approximately 10% after inducing a stenosis with FFR ≤ 0.50. Dynamic perfusion scanning was possible across the range of stenosis grades. Perfusion parameters of circumflex-perfused myocardial segments were affected at increasing stenosis grades.

Conclusion: An adapted Langendorff porcine heart model is feasible in a CT environment. This model provides control over physiological parameters and may allow in-depth validation of quantitative CT perfusion techniques.

No MeSH data available.


Related in: MedlinePlus