Cross-sectional area and volume compliance of porcine left coronary arteries

2001 ◽  
Vol 281 (2) ◽  
pp. H623-H628 ◽  
Author(s):  
G. S. Kassab ◽  
S. Molloi

We have determined the cross-sectional area (CSA) compliance of the first several generations of pig coronary arteries and the volume compliance of the coronary arterial tree (vessels >0.5 mm in diameter) using a videodensitometric technique. The coronary arteries of four KCl-arrested maximally vasodilated pig hearts were perfused with iodine and 3% Cab-O-Sil. Because Cab-O-Sil occludes small arteries, the flow can be stopped and the pressure can be maintained while the trunk of the coronary artery and its subbranches are imaged using digital angiography. The coronary arteries were preconditioned several times with cyclic changes in pressure from 0 to 160 mmHg. The pressure was then varied in a triangular pattern, and the absolute CSA of each vessel and the total arterial volume were calculated using videodensitometry in conjunction with digital subtraction angiography. Our results have shown that the pressure-diameter and pressure-volume relationships are linear in the 60–140 mmHg pressure range. Furthermore, the compliance of the coronary arteries is small; i.e., the diameter of the coronary artery changes by <15% in the 80-mmHg pressure range. The compliance data couples the mechanics of the blood vessel wall to the mechanics of blood flow to yield a pressure-flow relationship for each coronary arterial segment.

2020 ◽  
Author(s):  
Mengyang Cong ◽  
Xingming Xu ◽  
Jianfeng Qiu ◽  
Shun Dai ◽  
Chuanzhi Chen ◽  
...  

Abstract Background: The Anomalous origin of the Right Coronary Artery (RCA) from the Left Coronary artery sinus(AORL) is one of the abnormal origins of the coronary arteries. Most of these issues seldom have effects on human health, but some individuals may have symptoms such as myocardial ischaemia or even sudden death. Recently, researchers are studying AORL through clinical cases, but study based on computational fluid dynamics (CFD) is rarely seen. In this study, haemodynamic changes between normal origin of the RCA and AORL are compared according to numerical simulation results.Methods: Realistic three-dimensional models of 16 normal right coronary arteries and 26 abnormal origins of the right coronary arteries were reconstructed, respectively. The blood flow was numerically simulated using software ANSYS. This study involves one-way fluid-solid coupling finite element model in which the blood is assumed to be incompressible Newtonian fluid, and the vessel is assumed to be isotropic, linear elastic material.Results: The differences of the cross-sectional area at the inlet between the normal group and the abnormal group was significant ( P <0.0001). There were significant differences in the volumetric flow ( P <0.0001) and the pressure ( P =0.0001). There were positive correlations with the ratio of the cross-sectional area of the RCA to the inlet area of the ascending aorta (AAO) and the ratio of the inlet volumetric flow of the RCA to the volumetric flow of the AAO, in both the normal ( P =0.0001, r=0.8198) and abnormal ( P =0.0199, r=0.4925) group.Conclusion: This study shows that the cross-sectional area of the inlet of AORL may cause ischaemia symptoms, and the results may contribute to the further understanding of the clinical symptoms of AORL based on the haemodynamics.


2003 ◽  
Vol 285 (2) ◽  
pp. H653-H660 ◽  
Author(s):  
Leila H. Hamza ◽  
Quang Dang ◽  
Xiao Lu ◽  
Ayesha Mian ◽  
Sabee Molloi ◽  
...  

The objective of this study was to determine the effect of passive myocardium on the coronary arteries under distension and compression. To simulate distension and compression, we placed a diastolic-arrested heart in a Lucite box, where both the intravascular pressure and external (box) pressure were varied independently and expressed as a pressure difference (ΔP = intravascular pressure – box pressure). The ΔP-cross-sectional area relationship of the first several generations of porcine coronary arteries and the ΔP-volume relationship of the coronary arterial tree (vessels >0.5 mm in diameter) were determined using a video densitometric technique in the range of +150 to –150 mmHg. The vasodilated left anterior descending (LAD) coronary artery of six KCl-arrested hearts were perfused with iodine and 3% Cab-O-Sil. The intravascular pressure was varied in a triangular pattern, whereas the absolute cross-sectional area of each vessel and the total arterial volume were calculated using video densitometry under different box pressures (0, 50, 100, and 150 mmHg). In the range of positive ΔP, we found that the compliance of the proximal LAD artery in situ (4.85 ± 3.8 × 10–3 mm2/mmHg) is smaller than that of the same artery in vitro (16.5 ± 6 × 10–3 mm2/mmHg; P = 0.009). Hence, the myocardium restricts the compliance of the epicardial artery under distension. In the negative ΔP range, the LAD artery does not collapse, whereas the same vessel readily collapses when tested in vitro. Hence, we conclude that myocardial tethering prevents collapse of large blood vessel under compression.


2020 ◽  
Author(s):  
mengyang cong ◽  
Xingming Xu ◽  
Jianfeng Qiu ◽  
Shun Dai ◽  
Chuanzhi Chen ◽  
...  

Abstract Background: The Anomalous origin of the Right Coronary Artery (RCA) from the Left Coronary artery sinus(AORL) is one of the abnormal origins of the coronary arteries. Most of these issues seldom have effects on human health, but some individuals may have symptoms such as myocardial ischaemia or even sudden death. Recently, researchers are studying AORL through clinical cases, but study based on computational fluid dynamics (CFD) is rarely seen. In this study, haemodynamic changes between normal origin of the RCA and AORL are compared according to numerical simulation results.Methods: Realistic three-dimensional models of 16 normal right coronary arteries and 26 abnormal origins of the right coronary arteries were reconstructed, respectively. The blood flow was numerically simulated using software ANSYS. This study involves one-way fluid-solid coupling finite element model in which the blood is assumed to be incompressible Newtonian fluid, and the vessel is assumed to be isotropic, linear elastic material. Results: The differences of the cross-sectional area at the inlet between the normal group and the abnormal group was significant (P<0.0001). There were significant differences in the volumetric flow (P=0.0001) and pressure (P=0.0002). There were positive correlations with the ratio of the cross-sectional area of the RCA to the inlet area of the ascending aorta (AAO) and the ratio of the inlet volumetric flow of the RCA to the volumetric flow of the AAO, in both the normal (P=0.0001, r=0.8178) and abnormal (P=0.0033, r=0.6107) group.Conclusion: This study shows that the cross-sectional area of the inlet of AORL may cause ischaemia symptoms, and the results may contribute to the further understanding of the clinical symptoms of AORL based on the haemodynamics.


1990 ◽  
Vol 20 (4) ◽  
pp. 748
Author(s):  
Doo Hong Choi ◽  
Hak Sun Kim ◽  
Sun Ho Chang ◽  
Joo Young Cho ◽  
Sung Gu Kim ◽  
...  

1994 ◽  
Vol 12 (9) ◽  
pp. 1886-1889 ◽  
Author(s):  
C J Watling ◽  
D H Lee ◽  
D R Macdonald ◽  
J G Cairncross

PURPOSE We studied corticosteroid-induced magnetic resonance (MR) scan changes in patients with recurrent malignant glioma to determine if corticosteroid therapy started concurrently with investigational treatment might yield false-positive responses. PATIENTS AND METHODS Ten symptomatic patients not on corticosteroids when malignant glioma recurred had a baseline MR scan performed before corticosteroid treatment, followed by serial scans at weekly intervals for 1 month while on dexamethasone (16 mg/d). The maximum cross-sectional areas and volumes of the gadolinium-enhancing regions (tumor) and T2-weighted abnormalities (tumor plus edema) were compared quantitatively and qualitatively for each series of scans. RESULTS Nine of 10 patients (90%) had a measurable reduction in the size of the gadolinium-enhancing region or T2-weighted abnormality with corticosteroid treatment. The maximum cross-sectional area and volume of the gadolinium-enhancing region decreased by at least 25% in three of 10 patients (30%). The maximum cross-sectional area and volume of the T2-weighted abnormality decreased by at least 25% in five of 10 patients (50%). Maximum measurable radiologic improvement was evident within 2 weeks in most patients. MR scans were judged improved by the reporting neuroradiologist in seven of 10 (70%). These subjective visual improvements were also evident within 2 weeks, but generally described as slight or modest. CONCLUSION Corticosteroid-induced MR scan reductions in tumor size may confound the assessment of response of recurrent malignant gliomas to investigational agents. For patients who start corticosteroids for symptom control, investigational treatment should be delayed until a new baseline MR image is established 2 weeks later. Response is then judged by comparing subsequent MR scans with the new corticosteroid-influenced baseline image.


Resuscitation ◽  
2005 ◽  
Vol 64 (2) ◽  
pp. 219-226 ◽  
Author(s):  
Volker Wenzel ◽  
Karl B. Kern ◽  
Ronald W. Hilwig ◽  
Robert A. Berg ◽  
Severin Schwarzacher ◽  
...  

2002 ◽  
Vol 282 (6) ◽  
pp. H2216-H2223 ◽  
Author(s):  
Stephan Windecker ◽  
Yves Allemann ◽  
Michael Billinger ◽  
Tilmann Pohl ◽  
Damian Hutter ◽  
...  

In eight healthy male volunteers (cardiologists; age 36 ± 5 yr), bicycle spiroergometry, Doppler echocardiography, and quantitative coronary angiography with intracoronary Doppler measurements before and after completion of a physical endurance exercise program of >5 mo duration were performed. Maximum oxygen uptake increased from 46 ± 6 to 54 ± 5 ml · kg−1 · min−1( P = 0.04), maximum ergometric workload changed from 3.8 ± 0.3 to 4.4 ± 0.3 W/kg ( P = 0.001), and left ventricular mass index increased from 82 ± 18 to 108 ± 29 g/m2 ( P = 0.001). The right, left main, and left anterior descending coronary artery cross-sectional area increased significantly in repsonse to exercise. Before versus at the end of the exercise program, flow-induced left anterior descending coronary artery cross-sectional area was 10.1 ± 3.5 and 11.0 ± 3.9 mm2, respectively ( P = 0.03), nitroglycerin-induced left coronary calibers increased significantly, and coronary flow velocity reserve changed from 3.8 ± 0.8 to 4.5 ± 0.7 ( P = 0.001). Left coronary artery correlated significantly with ventricular mass and maximum oxygen uptake, and coronary flow velocity reserve was significantly associated with maximum workload.


Sign in / Sign up

Export Citation Format

Share Document