Modelling coronary flow after the Norwood operation: Influence of a suggested novel technique for coronary transfer

Background: The dynamic behavior of the aortic sinuses has an important function in the specific characteristics of coronary blood flow. Several publications have confirmed suboptimal myocardial perfusion after the Norwood procedure. Our study was undertaken to confirm four hypotheses. First, we hypothesized that there is more resistance to coronary flow due to coronary attachments to hypoplastic aortic root and sinuses. Also, as the amalgamation of the ascending aorta with the pulmonary artery occurs above the aortic root, the coronary blood flow is not fully in antegrade pattern. Second, performing the Norwood with our modification i.e., coronary transfer to the well-developed sinuses of the pulmonary root will result in less resistance to flow and a full antegrade flow pattern. This may eventually improve the long term ventricular and survival outcomes. Third, our modification is applicable to all procedures where the pulmonary root supplies the systemic circulation e.g., Norwood, Damus–Kaye–Stansel (DKS), and Yasui operations, whether applied to single or biventricular repair. Fourth, with our modification, the effect of the type of shunt; Sano vs. Blalock Taussig (BT shunt) on the coronary flow after the Norwood will be mitigated. This will give the surgeon more freedom to which shunt to use, and may make the surgeon keener to perform the BT shunt in order to avoid the ventricular scar associated with the Sano shunt which will negatively impact the ventricular function. Methods: Computational fluid dynamic (CFD) simulations were performed to evaluate flow streamlines and to quantify flow distribution and total pressure drop in the coronary branches in both Norwood (pre-transfer) and modified Norwood (post-transfer) models. Comparisons between the two models were performed. Results: The systolic flow rate in all coronary branches was higher in the post-transfer model in the proportions of: left main 5%, left anterior descending (LAD) 6%, left circumflex (LCx) 3.5%, and right coronary artery (RCA) 7.2% higher flow rates. In diastole, pressure drop from the aortic inlet to distal left main and distal right main was substantially less in the post-transfer model. Conclusion: Post-transfer model has produced more favorable coronary hemodynamics in all coronary branches. As a result, performing our modification could potentially improve the long term ventricular and survival outcomes.

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976 Coronary blood flow and coronary flow reserve by contrast-enhanced transthoracic echocardiography predict long-term outcome in heart transplantation

European Journal of Echocardiography ◽

10.1016/s1525-2167(05)80584-0 ◽

2005 ◽

Vol 6 ◽

pp. S155-S155

Keyword(s):

Blood Flow ◽

Heart Transplantation ◽

Coronary Blood Flow ◽

Transthoracic Echocardiography ◽

Coronary Flow ◽

Term Outcome ◽

Long Term Outcome ◽

Flow Reserve ◽

Contrast Enhanced

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Contribution of extravascular compression to reduction of maximal coronary blood flow

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1992.262.1.h68 ◽

1992 ◽

Vol 262 (1) ◽

pp. H68-H77

Author(s):

F. L. Abel ◽

R. R. Zhao ◽

R. F. Bond

Keyword(s):

Blood Flow ◽

Coronary Blood Flow ◽

Coronary Flow ◽

Perfusion Pressure ◽

Left Ventricular Pressure ◽

Coronary Perfusion Pressure ◽

Left Ventricular ◽

Ventricular Pressure ◽

Coronary Perfusion ◽

Storage Site

Effects of ventricular compression on maximally dilated left circumflex coronary blood flow were investigated in seven mongrel dogs under pentobarbital anesthesia. The left circumflex artery was perfused with the animals' own blood at a constant pressure (63 mmHg) while left ventricular pressure was experimentally altered. Adenosine was infused to produce maximal vasodilation, verified by the hyperemic response to coronary occlusion. Alterations of peak left ventricular pressure from 50 to 250 mmHg resulted in a linear decrease in total circumflex flow of 1.10 ml.min-1 x 100 g heart wt-1 for each 10 mmHg of peak ventricular to coronary perfusion pressure gradient; a 2.6% decrease from control levels. Similar slopes were obtained for systolic and diastolic flows as for total mean flow, implying equal compressive forces in systole as in diastole. Increases in left ventricular end-diastolic pressure accounted for 29% of the flow changes associated with an increase in peak ventricular pressure. Doubling circumferential wall tension had a minimal effect on total circumflex flow. When the slopes were extrapolated to zero, assuming linearity, a peak left ventricular pressure of 385 mmHg greater than coronary perfusion pressure would be required to reduce coronary flow to zero. The experiments were repeated in five additional animals but at different perfusion pressures from 40 to 160 mmHg. Higher perfusion pressures gave similar results but with even less effect of ventricular pressure on coronary flow or coronary conductance. These results argue for an active storage site for systolic arterial flow in the dilated coronary system.

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Assessment of the Effect of Coronary Occlusion on Aortic Valve Dynamics Using a Global 3D FSI Model

ASME 2012 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2012-80395 ◽

2012 ◽

Author(s):

Soroush Nobari ◽

Rosaire Mongrain ◽

Richard Leask ◽

Raymond Cartier

Keyword(s):

Coronary Artery Disease ◽

Blood Flow ◽

Coronary Artery ◽

Coronary Blood Flow ◽

Aortic Root ◽

Calcific Aortic Stenosis ◽

Mortality And Morbidity ◽

Valve Dynamics ◽

Artery Disease ◽

Aortic Stiffening

Coronary artery disease (CAD) is considered to be a major cause of mortality and morbidity in the developing world. It has recently been shown that aortic root pathologies such as aortic stiffening and calcific aortic stenosis can contribute to the initiation and progression of this disease by affecting coronary blood flow [1,2]. Such pathologies influence the distensibility of the aortic root and therefore the hemodynamics of the entire region. As a consequence the coronary blood flow and velocity profiles will be altered [3,4,5] which could accelerate the development of an existing coronary artery disease. However, it would be very interesting to see if an occluded coronary artery would have a mutual impact on valvular dynamics and aortic root pathologies. This bi-directionality could aggravate and contribute to the progression of both the coronary and aortic root pathology.

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Computer Analysis of Coronary Doppler Flow Velocity

Encyclopedia of Healthcare Information Systems ◽

10.4018/978-1-59904-889-5.ch038 ◽

2008 ◽

pp. 281-289

Author(s):

Valentina Magagnin ◽

Maurizio Turiel ◽

Sergio Cerutti ◽

Luigi Delfino ◽

Enrico Caiani

Keyword(s):

Blood Flow ◽

Coronary Artery ◽

Flow Velocity ◽

Coronary Blood Flow ◽

Doppler Echocardiography ◽

Coronary Flow ◽

Connective Tissue Diseases ◽

Doppler Flow ◽

Intracoronary Doppler ◽

Artery Disease

The coronary flow reserve (CFR) represents an important functional parameter to assess epicardial coronary stenosis and to evaluate the integrity of coronary microcirculation (Kern, 2000; Sadamatsu, Tashiro, Maehira, & Yamamoto, 2000). CFR can be measured, during adenosine or dipyridamole infusion, as the ratio of maximal (pharmacologically stimulated) to baseline (resting) diastolic coronary blood flow peak. Even in absence of stenosis in epicardial coronary artery, the CFR may be decreased when coronary microvascular circulation is compromised by arterial hypertension with or without left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, syndrome X, hypertrophic cardiomyopathy, and connective tissue diseases (Dimitrow, 2003; Strauer, Motz, Vogt, & Schwartzkopff, 1997). Several methods have been established for measuring CFR: invasive (intracoronary Doppler flow wire) (Caiati, Montaldo, Zedda, Bina, & Iliceto, 1999b; Lethen, Tries, Brechtken, Kersting, & Lambertz, 2003a; Lethen, Tries, Kersting, & Lambertz, 2003b), semi-invasive and scarcely feasible (transesophageal Doppler echocardiography) (Hirabayashi, Morita, Mizushige, Yamada, Ohmori, & Tanimoto, 1991; Iliceto, Marangelli, Memmola, & Rizzon, 1991; Lethen, Tries, Michel, & Lambertz, 2002; Redberg, Sobol, Chou, Malloy, Kumar, & Botvinick, 1995), or extremely expensive and scarcely available methods (PET, SPECT, MRI) (Caiati, Cioglia, Montaldo, Zedda, Rubini, & Pirisi, 1999a; Daimon, Watanabe, Yamagishi, Muro, Akioka, & Hirata, 2001; Koskenvuo, Saraste, Niemi, Knuuti, Sakuma, & Toikka, 2003; Laubenbacher, Rothley, Sitomer, Beanlands, Sawada, & Sutor, 1993; Picano, Parodi, Lattanzi, Sambuceti, Andrade, & Marzullo, 1994; Saraste, Koskenvuo, Knuuti, Toikka, Laine, & Niemi, 2001; Williams, Mullani, Jansen, & Anderson, 1994), thus their clinical use is limited (Dimitrow, 2003). In addition, PET and intracoronary Doppler flow wire involve radiation exposure, with inherent risk, environmental impact, and biohazard connected with use of ionizing testing (Picano, 2003a). In the last decade, the development of new ultrasound equipments and probes has made possible the noninvasive evaluation of coronary blood velocity by Doppler echocardiography, using a transthoracic approach. In this way, the peak diastolic coronary flow velocity reserve (CFVR) can be estimated as the ratio of the maximal (pharmacologically stimulated) to baseline (resting) diastolic coronary blood flow velocity peak measured from the Doppler tracings. Several studies have shown that peak diastolic CFVR, computed in the distal portion of the left anterior descending (LAD) coronary artery, correlates with CFR obtained by more invasive techniques. This provided a reliable and non invasive tool for the diagnosis of LAD coronary artery disease (Caiati et al., 1999b; Caiati, Montaldo, Zedda, Montisci, Ruscazio, & Lai, 1999c; Hozumi, Yoshida, Akasaka, Asami, Ogata, & Takagi, 1998; Koskenvuo et al., 2003; Saraste et al., 2001).

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300.20 Non-invasive Quantification of Disturbed Coronary Blood Flow Using Pressure Drop and Vorticity

JACC Cardiovascular Interventions ◽

10.1016/j.jcin.2019.01.124 ◽

2019 ◽

Vol 12 (4) ◽

pp. S34

Author(s):

Kranthi K. Kolli ◽

Amir Ali Amiri Moghadam ◽

Seyedhamidreza Alaie ◽

Eva Romito ◽

Alexandre Caprio ◽

...

Keyword(s):

Blood Flow ◽

Pressure Drop ◽

Coronary Blood Flow ◽

Non Invasive

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Role of site of microsphere injection and catheter position on systemic and regional hemodynamics in rat

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1984.247.1.h35 ◽

1984 ◽

Vol 247 (1) ◽

pp. H35-H39 ◽

Cited By ~ 1

Author(s):

I. Kobrin ◽

M. B. Kardon ◽

W. Oigman ◽

B. L. Pegram ◽

E. D. Frohlich

Keyword(s):

Blood Flow ◽

Coronary Blood Flow ◽

Coronary Flow ◽

Left Ventricular ◽

Ventricular Catheter ◽

Catheter Position ◽

Flow Measurements ◽

Conscious Rats ◽

Anesthetized Rats ◽

Regional Hemodynamics

The influences of the site of microsphere injection (intra-atrial vs. intraventricular) and positioning of the left ventricular catheter (aortoventricular vs. atrioventricular) on systemic, renal, and coronary hemodynamics were evaluated in anesthetized rats. The effect of anesthesia on aortoventricular catheter positioning was also evaluated. In anesthetized and open-chest preparations, the systemic and renal hemodynamics were not affected by catheter position or site of microsphere injection; however, myocardial blood flow was dependent on these variables. Variations in coronary blood flow were significantly greater when the catheter was in the aortoventricular position (34 +/- 3%) than with an atrioventricular catheter (11 +/- 2%, P less than 0.01), irrespective of whether the microspheres were injected into the atrium or ventricle. Comparison of anesthetized and conscious rats with aortoventricular catheter indicated lesser variability in coronary blood flow in the conscious rats (P less than 0.01). Therefore, the greater variability of coronary flow measurements in anesthetized rats was caused by the position of the cardiac catheter in the aortoventricular route. However, the variability caused by the aortoventricular catheter was much less in conscious rats. Therefore, coronary flow hemodynamic measurements (microsphere technique) are less variable when they are made in conscious rats.

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Myocardial blood flow and coronary reserve in chronically anemic fetal lambs

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1999.277.1.r306 ◽

1999 ◽

Vol 277 (1) ◽

pp. R306-R313 ◽

Cited By ~ 8

Author(s):

Lowell E. Davis ◽

A. Roger Hohimer ◽

Mark J. Morton

Keyword(s):

Blood Flow ◽

Myocardial Blood Flow ◽

Coronary Blood Flow ◽

Coronary Flow ◽

Adenosine Infusion ◽

Fetal Sheep ◽

Coronary Reserve ◽

Flow Reserve ◽

Coronary Conductance ◽

The Difference

Chronic fetal anemia produces large compensatory increases in coronary blood flow in the near-term fetal lamb. To determine if increased coronary flow in anemic fetuses is associated with decreased coronary flow reserve or, alternatively, an increase in coronary conductance, we measured maximal coronary artery conductance during adenosine infusion before and during anemia. Isovolemic hemorrhage over 7 days reduced hematocrit from 30.6 ± 2.7 to 15.8 ± 2.4% ( P < 0.02) and the oxygen content from 7.3 ± 1.4 to 2.6 ± 0.4 ml/dl ( P < 0.001). Coronary blood flow increased from control (202 ± 60) to 664 ± 208 ml ⋅ min−1 ⋅ 100 g−1 with adenosine to 726 ± 169 ml ⋅ min−1 ⋅ 100 g−1 during anemia and to 1,162 ± 250 ml ⋅ min−1 ⋅ 100 g−1 (left ventricle) during anemia with adenosine infusion (all P< 0.001). Coronary conductance, determined during maximal vasodilation, was 18.2 ± 7.7 before and 32.8 ± 11.9 ml ⋅ min−1 ⋅ 100 g−1 ⋅ mmHg−1during anemia ( P < 0.001). Coronary reserve, the difference between resting and maximal myocardial blood flow interpolated at 40 mmHg, was unchanged in control and anemic fetuses (368 ± 142 and 372 ± 201 ml/min). Because hematocrit affects viscosity, anemic fetuses were transfused with blood to acutely increase the hematocrit back to control, and conductance was remeasured. Coronary blood flow decreased 57.3 ± 18.9% but was still 42.6 ± 18.9% greater than control. We conclude that in chronically anemic fetal sheep coronary conductance is increased and coronary reserve is maintained, and this is attributed in part to angiogenesis as well as changes in viscosity.

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A Case of an Obstructive Intramural Haematoma during Percutaneous Coronary Intervention Successfully Treated with Intima Microfenestrations Utilising a Cutting Balloon Inflation Technique

Case Reports in Cardiology ◽

10.1155/2018/4875041 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5

Author(s):

Osama Alsanjari ◽

Aung Myat ◽

James Cockburn ◽

Grigoris V. Karamasis ◽

David Hildick-Smith ◽

...

Keyword(s):

Blood Flow ◽

Coronary Blood Flow ◽

Coronary Intervention ◽

Intramural Haematoma ◽

Balloon Inflation ◽

Cutting Balloon ◽

Stent Deployment ◽

Stent Expansion ◽

Percutaneous Coronary

During percutaneous coronary interventions (PCI), good lesion preparation with adequate balloon predilatation is a fundamental step before stent deployment in order to achieve optimal stent expansion and favourable long-term outcomes post PCI. During PCI, inadvertent vessel tearing can occur, resulting in coronary dissections and formation of intramural haematomas. The latter might be associated with compression of the vessel lumen and significant compromise of the coronary blood flow leading to myocardial ischaemia and infarction. Herein, we present a case of intramural haematoma that occurred after PCI of the left anterior descending artery resulting in occlusion of the vessel and the subsequent use of a cutting balloon inflation technique to resolve the haematoma and restore the normal coronary blood flow.

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