Determinants of coronary blood flow in humans: quantification by intracoronary Doppler and ultrasound

2005 ◽  
Vol 98 (3) ◽  
pp. 1076-1082 ◽  
Author(s):  
Heinrich Wieneke ◽  
Clemens von Birgelen ◽  
Michael Haude ◽  
Holger Eggebrecht ◽  
Stefan Möhlenkamp ◽  
...  

The direct determinants of coronary flow are lumen area and blood flow velocity; however, the precise mechanisms that control these factors are not fully understood. The aim of the present study was to assess by which mechanisms lumen area and coronary flow velocity interact with hemodynamic and morphometric factors, thereby influencing coronary flow. Intracoronary Doppler and ultrasound measurements were performed in 28 patients without coronary lumen irregularities. Flow velocity and lumen cross-sectional area were measured in the proximal segments of all three coronary arteries. Global lumen cross-sectional area and global flow were obtained by adding up the values of all three coronary arteries. Left ventricular mass was assessed by echocardiography. Stress-mass-heart rate and pressure-rate products reflecting myocardial oxygen demand were calculated. Global coronary flow increased during adenosine-induced hyperemia from 197 ± 72 to 637 ± 204 ml/min ( P < 0.001). Global coronary flow closely correlated with the stress-mass-heart rate product ( r = 0.62; P < 0.001). Looking at the two constituents of flow separately, global coronary cross-sectional area was closely related to left ventricular muscle mass ( r = 0.61; P < 0.001), whereas mean coronary flow velocity at rest showed a strong linear relation with the pressure-rate product ( r = 0.64; P < 0.001). There was no interaction between cross-sectional area and blood flow velocity in any of the coronary vessels. Coronary lumen size and flow velocity, the two determinants of coronary flow, are principally determined by different physiological factors. Long-term flow adaptation is achieved by an increase in coronary lumen size, whereas short-term myocardial oxygen requirements are met by changes in resting flow velocity.

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.


Heart ◽  
2020 ◽  
Vol 106 (15) ◽  
pp. 1176-1182
Author(s):  
Timothy C Tan ◽  
Maria Carmo Pereira Nunes ◽  
Mark Handschumacher ◽  
Octavio Pontes-Neto ◽  
Yong-Hyun Park ◽  
...  

ObjectiveCardioembolic (CE) stroke carries significant morbidity and mortality. Left atrial (LA) size has been associated with CE risk. We hypothesised that differential LA remodelling impacts on pathophysiological mechanism of major CE strokes.MethodsA cohort of consecutive patients hospitalised with ischaemic stroke, classified into CE versus non-CE strokes using the Causative Classification System for Ischaemic Stroke were enrolled. LA shape and remodelling was characterised by assessing differences in maximal LA cross-sectional area (LA-CSA) in a cohort of 40 prospectively recruited patients with ischaemic stroke using three-dimensional (3D) echocardiography. Flow velocity profiles were measured in spherical versus ellipsoidal in vitro models to determine if LA shape influences flow dynamics. Two-dimensional (2D) LA-CSA was subsequently derived from standard echocardiographic views and compared with 3D LA-CSA.ResultsA total of 1023 patients with ischaemic stroke were included, 230 (22.5%) of them were classified as major CE. The mean age was 68±16 years, and 464 (45%) were women. The 2D calculated LA-CSA correlated strongly with the LA-CSA measured by 3D in both end-systole and end-diastole. In vitro flow models showed shape-related differences in mid-level flow velocity profiles. Increased LA-CSA was associated with major CE stroke (adjusted relative risk 1.10, 95% CI 1.04 to 1.16; p<0.001), independent of age, gender, atrial fibrillation, left ventricular ejection fraction and CHA2DS2-VASc score. Specifically, the inclusion of LA-CSA in a model with traditional risk factors for CE stroke resulted in significant improvement in model performance with the net reclassification improvement of 0.346 (95% CI 0.189 to 0.501; p=0.00001) and the integrated discrimination improvement of 0.013 (95% CI 0.003 to 0.024; p=0.0119).ConclusionsLA-CSA is a marker of adverse LA shape associated with CE stroke, reflecting importance of differential LA remodelling, not simply LA size, in the mechanism of CE risk.


2018 ◽  
Vol 26 (4) ◽  
pp. 186 ◽  
Author(s):  
EthanC Hill ◽  
TerryJ Housh ◽  
CoryM Smith ◽  
JoshuaL Keller ◽  
RichardJ Schmidt ◽  
...  

2005 ◽  
Vol 61 (2) ◽  
Author(s):  
M. A. Gregory ◽  
M. N. Deane ◽  
M. Marsh

Objective: The precise mechanisms by which massage promotes repair in injured soft tissue are unknown. Various authorshave attributed the beneficial effects of massage to vasodilation and increased skin and muscle blood flow. The aim of this study was to determine whether deep transverse friction massage (DTF) causes capillary vasodilation in untraumatised skeletal muscle. Setting: Academic institution.Interventions: Twelve New Zealand white rabbits were anaesthetised and the left biceps femoris muscle received 10 minutes of DTF. Following treatment, wedge biopsies were taken from the musclewithin 10 minutes of treatment (R1 - 4), 24 hours (R5 - 8) and 6 days(R9 - 12) after treatment. To serve as controls, similar biopsies weretaken from the right biceps femoris of animals. The samples were fixed, dehydrated and embedded in epoxy resin.Transverse sections (1µm) of muscle were cut, stained with 1% aqueous alkaline toluidine blue and examined with a light microscope using a 40X objective. Images containing capillaries were captured using an image analyser with SIS software and the cross sectional diameters of at least 60 capillaries were measured from each specimen. Main Outcome Measures: Changes in capillary diameter. Results: The mean capillary diameters in control muscle averaged 4.76 µm. DTF caused a significant immediate increase of 17.3% in cross sectional area (p<0.001), which was not significantly increased by 10.0% after 24 hours (p>0.05). Six days after treatment the cross-sectional area of the treated muscle was 7.6% smaller than the controls. Conclusions: This confirms the contention that DTF stimulates muscle blood flow immediately after treatment and this may account for its beneficial effects in certain conditions. 


2017 ◽  
Vol 16 (3) ◽  
pp. 214-219 ◽  
Author(s):  
Marta Gimunová ◽  
Martin Zvonař ◽  
Kateřina Kolářová ◽  
Zdeněk Janík ◽  
Ondřej Mikeska ◽  
...  

Abstract Background During pregnancy, a number of changes affecting venous blood flow occur in the circulatory system, such as reduced vein wall tension or increased exposure to collagen fibers. These factors may cause blood stagnation, swelling of the legs, or endothelial damage and consequently lead to development of venous disease. Objectives The aim of this study is to evaluate the effect of special footwear designed to improve blood circulation in the feet on venous blood flow changes observed during advancing phases of pregnancy. Methods Thirty healthy pregnant women participated in this study at 25, 30, and 35 weeks of gestation. Participants were allocated at random to an experimental group (n = 15) which was provided with the special footwear, or a control group (n = 15). At each data collection session, Doppler measurements of peak systolic blood flow velocity and cross-sectional area of the right popliteal vein were performed using a MySonoU6 ultrasound machine with a linear transducer (Samsung Medison). The differences were compared using Cohen’s d test to calculate effect size. Results With advancing phases of pregnancy, peak systolic velocity in the popliteal vein decreased significantly in the control group, whereas it increased significantly in the experimental group. No significant change in cross-sectional area was observed in any of the groups. Conclusions Findings in the experimental group demonstrated that wearing the footwear tested may prevent venous blood velocity from reducing during advanced phases of pregnancy. Nevertheless, there is a need for further investigation of the beneficial effect on venous flow of the footwear tested and its application.


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

2018 ◽  
Vol 31 ◽  
pp. 03001 ◽  
Author(s):  
Iskahar ◽  
Suripin ◽  
Isdiyana

Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of water level in the reservoir storage, so the solution can be found to remove / reduce sediment before entering the reservoir. The method used is the experimental, by making the physical model of the river estuary leading to the reservoir. This study expects a solution to reduce sedimentation, so that sedimentation can be removed / minimized before entering the reservoir. This research tries to apply bypass channel to reduce the sedimentation at the river estuary. Bypass channels can be applied to overcome sedimentation at the river estuary, but in order for the sediment to be removed optimally, it is necessary to modify the mouth of bypass channel and channel angle.


Author(s):  
Valentina Magagnin ◽  
Maurizio Turiel ◽  
Sergio Cerutti ◽  
Luigi Delfino ◽  
Enrico Caiani

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).


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
C Daros ◽  
L Cortigiani ◽  
Q Ciampi ◽  
N Gaibazzi ◽  
A Zagatina ◽  
...  

Abstract Background Coronary microvascular disease has been described in heart failure (HF) in presence of angiographically normal epicardial coronary arteries. The prevalence of a reduction of coronary flow velocity reserve (CFVR) in different types of HF and its link with left ventricular contractile reserve (LVCR) is unclear. Aim To assess CFVR and LVCR in HF. Methods In a prospective, observational, multicenter study, we recruited 380 patients (234 male, 61%, age 66±11 years): 143 (38%) with HF and reduced (<40%) ejection fraction (HFrEF); 98 (26%) with HF and mid-range (40–50%) ejection fraction (HFmrEF); 139 (36%) patients with HF and preserved (>50%) ejection fraction (HFpEF). A control group of 52 asymptomatic patients (23 male, 44%, age 61±14 years) referred to testing for screening was also selected (Controls). All patients underwent dipyridamole (0.84 mg/kg) stress echocardiography in 12 accredited laboratories of 3 countries (Argentina, Brazil and Italy). CFVR was calculated as the stress/rest ratio of diastolic peak flow velocity pulsed-Doppler assessment of left anterior descending (LAD) artery flow. We assessed left ventricular contractile reserve (LVCR) based on global LV Force (systolic blood pressure/end-systolic volume). Results Reduced (≤2.0) CFVR was observed in 0/52 controls (0%); 25/139 HFpEF (18%); 28/98 HFmrEF (29%); 78/143 HFrEF (54%, p<0.001 vs all other groups). CFVR was highest in controls (2.80±0.57), lower in HFpEF (2.51±0.57) and HFmrEF (2.26±0.44), lowest in HFrEF (2.04±0.48, p<0.001 vs all other groups). The correlation with LVCR was absent in controls (r=0.098, p=0.491) and HFmrEF (r=0.032, p=0.756), present in HFrEF (r=0.375, p<0.001) and HFpEF (r=0.314, p<0.001). LVCR vs CFVR Conclusions CFVR is frequently abnormal in all types of HF, although more frequently and more profoundly in HFrEF. CFVR mirrors contractile reserve in HFrEF and - less tightly - in HFpEF.


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