scholarly journals Impact of Hydrostatic Pressure Variations Caused by Height Differences in Supine and Prone Positions on Fractional Flow Reserve Values in the Coronary Circulation

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Yoshitaka Kawaguchi ◽  
Kazuki Ito ◽  
Humihiko Kin ◽  
Yusuke Shirai ◽  
Ayako Okazaki ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Prone Position ◽  
Fractional Flow Reserve ◽  
Aortic Pressure ◽  
Fractional Flow ◽  
Circumflex Artery ◽  
Left Circumflex Artery ◽  
Flow Reserve ◽  
Catheter Tip

Objectives. To examine the influence of hydrostatic pressure on fractional flow reserve (FFR) in vivo.Background. Systematic differences in FFR values have been observed previously in the left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). It has been suggested that as the hydrostatic pressure variations caused by the height differences between the catheter tip (mean aortic pressure (Pa)) and pressure-wire sensor (mean distal intracoronary pressure (Pd)) are small, intracoronary pressure need not be corrected.Methods. Resting Pd/Pa and FFR values in 23 patients (27 lesions) were measured and compared in supine and prone positions. These values were corrected by hydrostatic pressure influenced by height levels and compared. Height differences between Pa and Pd were calculated using coronary computed tomography angiographies.Results. In LAD, resting Pd/Pa and FFR values were significantly higher in the prone position than in the supine position (0.97 ± 0.05 vs 0.89 ± 0.04,P<0.001(resting Pd/Pa); 0.81 ± 0.09 vs 0.72 ± 0.07,P<0.001(FFR)). Conversely, in LCX and RCA, these values were significantly lower in the prone position (LCX: 0.93 ± 0.03 vs 0.98 ± 0.03,P<0.001(resting Pd/Pa); 0.84 ± 0.05 vs 0.89 ± 0.04,P<0.001(FFR); RCA: 0.91 ± 0.04 vs 0.98 ± 0.03,P=0.005(resting Pd/Pa); 0.78 ± 0.07 vs 0.84 ± 0.07,P=0.019(FFR)). FFR values corrected by hydrostatic pressure showed good correlations in the supine and prone positions (R2 = 0.948 in LAD;R2 = 0.942 in LCX;R2 = 0.928 in RCA).Conclusions. Hydrostatic pressure variations due to height levels influence intracoronary pressure measurements and largely affect resting Pd/Pa and FFR, which might have caused systematic differences in FFR values between the anterior and posterior coronary territories.

scholarly journals Impact of hydrostatic pressure on fractional flow reserve: in vivo experimental study of anatomical height difference of coronary arteries

2020 ◽  
Vol 76 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Suguru Nagamatsu ◽  
Kenji Sakamoto ◽  
Takayoshi Yamashita ◽  
Ryota Sato ◽  
Noriaki Tabata ◽  
...  
Keyword(s):  
Experimental Study ◽  
Hydrostatic Pressure ◽  
Coronary Arteries ◽  
Fractional Flow Reserve ◽  
Fractional Flow ◽  
Height Difference ◽  
Flow Reserve

Fractional flow reserve

2021 ◽  
pp. 63-67
Author(s):  
Giovanni Ciccarelli ◽  
Emanuele Barbato ◽  
Bernard De Bruyne
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Coronary Intervention ◽  
Aortic Pressure ◽  
Fractional Flow ◽  
Coronary Pressure ◽  
Flow Reserve ◽  
Percutaneous Coronary

Fractional flow reserve is an index of the physiological significance of a coronary stenosis, defined as the ratio of maximal myocardial blood flow in the presence of the stenosis to the theoretically normal maximal myocardial blood flow (i.e. in the absence of the stenosis). This flow ratio can be calculated from the ratio of distal coronary pressure to central aortic pressure during maximal hyperaemia. More practically, fractional flow reserve indicates to what extent the epicardial segment can be responsible for myocardial ischaemia and, accordingly, fractional flow reserve quantifies the expected perfusion benefit from revascularization by percutaneous coronary intervention. Very limited evidence exists on the role on fractional flow reserve for bypass grafts.

scholarly journals A validated predictive model of coronary fractional flow reserve

2011 ◽  
Vol 9 (71) ◽  
pp. 1325-1338 ◽  
Author(s):  
Yunlong Huo ◽  
Mark Svendsen ◽  
Jenny Susana Choy ◽  
Z.-D. Zhang ◽  
Ghassan S. Kassab
Keyword(s):  
Analytical Model ◽  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Coronary Flow ◽  
Energy Losses ◽  
Fractional Flow ◽  
Conservation Of Energy ◽  
Flow Reserve

Myocardial fractional flow reserve (FFR), an important index of coronary stenosis, is measured by a pressure sensor guidewire. The determination of FFR, only based on the dimensions (lumen diameters and length) of stenosis and hyperaemic coronary flow with no other ad hoc parameters, is currently not possible. We propose an analytical model derived from conservation of energy, which considers various energy losses along the length of a stenosis, i.e. convective and diffusive energy losses as well as energy loss due to sudden constriction and expansion in lumen area. In vitro (constrictions were created in isolated arteries using symmetric and asymmetric tubes as well as an inflatable occluder cuff) and in vivo (constrictions were induced in coronary arteries of eight swine by an occluder cuff) experiments were used to validate the proposed analytical model. The proposed model agreed well with the experimental measurements. A least-squares fit showed a linear relation as (Δ p or FFR) experiment = a (Δ p or FFR) theory + b , where a and b were 1.08 and −1.15 mmHg ( r 2 = 0.99) for in vitro Δ p , 0.96 and 1.79 mmHg ( r 2 = 0.75) for in vivo Δ p , and 0.85 and 0.1 ( r 2 = 0.7) for FFR. Flow pulsatility and stenosis shape (e.g. eccentricity, exit angle divergence, etc.) had a negligible effect on myocardial FFR, while the entrance effect in a coronary stenosis was found to contribute significantly to the pressure drop. We present a physics-based experimentally validated analytical model of coronary stenosis, which allows prediction of FFR based on stenosis dimensions and hyperaemic coronary flow with no empirical parameters.

scholarly journals In vivo validation of mathematically derived fractional flow reserve for assessing haemodynamics of coronary tandem lesions

2016 ◽  
Vol 12 (11) ◽  
pp. e1375-e1384 ◽  
Author(s):  
Jihoon Kweon ◽  
Young-Hak Kim ◽  
Dong Hyun Yang ◽  
June-Goo Lee ◽  
Jae-Hyung Roh ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Tandem Lesions ◽  
In Vivo Validation

Functional coronary assessment: fractional flow reserve

ESC CardioMed ◽  
2018 ◽  
pp. 640-643
Author(s):  
Emanuele Barbato ◽  
Fabio Mangiacapra
Keyword(s):  
Blood Flow ◽  
Fractional Flow Reserve ◽  
Coronary Revascularization ◽  
Threshold Value ◽  
Aortic Pressure ◽  
Multivessel Disease ◽  
Fractional Flow ◽  
Transcatheter Aortic Valve ◽  
Coronary Pressure ◽  
Flow Reserve

Fractional flow reserve (FFR) is the invasive standard of reference in identifying haemodynamically significant stenoses, those that are able to induce reversible myocardial ischaemia. Although defined as the ratio of maximum blood flow in a stenotic coronary to maximum blood flow if the same coronary would be normal, FFR is expressed as the ratio of two pressures: the distal coronary pressure measured by an intracoronary pressure guidewire and the proximal coronary or aortic pressure measured at the tip of the guiding catheter during maximal coronary hyperaemia. A threshold value of FFR less than or equal to 0.80 is currently recommended to indicate or defer coronary revascularization. In fact, a FFR-guided revascularization strategy has been shown to be safe and effective in reducing adverse events in a number of anatomical lesion subsets, including intermediate coronary stenoses, left main stenoses, multivessel disease, bifurcation lesions, sequential stenoses, stented vessels, and bypass grafts. There is growing interest in the use of FFR also in the setting of acute coronary syndrome. In patients with acute ST-elevation myocardial infarction, FFR has been adopted to assess intermediate stenoses incidentally found in non-culprit coronaries, and may be useful to guide the completeness of revascularization in the presence of multivessel disease. Finally, FFR is emerging as a novel potential area for invasive functional assessment of coronary atherosclerotic disease in patients with aortic stenosis, due to the increasing indications to transcatheter aortic valve implantation.

Sign in / Sign up

Export Citation Format

Share Document