scholarly journals Stability of Flow Velocity and Intracoronary Resistance in the Intracoronary Electrocardiogram-triggered Pressure Ratio

2021 ◽  
Author(s):  
Masafumi Nakayama ◽  
Nobuhiro Tanaka ◽  
Takashi Uchiyama ◽  
Takaaki Ohkawauchi ◽  
Yusuke Tsuboko ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Coronary Flow ◽  
Pressure Ratio ◽  
Aortic Pressure ◽  
Fractional Flow ◽  
Instantaneous Flow ◽  
Flow Reserve ◽  
Value Flow ◽  
Index Value ◽  
T Values

Abstract It has been found that the assessment of coronary artery lesions using the fractional flow reserve and instantaneous flow reserve measurements reduces the incidence of further cardiovascular events. Here, we investigated differences in the coronary flow velocity and resistance within the analysis interval between the instantaneous flow reserve (iFR) and the intracoronary electrocardiogram (IC-ECG)-triggered distal/aortic pressure (Pd/Pa) ratio (ICE-T). Thirty-three consecutive patients with stenoses that required coronary flow measurement were enrolled. ICE-T was defined as the average Pd/Pa ratio in the period corresponding to the isoelectric line of the IC-ECG. The index value, flow velocity, and intracoronary resistance during the analysis intervals of the iFR and ICE-T, both at rest and under hyperemia, were compared. The index value and intracoronary resistance of the ICE-T were found to be significantly lower, while the flow velocity was significantly higher, than those of the iFR (P < 0.001), and all fluctuations in ICE-T values were also significantly smaller than those in the iFR.In conclusion, the ICE-T is theoretically superior to pressure-dependent indices for analyzing phases with low and stable resistance, without an increase in invasiveness.

scholarly journals The stability of flow velocity and intracoronary resistance in the intracoronary electrocardiogram-triggered pressure ratio

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masafumi Nakayama ◽  
Nobuhiro Tanaka ◽  
Takashi Uchiyama ◽  
Takaaki Ohkawauchi ◽  
Yusuke Tsuboko ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Coronary Flow ◽  
Pressure Ratio ◽  
Aortic Pressure ◽  
Fractional Flow ◽  
Flow Measurements ◽  
Flow Reserve ◽  
The Stability ◽  
Index Value ◽  
T Values

AbstractAssessment of coronary artery lesions using the fractional flow reserve and instantaneous flow reserve (iFR) measurements has been found to reduce the incidence of further cardiovascular events. Here, we investigated differences in terms of coronary flow velocity and resistance within the analysis interval between the iFR and the intracoronary electrocardiogram (IC-ECG)-triggered distal/aortic pressure (Pd/Pa) ratio (ICE-T). We enrolled 23 consecutive patients (n = 33 stenoses) who required coronary flow measurements. ICE-T was defined as the average Pd/Pa ratio in the period corresponding to the isoelectric line of the IC-ECG. We compared the index value, flow velocity, and intracoronary resistance during the analysis intervals of the iFR and the ICE-T, both at rest and under hyperemia. ICE-T values and ICE-T intracoronary resistance were both found to be significantly lower, whereas flow velocity was significantly higher than those of the iFR at both rest and under hyperemia (P < 0.001), and all fluctuations in ICE-T values were also significantly smaller than those in the iFR. In conclusion, the ICE-T appears theoretically superior to pressure-dependent indices for analyzing phases with low and stable resistance, without an increase in invasiveness.

Abstract 14743: Usefulness of Estimated Coronary Flow Velocity Using Quantitative Flow Ratio for Intermediate Coronary Stenosis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Eiji Ichimoto ◽  
Nao Konagai ◽  
Sawako Horie ◽  
Atsushi Hasegawa ◽  
Hirofumi Miyahara ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Coronary Stenosis ◽  
Coronary Flow ◽  
Flow Ratio ◽  
Operating Characteristics ◽  
Fractional Flow ◽  
Coronary Flow Velocity ◽  
Flow Reserve ◽  
Quantitative Flow Ratio ◽  
Quantitative Flow

Introduction: Quantitative flow ratio (QFR) is a diagnostic modality for functional assessment for intermediate coronary stenosis without the use of pressure wire. QFR is calculated from 3-dimensional quantitative CAG (3D-QCA) using an advanced algorithm that enables fast computation of the pressure drop caused by coronary stenosis. Hypothesis: We assessed the usefulness of QFR and the association with an estimated coronary flow velocity (eCFV) for intermediate coronary stenosis. Methods: A total of 100 lesions in 80 consecutive patients were assessed Fractional Flow Reserve (FFR) for intermediate coronary stenosis between January 2011 and April 2019. Of these, 97 lesions in 77 patients who underwent QFR were included in this study. Patients were classified into two groups (FFR ≤ 0.80 or FFR > 0.80). QFR and eCFV using contrast were measured by Thrombolysis in Myocardial Infarction (TIMI) frame counts. Results: There was no significant differences in target vessels (p = 0.90) and diffuse lesions (p = 0.06) between the two groups (FFR ≤ 0.80 or FFR > 0.80). Mean FFR and QFR values were 0.78 ± 0.12 and 0.77 ± 0.11, respectively. QFR had a good correlation with FFR values (r = 0.86, p < 0.0001). The diagnostic accuracy, sensitivity, and specificity on QFR ≤ 0.80 were 91.8%, 92.7% and 90.5%, respectively. The eCFV of FFR ≤ 0.80 was greater than that of FFR > 0.80 (0.19 ± 0.08 m/s vs. 0.14 ± 0.06 m/s, p<0.001). Figure showed that the eCFV correlated with FFR values (r = -0.29, p < 0.01). Moreover, the eCFV had a high area under the curve (AUC = 0.71, p < 0.01) on Receiver operating characteristics curve (ROC) analysis with FFR ≤ 0.80. Conclusions: QFR was useful for the assessment of functional stenosis severity. As eCFV was faster, FFR was lower for intermediate coronary stenosis. The eCFV had a good correlation with FFR and may become one of the evaluations for ischemia.

Abstract 19177: Loss of Coronary Perfusion Efficiency in Microvascular Disease

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Matthew Lumley ◽  
Matthew Ryan ◽  
Kaleab Asrress ◽  
Rupert Williams ◽  
Satpal Ari ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Coronary Flow ◽  
Microvascular Disease ◽  
Rate Pressure Product ◽  
Coronary Perfusion ◽  
Cardiac Events ◽  
Fractional Flow ◽  
Wave Separation ◽  
Flow Reserve ◽  
Response To Stress

Introduction: Coronary Microvascular Disease (MVD) is associated with an unfavorable prognosis, even in the absence of significant epicardial disease. The pathophysiological basis of increased cardiac events is unclear. The aim of this study was to characterize the forces that govern myocardial perfusion at rest and during stress. Methods: Patients with chest pain syndromes requiring Fractional Flow Reserve (FFR) assessment were screened and those with a FFR>0.80 were included. MVD was defined by coronary flow reserve (CFR) < 2.0. Controls were those with CFR>2.0. Simultaneous intracoronary pressure (P d ) and flow velocity (U) recordings were made at rest and hyperemia. Microvascular Resistance (MR)= P d /U. Wave intensity = dP d /dt x dU/dt and wave separation analysis was used to identify the waves that accelerate and decelerate flow. The proportional contribution of accelerating waves was assessed as an index of coronary perfusion efficiency. Results: 39 consecutive patients were enrolled, 21 had MVD and 18 comprised controls. The groups were matched for atherosclerotic risk factors, rate-pressure-product and P d . Coronary flow velocity in MVD patients was higher at rest (21.5±6.4 vs. 14.1±4.5cms -1 , p < 0.001) but lower during hyperemia (28.3±13.0 vs. 45.1±13.1cms -1 , p < 0.001) compared to controls. While resting MR was lower in MVD (501±162 vs. 755±262 mmHg.cm -1 .s, p = 0.001), hyperemic MR was significantly lower in controls. At rest the magnitude of the accelerating waves was higher in the MVD group than controls. The percentage contribution of accelerating waves increased with hyperemia in controls but decreased in MVD patients (figure). Conclusion: MVD manifests as resting microvascular dilation as well as diminished response to stress. While the normal heart has improved efficiency during hyperemia, in MVD efficiency decreases and as a result, flow augmentation is attenuated. These processes render the myocardium more susceptible to ischemia.

Combining Baseline Distal-to-Aortic Pressure Ratio and Fractional Flow Reserve in the Assessment of Coronary Stenosis Severity

2015 ◽  
Vol 8 (13) ◽  
pp. 1681-1691 ◽  
Author(s):  
Mauro Echavarría-Pinto ◽  
Tim P. van de Hoef ◽  
Martijn A. van Lavieren ◽  
Sukhjinder Nijjer ◽  
Borja Ibañez ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Pressure Ratio ◽  
Aortic Pressure ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Stenosis Severity

scholarly journals TCT-300 Combining baseline distal-to-aortic pressure ratio and fractional flow reserve in the assessment of coronary stenosis severity

2015 ◽  
Vol 66 (15) ◽  
pp. B119
Author(s):  
Mauro Echavarria-Pinto ◽  
Tim P. van de Hoef ◽  
Martijn A. van Lavieren ◽  
Sukhjinder S. Nijjer ◽  
Borja Ibañez ◽  
...  
Keyword(s):  
Fractional Flow Reserve ◽  
Coronary Stenosis ◽  
Pressure Ratio ◽  
Aortic Pressure ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Stenosis Severity

scholarly journals Temporal dissociation between the minimal distal-to-aortic pressure ratio and peak hyperemia during intravenous adenosine infusion

2017 ◽  
Vol 312 (5) ◽  
pp. H992-H1001 ◽  
Author(s):  
Lorena Casadonte ◽  
Koen M. Marques ◽  
Jos A. E. Spaan ◽  
Maria Siebes
Keyword(s):  
Flow Velocity ◽  
Coronary Flow ◽  
Fluid Dynamic ◽  
Pressure Ratio ◽  
Aortic Pressure ◽  
Adenosine Infusion ◽  
Maximal Velocity ◽  
Systemic Hemodynamic ◽  
Stenosis Severity ◽  
Adenosine Administration

The present study sought to compare the temporal relation between maximal coronary flow (peak hyperemia) and minimal coronary-to-aortic pressure ratio (Pd/Pa) for intracoronary (IC) and intravenous (IV) adenosine administration. Peak hyperemia is assumed to coincide with the minimal Pd/Pa value. However, this has not been confirmed for systemic hemodynamic variations during IV adenosine infusion. Hemodynamic responses to IV and IC adenosine administration were obtained in 12 patients (14 lesions) using combined IC pressure and flow velocity measurements. A fluid dynamic model was used to predict the change in Pd/Pa for different stenosis severities and varying Pa. Hemodynamic variability during IV adenosine hyperemia was greater than during IC adenosine, as assessed by the coefficient of variation. During IV adenosine, flow velocity peaked 28 ± 4 (SE) s after the onset of hyperemia, while Pd/Pa reached a minimum (0.82 ± 0.01) 22 ± 7 s later ( P < 0.05), when Pa had declined by 6.1% and hyperemic velocity by 4.5% ( P < 0.01). Model outcomes corroborated the role of variable Pa in this dissociation. In contrast, maximal flow and minimal Pd/Pa coincided for IC adenosine, with IV-equivalent peak velocities and a higher Pd/Pa ratio (0.86 ± 0.01, P < 0.01). Hemodynamic variability during continuous IV adenosine infusion can lead to temporal dissociation of minimal Pd/Pa and peak hyperemia, in contrast to IC adenosine injection, where maximal velocity and minimal Pd/Pa coincide. Despite this variability, stenosis hemodynamics remained stable with both ways of adenosine administration. Our findings suggest advantages of IC over IV adenosine to identify maximal hyperemia from pressure-only measurements. NEW & NOTEWORTHY Systemic hemodynamic variability during intravenous adenosine infusion produces substantial temporal dissociation between peak hyperemia appraised by coronary flow velocity and the minimal distal-to-aortic pressure ratio commonly used to determine functional stenosis severity. This dissociation was absent for intracoronary adenosine administration and tended to be mitigated in patients receiving Ca2+ antagonists.

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