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  • 1
    Online Resource
    Online Resource
    Effect of simultaneous intracoronary guidewires on the predictive accuracy of functional parameters of coronary lesion severity
    American Physiological Society ; 2007
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 292, No. 5 ( 2007-05), p. H2349-H2355
    Details
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 292, No. 5 ( 2007-05), p. H2349-H2355
    Abstract: The aim of this study was to assess the influence of a second guidewire on the diagnostic accuracy of functional parameters of coronary lesion severity. Sixty-five patients with intermediate coronary lesions underwent myocardial perfusion scintigraphy. Fractional flow reserve (FFR), coronary flow velocity reserve (CFVR), and hyperemic stenosis resistance (HSR) index (HSR = stenosis pressure gradient ÷ velocity) were determined in 77 lesions. Distal pressure and velocity were acquired simultaneously (dual wire) and sequentially (single wire) with two sensor-equipped guidewires. Overall, functional parameters deteriorated from single- to dual-wire assessment. In patients without ischemia, the good diagnostic performance of FFR, CFVR, and HSR deteriorated significantly ( P 〈 0.001) when assessed by dual wires, with an increase in the number of false-positive results. This trend was more pronounced for HSR, since the presence of a second wire reduced maximal velocity and increased the pressure gradient. The presence of two guidewires, especially across a myocardial perfusion scintigraphy-induced nonsignificant lesion, is associated with overestimation of the hemodynamically assessed lesion severity and, therefore, is likely to have a major impact on clinical decision making. This underscores the advantage of a dual-sensor-equipped guidewire for the evaluation of stenosis severity by combined pressure and velocity measurements.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    URL: Article
    DOI: 10.1152/ajpheart.01042.2006
    RVK:
    WA 15000
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2007
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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  • 2
    Online Resource
    Online Resource
    Increased diastolic time fraction as beneficial adjunct of α 1 -adrenergic receptor blockade after percutaneous coronary intervention
    American Physiological Society ; 2008
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 295, No. 5 ( 2008-11), p. H2054-H2060
    Details
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 295, No. 5 ( 2008-11), p. H2054-H2060
    Abstract: The effect of α 1 -receptor blockade with urapidil on coronary blood flow and left ventricular function has been attributed to relief of diffuse coronary vasoconstriction following percutaneous coronary intervention (PCI). We hypothesized that an increase in diastolic time fraction (DTF) contributes to the beneficial action of urapidil. In eleven patients with a 63% (SD 13) diameter stenosis, ECG, aortic pressure (P a ) and distal intracoronary pressure (P d ), and blood flow velocity were recorded at baseline and throughout adenosine-induced hyperemia. Measurements were obtained before and after PCI and after subsequent α 1 -receptor blockade with urapidil (10 mg ic). DTF was determined from the ECG and the P a waveform. Functional parameters such as coronary flow velocity reserve, fractional flow reserve, and an index of hyperemic microvascular resistance (HMR) were assessed. Urapidil administration after PCI induced an upward shift in the DTF-heart rate relationship, resulting in a 3.1% (SD 2.7) increase in hyperemic DTF at a constant heart rate ( P 〈 0.005) due to a shorter duration of systole. Hyperemic P a and P d decreased, respectively, by 6.1% (SD 6.6; P 〈 0.05) and 5.7% (SD 5.8; P 〈 0.01) after α 1 -blockade. Although epicardially measured functional parameters were on average not altered by α 1 -blockade due to concurrent changes in pressure and heart rate, HMR decreased by urapidil in those patients where coronary pressure remained constant. In conclusion, α 1 -receptor blockade after PCI produced a modest but significant prolongation of DTF at a given heart rate, thereby providing an adjunctive beneficial mechanism for improving subendocardial perfusion, which critically depends on DTF.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    URL: Article
    DOI: 10.1152/ajpheart.91400.2007
    RVK:
    WA 15000
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2008
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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  • 3
    Online Resource
    Online Resource
    Minimal effect of collateral flow on coronary microvascular resistance in the presence of intermediate and noncritical coronary stenoses
    American Physiological Society ; 2012
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 303, No. 4 ( 2012-08-15), p. H422-H428
    Details
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 303, No. 4 ( 2012-08-15), p. H422-H428
    Abstract: Depending on stenosis severity, collateral flow can be a confounding factor in the determination of coronary hyperemic microvascular resistance (HMR). Under certain assumptions, the calculation of HMR can be corrected for collateral flow by incorporating the wedge pressure (P w ) in the calculation. However, although P w 〉 25 mmHg is indicative of collateral flow, P w does in part also reflect myocardial wall stress neglected in the assumptions. Therefore, the aim of this study was to establish whether adjusting HMR by P w is pertinent for a diagnostically relevant range of stenosis severities as expressed by fractional flow reserve (FFR). Accordingly, intracoronary pressure and Doppler flow velocity were measured a total of 95 times in 29 patients distal to a coronary stenosis before and after stepwise percutaneous coronary intervention. HMR was calculated without (HMR) and with P w -based adjustment for collateral flow (HMR C ). FFR ranged from 0.3 to 1. HMR varied between 1 and 5 and HMR C between 0.5 and 4.2 mmHg·cm −1 ·s. HMR was about 37% higher than HMR C for stenoses with FFR 〈 0.6, but for FFR 〉 0.8, the relative difference was reduced to 4.4 ± 3.4%. In the diagnostically relevant range of FFR between 0.6 and 0.8, this difference was 16.5 ± 10.4%. In conclusion, P w -based adjustment likely overestimates the effect of potential collateral flow and is not needed for the assessment of coronary HMR in the presence of a flow-limiting stenosis characterized by FFR between 0.6 and 0.8 or for nonsignificant lesions.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    URL: Article
    DOI: 10.1152/ajpheart.00003.2012
    RVK:
    WA 15000
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2012
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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  • 4
    Online Resource
    Online Resource
    Coronary wave intensity during the Valsalva manoeuvre in humans reflects altered intramural vessel compression responsible for extravascular resistance
    Wiley ; 2012
    In:  The Journal of Physiology Vol. 590, No. 18 ( 2012-09), p. 4623-4635
    Details
    In: The Journal of Physiology, Wiley, Vol. 590, No. 18 ( 2012-09), p. 4623-4635
    Type of Medium: Online Resource
    ISSN: 0022-3751 , 1469-7793
    URL: Issue
    URL: Article
    DOI: 10.1113/tjp.2012.590.issue-18
    DOI: 10.1113/jphysiol.2012.229914
    RVK:
    WA 15000
    Language: English
    Publisher: Wiley
    Publication Date: 2012
    detail.hit.zdb_id: 1475290-6
    SSG: 12
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  • 5
    Online Resource
    Online Resource
    Myocardial infarction accelerates atherosclerosis
    Springer Science and Business Media LLC ; 2012
    In:  Nature Vol. 487, No. 7407 ( 2012-07-19), p. 325-329
    Details
    In: Nature, Springer Science and Business Media LLC, Vol. 487, No. 7407 ( 2012-07-19), p. 325-329
    Type of Medium: Online Resource
    ISSN: 0028-0836 , 1476-4687
    URL: Article
    DOI: 10.1038/nature11260
    RVK:
    TA 1000
    RVK:
    UA 1000
    RVK:
    WA 15000
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2012
    detail.hit.zdb_id: 120714-3
    detail.hit.zdb_id: 1413423-8
    SSG: 11
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  • 6
    Online Resource
    Online Resource
    Association between coronary lesion severity and distal microvascular resistance in patients with coronary artery disease
    American Physiological Society ; 2003
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 285, No. 5 ( 2003-11), p. H2194-H2200
    Details
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 285, No. 5 ( 2003-11), p. H2194-H2200
    Abstract: Homogeneity of microvascular resistance in different perfusion areas of the same heart is generally assumed. We investigated the effect of the severity of an epicardial stenosis on microvascular resistance in 27 patients with coronary artery disease and stable angina. All patients had an angiographically normal coronary artery, an artery with an intermediate lesion, and an artery with a severe lesion; the latter was treated with angioplasty. In each patient, distal blood flow velocity and pressure were measured during baseline and maximal hyperemia (induced by intracoronary adenosine) using a Doppler and pressure guide wire, respectively. The ratio of mean distal pressure to average peak blood flow velocity was used as an index for the microvascular resistance (MR v ). Within patients, the hyperemic MR v was higher in arteries with more severe stenosis ( P = 0.021). After percutaneous transluminal coronary angioplasty (PTCA), the hyperemic MR v decreased (pre-PTCA, 2.6 vs. post-PTCA, 1.9 mmHg·cm –1 s –1 , P 〈 0.01) toward the value of the reference artery (1.7 mmHg·cm –1 s –1 ; P = 0.67). We conclude that there is a positive association between coronary lesion severity and variability of distal microvascular resistance that normalizes after angioplasty. This study challenges the concept of uniform distribution of hyperemic MR v that is relevant for the interpretation of both noninvasive and invasive diagnostic tests.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    URL: Article
    DOI: 10.1152/ajpheart.01021.2002
    RVK:
    WA 15000
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2003
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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  • 7
    Online Resource
    Online Resource
    Prevalence of microvascular angina among patients with stable symptoms in the absence of obstructive coronary artery disease: a systematic review
    Oxford University Press (OUP) ; 2022
    In:  Cardiovascular Research Vol. 118, No. 3 ( 2022-02-21), p. 763-771
    Details
    In: Cardiovascular Research, Oxford University Press (OUP), Vol. 118, No. 3 ( 2022-02-21), p. 763-771
    Abstract: Our purpose was to perform a systematic review to assess the prevalence of microvascular angina (MVA) among patients with stable symptoms in the absence of obstructive coronary artery disease (CAD). We performed a systematic review of the literature to group the prevalence of MVA, based on diagnostic pathways and modalities. We defined MVA using three definitions: (i) suspected MVA using non-invasive ischaemia tests; proportion of patients with non-obstructive CAD among patients with symptoms and a positive non-invasive ischaemia test result, (ii) suspected MVA using specific modalities for MVA; proportion of patients with evidence of impaired microvascular function among patients with symptoms and non-obstructive CAD, and (iii) definitive MVA; proportion of patients with positive ischaemia test results among patients with an objectified impaired microvascular dysfunction. We further examined the ratio of women-to-men for the different groups. Of the 4547 abstracts, 20 studies reported data on MVA prevalence. The median prevalence was 43% for suspected MVA using non-invasive ischaemia test, 28% for suspected MVA using specific modalities for MVA, and 30% for definitive MVA. Overall, more women were included in the studies reporting sex-specific data. The women-to-men ratio for included participants was 1.29. However, the average women-to-men ratio for the MVA cases was 2.50. In patients with stable symptoms of ischaemia in the absence of CAD, the prevalences of suspected and definitive MVA are substantial. The results of this study should warrant cardiologists to support, promote and facilitate the comprehensive evaluation of the coronary microcirculation for all patients with symptoms and non-obstructive CAD.
    Type of Medium: Online Resource
    ISSN: 0008-6363 , 1755-3245
    URL: Article
    DOI: 10.1093/cvr/cvab061
    RVK:
    WA 15000
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2022
    detail.hit.zdb_id: 1499917-1
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  • 8
    Online Resource
    Online Resource
    Influence of hemodynamic conditions on fractional flow reserve: parametric analysis of underlying model
    American Physiological Society ; 2002
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 283, No. 4 ( 2002-10-01), p. H1462-H1470
    Details
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 283, No. 4 ( 2002-10-01), p. H1462-H1470
    Abstract: Pressure-based fractional flow reserve (FFR) is used clinically to evaluate the functional severity of a coronary stenosis, by predicting relative maximal coronary flow (Q s /Q n ). It is considered to be independent of hemodynamic conditions, which seems unlikely because stenosis resistance is flow dependent. Using a resistive model of an epicardial stenosis (0–80% diameter reduction) in series with the coronary microcirculation at maximal vasodilation, we evaluated FFR for changes in coronary microvascular resistance ( R cor = 0.2–0.6 mmHg · ml −1 · min), aortic pressure (P a = 70–130 mmHg), and coronary outflow pressure (P b = 0–15 mmHg). For a given stenosis, FFR increased with decreasing P a or increasing R cor . The sensitivity of FFR to these hemodynamic changes was highest for stenoses of intermediate severity. For P b 〉 0, FFR progressively exceeded Q s /Q n with increasing stenosis severity unless P b was included in the calculation of FFR. Although the P b -corrected FFR equaled Q s /Q n for a given stenosis, both parameters remained equally dependent on hemodynamic conditions, through their direct relationship to both stenosis and coronary resistance.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    URL: Article
    DOI: 10.1152/ajpheart.00165.2002
    RVK:
    WA 15000
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2002
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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  • 9
    Online Resource
    Online Resource
    Windkesselness of coronary arteries hampers assessment of human coronary wave speed by single-point technique
    American Physiological Society ; 2008
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 295, No. 2 ( 2008-08), p. H482-H490
    Details
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 295, No. 2 ( 2008-08), p. H482-H490
    Abstract: A novel single-point technique to calculate local arterial wave speed ( SPc) has recently been presented and applied in healthy human coronary arteries at baseline flow. We investigated its applicability for conditions commonly encountered in the catheterization laboratory. Intracoronary pressure (P d ) and Doppler velocity ( U) were recorded in 29 patients at rest and during adenosine-induced hyperemia in a distal segment of a normal reference vessel and downstream of a single stenosis before and after revascularization. Conduit vessel tone was minimized with nitroglycerin. Microvascular resistance (MR) and SPc were calculated from P d and U. In the reference vessel, SPc decreased from 21.5 m/s (SD 8.0) to 10.5 m/s (SD 4.1) after microvascular dilation ( P 〈 0.0001). SPc was substantially higher in the presence of a proximal stenosis and decreased from 34.4 m/s (SD 18.2) at rest to 27.5 m/s (SD 13.4) during hyperemia ( P 〈 0.0001), with a concomitant reduction in P d by 20 mmHg and MR by 55.4%. The stent placement further reduced hyperemic MR by 26% and increased P d by 26 mmHg but paradoxically decreased SPc to 13.1 m/s (SD 7.7) ( P 〈 0.0001). Changes in SPc correlated strongly with changes in MR ( P 〈 0.001) but were inversely related to changes in P d ( P 〈 0.01). In conclusion, the single-point method yielded erroneous predictions of changes in coronary wave speed induced by a proximal stenosis and distal vasodilation and is therefore not appropriate for estimating local wave speed in coronary vessels. Our findings are well described by a lumped reservoir model reflecting the “windkesselness” of the coronary arteries.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    URL: Article
    DOI: 10.1152/ajpheart.00223.2008
    RVK:
    WA 15000
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2008
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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  • 10
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    Online Resource
    Anti-tumor necrosis factor-α therapies attenuate adaptive arteriogenesis in the rabbit
    American Physiological Society ; 2005
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 289, No. 4 ( 2005-10), p. H1497-H1505
    Details
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 289, No. 4 ( 2005-10), p. H1497-H1505
    Abstract: The specific antagonists of tumor necrosis factor-α (TNF-α), infliximab and etanercept, are established therapeutic agents for inflammatory diseases such as rheumatoid arthritis and Crohn’s disease. Although the importance of TNF-α in chronic inflammatory diseases is well established, little is known about its implications in the cardiovascular system. Because proliferation of arteriolar connections toward functional collateral arteries (arteriogenesis) is an inflammatory-like process, we tested in vivo the hypothesis that infliximab and etanercept have antiarteriogenic actions. Sixty-three New Zealand White rabbits underwent femoral artery occlusion and received infliximab, etanercept, or vehicle according to clinical dosage regimes. After 1 wk, collateral conductance, assessed with fluorescent microspheres, revealed significant inhibition of arteriogenesis (collateral conductance): 52.4 (SD 8.1), 35.2 (SD 7.7), and 33.3 (SD 10.1) ml·min −1 ·100 mmHg −1 with PBS, infliximab, and etanercept, respectively ( P 〈 0.001). High-resolution angiography showed no significant differences in number of collateral arteries, but immunohistochemical analysis demonstrated a decrease in mean collateral diameter, proliferation of vascular smooth muscle cells, and reduction of leukocyte accumulation around collateral arteries in treated groups. Infliximab and etanercept bound to infiltrating leukocytes, which are important mediators of arteriogenesis. Infliximab induced monocyte apoptosis, and neither substance affected monocyte expression of the adhesion molecule Mac-1. We demonstrated that TNF-α serves as a pivotal modulator of arteriogenesis, which is attenuated by treatment with TNF-α inhibitors. Reduction of collateral conductance is most likely due to inhibition of perivascular leukocyte infiltration and subsequent lower vascular smooth muscle cell proliferation. This is the first report showing a negative influence of TNF-α inhibitors on collateral artery growth.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    URL: Article
    DOI: 10.1152/ajpheart.00959.2004
    RVK:
    WA 15000
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2005
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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