GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • American Physiological Society  (2)
  • Biology  (2)
  • 1
    Online Resource
    Online Resource
    American Physiological Society ; 2010
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 299, No. 2 ( 2010-08), p. H364-H371
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 299, No. 2 ( 2010-08), p. H364-H371
    Abstract: The atria play an important role in cardiac performance. We evaluated their function and the atrioventricular interaction in operated patients with tetralogy of Fallot (TOF). Twenty patients who had undergone surgical repair of TOF and seven controls were investigated. Patients had residual pulmonary but no major tricuspid valve insufficiency. Atrial and ventricular strain rates were obtained by echocardiographic speckle tracking. Cine MRI-derived volumetric analysis provided atrial and ventricular time volume and time volume change curves yielding emptying and filling parameters. In addition, at the atrial level, reservoir, conduit and pump function, and cyclic volume change were calculated. At the atrioventricular valve level, tricuspid and mitral annular plane systolic excursion (TAPSE and MAPSE, respectively) were measured by two-dimensional echocardiography. In the patients compared with controls, right ventricular end-diastolic volumes were increased and biventricular ejection fraction was decreased (all P 〈 0.05). Biventricular measures of early diastolic ventricular filling were at control levels, but in late diastole, right ventricular filling parameters and strain rates were decreased ( P 〈 0.001). The maximal right atrial size was slightly but not significantly diminished, but cyclic volume change was significantly reduced ( P 〈 0.0001). Pump and reservoir function were decreased ( P 〈 0.05), and conduit function was elevated ( P 〈 0.001). The left atrium showed reduced reservoir function and cyclic volume change ( P 〈 0.05). TAPSE and MAPSE were also decreased ( P 〈 0.05). There were statistically significant interdependencies between RV ejection fraction, TAPSE, and right atrial filling and emptying parameters (all P 〈 0.05). In TOF patients, moderate systolic and diastolic right ventricular dysfunction is associated with clearly impaired right atrial function. The left atrium is affected to a lesser extent.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    RVK:
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2010
    detail.hit.zdb_id: 1477308-9
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 320, No. 2 ( 2021-02-01), p. H494-H510
    Abstract: Central blood pressure (cBP) is a highly prognostic cardiovascular (CV) risk factor whose accurate, invasive assessment is costly and carries risks to patients. We developed and assessed novel algorithms for estimating cBP from noninvasive aortic hemodynamic data and a peripheral blood pressure measurement. These algorithms were created using three blood flow models: the two- and three-element Windkessel (0-D) models and a one-dimensional (1-D) model of the thoracic aorta. We tested new and existing methods for estimating CV parameters (left ventricular ejection time, outflow BP, arterial resistance and compliance, pulse wave velocity, and characteristic impedance) required for the cBP algorithms, using virtual (simulated) subjects ( n = 19,646) for which reference CV parameters were known exactly. We then tested the cBP algorithms using virtual subjects ( n = 4,064), for which reference cBP were available free of measurement error, and clinical datasets containing invasive ( n = 10) and noninvasive ( n = 171) reference cBP waves across a wide range of CV conditions. The 1-D algorithm outperformed the 0-D algorithms when the aortic vascular geometry was available, achieving central systolic blood pressure (cSBP) errors ≤ 2.1 ± 9.7 mmHg and root-mean-square errors (RMSEs) ≤ 6.4 ± 2.8 mmHg against invasive reference cBP waves ( n = 10). When the aortic geometry was unavailable, the three-element 0-D algorithm achieved cSBP errors ≤ 6.0 ± 4.7 mmHg and RMSEs ≤ 5.9 ± 2.4 mmHg against noninvasive reference cBP waves ( n = 171), outperforming the two-element 0-D algorithm. All CV parameters were estimated with mean percentage errors ≤ 8.2%, except for the aortic characteristic impedance (≤13.4%), which affected the three-element 0-D algorithm’s performance. The freely available algorithms developed in this work enable fast and accurate calculation of the cBP wave and CV parameters in datasets containing noninvasive ultrasound or magnetic resonance imaging data. NEW & NOTEWORTHY First, our proposed methods for CV parameter estimation and a comprehensive set of methods from the literature were tested using in silico and clinical datasets. Second, optimized algorithms for estimating cBP from aortic flow were developed and tested for a wide range of cBP morphologies, including catheter cBP data. Third, a dataset of simulated cBP waves was created using a three-element Windkessel model. Fourth, the Windkessel model dataset and optimized algorithms are freely available.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    RVK:
    Language: English
    Publisher: American Physiological Society
    Publication Date: 2021
    detail.hit.zdb_id: 1477308-9
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...