Clinical physiology and functional imaging
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Clin Physiol Funct Imaging · Jan 2011
Measurement of cardiac output with non-invasive Aesculon impedance versus thermodilution.
This study compared the non-invasive thoracic electrical bioimpedance Aesculon technique (TEB(Aesculon) ) with thermodilution (TD) to evaluate whether TEB(Aesculon) may offer a reliable means for estimating cardiac output (CO) in humans. ⋯ TEB(Aesculon) overestimated CO compared to TD with ∼17% at rest and ∼34% during exercise, but the techniques showed similar results during NO inhalation. CO, furthermore, correlated poorly between TEB(Aesculon) and TD. TEB(Aesculon) may at present not replace TD for reliable CO measurements in humans.
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Clin Physiol Funct Imaging · Nov 2010
Randomized Controlled TrialThe influence of a fast ramp rate on peak cardiopulmonary parameters during arm crank ergometry.
The influence of a very fast ramp rate on cardiopulmonary variables at ventilatory threshold and peak exercise during a maximal arm crank exercise test has not been extensively studied. Considering that short arm crank tests could be sufficient to achieve maximal oxygen consumption (VO₂), it would be of practical interest to explore this possibility. Thus, this study aimed to analyse the influence of a fast ramp rate (20 W min⁻¹) on the cardiopulmonary responses of healthy individuals during a maximal arm crank ergometry test. ⋯ There was no other difference in ventilatory threshold and peak exercise variables when 1st and 2nd fast protocols were compared. Fast protocol seems to be useful when healthy young individuals perform arm cardiopulmonary exercise test. The usefulness of this protocol in other populations remains to be evaluated.
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Clin Physiol Funct Imaging · Nov 2010
Multicenter StudyANP, BNP and D-dimer predict right ventricular dysfunction in patients with acute pulmonary embolism.
The aim of this study was to predict right ventricular dysfunction (RVD) using plasma concentration of D-dimer, pro-atrial natriuretic peptide (pro-ANP), brain natriuretic peptide (BNP), endothelin-1 (ET-1) and cardiac troponin I (TNI) in patients with pulmonary embolism (PE). ⋯ Because measurements of cardiac biomarkers are inexpensive and easily obtained they may prove useful in the clinical diagnosis of RVD. However because of the small sample size, the results need to be confirmed in larger studies.
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Clin Physiol Funct Imaging · Sep 2010
Comparative StudyAudiocardiography in the cardiovascular evaluation of the morbidly obese.
Morbid obesity is believed to limit cardiovascular auscultation. We compared audiocardiography to senior attending physicians using conventional stethoscopes in 190 individuals with morbid obesity. Overall, there were 128 (67.4%) women and 62 (32.6%) men with mean ages of 44.9 +/- 12.3 and 51.3 +/- 10.8 , respectively (P = 0.001). ⋯ There were no significant correlations between BMI or peak oxygen consumption and S(3) or S(4) strength by audiocardiography. Acoustic cardiography performed with an electronic device was not helpful in assisting the cardiovascular examination of the morbidly obese. These data suggest the careful clinical exam with attention to traditional cardiac auscultation using a stethoscope in a quiet room should remain the gold standard.
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Clin Physiol Funct Imaging · Sep 2010
Elevated augmentation index derived from peripheral arterial tonometry is associated with abnormal ventricular-vascular coupling.
Although typically derived from the contour of arterial pressure waveform, augmentation index (AIx) may also be derived from the digital pulse volume waveform using finger plethysmography (peripheral arterial tonometry, PAT). Little is known regarding the physiologic correlates of AIx derived from PAT. In this study, we investigated the relation of PAT-AIx with measures of ventricular-vascular coupling. ⋯ Abnormal ventricular-vascular coupling, arising from either increased effective arterial elastance or increased ventricular elastance, is associated with increased AIx as measured by PAT. Additional research is needed to examine other vascular correlates of PAT-AIx.