Spectral analysis of doppler flow velocity signals: Assessment of objectives, methods, and interpretation

This observational type of descriptive study was carried out in the Department of Radiology and Imaging, BIRDEM selecting 70 Bangladeshi pregnant babies with the aim to find out the normogram of foetal middle cerebral artery Doppler flow velocity indices and correlation between Doppler flow velocity indices [Resistance Index (RI), Pulsatility Index (PI), Systolic/Diastolic ratio (S/D) & Peak Systolic Velocity (PSV)] of foetal middle cerebral artery and gestational age in normal pregnancies of 20 to 40 weeks. It was observed that RI, PI and S/D were decreased with the advance of gestational age but PSV was increases with the advance of gestational age. Statistical analyses showed there were significant difference between mean PSV, RI and PI before and after 25 weeks of gestation. No significant difference was found between mean S/D before and after 25 weeks of gestation. It was observed from Correlation analysis between Doppler indices with independent gestational age that all the Doppler indices of foetal middle cerebra artery was positively correlated with the whole gestation period. The statistical analysis showed only PSV and RI were significantly correlated with the gestational age. Simple regression analysis between dependent Doppler index with independent gestational age before and after 25 weeks revealed that all the Doppler indices had positive relationship with the corresponding gestational age but relationship between PSV and PI (before 25 weeks) with their corresponding gestational ages were only statistically significant.DOI: http://dx.doi.org/10.3329/birdem.v2i2.12306 Birdem Med J 2012; 2(2) 77-80

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The Association Between Notching of the Right Ventricular Outflow Tract Flow Velocity Doppler Envelope and Impaired Right Ventricular Function After Acute High-Altitude Exposure

Frontiers in Physiology ◽

10.3389/fphys.2021.639761 ◽

2021 ◽

Vol 12 ◽

Author(s):

Fangzhengyuan Yuan ◽

Chuan Liu ◽

Shiyong Yu ◽

Shizhu Bian ◽

Jie Yang ◽

...

Keyword(s):

Pulmonary Artery ◽

Right Ventricular ◽

Flow Velocity ◽

Healthy Subjects ◽

Right Ventricular Outflow Tract ◽

Ventricular Outflow Tract ◽

Tricuspid Annulus ◽

Doppler Flow ◽

The Right ◽

Rv Function

IntroductionPulmonary artery pressure (PAP) is increased and right ventricular (RV) function is well preserved in healthy subjects upon exposure to high altitude (HA). An increase in PAP may trigger notching of the right ventricular outflow tract Doppler flow velocity envelope (RVOT notch), which is associated with impaired RV function in patients with pulmonary hypertension. However, whether HA exposure can induce RVOT notch formation and the subsequent impact on cardiac function in healthy subjects remains unclear.MethodsA total of 99 subjects (69 males and 30 females) with a median age of 25 years were enrolled in this study; they traveled from 500 to 4100 m by bus over a 2-day period. All subjects underwent a comprehensive physiological and echocardiographic examination 1 day before ascension at low altitude and 15 ± 3 h after arrival at HA. The RVOT notch was determined by the presence of a notched shape in the RVOT Doppler flow velocity envelope. The systolic PAP (SPAP) was calculated as Bernoulli equation SPAP = 4 × (maximum tricuspid regurgitation velocity)2+5 and mean PAP (mPAP) = 0.61 × SPAP+2. Cardiac output was calculated as stroke volume × heart rate. Pulmonary capillary wedge pressure (PCWP) was calculated as 1.9+1.24 × mitral E/e’. Pulmonary vascular resistance (PVR) was calculated as (mPAP-PCWP)/CO.ResultsAfter HA exposure, 20 (20.2%) subjects had an RVOT notch [notch (+)], and 79 (79.8%) subjects did not have an RVOT notch [notch (−)]. In the multivariate logistic regression analysis, the SPAP, right ventricular global longitude strain (RV GLS), and tricuspid E/A were independently associated with the RVOT notch. The SPAP, mPAP, PVR, standard deviations of the times to peak systolic strain in the four mid-basal RV segments (RVSD4), peak velocity of the isovolumic contraction period (ICV), and the peak systolic velocity (s’) at the mitral/tricuspid annulus were increased in all subjects. Conversely, the pulse oxygen saturation (SpO2), RV GLS, and tricuspid annulus plane systolic excursion (TAPSE)/SPAP were decreased. However, the increases of SPAP, mPAP, PVR, and RVSD4 and the decreases of SpO2, RV GLS, and TAPSE/SPAP were more pronounced in the notch (+) group than in the notch (−) group. Additionally, increased tricuspid ICV and mitral/tricuspid s’ were found only in the notch (−) group.ConclusionHA exposure-induced RVOT notch formation is associated with impaired RV function, including no increase in the tricuspid ICV or s’, reduction of RV deformation, deterioration in RV-pulmonary artery coupling, and RV intraventricular synchrony.

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Changes of the Carotid Artery Doppler Flow Velocity Pattern after Sublingual Nitroglycerin in Patients with Hypertension

The Korean Journal of Internal Medicine ◽

10.3904/kjim.1998.13.1.22 ◽

1998 ◽

Vol 13 (1) ◽

pp. 22-26

Author(s):

Jin Won Jeong ◽

Ock Kyu Park ◽

Yang Kyu Park ◽

Chuwa Tei ◽

Nobuyuki Tanaka

Keyword(s):

Carotid Artery ◽

Flow Velocity ◽

Sublingual Nitroglycerin ◽

Doppler Flow ◽

Velocity Pattern

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Validity of Doppler Measurements of Anterior Cerebral Artery Blood Flow Velocity: Correlation with Brain Blood Flow in Piglets

PEDIATRICS ◽

10.1542/peds.72.4.526 ◽

1983 ◽

Vol 72 (4) ◽

pp. 526-531

Author(s):

Nancy B. Hansen ◽

Barbara S. Stonestreet ◽

Ted S. Rosenkrantz ◽

William Oh

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Flow Velocity ◽

Blood Flow Velocity ◽

Continuous Wave ◽

Anterior Cerebral Artery ◽

Brain Blood Flow ◽

Velocity Measurements ◽

Doppler Flow ◽

Continuous Wave Doppler

Continuous wave Doppler ultrasonography through the anterior fontanel has recently been used to assess changes in cerebral blood flow in human neonates. There has been controversy concerning whether measurements of Doppler blood flow velocity indeed correlate with brain blood flow. An in vivo correlation was performed between brain blood flow as measured by the microsphere method and Doppler flow velocity measurements of the cerebral arteries via an artificial fontanel in young piglets. The peak systolic velocity (r = .76, P < .001), end diastolic velocity (r = .72, P < .001) and area under the velocity curve (r = .86, P<.001) all showed significant positive correlations with brain blood flow. The pulsatility index did not correlate with brain blood flow. Although continuous wave Doppler flow velocity measurements of the anterior cerebral artery cannot quantitatively assess cerebral blood flow, this methodology can be used to correlate changes in cerebral blood flow and provide a meaningful trend analysis following physiologic or pharmacologic perturbation of the cerebral circulation.

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Computer Analysis of Coronary Doppler Flow Velocity

Encyclopedia of Healthcare Information Systems ◽

10.4018/978-1-59904-889-5.ch038 ◽

2008 ◽

pp. 281-289

Author(s):

Valentina Magagnin ◽

Maurizio Turiel ◽

Sergio Cerutti ◽

Luigi Delfino ◽

Enrico Caiani

Keyword(s):

Blood Flow ◽

Coronary Artery ◽

Flow Velocity ◽

Coronary Blood Flow ◽

Doppler Echocardiography ◽

Coronary Flow ◽

Connective Tissue Diseases ◽

Doppler Flow ◽

Intracoronary Doppler ◽

Artery Disease

The coronary flow reserve (CFR) represents an important functional parameter to assess epicardial coronary stenosis and to evaluate the integrity of coronary microcirculation (Kern, 2000; Sadamatsu, Tashiro, Maehira, & Yamamoto, 2000). CFR can be measured, during adenosine or dipyridamole infusion, as the ratio of maximal (pharmacologically stimulated) to baseline (resting) diastolic coronary blood flow peak. Even in absence of stenosis in epicardial coronary artery, the CFR may be decreased when coronary microvascular circulation is compromised by arterial hypertension with or without left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, syndrome X, hypertrophic cardiomyopathy, and connective tissue diseases (Dimitrow, 2003; Strauer, Motz, Vogt, & Schwartzkopff, 1997). Several methods have been established for measuring CFR: invasive (intracoronary Doppler flow wire) (Caiati, Montaldo, Zedda, Bina, & Iliceto, 1999b; Lethen, Tries, Brechtken, Kersting, & Lambertz, 2003a; Lethen, Tries, Kersting, & Lambertz, 2003b), semi-invasive and scarcely feasible (transesophageal Doppler echocardiography) (Hirabayashi, Morita, Mizushige, Yamada, Ohmori, & Tanimoto, 1991; Iliceto, Marangelli, Memmola, & Rizzon, 1991; Lethen, Tries, Michel, & Lambertz, 2002; Redberg, Sobol, Chou, Malloy, Kumar, & Botvinick, 1995), or extremely expensive and scarcely available methods (PET, SPECT, MRI) (Caiati, Cioglia, Montaldo, Zedda, Rubini, & Pirisi, 1999a; Daimon, Watanabe, Yamagishi, Muro, Akioka, & Hirata, 2001; Koskenvuo, Saraste, Niemi, Knuuti, Sakuma, & Toikka, 2003; Laubenbacher, Rothley, Sitomer, Beanlands, Sawada, & Sutor, 1993; Picano, Parodi, Lattanzi, Sambuceti, Andrade, & Marzullo, 1994; Saraste, Koskenvuo, Knuuti, Toikka, Laine, & Niemi, 2001; Williams, Mullani, Jansen, & Anderson, 1994), thus their clinical use is limited (Dimitrow, 2003). In addition, PET and intracoronary Doppler flow wire involve radiation exposure, with inherent risk, environmental impact, and biohazard connected with use of ionizing testing (Picano, 2003a). In the last decade, the development of new ultrasound equipments and probes has made possible the noninvasive evaluation of coronary blood velocity by Doppler echocardiography, using a transthoracic approach. In this way, the peak diastolic coronary flow velocity reserve (CFVR) can be estimated as the ratio of the maximal (pharmacologically stimulated) to baseline (resting) diastolic coronary blood flow velocity peak measured from the Doppler tracings. Several studies have shown that peak diastolic CFVR, computed in the distal portion of the left anterior descending (LAD) coronary artery, correlates with CFR obtained by more invasive techniques. This provided a reliable and non invasive tool for the diagnosis of LAD coronary artery disease (Caiati et al., 1999b; Caiati, Montaldo, Zedda, Montisci, Ruscazio, & Lai, 1999c; Hozumi, Yoshida, Akasaka, Asami, Ogata, & Takagi, 1998; Koskenvuo et al., 2003; Saraste et al., 2001).

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