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1.
OBJECTIVE: To use an index of myocardial performance (IMP) to assess right ventricular function in Boxers with arrhythmogenic right ventricular cardiomyopathy (ARVC). ANIMALS: 22 Boxers (12 Boxers with ARVC diagnosed by the detection of > or = 1,000 ventricular premature complexes (VPCs)/24 h and 10 Boxers with < or = 5 VPCs/24 h (control dogs). Procedures-Pulsed-wave Doppler recordings of tricuspid inflow and pulmonic outflow were acquired. Preejection period (PEP), ejection time (ET), PEP/ET, and IMP were determined for the right ventricle by use of data from separate cardiac cycles. RESULTS: A significant difference was not identified between groups for right ventricular PEP, right ventricular ET, right ventricular PEP/ET, or right ventricular IMP. Right ventricular IMP was not significantly correlated with VPC number (r = 0.21) or VPC grade (r = -0.3) in Boxers with ARVC. CONCLUSIONS AND CLINICAL RELEVANCE: Boxers with ARVC did not have significant differences in right ventricular IMP, compared with results for control Boxers. This would suggest that right ventricular dysfunction does not develop in Boxers with ARVC or that a more severe phenotype of the disease may be necessary for detection of dysfunction. Additional studies that use more sensitive techniques to evaluate myocardial function may be warranted.  相似文献   

2.
BACKGROUND: Pulmonary hypertension (PH) is commonly diagnosed by Doppler echocardiography (DE) of tricuspid regurgitation (TR). However, TR may be absent or difficult to measure. HYPOTHESIS: Doppler-derived systolic time intervals of pulmonary artery (PA) flow may be used to predict PH in dogs. ANIMALS: Seventy-three healthy dogs and 45 West Highland white terriers (WHWT) with interstitial pulmonary disease (IPD). METHODS: Echocardiographic studies, including determination of right ventricular acceleration time (AT), ejection time (ET), and AT : ET ratio; right ventricular shortening fraction (RV-SF); and TR velocity, were performed. Pulmonary hypertension was defined by TR >3.1 m/s. RESULTS: In healthy WHWT, AT (median, range) was 73 ms (53 to 104) and AT : ET was 0.40 (0.28 to 0.55). AT : ET was minimally affected by age (R2 = 0.04, 95% confidence interval [CI] 0.01-0.07, P < .001) but not by heart rate, body weight, or RV-SF. In all WHWT with TR, AT and AT : ET were inversely related to calculated systolic PA pressure (R2 = 0.52, 95% CI 0.42-0.62, P < .001 and R2 = 0.36, 95% CI 0.29-0.42, P = .001). Clinical cutoffs to predict systolic PH were defined for AT (58 ms; sensitivity [Se] 88% and specificity [Sp] 80%) and AT : ET (0.31; Se 73% and Sp 87%). CONCLUSION AND CLINICAL IMPORTANCE: PH is common in WHWT with IPD. Analysis of right ventricular AT and AT : ET may be predictive of PH and should be particularly useful if TR is absent.  相似文献   

3.
Recently, the Tei-index, a noninvasive index that combines systolic and diastolic time intervals, has been proposed to assess global cardiac performance. However, the effects of isoflurane on the Tei-index have not been characterized. This study aimed at studying the effects of 1.0 minimal alveolar concentration isoflurane anesthesia on the pre-ejection period (PEP), left ventricular ejection time (LVET), PEP/LVET ratio, isovolumic relaxation time (IVRT), stroke index (SI), cardiac index (CI), heart rate (HR), and the Tei-index in healthy unpremedicated dogs. We observed significant increases in PEP, PEP/LVET ratio, IVRT, and TEI, whose maximal increases obtained throughout the study were 47%, 48%, 78%, and 56%, respectively. The LVET and HR did not change significantly, whereas the SI and CI decreased during anesthesia (29% and 26%, respectively). In conclusion, isoflurane produced direct effects on the Tei-index. The changes in systolic and diastolic parameters were supportive of this finding and were consistent with an overall impairment of left ventricular function during anesthesia.  相似文献   

4.

Introduction

Left ventricular (LV) and left atrial (LA) enlargement affect management and outcome of dogs with cardiac disease. Short-axis, two-dimensional echocardiographic (2DE) images, indexed to the aorta (Ao), are frequently used to identify cardiomegaly. Long-axis images offer complementary views of the left heart.

Animals

Eighty healthy dogs and 25 dogs with MMVD.

Methods

Healthy dogs were prospectively recruited to determine reference intervals (Clinical Laboratory Standards Institute methodology) for long-axis ratios. Measurement variability and repeatability were quantified by intraclass correlation coefficient and coefficient of variation. Mean long-axis ratios from dogs with MMVD were compared with healthy dogs (unpaired t-test). In addition, the proportion of MMVD dogs exceeding the 97.5 percentile by LV/Ao and a conventional, allometric method were compared (McNemar’s test).

Results

Two-dimensional echocardiographic long-axis reference intervals were as follows: left ventricular to aortic dimension (LV/Ao) 1.8–2.5; left atrial to aortic dimension (LA/Ao) 1.8–2.4, and left atrial to left ventricular dimension (LA/LV) 0.9–1.1. Intraobserver and interobserver measurement agreement was good-to-excellent (intraclass correlation coefficients ≥0.84), and day-to-day variability was low (coefficient of variations <4%). Left ventricular to aortic dimension, LA/Ao, and LA/LV were significantly greater in canine MMVD compared with healthy dogs (p<0.001). The percentages of MMVD dogs demonstrating LV dilatation by LV/Ao and conventional method were 68% and 36%, respectively (p=0.043, 95% confidence interval for difference 7.9%, 56.1%).

Conclusions

Simple 2DE long-axis ratios of LV/Ao, LA/Ao, and LA/LV are repeatable and demonstrate clinical utility for identifying LV and LA enlargement in dogs with MMVD.  相似文献   

5.
Pulmonary hypertension (PH) is a common comorbidity in dogs with myxomatous mitral valve disease (MMVD), and can induce various changes in the right heart, such as right ventricular (RV) hypertrophy, dilatation, and dysfunction. We hypothesized that RV function, not only systolic function but also diastolic function, could be worsened with PH progression. We aimed to compare RV systolic and diastolic function in dogs with MMVD. Twenty healthy dogs and sixty-eight dogs with MMVD were enrolled. Dogs with MMVD were classified into the probability of PH. Two-dimensional and Doppler echocardiographic indices for right heart and two-dimensional speckle tracking echocardiography indices were measured. The morphological indicators of the right heart were significantly higher only in the high probability of PH group. The RV strain, early-diastolic and systolic strain rates were significantly lower in the high probability of PH group than those in the low and intermediate probability of PH groups. Multivariate analysis showed that increased RV internal dimension normalized by body weight and RV myocardial performance index were significantly associated with the presence of right-sided congestive heart failure. Speckle tracking echocardiography-derived RV systolic and diastolic function were activated in the low and intermediate probability of PH groups. However, dogs with high probability of PH showed RV myocardial dysfunction and dilatation. Increased RV myocardial performance index and end-diastolic RV internal dimension normalized by body weight were significantly associated with the presence of right-sided congestive heart failure in dogs with MMVD.  相似文献   

6.
The antiarrhythmic compound disopyramide has been shown to possess negative inotropic effects. The present study was conducted to establish the effects of graded doses of disopyramide on ventricular function and electrocardiograms from healthy, awake dogs. Electrocardiograms and echocardiograms were obtained during a control period, and during an experimental period in which the six dogs on test received 7.5, 15 or 30 mg disopyramide per kg body weight orally three times per day. Six other dogs served as vehicle controls. No changes of statistical significance occurred in heart rate. The PQ interval was prolonged at all doses, the QRS complex was prolonged only at the highest dose, and the QT interval was prolonged at the intermediate and high doses. Left ventricular pre-ejection period (PEP) was prolonged in a dose-dependent relationship, and the left ventricular ejection time (ET) was shortened only at the highest dose. The percent shortening fraction of the left ventricle (% delta D) decreased significantly at intermediate and high doses, while the ratio of pre-ejection period to ejection time increased in a dose-dependent relationship. Conclusions are that even in therapeutic levels disopyramide produces significant reduction in left ventricular function, and that ratio of PEP/ET correlates better with the dose of disopyramide than did % delta D. This study demonstrates the feasibility of evaluating cardiac effects of compounds by non-invasive means.  相似文献   

7.
The left ventricular (LV) Tei index (index of myocardial performance) has been demonstrated to be clinically useful in estimating comprehensive LV function, including the systolic and diastolic performances, in various human cardiac diseases. The purposes of this study were to validate the correlation between the LV Tei index and LV function obtained by cardiac catheterization in healthy dogs, and to evaluate the LV Tei index in dogs with naturally occurring mitral regurgitation (MR). In healthy dogs, the LV Tei index was significantly correlated with the LV peak +dP/dt (r = -0.89) and LV peak -dP/dt (r=0.87). The LV Tei index significantly increased in dogs with MR compared with normal dogs and significantly increased with progressively more severe clinical signs due to heart failure. The elevation of the LV Tei index in dogs with symptomatic MR appears to be associated with shortening of ejection time. The LV Tei index significantly increased with age and was not correlated with heart rate and body weight in normal dogs. In conclusion, our study demonstrated that the LV Tei index was measurable in dogs and not influenced by heart rate and body weight. The LV Tei index significantly increased with the progression of clinical signs in MR dogs. In particular, the elevation of the LV Tei index in dogs with symptomatic MR due to shortening of ejection time may suggest LV systolic dysfunction and the decrement of forward stroke volume.  相似文献   

8.
Seventeen clinically normal adult English Cocker Spaniels from a kennel population with a history of cardiomyopathy were assessed, using M-mode echocardiography, to establish reference values for left ventricular (LV) dimensions for this breed of dog. Echocardiographic measurements were compared with postmortem measurements in 10 of 17 dogs. The LV weight calculated from the echocardiographic measurements correlated significantly with LV weight at postmortem (P less than 0.05). Echocardiographic measurements of end diastolic and end systolic diameters for the 17 dogs correlated significantly with body surface area (P less than 0.01). Measurements of the interventricular septum were in close agreement with values in clinically normal dogs and were significantly correlated with postmortem measurements (r = 0.94, P less than 0.01). However, 76% of the measurements for LV caudal wall thickness in this group of dogs were above the normal range. Calculation of fractional shortening values identified a group of 5 dogs with reduced fractional shortening (mean +/- SD, 20.97 +/- 3.66%), which indicates that a depression in contractility may be present in some apparently healthy dogs of this kennel population. The remaining 12 dogs had fractional shortening values of mean +/- SD, 34.26 +/- 4.54%.  相似文献   

9.
Right ventricular (RV) Tei index (index of myocardial performance) has been demonstrated to be clinically useful in estimating RV function in various human cardiac diseases. The purposes of this study were to validate the correlation between RV Tei index and RV function obtained by cardiac catheterization in healthy dogs, and to evaluate the RV Tei index in dogs with tricuspid regurgitation (TR). In healthy dogs, the RV Tei index significantly correlated with the RV peak +dP/dt (r=-0.80, p<0.0001) and -dP/dt (r=0.69, p=0.0001). In normal dogs, the RV Tei index was not significantly correlated with heart rate, body weight, and age. The RV Tei index significantly increased in dogs with moderate to severe TR (0.39 +/- 0.35, p=0.0015), filariasis (0.46 +/- 0.16, p=0.0131), and trivial to mild TR and severe mitral regurgitation (MR; 0.61 +/- 0.14, p=0.0017) when compared with the normal dogs (0.17 +/- 0.10). In addition, the RV Tei index in dogs with TR significantly increased in association with pulmonary hypertension [PH(-), 0.19 +/- 0.09; PH(+), 0.65 +/- 0.14; respectively p<0.0001]. Our study has demonstrated that RV Tei index is a feasible approach to estimate RV function in dogs and is not influenced by heart rate, body weight, and aging. Further investigations are required to clarify the clinical significance of RV Tei index in dogs with right-sided cardiac diseases.  相似文献   

10.
BACKGROUND: Lactate concentrations are increasingly quantified in dogs using point-of-care instruments, but often without canine-specific method evaluation and instrument-specific reference intervals. OBJECTIVES: The objectives of this study were to 1) determine the precision of the Accutrend (Roche Diagnostics) for lactate determination in dogs, 2) determine the accuracy of the Accutrend using the Rapidlab 865 (Bayer Diagnostics) as the reference method, and 3) establish and compare reference intervals for lactate concentration in clinically healthy dogs for both instruments. METHODS: Precision was evaluated using low and high control materials, and variable (1 drop) and fixed (25 microL) sample volumes. Accuracy was determined by comparing lactate concentrations obtained with the Accutrend with those from the Rapidlab 865 in 273 heparinized canine jugular venous blood samples from 100 clinically healthy dogs and 107 systemically ill dogs (173 samples). Lactate reference intervals were established for both analyzers using data from the 100 clinically healthy dogs. RESULTS: The precision of the Accutrend was good (coefficients of variation, < or = 5.3%) for 25-microL samples but not when a drop was used. Lactate concentrations obtained on the Accutrend correlated poorly with those from the Rapidlab 865 (r = 0.864, mean bias = 0.66 mmol/L, 95% confidence interval [CI] = 0.57-0.76 with 95% limits of agreement = -0.87 (lower limit, 95% CI = -1.03 to -0.71) and 2.20 (upper limit, 95% CI = 2.04 to 2.36). The reference interval for canine lactate concentration on the Accutrend was 1.2-3.1 mmol/L compared with 0.46-2.31 mmol/L on the Rapidlab. CONCLUSION: Although precision was good with fixed sample volumes, blood lactate concentrations obtained on the Accutrend were significantly different than those on the Rapidlab 865, with systematic and random errors resulting in a positive bias. Further evaluation of the Accutrend is required before its use in dogs can be recommended.  相似文献   

11.
The echocardiographic characterization of a dilatation cardiomyopathy in small-breed dogs is reported. Twelve clinically healthy adult English Cocker Spaniel dogs (between 2 and 9 years old and weighing 11.5 to 15.4 kg [mean 12.9 +/- 1.00 kg]) from a kennel population with a history of cardiomyopathy were assessed, using M-mode echocardiography. The dogs were selected on ECG and/or radiographic evidence of ventricular enlargement. Nine dogs had R-wave amplitude in lead 11 of greater than 3.0 mV. Two dogs had an unusual right-axis deviation, the result of deep Q waves in the limb leads and deep S waves in chest leads CV6LL and CV6LU, indicating that there was right ventricular enlargement. All dogs had increased end-systolic dimensions (mean 3.0 +/- 0.6 cm). End-diastolic dimensions were increased in 9 dogs (mean 4.0 +/- 0.5 cm), and there was a decrease of left ventricular (LV) function as measured by fractional shortening in 8 dogs. Mean fractional shortening for the 12 dogs was 25.4 +/- 5.7%. There was significant correlation between LV dimensions and age at echocardiographic assessment, indicating that LV dilatation was progressive. Three of the oldest dogs had severe dilatation of the LV, and in 2 of these, LV function was severely decreased. Left ventricular function in the 3rd dog, however, was within the acceptable range. Fractional shortening and thickness of the LV caudal wall and interventricular septum were significantly correlated (P less than 0.01 for interventricular system and P less than 0.05 for LV caudal wall).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

12.
Hypobaric (high-altitude) hypoxia is a physiologic cause of pulmonary hypertension, and alters left ventricular (LV) systolic and diastolic function. In the presence of tricuspid regurgitation, systolic pulmonary artery pressure can be measured noninvasively using the peak tricuspid regurgitation velocity and the Bernoulli equation. In the absence of measurable tricuspid regurgitation, severity of pulmonary hypertension may be estimated using two-dimensional, M-mode, and Doppler-derived parameters. To evaluate the usefulness of echocardiographic parameters for detecting mild-to-moderate pulmonary hypertension caused by moderate-to-marked hypoxia and to study the effect of high-altitude hypoxia on systolic and diastolic LV function in dogs, 19 Greenland dogs were examined at moderate altitude (2300 m) and high altitude (3500 m), and 10 Greenland control dogs were examined at 700-900 m. Evaluated parameters were pulmonary flow profile (shape, right ventricular acceleration time (RVAT), ejection time (RVET), RVAT/ET), peak mitral inflow velocities (LVE, LVA, LVE/A-ratio), LV % fractional shortening (FS), systolic time intervals (LVPEP, LVPEP/ET), and stroke volume index (SVI). Notching during deceleration was common in dogs at high altitude and in the control dogs, but not in dogs at moderate altitude. RVAT was shorter in dogs at high altitude compared with moderate altitude, but not compared with control dogs. Peak A-velocity was higher and E/A-ratio was lower in dogs at high altitude compared with moderate altitude and control dogs. FS was increased in dogs at high altitude compared with moderate altitude, and LVPEP and LVPEP/ET were shorter in the dogs at high altitude compared with moderate altitude and control dogs. In conclusion, significant differences in pulmonary flow profiles and systolic and diastolic parameters can be observed echocardiographically in dogs at different degrees of hypobaric hypoxia. However, overlap between the groups compromises their usefulness for diagnosing and estimating the degree of mild-to-moderate pulmonary hypertension in individual dogs.  相似文献   

13.
The purpose of this prospective study was to determine comparability of left ventricular (LV) M-mode echocardiographic indices derived from right parasternal long-axis and short-axis imaging planes. In 104 dogs (37 healthy dogs and 67 dogs with heart disease), LV M-mode echocardiograms were recorded from both long-axis and short-axis views and interventricular septum thickness (IVS), left ventricular internal dimensions (LVD), left ventricular posterior wall thickness (LVPW), and LV shortening fraction (FS) were measured. Statistical analysis included paired t-test and graphical analysis to assess agreement between the two methods of data acquisition. Mean LVD in systole and diastole and mean IVS in systole were significantly (P<0.001) larger when measured from short-axis recordings compared to long-axis measurements. An increased magnitude of measurement resulted in increased differences between the methods for LV dimensions and fractional shortening. Differences between the two methods were small and within clinically acceptable limits in normal dogs. However, in 23 (34%) of the dogs with cardiac abnormality, one or more LV M-mode derived dimension obtained from one imaging plane did not agree sufficiently closely with the same measure from the other plane. Only for measurement of FS was there good agreement between methods in dogs with cardiac disease. Therefore, with the exception of FS, data gained from LV short-axis and long-axis M-mode recordings should not be used interchangeably in dogs with cardiac disease.  相似文献   

14.
To clarify time-related changes in equine cardiovascular system during maintenance anesthesia (180 min, 1.2 minimum alveolar concentration) with sevoflurane (Sev-group) compared to isoflurane (Iso-group) as the basis for clinical use of Sev, horses were examined for the heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), systemic vascular resistance (SVR) and pre-ejection period (PEP)/ejection time (ET) that is an index of the cardiac contractility. The HR was almost 30 beats/min in both groups without significant temporal change. MAP was significantly elevated with time but there was no significant difference between the groups. In the Sev-group, CI remained unchanged but the significant increase of CI with time was observed in the Iso-group. In the Sev-group SVR was significantly higher than that of the Iso-group and increased with time. No significant difference of PEP/ET was seen between the groups, but PEP/ET lowered with time in the Iso-group in association with prolonged ET. The results indicated that the time-dependent elevation of MAP in the Sev-group reflected increased SVR without increase of CI and that it reflected increased CI resulting from increased stroke volume in the Iso-group in association with lowered PEP/ET, that is, increased cardiac contractility.  相似文献   

15.
BACKGROUND: Tissue Doppler Imaging (TDI) or strain (St) imaging could provide sensitive indices for early detection and treatment follow-up of canine dilated cardiomyopathy (DCM). Analysis of TDI and St features in dogs with overt DCM is a prerequisite before using these new criteria in prospective screenings of predisposed families or in clinical trials. HYPOTHESIS: Radial and longitudinal right and left myocardial motion, assessed by TDI and St variables, is altered in dogs with DCM. ANIMALS: Case records for 26 dogs; 14 with DCM and 12 healthy controls of comparable age and weight were reviewed. METHODS: A retrospective analysis was conducted of conventional echocardiography, 2-dimensional color TDI, and St imaging data. RESULTS: The DCM group was characterized by decreases in radial and longitudinal systolic velocity gradients of the left ventricular free wall (LVFW), radial and longitudinal absolute values of peak systolic St of the LVFW, and longitudinal systolic right ventricular (RV) velocities (all P < .001 versus control) associated with longitudinal postsystolic contraction waves in 7/14 dogs. Early diastolic LVFW velocities also were decreased for longitudinal (P < .01) and radial (P < .05) motions. All radial LVFW, longitudinal basal LVFW, and RV systolic velocities were negatively correlated with heart rate (P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE: LV contractility along both the short and long axes is impaired in dogs with spontaneous DCM, as is systolic RV and diastolic LVFW function. These myocardial alterations are associated with an inverse force-frequency relationship. Studies now are needed to determine the comparative sensitivity of TDI and St variables for the early detection of canine DCM.  相似文献   

16.

Background

Right ventricular (RV) dysfunction independently predicts outcomes in human myxomatous mitral valve disease (MMVD). There is limited information regarding RV systolic function in dogs with MMVD.

Hypothesis

Right ventricular systolic function differs among stages of disease, decreasing in decompensated MMVD.

Animals

Thirty‐sixclient‐owned dogs with MMVD not receiving oral cardiovascular medications.

Methods

Prospective clinical study. Dogs were categorized according to disease severity as ACVIM Stage B1, B2, or C. Seven echocardiographic indices of RV systolic function were measured. Groups were compared by 1‐way ANOVA and Tukey's HSD test. Frequencies of cases with cardiac remodeling falling outside previously established reference intervals were compared using Fisher's exact test. Intra‐ and interobserver measurement variability was calculated for each RV function index.

Results

The indices TAPSE (P = 0.029), RV StL (P = 0.012), and RV StRL (P = 0.041) were significantly different between groups. A greater proportion of B2 dogs (7 of 12) had TAPSE values above reference intervals compared with B1 (2 of 12) or C (2 of 12) dogs (P = 0.027). Measurement variability of TAPSE, RV S', and RV StG was clinically acceptable.

Conclusions and Clinical Importance

Right ventricular systolic function differs between stages of MMVD, increasing in stage B2, and declining in stage C. The prognostic importance of RV function indices, particularly TAPSE, might be worth evaluating in dogs with MMVD.  相似文献   

17.

Objectives

To determine whether there are differences in measures of longitudinal right ventricular (RV) systolic function among Boxers with arrhythmogenic right ventricular cardiomyopathy (ARVC) compared with healthy control Boxer dogs. To explore relationships between markers of RV systolic function and age, body weight, gender, arrhythmia frequency, and markers of left ventricular (LV) systolic function in Boxer dogs.

Animals

The study included 50 client-owned Boxer dogs.

Methods

This is a retrospective echocardiographic study. Tricuspid annular plane systolic excursion (TAPSE) and pulsed wave tissue Doppler imaging–derived systolic myocardial velocity of the lateral tricuspid annulus (S') were measured in healthy control Boxers (n = 18), Boxers with ARVC and normal LV systolic function (n = 19), and Boxers with ARVC and reduced LV systolic function (n = 13).

Results

Tricuspid annular plane systolic excursion (p=0.002) and S' (p=0.001) were significantly different between affected and control groups. Significant correlations were found between measures of left heart size and function and both TAPSE and S'. No correlations were found between RV function parameters and age, gender, or body weight in this fairly homogeneous, single-breed population. Receiver operating characteristic curve analysis revealed that both TAPSE and S' had an area under the curve of 0.77 in distinguishing healthy Boxers from those with ARVC.

Conclusions

Tricuspid annular plane systolic excursion and S' are reduced in Boxers with ARVC. In contrast to prior studies evaluating these parameters in dogs of different breeds and body types, no correlation was found between markers of RV function and body weight in this population of Boxer dogs.  相似文献   

18.

Objectives

To create reference intervals for right ventricular outflow tract fractional shortening (RVOT-FS) in healthy dogs and examine diagnostic performance of this index in dogs with pulmonary hypertension (PH). In addition, we examine the impact of myxomatous mitral valve disease (MMVD) without PH on RVOT-FS.

Animals, materials and methods

The study population included 52 healthy adult dogs, 51 dogs with MMVD but without PH, and 51 dogs with PH. This is a prospective study. Complete echocardiographic evaluations were performed on all dogs. Right ventricular outflow tract fractional shortening was obtained by two-dimensional guided M-mode recordings from the right parasternal short axis view. Right ventricular outflow tract fractional shortening was evaluated in healthy dogs of various breeds, and reference intervals were generated. We examined the effect of PH on RVOT-FS with receiver operating characteristic analysis and evaluated the effect of MMVD on RVOT-FS in dogs without PH. Intraobserver and interobserver reproducibility was calculated.

Results

Healthy dogs had RVOT-FS > 44%. Right ventricular outflow tract fractional shortening values of healthy dogs and MMVD dogs without PH did not differ (p=0.84). In dogs with PH, RVOT-FS decreased with increasing tricuspid regurgitation velocity (p<0.0001). Pimobendan use in dogs with PH increased RVOT-FS as PH worsened. Right ventricular outflow tract fractional shortening was acquired with clinically acceptable intraobserver and interobserver reproducibility.

Conclusions

Right ventricular outflow tract fractional shortening is a novel, easy applicable, and repeatable index for evaluating RV systolic function. Studies comparing this index with common echocardiographic indices used to assess RV function in dogs are needed.  相似文献   

19.
The accuracy of Doppler-derived blood flow velocity depends on the angle of incidence between the ultrasound beam and the direction of flow. In dogs with subaortic stenosis, it is known that the subcostal transducer site provides higher left ventricular ejection velocities than does the apical site. Left ventricular ejection velocities obtained from the subcostal site in healthy dogs have not been reported; accordingly, we examined healthy, random-source dogs to test the hypothesis that aortic velocities obtained from the subcostal and apical transducer sites differ. In 38 unsedated dogs, high-pulsed repetition frequency (HPRF) and continuous-wave (CW) Doppler studies of the proximal aorta and left ventricular outflow tract were performed using two-dimensional echocardiographic guidance. The effects of Doppler modality, transducer site, and their interaction on peak aortic velocity were tested through the use of analysis of variance. P values less than 0.05 were considered to indicate significance. The mean (+/-SE) peak aortic velocities were as follows: subcostal site (HPRF) = 1.44 +/- 0.03; apical site (HPRF) = 1.39 +/- 0.03; subcostal site (CW) = 1.48 +/- 0.03; apical site (CW) = 1.39 +/- 0.03. Aortic velocities obtained from the subcostal site were significantly greater than those obtained from the cardiac apex (P = 0.0001). Lower and upper limits of 95% reference intervals for aortic velocities by method of measurement and transducer location are proposed. In a population of healthy dogs, peak aortic velocities obtained from the subcostal site exceeded those obtained from the cardiac apex but did so only to a marginal degree.  相似文献   

20.
A Doppler index of myocardial performance (IMP) has been recently proposed in human cardiology, which is calculated from the isovolumic contraction time (ICT), isovolumic relaxation time (IRT), and the ejection time (ET) using the following formula: (ICT+IRT)/ET. In this study, IMP was measured and evaluated in Newfoundland dogs categorized in four groups: Normal dogs (n = 31), dilated cardiomyopathy (DCM) (n = 34), depressed fractional shortening (dFS) (n = 27), and left ventricular enlargement (LVE) (n = 7). IMP was found to be independent of age, sex, body surface area, and the R-R interval in the Normal group. There were significant differences in IMP between the DCM group and the Normal and dFS groups (P < 0.05) and between Newfoundlands with overt vs. occult DCM. IMP is a Doppler index which appears to correlate with severity of disease and may be of use in the early diagnosis of affected dogs during screening for the presence of DCM.  相似文献   

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