Normal Echocardiographic Values Research Articles

Racial Differences in Age-Related Changes in Left Ventricular Structural and Functional Echocardiographic Measurements Among Healthy Japanese and American Participants - A Subanalysis of the World Alliance Society of Echocardiography Normal Values Study.

Age-related changes in left ventricular (LV) structure and function lower the threshold for the onset of heart failure with preserved ejection fraction (HFpEF). LV parameters change also with race; however, the racial differences in age-related changes in LV parameters with and without adjustment for body mass index (BMI), heart rate (HR), and blood pressure (BP) remain unclear. We performed a subanalysis of the World Alliance Society of Echocardiography Normal Values Study, an international cross-sectional study that examined normal echocardiographic values in 15 countries. The age-related changes in 2-dimensional echocardiographic derived parameters including LV size, systolic function, and mass, were compared between healthy Japanese (n=227) and healthy White (n=98) and Black (n=69) American participants. In men, age-related changes in all parameters did not differ significantly among races. However, compared with Japanese women, White American women had a smaller body surface area (BSA)-indexed LV volume, BSA-indexed LV internal dimension at end-systole, BSA-indexed LV stroke volume, and LV mass index to BSA, and a larger LV ejection fraction with age, even after adjusting for BMI, HR, and BP. Age-related changes in LV structure and function, which are important for the pathophysiology of HFpEF, may differ by race. Therefore, future studies examining echocardiographic reference values for each age group in each race are needed.

Echocardiographic Measurements in Normal Healthy Adult Population of North India.

Interpretation of imaging modalities depends on robust normal reference limits. Ethnicity is an essential determinant of cardiac chamber sizes. Though few studies from India have focused on this research, it has yet to include the Kashmiri population. We aimed to study normal echocardiographic values of healthy Kashmiri adults and compare them with Western and Indian studies. It was a prospective observational study on healthy adults of Kashmir Valley. A comprehensive echocardiographic analysis following standardized protocols was performed. A total of 2245 study participants were analyzed. The mean age was 32.52±11.55 years. There were 1100 (49%) males. Males had higher absolute left ventricular volumes and mass, left atrial volumes, right ventricular diameter, and aortic size, while females had higher absolute left ventricular ejection fraction and early and late diastolic mitral inflow velocities. Males had higher indexed left ventricular end-systolic volume, while females had higher indexed left ventricular end diastole diameter, aorta diameter, right ventricle, and left and right atrial sizes. Left ventricular mass and diastolic parameters were significantly associated with age. Compared with the American Society of Echocardiography/European Association of Cardiovascular Imaging, absolute values of left ventricle size, volumes, mass, right ventricle size, aortic size, and left and right atrial size were higher than those in our study. Our study population had a higher left ventricle ejection fraction. Among indexed parameters, left ventricle volumes, left ventricle systolic diameter, aortic annulus, and left and right atrial volumes were still significantly higher in Western data. While comparing with Indian data, we noted significant regional differences. We provide normal reference values for our local population. We noted significant differences with Western as well as other Indian populations. Our study highlights the need for developing ethnic-specific reference values of various echocardiographic measurements.

Chamber sizes and left ventricular mass in sub-Saharan Africans: Normal echocardiographic values from the TAHES study

Reported ranges of normal echocardiographic values for chambers size or left ventricular (LV) mass are mostly issued from Caucasian cohorts and they may not be representative of diverse world population. Our study aimed to establish reference values in a community-dwelling Beninese population cohort. This study is a part of TAHES, a population-based prospective cohort study initiated in 2015 in Benin. Overall transthoracic echocardiography examinations were performed by 4 cardiologist, and analyzed off-line by a single observer. Interventricular septal (IVSWT), posterior wall thicknesses (PWT) and LV internal diameters were measured from the parasternal long-axis acoustic window in M mode. The LV mass was calculated from linear measurements obtained from parasternal views. LV, left atrial (LA) and right atrial (RA) volumes were measured using the discs’ summation method. Normal limits were defined as the 95th percentiles. We included 513 normotensive individuals (206 men and 307 women, age 40 ± 14 years, BSA 1.59 ± 0.18 m 2 ). End-diastolic IVSWT, LV internal diameter, PWT, and systolic LV internal diameter were respectively 10.4 ± 2.5, 48 ± 5, 9.8 ± 1.9, 15 ± 2.7 mm for men and 9.1 ± 2.4, 45 ± 4.3, 9 ± 1.8, 13.2 ± 2.5 mm for women. LV mass was significantly greater in men (172 ± 53 vs. 135 ± 37 g). Upper limits of LV mass were 260 g for men and 206 g for women. There was a correlation between LV mass and age in both sexes ( r = 0.20, P < 0.0001). The indexed values with the upper limits are summarized in Table 1 . Normal values in West Africa differ from those established in Caucasian populations with greater LV mass, wall thicknesses and LV sizes.

Two-dimensional, M-mode, and Doppler echocardiography in 22 conscious and apparently healthy pet guinea pigs

ObjectivesThe objective of this study was to report normal echocardiographic values in healthy guinea pigs. Animals, materials, and methodsTwenty-two privately owned, apparently healthy, conscious guinea pigs underwent complete transthoracic echocardiography. Left ventricular (LV), right ventricular, left atrial, and aortic root dimensions were measured, as were forward flow velocities across the mitral, aortic, and pulmonic valves. The effects of age, body weight, sex, and heart rate on these variables were also investigated. ResultsThe median age (interquartile range) was 3.0 (1.8–4.0) years with a body weight of 902 (822–998) grams. Echocardiography was feasible in all conscious animals. Early and late diastolic transmitral flow waves were summated in 17 of 22 individuals. In the remaining five animals, the two waves were reversed (E wave-to-A wave velocity less than 1.0). A positive correlation was detected between body weight and LV internal diameter at end-diastole and end-systole and left atrial diameter (P < 0.05). Heart rate was negatively correlated with LV internal diameter at end-systole (r = −0.463, P = 0.035). Age was positively correlated with LV posterior wall thickness at end-diastole and aortic diameter (P < 0.05). LV internal diameter at end-systole was larger in males than in females (P = 0.012), while fractional shortening was lower (P = 0.008). ConclusionsDescriptive echocardiography ranges in apparently healthy awake guinea pigs have been provided and can be used for cardiac assessment in these pet animals.

P1766 Comparison of left ventricular stroke volume in healthy adults among regions around the world: results from the World Alliance of Societies of Echocardiography (WASE) Normal Values Study

Abstract Funding Acknowledgements WASE Normal Values Study is sponsored by American Society Echocardiography Foundation. OnBehalf the WASE Investigators Background The American Society of Echocardiography (ASE) and the European Association of Cardiovascular Imaging (EACVI) chamber quantification guidelines provide normal reference values for a variety of size and function parameters. While used worldwide, these were predominantly obtained from American and European Caucasian populations and may not represent individuals from other regions around the world. Accordingly, ASE in collaboration with its International Alliance Partners conducted the World Alliance of Societies of Echocardiography (WASE) Normal Values Study to establish and compare normal echocardiographic values across races, ethnicities and countries worldwide. While most previous studies focused on left ventricular (LV) size and ejection fraction, LV stroke volume (SV) in healthy normal subjects has not been well defined. In this report, we aim to examine similarities and differences in normal LV SV indexed by body surface area (SVI) among regions around the world. Methods WASE Normal Values Study is a multinational, observational, cross-sectional study. Individuals free from known cardiac, lung and renal disease were prospectively enrolled with even distribution among age groups and gender. Echocardiographic images were acquired following a standardized protocol. LV SV was assessed by Doppler-derived (LVOT diameter and VTI) and two-dimensional (2D) biplane Simpson’s methods. LV SVI was calculated to account for differences in body size. These measurements were analyzed (TOMTEC) in a single core laboratory following ASE/EACVI Guidelines. Results As of May 2019, LV SV has been analyzed in 1164 cases from 13 countries, representing 8 distinct regions worldwide. In this population, age, body surface area and 2D LV ejection fraction were 47 ± 17 years old (range 18-87 years old), 1.76 ± 0.22 m² (range 0.95-2.44 m²) and 63.2 ± 2.9 % (range 52.7-73.7 %), respectively. LV SV and SVI by Doppler were larger than those obtained by 2D method in all regions. LV SV and SVI in both methods had significant differences among regions (p&amp;lt; 0.0001, Kruskal-Wallis test). LV SV and SVI in South Asia (India) were smallest in both methods and were also significantly smaller than other Asian regions (Figure). North America and Europe had largest LV SV and SVI by Doppler method, while Oceania had largest values by 2D. Conclusions The WASE Normal Values Study shows geographical variability in LV SVI across continents and countries. This information should be considered when determining normative values for SV and SVI. Abstract P1766 Figure.

Standard Strain and Strain Rate by Two-Dimensional Speckle Tracking in Agoutis (Dasyprocta prymnolopha) Anesthetized with Ketamine and Xylazine

Background: The agouti (Dasyprocta prymnolopha, Wagler, 1831) is a wild rodent widely found throughout America which has stood out as a good animal model for scientific investigations. The aim of this study was to study the cardiovascular function of chemically contained agoutis, by performing echocardiographic examinations and measuring Strain and Strain Rate by Speckle Tracking to obtain reference values for the species and verify the applicability of these animals as models for the study of cardiovascular changes in humans.Materials, Methods &amp; Results: It was selected 16 animals, sedated by the combination of ketamine hydrochloride and xylazine and submitted to transthoracic echocardiography. To obtain the standard measurements, B, M and Doppler mode images were taken. The analysis of the radial and longitudinal myocardial deformation of the left ventricle was carried out. The right parasternal window was used for access to the short cardiac axis and the left for access to the long axis. Six radial profiles of strain (ST) and Strain rate (SR) values were obtained, corresponding to the mean of the values for each segment. A total of 18 myocardial segments were analyzed for each specimen and the mean values were used to compose the statistical analysis. The comparison of the means between the genders did not show statistical difference, being the other statistical treatments based on the total sample of 16 animals. The variables that showed statistically significant correlation coefficients in relation to weight were: LA, LA/AO, HR, AVmax, E’ wave, E/IVRT (P &gt; 0.05). HR showed a positive correlation with IVSd (r = 0.51), EPSS (r = 0.55) and E’ wave (r = 0.68); negative with IVRT (r = - 0.41), A wave (r = - 0.54), AVmax (r = - 0.53) and Pmax (r = - 0.65).Discussion: Although presumptively normal echocardiographic values were reported for not anesthetized agoutis, this was the first study to show the measurement of these variables for chemically contained agoutis, in addition to the use of Strain and strain rate by speckle tracking in the assessment of cardiac function. The sudden exposure of an external stimulus (environmental or physical) to which the body is not adapted can trigger an acute stress, and its effects may interfere significantly in the measurement of hemodynamic variables, justifying the need for chemical containment. The values found for the thickness of agoutis cardiac walls and chambers obtained in M mode, both in systole and in diastole, when compared with mammals of different size, confirm the positive linear correlation between body weight and cardiac dimensions for the various evaluated parameters. The velocity obtained by the Strain radial for the apical systolic peak was slightly lower than that obtained for the basal systolic peak, while the opposite was observed for the circumferential Strain, which showed apical peak greater than the basal peak, also to the found for human beings. The values obtained for circumferential, radial and longitudinal strain for agoutis were within the ranges of normality observed in healthy domestic animals and humans.

M-mode echocardiographic reference values in Pantja goats.

Aim:The aim of this study was to establish M-mode echocardiographic reference values in Pantja goats and to study the effect of gender and body weight (BW) on these parameters.Materials and Methods:A total of 18, clinically healthy, adult Pantja goats of either sex, aged 2-4 years and weighing 10-44 kg were included in the study. Echocardiographic examination was performed in the standing unsedated animal. All measurements were made from the right parasternal long-axis left ventricular outflow tract view of the heart. The following parameters were recorded: Left ventricular internal diameter at diastole and systole, interventricular septal thickness at diastole and systole, left ventricular posterior wall (LVPW) thickness at diastole and systole, end diastolic and systolic volumes, stroke volume, fractional shortening, ejection fraction, percent systolic thickening of interventricular septum, percent systolic thickening of LVPW, cardiac output, left atrial (LA) diameter at diastole and systole, aortic (AO) root diameter at diastole and systole, LA/AO, LA posterior wall thickness at diastole and systole, left ventricular ejection time, DE amplitude, EF slope, AC interval and e-point to septal separation.Results:This study demonstrated specific reference ranges of M-mode echocardiographic parameters and indices in healthy Pantja goats. Normal echocardiographic values obtained in Pantja goats were quite different from other goat breeds. Gender had no influence on echocardiographic parameters, while high correlations were found between most echocardiographic parameters and BW.Conclusion:The echocardiographic values obtained in the study may serve as a reference for future studies in this breed, for cardiovascular disease diagnosis and for utilizing the goat as a model for cardiac disorders in humans.

Normal 2-Dimensional Strain Values of the Left Ventricle: A Substudy of the Normal Echocardiographic Measurements in Korean Population Study.

BackgroundIt is important to understand the distribution of 2-dimensional strain values in normal population. We performed a multicenter trial to measure normal echocardiographic values in the Korean population.MethodsThis was a substudy of the Normal echOcardiogRaphic Measurements in KoreAn popuLation (NORMAL) study. Echocardiographic specialists measured frequently used echocardiographic indices in healthy people according to a standardized method at 23 different university hospitals. The strain values were analyzed from digitally stored images.ResultsOf a total of 1003 healthy participants in NORMAL study, 2-dimensional strain values were measured in 501 subjects (265 females, mean age 47 ± 15 years old) with echocardiographic images only by GE echocardiographic machines. Interventricular septal thickness, left ventricular (LV) posterior wall thickness, systolic and diastolic LV dimensions, and LV ejection fraction were 7.5 ± 1.0 mm, 7.4 ± 1.0 mm, 29.9 ± 2.8 mm, 48.9 ± 3.6 mm, and 62 ± 4%, respectively. LV longitudinal systolic strain (LS) values of apical 4-chamber (A4C) view, apical 3-chamber (A3C) view, apical 2-chamber (A2C) view, and LV global LS (LVGLS) were −20.1 ± 2.3, −19.9 ± 2.7, −21.2 ± 2.6, and −20.4 ± 2.2%, respectively. LV longitudinal systolic strain rate (LVLSR) values of the A4C view, A3C view, A2C view, and LV global LSR (LVGLSR) were −1.18 ± 0.18, −1.20 ± 0.21, −1.25 ± 0.21, and −1.21 ± 0.21−s, respectively. Females had lower LVGLS (−21.2 ± 2.2% vs. −19.5 ± 1.9%, p < 0.001) and LVGLSR (−1.25 ± 0.18−s vs. −1.17 ± 0.15−s, p < 0.001) values than males.ConclusionWe measured LV longitudinal strain and strain rate values in the normal Korean population. Since considerable gender differences were observed, normal echocardiographic cutoff values should be differentially applied based on sex.

Normal Echocardiographic Values of 368 Iranian Healthy Subjects

Background: Echocardiography is widely used to diagnose or exclude cardiac disease. The reports on reference values based on an Asian population are limited. Objectives: We conducted a study to determine normal values for two-dimensional, M-mode, and Doppler echocardiographic measurements and evaluate the relationship between these parameters and age and gender in a large, healthy Iranian population. Patients and Methods: Among a total of 400 volunteers in a cross-sectional study, 368 healthy individuals aged between 30 and 70 years [171 males at a mean age of 47.6 (9.9) and 197 females at a mean age of 47.6 (9.5)] were enrolled. Standard comprehensive transthoracic echocardiography (TTE) was performed based on the guidelines of the American Society of Echocardiography. The normal limits are presented as mean (SD) and are also indexed to body surface area (BSA). Results: There was no significant difference between the men and women regarding left ventricular (LV) ejection fraction (57.97% vs. 57.99%). The mean of LV end-diastolic diameter (LVEDD), LV end-systolic diameter (LVESD), interventricular septum (IVS), posterior wall (PW) thickness, and right ventricular diastolic diameter (RVDd) was significantly greater in the men than in the women. However, there was an inverse relationship when LVEDD, RVDd, and left atrial (LA) diameter and area were indexed to BSA. There was no significant difference in the mean of LA area between the males and females (14.28 vs. 13.6 cm2). The LV diastolic parameters correlated negatively with age. A peakE /A velocity ratio < 1 was found in the subjects over 50 years old. The mean of all the measurements in our study was less than the reference values in the published guidelines. Conclusions: Our study, the first and largest investigation of its kind, provides reference values for the echocardiographic evaluation of the cardiac size and function of Iranian healthy individuals. The mean of our measurements was significantly less than that reported in the published guidelines.

Normal Echocardiographic Findings in Four Month Old Male Ostrich (Struthio camelus)

Summary Echocardiography in birds is a useful and competent technique for morphological and functional cardiac assessment. The aim of this study was to establish normal reference echocardiographic values for ostrich. Echocardiographic parameters from 25 apparently healthy male and almost 4 month old ostrich were chosen for this experiment. Echocardiography was prepared from the second and third intercostals space and over the sternum. The mean and standard deviation was calculated for each parameter. The values obtained are: The left ventricular internal diameter at end systole and end diastole was 1.50±0.2 and 2.70±0.16 cm; left ventricular free wall at end systole and end diastole was 0.89±0.04 and 0.62±0.03 cm; inter ventricular septum at end systole and end diastole was 0.99±0.81 and 0.65±0.11 cm, respectively. The stroke volume was 20.98±2.56 cm 3 and fractional shortening was 44.41±0.53%. Normal echocardiographic values in the healthy birds may be used as early diagnostic and prognostic values in ostriches with cardiac diseases.

Are Normal Echocardiographic Values Obtained by Transthoracic Echocardiography in Awake Patients Suitable for Evaluation of Cardiac Function in Anesthetized and Mechanically Ventilated Patients?

Are Normal Echocardiographic Values Obtained by Transthoracic Echocardiography in Awake Patients Suitable for Evaluation of Cardiac Function in Anesthetized and Mechanically Ventilated Patients?

Are Normal Echocardiographic Values Obtained by Transthoracic Echocardiography in Awake Patients Suitable for Evaluation of Cardiac Function in Anesthetized and Mechanically Ventilated Patients?

To the Editor: In Table 3 of their recent review, Haddad et al.1 present normal values for the functional variables of the right ventricle. In the legend, the authors state that “almost all normal values had been established in nonventilated patients.” Although they stress the load dependency of the presented parameters, they offer no recommendation as to the application of these values in anesthetized and ventilated patients undergoing cardiac surgery, as they do not stress the age dependency of the tissue Doppler imaging parameters.2,3 In a prospective and randomized study, our group investigated right ventricular (RV) function in patients undergoing elective on-pump and off-pump coronary bypass surgery.4 The patients were clinically stable and had neither pulmonary hypertension nor a history of myocardial infarction involving the right ventricle. The day before surgery, they underwent transthoracic echocardiography that revealed normal RV global and regional function and no more than mild tricuspid regurgitation. The same patients were studied the next day using transesophageal echocardiography (TEE) after induction of balanced anesthesia, muscle relaxation, and intermittent positive pressure ventilation. TEE studies were performed during hemodynamic stability and normoventilation before opening the sternum. The transthoracic echocardiography and TEE values of three parameters obtained by spectral pulsed wave Doppler echocardiography in end expiration are reported in Table 1. The inferior tricuspid annular plane maximal systolic and diastolic velocities measured in the transgastric RV inflow view during general anesthesia and intermittent positive pressure ventilation4 were significantly less than those assessed during the preoperative transthoracic study in the awake and spontaneously breathing patients5 (submitted data). The measured values were also markedly less than those presented by Haddad et al. as normal values in Table 3 of their review. The lateral tricuspid annular plane maximal early diastolic velocities (Et) reported in our awake patients5 were slightly less than those reported as normal values,1–3 but quite comparable with the values reported by Alam6 in patients with coronary artery disease before bypass surgery, suggesting a possible preoperative diastolic dysfunction due to the coronary disease.Table 1: Echocardiographic Parameters in 50 Awake Patients During Spontaneous Breathing (TTE) and 1 Day Later During Balanced Anesthesia and Intermittent Positive Pressure Ventilation (TEE)David et al.7 also measured inferior tricuspid annular plane maximal systolic velocity in anesthetized coronary patients before opening the sternum and reported values of 5.2 ± 1.2 cm/s, which are similar to those in our patients during anesthesia and mechanical ventilation. These data show that general anesthesia, muscle relaxation, and mechanical ventilation have marked effects on tissue Doppler parameters of RV systolic and diastolic function. Therefore, applying reference values obtained from awake, spontaneously breathing subjects to anesthetized and mechanically ventilated patients is associated with the risk of falsely diagnosing impaired systolic or diastolic function in patients with preserved cardiac function. There is a clear need for studies to establish normal TEE values in anesthetized and mechanically ventilated patients, even if we are aware of the difficulty separating the effects of anesthesia from those of the disease, on the different Doppler parameters. Isabelle Michaux, MD Department of Intensive Care Medicine Mont-Godinne University Hospital Université Catholique de Louvain Belgium [email protected] Miodrag Filipovic, MD Manfred Seeberger, MD Karl Skarvan, MD Department of Anesthesia University Hospital Basel University of Basel Basel, Switzerland

Echocardiographic indices in normal German shepherd dogs

Sixty clinically normal German shepherd dogs, 31 males and 29 females, ranging in age from 1 and 5 years and with a body weight ranging from 22 to 37.2 kg, were examined by the two-dimensional mode, M-mode, and Doppler echocardiography. In Doppler mode, the mitral valve flows were obtained, where the aim was to determine the velocity peaks and ratios of the E and A waves and the mitral E wave deceleration time. The velocity peaks were obtained for the tricuspid, pulmonary and aortic valves. On the left ventricular outflow tract flow, the time velocity integral and aortic cross-sectional area was used to calculate the cardiac output. A statistically significant correlation with the body weight was found for the systolic left atrial and diastolic aortic diameter on two-dimensional mode. On M-mode, there was a significant correlation between the body weight and the systolic left atrium and diastolic aortic dimension, systolic and diastolic left ventricular, septal and posterior wall dimensions. Doppler echocardiography showed that there was no significant correlation between the body weight and the mitral, tricuspid, pulmonary and aortic valves flows. These results demonstrate that it is important to know the normal echocardiographic values for German shepherd dogs because there are some characteristics peculiar to this particular breed. The data obtained is expected to be helpful for studies on small animal cardiology.

Comparison of two-dimensional echocardiographic measurements of the left atrium in healthy dogs

The aim of the study was to establish normal echocardiographic values of the left atrium just above the mitral annulus (LAama) in healthy dogs. In the first part of the study 20 dogs of various breeds were examined. The diameter of the left atrium just above the mitral annulus (LAama) was compared to the linear (left to right) dimension of the left atrium (LAr-l) as published earlier. There was a linear relationship between LAr-l and the body weight (LAr-l = 0.5061 BW (kg) + 22.206; R2 = 0.81), but the proportion of LAr-l/LAama was independent of the body weight (LAr-l/LAama = 0.0004 BW (kg) + 1.0833; R2 = 0.01). In the second part of the study the left atrial diameter just above the mitral annulus (LAama) was measured in 121 dogs of various breeds. There was a positive linear relationship (R2 = 0.697; p < 0.001) between body weight and LAama (LAama = 0.54 BW (kg) + 18.502+/-4.76), but there were no significant correlations between the age of animals and LAama (p = 0.45) as well as between the gender of animals and LAama (p = 0.78). Two-dimensional echocardiographic (2DE) determination of LAama as described in the present study can be recommended for use in those dogs where measurement of LAr-l encounters technical difficulties. In these cases LAr-l can be calculated from LAama using the formula LAr-l/LAama = 0.0004 BW (kg) + 1.0833, worked out in the first experiment.

Two-dimensional and M-mode echocardiographic measurements of cardiac dimensions in healthy standardbred trotters.

The aim of the study was to establish normal echocardiographic values of healthy Standardbred trotters not published previously. Twenty-three clinically normal horses weighing between 350 and 490 kg were examined in the same manner: first a thorough physical and then detailed echocardiographic examination were performed. Standardised two-dimensional (2D) and guided M-mode echocardiographic imaging techniques were used to measure interventricular septal thickness (IVS), left ventricular internal diameter (LVID), left ventricular wall thickness (LVW), left atrial internal diameter (LAID) in end-systole (s) and end-diastole (d) and aortic diameter (AOD) in end-diastole. Mean, range and standard deviation of the different parameters were calculated. The mean values (in centimetres) were as follow (2D/M-mode): IVSs: 4.6/4.7; IVSd: 3.1/3.0; LVIDs: 7.0/7.0; LVIDd: 10.7/10.7; LVWs: 3.9/3.9; LVWd: 2.7/2.7; LAIDs: 10.4/-; LAIDd: 11.3/-; AODd: 7.2/-. Results of two-dimensional and M-mode measurements were compared to each other and to normal values obtained from other breeds.

A COMPARISON OF ECHOCARDIOGRAPHIC INDICES OF THE NONRACING, HEALTHY GREYHOUND TO REFERENCE VALUES FROM OTHER BREEDS

Echocardiographic evaluation of healthy, nonexercising, awake greyhounds revealed substantial differences in left ventricular cavity dimensions, wall thickness, systolic time intervals and fractional shortening as compared to previously reported normal echocardiographic values obtained from mongrels and various other dog breeds. Despite corrections for body surface area and body weight, these differences remained, suggesting that breed and body conformation should be considered when interpreting echocardiographic studies in the dog.

The diameter of coronary arteries in infants and children without heart disease.

Two-dimensional echocardiographic examinations of the proximal left and right coronary artery were performed in 100 children without heart disease. Fifty-nine boys and 41 girls were studied whose ages ranged from 1 day to 17 years old. The diameter of the proximal right and left coronary artery was 1 mm in newborns and 4.5 mm in teenagers. No significant difference was observed between male and female subjects. A linear correlation between the coronary artery dimensions and the patient's age, weight, length, and body surface area could be demonstrated. The closest linear correlation corresponded to the patient's length with a correlation coefficient of r = 0.91 and r = 0.89 for the right and the left proximal coronary artery respectively. A quick orientation concerning normality of coronary artery diameters is possible with our graph of body length and corresponding coronary artery size. Knowing normal echocardiographic values for proximal coronary artery diameters, even subtle changes of these vessels can be diagnosed and the number of invasive diagnostic procedures, e.g. in Kawasaki disease, can be reduced.

Echocardiographic measurements in normal subjects from infancy to old age.

Echocardiographic data from 92 younger normal subjects (1 month to 23 years of age) and 136 older normal subjects (20-97 years of age) were pooled and analyzed to obtain prediction equations for normal echocardiographic values. Using a bivariate regression model with the assumption that variability is constant as a percentage of the expected value, we developed regression equation and graphs that allow calculation of a 95% prediction interval for several echocardiographic measurements as a function of the subject's age and either body weight or body surface area. Body weight could be substituted for body surface area with no loss of precision. Further, examination of residuals showed that the linear prediction model fit well for all ages and all echocardiographic measurements studied. The measurements were obtained using the recently published standards recommended by the American Society of Echocardiography.

Echocardiographic measurements in normal subjects: Evaluation of an adult population without clinically apparent heart disease

In order to determine normal echocardiographic values for older subjects, we studied 136 adults (78 men and 58 women, 20 to 97 years of age) without evidence of cardiovascular disease. When patients were subdivided into six age groups, progressive changes were found in mean normal values for various parameters. Specifically, when the oldest group (over 70 years) was compared with the youngest group (21-30 years), significant (p less than 0.01) increases in aortic root (22 percent) and left atrial (16 percent) dimensions, in ventricular septal (20 percent) and left ventricular free-wall (18 percent) thicknesses, and in estimated left ventricular mass (15 percent) were noted. In addition, a significant (p less than 0.01) decrease in mean mitral E-F slope (43 percent) and slight decreases in mean left ventricular systolic and diastolic internal dimensions (5 and 6 percent, respectively; p less than 0.05) were noted. Left ventricular ejection fraction and percentage fractional shortening were found to be independent of age. These data have been used to derive regression equations that are related to both age and body surface area. The regression equations can be used to calculate mean normal values and 95 percent prediction intervals for echocardiographic measurements in adults.