Limits of the spatial ventricular gradient and QRST angles in patients with normal electrocardiograms and no known cardiovascular disease stratified by age, sex, and race.

INTRODUCTION: Measurement of the spatial ventricular gradient (SVG), spatial QRST angles, and other vectorcardiographic measures of myocardial electrical heterogeneity have emerged as novel risk stratification methods for sudden cardiac death and other adverse cardiovascular events. Prior studies of normal limits of these measurements included primarily young, healthy, White volunteers, but normal limits in older patients are unknown. The influence of race and body mass index (BMI) on these measurements is also unclear. METHODS: Normal 12-lead electrocardiograms (ECGs) from a single center were identified. Patients with abnormal cardiovascular, pulmonary, or renal history (assessed by International Classification of Disease [ICD-9/ICD-10] codes) or abnormal cardiovascular imaging were excluded. The SVG and QRST angles were measured and stratified by age, sex, and race. Multivariable linear regression was used to assess the influence of age, BMI, and heart rate (HR) on these measurements. RESULTS: Among 3292 patients, observed ranges of SVG and QRST angles (peak and mean) differed significantly based on sex, age, and race. Sex differences attenuated with increasing age. Men tended to have larger SVG magnitude (60.4 [46.1-77.8] vs. 52.5 [41.3-65.8] mv*ms, p < .0001) and elevation, and more anterior/negative SVG azimuth (-14.8 [-25.1 to -4.3] vs. 1.3 [-9.8 to 10.5] deg, p < .0001) compared to women. Men also had wider QRST angles. Observed ranges varied significantly with BMI and HR. SVG and QRST angle measurements were robust to different filtering bandwidths and moderate fiducial point annotation errors, but were heavily affected by changes in baseline correction. CONCLUSIONS: Age, sex, race, BMI, and HR significantly affect the range of SVG and QRST angles in patients with normal ECGs and no known cardiovascular disease, and should be accounted for in future studies. An online calculator for prediction of these "normal limits" given demographics is provided at https://bivectors.github.io/gehcalc/.

Normal limits of electrocardiogram in Africans and their consequences on the prevalence of left ventricular hypertrophy in hypertensive individuals: Insights from the TAHES study.

AIMS: To determine normal limits for major ECG variables, and the electrocardiographic impact of hypertension, in a rural sub-Saharan African setting. METHODS: This cross-sectional study included adults aged ≥25 years from Tanvè Health Study (TAHES) cohort. ECG were recorded at rest at 25 mm/s using a standard 12­lead device. Wave amplitudes and durations were measured. Corrected QT interval (QTc) was calculated using Bazett's formula. Sokolow-Lyon, Cornell and Peguero-Lo Presti criteria were determined to assess left ventricular hypertrophy (LVH). RESULTS: ECG was recorded among 997 out of 1407 TAHES participants. After exclusion of subjects with hypertension or diabetes, normal limits, defined as the 2nd and 98th percentiles, were evaluated in 622 healthy participants (median: 37 years; 60.1% women). The following limits were established in men (women): heart rate: 50 to 100 (55 to 102) beats/min, P wave duration: 80 to 120 (80 to 120) ms, PR interval: 120 to 200 (120 to 200) ms, QTc: 315 to 470 (323 to 465) ms, QRS duration: 50 to 120 (50 to 110) ms. Upper limits (in millimeter) for the Sokolow-Lyon, Cornell and Peguero-Lo Presti for men (women) were 47 (38), 30 (22) and 39 (30), respectively, all above current reference limits. The prevalence of LVH in hypertensive subjects according to these criteria were lower than those estimated according to current LVH criteria. CONCLUSION: The normal limits of ECG variables determined in this African population differ from those in Caucasians, indicating that ethnicity must be considered in ECG interpretation.

Normal limits of the electrocardiogram in Angolans.

INTRODUCTION: Studies on the normal electrocardiogram limits in African populations are limited, especially in sub-Saharan Africa. There is no literature describing normal ECG limits in Angolans. OBJECTIVES: The aim of this study is to establish the normal ECG limits for adult Angolans, without established heart disease, stratified by gender and age. METHODS: A cross-sectional study was performed, involving 2179 participants from a population in northern Angola, without established heart disease, aged between 15 and 74 years. A 12­lead ECG and a rhythm strip were recorded for all participants and analysed and processed by the University of Glasgow software and encoded by the Minnesota Code. The normal range of the electrocardiographic parameters were established as the 2nd and 98th percentiles of the measurement distribution per age group and gender. Mann-Whitney and Kruskal-Wallis tests were used for two independent groups and Bonferroni adjustments were used for multiple testing. GAMLSS models were used to obtain the continuous age-dependent percentile curves. RESULTS: The normal range of the ECG differed between men and women: heart rate 49 to 100 bpm vs. 55 to 108 bpm, P wave duration 81 to 130 ms vs. 84 to 130 ms, PR interval 119 to 210 ms vs. 120 to 202 ms, QRS duration 74 to 110 ms vs. 70 to 104 ms, QT interval 324 to 441 ms vs. 314 and 438 ms, P-wave axis - 29 to 850 vs. -18 to 810, QRS-wave axis - 13 to 850 vs. -180 and 820, T-wave axis 0 to 720 vs. -8 to 730, Sokolow-Lyon index 2.13 to 6.21 mV vs. 1.60 to 4.87 mV, Cornell index 0.17 to 6.24 mV vs. 0.14 mV to 4.35 mV. CONCLUSIONS: The values described for the electrocardiographic measurements above can act as a reference framework for Angolan adults without established heart disease. Our study suggests that the normal range of most ECG parameters vary according to age and sex and the ECG diagnostic criteria must therefore be specific for these demographic measures.

Sex- and Age-Related Reference Values in Cardiology, with Annotations and Guidelines for Interpretation.

The definition of "abnormal" in clinical sciences is often based on so-called reference values which point to a range that experts by some sort of consensus consider as normal when looking at biological variables. Such a level is commonly calculated by taking (twice) the standard deviation from the mean, or considering certain percentiles. The suspicion or even confirmation of a disease is then established by demonstrating that the value measured exceeds the upper or lower reference value. As is often the case, the measurement accuracy may depend on the conditions and specific method employed to collect and analyze data. This implies that, for example, data assessed by 2D echocardiography possibly differ from those obtained by MRI and therefore require modality-specific reference values. In this review we summarize reference values for the electrocardiogram, cardiac compartmental volumes, and arterial vessel size in males and females for various age groups. These values may further depend on other variables such as body size, physical training status, and ethnicity. Additional variables relevant for cardiology such as those referring to the microcirculation and biomarkers are only mentioned with reference to the pertinent literature. In general, the sex- and age-specific differences observed are often remarkable and warrant consideration in clinical practice and basic biomedical sciences.

The value of local normal limits in quantitative Thallium-201 CZT MPI SPECT.

BACKGROUND: Considering the distinctive characteristics of CZT detectors, automatic quantification of ischemia using normal limits included with software package may deliver suboptimal results for CAD detection. The present study aims to evaluate the benefits of creating normal limits specific to a local population and laboratory protocol. METHODS AND RESULTS: Two groups were selected from patients who had undergone a CZT MPI. Normal limits were generated with the QPS application based on the population with low likelihood of CAD. Using the vendor-supplied and the population-specific normal limits i-TPD and vessel-specific SDS results obtained for patients who had subsequently undergone coronary angiography were compared with coronary angiography data. A weak correlation was observed for low i-TPD (stress TPD minus rest TPD) and SDS values. Both databases gave similar values for the area under the ROC curve concerning i-TPD (0.75 to 0.74) and SDS results (0.72 to 0.75 for the LAD, 0.62 to 0.64 for the LCx, and 0.63 to 0.67 for the RCA). Sensitivity (60%), specificity (78%), and predictive positive (84%) and negative (52%) values were also similar with a diagnostic and prognostic threshold value. CONCLUSION: The use of a population-specific created database did not influence the diagnostic value of thallium-201 MPI QPS results using a CZT camera.

Normal values of urine total protein- and albumin-to-creatinine ratios in term newborns.

BACKGROUND: It is important to have an accurate assessment of urinary protein when glomerulopathy or kidney injury is suspected. Currently available normal values for the neonate population have limited value, in part because they are based on small populations and obsolete creatinine assays. We have performed a prospective study with the aim to update the normal upper values of the urinary total protein-to-creatinine and albumin-to-creatinine ratios in term newborns. METHODS: Urine samples were collected from 277 healthy, full-term newborns within the first 48 hours (D0-1) and between 72 and 120 h of life (D3-4). Total protein, albumin, creatinine and osmolality were measured and the upper limit of normal (upper-limit) values determined. RESULTS: At D0-1 and D3-4, the upper-limit values for the total protein-to-creatinine ratio were 1431 and 1205 mg/g (162 and 136 g/mol) and those for the albumin-to-creatinine ratio were 746 and 301 mg/g (84 and 34 g/mol), respectively. The upper-limit values were significantly higher at D0-1 than at D3-4 only for the albumin-to-creatinine ratio. CONCLUSION: This study determined the upper limit of normal values for urinary total protein-to-creatinine and albumin-to-creatinine ratios in the largest population of newborns studied to date. These values can therefore be considered as the most clinically relevant data currently available for the detection and diagnosis of glomerular injury in daily clinical practice in this population.

[Heidelberg retinal tomography of the optic disc in the early diagnosis of glaucoma]. / Geidel'bergskaia retinotomografiia diska zritel'nogo nerva v rannei diagnostike glaukomy.

AIM: To analyze anatomical and topographic optic disc parameters with account to the disc area in glaucoma suspects. MATERIAL AND METHODS: The study included 302 patients (408 eyes) aged 25 to 76 years (the mean age of 50.5±12.5 years); men and women roughly equal in number. The eyes were divided into 8 groups depending on the disc area, which ranged from 0.89 to 3.5 mm2. With HRT, 11 global and sector optic disc parameters were examined, 4 of which (disc area, rim area, cup/disc ratio, mean RNFL thickness) are presented in this paper. RESULTS: The study revealed a great variability of disc area values as well as individual morphometric features of the examined optic discs. We have also established high statistical significance of the difference between the above-listed optic disc parameters, both global and sectoral, in groups with different disc areas with the exception of the mean RNFL thickness. CONCLUSION: For early glaucoma detection with HRT, it is advisable to consider the individual area-dependent anatomical and topographic features of the optic disc.

Can psychosine and galactocerebrosidase activity predict early-infantile Krabbe's disease presymptomatically?

Krabbe's disease (KD) is a fatal neurodegenerative disorder, with the early-infantile form (EIKD) defined by onset of symptoms before age 6 months. Early and highly accurate identification of EIKD is required to maximize benefits of hematopoietic stem cell transplantation treatment. This study investigates the potential for accurate prediction of EIKD based on a novel newborn screening (NBS) tool developed from two biomarkers, galactocerebrosidase (GALC) enzyme activity and galactosylsphingosine concentration (psychosine [PSY]). Normative information about PSY and GALC, derived from distinct samples of normal newborns, was used to develop the novel diagnostic tool. Bivariate normal limits (BVNL) were constructed, assuming a multivariate normal distribution of natural logarithms of GALC and PSY of normal newborns. The (lnGALC, lnPSY) points for newborns in various "abnormal groups," including one group of infants who subsequently suffered EIKD, were plotted on a graph of BVNL. The points for all EIKD patients fell outside of BVNL (100% sensitivity). In a simulation study to compare the false-positive rate of existing univariate methods of diagnosis with our new BVNL-based method, we generated 100 million normal newborn data points. All fell within BVNL (i.e., zero false positives), whereas 5,682 false positives were observed when applying a two-tiered univariate method of the type suggested in the literature. These results suggest that (lnGALC, lnPSY) BVNLs will allow highly accurate prediction of EIKD, whereas two-tiered univariate approaches will not. Redevelopment of the BVNL based on GALCs and PSYs measured on a common large sample of normal newborns is required for NBS use. © 2016 Wiley Periodicals, Inc.

Normal limits of the electrocardiogram in Indians.

AIMS: The objective of the study was to develop normal limits of the ECG in an apparently healthy population of South Asians living in India. METHODS: Three centres contributed to recording 12 lead ECGs on identical digital electrocardiographs. Apparently healthy volunteers were recruited and ECGs were first transferred to a local database and then to Glasgow where all ECGs were analysed by the same University of Glasgow ECG Interpretation Program. RESULTS: A total of 963 individuals were recruited into the study (30.4% female) with an age range of 18-83 years. QRS duration was longer in males than females, QT interval was longer in females than males, and QRS voltages in general were higher in males than females and in younger compared to older individuals. CONCLUSION: Findings in general paralleled those in other populations and suggested that criteria for a white Caucasian population could be applied to a South Asian Indian population.

Normal values of the electrocardiogram for ages 16-90 years.

INTRODUCTION: To establish an up-to-date and comprehensive set of normal values for the clinically current measurements in the adult ECG, covering all ages for both sexes. METHODS: The study population included 13,354 individuals, taken from four population studies in The Netherlands, ranging in age from 16 to 90 years (55% men) and cardiologically healthy by commonly accepted criteria. Standard 12-lead ECGs were available for all participants. The ECGs were processed by a well-validated computer program. Normal limits were taken as the 2nd and 98th percentiles of the measurement distribution per age group. RESULTS: Our study corroborates many findings of previous studies, but also provides more differentiated results, in particular for the older age groups. Age trends were apparent for the QTc interval, QRS axis, and indices of left ventricular hypertrophy. Amplitudes in the left precordial leads showed a substantial increase in the older age groups for women, but not for men. Sex-dependent differences were apparent for most ECG parameters. All results are available on the Website www.normalecg.org, both in tabular and in graphical format. CONCLUSIONS: We determined age- and sex-dependent normal values of the adult ECG. Our study distinguishes itself from other studies by the large size of the study population, comprising both sexes, the broad range of ages, and the exhaustive set of measurements. Our results emphasize that most diagnostic ECG criteria should be age- and sex-specific.

Racial differences in the ECG--selected aspects.

INTRODUCTION: Racial differences in the ECG have been known about for many years but there has been no significant comparison of large population groups. This study set out to remedy this shortcoming. METHODS: Digital ECG data were available for four population samples gathered in Scotland, Taiwan, Nigeria and India. All ECGs were recorded in the different countries and processed centrally by the University of Glasgow ECG Analysis Program. Measurements were analysed statistically to look for significant differences. RESULTS: There were 4223 individuals in the study (2559 males and 1664 females). In general terms, findings such as QRS duration being longer in males than females applied to all four races. More specifically, QRS voltages were higher in young black males compared to others, while ST amplitudes, as in V2, were higher in Chinese and Nigerian males than in Caucasians. CONCLUSION: Race requires to be taken into account to enhance automated interpretation of the ECG.

Ovarian Morphology in Non-Hirsute, Normo-Androgenic, Eumenorrheic Premenopausal Women from a Multi-Ethnic Unselected Siberian Population.

Polycystic ovary syndrome (PCOS) is a highly prevalent disorder in women, and its diagnosis rests on three principal features: ovulatory/menstrual dysfunction, clinical and/or biochemical hyperandrogenism, and polycystic ovarian morphology (PCOM). Currently, data on age- and ethnicity-dependent features of PCOM remain insufficient. We aimed to estimate ethnicity- and age-dependent differences in ovarian volume (OV) and follicle number per ovary (FNPO) in a healthy, medically unbiased population of Caucasian and Asian premenopausal women, who participated in the cross-sectional Eastern Siberia PCOS epidemiology and phenotype (ESPEP) study (ClinicalTrials.gov ID: NCT05194384) in 2016-2019. The study population consisted of 408 non-hirsute, normo-androgenic, eumenorrheic premenopausal women aged 18-44 years. All participants underwent a uniform evaluation including a review of their medical history and a physical examination, blood sampling, and pelvic ultrasonography. The statistical analysis included non-parametric tests and the estimation of the upper normal limits (UNLs) by 98th percentiles for OV and FNPO. In the total study population, the upper OV percentiles did not differ by ethnicity or age group. By contrast, the UNL of FNPO was higher in Caucasian women than in Asian women, and women aged <35 years demonstrated a higher UNL of FNPO compared to older women. In summary, these data suggest that the estimation of FNPO, but not OV, should take into account the ethnicity and age of the individual in estimating the presence of PCOM.

A Roadmap for Potential Improvement of Newborn Screening for Inherited Metabolic Diseases Following Recent Developments and Successful Applications of Bivariate Normal Limits for Pre-Symptomatic Detection of MPS I, Pompe Disease, and Krabbe Disease.

The mucopolysaccharidoses (MPS), Pompe Disease (PD), and Krabbe disease (KD) are inherited conditions known as lysosomal storage disorders (LSDs) The resulting enzyme deficiencies give rise to progressive symptoms. The United States Department of Health and Human Services' Recommended Uniform Screening Panel (RUSP) suggests LSDs for inclusion in state universal newborn screening (NBS) programs and has identified screening deficiencies in MPS I, KD, and PD NBS programs. MPS I NBS programs utilize newborn dried blood spots and assay alpha L-iduronidase (IDUA) enzyme to screen for potential cases. Glycosaminoglycans (GAGs) offer potential as a confirmatory test. KD NBS programs utilize galactocerebrosidase (GaLC) as an initial test, with psychosine (PSY) activity increasingly used as a confirmatory test for predicting onset of Krabbe disease, though with an excessive false positive rate. PD is marked by a deficiency in acid α-glucosidase (GAA), causing increased glycogen, creatine (CRE), and other biomarkers. Bivariate normal limit (BVNL) methods have been applied to GaLC and PSY activity to produce a NBS tool for KD, and more recently, to IDUA and GAG activity to develop a NBS tool for MPS I. A BVNL tool based on GAA and CRE is in development for infantile PD diagnosis. Early infantile KD, MPS I, and PD cases were pre-symptomatically identified by BVNL-based NBS tools. This article reviews these developments, discusses how they address screening deficiencies identified by the RUSP and may improve NBS more generally.

Establishing Normative Values to Determine the Prevalence of Biochemical Hyperandrogenism in Premenopausal Women of Different Ethnicities from Eastern Siberia.

Androgen assessment is a key element for diagnosing polycystic ovary syndrome (PCOS), and defining a "normal" level of circulating androgens is critical for epidemiological studies. We determined the upper normal limits (UNLs) for androgens in a population-based group of premenopausal "healthy control" women, overall and by ethnicity (Caucasian and Asian), in the cross-sectional Eastern Siberia PCOS Epidemiology and Phenotype (ESPEP) Study (ClinicalTrials.gov ID: NCT05194384) conducted in 2016-2019. Overall, we identified a "healthy control" group consisting of 143 healthy premenopausal women without menstrual dysfunction, hirsutism, polycystic ovaries, or medical disorders. We analyzed serum total testosterone (TT) by using liquid chromatography with tandem mass spectrometry (LC-MS/MS), and DHEAS, sex-hormone-binding globulin (SHBG), TSH, prolactin, and 17-hydroxyprogesterone (17OHP) were assessed with an enzyme-linked immunosorbent assay (ELISA). The UNLs for the entire population for the TT, free androgen index (FAI), and DHEAS were determined as the 98th percentiles in healthy controls as follows: 67.3 (95% confidence interval (CI): 48.1, 76.5) ng/dl, 5.4 (3.5, 14.0), and 355 (289, 371) µg/dl, respectively. The study results demonstrated that the UNLs for TT and FAI varied by ethnicity, whereas the DHEAS UNLs were comparable in the ethnicities studied.

Cerebrospinal fluid opening pressure in clinical practice - a prospective study.

BACKGROUND: Measurement of CSF opening pressure (CSFOP) is valuable and much used in the investigation of several neurological conditions. However, there are different opinions regarding reference values and influence of age, gender and body mass index (BMI). We have, in a previous study, noted possible differences in CSFOP between gender and age groups. Here the aim was to collect information regarding normal distribution of CSFOP in an out-patient sample and also include BMI. METHODS: We collected CSFOP from a lumbar puncture, following a standardized procedure, performed in an ordinary neurological out-patient sample. Age, gender and BMI was also registered. Descriptive statistics and linear regression was used. RESULTS: 339 patients with a normal distribution of age and BMI were included consecutively (60% females). We found a mean CSFOP of 17.5 H2O (range 4.0-30.0). In multivariable linear regression, age, gender and BMI all independently affected CSFOP. Male gender (ß = 1.5, p = 0.002), lower age (ß = - 0.095, p < 0.001) and higher BMI (ß = 0.42, p < 0.001) were all associated with higher CSFOP. CONCLUSION: Using two standard deviations, we provide suggestions for CSFOP limits with respect to gender, age and BMI. Our results suggest that CSFOP cut-offs for pathological intracranial hypertension should be raised with these factors taken into consideration. As a "rule-of-thumb" we suggest the following cut-offs: for males < 30 cm H2O (< 25 if over age 70), and for females < 25 cm H2O (27.5 if over 30 BMI). A diagnosis of intracranial hypertension should not be given without such considerations.

Normal Values of QT Variability in 10-s Electrocardiograms for all Ages.

Aims: QT variability is a promising electrocardiographic marker. It has been studied as a screening tool for coronary artery disease and left ventricular hypertrophy, and increased QT variability is a known risk factor for sudden cardiac death. Considering that comprehensive normal values for QT variability were lacking, we set out to establish these in standard 10-s electrocardiograms (ECGs) covering both sexes and all ages. Methods: Ten-second, 12-lead ECGs were provided by five Dutch population studies (Pediatric Normal ECG Study, Leiden University Einthoven Science Project, Prevention of Renal and Vascular End-stage Disease Study, Utrecht Health Project, Rotterdam Study). ECGs were recorded digitally and processed by well-validated analysis software. We selected cardiologically healthy participants, 46% being women. Ages ranged from 11 days to 91 years. After quality control, 13,828 ECGs were available. We assessed three markers: standard deviation of QT intervals (SDqt), short-term QT variability (STVqt), and QT variability index (QTVI). Results: For SDqt and STVqt, the median and the lower limit of normal remained stable with age. The upper limit of normal declined until around age 45, and increased strongly in the elderly, notably so in women. This implies that a subset of the population, small enough not to have appreciable effect on the median, shows a high degree of QT variability with a possible risk of arrhythmias or worse, especially in women. Otherwise, sex differences were negligible in all three measurements. For QTVI, median, and normal limits decreased until age 20, and steadily went up afterwards except for the lower limit of normal, which flattens off after age 65. Conclusion: We report the first set of normal values for QT variability based on 10-s ECGs, for all ages and both sexes.

Precordial electrode placement in women.

BACKGROUND: Precordial ECG electrode positioning was standardised in the early 1940s. However, it has been customary for the V3 to V6 electrodes to be placed under the left breast in women rather than in the correct anatomical positions relating to the 4th and 5th interspaces. For this reason, a comparison between the two approaches to chest electrode positioning in women was undertaken. METHODS: In total 84 women were recruited and ECGs recorded with electrodes in the correct anatomical position and also in the more commonly used positions under the breast. As a separate study, 299 healthy women were recruited to study normal limits of leads V3 to V6 recorded with electrodes in the correct anatomical positions and compare them with published normal limits with electrodes in the more commonly used locations. RESULTS: It was shown that there was less variability with electrodes in the correct anatomical positions and that there were significant differences between the new limits of normality compared with the old established limits. CONCLUSION: Expansion of the database and further analysis of the data is required to make a definitive recommendation with respect to precordial electrode placement in women.

Ascending aorta diameters measured by echocardiography using both leading edge-to-leading edge and inner edge-to-inner edge conventions in healthy volunteers.

AIMS: Reference ranges of ascending aorta diameters (AAoD) for two-dimensional echocardiography (2DE) using inner edge (IE) convention are lacking, preventing the comparison of AAoD measurements by 2DE with those obtained by other imaging modalities. METHODS AND RESULTS: We used harmonic imaging 2DE to prospectively study 218 healthy volunteers (56% women, 42 ± 15 years, 18-80 years). Measurements were performed at the level of aortic root (AoR), sinotubular junction (STJ), and proximal tubular portion (TAo, 1 cm from the STJ) using both leading edge (LE) and IE conventions at end-diastole and end-systole. Feasibility of AAoD measurements between end-diastole and end-systole was similar at AoR and STJ levels, but it was significantly different at TAo level (82 vs. 96%, respectively, P < 0.0001). Ascending aorta diameters indexed to height were larger in men than in women (P < 0.0001). After adjusting for the effect of gender, only age and body surface area (BSA) were independent predictors of AAoD at multivariable analysis. Average end-diastolic AoR, STJ, and TAo diameters measured using IE convention were similar between genders (17 ± 2, 15 ± 2, and 15 ± 2 mm/m(2), respectively). Corresponding AAoD measured using the LE convention were 18 ± 2, 16 ± 2, and 17 ± 4 mm/m(2), respectively. On average, the end-systolic AAoD measured using LE were 2 mm larger than those performed using IE or at end-diastole. Mean aortic wall thickness was 2.4 ± 0.8 mm. CONCLUSION: End-diastolic AAoD measured using IE were significantly smaller than those obtained either using LE convention or at end-systole. Gender-specific reference values for AAoD indexed for BSA should be used to identify ascending aorta pathology.