(Hypertension. 1995;25:242-249.)
© 1995 American Heart Association, Inc.
Articles |
Gender Differences and the Electrocardiogram in Left Ventricular Hypertrophy
From the Division of Cardiology, Department of Medicine, The New York Hospital–Cornell Medical Center (NY).
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Abstract We examined the relations of gender differences in electrocardiographic (ECG) voltages and QRS duration to differences in cardiac dimensions and body size between men and women and gender differences in test performance of ECG criteria for the detection of echocardiographic left ventricular hypertrophy in 389 subjects (112 women and 277 men). ECG voltage-duration products were calculated as the product of QRS duration and voltages. Among subjects with normal left ventricular mass and also among subjects with left ventricular hypertrophy, men had longer QRS duration, higher Cornell voltage, higher 12-lead sum of QRS voltage, and higher Cornell and 12-lead voltage-duration products than did women. Significant gender differences in QRS duration, Cornell voltage, the 12-lead sum of voltage and their voltage-duration products remained after adjusting for the greater left ventricular mass, height, and weight in men than women. Comparison of areas under receiver operating characteristic curves using gender-specific criteria demonstrated higher performance of QRS duration, Cornell voltage, the 12-lead sum of QRS voltage, and the respective voltage-duration products for the identification of left ventricular hypertrophy in men than women. Thus, gender differences in body size and left ventricular mass do not completely account for gender differences in QRS duration and voltage measurements, and ECG criteria for left ventricular hypertrophy have lower accuracy in women even when gender differences in partition value selection are taken into account. These findings indicate a need for new, more accurate, and gender-specific ECG criteria for the detection of hypertrophy and suggest that factors other than left ventricular dimensions and body size may play a role in the observed differences in QRS voltages and durations between men and women.
Key Words: electrocardiography • hypertrophy, left ventricular • gender
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Introduction |
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Standard 12-lead electrocardiographic (ECG) measurements indicate that men have significantly longer QRS durations1 2 3 4 5 6 and greater ECG voltages4 5 6 7 8 9 10 than do women. Although these differences in ECG findings have been attributed to gender differences in body size and left ventricular (LV) mass,3 4 5 it remains uncertain whether gender differences in QRS durations and voltages can be fully attributed to differences in cardiac dimensions and body size between men and women and whether adjustment for these variables would make ECG identification of LV hypertrophy (LVH) equally accurate in men and women.
Among ECG criteria used to detect LVH,9 10 11 12 13 14 15 16 17 several are routinely adjusted for gender,10 11 12 13 14 but only limited information is available about the relative performance of ECG criteria in men and women.17 18 19 20 Therefore, we conducted the present study to examine the relation of gender differences in QRS duration and voltages to differences in body size and cardiac dimensions between women and men and to systematically assess the relative performance of ECG criteria for the identification of LVH in women and men.
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Methods |
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Study Population
Standard 12-lead ECGs were acquired in 389 subjects who underwent echocardiography at The New York Hospital–Cornell Medical Center as part of several ongoing, longitudinal studies. Group 1 consisted of 273 normotensive or mildly hypertensive subjects (208 men and 65 women; mean age, 51±12 [SD] years) with normal LV mass indexed to body surface area as will be defined below. Group 2 consisted of 116 subjects with LVH (69 men and 47 women; mean age, 53±15 years): 48 mildly hypertensive or normotensive subjects and 68 subjects with chronic regurgitant valvular heart disease. Because of the absence of any subjects with left or right bundle branch block in group 1, subjects with bundle branch blocks were also excluded from group 2. All subjects gave informed consent to participation in the study, which was performed in accordance with protocols approved by the Committee on Human Rights in Research of Cornell University Medical College.
Electrocardiography
Standard 12-lead ECGs were recorded at 25 mm/s and 1.0 mV/cm
standardization with equipment whose frequency response characteristics
met recommendations of the American Heart Association21
(Marquette Electronics Inc). All ECGs were digitized at 250 or 500 Hz,
and all measurements were performed by computer algorithm with visual
verification by a single investigator who had no knowledge of
calculated LV mass; QRS duration was measured by computer to the
nearest 2 milliseconds, and QRS amplitudes were measured to the nearest
microvolt (100 µV=0.1 mV=1.0 mm) by computer from median complexes
derived from 10-second samples.
Several widely used ECG criteria for the detection of LVH were examined, including QRS duration20 ; the R wave amplitude in lead aVL; Sokolow-Lyon voltage (sum of the amplitudes of the S wave in lead V1 and the R wave in lead V5 or V6)16 ; Cornell voltage (sum of the amplitudes of the R wave in lead aVL and the S wave in lead V3, not adjusted for gender)11 20 ; and the sum of QRS voltage in all 12 leads.9 A voltage-duration product was calculated for Sokolow-Lyon voltage (the Sokolow-Lyon product), Cornell voltage (the Cornell product), and for the 12-lead sum of voltage (the 12-lead product) as the product of QRS duration and voltage.20 Because performance of Cornell voltage has recently been shown to improve when adjusted for age and obesity,14 gender-specific–adjusted Cornell voltage calculated according to the regression equations of Norman et al14 was related to LV mass indexed for height and body surface area.
Echocardiography
All subjects underwent standard M-mode and
two-dimensional echocardiography performed by a research technician
using commercially available echocardiographs equipped with 2.5- and
3.5-MHz imaging transducers. LV dimensions were obtained from
two-dimensionally guided M-mode tracings according to the
recommendations of the American Society of
Echocardiography.22 Measurements were performed on
multiple cardiac cycles by use of a digitizing tablet and were
averaged. If M-mode tracings were technically inadequate, LV wall
thicknesses and internal dimensions were measured from the
two-dimensional study using the method recommended by the American
Society of Echocardiography.23 LV mass was calculated
according to an anatomically validated formula,24 and LVH
was considered present when the LV mass index was greater than 110
g/m2 in women or 125 g/m2 in men, partition
values based on the distribution of values in employed normotensive and
hypertensive adults25 and subsequently shown to be related
to prognosis.26 27
Data Analysis and Statistical Methods
Mean values and standard deviations are reported for each
variable by group. Comparisons of mean demographic and
echocardiographic values between men and women were performed using
Student's t test; simple proportions were compared using
2 analysis. Mean values of ECG criteria in
men and women were compared after first adjusting for the presence or
absence of LVH using two-way ANOVA that included an interaction term
between gender and LVH. Significance of the interaction term and gender
simple main effects were assessed for each comparison. Gender
differences were further examined after dividing ECG criteria by LV
mass and the ratio of LV mass to body surface area to derive ratios of
QRS durations, QRS voltages, and QRS voltage-duration products per unit
of LV mass and LV mass index. Because standard deviations were found to
vary significantly between groups, the raw data were logarithmically
transformed before statistical testing by application of two-way ANOVA.
However, all data shown in the tables reflect the nontransformed
values. Mean values of ECG criteria were also compared using ANCOVA to
adjust for baseline differences between men and women in height,
weight, and LV mass. The strength of the relation between ECG variables
and LV mass index was assessed by Pearson correlation coefficients.
Differences in correlation coefficients between men and women were
compared statistically by two-tailed tests after application of
Fisher's Z transformation. Gender independence of ECG variables was
further assessed using stepwise multiple linear regression analyses
that included height, weight, LV mass, age, gender, and gender
interaction terms. The probability value for variables to enter and
remain in the model was .05.
Because QRS duration, voltage, and voltage-duration criteria were found to differ significantly between men and women and because the sensitivity and specificity of a test depend on the partition values chosen for test positivity, receiver operating characteristic curve analysis was used to compare test accuracy of ECG criteria using gender-specific criteria. Receiver operating characteristic curves compare the sensitivity and specificity of different tests over a wide range of possible partition values and can be used to compare differences in test performance between two different populations independent of empirically derived criteria, with greater area under the performance curve of a population indicative of superior test performance.28 Receiver operating characteristic curves were compared statistically using a univariate z score test of the difference between the areas under two performance curves.28 For all tests, a value of P<.05 was required for rejection of the null hypothesis.
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Results |
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Relation of Clinical and Echocardiographic Variables to Gender
Gender differences in clinical and echocardiographic variables in relation to the presence or absence of LVH are examined in Table 1. Men and women with and without LVH were similar with respect to age, but men had a significantly higher mean body surface area, greater LV wall thickness, greater LV internal dimension during diastole, higher LV mass, and higher indexed LV mass. Mean body mass index was similar in men and women without LVH but was significantly greater in men with hypertrophy. Gender-specific indexed LV mass partitions showed a higher prevalence of LVH in women than men (42% versus 25%).
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Relation of ECG Variables to Gender
The univariate linear correlations of ECG variables with indexed
LV mass in men and women are shown in Table 2. Only
modest correlations existed between LV mass index and ECG criteria for
LVH in both men and women. However, the correlation with indexed LV
mass was significantly higher in men than women for Sokolow-Lyon
voltage, Cornell voltage, the 12-lead sum of voltage, and for both the
Sokolow-Lyon and Cornell voltage-duration products, with a trend toward
better correlation in men for both QRS duration and the 12-lead
product. Weaker correlations were observed between unindexed LV mass
and all variables except QRS duration in both women and men. In
addition, correlations with LV mass index were higher when each of the
simple voltage criteria was multiplied by QRS duration in both men and
women. Of note, male gender was a highly significant correlate of
higher LV mass and predictor of the presence of echocardiographic LVH
in stepwise multivariate regression analyses that also included
demographic variables and each ECG criterion.
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Mean values of QRS durations, QRS voltages, and QRS voltage-duration products in women and men with or without LVH are presented in Table 3. Men both with and without LVH had longer QRS duration, greater R wave amplitude in lead aVL, higher Cornell voltage, and higher 12-lead sum of voltage than did women, but there was no statistical difference in Sokolow-Lyon voltage between men and women. As a consequence of the longer QRS duration and higher voltages, each of the voltage-duration products was greater in men than women (Table 3).
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Because men and women differed significantly with respect to LV dimensions and body size (Table 1), the relation of mean values of ECG criteria to gender was examined further after dividing ECG measurements by LV mass and LV mass index. When measured variables were individually normalized for LV mass only, QRS duration, Cornell voltage, the Sokolow-Lyon product, and the 12-lead voltage and product all became significantly greater per gram of LV mass in women than men. Differences in ECG measures between men and women became less evident and variable in direction when normalization was based on LV mass indexed for body surface area, but both the Cornell product and the 12-lead product normalized to LV mass index were higher in men than women after adjusting for the greater body surface area. The relation of ECG measures to gender became more consistent after ECG criteria were adjusted for LV mass, height, and weight using ANCOVA (Table 4). Measured QRS duration, the R wave amplitude in lead aVL, Cornell and 12-lead QRS voltages, and the three QRS voltage-duration products were greater in men than women after ECG measurements were adjusted for baseline gender differences in body size and LV mass. Furthermore, stepwise multiple linear regression analyses incorporating age, height, weight, LV mass, and gender further demonstrated that Cornell and 12-lead voltages and voltage-duration products differed between men and women independent of gender differences in body size and LV dimensions (Table 5).
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ECG Identification of LVH
Because QRS duration and voltages and, as a consequence,
the voltage-duration products were significantly greater in men than
women even after adjustment for the presence or absence of LVH, test
performance of these criteria for the detection of LVH cannot be
accurately compared in men and women using the same partition values.
Accordingly, the relation of test performance to gender was compared,
using gender-specific echocardiographic criteria to identify LVH, by
analysis of separate receiver operating characteristic curves for
each gender. The clinically relevant portions of these curves with
specificities from 80% to 100% are shown in Figs 1 through 5.
Independent of test partition value selection, test performance of all
criteria for the identification of LVH was significantly better in men
than women, with higher areas under the receiver operating
characteristic curves in men for QRS duration (0.83 versus 0.78,
P<.05) (Fig 1), Sokolow-Lyon voltage (0.86 versus 0.76,
P<.01) and Sokolow-Lyon product (0.90 versus 0.83,
P<.05) (Fig 2), Cornell voltage (0.81 versus 0.72,
P<.05) and Cornell product (0.83 versus 0.76,
P<.05) (Fig 3), and the 12-lead sum of voltage (0.86 versus
0.80, P<.05) and the 12-lead product (0.89 versus 0.84,
P<.05) (Fig 4). After adjustment of Cornell voltage for age
and body mass index, overall performance remained significantly greater
in men than women for LVH defined by the ratio of LV mass to body
surface area (0.73 versus 0.55, P<.01) (Fig 5) or by the
ratio of LV mass to height using partitions of 143 g/m in men and 102
g/m in women14 (0.75 versus 0.65, P<.05).
Overall test performance of each of the voltage criteria was
significantly improved by creation of a voltage-duration product in
both men and women.
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Higher test performance in men was not a consequence of more severe LVH in men than women: the mean ratio of LV mass index in subjects with hypertrophy to the gender-specific partitions for LVH (125 g/m2 in men and 110 g/m2 in women) was nearly identical in men and women (1.36±0.30 versus 1.39±0.31, P=NS). Gender differences in performance were also not a result of the lower LV mass index values used to define LVH in women, with similar results found when LVH was classified in all subjects, independent of gender, according to an indexed LV mass partition of 125 g/m2. In addition, lower overall performance in women was not a consequence of the definition of LVH, with similar gender differences in test performance observed for the voltage-duration products when LVH was defined by LV mass indexed to height14 or height to the 2.7 power29 or by simple LV mass partitions30 (Table 6).
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Discussion |
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These data demonstrate that gender differences in body size, obesity, and LV mass do not completely account for gender differences in QRS duration, QRS voltages, and QRS voltage-duration products and that all ECG criteria have lower accuracy for the detection of LVH in women even when gender differences in partition value selection are taken into account. These findings indicate a need for the development of new, more accurate, and gender-specific ECG criteria for the detection of LVH and suggest that factors other than LV dimensions and body size may play a role in the observed differences in QRS voltages and duration between men and women.
Relation of QRS Duration and Voltage to Gender
Previous studies that found significant gender differences in QRS
duration1 2 3 4 5 6 and voltages4 5 6 7 8 9 10 attributed these
differences in part to the relatively larger body and heart sizes in
men compared with women3 4 5 ; however, none of these studies
examined the relation of ECG measures to heart or body size separately
in women and men. The present study demonstrates that, although
lower QRS voltages and shorter QRS durations in women are in part
accounted for by gender differences in height, weight, and LV mass,
some differences in ECG measurements persist even after adjustment for
gender differences in cardiac dimensions and body size. Although
increasing age in adults has been associated with decreasing QRS
amplitudes,1 2 17 men and women in the present study
were of similar ages. Accordingly, other factors must play a role in
these differences.
Decreased QRS amplitudes in women may be explained in part by the increased spatial separation of myocardium from precordial electrodes attributable to breast tissue.31 Increased chest wall thickness has also been associated with false-negative Sokolow-Lyon voltages in both men and women,32 and increased QRS amplitude has been found after mastectomy.33 However, the persistent gender differences in R wave amplitude in limb lead aVL after adjustment for differences in body size and LV mass (Table 4) suggest that breast tissue attenuation alone does not account for the observed differences. Although obesity has been associated with a relative decrease in QRS amplitude,14 17 32 differences in QRS voltages between men and women persisted in the current study even after adjustment for body mass index, a measure of obesity.
Gender differences in lean body mass, which may well account for the differences in LV mass index in healthy men and women,30 may play a significant role in these gender differences in QRS amplitudes. Previous study has demonstrated that lean body mass is approximately 40% higher in men than women and that indexation of LV mass by lean body mass eliminated the sex differences found for LV mass and LV mass indexed for body surface area or height.30 In this context, it is intriguing to note that voltage-duration products were 35% to 41% higher in men than women with LVH, a difference that remained significant even after adjustment for baseline gender differences in height, weight, and LV mass (Table 4). Similarly, 18% to 22% greater values were seen in men for adjusted limb lead voltages alone, arguing that these differences are not solely due to the effects of increased breast tissue in women.32 33 Further investigation of the relation of QRS measurements to gender differences in lean body mass may be of interest.
Gender Differences in the ECG Identification of LVH
Although the potential need for gender-specific ECG criteria for
the detection of LVH has been recognized for some
time,4 8 10 11 12 13 14 17 18 19 only a few ECG criteria either have
used gender-specific voltage criteria10 11 14 or have
otherwise adjusted for gender.10 11 12 13 The gender-specific
criteria currently available10 11 12 13 14 have improved the
accuracy of the ECG for the detection of LVH in selected
populations,10 11 12 13 14 but the relative performance of ECG
criteria in men and women has not been examined in
detail.10 11 12 13 14 17 18 19 Savage et al19 reported
that women with echocardiographic LV mass index greater than 200
g/m2 were three to four times more likely to have ECG LVH
than men with similar increases in indexed LV mass. However, this
finding is confounded by the fact that this partition value for LV mass
index would tend to identify more severe LVH in women than
men25 and is difficult to interpret because the
sensitivity of ECG criteria for LVH was not discussed. Although both
Levy et al17 and Timmis et al18 found
marginally lower sensitivities for different ECG criteria in women than
men, test specificity was higher in the women, making a direct
comparison of test performance difficult.
The present study demonstrates that the overall accuracy of widely used voltage criteria, QRS duration and the products of QRS voltage and duration, is significantly lower in women than men. These findings are supported by a recent report34 in which the overall performance of Cornell voltage criteria was lower in women than men when receiver operating characteristic curves were compared. In contrast, Norman et al14 demonstrated similar sensitivity for Cornell voltage criteria in men and women at specificities of 85% or greater. Although the differences between our findings and those of Norman et al may reflect population differences in the prevalence, severity, or geometric type of LVH,14 17 these differences could in part reflect the use of "fuzzy" receiver operating characteristic curve analysis to derive sensitivities in their study.
Our findings further suggest that decreased performance of ECG criteria in women may be partially attributable to disproportionately lower QRS voltage and duration in women per gram of LV mass when gender differences in body size, obesity, and cardiac dimensions are taken into account. These differences in performance might be explained by the lower absolute LV mass or LV mass index partition values—derived from population-based cross-sectional studies19 25 29 30 —used to identify LVH in women compared with men. However, similar differences in performance were found even when LVH was classified in all subjects on the basis of a single, gender-independent, LV mass index partition value that has been shown to be related to prognosis,26 27 35 and also when LVH was defined according to other gender-specific or gender-independent partitions drawn from several separate studies (Table 6). These observations and the finding that QRS voltages and duration were higher in men than women after adjustment for the presence or absence of LVH (Table 3) suggest that the indexed LV mass partitions used for population definition do not play a significant role in the lower test performance of ECG criteria in women. Similarly, although increased LVH severity has been associated with improved ECG sensitivity,14 17 there was no apparent difference in LVH severity in the men and women in the present study. However, the current observations and previous findings30 suggest that gender differences in ECG performance for detecting LVH might be reduced or eliminated if LV mass could be routinely indexed to lean body mass.
Obesity has also been suggested to significantly reduce the accuracy of ECG criteria for the detection of LVH14 17 32 because of the attenuating effects of obesity on QRS amplitudes and the association of LVH with obesity.14 17 A recent study demonstrated that adjusting Cornell voltage for both age and obesity increases gender-specific criteria sensitivity for LVH,14 but it did not examine relative test performance separately in men and women. The lower overall performance of Cornell voltage adjusted for age and obesity in women in the present study, even when LVH is based on LV mass indexed for height, together with the lower overall voltages in women compared with men even after adjustment for height and weight (Table 4) indicate that gender differences in test performance persist even after age and obesity are taken into account. In addition, normalization of LV mass for body surface area may not accurately reflect differences in LV mass due to obesity,29 which may be more accurately measured by normalization of LV mass to height to the 2.7 power.29 However, gender differences in QRS duration, QRS voltages, and test performance persisted in the present study even when definitions of LVH based on LV mass indexed to height to the 2.7 power were used.29 Of note, the lower overall accuracy of adjusted Cornell voltage for LVH in the current study when LV mass is indexed to body surface area compared with when LV mass is indexed to height reflects the initial derivation of these criteria using a regression model fitted to LV mass indexed to height.14
Limitations
The lower overall performance of Cornell voltage criteria
relative to the performance of the 12-lead sum and Sokolow-Lyon
criteria in the present study contrasts with previous reports from
our laboratory,10 11 20 which were based on study
populations with high prevalences of concentric rather than eccentric
LVH. This difference is most likely explained by the higher proportion
of subjects with dilated left ventricles and eccentric LVH in the
current study and the relatively lower overall performance of Cornell
criteria found in this particular form of cardiac
enlargement.36 Although the small cell sizes that result
if our population is subdivided by two genders, two patterns of LVH
(eccentric and concentric), and the three clinical conditions
(hypertension, mitral regurgitation, and aortic regurgitation) preclude
meaningful subset analyses at this level of detail, it is important to
note that gender differences in ECG findings were apparent among the
subjects without LVH in whom differences in LV geometric patterns would
not be a major consideration.
Clinical Implications
The increased cardiac morbidity and mortality associated with the
presence of echocardiographically detected
LVH26 27 35 37 38 39 make the accurate and cost-effective
identification of LVH a clinical priority.40 The
present findings provide further support for the need for gender
adjustment of ECG criteria to achieve optimal performance for the
detection of LVH. In particular, the significant differences between
women and men in the QRS voltage-duration products suggest that
gender-specific criteria will also be necessary to optimize the
performance of newer ECG methods based on measurement of the
time-voltage area of the QRS that appear to improve test
performance.20 41
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Footnotes |
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Reprint requests to Peter M. Okin, MD, The New York Hospital–Cornell Medical Center, 525 East 68th St, New York, NY 10021.
Received December 27, 1993; first decision January 27, 1994; accepted October 17, 1994.
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References |
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1. Levy D, Bailey JJ, Garrison RJ, Horton MR, Bak SM, Lyons D, Castelli WP. Electrocardiographic changes with advancing age: a cross-sectional study of the association of age with QRS axis, duration and voltage. J Electrocardiol. 1987;20(suppl):44-47.
2. Chen CY, Chiang BN, Macfarlane PW. Normal limits of the electrocardiogram in a Chinese population. J Electrocardiol. 1989; 22:1-15.
3. Goldberger AL, Bhargava V. QRS duration measurement using high-frequency electrocardiography: applications and limitations of a new technique. Comput Biomed Res. 1982;15:474-484. [Medline] [Order article via Infotrieve]
4.
Simonson E, Blackburn H, Puchner TC, Eisenberg P, Ribeiro F,
Meja M. Sex differences in the electrocardiogram.
Circulation. 1960;22:598-601.
5. Nemati M, Doyle JT, McCaughan D, Dunn R, Pipberger HV. The orthogonal electrocardiogram in normal women: implications of sex differences in electrocardiography. Am Heart J. 1978;95:12-21. [Medline] [Order article via Infotrieve]
6. Macfarlane PW, Coleman EN, Pomphrey EO, McLaughlin S, Houston A, Aitchison T. Normal limits of the high-fidelity pediatric ECG. J Electrocardiol. 1989;22(suppl):162-168.
7.
Ostrander LD, Brandt RL, Kjelsberg MO, Epstein FH.
Electrocardiographic findings among the adult population of a total
natural community, Tecumseh, Michigan.
Circulation. 1965;31:888-898.
8.
Sotobata I, Richman H, Simonson E. Sex differences in the
vectorcardiogram. Circulation. 1968;37:438-448.
9. Siegel RJ, Roberts WC. Electrocardiographic observations in severe aortic valve stenosis: correlative necropsy study to clinical, hemodynamic, and ECG variables demonstrating relation of 12-lead QRS amplitude to peak systolic transaortic pressure gradient. Am Heart J. 1982;103:210-221. [Medline] [Order article via Infotrieve]
10. Casale PN, Devereux RB, Kligfield P, Eisenberg RR, Miller DH, Chaudhary BS, Phillips MC. Electrocardiographic detection of left ventricular hypertrophy: development and prospective validation of improved criteria. J Am Coll Cardiol. 1985;6:572-580. [Abstract]
11.
Casale PN, Devereux RB, Alonso DR, Campo E, Kligfield P.
Improved sex-specific criteria of left ventricular hypertrophy for
clinical and computer interpretation of electrocardiograms: validation
with autopsy findings. Circulation. 1987;75:565-572.
12. Rautaharju PM, La Croix AZ, Savage DD, Haynes SG, Madans JH, Wolf HK, Hadden W, Keller J, Cornoni-Huntley J. Electrocardiographic estimate of left ventricular mass versus radiographic cardiac size and the risk of cardiovascular disease mortality in the epidemiologic follow-up of the first National Health and Nutrition Examination Survey. Am J Cardiol. 1988;62:59-66. [Medline] [Order article via Infotrieve]
13. Kornreich F, Montague TJ, van Herpen G, Rautaharju PM, Smets P, Dramaix M. Improved prediction of left ventricular mass by regression analysis of body surface potential maps. Am J Cardiol. 1990;66:485-492. [Medline] [Order article via Infotrieve]
14. Norman JE, Levy D, Campbell G, Bailey JJ. Improved detection of echocardiographic left ventricular hypertrophy using a new electrocardiographic algorithm. J Am Coll Cardiol. 1993;21:1680-1686. [Abstract]
15.
Romhilt DW, Bove KE, Norris RJ, Cayners E, Conradi S, Rowlands
DT, Scott RC. A critical appraisal of the electrocardiographic criteria
for the diagnosis of left ventricular hypertrophy.
Circulation. 1969;40:185-195.
16. Sokolow M, Lyon TP. The ventricular complex in left ventricular hypertrophy as obtained by unipolar precordial and limb leads. Am Heart J. 1949;37:161-186. [Medline] [Order article via Infotrieve]
17.
Levy D, Labib SB, Anderson KM, Christiansen JC, Kannel WB,
Castelli WP. Determinants of sensitivity and specificity of
electrocardiographic criteria for left ventricular hypertrophy.
Circulation. 1990;81:815-820.
18. Timmis GC, Bakalyar DM, Gordon S. Accuracy of computerized electrocardiographic identification of left ventricular hypertrophy as determined by echocardiographic measurements of left ventricular mass: evaluation of a widely used computer program. J Am Coll Cardiol. 1986;8:301-309. [Abstract]
19. Savage DD, Garrison RJ, Kannel WB, Levy D, Anderson SJ, Stokes J III, Feinleib M, Castelli WP. The spectrum of left ventricular hypertrophy in a general population sample: The Framingham Study. Circulation. 1987;75(suppl I):I-26-I-33.
20. Molloy TJ, Okin PM, Devereux RB, Kligfield P. Electrocardiographic detection of left ventricular hypertrophy by the simple QRS voltage-duration product. J Am Coll Cardiol. 1992;20:1180-1186. [Abstract]
21. Pipberger HV, Arzbaecher RC, Berson AS, Briller SA, Brody DA, Flowers NC, Geselowitz DB, Lepeschkin E, Oliver GC, Schmitt OH, et al. Recommendations for standardization of leads and specifications for instruments in electrocardiography and vectorcardiography: Report of the Committee on Electrocardiography, American Heart Association. Circulation. 1975;52(suppl I):I-1-I-31.
22. Sahn DJ, DeMaria A, Kisslo J, Weyman A. Recommendations regarding quantitation in M-mode echocardiography: results of a survey of echocardiographic measurements. Circulation. 1978; 58:1072-1083.
23. Schiller NB, Shah PM, Crawford M, DeMaria A, Devereux R, Feigenbaum H, Gutgesell H, Reichek N, Sahn D, Schnittger I, et al. Recommendations for quantitation of the left ventricle by two-dimensional echocardiography. J Am Soc Echocardiogr. 1989;2: 358-367.
24. Devereux RB, Alonso DR, Lutas EM, Gottlieb GJ, Campo E, Sachs I, Reichek N. Echocardiographic assessment of left ventricular hypertrophy: comparison to necropsy measurements. Am J Cardiol. 1986;57:450-458. [Medline] [Order article via Infotrieve]
25. Hammond IW, Devereux RB, Alderman MH, Lutas EM, Spitzer MC, Crowley JS, Laragh JH. The prevalence and correlates of echocardiographic left ventricular hypertrophy among employed patients with uncomplicated hypertension. J Am Coll Cardiol. 1986;7:639-650. [Abstract]
26. Casale PN, Devereux RB, Milner M, Zullo G, Harshfield GA, Pickering TG, Laragh JH. Value of echocardiographic measurement of left ventricular mass in predicting cardiovascular morbid events in hypertensive men. Ann Intern Med. 1986;105: 173-178.
27. Koren MJ, Devereux RB, Casale PN, Savage DD, Laragh JH. Relation of left ventricular mass and geometry to morbidity and mortality in men and women with uncomplicated essential hypertension. Ann Intern Med. 1991;114:345-352.
28. Metz CE, Wang P, Kronman HB. A new approach for testing the significance of differences between ROC curves measured from correlated data. In: Deconick F, ed. Information Processing in Medical Imaging. The Hague, Netherlands: Martinus Nijhoff. 1984:432-445.
29. deSimone G, Daniels SR, Devereux RB, Meyer RA, Roman MJ, DeDivitis O, Alderman MH. Left ventricular mass and body size in normotensive children and adults: assessment of allometric relations and impact of overweight. J Am Coll Cardiol. 1992; 20:1251-1260.
30. Devereux RB, Lutas EM, Casale PN, Kligfield P, Eisenberg RR, Hammond IW, Miller DH, Reis G, Alderman MH, Laragh JH. Standardization of M-mode echocardiographic left ventricular anatomic measurements. J Am Coll Cardiol. 1984;4:1222-1230. [Abstract]
31. Hashida E, Nishi T. Constitutional and echocardiographic variability of the normal electrocardiogram in children. J Electrocardiol. 1988;21:231-237. [Medline] [Order article via Infotrieve]
32.
Devereux RB, Phillips MC, Casale PN, Eisenberg RR, Kligfield
P. Geometric determinants of electrocardiographic left ventricular
hypertrophy. Circulation. 1983;67:907-911.
33.
LaMonte CS, Freiman AS. The electrocardiogram after
mastectomy. Circulation. 1965;32:746-754.
34. Schillaci G, Verdecchia P, Borgioni C, Ciucci A, Guerrieri M, Zampi I, Battistelli M, Bartoccini C, Porcellati C. Improved electrocardiographic diagnosis of left ventricular hypertrophy. Am J Cardiol. 1994;74:714-719. [Medline] [Order article via Infotrieve]
35. Mensah GA, Pappas TW, Koren MJ, Ulin RJ, Laragh JH, Devereux RB. Comparison of classification of the severity of hypertension by blood pressure level and by World Health Organization criteria in the prediction of concurrent cardiac abnormalities and subsequent complications in essential hypertension. J Hypertens. 1993;11:1429-1440. [Medline] [Order article via Infotrieve]
36. Roman MJ, Kligfield P, Devereux RB, Niles NW, Hochreiter C, Halle C, Sato N, Borer JS. Geometric and functional correlates of electrocardiographic repolarization and voltage in aortic regurgitation. J Am Coll Cardiol. 1987;9:500-508. [Abstract]
37. Levy D, Garrison RJ, Savage DD, Kannel WB, Castelli WP. Left ventricular mass and incidence of coronary heart disease in an elderly cohort. Ann Intern Med. 1989;110:101-107.
38. Levy D, Garrison RJ, Savage DD, Kannel WB, Castelli WP. Prognostic implications of echocardiographically determined left ventricular mass in the Framingham Heart Study. N Engl J Med. 1990;322:1561-1566. [Abstract]
39. Ghali JK, Liao Y, Simmons B, Castaner A, Cao G, Cooper RS. The prognostic role of left ventricular hypertrophy in patients with or without coronary artery disease. Ann Intern Med. 1992;117:831-836.
40. Devereux RB, Casale PN, Wallerson DC, Kligfield P, Hammond IW, Liebson PR, Campo E, Alonso DR, Laragh JH. Cost-effectiveness of echocardiography and electrocardiography for detection of left ventricular hypertrophy in patients with systemic hypertension. Hypertension. 1987;9(suppl II):II-69-II-76.
41. Okin PM, Roman MJ, Devereux RB, Borer JS, Kligfield P. Electrocardiographic diagnosis of left ventricular hypertrophy by the time-voltage integral of the QRS. J Am Coll Cardiol. 1994;23:133-140.[Abstract]
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