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Eur J Epidemiol DOI 10.1007/s10654-008-9234-6 CARDIOVASCULAR DISEASE Electrocardiographic criteria of left ventricular hypertrophy in general population Edoardo Casiglia Æ Laura Schiavon Æ Valérie Tikhonoff Æ Anna Bascelli Æ Bortolo Martini Æ Alberto Mazza Æ Sandro Caffi Æ Daniele D0 Este Æ Francesco Bagato Æ Monica Bolzon Æ Federica Guidotti Æ Hilda Haxhi Nasto Æ Mario Saugo Æ Francesco Guglielmi Æ Achille C. Pessina Received: 11 August 2006 / Accepted: 19 February 2008 Springer Science+Business Media B.V. 2008 Abstract The question on whether the electrocardiographic criteria are reliable for detection of left ventricular hypertrophy (LVH) and play a role in predicting outcome is open. Answer can only proceed from population-based studies over unselected people followed up for years. In this study, 1,699 subjects from general population underwent echocardiogram and standard electrocardiogram (ECG) codified for LVH with Minnesota code and with other five methods. Other items were also recorded and used as covariables. Left ventricular mass index (LVMI) was 127.6 ± 44.9 g m-2 in men and 120.8 ± 41.2 g m-2 in women, and correlated directly with age in both genders. Prevalence of echocardiographic LVH was 36.6% in men and 53.4% in women. LVMI correlated directly with the E. Casiglia (&) L. Schiavon V. Tikhonoff A. Bascelli F. Bagato M. Bolzon F. Guidotti H. H. Nasto A. C. Pessina Department of Clinical and Experimental Medicine, University of Padova, Via Giustiniani No. 2, 35128 Padova, Italy e-mail: [email protected] B. Martini Department of Cardiology, General Hospital of Schio, Schio, Italy A. Mazza Department of Internal Medicine, General Hospital of Rovigo, Rovigo, Italy S. Caffi M. Saugo Department of Cardiology, General Direction and Data Elaboration Centre, General Hospital of Thiene, Thiene, Italy D. D0 Este Department of Cardiology, Hospital of Mirano, Mirano, Italy F. Guglielmi Department of Cardiology, Hospital of Thiene, Thiene, Italy Sokolow–Lyon score in both genders at any age, with the Romhilt–Estes, Cornell and RaVL scores in all subjects but elderly men, and with the Lewis score in men and women aged B69 years. Sensitivity and the predictive value of electrocardiographic tests, as well as the prevalence of LVH diagnosed with electrocardiographic criteria, were always low. Specificity was high for all the tests, and in particular for the Cornell index. Only when diagnosed with echocardiogram or with the Sokolow–Lyon criterion, LVH was an independent predictor of mortality. We conclude that electrocardiographic tests cannot be used as a surrogate of echocardiogram in detecting LVH in the general population because their positive predictive value (PPV) is unacceptably low. On the contrary, they could replace echocardiography in the follow up and for prediction of outcome, when LVH has previously been correctly diagnosed with other methods. Keywords Mortality Population Epidemiology Electrocardiogram Echocardiogram Abbreviations CASTEL CArdiovascular STudy in the ELderly CI Confidence interval ECG Electrocardiogram EDIVS End-diastolic inter-ventricular septum FN False negative FP False positive LEOGRA Last Evidences of Genetic risk factors in the Aged LVEDD Left ventricular end-diastolic diameter LVEDPWT Left ventricular posterior wall thickness LVH Left ventricular hypertrophy LVM Left ventricular mass LVMI Left ventricular mass index 123 E. Casiglia et al. NPV PPV RR VN VP Negative predictive value Positive predictive value Relative risk Very negative Very positive Introduction Although newer diagnostic tools are available, the electrocardiogram (ECG) remains the most common mean for evaluating cardiac disease. In particular, several ECG criteria have been proposed for the detection of left ventricular hypertrophy (LVH) both in clinical practice and in epidemiological studies. Nevertheless, doubts have been raised about their predictive value, particularly in the elderly, where cardiac fibrosis is highly represented [1, 2]. Left ventricular mass (LVM) tends to increase with age, mainly due to increase in electrically-inactive fibrous tissue [3–5]. Furthermore, in the elderly the ECG abnormalities that are commonly attributed to LVH often depend on conduction defects rather than on increase of muscular tissue [6], making the ECG diagnosis of LVH less precise. ECG tests of LVH have particularly been accused of having low sensitivity, leading particularly in the elderly to underestimation of LVH, to errors in detecting LVH regression in clinical trials, and to inclusion of a great number of subjects in erroneous percentiles in epidemiological studies [7]. This problem is still open. In fact, the only way to clarify whether or not ECG criteria are reliable in diagnosing LVH in the elderly is to test them against a echocardiography in a population-based frame, but only a very limited number of epidemiological studies were specifically dedicated to this question in the elderly. The present analysis is aimed at evaluating (1) the prevalence of LVH diagnosed with echocardiography and with different ECG criteria in elderly versus younger subjects from the general population, (2) the reliability of the ECG criteria in epidemiological and clinical settings, and (3) their role, if any, in predicting outcome. For these purposes, a large general population was employed [8–14]. Methods General protocol of the study The here described analysis was performed in the frame of the CArdiovascular STudy in the Elderly (CASTEL) and of the Last Evidences Of Genetic Risk factors in the Aged (LEOGRA) [8–14] studies. The aim of these studies was to evaluate the prevalence of hypertension, the cardiovascular 123 risk pattern and the feasibility of a program for hypertension control in general population. The CASTEL included 3,282 subjects and the LEOGRA 1,457 subjects aged 65–95 years from the northern Italian towns of Castelfranco Veneto, Chioggia, Torrebelvicino and Valli del Pasubio, all at few kilometers from each other. For the aims of the present analysis the subjects were cumulated together, being the two studies identical in protocol and procedures. The response rate was 73%. The characteristics of the subjects who gave informed consent and were enrolled did not differ significantly from those of subjects who did not participate. When subjects had more than one ECG, only the best-quality one was considered. Subjects with artificially paced rhythms and pre-excitation syndrome were excluded; 1,298 subjects had good-quality ECG recording and echocardiogram, gave informed consent and entered the here described analysis. The general characteristics of subjects included in the analysis did not differ significantly from those of subjects who were not included. As control cohort, 200 men and 201 women aged 18– 64 years representative subjects representative of the younger population of the same geographical area, identified from the register’s office files, were studied with the same procedures used for elderly subjects. The analysis was therefore performed on a total of 1,699 subjects, whose general characteristics are shown in Table 1. Clinical and instrumental measurements Anthropometrics Body weight (in kg) was measured while fasting with a mechanical device with the subjects wearing underwear, body height (in m) was measured without shoes. Body mass index was calculated (in kg m-2) as weight/squared height ratio. Blood pressure Lying arterial blood pressure was measured by trained doctors with a mercury manometer. Eight measurements were taken: 3 at 15-min intervals at baseline, 3 at 15-min interval a month later, and 2 at 15-min interval after another month. To minimize the alert reaction and white coat effects, if any, the average of the last two measurements was taken into account for the analysis of data. Any terminal digit preference was also avoided. Electrocardiogram Standard 12-lead ECG was codified with Minnesota code [15] and with other five methods (the Sokolow and Lyon criterion [16], the Romhilt and Estes point score system Electrocardiographic criteria of LVH Table 1 General characteristics of the study population Whole population (n = 1,699) Men (n = 707) Age (years) 65.8 ± 14.3 (65.1–66.5) 64.1 ± 14.5 (63.1–65,2) 66.9 ± 14.0 (66.1–67.8)* Body mass index (kg m-2) 26.6 ± .4.3 (26.4–26.8) 26.7 ± 3.7 (26.4–27.0) 26.6 ± 4.6 (26.3–26.9) Total cholesterol (mg dl-1) 222.6 ± 44.3 (220.5–224.7) 215.5 ± 41.6 (212.4–218.6) 227.7 ± 45.5 (224.8–230.5)* -1 Women (n = 992) Triglycerides (mg dl ) 123.3 ± 79.3 (119.5–127.1) 130.4 ± 92.1 (123.6–137.3) 118.3 ± 68.3 (114.0–122.5)* HDL-C (mg dl-1) 49.8 ± 15.2 (49.0–50.5) 46.2 ± 14.4 (45.1–47.2) 52.3 ± 15.2 (51.4–53.3)* Glycemia (mg dl-1) 105.7 ± 24.7 (104.5–106.9) 107.4 ± 24.6 (105.6–109.3) 104.5 ± 24.7 (102.9–106.0)* Creatininemia (mg dl-1) 0.91 ± 0.22 (0.90–0.92) 0.99 ± 0.21 (0.97–1.00) 0.85 ± 0.21 (0.84–0.86)* Uric acid (mg dl-1) 5.17 ± 1.41 (5.11–5.24) 5.68 ± 1.34 (5.58–5.78) 4.82 ± 1.36 (4.73–4.90)* Cigarettes (die-1) 1.39 ± 4.20 (1.19–1.59) 2.24 ± 5.53 (1.83–2.65) 0.79 ± 2.77 (0.62–0.96)* VC (% theoretical) 80.6 ± 19.8 (79.6–81.5) 79.6 ± 19.6 (78.1–81.0) 81.3 ± 20.0 (80.1–82.6)* FEV1 (% theoretical) Na (mEq l-1) 81.2 ± 21.6 (80.2–82.2) 141.5 ± 2.5 (141.4–141.7) 82.0 ± 21.1 (80.4–83.6) 141.2 ± 2.5 (141.0–141.4) 80.6 ± 22.0 (79.2–82.0) 141.8 ± 2.4 (141.6–141.9)* K (mEq l-1) 4.22 ± 0.44 (4.20–4.24) 4.25 ± 0.44 (4.22–4.29) 4.19 ± 0.44 (4.17–4.22)* Hematocrit (%) 41.9 ± 3.4 (41.7–42.0) 43.7 ± 2.0 (43.4–43.9) 30.6 ± 3.1 (40.4–40.8)* Systolic blood pressure (mmHg) 160.5 ± 25.6 (159.2–161.7) 158.7 ± 23.8 (156.9–160.4) 161.7 ± 26.7 (160.1–163.4)* Diastolic blood pressure (mmHg) 89.9 ± 10.8 (89.3–90.4) 90.4 ± 10.4 (89.6–91.2) 89.5 ± 11.1 (88.8–90.2)* Heart rate (bpm) 71.2 ± 10.1 (70.7–71.7) 69.2 ± 10.2 (68.5–70.0) 72.6 ± 9.7 (72.0–73.2)* Alcohol (ml 9 die-1) 36.5 ± 34.4 (34.8–38.1) 54.1 ± 43.4 (50.9–57.4) 23.9 ± 17.3 (22.8–24.9)* Diabetes (%) 237/1699 (13.9) 102/707 (14.4) 135/992 (13.6) Respiratory insufficiency (%) 847/1699 (49.8) 391/707 (66.3) 456/992 (46.0)* Mean ± standard deviation (95% CIs) are shown * p \ 0.001 men versus women HDL-C, high-density-lipoprotein serum cholesterol; VC, vital capacity; FEV1, forced expiratory volume in 1 s; Na and K, serum sodium and potassium [17], the Lewis index [18], the R in aVL (RaVL) voltage criterion [19, 20] and the Cornell score [21, 22]) by an expert who did not know the aim and design of the study. The cut-off values are summarized in Table 2. According to Casale [21, 22], the Cornell cut-off was different in men and women. More than 30 ECG criteria of LVH have been proposed, but those mentioned above are the most commonly used in clinical practice and epidemiology. Echocardiogram Although magnetic resonance imaging has been suggested to be the best way to check for LVH in limited numbers of patients and volunteers [23], practical and economical considerations make obviously impossible the use of this technique in large-scale population-based studies including a great number of subjects. Echocardiographic diagnosis of LVH has notoriously good sensitivity and specificity when compared to post-mortem weighing of heart [24–27], represents the method of choice for the evaluation of LVH in vivo [28] and has been approved [28] for validation of ECG criteria. M-mode 2D-guided echocardiogram (Megas device, Esaote, Firenze, Italia) was therefore chosen as a gold standard. For the purpose of the present study, left ventricular end-diastolic diameter (LVEDD), end-diastolic inter-ventricular septum (EDIVS) and left ventricular posterior wall thickness (LVEDPWT) were measured according to the American Society of Echocardiography and Penn convention [29]. Recordings were analyzed automatically during the exam using the inner software, and simultaneously printed and then analyzed separately by an independent operator who did not know the aim and design of the study. Average of the two measurements was used for analysis of data. LVM was calculated from [29]: LVM ðgÞ ¼ 0:832 ½ðEDIVS þ LVEDD þ LVEDPWTÞ3 ðLVIDÞ3 þ 0:6 and indexed [Left ventricular mass index (LVMI), g m-2] for body surface area (m2) calculated from [30] 71.84 9 weight0.425 9 heigth0.725. As suggested by Hamkg mond et al. [31], echocardiographic diagnosis of LVH was based on LVMI [134 g m-2 in men or [110 g m-2 in women. Other methods of diagnosis and cut-off values 123 E. Casiglia et al. Table 2 Electrocardiographic criteria of left ventricular hypertrophy Method of detection Criteria Cut-off values for LVH Sokolow and Lyon score system S amplitude in V1 + R amplitude in V5 or V6 C35 mm Romhilt and Estes points system Amplitude criteria (highest R or lowest S in limb leads C20 mm, or S in V1 or V2 C30 mm, or R in V5 or V6 C30 mm): 3 points; typical ST-T: 3 points; left atrial enlargement (P wave C40 ms and terminal negativity C1 mm in V1): 3 points; left axis deviation: 2 points; QRS C90 ms: 1 point; intrinsecoid deflection C50 ms in V5 or V6: 1 point. The score must be reduced by 1 point in the presence of digitalic treatment C 4 points Lewis score system Net positivity in I + net negativity in III C17 mm Cornell index S amplitude in V1 + R amplitude in aVL [25 mm in men or [22 mm in women Minnesota code Code 3.1: R amplitude [26 mm in V5 or V6; or [20 mm in any I, II, II or aVF; or [12 mm in aVL. Code 3.3: R amplitude 15 B 20 mm in I, or R amplitude in V5 or V6 + S amplitude in V1 [35 mm code 3.1 or 3.3 R in aVL system R amplitude in aVL C11 mm were proposed [28, 32], but those just mentioned have been preferred because largely adopted and validated. considering as prevalence in each age and sex group that given by: Reliability of ECG tests prevalence ¼ ðtrue positives þ false negativesÞ=numerosity. To test reliability of ECG criteria of LVH, sensitivity, specificity, and the predictive value of positive and negative results, were employed. Sensitivity [33] was calculated from two-way tables in relation to the gold standard from the algorithm: sensitivity ð%Þ ¼ ½true positives=ðtrue positives þ false negativesÞ 100 and specificity [32] from the algorithm: specificity ð%Þ ¼ ½true negatives=ðtrue negatives þ false positivesÞ 100: According to Bayes’s approach [33, 34], the predictive values of a positive (PPV) or negative (NPV) ECG test was defined as: PPVð%Þ ¼½ðprevalence sensitivityÞ= fðprevalence sensitivityÞ þ ½ð1 prevalenceÞ ð1 specificityÞg 100 NPVð%Þ ¼½ð1 prevalenceÞ specificity= f½ð1 prevalenceÞ specificity þ ½prevalence ð1 sensitivity)]g 100 123 Mortality was drawn from the National Institute of Statistics forms and double-checked through the analysis of medical files and asking the general practitioners. Statistics Comparison between means was made with analysis of variance and the Tukey’s post-hoc test, that of frequencies with the v2 test. Linear correlations were evaluated with the Pearson coefficient and the Bonferroni’s conservative correction. Adjustment for confounders such as age, gender and body mass index were made when necessary in multiple regressions. Logistic regression was used to evaluate the relative weight of covariables on the dichotomic dependent variable LVH. Analysis of mortality was performed by the Mantel–Haenszel procedure after generating Kaplan–Meier survival curves. Relative risk (RR) of LVH as diagnosed with the different criteria was calculated, together with 95% confidence intervals (CI), from Cox multivariate analysis including as covariables body mass index, smoking, alcohol, serum lipids, diabetes and—when proper-age and gender. Statistical analysis was performed first on the entire population and then repeated after stratification for age and gender; for age stratification the value of median (69 years inclusive) was chosen as cut off. Electrocardiographic criteria of LVH Results General characteristics of the population Women were older than men and had higher values of serum total and HDL cholesterol, sodium, systolic blood pressure and heart rate; men had higher values of diastolic blood pressure, serum triglycerides, glucose, uric acid and potassium, higher hematocrit, and higher prevalence of smoking, drinking, diabetes and respiratory disease (Table 1). Echocardiographic LVH In the whole population, LVMI was 123.6 ± 42.9 g m-2, i.e. 127.6 ± 44.9 (CI 124.2–130.9) g m-2 in men and 120.8 ± 41.2 (CI 118.2–123.5) g m-2 in women (p = 0.002), and correlated directly with age both in men (r = 0.45, p = 0.0001) and women (r = 0.38, p = 0.0001). After stratification, LVMI was 110.6 ± 38.1 (CI 108.0– 113.2) g m-2 until 69 years and 137.4 ± 43.4 (CI 134.4– 140.4) g m-2 after this age (p \ 0.0001), with lower values in women (B69 years: 105.4 ± 35.3, CI 102.1–108.6 vs. g m-2; [69 years: 134.6 ± 41.2, CI 131.0–138.2 g m-2, p \ 0.0001) than in men (B69 years: 116.6 ± 40.2, CI 112.6–120.6 g m-2; p \ 0.0001 vs. women having the same age; [69 years: 142.1 ± 46.6, CI 136.7–147.5 g m-2, p = 0.02 vs. women having the same age). Up to 69 years of age, LVMI directly correlated with systolic blood pressure both in men (r = 0.41, p \ 0.001) and women (r = 0.52, p \ 0.005) even after correction for age and body mass index, while no correlation was present after 69 years of age, when LVMI was only predicted by body mass index (Fig. 1). Fig. 1 Correlation adjusted for body mass index of systolic blood pressure with echocardiographic left ventricular mass index (LVMI) and with the values of the electrocardiographic tests for LVH based on numeric scores. RaVL is the amplitude of the R wave in aVL lead. See Table 2 for score definition 123 E. Casiglia et al. Prevalence of echocardiographic LVH was 44.4% in the whole population, i.e. 36.6% in men (25.8% in those B69 years and 50.4% in those [69 years, p \ 0.0001) and 53.4% in women (38% in those B69 years, and 66.9% in those [69 years, p \ 0.0001) (p \ 0.0001 men vs. women for any age class). In multivariate logistic regression analysis adjusted for confounders, echocardiographic LVH was predicted by hypertension (RR 3.80, CI 2.70–5.34), also including as covariables age[69 years (RR 2.27, CI 1.83–2.82), female gender (RR 2.07, CI 1.67–2.55) and body mass index C25 kg m-2 (RR 1.25, CI 1.00–1.56). After stratification, hypertension predicted echocardiographic LVH both in men (RR 3.06, CI 1.56–5.98) and women (RR 6.90, CI 3.98–11.90) until 69 years, but not after this age. Electrocardiographic LVH The Sokolow–Lyon score correlated with systolic blood pressure in both genders at any age; the other scores are summarized in Fig. 1. LVMI correlated directly with the Sokolow–Lyon score in both genders at any age, with the Romhilt–Estes, Cornell and RaVL scores in all subjects but elderly men, and with the Lewis score in men and women aged B69 years. Sensitivity of the ECG tests of LVH is summarized in Table 3. The predictive value of a positive ECG test was always low (from 5.9% to 25.8%), and the prevalence of LVH diagnosed with the different ECG tests was always falsely low when compared to the gold standard (Fig. 2). In Table 3, the PPV and NPV of ECG tests are summarized. Before the age of 69 years, arterial hypertension predicted LVH diagnosed with the Sokolow–Lyon criterion in women (RR 4.10, CI 1.20–14.0), with the Romhilt–Estes score both in men (RR 2.82, CI 1.34-5-96) and women (RR 10.30, CI 2.97–35.40), with the Lewis criterion both in men (RR 16.4, CI 2.20–12.2) and women (RR 7.56, CI 2.29– 25.0), with Minnesota code both in men (RR 4.53, CI 1.74– 11.80) and women (RR 3.23, CI 1.09–9.53), and with the RaVL criterion both in men (RR 9.67, CI 1.28–73.1) and women (RR 13.8, CI 1.84–104.00). No prediction was possible after the age of 69 years. Only the Cornell criterion was able to put in evidence the higher prevalence of LVH in women (6.6%) than in men (2.8%, p \ 0.001 vs. women), a difference that was shown by the gold-standard. Nevertheless, due to low Table 3 Sensitivity, specificity, positive and NPVs of the five electrocardiographic tests of left ventricular hypertrophy Gender Age Men (n = 707) B69 (n = 396) [69 (n = 311) Women (n = 992) B69 (n = 461) [69 (n = 531) Sokolow– Lyon score Romhilt– Estes score Sensitivity (%) 17.0 22.5 Specificity (%) 90.8 86.1 PPV (%) 16.5 NPV (%) 84.5 Sensitivity (%) Specificity (%) PPV (%) NPV (%) Cornell index Lewis index Minnesota code R in aVL 5.9 16.0 23.5 8.0 99.3 92.1 90.1 94.2 21.6 5.9 15.4 21.5 8.2 79.3 95.1 85.5 79.4 92.8 16.7 25.5 3.8 10.9 17.2 7.1 82.5 77.3 96.1 86.4 92.9 92.2 17.5 25.8 4.0 11.7 16.3 7.4 83.5 75.2 97.0 89.3 84.6 93.6 Sensitivity (%) 10.3 15.4 10.3 13.1 9.1 5.2 Specificity (%) 97.6 96.2 97.6 93.7 96.2 63.4 PPV (%) 10.0 14.4 10.0 12.9 9.1 7.9 NPV (%) 90.9 86.5 91.0 88.1 91.9 93.6 Sensitivity (%) 12.7 14.6 10.1 16.7 12.7 7.9 Specificity (%) 93.7 86.9 97.2 89.7 92.6 93.1 PPV (%) 12.5 15.1 9.9 16.3 12.6 8.2 NPV (%) 88.5 86.0 91.1 84.6 88.4 92.8 TP, true positives; TN, true negatives; FP, false positives; FN, false negatives; PPV, positive predictive value; NPV, negative predictive value 123 Electrocardiographic criteria of LVH Fig. 2 Prevalence (black bars) of LVH as detected with the Sokolow and Lyon score system, the Romhilt and Estes point system, the Lewis score, the Cornell method and the Minnesota code as compared with echocardiographic LVH. See Table 2 for score definitions. Prevalence of echocardiographic LVH (open bars) is also shown for comparison sensitivity, this criterion was able to detect only a very limited fraction of LVH in both genders. Prognostic role of LVH Only the LVH diagnosed with echocardiogram and that diagnosed with the Sokolow–Lyon criterion were independent predictors of overall mortality (Fig. 4), with a RR of 1.36 (CI 1.01–1.83) for the former and 1.69 (CI 1.17– 2.43) for the latter. Age [69 years, diabetes and female gender acted in both cases as predictive covariables. When the two above mentioned criteria (echocardiography and Sokolow–Lyon) were both present (what happened in 6.2% of population), RR was 2.10 (CI 1.23–3.56). On the other hand, the presence of the echocardiographic criterion alone, being negative the Sokolow–Lyon, increased the risk insignificantly. Discussion Are ECG tests suitable for screening of LVH in the adult population? The answer to this question is clearly negative. As shown in Fig. 3, prevalence of LVH as detected with ECG criteria was always lower than that detected with the echocardiographic gold standard in both genders and in both age classes below or above 69 years. When detected with echocardiogram, prevalence of LVH was very high; when detected with ECG, it was low. This is not surprising, as echocardiogram detects the whole LVM (myocytes + fibrous matrix) while ECG indirectly extrapolates from electric vectors only the electrically-active mass represented by left ventricular vital myocytes [6]. Echocardiogram and ECG therefore give information about different aspects of cardiac anatomy. In this context, it is interesting to observe that echocardiographic LVMI was strictly age-dependent and did not correlate with systolic blood pressure in older subjects, where the fibrous component is particularly relevant. On the contrary, the Sokolow–Lyon score correlated with systolic blood pressure in both genders at any age, and the other numeric ECG scores correlated with systolic blood pressure in all subjects but elderly men (Fig. 1), thus demonstrating the more direct link of ECG scores with systolic work. The correlation between ECG indices and LVMI was practically limited to subjects B69 years; after this age, a correlation was only detectable in women for the Sokolow and Lyon, the Lewis and the Cornell scores (Fig. 1). It must be underlined that the high prevalence of LVH in the population (perfectly in line with the 28–71% found in 123 E. Casiglia et al. Fig. 3 Values of the electrocardiographic tests for LVH based on numeric scores, plotted against echocardiographic LVMI. Horizontal lines represent the cut-off values for echocardiographic LVH, vertical lines the cut-off values of electrocardiographic LVH with the different criteria. TP are the true positives, FP the false positives, TN the true negatives and FN the false negative versus the echocardiographic gold standard; s indicates subjects aged B69 years, • those aged [69 years 123 Electrocardiographic criteria of LVH Fig. 4 Cumulative survival during the 5 years of follow-up. Echo: echocardiographic LVH, SL: Sokolow–Lyon criterion many other large-scale studies) [35–38] could have contributed to keep low the sensitivity of the ECG criteria. A first conclusion of this population-based study is that the ECG tests cannot be used as a surrogate of echocardiogram in detecting LVH in a population, in a sample of persons and even in clinical practice, because they give information that are different from those given by echocardiogram and above all because PPV is unacceptably low (never over 27%). Diagnosing LVH with ECG therefore means mistaking by defect in a lot of cases. This limitation, due to high frequency of false negatives (FNs), is particularly evident for the Cornell criterion (that in our experience detected less than 6% of true hypertrophy among men) and for the RaVL criterion (that in both gender did not reach 8%). These two criteria can therefore lead to disownment of [90% of cases of LVH, erroneously labelleing them as normotrophic despite a LVMI over the recommended limits. Also with the other ECG criteria, the ability of detecting LVH was always inadequate, largely under the canonical 50% representing the PPV of the launch of a coin. The attitude of any tests to screen subjects with a trait is low when the trait prevalence is also low [34, 39]. This is also why in our experience the PPV of some ECG tests was greater in the cohort having higher prevalence of LVH (that of elderly women), however remaining, largely under a reasonable limit for epidemiological or clinical use. The reason why so many FNs are found with ECG probably depends on the fibrous tissue accompanying left ventricular myocytes that reduces surface potentials, particularly in limb leads and especially in the elderly. Coexistent myocardial ischemia (more frequent in old age, when ECG test of LVH are just less sensitive) may also interfere with ventricular conduction, further reducing surface potentials. These results are in agreement with those of other Authors. In the experience of Weber [40], like in our survey, ECG criteria were positive in \20% of subjects with LVMI [200 g m-2, and in that of Dollar and Roberts [41] only in 40% of subjects whose hearts weighted [500 g. They are, on the contrary, in disagreement with those of other Authors who occasionally found a surprisingly high sensitivity of voltage criteria [16–22, 24, 42, 43]. These discrepancies are most likely attributable to the choice of different gold standards, such as post-mortem examination or chest X-ray, as well as ti lack of utilization of samples representative of general population. When used in population screening or in the clinical milieu, all the ECG tests therefore appear to be inadequate; worse, they may furnish erroneous information leading in the first case to underevaluating the real prevalence of LVH in the population, in the second case to labelling subjects with LVH as normotrophic, and in both cases to including subjects in wrong categories. It would therefore be wrong to leave out of consideration echocardiography in population screening or for detecting hypertrophic subjects in clinical practice [44]. On the contrary, all the ECG tests used in the present study had high specificity. The Cornell was the criterion with the highest specificity (never under 96%) and highest negative predictive value (NPV; never under 91%), and also the only one able to detect the higher prevalence of LVH in women put in evidence by the gold standard. At variance, the Lewis and the RaVL criteria did not recognize any difference between genders, and the Sokolow–Lyon criterion, the Romhilt–Estes score and the Minnesota code even detected higher prevalence in men than in women. Practically all the subjects labelled as hypertrophic by the Cornell criterion were really hypertrophic at the gold standard, an agreement that was higher in men aged B69% 123 E. Casiglia et al. and lower—but anyhow very high—in those who were [69 years old. Diagnosing LVH through the Cornell criterion implied a risk of including less than 9% of normotrophics, an error that came down to 3% in elderly men. Having high specificity and high NPV, and correlating well with LVMI, the ECG tests (particularly the Sokolow– Lyon, the Romhilt–Estes and the Lewis) could legitimately replace echocardiography provided that LVH has previously been correctly diagnosed with other methods (for instance in regression trials) [45–47]. Apart from echocardiography, only the Sokolow–Lyon method—despite its low sensitivity—was able to predict mortality (Fig. 4). This finding is in agreement with the results obtained in patients by Richardson et al. [48] and in general population by Sundström et al. [49]. Not only this, but also in our survey the excess mortality observed in subjects with echocardiographic LVH was limited to those who also had positive Sokolow–Lyon criterion; in these subjects, the risk of dying within 4 years was double than in normotrophic, while in those having nothing more than a positive echocardiogram the risk was only insignificantly increased. 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