Variability and concordance of Cornell and Sokolow–Lyon electrocardiographic criteria in hypertensive patients

Figures & data

Table I. Sample characteristics (n =103).

Women	60±58.3
Age (years), mean ± SD	66.8±8.8
BMI, kg/m^2	29.9±4.8
SBP/DBP, mmHg	141.6±15.1/78.7±9.0
Heart rate (beats/min), mean ± SD^a	72.7±11.2
Waist circumference (cm), mean ± SD^a	101.9±10.5
Diabetes mellitus	24±23.3
Hypercholesterolemia	42±40.8
Smoking	15±14.6
Associated cardiovascular disease	11±10.7
Antihypertensive therapy	96±93.2

BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure. Figures are number (percentage) or mean±standard deviation, SD. ^aMissing data: Waist circumference 11 (10.7%); heart rate: 15 (14.6%).

Table II. Characteristics of electrocardiographic readings.

Number of readings				824
Time between both ECGs (days), mean ± SD ICC, Cornell criterion (within-rater)				5.58±3.92
First rater
Baseline ECG				0.96 (0.94–0.97)
Final ECG				0.98 (0.97–0.98)
Second rater
Baseline ECG				0.95 (0.93–0.97)
Final ECG				0.92 (0.89–0.95)
ICC, Sokolow–Lyon criteria (within-rater)
First rater
Baseline ECG				0.97 (0.96–0.98)
Final ECG				0.99 (0.98–0.99)
Second rater
Baseline ECG				0.96 (0.94–0.97)
Final ECG				0.98 (0.98–0.99)
ICC, Cornell criteria (between-rater^a)
Baseline ECG				0,97 (0.96–0.98)
Final ECG				0.97 (0.96–0.98)
ICC, Sokolow–Lyon criteria (between-rater^a)				0.98 (0.97–0.99)
Baseline ECG
Final ECG				0.99 (0.98–0.99)
	Baseline ECG, mean ± SD of the 4 readings, range	Final ECG, mean ± SD of the 4 readings, range	p-value^b	Mean ± SD of all readings, range
Cornell criteria (mm)	12.91 (4.81), (3–29)	13.16 (4.83), (1–25)	0.381	13.04 (4.89) (1–29)
Sokolow–Lyon criteria (mm)	19.07 (5.74), (8–39)	18.13 (5.75), (6–33)	0.005	18.60 (5.80) (6–39)

Abbreviations: SD: standard deviation; ICC: intraclass correlation coefficient; ECG: electrocardiogram. ^aDegree of agreement between the mean of readings for each rater.

^bp-value was calculated with paired t-test, comparing the first with the second ECG.

Figure 1. Bland–Altmann graphs. Difference between the means of the readings of the baseline electrocardiogram (ECG) and the final ECG with regard to the mean of all readings.

Table III. Fixed and random parameters from a cross-classified multilevel linear regression model on Cornell and Sokolow–Lyon criteria (824 electrocardiographic readings).

	Cornell			Sokolow–Lyon
	Adjusted β^a	(95% CI)	p-value	Adjusted β^a	(95% CI)	p-value
Fixed parameters
Age, 5 years	0.79	(0.49–1.28)	0.332	0.58	(0.32–1.04)	0.067
Gender (male vs female)	0.53	(− 1.24 to 2.30)	0.558	1.03	(− 1.01 to 3.07)	0.321
BMI	0.10	(− 0.08 to 0.28)	0.281	− 0.37	(− 0.58 to − 0.16)	0.001
Diabetes mellitus	− 1.33	(− 3.36 to 0.70)	0.200	− 1.27	(− 3.60 to 1.07)	0.287
SBP	0.07	(0.01 to 0.13)	0.016	0.07	(0.01 to 0.14)	0.035
DBP				− 0.04	(− 0.17 to 0.08)	0.473
	Variance (SE)	ICC (%)^c		Variance (SE)	ICC (%)^c
Random parameters^b
Patient-level	16.45 (2.63)	75.4		21.75 (3.47)	76.9
ECG-level	4.10 (0.61)	18.8		5.60 (0.81)	19.8
Rater-level	0.13 (0,06)	0.6		0.08 (0.04)	0.3
Residual	1.13 (0.07)	5.2		0.86 (0.05)	3.0

CI, confidence interval; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; SE, standard error; ICC, intraclass correlation coefficient. Final models were adjusted for relevant and significant variables. ^aAdjusted β, regression coefficient of the association between each variable in the model and Cornell or Sokolow–Lyon criteria, controlling for the other variables in the model. ^bRandom parameters are multilevel measures of criterion variation. ^cThe ICC estimates the proportion of total variance in the Cornell or Sokolow–Lyon criterion that is attributable at each level.

Table IV. Factors associated with poor concordance between baseline and final ECG for Cornell and Sokolow–Lyon criteria.

	Cornell Adjusted^a					Sokolow–Lyon Adjusted^a
Logistic regression model (n =103 patients)	OR	(95% CI)	p-value	OR	(95% CI)	p-value
Sokolow–Lyon baseline ECG	1.20	(1.09–1.32)	<0.001	1.10	(1.01–1.18)	0.020
Cornell baseline ECG	1.11	(1.00–1.24)	0.044
Age, 5 years	1.49	(1.09–2.05)	0.013	1.15	(0.90–4.47)	0.258
Gender (male vs female)	0.69	(0.26–1.85)	0.463	1.56	(0.66–3.66)	0.308
Diabetes mellitus	0.90	(0.28–2.90)	0.860	0.57	(0.21–1.58)	0.283
SBP	0.94	(0.90–0.98)	0.002
DBP	1.09	(1.02–1.17)	0.010

Final models were adjusted for relevant and significant variables. The value of each ECG was calculated based on the mean of all its readings. OR, odds ratio; CI, confidence interval; SBP, systolic blood pressure; DBP, diastolic blood pressure. ^aAdjusted OR represents the association between each variable in the model and Cornell or Sokolow–Lyon criteria, controlling for the other variables in the model. A value greater than 1 indicates positive association with poor concordance.