Sensitivity and Specificity of an Electrocardiogram to Detect Echocardiographic Left Ventricular Hypertrophy in a Sample of 326 Tanzanian Adults: Differences in Men and Women

Figures & data

Table 1 Demographic and Clinical Characteristics of the Study Population

Characteristics	Men n = 135	Women n = 191	p-value
Age (years)	49.8±14.7	49.3±13.4	0.723
Height (cm)	167±8	156±6	<0.001
Weight (kg)	71.8±15.0	69.5±14.7	0.169
Body Mass Index (kg/m^2)	25.8±4.7	28.4±5.5	<0.001
Body Surface Area (m^2)	1.80±0.19	1.69±0.18	<0.001
Waist circumference (cm)	91±13	95±13	0.011
Pulse rate (beats/min)	76±14	79±14	0.013
Systolic Blood Pressure (mmHg)	146±24	147±27	0.745
Diastolic Blood Pressure (mmHg)	88±15	90±16	0.331
Pulse pressure (mmHg)	57±17	56±17	0.695
Fasting Blood Glucose (mmol/l)	7.8±4.4	8.0±4.1	0.611
Total cholesterol (mmol/l)	4.8±1.1	5.6±1.5	<0.001
HDL-C (mmol/l)	1.1±0.3	1.2±0.3	0.002
LDL-C (mmol/l)	3.4±1.0	4.0±1.4	<0.001
Tryglycerides (mmol/l)	1.5±0.8	1.6±1.2	0.237
Serum Creatinine (μmol/l)	117±86	93±43	0.002
Groups, n (%)
Hypertensive	44 (32.6)	76 (39.8)	0.096
Diabetic	59 (43.7)	87 (45.5)
Normal	32 (23.7)	28 (14.7)

Note: Results are mean ±SD unless stated otherwise.

Abbreviations: HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol.

Table 2 Mean Values for Electrocardiographic and Echocardiographic Findings in Men and Women

Findings	Men n = 135	Women n = 191	p-value
Electrocardiographic
S-amplitude in lead V1 (mm)	9.7±4.9	10.4±4.8	0.213
S-amplitude in lead V3 (mm)	14.3±8.1	11.9±6.8	0.003
R-amplitude in lead aVL (mm)	6.0±4.4	5.9±3.5	0.944
R-amplitude in lead V5 (mm)	21.0±8.4	14.8±6.0	<0.001
R-amplitude in lead V6 (mm)	18.0±7.6	14.3±5.8	<0.001
QRS duration (ms)	88±14	83±12	<0.001
Sum of SV1 + RV5 (mm)	30.7±10.9	25.2±8.8	<0.001
Sum of SV1 + RV6 (mm)	27.7±10.5	24.7±8.9	0.006
Cornell sum (mm)	20±9	18±8	0.012
Cornell product (mm × ms)	1824±1056	2139±775	<0.001
Echocardiographic
LV end diastolic diameter (cm)	4.6±0.6	4.4±0.6	<0.001
Intraventricular Septum in diastole (cm)	1.16±0.28	1.11±0.30	0.116
LV posterior wall in diastole (cm)	0.97±0.21	0.92±0.24	0.060
Relative wall thickness	0.43±0.12	0.43±0.14	0.781
LV Mass (g)	180.7±72.0	152.6±59.6	<0.001
LV Mass Index (g/m^2)	100.2±38.2	90.7±35.4	0.022

Abbreviation: LV, left ventricular.

Table 3 Clinical and Echocardiographic Correlation Coefficients (r) for Sokolow-Lyon and Cornell-Product Indices in Men and Women

Characteristics	Sokolow-Lyon (mm)		Cornell Product (mm × ms)
	Men	Women	Men	Women
Clinical	(r)	(r)	(r)	(r)
Age (years)	−0.222**	0.069^ns	0.113^ns	0.206**
Height (cm)	−0.227**	−0.209**	−0.050^ns	−0.272***
Weight (kg)	−0.231**	−0.198**	0.010^ns	−0.015^ns
Body Mass Index (kg/m^2)	−0.140^ns	−0.132^ns	0.053^ns	−0.118^ns
Waist circumference (cm)	−0.216*	−0.148*	0.064^ns	0.036^ns
Body Surface Area (m^2)	−0.256**	−0.223**	−0.010^ns	−0.175*
Systolic Blood Pressure (mmHg)	0.051^ns	0.324***	0.046^ns	0.397***
Diastolic Blood Pressure (mmHg)	0.103^ns	0.306***	0.077^ns	0.366***
Pulse pressure (mmHg)	−0.017^ns	0.226**	−0.002^ns	0.287***
Fasting Blood Sugar (mmol/l)	−0.012^ns	−0.197**	−0.134^ns	−0.079^ns
Total Cholesterol (mmol/l)	−0.172^ns	−0.068^ns	−0.171^ns	−0.012^ns
HDL-C (mmol/l)	−0.112^ns	0.079^ns	−0.156^ns	−0.140^ns
LDL-C (mmol/l)	−0.149^ns	−0.035^ns	−0.164^ns	0.018^ns
Triglycerides (mmol/l)	−0.068^ns	−0.085^ns	0.031^ns	0.029^ns
Serum Creatinine (μmol/l)	0.185*	0.241**	0.202*	0.195**
Echocardiographic
Intraventricular septum in diastole (cm)	−0.029^ns	0.193**	0.199*	0.304***
LV posterior wall in diastole (cm)	0.087^ns	0.256***	0.244**	0 294***
Relative wall thickness	−0.012^ns	0.145*	0.066^ns	0.140^ns
LV end diastolic diameter (cm)	0.179*	0.153*	0.247**	0 275***
LV mass (g)	0.136^ns	0.325***	0.351***	0.466***
LV mass index (g/m^2)	0.220**	0.400***	0.374***	0.534***

Abbreviations: HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; LV, left ventricular ^{*, **} and *** denotes significant levels at p < 0.05, < 0.01 and < 0.001, respectively. ns, not significant.

Figure 1 Prevalence of electro- and echo-cardiographic LVH in men and women.

Figure 2 Correlation between the S-L and C-P indices with echocardiographic LV mass index.

Table 4 Sensitivity and Specificity of the ECG in Detecting Echocardiographic LVH in Men and Women

ECG - Criteria	Men		Women
	Sensitivity	Specificity	Sensitivity	Specificity
Sokolow-Lyon	43.8% (14/32*100)	66.0% (68/103*100)	36.0% (18/50*100)	89% (126/141*100)
Confidence Interval	[26.8–62.1]	[55.9–74.9]	[23.3–50.9]	[82.8–93.7]
Cornell-Product	43.8% (14/32*100)	87.4% (90/103*100)	60.0% (30/50*100)	80.1% (113/141*100)
Confidence Interval	[26.8–62.1]	[79.0–92.8]	[45.2–73.3]	[72.4–86.2]
Both Criteria	28.1% (9/32*100)	95.1% (98/103*100)	28.0% (14/50*100)	95.0% (134/141*100)
Confidence Interval	[14.4–46.9]	[88.5–98.2]	[16.7–42.7]	[89.7–97.8]