Electrocardiographic changes in workers occupationally exposed to lead.
BACKGROUND
The significance of heavy metals in pathogenesis of the circulatory system diseases remains unresolved. The aim of the study was to evaluate electrocardiographic changes in workers occupationally exposed to lead without clinical presentation of cardiac involvement.


METHODS
A group of 60 smelters and refiners and 45 healthy men, as a control group, were enrolled. Twelve-lead electrocardiogram (ECG) and 24-hour Holter monitoring were performed. Further analysis included heart rate variability (HRV) in time and frequency domains and heart rate turbulence (HRT).


RESULTS
Analysis of 12-lead ECG recordings revealed various pathologies in 27 out of 60 men occupationally exposed to lead. Twenty-four-hour ECG Holter monitoring showed the higher mean heart rate in copper smelters than in healthy subjects (85.8 ± 14.1 bpm vs 72.6 ± 9.2 bpm; P < 0.05) and more premature supraventricular and ventricular contractions (298 ± 235 vs 27 ± 45; P < 0.05 and 152 ± 138 vs 18 ± 18; P < 0.05, respectively). The majority of time domain and frequency domain HRV parameters were significantly lower, and the LF:HF ratio was higher when compared with the control group. Turbulence onset was abnormal in six copper smelters and turbulence slope in five men exposed to lead.


CONCLUSIONS
Electrocardiographic evaluation showed that various heart rhythm disorders were more frequent in metallurgists, as compared to the control group, and the decreased HRV and abnormal parameters of HRT were observed. Noninvasive electrocardiographic evaluation could be a valuable method of the early prediction of cardiovascular disorders in men occupationally exposed to lead.
Department of Internal Medicine, Occupational Diseases and Hypertension, Wroclaw Medical University, 4 Pasteur Street, Wroclaw, Poland. sogood@poczta.onet.pl
Rafał
R
Poręba
Małgorzata
M
Poręba
Paweł
P
Gać
Aleksandra
A
Steinmetz-Beck
Bogusław
B
Beck
Witold
W
Pilecki
Ryszard
R
Andrzejak
Małgorzata
M
Sobieszczańska
D001145:Arrhythmias, Cardiac / Q000453:epidemiology* / Q000503:physiopathology; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D006339:Heart Rate; D006801:Humans; D007854:Lead; D008297:Male; D008669:Metallurgy; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology* / Q000503:physiopathology; D016273:Occupational Exposure / Q000009:adverse effects*
D007854:Lead
Circulation. 1996 Dec 1;94(11):2850-5
8941112
Ann Neurol. 1985 Jul;18(1):1-13
3898997
Environ Health Perspect. 1988 Jun;78:91-9
3060356
Environ Res. 1993 May;61(2):323-36
8495674
Environ Toxicol Pharmacol. 2010 May;29(3):266-70
21787612
Ann Noninvasive Electrocardiol. 2009 Oct;14(4):327-32
19804508
Environ Health Perspect. 1988 Jun;78:101-6
3060351
Lancet. 1999 Apr 24;353(9162):1390-6
10227219
Clin Chim Acta. 1972 Mar;37:443-7
5022108
Vet Hum Toxicol. 1990 Apr;32(2):152-3
2327064
Med Pr. 1990;41(3):152-8
2233239
J Am Coll Cardiol. 1996 Aug;28(2):296-304
8800101
Am J Cardiol. 2004 Aug 15;94(4):465-9
15325930
Proc Natl Acad Sci U S A. 1981 Oct;78(10):6494-8
6947240
J Am Coll Cardiol. 2008 Oct 21;52(17):1353-65
18940523
Circulation. 1996 Mar 1;93(5):1043-65
8598068
Am J Ind Med. 1996 Aug;30(2):155-63
8844045
Med Pr. 2004;55(2):139-44
15524081
Hum Exp Toxicol. 1996 May;15(5):400-5
8735464
Stroke. 1999 Oct;30(10):2246-7
10512934
Circ Res. 1987 Sep;61(3):429-35
3621502
Am Heart J. 1993 Sep;126(3 Pt 2):761-4
8362750
Clin Chem. 1981 Feb;27(2):220-2
7460270
Am J Ind Med. 1995 Aug;28(2):233-44
8585520
Pol Tyg Lek. 1985 Feb 4;40(5):125-7
3983006
Eur Heart J. 1998 Nov;19(11):1593-5
9857905
Cardiovasc J Afr. 2009 Sep-Oct;20(5):278-83
19907799
J Mol Cell Cardiol. 1974 Jun;6(3):285-90
4601060
Am J Cardiol. 2003 Jun 15;91(12):1471-4, A8
12804738
Circulation. 2000 Mar 7;101(9):948-54
10704159
Circulation. 1999 Oct 12;100(15):e65-6
10517745
Cardiol J. 2009;16(6):553-9
19950092
Environ Health Perspect. 1988 Jun;78:85-9
3060355
Wei Sheng Yan Jiu. 1998 Jan;27(1):9-11
10682631
Am J Physiol. 1980 Jul;239(1):H22-30
7396014
Ann Noninvasive Electrocardiol. 2005 Jan;10(1):88-101
15649244
Med Tr Prom Ekol. 1994;(12):17-21
7719652
Toxicol Lett. 1985 Apr;25(1):25-32
2986320
Vet Hum Toxicol. 1993 Dec;35(6):501-3
8303816
Nihon Eiseigaku Zasshi. 1999 Oct;54(3):516-25
10555440
Arch Neurol. 1990 May;47(5):513-9
2185720