Heart Asia. 2019 Jun 19;11(2):e011221. doi: 10.1136/heartasia-2019-011221. eCollection 2019.

Effects of heat stroke on surface ECG: a study on clinical outcomes.

Heart Asia

Amal Paul, Reginald Alex, John Roshan Jacob, Bijesh Yadav

PMID: 31297165 PMCID: PMC6590991 DOI: 10.1136/heartasia-2019-011221

Abstract

AIMS: Classic heat stroke is associated with high in-hospital mortality and morbidity. The relation between the ECG findings in heat stroke and the clinical outcomes of these patients has not been studied. The aim of this study was to describe the electrocardiographic features in patients with classic heat stroke and to determine if there is any correlation of ECG findings with in-hospital outcomes.

METHODS: We performed a retrospective study on 50 patients with classic heat stroke during summer months of 2016-2018. All 12-lead electrocardiographic recordings obtained from these patients were subjected to in-depth analysis. Statistical analysis was done to determine the correlation of electrocardiographic findings with in-hospital outcomes.

RESULTS: 37 patients were in sinus rhythm, while supraventricular arrhythmias including atrial fibrillation (n=6), ectopic atrial tachycardia (n=4) and atrial flutter (n=2) were observed in the rest. There was a high prevalence of QTc prolongation, low voltage P waves, conduction defects like incomplete right bundle branch block and repolarisation abnormalities. The ratio of QRS voltage in the limb leads to that in precordial leads was ≤0.5 in nearly three-fourths of the patients. Among the observed electrocardiographic features, low P-wave voltage (<0.01 mV) in lead II was found to have statistically significant correlation with adverse in-hospital outcome (OR 8.93, p=0.04), after adjustment for clinical covariates.

CONCLUSION: There was high incidence of atrial arrhythmias in patients with classic heat stroke. A low P-wave voltage (<0.01 mV) in lead II was predictive of adverse in-hospital outcome in this cohort of patients.

Keywords: atrial arrhythmias; classic heat stroke; electrocardiography; heart; hyperthermia

Conflict of interest statement

References

1. J Am Coll Cardiol. 2001 Jul;38(1):219-26 - PubMed
2. N Engl J Med. 2002 Jun 20;346(25):1978-88 - PubMed
3. Prog Cardiovasc Dis. 1964 Sep;7:115-24 - PubMed
4. Int J Cardiol. 1992 Nov;37(2):151-4 - PubMed
5. Int Heart J. 2005 May;46(3):543-50 - PubMed
6. Crit Care Med. 2006 Apr;34(4):1087-92 - PubMed
7. Am Heart J. 2006 Aug;152(2):355-61 - PubMed
8. J Electrocardiol. 2008 Jul-Aug;41(4):281-6 - PubMed
9. Age Ageing. 2010 Mar;39(2):245-52 - PubMed
10. Mil Surg. 1946 Nov;99(5):397-449 - PubMed
11. Ann Emerg Med. 2012 Jul;60(1):63-6 - PubMed
12. J Saudi Heart Assoc. 2012 Jan;24(1):35-9 - PubMed
13. J Emerg Med. 2015 Jan;48(1):31-4 - PubMed
14. Am J Med. 1986 Nov;81(5):795-800 - PubMed
15. J Electrocardiol. 1985 Jan;18(1):35-40 - PubMed
16. Am Heart J. 1968 Oct;76(4):514-25 - PubMed
17. Int J Cardiol. 1995 Jan 6;47(3):297-300 - PubMed
18. Am Fam Physician. 1994 Aug;50(2):389-96, 398 - PubMed
19. Chest. 1993 Aug;104(2):411-4 - PubMed
20. JACEP. 1976 Jul;5(7):525-8 - PubMed

Publication Types

• Journal Article