Study of Bradycardia in Dengue Fever

Abstract

BACKGROUND AND OBJECTIVES: All the four serotypes of dengue virus are found in our country. Case fatality rates in endemic countries like India are 2.5%. During epidemics of dengue, attack rates among susceptible are 40-90%. Early recognition and prompt treatment are vital if disease related morbidity and mortality are to be limited. Clinical features that can be used in the initial assessment of febrile patients are essential tools for clinicians, especially in limited resource settings. Awareness of bradycardia as a clinical finding, could help in the early recognition of dengue and potentially reduce complications and death. METHOD AND RESULTS: The study was conducted in the Department of Medicine, Mysore Medical College & Research Institute, Mysore from the period of July 2010 to December 2010 who met the inclusion and exclusion criteria. A total of 100 patients of Dengue fever were analyzed. The most common age group affected in our study was 20-39 years (53%). The clinical spectrum of cases included 22% cases of Dengue fever (DF), 72% cases of Dengue Hemorrhagic fever (DHF), 6% cases of Dengue Shock Syndrome (DSS). Clinical pulse rate distribution amongst cases showed 27% with bradycardia, 61% with relative bradycardia, and 12% with tachycardia. Electrocardiographic changes in our study showed 37% with sinus bradycardia, 48% with normal sinus rhythm, 1% with first degree heart block, and 14% with sinus tachycardia. CONCLUSION: Bradycardia was a predominant occurrence amongst total of 100 cases of Dengue fever analyzed. 88% of the cases had bradycardia. (61% had relative bradycardia and 27% bradycardia. Majority of the patients on ECG showed sinus bradycardia (37%) and normal sinus rhythm (48%). Hence, awareness of bradycardia as a clinical finding, can help in the early recognition of dengue and potentially reduce complications and death associated with dengue virus infection.

A Cluster of Dengue Cases in Travelers: A Clinical Series from Thailand

“…A striking observation in the present study was that 80% of the patients had relative bradycardia, which was reported in up to 60% of the patients in a previous prospective study [55]. This phenomenon of relative bradycardia, known as Liebermeister's rule, has been described as occurring in several tropical diseases caused by intracellular, atypical Gram-negative bacteria, parasites, or viruses [56][57][58].…”

Study of clinico-haematological profile in dengue fever - A prospective study

“…In our study, DF was diagnosed in 69% of cases followed by DHF diagnosed in 23% of cases and DSS in 8% of cases (table no 8). In this study, pulse rate documentation demonstrates bradycardia in 39% of the cases as compared to study done by Yadav RK et al 15 where showed sinus bradycardia in 60% 0f cases and study done by Ramesh S et al 16 showed bradycardia in 27% of cases. In this study, leucopeniais seen in 53% of cases which is almost comparable with study done by Butt N et al.…”