Background: Dengue fever is one the most common mosquito borne viral disease. Cardiac system involvement is one of the atypical manifestations in dengue fever. So this study was conducted to find out cardiac involvement in patients Dengue fever. Also, the difference in hematological parameters in primary and secondary dengue fever was studied.

Materials and methodology: Patients admitted with dengue fever in Medicine Ward or Intensive Care Unit at Chettinad Hospital and Research institute, Kelambakkam were included in study from May 2014 to Feb 2015. Apart from routine laboratory investigations, these patients were subjected for cardiac evaluation in the form of ECG, Cardiac markers like Troponin I and ECHO.

Results: Total number of patients included in study was 60. Mean age group involvement was between  23.97± 3.6 years and males were more involved than females. Bleeding manifestations were seen in 4.5% of primary and 33.3% of secondary dengue patients, which was statistically significant (p=0.006). Leucopenia was more in patients with primary infection, 63.6% vs 22.2% in secondary (p=0.005). With regard to thrombocytopenia, all the patients with secondary dengue had low platelets, as compared to 81.8% of primary Dengue (p=0.04). Monocytosis was observed in both primary and secondary dengue fever. However, in primary dengue fever, monocytosis was found only in 33.3% of cases, whereas in secondary dengue fever it was seen in 66.7%(p=0.01). Bradycardia was the only significant cardiac manifestation found in 71.6% of patients.

Conclusion: In patients with dengue, fever with gastrointestinal symptoms and leucopenia are more likely to indicate primary infection, whereas bleeding manifestations with thrombocytopenia and monocytosis are more suggestive of secondary dengue. In our study, there was no significant cardiac involvement except bradycardia which reverted to normal after course of dengue illness.

Keywords: Dengue fever, Cardiac involvement, Leucopenia and Thrombocytopenia.