Spectrum of cardiac involvement in patients with dengue fever

Highlights

• Cardiac involvement is not rare in patients with dengue fever.

• Most common cardiac dysfunction is sinus bradycardia.

• Rising serum levels of markers of cardiac injury is indicative of bad prognosis.

• Patients with left ventricular dysfunction should be looked for by echocardiography.

• Abnormalities in either ECHO or ECG or elevated serum levels of markers of cardiac injury are predictors of risk for adverse outcome.

• Lack of ECG and ECHO abnormalities and normal serum levels of markers of cardiac injury has a 100% negative predictive value.

Abstract

Background

Dengue fever (DF) is an infectious disease of viral origin common in the tropics. Studies on a large number of patients with dengue infection to assess associated cardiac involvement are rare.

Methods

We analyzed the incidence and spectrum of cardiac abnormalities in 320 patients with dengue fever admitted to our hospital located in an endemic area for dengue infection. All patients were evaluated following the WHO guidelines. Those confirmed to have dengue infection by serology had detailed clinical evaluation, 12‑lead electrocardiography (ECG), assay for cardiac markers (troponin T, CK-MB, NT Pro BNP) and 2-D echocardiography.

Results

Among the 320 patients selected for the study 112 (35%) had changes of cardiac involvement as detected by investigations. Changes in ECG were seen in all of them. Sinus bradycardia in spite of fever was the most common abnormality (n = 63;19.7%). Forty-two (13.1%) patients had left ventricular ejection fraction less than 40%. Forty-eight patients (15%) had increased serum levels of troponin-T. Serum levels of CK-MB were elevated in 34 (10.6%) and serum levels of NT-pro BNP was increased in 19 (5.9%). Fourteen patients died and all of them had abnormalities in electrocardiogram, echocardiogram and serum markers.

Conclusion

Our study reveals that cardiac involvement in patients with dengue infection is not uncommon. We found that ECHO or ECG abnormalities or elevated serum levels of markers of cardiac injury are predictors of risk for adverse outcome. Absence of these abnormalities has a 100% negative predictive value.

Introduction

Dengue infection is one of the common tropical infectious diseases. It is a rapidly spreading mosquito-borne arboviral infection of humans and has a wide spectrum of presentations ranging from uncomplicated self-limiting febrile illness to dengue hemorrhagic fever (DHF) with severe hemorrhagic manifestations and dengue shock syndrome (DSS) with multi organ involvement [1]. With increasing incidence of dengue fever, reports of atypical manifestations are on the rise; these may be under reported because of lack of awareness and under-diagnosis [2].

Cardiac involvement is not uncommon and is encountered in Centers handling large numbers of patients with dengue infection. Clinical manifestations of cardiac involvement can vary widely, from an incidental finding to severe cardiac failure resulting in death [3]. Dengue fever affecting the heart can lead to cardiac arrhythmias and left ventricular dysfunction [4]. There is limited information on the incidence and spectrum of cardiac disorders in patients with dengue infection. Our knowledge is based on case reports [[5], [6], [7]], and studies on samples of 11 to 16 patients evaluated during dengue epidemics. Prevalence of cardiac involvement reported in these studies varies from 9 to 15% [[8], [9], [10]]. A study on cardiac involvement in a large population of patients with dengue fever is significant for better understanding of dengue infection and would potentially improve management of this illness.

In this report, we present the incidence and spectrum of cardiac involvement in patients with dengue fever admitted during one year in our hospital, a tertiary care multispecialty hospital in an area endemic for dengue infection. Our study has identified predictors of risk for adverse outcome in patients with dengue fever and cardiac involvement. The absence of ECG and ECHO abnormalities and normal serum levels of markers of cardiac injury have a 100% negative predictive value. These patients may not require the level of monitoring and care as required by patients with abnormalities in these investigations.

Our study was conducted during a period of 1 year from September 2016 to August 2017. Ethical committee clearance for the study was obtained from the Institutional Human Ethics Committee. All patients above 18 years of age with a confirmed diagnosis of dengue fever admitted to our hospital during the study period and who gave a written consent to participate in the study were enrolled. For critically ill patients, informed consent was obtained from their immediate relatives or legal guardians. Patients with preexisting coronary artery disease, heart failure, left ventricular dysfunction, valvular heart disease, cardiomyopathy, cardiac arrhythmias or pre-existing kidney dysfunction with serum creatinine >1.5 mg/dl were excluded.