The Tei Index and Asymptomatic Myocarditis in Children With Severe Dengue

Abstract

This study aimed to assess myocardial involvement in infants and children with severe dengue (as per the new World Health Organization [WHO] classification 2009) using the Tei index. This prospective observational study was conducted in the Department of Pediatrics, PGIMER and the associated Dr. RML Hospital, New Delhi from August to December 2010. The study included 67 children (ages 3 months-14 years) who satisfied the WHO criteria for the diagnosis of probable dengue fever with warning signs or severe dengue and tested positive for dengue via immunoglobulin-M (IgM) capture enzyme-linked immunoassay (MAC-ELISA). The patients were subjected to a complete blood count, liver function tests, renal profile, electrocardiography, myocardial band enzymes of creatine phosphokinase (CPK-MB), chest x-ray, abdomen ultrasonography, and two-dimensional echocardiography with color-flow Doppler mapping. Ejection fraction and Tei index measurements were performed. Significantly fewer patients with severe dengue were found to have myocardial involvement at admission by ejection fraction (48 %) and E/E' (37 %), than by the Tei index (70 %). Of the 67 patients with severe dengue, one died, giving a case fatality rate of 1.5 %. At discharge, the Tei index persisted on the high side for patients with myocardial involvement, whereas the ejection fraction improved for the majority of them. Most of the patients with severe dengue had asymptomatic myocarditis, as evident by a deranged Tei index, which improved but did not normalize by the time of discharge, necessitating a longer follow-up period. For the majority of the patients, inotropic support was not required to maintain hemodynamic stability.

Definitions for warning signs and signs of severe dengue according to the WHO 2009 classification: Systematic review of literature

“…Macedo et al did not consider having “narrow pulse pressure” alone to be defining for shock; and that shock is diagnosed in the presence of at least 2 clinical signs of hypoperfusion (eg, slow capillary refill, cold skin, and rapid and weak pulse) with or without an associated narrow pulse pressure. The authors reported 3 signs of poor capillary perfusion: slow capillary refill, cold extremities, and rapid pulse rate . Slow capillary refill was defined in 2 studies as having a capillary refill time greater than 3 seconds …”

“…Cardiac involvement as a criterion for “severe dengue” is reported in 12 studies (Table ), with most of them, 8 studies, describing it as “myocarditis.” Two studies used “heart failure” to describe cardiac involvement, while 1 study required the presence of both “myocarditis” and “heart failure” confirmed by echocardiography to fulfill the definition . Hoffmeister et al, however, described the cardiac involvement as “cardiomyopathy.” Except for Lovera et al and Guerrero et al, none of the above mentioned studies reported on the diagnostic criteria for heart failure, cardiomyopathy, or myocarditis.…”

Cardiac Manifestations in Dengue Fever: A Cross Sectional Study From a Tertiary Care Centre of North India

“…The prevalence of subclinical diastolic dysfunction has been reported to increase with age, in individuals with hypertension, LV hypertrophy, and diabetes so these were already excluded from the study. [22][23][24][25][26] This has important implications for clinical care considering the shift in the demographics of dengue cases to adults who may have these common co-morbidities.…”

Cardiac involvement in dengue infection

“…The Tei index [50] has been suggested to be a better index of global myocardial function. Yadev et al [51] compared the sensitivity of LVEF by echo with the Tei index in a cohort of 67 children with dengue. LVEF was low in 42% of patients on admission, and low Ejection fraction (EF) was seen in half of the patients with shock.…”