Myocardial depression in dengue hemorrhagic fever: prevalence and clinical description

Complete atrioventricular block-an uncommon clinical presentation in an adult patient with proven dengue fever

Dengue is a viral disease that clinically presents with fever, thrombocytopenia-related haemorrhagic complications and shock in its severest form. This female patient in her 40s primarily presented to the emergency department of the cardiac centre as syncopal attacks with a complete atrioventricular block. Temporary cardiac pacing as an emergency procedure helped to maintain cardiac rhythm and haemodynamics. A history of recent onset fever helped us to suspect and confirmed by serology for dengue pathology. Normal sinus rhythm was restored after 2 days, and we removed the temporary pacing. Cardiac arrhythmia did not recur in 6 months of follow-up. The aetiology for dengue-related cardiac arrhythmia is still not established. In the recovery phase from fever, complete heart block may show up as a primary presentation in the emergency. Its timely diagnosis and temporary pacing may allow spontaneous recovery. The inclusion of electrocardiography in dengue patient guidelines should help clinicians to dictate its treatment.

Association of Neutrophil Mediators With Dengue Disease Severity and Cardiac Impairment in Adults

BACKGROUND

Cardiac impairment contributes to hypotension in severe dengue (SD). However, studies examining pathogenic factors affecting dengue-associated cardiac impairment are lacking. We examined the role of neutrophil mediators on cardiac impairment in clinical dengue.

METHODS

We prospectively enrolled adult patients with dengue and controls. Cardiac parameters were measured using a bioimpedance device. Neutrophils mediators were measured, including myeloperoxidase (MPO) and citrullinated histone H3.

RESULTS

We recruited 107 dengue patients and 30 controls. Patients with dengue were classified according to World Health Organization 2009 guidelines (44 with dengue fever [DF], 51 with DF with warning signs, and 12 with SD). During critical phase, stroke index (P < .001), cardiac index (P = .03), and Granov-Goor index (P < .001) were significantly lower in patients with dengue than in controls. During critical phase, MPO was significantly higher in patients with dengue than in controls (P < .001) and also significantly higher in patients with SD than in those with DF. In addition, MPO was inversely associated with the stroke, cardiac, and Granov-Goor indexes, during the critical phase, and longitudinally as well.

CONCLUSIONS

Cardiac function was decreased, and MPO increased, during with critical phase in patients SD compared with those with DF and controls. MPO may mediate dengue-associated cardiac impairment.

Heart Disease and Arboviruses: A Systematic Review and Meta-Analysis

Dengue fever, chikungunya, and zika are highly prevalent arboviruses transmitted by hematophagous arthropods, with a widely neglected impact in developing countries. These diseases cause acute illness in diverse populations, as well as potential cardiovascular complications. A systematic review was carried out to investigate the burden of cardiac involvement related to these arboviruses. Multiple databases were searched for articles that investigated the association of cardiovascular diseases with arboviruses, published up to March 2022. Relevant articles were selected and rated by two independent reviewers. Proportion meta-analysis was applied to assess the frequency-weighted mean of the cardiovascular findings. A total of 42 articles were selected (n = 76,678 individuals), with 17 manuscripts on dengue and 6 manuscripts on chikungunya undergoing meta-analysis. The global pooled incidence of cardiac events in dengue fever using a meta-analysis was 27.21% (95% CI 20.21–34.83; I² = 94%). The higher incidence of dengue-related myocarditis was found in the population younger than 20 years old (33.85%; 95% CI 0.00–89.20; I² = 99%). Considering the studies on chikungunya (n = 372), the global pooled incidence of cardiac involvement using a meta-analysis was 32.81% (95% CI 09.58–61.49, I² = 96%). Two Zika studies were included that examined cases of infection by vertical transmission in Brazil, finding everything from structural changes to changes in heart rate variability that increase the risk of sudden death. In conclusion, cardiac involvement in arboviruses is not uncommon, especially in dengue fever.

Cardiovascular sequelae of dengue fever: a systematic review

BACKGROUND

: Dengue is the most important viral diseases globally and a majority of symptomatic infections result in a benign course. However, a small number of patients develop severe manifestations, including myocardial impairment, arrhythmias, and fulminant myocarditis.

AREAS COVERED

This review outlines the incidence of cardiovascular (CV) manifestations of dengue. Electronic databases, including PubMed/MEDLINE, EMBASE, Scopus, and CINAHL were searched for articles incorporating cardiac manifestations of dengue fever (DF).

EXPERT OPINION

: Included studies involved 6,773 patients and 3,122 (46.1%) exhibited at least one cardiac manifestation with DF. Electrocardiogram (ECG) abnormalities (30.6%) included sinus bradycardia (8.8%), non-specific ST-T changes (8.6%), ST depression (7.9%), and T-wave inversion (2.3%). Mechanical sequelae were present in 10.4%, including left ventricular (LV) systolic dysfunction (5.7%), and myocarditis (2.9%). Pericardial involvement was noted as pericarditis (0.1%), pericardial effusion (1.3%), and pericardial tamponade (0.1%). Apart from that, the cardiac injury was depicted through a rise in cardiac enzymes (4.5%). The spectrum of CV manifestations in dengue is broad, ranging from subtle ST-T changes to fulminant myocarditis. This can be a cause of hemodynamic collapse during the critical phase of capillary leakage. Use of contemporary techniques in diagnosing cardiac involvement should be employed for rapid diagnosis and treatment in DF.

Characteristics of hemodynamic parameters after fluid resuscitation and vasoactive drugs administration in pediatric shock: A prospective observational study

Background

Prior studies have shown that septic shock survivors had a normal cardiac index (CI) and systemic vascular resistance index (SVRI). However, this feature seems to be questionable in other-caused shock, since several factors are associated with the hemodynamic profile. This study aims to describe hemodynamic profiles (preload, inotropy, afterload, stroke volume, and cardiac output) after fluid resuscitation and vasoactive therapy in children with shock.

Methods

Children aged 1 month to 18 years old with shock conditions were included in this study. Fluid resuscitation was administered following the American College of Critical Care Medicine (ACCM) protocol. Hemodynamic profiles were assessed at 1 and 6 h from the start of fluid resuscitation. Grouping of the subjects was determined by the USCOM examination in 1st hour until the end of the study and we divided into 3 groups.

Results

At 1 h, group 1 (low CI) was 14% (CI:2.5[1.2–3.2]L/min/m²), group 2 (normal CI) was 66% (CI:4.2[3.4–5.8]L/min/m²), and group 3 (high CI) was 20% (CI:7.1[6.1–9.4]L/min/m²). SVRI was higher in groups 1 and 2 compared to group 3 (p < 0.05). Group 1 and 2 revealed fluid-refractory shock (SVV:25[12–34]% and 29(13–58)%, respectively), lower Smith-Madigan Inotropy Index (SMII) and higher Potential to Kinetic Ratio (PKR) compared to group 3 (p < 0.05). Group 3 revealed fluid-responsive shock (Stroke Volume Variation (SVV):32[18–158]%), higher SMII and lower PKR. At 6th hour, CI in all groups were normal (group 1:3.5[1.2–7.5]; group 2:4.0[1.7–6.1]; group 3:6.0[3.1–6.2]). However, 71.4% and 54.5% of subjects in groups 1 and 2, respectively, still revealed low inotropy. Group 3 revealed a significant increase in SVRI and PKR (p < 0.01).

Conclusions

Most pediatric shock patients were hypodynamic. Even when the CI was normal, the preload, inotropy, and afterload may still be abnormal. It represented the inotropy as a key to hemodynamic.

•

Describe the macrocirculation parameter (preload, inotropy, afterload) in children with shock.

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Most pediatric shock tend to be hypodynamic.

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Fluid and vasoactive agent therapy should be guided by combination of the hemodynamic parameters.

Cardiac evaluation in adults with dengue virus infection by serial echocardiography

Background

Dengue virus infection (DVI) is a major health problem in many parts of the world. Its manifestations range from asymptomatic infections to severe disease. Although cardiac involvement has been reported in DVI, its incidence has not yet been well established.

Methods

From July 2016 to January 2018, patients hospitalized at the Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, Thailand, with dengue virus infection confirmed by positive NS1 or positive dengue immunoglobulin M findings, participated in the study. We characterized the incidence and change in cardiac function by serial echocardiography and levels of troponin-T and creatine kinase-myocardial band (CK-MB) on the day of admission, the day of defervescence, the first day of hypotension (if any), and at 2 week follow-up.

Results

Of the 81 patients evaluated, 6 (7.41%) exhibited elevated biomarker levels. There was no difference in clinical presentation amongst dengue fever, dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS), except for the amount of bleeding. Cardiac involvement was found in 22.2% of patients: 3 (3.70%) had left ventricular systolic dysfunction, 3 (3.70%) had transient diastolic dysfunction, 6 (7.41%) had increased levels of at least one cardiac biomarker (troponin-T or CK-MB), and 6 (7.41%) had small pericardial effusion. Myocarditis was suspected in only two patients (with DHF); thus, myocarditis was uncommon in patients with dengue virus infection. Three patients developed DSS during admission and were transferred to the intensive care unit.

Conclusion

Cardiac involvement in adults with dengue infection was common, ranging from elevated cardiac biomarker to myocarditis. Abnormalities in cardiac function had resolved spontaneously by the day of follow-up, without specific treatment. We found that DHF was a significant risk factor for cardiac involvement. Echocardiography is the investigation of choice for evaluating the haemodynamic status of patients with DVI, especially in severe dengue.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06639-x.

Dengue hemorrhagic fever and cardiac involvement

Dengue viral infection (DVI) is one of the world’s most significant viral infections spreading. Most of the patients have been asymptomatic, with relatively benign clinical manifestations and outcomes. However, a small number of patients have progressed to severe dengue diseases, including hemorrhage, multi-organ impairment, and increased vascular leakage causing hypovolemic shock, which can cause cardiovascular collapse and death. Numerous lines of evidence have demonstrated that DVI could also cause cardiac dysfunction, arrhythmias, and severe myocarditis. The treatment for dengue hemorrhagic fever (DHF) patients remains symptomatic and supportive, with close monitoring of hemodynamic status. The contributory role of cardiac dysfunction in DHF patients has potentially critical implications on the management. This review will address the current knowledge of cardiac involvement in DHF patients and the management strategy to reduce the fatality outcome.

Incidence of Cardiac Manifestations in Children with Dengue Fever: A Cross-sectional Study

OBJECTIVE

The aim of our study was to explore the incidence of cardiac involvement in children with dengue infection admitted in a tertiary care hospital and to evaluate the features of cardiac involvement with the severity of dengue fever.

METHODS

This was a cross-sectional study conducted from September 2014 to August 2016. A total of 130 patients with confirmed dengue NS1 antigen or IgM antibody positivity between the ages of 1 month and 18 years were evaluated. On the third day of admission, blood samples for cardiac markers were collected, and electrocardiograms (ECG) and echocardiograms were performed for each patient.

RESULTS

Of the 130 dengue patients in the study, 60 (46.2%) were males and 70 (53.8%) were females (male to female ratio, 1:1.16). Cardiac involvement was present in 60 (46.2%) children and was more prominent in children with severe dengue (72.7%), followed by dengue with warning symptoms (53.8%) and dengue fever (28.6%). There was no significant correlation between cardiac involvement and primary/secondary dengue. Both ECG and echocardiography changes were significantly correlated with dengue severity, as opposed to cardiac markers.

CONCLUSIONS

Cardiac involvement was present in children with dengue. Evaluation with ECG, echocardiography, and cardiac markers such as creatine phosphokinase-myocardial band (CPK-MB) are required for the management of cardiac complications in children with dengue. Our study showed an association between cardiac involvement and the severity of dengue. Further studies should be framed, and follow-up of dengue patients with cardiac involvement is necessary for therapeutic management.

Spectrum of cardiac involvement in patients with dengue fever

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.

Myocarditis in admitted patients with dengue fever

PURPOSE

Cardiac involvement in dengue fever is underdiagnosed due to low index of clinical suspicion and its contribution to hemodynamic instability in severe dengue is not well known.

METHODS

A prospective observational study was conducted among admitted patients ≥ 14 years of age having confirmed dengue fever. Patients on medications affecting heart rhythm/rate, pre-existing heart disease and electrolyte abnormalities were excluded. A baseline electrocardiography (ECG), Trop-I and NT-proBNP were done for all patients. The biomarkers were measured using enzyme-linked fluorescent assay and recommended cut-off were used. Patients with elevated biomarkers underwent 2-dimensional echocardiography. Diagnosis of myocarditis was as per European Society of Cardiology (ESC) 2013 criteria.

RESULTS

A total of 182 patients were recruited with mean age of 30 ± 12.6 years and 31% were females. Dengue with warning signs was present in 85 (47%) and severe dengue in 60 (33%) patients. ECG abnormalities were observed in 44 (24%) patients, biomarkers were elevated in 27 (15%) patients and 11 (6%) patients had echocardiographic abnormalities. According to ESC 2013 criteria, dengue fever with myocarditis was diagnosed in 13 [7.1% (95% CI 3.4-10.9)] patients. The patients with myocarditis were more likely to have shortness of breath, bleeding manifestations and higher respiratory rate at baseline. Clinical features of fluid overload were more common (69% vs. 1.7%, p < 0.01) and the duration of hospital stay longer in myocarditis group (7 ± 4.3 vs. 4.8 ± 1.9 days, p < 0.01).

CONCLUSION

Myocarditis among admitted dengue patients is not uncommon and may lead to increased morbidity.

Myocarditis Prevalence in Paediatric Dengue Infection: A Prospective Study in Tertiary Hospital in Yogyakarta, Indonesia

Awareness of cardiac involvement in dengue infection has potentially valuable management implications. To determine the prevalence of myocarditis in dengue severity, we conducted prospective study of paediatric dengue illness at Dr. Sardjito General Hospital, a tertiary hospital in Yogyakarta, Indonesia, from period of July 2015 to May 2016. World Health Organization (WHO) Dengue Guideline 2011 classification system was used. Diagnosis of dengue infection was made based on either by dengue serology and/or NS1 test. Myocarditis was assessed based on elevation of cardiac enzymes, as creatine kinase (CK), creatine kinase-MB (CK-MB), Troponin I (TnI) and by electrocardiography (ECG). Proportion between groups was compared using the Fisher's exact test. We analysed 50 children with diagnosis of dengue fever (DF), 12 of dengue haemorrhagic fever (DHF) and 23 of dengue shock syndrome (DSS). Myocarditis diagnosed in 53%, 75% and 96% of DF, DHF and DSS, respectively. We found that myocarditis was more prevalent significantly in DSS than DF (p = 0.003).

Beyond thrombocytopaenia, haemorrhage and shock: the expanded dengue syndrome

Dengue infection classically presents with fever, thrombocytopaenia, and varying degrees of plasma leakage, giving rise to shock. However, a myriad of other manifestations, involving the cardiovascular system, the nervous system, the liver, the kidneys, the gut and the haematological system have been reported in dengue. This review summarizes these varied presentations.

Development of standard clinical endpoints for use in dengue interventional trials

Dengue is a major public health problem worldwide. Although several drug candidates have been evaluated in randomized controlled trials, none has been effective and at present, early recognition of severe dengue and timely supportive care are used to reduce mortality. While the first dengue vaccine was recently licensed, and several other candidates are in late stage clinical trials, future decisions regarding widespread deployment of vaccines and/or therapeutics will require evidence of product safety, efficacy and effectiveness. Standard, quantifiable clinical endpoints are needed to ensure reproducibility and comparability of research findings. To address this need, we established a working group of dengue researchers and public health specialists to develop standardized endpoints and work towards consensus opinion on those endpoints. After discussion at two working group meetings and presentations at international conferences, a Delphi methodology-based query was used to finalize and operationalize the clinical endpoints. Participants were asked to select the best endpoints from proposed definitions or offer revised/new definitions, and to indicate whether contributing items should be designated as optional or required. After the third round of inquiry, 70% or greater agreement was reached on moderate and severe plasma leakage, moderate and severe bleeding, acute hepatitis and acute liver failure, and moderate and severe neurologic disease. There was less agreement regarding moderate and severe thrombocytopenia and moderate and severe myocarditis. Notably, 68% of participants agreed that a 50,000 to 20,000 mm³ platelet range be used to define moderate thrombocytopenia; however, they remained divided on whether a rapid decreasing trend or one platelet count should be case defining. While at least 70% agreement was reached on most endpoints, the process identified areas for further evaluation and standardization within the context of ongoing clinical studies. These endpoints can be used to harmonize data collection and improve comparability between dengue clinical trials.

Dengue is a major public health problem worldwide. Although several drug candidates have been evaluated in randomized controlled trials, none has been effective, and early recognition of severe dengue and timely supportive care remain the only means to reduce mortality. While the first dengue vaccine was recently licensed, and several other candidates are in late stage clinical trials, future decisions regarding deployment of such vaccines or therapeutics will require evidence of product safety, efficacy and effectiveness. Standard, quantifiable clinical endpoints are needed to ensure reproducibility and comparability of research findings. To address this need, we established a working group of dengue researchers, vaccine developers, and public health specialists to develop endpoints. After two working group meetings and discussions at international meetings, the Delphi methodology was used to clarify and further develop endpoints such that 70% or greater agreement was reached on most endpoint definitions including moderate and severe plasma leakage, moderate and severe bleeding, acute hepatitis and acute liver failure, and moderate and severe neurologic disease. The process identified areas for further evaluation and standardization within the context of ongoing clinical studies. The endpoints can be used to harmonize data collection and improve comparability between dengue clinical trials.

Elevated cardiac biomarkers and echocardiographic left ventricular dysfunction at admission in patients with dengue fever: report from a tertiary care center in Northwest India

Cardiac involvement is not an uncommon manifestation in dengue fever and diagnosing it has always been a challenge to physicians owing to its constellation of clinical features and lack of standard screening methods. We studied the prevalence of cardiac involvement among fifty sequential adult patients of dengue fever admitted in our emergency department, PGIMER, Chandigarh, India, who were assessed clinically and classified based on the severity. They were studied for possible cardiac involvement by means of point-of-care testing for serum cardiac biomarkers (quantitative troponin-I, creatinine kinase - MB Isoform and cardiac myoglobin) and two-dimensional transthoracic echocardiogram (2D-echo). Evidence of myocardial involvement was present in 16% and 30% patients based on 2D-echo and biomarker testing respectively. On univariate analysis, the presence of cardiac symptoms (p = 0.009) and of shock (p = 0.003) showed statistically significant association with biomarker elevation. However, this and evidence of myocardial dysfunction by 2-D echo showed poor inter-correlation.

Dengue Perimyocarditis: A Case Report

Dengue is the most important mosquito borne viral disease in the world. It is endemic in South and Southeast Asia, Central and Latin America, and Africa. One of its manifestations is dengue shock syndrome (DSS), a medical emergency with a very high mortality. Cardiac involvement is a known but infrequent feature of dengue. Cardiac dysfunction may complicate management of hypotension in DSS. We report a case of a 16-year-old male presenting with fulminant DSS as well as perimyocarditis that both confounded the clinical picture and complicated the clinical management.

Análisis descriptivo del compromiso de órganos en niños con dengue grave en Neiva, Colombia

Introducción. La infección por dengue puede comprometer órganos como el miocardio y el hígado. Tal hecho puede agravar la evolución clínica, por ello estos órganos han sido considerados en la clasificación revisada de la Organización Mundial de la Salud (OMS) para esta enfermedad.Objetivo. Describir la presencia de afectación por dengue en órganos como miocardio, hígado y sistema nervioso central (SNC) en niños de Neiva, ColombiaMateriales y métodos. Este estudio analizó 930 niños con diagnóstico de dengue confirmado que ingresaron al Hospital Universitario Hernando Moncaleano Perdomo de Neiva entre enero de 2009 y diciembre de 2010. Para el diagnóstico y estratificación clínica se usó la clasificación revisada de la OMS. La infección por dengue se confirmó por detección plasmática de NS1 o IgM específica. Se realizó seguimiento clínico y paraclínico diario durante toda la hospitalización.Resultados. De los 930 niños, 105 fueron clasificados como dengue grave (DG) y, de estos, 19 presentaron órganos afectados. El miocardio fue el más comprometido (14 casos), seguido por el hígado (4 casos) y el SNC (1 caso).Conclusión. El compromiso clínico del miocardio, el hígado o el SNC se observó en el 18% de los casos de niños con DG. Es necesario un diagnóstico y tratamiento oportuno de esta patología en niños.

Cardio-haemodynamic assessment and venous lactate in severe dengue: Relationship with recurrent shock and respiratory distress

Background

Dengue can cause plasma leakage that may lead to dengue shock syndrome (DSS). In approximately 30% of DSS cases, recurrent episodes of shock occur. These patients have a higher risk of fluid overload, respiratory distress and poor outcomes. We investigated the association of echocardiographically-derived cardiac function and intravascular volume parameters plus lactate levels, with the outcomes of recurrent shock and respiratory distress in severe dengue.

Methods/Principle findings

We performed a prospective observational study in Paediatric and adult ICU, at the Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam. Patients with dengue were enrolled within 12 hours of admission to paediatric or adult ICU. A haemodynamic assessment and portable echocardiograms were carried out daily for 5 days from enrolment and all interventions recorded.

102 patients were enrolled; 22 patients did not develop DSS, 48 had a single episode of shock and 32 had recurrent shock. Patients with recurrent shock had a higher enrolment pulse than those with 1 episode or no shock (median: 114 vs. 100 vs. 100 b/min, P = 0.002), significantly lower Stroke Volume Index (SVI), (median: 21.6 vs. 22.8 vs. 26.8mls/m², P<0.001) and higher lactate levels (4.2 vs. 2.9 vs. 2.2 mmol/l, P = 0.001). Higher SVI and worse left ventricular function (higher Left Myocardial Performance Index) on study days 3–5 was associated with the secondary endpoint of respiratory distress. There was an association between the total IV fluid administered during the ICU admission and respiratory distress (OR: 1.03, 95% CI 1.01–1.06, P = 0.001). Admission lactate levels predicted patients who subsequently developed recurrent shock (P = 0.004), and correlated positively with the total IV fluid volume received (rho: 0.323, P = 0.001) and also with admission ALT (rho: 0.764, P<0.001) and AST (rho: 0.773, P<0.001).

Conclusions/Significance

Echo-derived intravascular volume assessment and venous lactate levels can help identify dengue patients at high risk of recurrent shock and respiratory distress in ICU. These findings may serve to, not only assist in the management of DSS patients, but also these haemodynamic endpoints could be used in future dengue fluid intervention trials.

Dengue is a viral illness that can lead to severe and potentially fatal complications. The most common complication is fluid leakage from blood vessels, which can cause low blood pressure or dengue shock syndrome (DSS). The majority of patients recover with simple intravenous fluid replacement, however in approximately 30% of DSS cases, recurrent episodes of shock occur, and these patients have a higher risk of fluid overload, respiratory distress and death. We investigated whether using portable echocardiograms (Echo) in the intensive care unit (ICU) to assess cardiac function and intravascular volume parameters as well as blood lactate levels, can help identify these patients. We found patients who developed recurrent shock had higher heart rates and lower Stroke Volume Index (SVI), and higher lactate levels at enrolment than those with 1 episode or no shock. Higher SVI and worse cardiac function after 3 days in ICU was associated with respiratory distress. Admission lactate levels predicted patients who subsequently developed recurrent shock and correlated positively with the total IV fluid volume received. These results demonstrate that Echo-derived intravascular volume assessment and venous lactate levels can help identify dengue patients at high risk of poor outcomes in the ICU, and could assist in the management of severe dengue.

Current management of severe dengue infection

INTRODUCTION

Traditionally a disease mainly affecting the pediatric population, dengue burden has increased significantly in recent decades and adults with severe disease may become more common. There is currently no effective anti-viral agent available for the treatment of dengue and supportive care is the mainstay of management. Areas covered: We present a review of current literature on dengue severity classification systems and the management of severe dengue in adults. In particular, emphasis was placed on organ impairment in dengue and management of elderly individuals with multiple medical problems. Expert commentary: There is an urgent need to search for an effective anti-viral agent to treat infected individuals. The commercial availability of a dengue vaccine in older children has provided optimism in reducing the disease burden but long term efficacy and safety are unknown. The results from phase III trials of two new candidate vaccines are eagerly awaited.

Complete Heart Block in Association with Dengue Hemorrhagic Fever

Dengue virus infection affects the heart structurally and functionally. Clinical manifestations of cardiac complications secondary to dengue virus infection vary from self-limiting arrhythmias to severe myocardial infarction, leading to hypotension, pulmonary edema, and cardiogenic shock. However, we report a case of dengue hemorrhagic fever (DHF) complicated by a complete heart block. A female with DHF due to dengue virus serotype 2, presented to the emergency department with fever, headache, rash, and fatigue followed by an episode of syncope. She was found to have a third-degree atrioventricular block, with pulseless polymorphic ventricular tachycardia. Patient was resuscitated and a temporary trans-venous pacemaker was placed. She reverted back to normal sinus rhythm after 4 days of syncope and was subsequently discharged from the hospital after complete resolution of symptoms, without the need for a permanent pacemaker. Physicians are warranted to have high index of suspicion for dengue virus infection as an etiology in patients with acute cardiovascular compromise, especially in tropical areas.

Evaluation of Cardiac Involvement in Children with Dengue by Serial Echocardiographic Studies

Background

Infection with dengue virus results in a wide range of clinical manifestations from dengue fever (DF), a self-limited febrile illness, to dengue hemorrhagic fever (DHF) which is characterized by plasma leakage and bleeding tendency. Although cardiac involvement has been reported in dengue, the incidence and the extent of cardiac involvement are not well defined.

Methods and Principal findings

We characterized the incidence and changes in cardiac function in a prospective in-patient cohort of suspected dengue cases by serial echocardiography. Plasma leakage was detected by serial chest and abdominal ultrasonography. Daily cardiac troponin-T levels were measured. One hundred and eighty one dengue cases were enrolled. On the day of enrollment, dengue cases that already developed plasma leakage had lower cardiac index (2695 (127) vs 3188 (75) (L/min/m²), p = .003) and higher left ventricular myocardial performance index (.413 (.021) vs .328 (.026), p = .021) and systemic vascular resistance (2478 (184) vs 1820 (133) (dynes·s/cm⁵), p = .005) compared to those without plasma leakage. Early diastolic wall motion of the left ventricle was decreased in dengue cases with plasma leakage compared to those without. Decreased left ventricular wall motility was more common in dengue patients compared to non-dengue cases particularly in cases with plasma leakage. Differences in cardiac function between DF and DHF were most pronounced around the time of plasma leakage. Cardiac dysfunction was transient and did not require treatment. Transient elevated troponin-T levels were more common in DHF cases compared to DF (14.5% vs 5%, p = 0.028).

Conclusions

Transient left ventricular systolic and diastolic dysfunction was common in children hospitalized with dengue and related to severity of plasma leakage. The functional abnormality spontaneously resolved without specific treatment. Cardiac structural changes including myocarditis were uncommon.

Dengue is a viral infection with a wide range of symptoms from a self-limiting fever called dengue fever (DF) to dengue hemorrhagic fever (DHF) which is characterized by leaky blood vessels and bleeding that can lead to shock in severe cases. Abnormal heart function has been reported but the frequencies and the progression of heart involvement are not well defined. In this study children with dengue had serial evaluation of their heart function during the course of the illness. Patients with DHF had comparatively low blood volume at the time of fever resolution and had decreased blood flow into the left lower heart chamber compared to DF cases. Relaxation and contraction of the left side of the heart were also relatively decreased in DHF. These abnormalities may contribute to the clinical response and complications of fluid replacement in dengue.

Cardiovascular manifestations of the emerging dengue pandemic

Dengue is one of the most important emerging viral diseases globally. The majority of symptomatic infections result in a relatively benign disease course. However, a small proportion of patients develop severe clinical manifestations, including bleeding, organ impairment, and endothelial dysfunction with increased capillary permeability causing hypovolaemic shock that can lead to cardiovascular collapse. Evidence is increasing that dengue can also cause myocardial impairment, arrhythmias and, occasionally, fulminant myocarditis. No antiviral agents or vaccines are licensed for dengue, and treatment remains supportive with judicious fluid replacement for patients with severe disease. Defining the role of cardiac dysfunction in the haemodynamic compromise of severe dengue has potentially important management implications. In this Review, we will outline the current understanding of the cardiovascular manifestations of dengue, including myocardial and vascular involvement, and conclude with a discussion of the available therapeutic options and potential future research directions.

Evaluation of sublingual microcirculation in children with dengue shock

OBJECTIVE

To report the sublingual microcirculation observed using Sidestream Dark Field imaging in two children with dengue shock.

METHOD

Two children, aged 9 and 10 years, were admitted to the pediatric intensive care unit with dengue shock and multiple organ dysfunction. Sublingual microcirculation was assessed in each patient on the first and second days of shock and was assessed a final time when the patients were no longer in shock (on the day prior to extubation) using Sidestream Dark Field technology. The De Backer score and microvascular flow index were used for the analyses.

RESULTS

Both patients had reduced perfused small vessel density in the first two days and showed predominantly intermittent or no microcirculation flow, as demonstrated by a low microvascular flow index. The blood flow in the large vessels was not affected. Prior to the extubation, the microvascular flow index had increased, although the perfused small vessel density remained diminished, suggesting persistent endothelial dysfunction.

CONCLUSIONS

Severe microcirculation changes may be involved in the pathophysiological mechanisms that lead to the final stages of dengue shock, which is frequently irreversible and associated with high mortality rates. Microcirculatory monitoring may help elucidate the physiopathology of dengue shock and prove useful as a prognostic tool or therapeutic target.

Left ventricular myocardial performance in patients with dengue hemorrhagic fever and thrombocytopenia as assessed by two-dimensional speckle tracking echocardiography

OBJECTIVES

We obtained longitudinal, radial and circumferential strains in patients with dengue hemorrhagic fever (DhF) and thrombocytopenia using two-dimensional (2D) speckle tracking echocardiography to analyze left ventricular (LV) myocardial performance.

METHODS

In this prospective study, 2D echocardiographic images of the left ventricle in the four-, three- and two-chamber views and parasternal short-axis views at the basal, mid and apical levels were obtained in 40 subjects: 20 patients (23 ± 8 years, 12 male) with DhF and thrombocytopenia and 20 healthy controls (23 ± 5 years, 11 male). Of the 20 patients, imaging was performed again in 19 at discharge after a hospital stay of 8 ± 1 days. Longitudinal, circumferential and radial strains were quantified and compared in an 18-segment model using a novel speckle tracking system.

RESULTS

Left ventricular global ejection fraction was reduced in patients with DhF at presentation as compared with controls (51.25 ± 0.96% vs. 59.32 ± 1.26%; p = 0.032). Peak longitudinal strain in patients with DhF was significantly attenuated in the subendocardial region compared with normal controls (p < 0.001). A significant increase in circumferential strain for patients with DhF was evident only in the subepicardial region (p = 0.009). Patients with DhF showed significantly higher radial strain than controls (p < 0.001). On multivariate analysis, subendocardial longitudinal strain independently predicted the duration of hospital stay in patients with DhF.

CONCLUSION

Assessment of speckle tracking echocardiography-derived LV mechanics helps in understanding myocardial mechanics in patients with DhF and thrombocytopenia. Identification of reduced LV longitudinal strain helps in understanding the mechanism of reduced LV myocardial performance seen in patients with DhF.

High plasma levels of soluble ST2 but not its ligand IL-33 is associated with severe forms of pediatric dengue

Identification of early determinants of dengue disease progression, which could potentially enable individualized patient care are needed at present times. Soluble ST2 (sST2) has been recently reported to be elevated in the serum of children older than 2 years old and adults with dengue infection and it was correlated with secondary infections as well as with severe presentations of the disease. The mechanism by which secreted ST2 is linked to severe dengue and plasma leakage remains unclear. One possibility is that IL-33 ligand may be elevated, contributing to membrane bound ST2 as part of the immune activation in dengue infection. We determined plasma levels of sST2 and the ligand IL-33 in 66 children with acute secondary dengue infections clinically classified using the guidelines of the World Health Organization, 2009. Dengue infection showed significant increases in cytokines IL-12p70, IL-10, IL-8, IL-6, IL-1β and TNFα measured by flow cytometry based assay compared to uninfected individuals. In contrast, IL-33 levels remained unchanged between infected and uninfected individuals. The levels of sST2 positively correlated with values of IL-6 and IL-8 and inversely correlated with number of median value of platelet levels. In addition to circulating cytokine positive correlations we found that sST2 and isoenzyme creatine kinase-MB (CK-MB), a marker of myocardial muscle damage present in severe dengue cases were associated. Our pediatric study concluded that in dengue infections sST2 elevation does not involve concomitant changes of IL-33 ligand. We propose a study to assess its value as a predictor factor of disease severity.

Dengue myocarditis in Singapore: two case reports

The authors report two cases of complicated dengue viral infection with acute myocarditis involving young male adults, of which one was fatal. The first case presented with typical signs of myocardial disease: chest pain and diaphoresis with myocardial depression in the electrocardiograph. The second case deteriorated rapidly and demised within the first day of admission. Histology of the heart muscles showed multiple small foci of myocyte necrosis surrounded by lymphocytes, in keeping with viral myocarditis. Both cases fulfilled the World Health Organization (WHO) diagnosis of probable dengue: the first case had positive dengue serology, both IgM and IgG at day six of illness, and the second case was polymerase chain reaction (PCR) positive for dengue and identified as serotype 2. Despite the severe outcome, both cases did not completely fulfil the criteria for dengue haemorrhagic fever (DHF). Although severe cardiac impairment is not commonly reported in dengue infection, it can be life threatening.

Cardiac function in Vietnamese patients with different dengue severity grades

OBJECTIVE

Dengue continues to cause significant global morbidity and mortality. Severe disease is characterized by cardiovascular compromise from capillary leakage. Cardiac involvement in dengue has also been reported but has not been adequately studied.

SETTING

Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.

SUBJECTS AND DESIGN

Seventy-nine patients aged 8-6 yrs with different dengue severity grades were studied using echocardiography including tissue Doppler imaging. The patients were split into severity grades: dengue, dengue with warning signs, and severe dengue. Changes in cardiac functional parameters and hemodynamic indices were monitored over the hospital stay.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Patients with severe dengue had worse cardiac function compared with dengue in the form of left ventricular systolic dysfunction with increased left myocardial performance index (0.58 [0.26-0.80] vs. 0.38 [0.22-0.70], p = .006). Septal myocardial systolic velocities were reduced (6.4 [4.8-10] vs. 8.1 [6-13] cm/s, p = .01) as well as right ventricular systolic (11.4 [7.5-17] vs. 13.5 [10-17] cm/s, p = .016) and diastolic velocities (13 [8-23] vs. 17 [12-25] cm/s, p = .0026). In the severe group, these parameters improved from hospital admission to discharge; septal myocardial systolic velocities to 8.8 (7-11) cm/s (p = .002), right ventricular myocardial systolic velocities to 15.0 (11.8-23) cm/s, (p = .003), and diastolic velocity to 21 (11-25) cm/s (p = .002). Patients with cardiac impairment were more likely to have significant pleural effusions.

CONCLUSIONS

Patients with severe dengue have evidence of systolic and diastolic cardiac impairment with septal and right ventricular wall being predominantly affected.

Dengue shock

Shock syndrome is a dangerous complication of dengue infection and is associated with high mortality. Severe dengue occurs as a result of secondary infection with a different virus serotype. Increased vascular permeability, together with myocardial dysfunction and dehydration, contribute to the development of shock, with resultant multiorgan failure. The onset of shock in dengue can be dramatic, and its progression relentless. The pathogenesis of shock in dengue is complex. It is known that endothelial dysfunction induced by cytokines and chemical mediators occurs. Diagnosis is largely clinical and is supported by serology and identification of viral material in blood. No specific methods are available to predict outcome and progression. Careful fluid management and supportive therapy is the mainstay of management. Corticosteroids and intravenous immunoglobulins are of no proven benefit. No specific therapy has been shown to be effective in improving survival.

Dengue hemorrhagic fever and shock syndromes

OBJECTIVES

To provide a comprehensive review of dengue, with an emphasis on clinical syndromes, classification, diagnosis, and management, and to outline relevant aspects of epidemiology, immunopathogenesis, and prevention strategies. Dengue, a leading cause of childhood mortality in Asia and South America, is the most rapidly spreading and important arboviral disease in the world and has a geographic distribution of > 100 countries.

DATA SOURCE

Boolean searches were carried out by using PubMed from 1975 to March 2009 and the Cochrane Database of Systematic Reviews from 1993 to March 2009 to identify potentially relevant articles by key search terms such as: "dengue"; "dengue fever"; "dengue hemorrhagic fever"; "dengue shock syndrome"; "severe dengue" and "immunopathogenesis," pathogenesis," "classification," "complications," and "management." In addition, authoritative seminal and up-to-date reviews by experts were used.

STUDY SELECTION

Original research and up-to-date reviews and authoritative reviews consensus statements relevant to diagnosis and therapy were selected.

DATA EXTRACTION AND SYNTHESIS

We considered the most relevant articles that would be important and of interest to the critical care practitioner as well as authoritative consensus statements from the World Health Organization and the Centers for Disease Control and Prevention. Dengue viral infections are caused by one of four single-stranded ribonucleic acid viruses of the family Flaviviridae and are transmitted by their mosquito vector, Aedes aegypti. The clinical syndromes caused by dengue viral infections occur along a continuum; most cases are asymptomatic and few present with severe forms characterized by shock. Management is predominantly supportive and includes methods to judiciously resolve shock and control bleeding while at the same time preventing fluid overload.

CONCLUSIONS

Dengue is no longer confined to the tropics and is a global disease. Treatment is supportive. Outcomes can be optimized by early recognition and cautious titrated fluid replacement, especially in resource-limited environments.

Acute myocarditis in dengue hemorrhagic fever: a case report and review of cardiac complications in dengue-affected patients

We report a case of dengue hemorrhagic fever (DHF) complicated by acute myocarditis and review the literature. A 65-year-old woman experienced DHF due to dengue virus serotype 3, complicated with acute myocarditis and acute pulmonary edema. Clinically this masqueraded as acute myocardial infarction, with an electrocardiographically depressed ST segment in precordial leads and elevated serum cardiac-specific troponin I level. Under supportive management, the patient recovered 3 days later. A total of 18 pertinent articles involving 339 dengue-affected patients with cardiac complications were found by PubMed search. Clinical manifestations of cardiac complications varied considerably, from self-limiting tachy-brady arrhythmia to severe myocardial damage, leading to hypotension and pulmonary edema. Although rare, a fatal outcome was reported in some cases of dengue with cardiac complications. To avoid otherwise preventable morbidity and mortality, physicians should have a high index of suspicion for cardiac complications in patients with dengue illness and should manage this accordingly.

Outcome of dengue hemorrhagic fever-caused acute kidney injury in Thai children

OBJECTIVES

To examine the outcome of acute kidney injury (AKI) in children with dengue hemorrhagic fever (DHF), the cause(s) of AKI, and the risk of AKI and fatality.

STUDY DESIGN

The medical records of patients age <15 years during 1989 to 2007 were reviewed. DHF-caused AKI and patients with DHF with no AKI were matched 1:2 by age.

RESULTS

DHF-caused AKI was clinically estimated to be 0.9% (25/2893) of admissions, with a high mortality rate of 64.0%. Risk factors of AKI were DHF grade IV and obesity (odds ratio, 16.9; 95% CI, 4.2 to 68.5, and odds ratio, 6.3; 95% CI, 1.4 to 28.8, respectively). Respiratory failure, hepatic failure, and massive bleeding were complications found in 80.0%, 96.0%, and 84.0% of cases with AKI, respectively. Fatality was more likely in cases with DHF grade IV, oliguric AKI, respiratory failure, or prolongation of prothrombin or activated partial thromboplastin time more than twice that of reference specimens. Among the survivors, none had chronic kidney disease, and serum creatinine levels returned to normal in 32 (1 to 48) days.

CONCLUSIONS

Patients with DHF and AKI had a high mortality rate, although those who survived had a full return to normal function within 1 month. DHF grade IV and obesity were the major risk factors of AKI.