Echocardiographic and electrocardiographic trends in children with acute Kawasaki disease

When two Z-scores meet-analysis of exercise capacity of children and adolescents with Kawasaki disease by a new Z-score model of coronary artery and a new Z-score evaluating peak oxygen consumption : Coronary artery Z-score and peakVO2 Z-score in KD

BACKGROUND

Coronary artery (CA) Z-score system is widely used to define CA aneurysm (CAA). Children and adolescents after acute stage of Kawasaki disease (KD-CA) have a higher risk of developing CAAs if their CA Z-score ≥ 2.5. Z-score system of peak oxygen consumption (Peak VO2 Z-score) allows comparisons across ages and sex, regardless of body size and puberty. We aimed to compare the exercise capacity (EC) indicated by peak VO2 Z-score during cardiopulmonary exercise testing (CPET) directly between KD-CA with different CA Z-score.

METHODS

KD-CA after acute stage who received CPET in the last 5 years were retrospectively recruited. CA Z-score was based on Lambda-Mu-Sigma method. Max-Z was the maximum CA Z-score of different CAs. KD children with Max-Z < 2.5 and ≥ 2.5 were defined as KD-1 and KD-2 groups, respectively. Peak VO2 Z-score was calculated using the equation established based on Hong Kong Chinese children and adolescent database.

RESULTS

One hundred two KD-CA were recruited (mean age: 11.71 ± 2.57 years). The mean percent of measured peak VO2 to predicted value (peak PD%) was 90.11 ± 13.33. All basic characteristics and baseline pulmonary function indices were comparable between KD-1 (n = 87) and KD-2 (n = 15). KD-1 had significantly higher peak VO2 Z-score (p = .025), peak PD% (p = .008), peak metabolic equivalent (p = .027), and peak rate pressure product (p = .036) than KD-2.

CONCLUSIONS

KD-CA had slightly reduced EC than healthy peers. KD-CA with Max-Z ≥ 2.5 had significantly lower peak EC than those < 2.5. Max-Z is potentially useful follow-up indicator after acute stage of KD.

French national diagnostic and care protocol for Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis with a particular tropism for the coronary arteries. KD mainly affects male children between 6 months and 5 years of age. The diagnosis is clinical, based on the international American Heart Association criteria. It should be systematically considered in children with a fever, either of 5 days or more, or of 3 days if all other criteria are present. It is important to note that most children present with marked irritability and may have digestive signs. Although the biological inflammatory response is not specific, it is of great value for the diagnosis. Because of the difficulty of recognising incomplete or atypical forms of KD, and the need for urgent treatment, the child should be referred to a paediatric hospital as soon as the diagnosis is suspected. In the event of signs of heart failure (pallor, tachycardia, polypnea, sweating, hepatomegaly, unstable blood pressure), medical transfer to an intensive care unit (ICU) is essential. The standard treatment is an infusion of IVIG combined with aspirin (before 10 days of fever, and for a minimum of 6 weeks), which reduces the risk of coronary aneurysms. In case of coronary involvement, antiplatelet therapy can be maintained for life. In case of a giant aneurysm, anticoagulant treatment is added to the antiplatelet agent. The prognosis of KD is generally good and most children recover without sequelae. The prognosis in children with initial coronary involvement depends on the progression of the cardiac anomalies, which are monitored during careful specialised cardiological follow-up.

Serial Exercise Testing and Echocardiography Findings of Patients With Kawasaki Disease

OBJECTIVE

Kawasaki disease (KD) is the most common form of pediatric vasculitis. We evaluated the influence of KD on cardiopulmonary function and analyzed the echocardiographic findings of patients with KD through serial follow-ups from childhood to adolescence.

METHODS

This was a retrospective study. We recruited patients with KD after the acute stage who underwent at least two (with >1-year interval between visits) cardiopulmonary exercise testing (CPET) and echocardiographic examinations in the last 10 years. Cardiopulmonary function was determined through CPET on a treadmill. The maximum Z score (Max-Z) of the proximal left anterior descending coronary artery or right coronary artery was determined using echocardiography. Healthy peers matched for age, sex, and body mass index with serial CPET and echocardiographic data were recruited as a control group.

RESULTS

Each group consisted of 30 participants with comparable basic characteristics. No significant differences in the variables of the first CPET were observed between the two groups. In the final CPET, the control group had a higher percentage of measured oxygen consumption (Vo₂) at the anaerobic threshold (AT) to the predicted peak Vo₂ (p = 0.016), higher percentage of measured peak Vo₂ to the predicted peak Vo₂ (p = 0.0004), and higher Vo₂ at AT (p < 0.0001) than those of the KD group. No significant difference in the percentage of distribution of Max-Z was observed between the first and final echocardiographic examinations.

CONCLUSIONS

Children with a history of KD had comparable exercise capacity to their healthy peers. However, in the follow-up, the aerobic metabolism and peak exercise load capacities of adolescents with KD were significantly lower than those of control adolescents.

IL-1-dependent electrophysiological changes and cardiac neural remodeling in a mouse model of Kawasaki disease vasculitis

Kawasaki disease (KD) is the leading cause of acquired heart disease in children. In addition to coronary artery abnormalities, aneurysms and myocarditis, acute KD is also associated with echocardiogram (ECG) abnormalities in 40-80% of patients. Here, we show that these ECG changes are recapitulated in the Lactobacillus casei cell wall extract (LCWE)-induced KD vasculitis mouse model. LCWE-injected mice developed elevated heart rate and decreased R wave amplitude, with significant differences in prolonged ventricular repolarization. LCWE-injected mice developed cardiac ganglion inflammation, that may affect the impulse-conducting system in the myocardium. Furthermore, serum nerve growth factor (NGF) was significantly elevated in LCWE-injected mice, similar to children with KD vasculitis, associated with increased neural remodeling of the myocardium. ECG abnormalities were prevented by blocking interleukin (IL)-1 signaling with anakinra, and the increase in serum NGF and cardiac neural remodeling were similarly blocked in Il1r1-/- mice and in wild-type mice treated with anakinra. Thus, similar to clinical KD, the LCWE-induced KD vasculitis mouse model also exhibits electrophysiological abnormalities and cardiac neuronal remodeling, and these changes can be prevented by blocking IL-1 signaling. These data support the acceleration of anti-IL-1 therapy trials to benefit KD patients.

Atypical manifestations of cardiomegaly and nephrotic syndrome in Kawasaki disease: Two case reports

RATIONALE

To examine atypical manifestations of Kawasaki disease (KD) in children.

BACKGROUND

Cardiovascular complications during acute KD are a major contributor to its mortality rate. It can involve the pericardium, the myocardium, the endocardium, and/or the coronary arteries; however, cardiomegaly and nephrotic syndrome (NS) during the acute stage of KD have seldom been reported.

PATIENT CONCERNS

Two children, each with a fever lasting more than 5 days, were diagnosed with cardiomegaly using echocardiography in the early phase of Kawasaki disease (within 2 weeks). Case 1 was misdiagnosed with NS because of the proteinuria, hypoalbuminemia, and edema present at the onset of the disease.

DIAGNOSES

A diagnosis of incomplete KD was based on a constellation of clinical manifestations and symptoms and was supported by laboratory results.

INTERVENTIONS

Intravenous immunoglobulin (IVIG) and aspirin were administered, supplemented with and without supplemental steroid therapy (case dependent).

OUTCOMES

The clinical manifestations and syndromes of the two cases were completely resolved and their heart size restored to normal within 2 weeks, with no evidence of coronary artery lesions (CAL).

MAIN LESSONS

Physical findings and manifestations are atypical in incomplete KD. Cardiomegaly and nephrotic syndrome can be an early manifestation of KD; cardiomegaly, especially, should be recognized as a possible manifestation of the acute stage of KD. Furthermore, these symptoms can be rapidly relieved by treatment with IVIG, with or without supplemental steroid therapy.

IL-1 receptor antagonist, anakinra, prevents myocardial dysfunction in a mouse model of Kawasaki disease vasculitis and myocarditis

Kawasaki disease (KD) vasculitis is an acute febrile illness of childhood characterized by systemic vasculitis of unknown origin, and is the most common cause of acquired heart disease among children in the United States. While  histological evidence of myocarditis can be found in all patients with acute KD, only a minority of patients are clinically symptomatic and a subset demonstrate echocardiographic evidence of impaired myocardial function, as well as increased left ventricular mass, presumed to be due to myocardial edema and inflammation. Up to a third of KD patients fail to respond to first-line therapy with intravenous immunoglobulin (IVIG), and the use of interleukin (IL)-1 receptor antagonist (IL-1Ra, anakinra) is currently being investigated as an alternative therapeutic approach to treat IVIG-resistant patients. In this study, we sought to investigate the effect of IL-1Ra on myocardial dysfunction and its relation to myocarditis development during KD vasculitis. We used the Lactobacillus casei cell-wall extract (LCWE)-induced murine model of KD vasculitis and investigated the effect of IL-1Ra pretreatment on myocardial dysfunction during KD vasculitis by performing histological, magnetic resonance imaging (MRI) and echocardiographic evaluations. IL-1Ra pretreatment significantly reduced KD-induced myocardial inflammation and N-terminal pro B-type natriuretic peptide (NT-proBNP) release. Both MRI and echocardiographic studies on LCWE-injected KD mice demonstrated that IL-1Ra pretreatment results in an improved ejection fraction and a normalized left ventricular function. These findings further support the potential beneficial effects of IL-1Ra therapy in preventing the cardiovascular complications in acute KD patients, including the myocarditis and myocardial dysfunction associated with acute KD.

Myocardial fibrosis after adrenergic stimulation as a long-term sequela in a mouse model of Kawasaki disease vasculitis

Kawasaki disease (KD), the leading cause of acquired cardiac disease among children, is often associated with myocarditis that may lead to long-term myocardial dysfunction and fibrosis. Although those myocardial changes develop during the acute phase, they may persist for decades and closely correlate with long-term myocardial sequelae. Using the Lactobacillus casei cell wall extract-induced (LCWE-induced) KD vasculitis murine model, we investigated long-term cardiovascular sequelae, such as myocardial dysfunction, fibrosis, and coronary microvascular lesions following adrenergic stimuli after established KD vasculitis. We found that adrenergic stimulation with isoproterenol following LCWE-induced KD vasculitis in mice was associated with increased risk of cardiac hypertrophy and myocardial fibrosis, diminished ejection fraction, and increased serum levels of brain natriuretic peptide. Myocardial fibrosis resulting from pharmacologic-induced exercise after KD development was IL-1 signaling dependent and was associated with a significant reduction in myocardial capillary CD31 expression, indicative of a rarefied myocardial capillary bed. These observations suggest that adrenergic stimulation after KD vasculitis may lead to cardiac hypertrophy and bridging fibrosis in the myocardium in the LCWE-induced KD vasculitis mouse model and that this process involves IL-1 signaling and diminished microvascular circulation in the myocardium.

Analysis of Exercise Capacity of Children with Kawasaki Disease by a Coronary Artery z Score Model (ZSP Version 4) Derived by the Lambda-Mu-Sigma Method

OBJECTIVE

To compare exercise capacity measured by direct cardiopulmonary exercise testing (CPET) of children with Kawasaki disease with different coronary artery diameter z scores (CA z score).

STUDY DESIGN

This was a retrospective study that recruited children with Kawasaki disease after the acute stage receiving CPETs determined by CPET with treadmill. CA z score was based on a model using the Lambda-Mu-Sigma method. Max-Z was defined as the maximum z score of the proximal left anterior descending CA (LCA) or right CA (RCA). Children with Kawasaki disease with a Max z <2.0 and ≥2.0 were defined as Kawasaki disease group 1 and Kawasaki disease group 2, respectively.

RESULTS

We recruited 32 boys and 17 girls with a mean age of 12.39 ± 3.61 years. Kawasaki disease group 1 (n = 36) had significantly higher peak metabolic equivalent (peak-MET) and peak rate pressure product (PRPP) than Kawasaki disease group 2 (n-13) (P = .046, P < .001). Max-Z correlated with peak-MET moderately and negatively (P < .001, Spearman rho= - .506). Max-Z correlated with PRPP modestly and negatively (P = .011, Spearman rho= - .360).

CONCLUSIONS

Children after Kawasaki disease with a coronary artery Max-Z ≥ 2.0 had significantly lower peak exercise capacity than those with a Max-Z < 2.0. Max-Z might be used as an indicator of CA reserve and exercise capacity during peak exercise after the acute stage of Kawasaki disease.

Serial evaluation of myocardial function using the myocardial performance index in Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is known as systemic vasculitis, and more than half of the patients with KD have myocarditis, which can induce ventricular dysfunction. In this study, we evaluate left ventricular (LV) dysfunction in patients with KD based on the myocardial performance index (MPI) using pulse Doppler (PD) and tissue Doppler imaging (TDI), from the acute to convalescent phases.

METHODS

We retrospectively studied 89 children diagnosed with KD from January 2010 to August 2012. We assessed the presence of coronary artery lesions (CALs) and the LV ejection fraction, PD-MPI, and TDI-MPI at diagnosis, and 2, 14, and 56 days after intravenous immunoglobulin (IVIG) treatment. We enrolled 70 healthy children as a control group.

RESULTS

The ejection fraction in patients with KD at diagnosis (67.3 ± 0.9%) was lower than that in the control group (69.8 ± 0.8%, P = 0.035), and the LV TDI-MPIs for patients with KD at diagnosis (0.49 ± 0.01) and 2 days after IVIG treatment (0.48 ± 0.01) were higher than those in the control group (0.45 ± 0.01, P = 0.002, P = 0.033, respectively). No significant differences were found in the LV dysfunction between the patients with complete and incomplete KD. Septal TDI-MPIs in patients with KD with CAL at diagnosis (0.52 ± 0.02) were higher than those in patients with KD without CAL (0.47 ± 0.01, P = 0.019).

CONCLUSIONS

Transient LV dysfunction occurred in patients with complete and incomplete KD in the acute stage. In patients with KD with CAL at diagnosis, the LV dysfunction was more prominent. The PD-MPI and TDI-MPI are useful parameters for assessing LV function in patients with KD.

Recovery of myocardial mechanics in Kawasaki disease demonstrated by speckle tracking and tissue Doppler methods

AIM

To investigate myocardial deformation and function during treatment for Kawasaki disease (KD) in children.

METHODS

We performed speckle tracking echocardiography (STE) and tissue Doppler imaging (TDI) in 15 children with KD and 15 healthy children during treatment for KD. STE was performed for longitudinal and circumferential strain (S) and strain rate (SR) at the left ventricle (LV) and for longitudinal S and SR at the right ventricle (RV). TDI was performed at the base of interventricular septum (IVS), LV, and RV.

RESULTS

Among TDI parameters, E_m and ejection time (ET) at IVS, ET at LV and ET at RV obtained obtained before treatment were significantly lower in patients with KD compared to controls. After treatment, in spite of improvements, ET at IVS and ET at RV remained significantly lower in patients with KD compared to controls. Left ventricular global longitudinal and circumferential S and SR values obtained before treatment were significantly lower in patients with KD compared to controls. Left ventricular S and SR values were found to be increased after treatment. However, left ventricular global circumferential S value remained significantly lower in patients with KD compared to controls. There were no significant differences in right ventricular global longitudinal S and SR values between patients and controls before treatment.

CONCLUSION

During acute phase, patients with KD have reduced global left ventricular S and SR which may be more sensitive indicators of myocardial inflammation. This study showed gradual improvements in left ventricular myocardial function during treatment for KD.

Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association

BACKGROUND

Kawasaki disease is an acute vasculitis of childhood that leads to coronary artery aneurysms in ≈25% of untreated cases. It has been reported worldwide and is the leading cause of acquired heart disease in children in developed countries.

METHODS AND RESULTS

To revise the previous American Heart Association guidelines, a multidisciplinary writing group of experts was convened to review and appraise available evidence and practice-based opinion, as well as to provide updated recommendations for diagnosis, treatment of the acute illness, and long-term management. Although the cause remains unknown, discussion sections highlight new insights into the epidemiology, genetics, pathogenesis, pathology, natural history, and long-term outcomes. Prompt diagnosis is essential, and an updated algorithm defines supplemental information to be used to assist the diagnosis when classic clinical criteria are incomplete. Although intravenous immune globulin is the mainstay of initial treatment, the role for additional primary therapy in selected patients is discussed. Approximately 10% to 20% of patients do not respond to initial intravenous immune globulin, and recommendations for additional therapies are provided. Careful initial management of evolving coronary artery abnormalities is essential, necessitating an increased frequency of assessments and escalation of thromboprophylaxis. Risk stratification for long-term management is based primarily on maximal coronary artery luminal dimensions, normalized as Z scores, and is calibrated to both past and current involvement. Patients with aneurysms require life-long and uninterrupted cardiology follow-up.

CONCLUSIONS

These recommendations provide updated and best evidence-based guidance to healthcare providers who diagnose and manage Kawasaki disease, but clinical decision making should be individualized to specific patient circumstances.

Atrioventricular depolarization differences identify coronary artery anomalies in Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is the leading cause of acquired heart disease in children. Signal average electrocardiogram changes in patients during the acute phase of KD with coronary artery anomalies (CAA) include depolarization changes. We set out to determine if 12-lead-derived atrioventricular depolarization differences can identify CAA in patients with KD.

METHODS

A blinded, retrospective case-control study of patients with KD was performed. Deep Q waves, corrected QT-intervals (QTc), spatial QRS-T angles, T-wave vector magnitudes (RMS-T), and a novel parameter for assessment of atrioventricular depolarization difference (the spatial PR angle) and a two dimensional PR angle were assessed. Comparisons between groups were performed to test for significant differences.

RESULTS

One hundred one patients with KD were evaluated, with 68 having CAA (67.3%, mean age 3.6 ± 3.0 years, 82.6% male), and 32 without CAA (31.7%, mean age 2.7 ± 3.2 years, 70.4% male). The spatial PR angle significantly discriminated KD patients with CAA from those without, 59.7° ± 31.1° versus 41.6° ± 11.5° (p < .001). A spatial PR angle cutoff value of 56.9° gave positive/negative predictive values and odds ratios of 93.8%, 43.5%, and 11.5% (95% confidence interval (CI) 2.6-52.2). The two dimensional PR angle either below 7° or above 92° gave positive/negative predictive values and odds ratios of 100.0%, 38.8%, and 21.1% (95% CI 1.2-362.8). No other parameters significantly differentiated the groups.

CONCLUSION

Atrioventricular depolarization differences, measured by the spatial or two dimensional PR angle differentiate KD patients with CAA versus those without.

Repolarization Vector Magnitude Differentiates Kawasaki Disease from Normal Children

INTRODUCTION

Kawasaki disease (KD) is the leading cause of acquired heart disease in children. The 12-lead electrocardiogram (ECG) changes in patients during the acute phase of KD include flattened T waves and prolonged corrected QT intervals (QTc). We set out to determine the 12-lead ECG and vectorcardiography predictors for identification of patients with KD and which of these predictors would be clinically useful for early identification of those with coronary artery anomalies (CAA).

METHODS

A blinded, retrospective case-control study of patients with KD and age-matched controls was performed. Deep Q waves, QTc, spatial QRS-T angles, and T-wave vector magnitude (root mean square of the T wave, RMS-T) were assessed. Comparisons between groups were performed to test for significant differences.

RESULTS

Fifty patients with KD (mean age 3.1 ± 3.1 years, 26% female) were compared to 50 previously healthy control patients (mean age 3.8 ± 2.9 years, 44% female). Of the KD patients, 32 (64%) were diagnosed as incomplete KD and 28 (56%) of them had CAA. When compared to the control group, KD patients had abnormal Q waves (72% vs 44% P = 0.005), shorter QTc values (395.1 ± 24.7 ms vs 410.4 ± 34.7 ms, P = 0.013), and lower RMS-T (0.42 ± 0.02 mV vs 0.63 ± 0.03 mV P < 0.001), respectively. Incomplete KD was also discriminated from controls by the same parameters. No differences were noted between KD patients with versus without CAA.

CONCLUSION

The RMS-T differentiates complete and incomplete KD from controls. KD patients with CAA were not differentiated from those without CAA.

Myocardial Strain and Strain Rate in Kawasaki Disease: Range, Recovery, and Relationship to Systemic Inflammation/Coronary Artery Dilation

BACKGROUND

Kawasaki Disease (KD), a systemic vasculitis of medium sized vessels, is the most common cause of acquired heart disease among children in the developed world. Some KD patients demonstrate echocardiographic evidence of depressed myocardial mechanics. However, the incidence, etiology, and reversibility of abnormal mechanics in KD patients remain undefined.

METHODS AND RESULTS

We retrospectively studied 41 KD patients and measured myocardial strain and strain rate by velocity vector imaging from pre-treatment and convalescent echocardiograms. Pre-treatment procalcitonin, C-reactive protein (CRP), and coronary artery z-scores were obtained in all patients and compared between the groups with preserved versus depressed acute phase mechanics. The change in mechanics between the acute and convalescent phases was also assessed. Patients with initially low longitudinal strain improved by the convalescent period (mean difference - 4.0%; p<0.005) with the greatest improvement occurring in patients with the lowest initial strain (-7.3%; p<0.05). Patients with higher initial strain did not change significantly by the convalescent period. Patients with lower longitudinal and circumferential strain demonstrated higher median procalcitonin levels (1.2 vs. 0.3 ng/mL; p<0.05 and 1.8 vs. 0.4 ng/mL; p<0.05 respectively) and a trend towards higher CRP, but no difference in coronary artery z-scores. Strain rate was not associated with inflammatory markers or coronary artery z-scores.

CONCLUSIONS

The range of strain found in our cohort was large. Improvement in mean strain was driven primarily by patients with lower initial strain. Lower strain was associated with increased markers of systemic inflammation, but not proximal coronary artery changes.

Cardiopulmonary Function, Exercise Capacity, and Echocardiography Finding of Pediatric Patients With Kawasaki Disease: An Observational Study

Coronary artery (CA) abnormalities influence exercise capacity (EC) of patients with Kawasaki disease (KD), and Z-score of CA is a well established method for detecting CA aneurysm. We studied the influence of KD on cardiopulmonary function and EC; meanwhile we analyzed echocardiographic findings of KD patients. We also assessed the correlation between CA Z-score and EC of KD patients to see if CA Z-score of KD patients could reflect EC during exercise.Sixty-three KD patients were recruited as KD group 1 from children (aged 5-18 y) who received transthoracic echocardiographic examinations and symptom-limited treadmill exercise test for regular follow-up of KD from January 2010 to October 2014 in 1 medical center. We then divided KD group 1 into KD group 2 (<5 y, n = 12) and KD group 3 (≥5 y, n = 51) according to time interval between KD onset to when patients received test. Control groups were matched by age, sex, and body mass index. Max-Z of CA was defined as the maximal Z-score of the proximal LCA or RCA by Dalliarre equation or Fuse calculator.All routine parameters measured during standard exercise test were similar between KD and control groups, except that peak rate pressure products (PRPPs) in KD group 1 to 3 were all lower than corresponding control groups significantly (P = 0.010, 0.020, and 0.049, respectively). PRPPs correlated with Max-Z of CA by both equations modest inversely (by Dallaire, P = 0.017, Spearman rho = -0.301; by Fuse, P = 0.014, Spearman rho = -0.309).Our study recruited larger number of KD patients and provided a newer data of EC of KD patients. Our finding suggests that after acute stage of KD, patients could maintain normal cardiorespiratory fitness. Therefore, we believe that it is important to promote cardiovascular health to KD patients and KD patients should exercise as normal peers. However, since KD patients might still have compromised coronary perfusion during exercise, it remains crucial to assess and monitor cardiovascular risk of KD patients. Max-Z of CA correlates with PRPP modest inversely and might be used as a follow-up indicator of CA reserve during exercise after acute stage of KD.

Noncoronary inflammation in Kawasaki disease is associated with abnormal myocardial deformation in the acute phase

BACKGROUND

Patients with Kawasaki disease (KD) are at risk for developing coronary artery lesions, but the association of noncoronary changes such as mitral regurgitation (MR) and/or pericardial effusion (PE) with cardiac mechanics in the acute phase of KD has not been previously described. The aim of this study was to test the hypothesis that these noncoronary markers for carditis are associated with abnormalities in strain (ε) and strain rate (SR) in patients with MR or PE not appreciated by conventional echocardiography.

METHODS

Longitudinal and circumferential ε and SR analyses were retrospectively performed on patients with KD. Patients with and without MR or PE were compared. Strain values were also compared between patients with and without coronary artery lesions. Values for ejection fraction, shortening fraction, and clinical laboratory parameters were correlated with MR or PE. Follow-up echocardiographic outcomes were recorded at the first encounter after initial diagnosis. Follow-up ε and SR data were also obtained in the group with MR or PE and altered ventricular mechanics at diagnosis.

RESULTS

Of the 110 patients reviewed, 92 had appropriate image quality for either longitudinal ε and SR or circumferential ε and SR analysis. Twenty-eight patients (30%) had either MR or PE. Longitudinal ε and SR were significantly decreased in patients with MR or PE compared with patients without MR or PE (ε: -16.4 ± 4.0% vs -19.0 ± 3.7%, P = .004; SR: -1.3 ± 0.7 vs -1.6 ± 0.4 sec(-1), P = .03). No significant difference in longitudinal ε or SR was noted between patients with and without coronary artery lesions (ε: -17.9 ± 4.1% vs -17.8 ± 3.8%, P = .50; SR: -1.5 ± 0.3 vs -1.6 ± 0.8 sec(-1), P = .50). In the group with abnormal coronary arteries, presence of MR or PE was correlated with decreased longitudinal ε (-16.1 ± 3.6% vs -18.9 ± 3.4%, P = .02), without a significant difference in longitudinal SR (-1.6 ± 0.4 vs -1.5 ± 0.4 sec(-1), P = .20). At approximately 3-week follow-up (21.3 ± 15.8 days), longitudinal ε and SR for the group with MR or PE had increased significantly compared with diagnosis (ε: -16.4 ± 4.3% vs -18.6 ± 0.5%, P = .03; SR: -1.3 ± 0.6 vs -1.8 ± 0.4 sec(-1), P = .008), coincident with resolution of MR or PE. In both groups, erythrocyte sedimentation rate and C-reactive protein were elevated (85.3 ± 36.2 mm/h vs 75.1 ± 33.1 mm/h [P = .34] and 12.3 ± 6.7 vs 11.7 ± 8.2 mg/dL [P = .83]), but only modest correlations were noted between longitudinal ε and elevated erythrocyte sedimentation rate (r = 0.52, P = .01; confidence interval, 0.10-0.80) and C-reactive protein (r = 0.50, P = .02; confidence interval, 0.10-0.80) in patients with MR or PE. Shortening fraction and ejection fraction were within the normal range in both groups.

CONCLUSIONS

Patients presenting with KD with MR or PE at diagnosis are likely to have altered ventricular mechanics compared with patients with KD without MR or PE despite normal conventional echocardiographic measures of function. There is no significant difference in ventricular mechanics when comparing patients with KD with coronary ectasia or aneurysms and those without coronary lesions. Presence of abnormal ε in patients with KD with altered ventricular mechanics correlates modestly with laboratory inflammatory markers. Peak systolic longitudinal ε and SR increased significantly at 3-week follow-up compared with initial diagnosis, coincident with resolution of MR or PE.

Sudden cardiac death in the young: the bogeyman

Sudden cardiac death in the young is a relatively uncommon but marked event usually related to congenital diseases or anomalies. Despite the prevalence of each condition being variable, most common causes include primary myocardial diseases and arrhythmic disorder, frequently with inheritance pattern. Sudden cardiac death is usually preceded by symptoms, thus making personal and family history fundamental for its prevention. Nevertheless, in more than 50% of cases, sudden cardiac death is the first manifestation of the disease. In this review, we describe the different causes of sudden cardiac death, their incidence, and currently used preventive strategies.

Evaluation of left ventricular systolic strain in children with Kawasaki disease

The current study aimed to assess left ventricular (LV) longitudinal systolic strains in children with KD using two-dimensional speckle-tracking imaging and to analyze the relationship of LV myocardial deformation to coronary lesions and laboratory markers. The study enrolled 101 children with acute KD. An additional 50 age- and gender-matched normal children were enrolled as control subjects. During different phases of KD, echocardiograms were recorded for 61 children. Two-dimensional strain analysis software was used to track myocardial movement and obtain the strain from each LV segment. The LV longitudinal systolic strain decreased significantly in children with acute KD but increased immediately after intravenous immunoglobulin therapy. At 6-8 weeks after the onset of KD, all LV strains had recovered to normal. The LV systolic strain was not associated with coronary dilation in either acute or convalescent KD. In acute KD, aspartate transaminase, alanine transaminase, erythrocyte sedimentation rate, C-reactive protein (CRP), and hemoglobin (Hb) were found to be associated with coronary dilation, whereas LV systolic strains were found to be correlated with elevated CRP and decreased Hb. Speckle-tracking imaging of LV systolic strain was simple and accurate in evaluating LV function during different phases of KD. No association between LV dysfunction and coronary dilation was observed, but a relationship with CRP and Hb was found. Further studies are recommended to validate the current study results and explore further how these findings can improve clinical practice.

Aortic stiffness studies in children with Kawasaki disease: preliminary results from a follow-up study from North India

Kawasaki disease (KD) is an acute medium vessel vasculitis seen in children. Coronary artery abnormalities are the most notable long-term complications. Intravenous immunoglobulin therapy has led to significant reduction in incidence of coronary aneurysms. However, higher risk of cardiovascular disease has been noted even in those children who have never been reported to develop coronary artery aneurysms during the subacute phase. Noninvasive estimation of this cardiovascular risk is useful in initiating timely preventive strategies. Arterial stiffness has been shown to be an independent predictor of cardiovascular events in general population. This study was aimed at measuring abdominal aorta stiffness in a cohort of children with KD from North India. Thirty children diagnosed to have KD at least 5 years prior to enrollment were evaluated by echocardiography for cardiac and abdominal aorta studies. Electrocardiographs were done in all patients for QT dispersion. There was a noticeable trend toward lower aortic strain, higher pressure strain elastic modulus and normalized pressure strain elastic modulus in children in the study group, though this difference did not reach statistical significance. Mean corrected QT dispersion was significantly higher in cases compared with controls. On cardiac evaluation, none of the subjects had any residual coronary artery involvement. A trend toward lower distensibility and higher stiffness of abdominal aorta was seen in cases compared with controls, though it was not found to be statistically significant. This could be a predictor of premature atherosclerosis in long term. Significantly higher QT dispersion was seen in cases compared with controls. More multicentric studies with larger sample size and longer follow-up periods are needed to clarify this issue.

Peribronchovascular haze: a frequently observed finding on chest X-rays in the acute phase of Kawasaki disease

PURPOSE

To evaluate the frequency of peribronchovascular haze on chest X-rays (CXR) in patients with Kawasaki disease (KD), a finding not previously emphasized, and to contrast this finding with clinical, laboratory and echocardiographic findings.

METHODS

Sixty-nine patients diagnosed as KD from January 2010 to December 2011 were eligible for this study. The initial CXRs were retrospectively reviewed by two radiologists for the presence of peribronchovascular haze and related findings. Echocardiography was reviewed by one pediatrician for the presence of coronary artery abnormalities. The follow up CXRs and post-remission echocardiograms were also reviewed. Patients' medical records were reviewed for clinical findings. Correlation between CXR findings and clinical findings were assessed.

RESULTS

On the initial CXR, peribronchovascular haze was observed in 57/69 patients (82.6 %). Twenty-nine out of 69 patients showed abnormalities on echocardiogram (42.0 %). In the follow-up studies, CXR findings were improved in 25/29 patients (86.2 %). The frequencies of five principal clinical features of KD were from 55.1 to 88.4 %. There was no statistically significant correlation between the CXR finding and clinical findings.

CONCLUSION

Peribronchovascular haze on CXR was observed in the acute phase of KD as frequently as the principal clinical features of KD, and more frequently than echocardiographic abnormalities.

An update on Kawasaki disease II: clinical features, diagnosis, treatment and outcomes

This is the second of two updates on Kawasaki disease. The first review focused on epidemiology and aetio-pathogenesis. Here, we review the clinical features and diagnosis of Kawasaki disease, as well as recent evidence on treatment, follow-up and cardiovascular outcomes.

The clinical profile of Kawasaki disease of children from three Polish centers: a retrospective study

Kawasaki disease (KD) is one of the most common vasculitides of childhood. The aim of this retrospective study is to determine the incidence of KD and to evaluate its presenting symptoms, clinical course, laboratory tests, and treatment in patients with complete KD and incomplete KD at three pediatric rheumatology centers in Poland from January 2011 to December 2012. A total of 27 Caucasian children (12 boys and 15 girls) with median age of 3 years (range 4 months–12 years) were included in this study. The incidence of complete versus incomplete KD was 17 (63 %) versus 10 (37 %) children, respectively. Patients with incomplete KD significantly less presented cervical lymphadenopathy (20 vs. 88.2 %; p = 0.00075), changes in extremities (30 vs. 76.5 %; p = 0.04), and bilateral nonpurulent conjunctivitis (60 vs. 100 %; p = 0.01). Cardiac assessments show that the majority of patients with KD have not got coronary artery aneurysms (CAA). The median time from the onset of symptoms to intravenous immunoglobulin (IVIG) infusion was 7 days for complete KD and 11 days for incomplete KD. IVIG delay in the incomplete KD had no effect on the incidence of CAA. In conclusion, there were no differences in demographic features, age of onset, and laboratory tests of patients with complete and incomplete KD. Patients with incomplete KD significantly rarely presented cervical lymphadenopathy, changes in extremities, and conjunctival injection. Electrocardiography is a sensitive test to recognize cardiac involvement in the acute phase of KD. Despite the fact that incomplete forms of presentation often delay diagnosis, in most patients treatment with IVIG can avoid complication of CAA.

Long-term management of Kawasaki disease: implications for the adult patient

Coronary artery complications from Kawasaki disease (KD) range from no involvement to giant coronary artery aneurysms (CAA). Current long-term management protocols are calibrated to the degree of maximal and current coronary artery involvement reflecting the known likelihood of severe long-term cardiac complications. It has recently been suggested that all KD patients may be at potential risk of severe long-term cardiac complications. If this assertion was to be confirmed, current follow-up protocols would need to be extensively modified, with important implications both for the growing adult population with a previous history of KD and for the healthcare system. Based on the available evidence, patients with multiple large and/or giant CAA are at substantial risk of severe long-term cardiac complications and should have regular specialized follow-up. Patients with transient or no CAA have not been reported to be at risk of severe long-term cardiac complications. The influence of KD on the atherosclerotic process remains suboptimally defined, and should be the focus of future studies. Heightened cardiovascular risk factor surveillance and management is recommended regardless of coronary artery involvement. Based on the currently available evidence, existing long-term management protocols seem to be appropriately calibrated to the level of risk. Revised long-term management protocols should incorporate newer, noninvasive imaging methods and intensive management of atherosclerotic risk. There is insufficient evidence at this time to mandate long-term specialized follow-up and invasive testing for patients who have not had CAA.

Kawasaki syndrome: an intriguing disease with numerous unsolved dilemmas

More than 40 years have passed since Kawasaki syndrome (KS) was first described. Yet KS still remains an enigmatic illness which damages the coronary arteries in a quarter of untreated patients and is the most common cause of childhood-acquired heart disease in developed countries. Many gaps exist in our knowledge of the etiology and pathogenesis of KS, making improvements in therapy difficult. In addition, many KS features and issues still demand further efforts to achieve a much better understanding of the disease. Some of these problem areas include coronary artery injuries in children not fulfilling the classic diagnostic criteria, genetic predisposition to KS, unpredictable ineffectiveness of current therapy in some cases, vascular dysfunction in patients not showing echocardiographic evidence of coronary artery abnormalities in the acute phase of KS, and risk of potential premature atherosclerosis. Also, the lack of specific laboratory tests for early identification of the atypical and incomplete cases, especially in infants, is one of the main obstacles to beginning treatment early and thereby decreasing the incidence of cardiovascular involvement. Transthoracic echocardiography remains the gold-standard for evaluation of coronary arteries in the acute phase and follow-up. In KS patients with severe vascular complications, more costly and potentially invasive investigations such as coronary CT angiography and MRI may be necessary. As children with KS with or without heart involvement become adolescents and adults, the recognition and treatment of the potential long term sequelae become crucial, requiring that rheumatologists, infectious disease specialists, and cardiologists cooperate to develop specific guidelines for a proper evaluation and management of these patients. More education is needed for physicians and other professionals about how to recognize the long-term impact of systemic problems related to KS.

Cardiovascular biomarkers in acute Kawasaki disease

BACKGROUND

Endomycocardial biopsies have demonstrated that subclinical myocarditis is a universal feature of acute Kawasaki disease (KD).

METHODS

We investigated biochemical evidence of myocardial strain, oxidative stress, and cardiomyocyte injury in 55 acute KD subjects (30 with paired convalescent samples), 54 febrile control (FC), and 50 healthy control (HC) children by measuring concentrations of cardiovascular biomarkers.

RESULTS

Levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and soluble ST2 (sST2) were elevated in acute vs. convalescent KD, FC, and HC (p≤0.002), while γ-glutamyl transferase and alanine amino transferase as measures of oxidative stress were increased in acute vs. FC (p≤0.0002). Cardiac troponin I (cTnI) levels, using a highly sensitive assay, were elevated in 30% and 40% of paired acute and convalescent KD subjects, respectively, and normalized within two years of disease onset. NT-proBNP and sST2 negatively correlated with deceleration time, but only NT-proBNP correlated with MV E:A ratio and internal diameter of the coronary arteries (RCA/LAD Zworst).

CONCLUSIONS

NT-proBNP and sST2 were elevated in acute KD subjects and correlated with impaired myocardial relaxation. These findings, combined with elevated levels of cTnI, suggest that both cardiomyocyte stress and cell death are associated with myocardial inflammation in acute KD.

The Relationship between Coronary Artery Aneurysm and QT Interval Dispersion in Acute Phase of Kawasaki Disease

OBJECTIVE

QT dispersion (QTd) has been proposed as a marker of ventricular repolarization inhomogeneity and several investigations have proved the relationship between it and cardiac ischemia, ventricular arrhythmia and sudden cardiac death. The aim of this study was to assess the relation between coronary artery involvement and QTd, and QTc dispersion (QTcd) in the acute phase of Kawasaki disease (KD).

METHODS

We studied 65 patients with acute KD. Patients were divided into 3 groups. Group one consisted of 48 patients without coronary artery involvement. Group two comprised 13 patients with small to medium size aneurysm. In Group three there were 4 patients with giant aneurysm or multiple small to medium size aneurysms or thrombosis in coronary arteries. For each patient 12 lead electrocardiography was obtained, and QT, QTc, QTd, QTcd, and RR interval were calculated.

FINDINGS

There were 40 males and 25 females with a mean age of 41.4±31.1 months. There was no significant difference in QT, QTc, RR measurements between 3 groups. QTd was greater in group 3 versus group 1 and 2, but the difference was not statistically significant (P=0.06). QTcd was significantly greater in group 3 than in groups 1 and 2 (75.02±11.53 ms versus 46.82±15.39 ms and 48.88±10. 55 ms respectively (P = 0.04). The sensitivity of QTcd ≥60 ms to detect the patients with severe coronary arteries involvement was 100%, the specificity was 93.4%, positive predictive value was 50%, negative predictive value was 100%, and accuracy was 93.8%.

CONCLUSION

QTcd can be used as a predictive factor for diagnosis of severe coronary arteries involvement in the acute phase of KD.

Evaluation of myocardial function using the Tei index in patients with Kawasaki disease

Myocarditis is a well-recognized component of Kawasaki disease, with left ventricular dysfunction occurring in more than half of the patients during the acute phase of the disease. The purpose of our study was to evaluate myocardial function in these patients using the myocardial performance index, also known as the Tei index. In a prospective study, 14 patients underwent echocardiographic evaluation, first at the time of diagnosis of the disease, in its acute phase before treatment with intravenous immunoglobulin and then 2 weeks later after treatment with immunoglobulin. We assessed the Tei-index, the ejection fraction, shortening fraction, and the presence of valvar regurgitation, pericardial effusion, or coronary arterial involvement. As a control, we also assessed 22 healthy children, matched for age and sex with the study population. Of the patients, half had an increased left ventricular Tei-index in the acute phase, as compared with the data obtained after treatment, the index changing from 0.43 +/- 0.08 to 0.35 +/- 0.06 (p equal to 0.003). An increased index for the right ventricle was found in 5 patients (36%), values being 0.30 +/- 0.05 as opposed to 0.26 +/- 0.04 (p equal to 0.009). Of the patients, 5 (35.7%) also had decreased ejection fractions and proportional shortening fractions during the acute phase, confirming left ventricular dysfunction. We concluded that the Tei-index, which measures combined systolic and diastolic function, is a simple, sensitive, and accurate tool for estimating global myocardial dysfunction in patients with Kawasaki disease.

QT interval dispersion in North Indian children with Kawasaki disease without overt coronary artery abnormalities

Increased QT interval dispersion has been associated with an increased risk for ventricular arrhythmias and sudden cardiac events. We examined the QT interval dispersion in 20 North Indian children with Kawasaki disease (KD) with no coronary artery abnormalities on echocardiography compared the same with matched controls. The study population consisted of 20 children in convalescent phase of KD and 20 age and sex-matched healthy controls. Intervals were measured with the use of a digital caliper with least count of 0.01 mm by a single blinded observer. The QTc dispersion was calculated as the difference between the maximum and minimum corrected QT intervals in 12 and 8 leads (i.e. the 6 precordial leads, the shortest extremity lead, and the median of the 5 other extremity leads). Of the 480 leads obtained (12 per subject), 36 were excluded from analysis (15 because of poor T wave formation and 11 because of presence of U waves). Children with KD had significantly higher QTc dispersion in 12 lead (67.08 ± 17.72 ms compared to 47.63 ± 16.48 ms in controls P ≤ 0.001) as well as 8 lead (60.51 ± 18.54 ms compared to 42.92 ± 18.03 ms in controls P ≤ 0.001) analysis. There was no correlation between delay in IVIG therapy and QT interval dispersion. In conclusion, QT interval dispersion is significantly increased in North Indian children with KD. The dispersion is indicative of inhomogenous ventricular repolarization and may represent increased risk for developing ventricular arrhythmia in this population.