Myocardial Perfusion Reserve Index in Children With Kawasaki Disease

Assessment of Coronary Microvascular Dysfunction in Patients with Systemic Vasculitis

INTRODUCTION

Coronary microvascular dysfunction (CMD) is characterized by impaired coronary blood flow in the absence of obstructive coronary artery disease. CMD primarily involves the microvasculature, leading to myocardial ischemia, angina, and increased cardiovascular risk. Systemic vasculitides (e.g., giant cell arteritis, antineutrophil cytoplasmic antibody-associated vasculitis, and Takayasu arteritis) are a group of autoimmune conditions known to affect the vasculature through inflammation of the blood vessels that have been associated with more prevalent and severe CMD. Although systemic inflammation likely plays a role in the increased risk of cardiovascular events, the underlying pathogenesis is not well understood.

PURPOSE OF REVIEW

Invasive and non-invasive techniques for assessing coronary microvascular function have been developed to assess for blood flow and coronary flow reserve (CFR), defined as the ratio of the maximum achievable blood flow during stress to the resting blood flow. The purpose of this review is to further explore the relationship between vasculitis and CMD as well as the techniques available for assessing this association.

RECENT FINDINGS

Studies have shown that CMD is significantly more prevalent in patients with systemic vasculitis compared to the general population. Moreover, in the absence of significant atherosclerotic burden, patients with vasculitis have a lower CFR than controls, indicating more severely impaired coronary vasomotor function. This suggests that systemic inflammation itself is a factor in driving coronary vasomotor abnormalities and CMD development. CMD contributes to cardiovascular morbidity in patients with systemic vasculitis, underscoring the need for early recognition and management. Further studies are needed to determine whether therapies targeting the reduction of systemic inflammation can lead to improved coronary microvascular function and cardiovascular outcomes.

Infant Kawasaki disease complicated with supraventricular tachycardia: a case report and literature review

BACKGROUND

The occurrence of arrhythmias as a complication of Kawasaki disease (KD) is extremely rare. Moreover, previous literature showed a low incidence of arrhythmias during the acute phase of KD, and the majority occurred in the subacute and chronic phases. To date, we have found only 17 sporadically reported global cases in the available literature.

CASE PRESENTATION

We present the first documented case of an infant with KD complicated with supraventricular tachycardia (Atrioventricular reentrant tachycardia) during the acute phase. The arrhythmia resolved promptly after the combination therapy of intravenous Immunoglobulin (IVIG) and steroids during the acute phase since the inflammation subsided. Additionally, we conducted a review and summary of cases involving KD-related arrhythmias.

CONCLUSIONS

KD rarely causes arrhythmias, which might be associated with myocarditis and myocardial ischemia attributed to scar formation and/or excessive inflammatory factors damaging the conduction system. Strengthening the early identification and management of complications in patients with KD and personalized follow-up strategies for high-risk children during the chronic phase can enhance patients' prognosis.

Establishment of a canine model of pulmonary arterial hypertension induced by dehydromonocrotaline and ultrasonographic study of right ventricular remodeling

OBJECTIVE

Pulmonary arterial hypertension (PAH) means high blood pressure in the lungs. We aimed to observe the right ventricular size, wall thickness and characteristic functional changes and their associations with PAH in an established model of beagle dogs, and to explore convenient, reliable and sensitive ultrasound indicators for assessing right ventricular remodeling.

METHODS

Twenty healthy beagle dogs (8-10 kg) were randomly divided into control group (N-dimethylformamide, n = 10) and dehydromonocrotaline (DHMCT) group (DHMCT, n = 10). N-dimethylformamide or DHMCT was injected through a catheter into the right atrium, and then right heart catheterization, routine echocardiography and two-dimensional speckle tracking imaging (2D-STI) were performed before modeling (0 weeks) and 8, 14 weeks after modeling. Hemodynamic parameters and right ventricular function-related ultrasound data were acquired. At the end of the experiment, the animals were killed and the lung tissues were taken for HE staining. Left and right ventricular walls were separated and weighed respectively, and right ventricular hypertrophy index (RVHI) was measured. The associations of the routine ultrasound data and 2D-STI data at each time point with hemodynamic parameters and RVHI were analyzed.

RESULTS

At 0, 8 and 14 weeks, gradual decreases in the right ventricular global longitudinal strain (RVLS) were found in DHMCT group. RVH occurred in DHMCT group, and DHMCT group had a significantly higher RVHI than that of control group (49.83 ± 4.83% vs. 39.80 ± 1.40%, P < .001) and larger pulmonary artery media thickness. RVLS had significant positive correlations with RVSP (r = 0.74, P < .001), mRVP (r = 0.72, P < .001), PASP (r = 0.75, P < .001), mPAP (r = 0.72, P < .001) and PVR (r = 0.68, P < .001). There was a significant positive correlation between RVLS and RVHI (r = 0.74, P < .001).

CONCLUSION

The right ventricular function in PAH can be effectively assessed by echocardiography, and RVLS measured by 2D-STI sensitively reflects right ventricular remodeling following PAH.

Evaluation of comprehensive myocardial contractility in children with Kawasaki disease by cardiac magnetic resonance in a large single center

BACKGROUND

Children with Kawasaki disease (KD) and coronary artery lesions (CALs) can develop myocardial ischemia, fibrosis, and abnormal contractility. We aimed to assess the association between myocardial mechanical deformation with myocardial fibrosis, ischemia, and CALs.

METHODS

In total, 76 KD and 20 healthy volunteers received cardiac magnetic resonance (CMR). Peak systolic left ventricular (LV) longitudinal, radial, and circumferential strain and strain rate [LV strain longitudinal (LVSL), LV strain radial (LVSR), LV strain circumferential (LVSC), LV strain rate longitudinal (LVSRL), LV strain rate radial (LVSRR), and LV strain rate circumferential (LVSRC)], along with late gadolinium enhancement (LGE), perfusion deficit, and CALs in related segments were analyzed. The KD group was subdivided by CALs, perfusion, and LGE results, and strain results were compared with controls and in subgroups.

RESULTS

Cardiac fibrosis and ischemia were not confined to the territory of CALs. In a global analysis, strain and strain rates were lower in the KD group, especially in the subgroup with LGE and perfusion deficit. In segmental analysis, LVSR, LVSC, LVSL, and LVSRR decreased in the giant aneurysm group, and a lower LVSR (20.369%±10.603% vs. 26.071%±12.349%) and LVSC (-13.37%±5.365% vs. -15.847%±5.778%) were observed in thrombosed segments. The strain and strain rate were all lower in segments with LGE and perfusion deficit, and no obvious difference was found between groups with and without stenosis. LVSR had a better ability to identify giant aneurysm, thrombosis, stenosis, perfusion deficit, and LGE.

CONCLUSIONS

We detected lower strain values in KD patients, which was more pronounced in segments with aneurysm, thrombi, LGE, and perfusion deficit. LVSR is useful to discern patients with higher risk.

Association of left ventricular systolic dysfunction with coronary artery dilation in Kawasaki disease patients: Assessment with cardiovascular magnetic resonance

PURPOSE

To quantify global and regional left ventricular (LV) strain parameters in patients with Kawasaki disease (KD) using cardiovascular magnetic resonance (CMR) tissue tracking and assess the association of coronary artery dilation (CA dilation) with LV systolic dysfunction.

METHODS

Thirty-one KD patients with CA dilation, 22 patients without CA dilation and 27 age- and sex-matched normal controls underwent 3.0 T CMR examination. Z score of >2 was defined as CA dilation. Global LV strain parameters and regional LV strain parameters in 16 American Heart Association segmentation, including radial, circumferential and longitudinal peak strain (PS) and LV function were measured and compared among groups.

RESULTS

No significant difference in LV ejection fraction has been observed among controls, KD patients with CA dilation and without CA dilation (all p > 0.05). However, global longitudinal PS (GLPS) was lower in groups with CA dilation than those without CA dilation (-12.6 ± 4.1% vs -14.9 ± 2.6%, p < 0.05). For regional strain parameters, the segments with CA dilation (n = 301) were lower than those in both normal controls (n = 416) and segments without CA dilation (n = 547) in regional radial, circumferential and longitudinal PS (all p < 0.05). The severity of CA dilation was positively correlated to GLPS and regional longitudinal PS (r = 0.388 and r = 0.222; both p < 0.05) in KD patients. After adjusting for clinical characteristics, the multivariate analysis demonstrated that Z score was independently associated with GLPS in KD patients (β = 0.469, p = 0.000, model R2 = 0.355).

CONCLUSIONS

CMR tissue tracking could sensitively identify subclinical LV dysfunction in KD patients with CA dilation. LV systolic dysfunction occurs particularly in the myocardium dominated by the dilated coronary artery. CA dilation is an independent predictor of LV systolic dysfunction.

Assessing left ventricular systolic function in children with a history of Kawasaki disease

BACKGROUND

The incidence of Kawasaki disease (KD) is increasing. Indeed, KD has become the most common cause of acquired heart disease in children. Previous studies have well summarized the acute phase left ventricular (LV) systolic dysfunction using speckle tracking echocardiography (STE); however, changes in LV systolic function after long-term follow-up remain unclear.

METHODS

One hundred children with a history of KD, but without coronary artery aneurysms, were enrolled. These children were divided into two subgroups based on the presence or absence of coronary artery dilatation (CAD). The duration of follow-up was > 7 years. The control group consisted of 51 healthy children. The LV myocardial strain were measured by two- and three-dimensional STE.

RESULTS

Two-dimensional STE not only revealed that LV longitudinal strain decreased in part of segments in both KD groups, but also showed that global strain decreased in the KD group with CAD compared to the controls (P < 0.05). Global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and global area strain (GAS) were obtained by 3D STE. Compared to the controls, GLS and GAS decreased in both KD groups (P < 0.05). GCS and GRS decreased in the KD group with CAD, but was unchanged in the KD group without CAD (P < 0.05).

CONCLUSIONS

LV systolic dysfunction in children with KD and CAD was more severe than KD children without CAD compared to healthy children. This dysfunction can be assessed by LV regional and global myocardial strain using two- and three-dimensional STE.

Biomarkers of Inflammation and Fibrosis in Kawasaki Disease Patients Years After Initial Presentation With Low Ejection Fraction

Background Coronary artery aneurysms and myocarditis are well-recognized complications of Kawasaki disease (KD) but no systematic evaluation of the consequences of myocarditis has been performed in the subset presenting with low ejection fraction (EF). We postulated that more severe myocardial inflammation as evidenced by low EF during the acute phase could lead to late myocardial fibrosis. Methods and Results We measured the carboxyterminal propeptide of procollagen type I (PIPC), soluble suppressor of tumorigenicity 2, galectin-3 (Gal-3), growth-differentiation factor-15, and calprotectin by ELISA in late convalescent blood samples from 16 KD patients who had an EF ≤55% on their initial echocardiogram. Results were compared with samples from sex- and age-matched KD patients with initial EF >60%. In the univariate analysis, the median Gal-3 and PIPC levels in the low EF group were significantly higher than those in the normal EF group (Gal-3: low EF 6.216 versus normal EF 4.976 mg/dL P=0.038, PIPC: low EF 427.4 versus normal EF 265.2 mg/dL, P=0.01). In a multivariable analysis, there were significant differences for Gal-3 and PIPC levels between the low and normal EF groups, adjusting for age, sex, and worst z score. Conclusions Convalescent KD patients with a history of low EF during the acute illness had significantly elevated levels of Gal-3 and PIPC when compared with matched-control KD patients with normal EF. These findings raise concern for myocardial fibrosis as a potential late sequela of the more severe myocarditis experienced by a subset of KD patients during the acute phase.