Kensuke Karasawa

Dobutamine stress echocardiography for detection of coronary artery stenosis in children with Kawasaki disease

OBJECTIVES This study was designed to assess the feasibility and diagnostic accuracy of dobutamine stress echocardiography for detection of coronary artery stenosis in children with Kawasaki disease. BACKGROUND Dobutamine stress echocardiography is valuable as an alternative test for detection of coronary artery disease in adult patients; however, its usefulness for children has been demonstrated only in limited cases. METHODS Dobutamine stress echocardiography (up to 30 microgram/kg body weight per min) was performed in 50 patients at the convalescent stage of Kawasaki disease, including 26 patients with coronary sequelae documented by previous coronary angiography (sequelae group, 3 to 15 years old) and 24 patients with normal coronary arteries documented by echocardiography (normal group, 7 to 16 years old), who underwent quantitative coronary angiography on a separate day. Left ventricular regional wall motion divided into 16 segments was assessed in relation to the extent of coronary artery disease. A positive test response was defined as a new or worsened wall motion abnormalities. RESULTS Significant coronary artery disease (> or = 50% diameter stenosis of major vessels) was present in 21 patients in the sequelae group. There was no significant difference in the maximal dose of dobutamine between the sequelae and normal groups ([mean +/- SD] 22.4 +/- 5.1 vs. 24.2 +/- 2.5 microgram/kg per min). Heart rate and systolic blood pressure were significantly increased (p < 0.01) at maximal dose of dobutamine compared with values at rest in both groups; consequently, the rate-pressure product exceeded 20,000 in 20 (40%) of the 50 patients during dobutamine infusion. Ten patients had self-limiting side effects; however, there were no serious complications from stress-induced ischemia. New wall motion abnormalities corresponding to the extent of coronary artery disease were detected in 19 of 21 patients in the sequelae group, whereas no wall motion abnormalities were detected in the normal group. Thus, the sensitivity and specificity of dobutamine stress echocardiography for the detection of coronary artery disease were 90% and 100%, respectively. CONCLUSIONS We conclude that dobutamine stress echocardiography is a safe and accurate diagnostic method for detection of coronary artery stenosis in Kawasaki disease. Moreover, this is a possible alternative method for patients unable to exercise adequately, even if they are small children.

Guidelines for diagnosis and management of cardiovascular sequelae in Kawasaki disease

Over 35 years have elapsed since the first case of Kawasaki disease was described in 1967. 1 As they grow older, many patients with a history of Kawasaki disease are treated in departments of internal medicine rather than in pediatric departments. This disease has been extensively studied throughout the world, and many reports have been published on its etiology and cardiovascular sequelae. While the causes of Kawasaki disease unfortunately remain unknown, its cardiovascular sequelae have been intensively studied, contributing to the establishment of their pathology, natural history, diagnosis, and treatment. This provided the impetus for the Japanese Circulation Society to prepare a set of guidelines. The latest guidelines for the diagnosis of Kawasaki disease, as revised in 2002, are shown in Table 1. These are used to diagnose the disease in its acute phase. The diagnostic guidelines may be useful in adults with an unknown history of Kawasaki disease when the illness is suspected from the morphology of any coronary artery aneurysms. In preparing the present guidelines for the cardiovascular sequelae of Kawasaki disease, the first issue addressed was the classification of the size and severity of coronary artery aneurysms using standardized criteria. The consensus criteria shown in Table 2 were prepared according to the conventional classification and the opinions of specialists.

Characteristics of earlier atherosclerotic involvement in adolescent patients with Kawasaki disease and coronary artery lesions: Significance of gray scale median on B-mode ultrasound

OBJECTIVE To test the hypothesis that textural changes in the carotid intima-media complex (IMC) detected by B-mode ultrasound are associated with the difference of remodeling process in earlier atherosclerotic involvement in patients with Kawasaki disease (KD) and coronary artery lesions (CALs). METHODS Eighteen patients with KD and CALs (mean age 17.2 years), 17 patients with heterozygous familial hypercholesterolemia (FH) (mean age 16.9 years) and 15 age-matched healthy controls (Cont) were assessed and compared for carotid intima-media thickness (CIMT), elastic property (E(p)), and first- and second-order statistics. RESULTS KD showed significantly higher gray scale median (GSM) than FH and Cont. KD and FH showed significantly higher CIMT, entropy and lower angular second moment than Cont, but no significant difference was found between KD and FH. CONCLUSION Higher GSM in KD may indicate alteration of tissue components and heterogeneity of IMC, suggesting the development of arteriosclerotic vascular remodeling after vasculitis. This is distinct from that of atherosclerosis with lower GSM often observed in FH.

Measurement of Coronary Flow Reserve in Children by Transthoracic Doppler Echocardiography

Noninvasive measurement of coronary flow reserve was performed by transthoracic color Doppler echocardiography in 28 children with Kawasaki disease.

Non-invasive measurement of coronary flow reserve in children with Kawasaki disease

Objective: To investigate whether transthoracic Doppler echocardiography (TTE) can reliably measure the coronary flow reserve in the left anterior descending coronary artery in children with Kawasaki disease. Design: Coronary flow velocity in the distal left anterior descending coronary artery was measured by TTE and was compared with that obtained by intracoronary Doppler guide wire. The ratio of maximum hyperaemia (intravenous administration of adenosine triphosphate, 160 μg/kg/min) to baseline peak (mean) diastolic coronary flow velocity in the distal artery was used as an estimate of coronary flow reserve. Setting: University hospital. Patients: 10 patients with significant left anterior descending coronary stenosis (> 70% diameter stenosis) (group A) in the proximal or middle portion of the artery and 14 patients (group B) without significant stenosis, all with Kawasaki disease documented by previous coronary angiography. Results: The reduced hyperaemic coronary flow velocity in group A compared with group B resulted in a markedly lower coronary flow reserve, derived from both peak diastolic velocity and mean diastolic velocity by either technique of investigation. Multivariate analysis identified the best predictor of left anterior descending coronary artery stenosis to be a coronary flow reserve of ≤ 2.2, derived from mean diastolic flow velocity measured using TTE (sensitivity 90%, specificity 100%, accuracy 96%). A good correlation was found between diastolic velocity derived values for coronary flow reserve measured using both TTE and Doppler guide wire (r = 0.92, p = 0.0001). Conclusions: Coronary flow reserve in the distal left anterior descending coronary artery can be accurately measured using TTE without any intravascular instrumentation in children with Kawasaki disease.

Japanese consensus guidelines for pediatric nuclear medicine. Part 1: Pediatric radiopharmaceutical administered doses (JSNM pediatric dosage card). Part 2: Technical considerations for pediatric nuclear medicine imaging procedures.

Abstract The Japanese Society of Nuclear Medicine has recently published the consensus guidelines for pediatric nuclear medicine. This article is the English version of the guidelines. Part 1 proposes the dose optimization in pediatric nuclear medicine studies. Part 2 comprehensively discusses imaging techniques for the appropriate conduct of pediatric nuclear medicine procedures, considering the characteristics of imaging in children.

Lipoprotein (a) and apolipoprotein A‐1 and B in schoolchildren whose grandparents had coronary and cerebrovascular events: A preliminary study of 12–13 year old Japanese children

The aim of this study was to evaluate the relationship between the serum levels of lipoprotein (a) [Lp (a)] and apolipoproteins (apo A‐1 and apo B) in schoolchildren with a history of coronary and cerebrovascular events in their grandparents.

Assessment of coronary artery abnormalities in a patient with Kawasaki disease by multislice computed tomography

The high spatial resolution of multislice computed tomography (MSCT) permits direct visualization of the coronary artery system. In this report, we describe coronary artery abnormalities in a young adult with Kawasaki disease. MSCT detected a giant coronary artery aneurysm, coronary artery stenosis in the first diagonal artery, and a multi-layered structure in the right coronary artery and the left circumflex artery. These findings corresponded well to those obtained by coronary angiography. MSCT has the potential to be the standard diagnostic tool for the follow-up evaluation of coronary artery disease in adolescents and young adults with Kawasaki disease.

Detection of myocardial contractile reserve by low-dose dobutamine quantitative gated single-photon emission computed tomography in patients with Kawasaki disease and severe coronary artery lesions

We studied 24 patients with severe coronary artery lesions to assess myocardial perfusion and left ventricular contractile reserve simultaneously using low-dose dobutamine quantitative electrocardiographically gated single-photon emission computed tomography in patients with Kawasaki disease. Low-dose dobutamine infusion was started after an injection of technetium-99m tetrofosmin at rest. Myocardial contractile reserve was evaluated using the post-stress and low-dose dobutamine images, and myocardial perfusion was evaluated using the stress and rest images. Quantitative electrocardiographically gated single-photon emission computed tomography during low-dose dobutamine infusion is a useful and safe method for the combined evaluation of myocardial contractile reserve and myocardial perfusion.

MDCT of the anomalous origin of the right coronary artery from the left sinus of Valsalva associated with bicuspid aortic valve

Anomalous origin of the right coronary artery is a relatively rare coronary artery anomaly which is known to cause myocardial ischemia and sudden death. Association of anomalous origin of the right coronary artery with congenital bicuspid aortic valve is even rarer with only a few cases being reported previously. We describe, for the first time, MDCT findings of anomalous origin of the right coronary artery associated with congenital bicuspid aortic valve.