Increased vascular constriction has been observed at the site of atherosclerotic lesions, suggesting an association between atherosclerosis and altered vascular tone. While atherosclerosis may increase sensitivity to exogenous vasoconstrictors, little is known about the response of normal and atherosclerotic coronary arteries to an exogenous stimulus that excites the sympathetic nervous system. Therefore, we studied the response to cold pressor test (CPT) using quantitative angiography and Doppler flow velocity measurements in eight patients with angiographically normal coronary arteries (group I), nine patients with mild coronary atherosclerosis (< 50% diameter narrowing) (group II), and 13 patients with advanced coronary stenoses (> 50% diameter narrowing) (group III). In 31 segments of angiographically smooth arteries in group I, the CPT produced vasodilation from a control mean diameter of 2.68 ± 0.09 (mean ± SE) to 2.99 ± 0.09 mm at peak CPT (p < 0.001), a 12 + 1 % increase in diameter. In group II, 27 irregular segments constricted to peak CPT from a mean control diameter of 1.82 ± 0.12 to 1.66 ± 0.12 mm (p < .001), a 9 ± 1% decrease, while 10 smooth segments dilated from a mean control diameter of 1.98 ± 0.11 mm to 2.34 ± 0.15 mm (p < .01), a 19 + 2% increase in diameter. Likewise, in group III, the 17 stenotic segments constricted from 1.16 ± 0.09 to 0.89 ± 0.09 mm (p < .001), a 24 6% decrease; the irregular segments also constricted from 2.44 0.11 to 2.22 0.12 mm (p = .002), a 10 ± 2% decrease. In contrast, two smooth segments dilated from 2.98 to 3.23 mm (mean), an 8% increase in diameter. Coronary blood flow increased 65 ± 4% (mean) during CPT in group I, it increased 15 ± 6% in group II, and it decreased 39 ± 8% in group III. The vasodilator response in four normal patients was partly inhibited by the administration of intracoronary propranolol (17 + 3% increase during control, 10 + 2% increase after propranolol, 41% less dilation; p = .002). We conclude that the response of normal coronary arteries to the CPT test is dilation, in part related to /3-adrenoreceptor stimulation and possibly flow-mediated endothelial dilation or a2-adrenergic activity. The paradoxical vasoconstrictor response induced by atherosclerosis may represent altered catecholamine sensitivity and/or a defect in endothelial vasodilator function. The presence of atherosclerosis impairs vasodilator responses and thus may contribute to the pathogenesis of myocardial ischemia.

Kawasaki disease is an acute vasculitis of unknown etiology that predominantly affects children <5 years of age. Structural damage to the coronary arteries after the acute, self-limited illness is detected by echocardiography in approximately 25% of untreated patients. The long-term effects of the acute coronary arteritis are unknown. To define the spectrum of clinical disease in young adults that can be attributed to Kawasaki disease in childhood, we performed a retrospective survey of cases reported in the English and Japanese published data of adult coronary artery disease attributed to antecedent Kawasaki disease. The mean age at presentation with cardiac sequelae was 24.7 +/- 8.4 years (range 12 to 39) for the 74 patients identified with presumed late sequelae of Kawasaki disease. Symptoms at the time of presentation with cardiac sequelae included chest pain/myocardial infarction (60.8%), arrhythmia (10.8%) and sudden death (16.2%). These symptoms were precipitated by exercise in 82% of patients. One-third of the patients in whom a chest radiograph was taken had ring calcification. Angiographic findings included coronary artery occlusion (66.1%). Extensive development of collateral vessels was reported in 44.1% of patients. Autopsy findings included coronary artery aneurysms (100%) and coronary artery occlusion (72.2%). The acute vasculitis of Kawasaki disease can result in coronary artery damage and rheologic changes predisposing to thrombus formation or progressive atherosclerotic changes that may remain clinically silent for many years. Coronary artery aneurysms and calcification on chest radiography were unusual features in this group of patients. A history of antecedent Kawasaki disease should be sought in all young adults who present with acute myocardial infarction or sudden death.

Objectives To describe the characteristics of hospitalizations for patients who utilize clinical programs that provide care coordination for children with multiple, chronic medical conditions. Study design Retrospective analysis of 1,083 patients hospitalized between June 2006 and July 2008 who utilize a structured, pediatric complex-care clinical program within four children's hospitals. Chronic diagnosis prevalence (technology assistance, neurologic impairment and other complex chronic conditions), inpatient resource utilization (length of stay, 30-day readmission), and reasons for hospitalization were assessed across the programs. Results Over the two year period, complex-care program patients experienced a mean 3.1 (SD 2.8) admissions, 12.2 days (SD 25.5) in the hospital per admission, and a 25.4% thirty-day hospital readmission rate. Neurologic impairment (57%) and presence of a gastrostomy tube (56%) were the most common clinical characteristics of program patients. Notable reasons for admission included major surgery (47.1%), medical technology malfunction (9.0%), seizure (6.4%), aspiration pneumonia (3.9%), vomiting / feeding difficulties (3.4%), and asthma (1.8%). Conclusions Hospitalized patients who utilized a structured clinical program for children with medical complexity experienced lengthy hospitalizations with high early readmission rates. Reducing hospital readmission may be one potential strategy to lower inpatient expenditures in this group of children with high resource utilization.

This tertiary care-primary care partnership model improved health care and reduced costs with relatively modest institutional support.

Dilator reserve of the coronary microvasculature is diminished in patients with dilated cardiomyopathy. Although increased extravascular compressive forces, tachycardia, and increased myocardial mass can explain some impairment, recent evidence suggests the possibility of intrinsic microvascular disease. We tested the hypothesis that impairment of endothelium-dependent dilation of the microvasculature could be a contributing mechanism. We infused the endothelium-dependent dilator acetylcholine (Ach) (10-8 to 10-6 M) and the smooth muscle vasodilator adenosine (AD) (10-6 to 10`-M) into the left anterior descending coronary artery in eight patients with dilated cardiomyopathy (mean ejection fraction, 28%) and seven controls (atypical chest pain). Small In seven control patients receiving both Ach and AD, 56±9%o of the maximal AD flow response was attained with the endothelium-dependent vasodilator Ach, whereas in seven cardiomyopathy patients receiving both Ach and AD, only 23±14% of the maximal AD response was attained (p<0.01). Thus, endothelium-dependent vasodilator function is impaired in the coronary microvasculature of patients with dilated cardiomyopathy. There might be pathogenetic links between dysfunction of the endothelium and myocardial failure. (Circulation 1990;81:772-779) C oronary flow reserve is diminished in patients with dilated cardiomyopathy (DC).1-5 Elevated filling pressures, increased heart rate, decreased coronary perfusion pressure, and increasing left ventricular mass out of proportion to micro-

Kawaski disease (KD) is an acute, self-limited vasculitis that typically occurs in young children and was first described by Japanese pediatrician Tomisaku Kawasaki in 1967. Although originally thought to be a rare condition, KD has become the most common cause of acquired heart disease in the pediatric age group in developed countries. The majority of patients with KD appear to have a benign prognosis but a subset of patients with coronary artery aneurysms are at risk for ischemic events and require lifelong treatment. In the four decades that have passed since the initial recognition of KD, the number of patients reaching adulthood has continued to grow. Adult cardiologists will be increasingly involved in the management these patients. Currently, there are no established guidelines for the evaluation and treatment of adult patients who have had KD. We review here the current literature that may be helpful to clinicians who care for adults who suffered from KD in childhood.

This study investigated the vasodilator function of endothelium that regenerated after balloon angioplasty and the relation of this function to the extent of vascular injury and to subsequent intimal proliferation. Balloon angioplasty was performed in the left iliac artery of 47 New Zealand White rabbits. Vascular responses were examined in vitro 2 and 4 weeks after a "severe" injury (3.0-mm balloon) or a "moderate" injuiry (2.5-mm balloon). Both degrees of balloon injury caused complete endothelial denudation. Endothelial regrowth 2 weeks after either injury was confirmed histologically. Although the regenerated cells had irregular sizes and polygonal shapes and lacked the typical alignment in the direction of blood flow, immunocytochemical staining for factor VILI-related antigen identified these cells as endothelium. To study the vasodilator function of regenerated endothelium, rings of balloon-injured and control (contralateral) iliac arteries were suspended in organ chambers for recording of isometric force. Endothelium-dependent relaxation of balloon-injured vessels to acetylcholine and to the calcium ionophore A23187 were reduced at 2 and at 4 weeks after severe injury. After moderate injury, endothelium-dependent relaxations to these agents were reduced at 2 weeks but had normalized by 4 weeks. Endothelium-independent relaxation to sodium nitroprusside, however, was preserved in all study groups. Morphometric analysis revealed an inverse correlation between the degree of intimal thickening and maximal relaxation to acetylcholine (r=0.45,p<0.01). Thus, there is a persistent attenuation ofreceptor-and nonreceptor-mediated endothelium-dependent relaxations after arterial injury. The regenerated cells have an altered morphological appearance, but staining for factor VIII-related antigen confirms their endothelial origin. The degree and duration of endothelial dysfunction depends on the severity of the initial injury and is related to the extent of intimal thickness. (Circulation 1990;81:1667-1679 Normal endothelial function includes the formation of a semipermeable barrier that actively regulates coagulation, cell growth, and vasoreactivity.-4 Endothelium-derived relaxing

We studied the vasomotion of epicardial coronary arteries during exercise and tested the hypotheses that abnormal vasoconstriction is related to