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.
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