Variant angina pectoris: a clinical and coronary arteriographic spectrum

The clinical course and coronary arteriographic findings in eight patients with Prinzmetal's variant angina pectoris are reviewed and contrasted to previously reported cases. In six patients with S-T-elevation inferiorly, three had normal coronary arteriograms, one had complete right coronary artery occlusion, one had diffuse triple-vessel disease, and one did not undergo coronary arteriography. In two patients with S-T-elevation anteriorly, severe stenosis of the anterior descending coronary artery was present. Medical treatment in four patients and surgical revascularization of the anterior descending coronary artery in two patients were both accompanied by marked symptomatic improvement. Spontaneous loss of angina occurred in two patients. During 17 months' mean follow-up, seven patients have remained free of angina and one died suddenly. Variant angina pectoris may be accompanied by a variety of coronary arteriographic findings and the prognosis appears more favorable than previously reported.     

Variance stabilization for computing and comparing grand mean waveforms in MEG and EEG

Grand means of time‐varying signals (waveforms) across subjects in magnetoencephalography (MEG) and electroencephalography (EEG) are commonly computed as arithmetic averages and compared between conditions, for example, by subtraction. However, the prerequisite for these operations, homogeneity of the variance of the waveforms in time, and for most common parametric statistical tests also between conditions, is rarely met. We suggest that the heteroscedasticity observed instead results because waveforms may differ by factors and additive terms and follow a mixed model. We propose to apply the asinh‐transformation to stabilize the variance in such cases. We demonstrate the homogeneous variance and the normal distributions of data achieved by this transformation using simulated waveforms, and we apply it to real MEG data and show its benefits. The asinh‐transformation is thus an essential and useful processing step prior to computing and comparing grand mean waveforms in MEG and EEG.     

Continuous electrocardiographic monitoring in patients with unstable angina pectoris: Identification of high-risk subgroup with severe coronary disease,variant angina,and/or impaired early prognosis

We assessed the value of two-channel Holter monitoring during the initial hours of hospitalization in patients with unstable angina pectoris (UAP) to identify those with severe coronary artery disease (CAD), variant angina, and/or poor prognosis over the next 3 months. Accordingly, 116 UAP patients had Holter monitoring for 27 ± 7 (mean ± SD) (range 12 to 50) hours following hospitalization. Of these, 24 evolved myocardial infarction (MI) during monitoring and 92 did not. Transient ST segment alterations occurred in 21 of the 92. Of these 21, 4 had variant angina, were treated with calcium antagonists, and did well. Each of the remaining 17 had severe fixed CAD (left main or three-vessel) (n = 12) and/or poor prognosis over the 3 months after discharge as manifested by death (n = 1), MI (n = 3), and/or severe angina (n = 3). In contrast, 71 patients did not demonstrate transient ST segment alterations: none had variant angina (p < 0.001), nine had left main or three-vessel CAD (p < 0.001), and 50 were alive and well 3 months after discharge (p < 0.001). Ventricular tachycardia (VT) was demonstrated by Holter monitor in 5 of the 92 patients: four had three-vessel CAD and the other had severe persistent angina. Thus in patients hospitalized with unstable angina, transient ST segment alterations and/or VT on Holter monitor are specific predictors of “high-risk” subgroup UAP patients with left main or three-vessel CAD, variant angina, and/or impaired 3-month prognosis.     

京杭大运河丹阳段及丹金溧漕河沿线钉螺时空分布特征研究

目的　分析京杭大运河江苏丹阳段及丹金溧漕河沿线钉螺时空分布特征,为动态评估该区域钉螺扩散风险提供科学依据。方法　收集2012－2017年研究区域内水网型血吸虫病流行区螺情数据,采用缓冲区分析、空间自相关分析、热点分析及标准差椭圆分析法,探索京杭大运河丹阳段及丹金溧漕河沿线钉螺时空变化趋势。结果　2012－2017年,研究区域内有螺环境数呈上升趋势;有螺环境主要分布于丹金溧漕河1 000 m缓冲区内,特别是京杭大运河与丹金溧漕河交汇处的老九曲河沿线。2014、2016、2017年,研究区域内钉螺分布存在空间自相关,热点区域主要为丹金溧漕河与京杭大运河交汇处;钉螺分布整体呈东北-西南方向,随着时间变化逐渐向南北方向转变。结论　京杭大运河丹阳段及丹金溧漕河沿线钉螺空间分布复杂,存在从上游向下游扩散的风险,需加强该区域的灭螺工作。     

Imaging Intussusception in Children’s Hospitals in the United States: Trends,Outcomes, and Costs

ObjectiveTo describe imaging utilization, outcomes, and cost in the management of intussusception between 2010 and 2017 in pediatric hospitals in the United States.MethodsAll children (under 18 years of age) with a primary diagnosis of intussusception in a large administrative database were identified. Demographics, imaging, and costs were described.ResultsThere were 17,032 children (63.3% boys, 36.7% girls, mean age: 3.2 years) that had 20,655 hospital encounters for intussusception, and 88.5% were <5 years of age. The average length of stay was 2.8 days (median: 1 day), with rates of intensive care unit admission, 3.7%; 90-day readmission, 10.5%; and mortality, 0.2%. The surgical rate was 19.6%, and 93.5% (n = 19,301) of patients underwent imaging: 87.2% (n = 16,822) received ultrasound, 69.1% (n = 13,329) had fluoroscopy, 59% (n = 11,380) had abdominal radiographs, and 8.8% (n = 1,696) had CT. The reduction success rate for fluoroscopy was 77.9%. Surgery was more common in rural patients (26.8% versus 18.7% in urban patients, P < .001). Median encounter costs were $2,675 (interquartile range: $1,637-$5,465). Imaging cost represented a quarter (median $680, interquartile range: $372-1,069) of all costs. Higher costs (median) were associated with longer length of stay (<3 days: $858 versus >3 days: $5,342; use of CT ($4,168 versus $943 in patients without a CT), and surgery ($4,434 versus $860 without surgery).ConclusionThe management of intussusception is mainly nonsurgical, most frequently involving imaging with ultrasound and fluoroscopy, and resulting in excellent outcomes in the great majority of the cases. Despite playing a central role for diagnosis and management, imaging only represents a fraction of total cost.     

Facilitators and Barriers to Healthy Pregnancy Spacing among Medicaid Beneficiaries: Findings from the National Strong Start Initiative

Background

Closely spaced, unintended pregnancies are common among Medicaid beneficiaries and create avoidable risks for women and infants, including preterm birth. The Strong Start for Mothers and Newborns Initiative, a program of the Center for Medicare and Medicaid Innovation, intended to prevent preterm birth through psychosocially based enhanced prenatal care in maternity care homes, group prenatal care, and birth centers. Comprehensive care offers the opportunity for education and family planning to promote healthy pregnancy spacing.

Atrioventricular node reentry: Intravenous verapamil as a method of defining multiple electrophysiologic types

Fourteen patients with recurrent supraventricular tachycardia (SVT) underwent electrophysiological evaluation. Each patient was shown to have reentry confined to the region of the atrioventricular (AV) node. Verapamil, 0.075 to 0.15 mg/kg was administered intravenously to each patient during a stable episode of SVT, resulting in termination in each instance. There was more than one mechanism for termination of SVT. Nine patients showed termination by anterograde AV node block preceded by an increase in conduction time in the anterograde limb of the tachycardia circuit (Ae-H intervals) with no change in the conduction time in the retrograde limb (H-Ae intervals). Three patients showed termination by block in the retrograde limb of the circuit preceded by increases in both Ae-H and H-Ae intervals. An additional example of termination by spontaneous ventricular premature complexes and usurpation by sinus rhythm were also seen. Common features were that verapamil had significant effects on anterograde and retrograde conduction and refractoriness in the AV node. It prolonged the refractory periods of both fast and slow pathways in patients with dual anterograde AV node pathways, and observable effects on retrograde conduction and refractoriness were seen even in patients with constant ventriculoatrial conduction times during incremental ventricular pacing in a control study. However, three distinct groups of patients were identified on the basis of their response to ventricular pacing in a control study and upon verapamil effects recorded during their SVT. An explanation for these latter findings may be that there is a normal variation in the retrograde response of parts of the AV node to ventricular pacing, and a variability in some of the patients' responses to verapamil.     

Metabolic responses of the heart in acute myocardial infarction in man

Acute myocardial infarction evokes a characteristic neurohumoral response: Catecholamine release is increased, plasma contents of free fatty acids and glucose are elevated and glucose tolerance is diminished. To what degree the myocardium participates in this stress response was evaluated by sampling coronary sinus and arterial blood in 50 patients with acute transmural infarction. Studies were initiated an average of 8 hours after the clinical onset of infarction and were continued for up to 60 hours. A total of 173 separate metabolic studies were analyzed. Forty-one percent exhibited a pattern of predominant myocardial free fatty acid uptake (mean extraction ratio 24 percent) in the presence of elevated plasma free fatty acid and glucose contents (respective means 1,181 μmol/liter and 210 mg/100 ml). Myocardial extraction ratios for glucose, lactate and pyruvate were low (respective means 1.1, 4 and 11 percent). Twenty-one percent of the studies revealed normal myocardial metabolism and 18 percent showed enhanced carbohydrate uptake, as evidenced by increased myocardial extractions of lactate and pyruvate (respective means 42 percent) and of glucose (mean 5 percent). Plasma contents of glucose and free fatty acids were lower than in the predominant free fatty acid group (respective means 156 mg/100 ml and 743 μmol/liter). The remaining 20 percent of studies showed high plasma substrate contents and low myocardial substrate uptake suggesting metabolic breakdown. The free fatty acid metabolic pattern was observed in more than 50 percent of the studies performed at the time of or close to the occurrence of important clinical complications. Propranolol, 0.1 mg/kg intravenously, shifted myocardial substrate utilization from free fatty acids toward carbohydrates. The myocardial respiratory quotient increased from an average of 0.79 to 0.88 (P < 0.01).The study demonstrates that the metabolic patterns of the myocardium are influenced by the systemic response to stress. Beta adrenergic blockade changed substrate utilization of the myocardium, supporting the hypothesis that adrenergic activation plays an important role in these metabolic responses.