Autonomic and Peripheral Nerve Function in Adolescents With and Without Diabetes

In this study reference ranges were established for autonomic and peripheral nerve tests in 122 non-diabetic adolescents. Regression analysis was used to evaluate the effect of age and gender on neurological function. Increasing age was associated with: less heart rate variability during deep breathing (p = 0.03), higher thermal threshold for cold at the wrist (p = 0.009), and higher vibration threshold at the toe (p = 0.001) and medial malleolus (p = 0.01). Male gender was associated with higher Valsalva ratio (p = 0.0004), higher thermal threshold for hot at the foot (p = 0.002), and higher vibration threshold at the malleolus (p = 0.03). The REFVAL programme was used to determine parametric or non-parametric reference limits: the 5% limits for autonomic and 95% limits for peripheral tests. One hundred and eighty-one adolescents with diabetes were studied under identical conditions and similar effects of age and gender were found. Twenty-eight percent of the group with diabetes had at least one abnormal autonomic test result out of four (expected 18.5%); 24% had at least one abnormal peripheral test result out of six (expected 26.5%). Glycaemic control was associated with autonomic (p = 0.04) but not peripheral abnormalities. Using multiple regression analysis and adjusting for age and gender, there was no effect of diabetes duration or glycaemic control on neurological function.     

Autonomic Dysfunction and Silent Myocardial Ischaemia on Exercise Testing in Diabetes Mellitus

The incidence and mechanism of painless myocardial ischaemia on exercise testing in diabetic patients is not clear. Therefore, two studies were performed. Retrospectively, all exercise tests carried out in our hospital during the past 5 years were reviewed for silent ischaemia. Prospectively, diabetic patients with known or suspected coronary artery disease underwent autonomic function testing and a second exercise test. Of 1653 exercise tests reviewed, 247 were positive (ST depression > 0.1 mV). Of the 29 diabetic patients with positive tests 20 (69%) had painless ST depression, compared with 77 (35%) of the 218 non-diabetic patients (p < 0.001). The diabetic patients with painful and painless ST depression were comparable for age, sex, therapy, but the 20 with no pain on exercise testing had a longer duration of diabetes and a higher incidence of microvascular complications than the 9 with pain (70 vs 22%, p < 0.05). In the prospective study, 12 of 30 diabetic patients with positive exercise tests had pain in association with ST depression and 18 had no pain. Six patients had mild and 12 severe autonomic neuropathy on formal testing. Twelve had no autonomic dysfunction. Eleven (92%) of 12 patients with severe neuropathy had painless ST depression, compared with 7 (39%) of 18 without severe neuropathy (p < 0.01). Thus, silent myocardial ischaemia on exercise testing is common among patients with diabetes mellitus and is associated with severe autonomic dysfunction.     

Mortality in Diabetic Patients with Cardiovascular Autonomic Neuropathy

Cardiovascular autonomic diabetic neuropathy (CADN) may carry an increased risk of mortality. However, in previous studies the prognosis of patients with CADN seemed to be influenced by life-threatening macro- and microvascular complications which had already been present at the start of the study period. Between 1981 and 1983, 1015 diabetic patients have been examined for CADN (abnormal heart rate variation at rest and during deep respiration) at the Diabetes Research Institute, Düsseldorf. Thirty-five patients (28 with Type 1 diabetes, 7 with Type 2 diabetes) with CADN have been retrospectively recruited and reviewed 8 years later and compared with 35 patients without CADN who were matched for sex, age, and duration of diabetes. Exclusion criteria for entry into the study included severe micro- or macrovascular complications, such as proliferative retinopathy, proteinuria or symptomatic coronary artery disease. During the 8-year observation period, 8 patients with CADN and 1 patient without CADN died. The survival rate estimates steadily declined in patients with CADN over the whole period studied. The 8-year survival rate estimate in patients with CADN was 77 % compared with 97 % in those with normal autonomic function (p < 0.05). Deaths were mainly due to macrovascular diseases (n = 3) and sudden unexpected deaths (n = 3). One patient with CADN died after an episode of severe hypoglycaemia. Among the deceased patients, coefficient of variation of R-R intervals during deep breathing was significantly reduced when compared with those who survived (1.04 ± 0.5 % vs 1.87 ± 1.0 %; p < 0.05), and symptoms of autonomic neuropathy (orthostatic hypotension, gastroparesis, gustatory sweating) were more frequent (7/8 vs 10/27 patients). The mean QTc interval was not different between the groups. These results suggest a relatively poor prognosis of patients with CADN in the absence of clinically detectable micro- and macrovascular complications.     

Prospective Assessment of Autonomic and Peripheral Nerve Function in Adolescents with Diabetes

Autonomic and peripheral nerve function were studied prospectively in 102 adolescents with Type 1 diabetes over a 5-year period. All adolescents were assessed three times; 54 were assessed four times. The median age at baseline was 14.5 (range 10.4–18.0) yr. The median diabetes duration at baseline was 6.8 (range 1.3–15.2) yr. Autonomic nerve function was assessed by measuring heart rate variation during deep breathing, valsalva manoeuvre, standing from a lying position (30/15 ratio), and the postural change in systolic blood pressure. Peripheral nerve function was assessed by determining the thermal threshold for heat and cold at the wrist and foot and the vibration threshold at the great toe and medial malleolus. At baseline, 29.5 % adolescents had at least one abnormal autonomic nerve test and 28.4 % had at least one abnormal peripheral nerve test. There was no significant increase in the number of abnormalities over the study period. Persisting abnormalities were present in only six individuals. Abnormalities were not related to age, diabetes duration or glycaemic control. In summary, a low rate of neurological abnormalities was found, suggesting that more than 3 years of follow-up is required to detect evolving neuropathy in this age group.     

Dietary Recommendations for Children and Adolescents with Diabetes: An Implementation Paper

General Recommendations 1. Children with diabetes mellitus have the same basic nutritional requirements as other children. 2. Dietary recommendations should be based on good eating habits for the whole family. Radical changes in diet involving unusual foods or eating patterns for the child with diabetes alone are not appropriate. 3. Energy requirements of children vary widely and the energy content of the diet should be based on what the child usually eats. The diet should be reviewed regularly to meet the changing needs of growth and physical exercise without obesity. 4. The insulin regimen should, as far as is possible, be chosen to fit the child's daily lifestyle and preferred eating habits. Insulin type, dose, and frequency should be reviewed with the diet as the child develops. 5. Regular distribution of meals and snacks throughout the day remains the most important way to avoid extremes of hyperglycaemia and hypoglycaemia. This distribution should be based on an exchange system, using handy measures and taking into account food and meal type, the particular insulin regimen and the child's exercise patterns and usual eating habits. Currently this exchange system is based on carbohydrate foods but in the future the energy and fat contents will need further consideration. 6. Most special ‘diabetic foods’ are unnecessary. Low calorie sweeteners, as used in low calorie fruit squashes and fizzy drinks, are useful. 7. Children with diabetes from specific ethnic minority groups, or on vegan diets or living in deprived circumstances require special dietary attention for their diabetes. Those with coexisting chronic disorders such as cystic fibrosis or coeliac disease, should receive dietary advice from professionals with specialist knowledge. 8. Translating the principles of diabetic dietary management into a varied diet, arranged readily by the parents and eaten by the child, is demanding. It can best be met by a skilled dietitian working in close co-operation with child, parents, diabetes specialist nurse and doctor. Infancy 9. The diet should not differ from that of infants without diabetes. Breast feeding should be encouraged or a standard infant formula-feed used. Solids may be introduced from 3–6 months, but breast milk or a modified infant formula is encouraged as part of the increasingly mixed diet to at least the end of the first year. 10. Diabetes is rare in infancy so expert advice should be sought from dietitians experienced in paediatric diabetes. Under fives 11. After 2 years of age the diet should slowly be changed to one relatively low in fats, with unrefined carbohydrate foods, fitting family customs and meeting energy needs. 12. Fully skimmed cow's milk contains insufficient vitamins A and D, too little fat and therefore energy for the under-fives. However, semi-skimmed milk can safely be included in a nutritionally adequate diet from the age of 2 years. 13. Vitamin supplementation may be given to children aged from 1 month to 5 years according to needs and local practice for all children. There are no specific additional requirements for the under-fives with diabetes. School children 14. Reduction of fat intake, especially of saturated fats, is expected to reduce risk of coronary heart disease and stroke in later life. After 5 years of age fat intake should be reduced to around 35–40 % of total energy. 15. Replacing energy from fat by eating half or more of the daily food energy as carbohydrate, principally from unrefined, fibre-rich sources, may improve both short- and long-term health. Dietary carbohydrate for the child with diabetes should never be restricted below the usual family intake (usual range 45–50% of calories). 16. School children should be encouraged to select their carbohydrate from sources that are rich in soluble fibre with physical structure intact (e.g. whole fruit, oats, porridge, peas, beans, and lentils). These have been shown to improve glycaemic control. 17. Consumption of rapidly absorbed carbohydrate in the form of simple sugar such as fruit juice and sweets or refined starch such as mashed potato in isolation, should be discouraged. However, when used in conjunction with other nutrients within a meal, simple sugars and refined starch improve palatability without worsening metabolic control. 18. The use of sugars to prevent or treat hypoglycaemia should be established on an individual basis. 19. The proportion of energy taken as protein should not be increased among children with diabetes compared with their normal peers. 20. Supplements of minerals and vitamins are not required where a good balance of foods is taken. 21. Regular exercise should be encouraged, and insulin dose reduced or extra dietary energy provided as indicated by individual blood glucose monitoring.     

Prospective Study of Autonomic Nerve Function in Type 1 and Type 2 Diabetic Patients: 24 Hour Heart Rate Variation and Plasma Motilin Levels Disturbed in Parasympathetic Neuropathy

To clarify the impact of autonomic neuropathy in diabetic patients, we have conducted a prospective study of 58 Type 1 and 51 Type 2 diabetic patients (investigated at baseline, after 4, and after 7 years). In Type 1 diabetic patients, the sympathetic nerve function (orthostatic acceleration and brake indices) and in Type 2 patients, parasympathetic nerve function (R-R interval variation; E/I ratio) deteriorated during 7 years of prospective observation. Symptoms of autonomic neuropathy were associated with signs of autonomic neuropathy (low brake indices) in Type 1 but not in Type 2 diabetic patients. In the latest assessment 24 h ECG recording was performed and blood samples assayed for neuropeptide Y (NPY) and motilin were obtained. Type 1 diabetic patients with parasympathetic neuropathy (abnormal E/I ratio) showed significantly lower SD value (less variation in the R-R intervals; 29 [17] vs 50 [16], [mean {interquartile range}]; p = 0.001) and higher postprandial plasma motilin values (70 [20] pmol I^?1 vs 50 [15] pmol I^?1; p< 0.01) than patients with normal parasympathetic nerve function. In Type 2 diabetic patients, sympathetic neuropathy (low brake indices) was associated with an increased frequency of ventricular extra systolic beats during 24 h ECG recording (r_s = 0.65; p<0.01). Postprandial plasma NPY levels were not associated with disturbed autonomic nerve function.     

Does Abnormal QT Interval Prolongation Reflect Autonomic Dysfunction in Diabetic Patients? QTc Interval Measure Versus Standardized Tests in Diabetic Autonomic Neuropathy

The question as to whether the QTc interval correlates with five cardiovascular tests (deep breathing test, 30/15 ratio test, lying to standing test, cough test, and postural blood pressure test) for the diagnosis of diabetic autonomic neuropathy (DAN) was investigated in 168 (38 Type 1, 130 Type 2) consecutive outpatients (mean age 54.9 ± 11.2 years). QT interval was measured on an ECG recorded at rest and QTc calculated according to Bazett's formula. The percentage of patients with a QTc greater than 0.440 s was: absent DAN = 11% (n = 7), probable DAN = 7% (n = 4), definite DAN = 23% (n = 12) (p < 0.05), and the mean (± SD) QTc values were 0.403 ± 0.028 s, 0.405 ± 0.023 s, and 0.421 ± 0.026 s, respectively. A significant correlation between QTc duration and DAN score of autonomic cardiovascular test results (r = 0.34, p < 0.0001) was observed. The calculated specificity, sensitivity, positive and negative predictive values were 89%, 15%, 70% and 37%, respectively. In conclusion, QTc can be considered as an additional specific test in the assessment of diabetic autonomic neuropathy, but cannot replace the standard battery of cardiovascular tests.     

QT Interval Length and Diabetic Autonomic Neuropathy

QT interval length was measured in ECG recordings from three groups of age-matched male subjects: 36 normal subjects, 41 diabetic patients without (DAN-ve), and 34 with (DAN+ve) autonomic neuropathy. ECG samples were selected from previously recorded 24-h ECGs on the basis of a clearly defined T wave and a steady RR interval over 2 min of around 750 ms (80 beats min^?1). There were no significant differences in RR interval between the groups. The two diabetic groups had slightly longer QT measurements (normal 365 ± 14 (±SD) ms, DAN-ve 373 ± 18 ms, DAN+ve 375 ± 23 ms, p = 0.05), and corrected QT (QTc) values (normal 423 ± 15 ms, DAN-ve 430 ± 20 ms, DAN+ve 435 ± 24 ms, p = 0.05). Ten diabetic patients fell above our defined upper limit of normal for QTc (>mean + 2SD). There was a significant correlation in the DAN-ve group between the QT indices and 24-h RR counts (QT r = ?0.38, p < 0.01; QTc r = ?0.40, p < 0.01). We conclude that there are some small alterations in QT interval length in the steady state in diabetic autonomic neuropathy. The changes appear to be due to autonomic impairment, rather than diabetes per se.     

Autonomic neuropathy and diabetic foot ulceration

Autonomic function was studied in three groups of insulin-dependent diabetic patients. Heart rate changes during deep breathing and on standing were significantly less in 28 patients with a recent history of foot ulceration compared with 40 patients with peripheral neuropathy but without ulceration (p less than 0.001) and 54 patients without neuropathy (p less than 0.001). Sympathetic function was assessed in 36 of these patients from peripheral arterial diastolic flow patterns obtained by Doppler ultrasound measurements and expressed as the pulsatility index (PI). Patients with a history of ulceration (n = 10) showed considerably increased diastolic flow (PI = 4.28 +/- 0.53, mean +/- S.E.M.) compared with 12 neuropathic patients with no history of ulceration (PI = 7.80 +/- 0.68, p less than 0.002) and 14 patients without neuropathy (PI = 9.55 +/- 0.89, p less than 0.002). Severely abnormal autonomic function occurs in association with neuropathic foot ulceration, but patients without ulcers have lesser degrees of autonomic neuropathy, thus a causal relationship has not been established.     

Diabetes Mellitus but not Impaired Glucose Tolerance is Associated with Dysfunction in Peripheral Nerves

To clarify whether long-term impaired glucose tolerance (IGT) is associated with dysfunction of peripheral and autonomic nerves, age-matched men with IGT and diabetes mellitus were followed prospectively for 12–15 years, when peripheral and autonomic nerve function was assessed. The patients comprised four subgroups: (1) 51 IGT subjects (duration of IGT at least 12–15 years); (2) 35 diabetic patients, with IGT 12–15 years ago, who later developed diabetes; (3) 34 diabetic patients, duration of diabetes at least 12–15 years; and (4) 62 age-matched non-diabetic control subjects. Mean age of the whole study population was 61±2 years (mean ±SD), not different in the four groups. Peripheral nerve function tests included nerve conduction velocities, amplitudes, distal latencies, F-reflexes, and sensory perception thresholds for heat, cold, and vibration. Autonomic nerve function tests included the heart rate reaction during deep breathing (expiration to inspiration ratio) and to tilt (acceleration and brake indices). Despite 12–15 years of IGT, peripheral nerve function did not differ between IGT and control subjects, whereas autonomic nerve function deviated; an abnormal expiration to inspiration ratio (a sign of vagal nerve dysfunction) was significantly more common (15/51 versus 5/62;p<0.01) in IGT than in control subjects. Diabetic patients (groups 2 and 3) showed lower conduction velocities (in general 2–4 m s^?1 lower) than IGT and control subjects in all tested nerves. In conclusion, diabetes but not IGT, is associated with peripheral nerve dysfunction.     

Cardiovascular,Metabolic, and Hormonal Responses to Noradrenaline in Diabetic Patients with Autonomic Neuropathy

Denervation hypersensitivity is a well-known phenomenon in patients with autonomic failure. In diabetic autonomic neuropathy hypersensitivity to β-adrenergic stimulation has been demonstrated. We infused noradrenaline, mainly an α-adrenoceptor agonist, in three escalating doses (0.5, 2.5, and 5 μg min⁻¹) in three age and sex matched groups of eight subjects: healthy volunteers, diabetic patients with and without autonomic neuropathy. During steady state in each infusion period we measured heart rate, blood pressure, cardiac output, hepato-splanchnic blood flow, vascular resistance, glucose kinetics, metabolites (β-hydroxybuturate, glycerol, and lactate), and glucoregulatory hormones (noradrenaline, adrenaline, growth hormone, pancreatic polypeptide, cortisol, and insulin). Systolic and mean blood pressure increased in all groups but diabetic patients with autonomic neuropathy showed a significantly higher increase (p < 0.01) than the other two groups, with a lower threshold for increase in blood pressure. Cardiac output, hepato-splanchnic blood flow, vascular resistance, and heart rate did not change in any of the groups. The incremental increase in glucose and β-hydroxybuturate was higher in patients with autonomic neuropathy. Otherwise, only minor changes were seen in hormonal and metabolic parameters. The cardiovascular hypersensitivity seen in diabetic autonomic neuropathy was mainly explained by increased peripheral vascular resistance, which increased significantly (p < 0.05) more in these patients. In conclusion, diabetic patients with autonomic neuropathy show denervation hypersensitivity to α-adrenergic stimulation by noradrenaline, especially as regards cardiovascular effects.     

学龄儿童动脉顺应性的年龄性别分布及相关因素

目的:探讨学龄儿童自然人群动脉顺应性(AC)的基本特点和相关影响因素。方法:采取分层整群抽样方法,在北京一所全日制学校每年级随机抽取一个班,通过问卷排除患心血管疾病个体后, 对其余学生进行体量、血压、青春发育情况检测。采用Pulsetrace指端脉搏波测量仪测定动脉硬化指数(SI),并以此判断被测者AC的情况(AC与SI呈反比),每人重复测量3次,取平均值进行分析。共检测6-17岁儿童288名(男161名, 女127名,平均年龄11．16±2．92岁)。结果:男女生的SI没有差异。SI呈现出随年龄增加而下降的趋势(即AC随年龄增加而升高)。10岁之前AC的上升速度显著高于10岁之后;而青春期发育启动前AC的上升速度也明显高于青春期发育成熟后。多元回归分析的结果显示,年龄、收缩压和体重指数与SI的偏回归系数具有统计学意义。结论:随着年龄的增长,学龄儿童的AC逐渐上升。建议结合年龄和青春发育水平来建立儿童期AC的参照值。     

Catecholamines and Diabetic Autonomic Neuropathy

In diabetic patients with autonomic neuropathy plasma noradrenaline concentration, used as an index of sympathetic nervous activity, is low. This decrease is, however, only found in patients with a long duration of diabetes with clinically severe autonomic neuropathy. This apparent insensitivity of plasma catecholamine measurements is not due to changes in the clearance of catecholamines in diabetic autonomic neuropathy. The physiological responses to infused adrenaline and to noradrenaline are enhanced, for noradrenaline mainly cardiovascular responses. Adrenoceptors (alpha and beta adrenoceptors) are not altered in circulating blood cells in diabetic autonomic neuropathy. Thus, a generalized up-regulation of adrenoceptors does not occur in diabetic autonomic neuropathy.     

Development and Progression of Diabetic Retinopathy: Adolescents at Risk

The aims of this study were to evaluate short-term changes in retinopathy in adolescents, and to examine the relationship of these changes to risk factors. Two-hundred and three adolescents, with a median age of 14.5 (range 10.4 to 20.6) yr and a median duration of diabetes of 6.6 (1.1 to 16.3) yr, were included in the study. Retinopathy was assessed on two occasions, using stereoscopic fundus photography; the median time between assessment was 1.3 (0.5 to 3.0) yr. At baseline, 41 % of the adolescents had background retinopathy. When patients were stratified according to the median diabetes duration (DD) (6.6 yr) and glycaemic control over the 12 months prior to assessment (HbA_1c) (8.4 %), the percentage of retinopathy in each group was: lowDD/lowHbA_1c 13 %; lowDD/highHbA_1c 40 %; highDD/lowHbA_1c 42 %; and highDD/highHbA_1c 72 %. Using a 2-step criteria for stability or change in retinopathy, 11 % of the 203 adolescents showed progression of retinopathy, 41 % had stable retinopathy, 5 % showed regression, and 43 % had no retinopathy at either assessment. Change in retinopathy was related to age at baseline assessment (borderline significance, p = 0.06), diabetes duration (p < 0.001), glycaemic control (p < 0.001) and total cholesterol (p = 0.04), and was also related to DD/HbA_1c group membership (X²p < 0.001). This study highlights the combined adverse effect of long diabetes duration and poor glycaemic control on the development and progression of retinopathy during adolescence, and identifies a group that is likely to show progression over a relatively short period.     

Autonomic Dysfunction in Non-insulin-dependent Diabetes Mellitus and Fibrocalculous Pancreatic Diabetes in South India

The prevalence of cardiovascular autonomic dysfunction in non-insulin-dependent (Type 2) diabetes mellitus (NIDDM) and fibrocalculous pancreatic diabetes (FCPD) was assessed by a standard battery of autonomic dysfunction tests involving heart rate responses and blood pressure responses. Three hundred and thirty-six patients with NIDDM and 40 patients with FCPD were studied. Logistic regression analysis was done to look for risk factors associated with autonomic dysfunction. Abnormalities of autonomic function tests were detected in 120 NIDDM patients (35.7 %) and 9 FCPD patients (22.5 %). There was no significant difference in severity of autonomic dysfunction between NIDDM and FCPD groups. There was an increase in prevalence of autonomic dysfunction with age and duration of diabetes both in NIDDM and FCPD. In the 0–5 years duration group, 28.2 % of NIDDM and 16.6 % of FCPD had evidence of disordered autonomic function and these figures increased to 56.2 % and 60 % respectively, after 16–20 years duration of diabetes. Logistic regression analysis showed that only peripheral dysfunction was associated with autonomic dysfunction in NIDDM patients (r = 0.66, p = 0.02).     

Subclinical Left Ventricular Longitudinal and Radial Systolic Dysfunction in Children and Adolescents with Type 1 Diabetes Mellitus

Introduction: There are few studies of subclinical systolic dysfunctions in children and adolescents with type 1 diabetes mellitus (DM), and so the available data are limited. The aim of this study was to determine early echocardiographic signs of LV systolic dysfunction in children and adolescents with type 1 DM using two‐dimensional speckle tracking echocardiography (2DSTE). Material and Methods: The study included 84 children and adolescents with type 1 DM and 32 sex‐, age‐, and body mass index–matched healthy subjects. The LV functions were assessed using conventional echocardiography, tissue Doppler imaging, and 2DSTE. Results: The results showed LV diastolic dysfunction as reflected by significantly increased A‐wave velocity, decreased E/A ratio, and increased early filling deceleration time in the patients with diabetes (P = 0.02, P = 0.029, and P = 0.04; respectively). Compared with the control group, patients with diabetes showed significantly lower values for longitudinal systolic strain and strain rate in most segments of the LV; for radial strain values of the LV; for lateral circumferential strain and posterior and anterolateral circumferential strain rate of the LV; and for global longitudinal and radial strain of the LV. Global longitudinal and radial strain values of the LV were significantly lower among patients with poor glycemic control than in the control group. Conclusion: In addition to diastolic dysfunction, LV longitudinal and radial function was found to be impaired in asymptomatic children and adolescents with type 1 DM who have normal LV ejection fraction by 2DSTE. Glycemic control may be the main risk factor for alteration of myocardial function.     

儿童和青少年快速性心律失常的临床特点

研究儿童和青少年快速性心律失常的临床特点。选择 1995～ 2 0 0 2年在我院行射频消融 (RFCA)治疗的儿童和青少年快速性心律失常患者 ,共 32 1例 ,男 2 10例、女 111例 ,年龄中位数 13.4± 3.6 (1.5～ 18)岁 ;其中 ,房室折返性心动过速 (AVRT) 2 0 4例、房室结折返性心动过速 (AVNRT) 74例、特发性室性心动过速 (IVT) 35例、房性心动过速 (AT) 5例、心房扑动 (AFL) 2例、不适当窦性心动过速 (IST) 1例。记录所有病例术前未发作心动过速及心动过速发作时的体表 12导联心电图 ,结合电生理检查 ,分析其临床特点。结果 :AVRT、AVNRT和IVT分别占6 3.6 %、2 3.1%和 10 .9%。年岁较小的儿童和青少年 ,右侧旁道较多 ,随着年龄的增加 ,左侧旁道相对越来越多。B型预激合并多旁道较常见。 35例IVT ,其中 2 3例为左室IVT ;6例为右室IVT。 12例合并先天性心脏病 ;13例并发心动过速性心肌病 ,心功能及心脏大小在RFCA术后 3～ 6个月恢复正常。结论 :①AVRT、AVNRT和IVT是儿童和青少年快速性心律失常中最常见的 3种类型。②心动过速性心肌病经早期适当的治疗是可逆的。     

糖尿病消化不良患者的自主神经功能及其对近端胃功能的影响

背景:神经病变是糖尿病患者的常见并发症。研究表明糖尿病消化不良患者存在近端胃功能障碍,但糖尿病自主神经病变对近端胃功能的影响尚不清楚。目的:了解糖尿病消化不良患者的自主神经功能及其对近端胃功能的影响。方法:23例糖尿病消化不良患者和10名健康志愿者分别行自主神经功能测定(标准心血管反射试验)和近端胃功能测定(水负荷试验),以B超测量近端胃(胃底)和远端胃(胃窦)的横截面周长和面积。结果:糖尿病消化不良组自主神经功能异常者占95.7%,其交感、副交感和自主神经功能计分均显著高于健康对照组,副交感神经功能受损更为明显。糖尿病消化不良组的阈值饮水量和饱足饮水量均较健康对照组显著减少(518.04ml±205.52ml对640.00ml±154.20ml,887.39ml±277.17ml对1185.00ml±266.72ml,P<0.05),饱足饮水量与饱足饮水后近端胃面积的变化呈正相关(r=0.441,P=0.035),交感神经功能计分与饱足饮水后近端胃周长的变化呈负相关(r=-0.566,P=0.005)。结论:糖尿病消化不良患者有明显的自主神经功能异常,其中副交感神功能受损更为明显,且近端胃感觉阈值减低,适应性舒张功能减退。糖尿病患者近端胃功能障碍可能与自主神经功能受损有一定关系。