Attilio Turchetta

Ambulatory blood pressure monitoring in children with aortic coarctation and kidney transplantation.

BACKGROUNDnAmbulatory blood pressure monitoring (ABPM) has been found to be of significant importance in clinical practice because numerous blood pressure (BP) measurements may be made throughout the 24-hour period.nnnOBJECTIVEnTo assess the clinical utility of ABPM in children with secondary hypertension.nnnMETHODSnWe studied 37 patients (21 boys and 16 girls), with a mean age of 16.4 +/- 4.1 years, after kidney transplantation and 38 patients (27 boys and 11 girls), with a mean age of 10.2 +/- 2.1 years, after surgical correction of aortic coarctation. Data, expressed as mean +/- SD, were analyzed after dividing the patients into 4 groups. Group A consisted of 25 patients receiving antihypertensive therapy; group B included 12 patients not receiving antihypertensive therapy. Group C included 25 patients operated on before 3 years of age (8 +/- 7 months of age); group D included 13 patients operated on after 3 years of age (74 +/- 29 months of age).nnnRESULTSnIn groups A and B, casual BP measurement showed that 16 of 37 patients (43%) were hypertensive; 24-hour ABPM detected a larger number of patients who were hypertensive (23 of 37, 62%); there were 18 in group A and 5 in group B. In groups C and D, casual BP measurement identified 6 of 38 (15%) patients as hypertensive, whereas 24-hour ABPM again identified a higher number (13 of 38, 34%).nnnCONCLUSIONSnOur findings confirm that 24-hour ABPM is more sensitive than casual BP in detecting abnormal BP in patients at high risk for secondary hypertension.

Pulmonary Function and Ventilatory Limitation to Exercise in Congenital Heart Disease

Pulmonary function in older children and adolescents following surgical repair of congenital heart disease is often abnormal for various reasons. Many of these patients report symptoms of exercise intolerance although the reason(s) for this symptom can be complicated and sometimes interrelated. Is it simply deconditioning due to inactive lifestyle, chronotropic or inotropic insufficiency? or could there indeed be ventilatory limitation to exercise? These are the questions facing the clinician with the increasing frequency of patients undergoing repair early in life and growing into adulthood. Understanding pulmonary functional outcomes and means of determining ventilatory limitation to exercise is essential to thoroughly address the problem. This article reviews pulmonary function in patients with congenital heart disease and then describes a newer technique that should be applied to determine ventilatory limitation to exercise.

Exercise Testing and 24-Hour Ambulatory Blood Pressure Monitoring in Children with Williams Syndrome

The aim of the study was to assess workload capacity and blood pressure (BP) response to treadmill exercise and 24-hour BP monitoring in children with Williams syndrome. Seventeen children were examined (8 males and 9 females) whose mean age was 13.8 ± 3.6 years. Six patients were on antihypertensive therapy. Each patient underwent clinical examination and measurement of BP at rest, during exercise, and during 24-hour monitoring. Two-dimensional echocardiogram and echo-Doppler of renal arteries were performed. The test was stopped for muscular fatique or reduced cooperation. The patients, when compared to a population of healthy children, had reduced total time of exercise (7.3 ± 1.9 vs 14.3 ± 2.6 min, p < 0.001) and, at the same workload, increased heart rate (167 ± 19 vs 145 ± 16 beats/min, p < 0.001) and increased maximum systolic BP (146 ± 27 vs 128 ± 12 mmHg, p = 0.01). Ambulatory blood pressure measurement values showed higher systolic blood pressure both during daytime and nighttime. Our study confirms that children and adolescents with Williams syndrome are at high risk for hypertension, probably related to the alterations of large arteries. The data relating to the synthesis of elastin may have a direct relationship to the compliance of the arterial system, leading to hypertension.

Cardiorespiratory functional assessment after pediatric heart transplantation

Abstract: Limited data are available on the exercise capacity of young heart transplant recipients. The aim of this study was therefore to assess cardiorespiratory responses to exercise in this group of patients. Fourteen consecutive heart transplant recipients (six girls and eight boys, age‐range 5–15u2003yr) and 14 healthy matched controls underwent a Bruce treadmill test to determine: duration of test; resting and maximum heart rates; maximum systolic blood pressure; peak oxygen consumption (VO2 peak); and cardiac output. Duration of test and heart rate increase were then compared with: time since transplantation, rejections per year, and immunosuppressive drugs received. The recipients also underwent the following lung function tests: forced vital capacity (FVC) and forced expiratory volume in 1u2003s (FEV1). When compared with healthy controls, transplant recipients had tachycardia at rest (126u2003±u20033.7 beats/min; pu2003<u20030.001); significantly reduced tolerance (9.3u2003±u20030.4u2003min; pu2003<u20030.001), a maximum heart rate of 169u2003±u20035.4 beats/min (pu2003<u20030.05); a cardiac output of 5.65u2003±u20030.6u2003L/min (pu2003<u20030.05); and a lower heart‐rate increase from rest to peak exercise (pu2003<u20030.001) but a similar VO2 peak. The heart‐rate increase correlated significantly with time post‐transplant (ru2003=u20030.55; pu2003<u20030.05), number of rejection episodes per year (ru2003=u2003−u20030.63; pu2003<u20030.05), and number of immunosuppressive drugs (ru2003=u2003−u20030.60; pu2003<u20030.05). The recipients had normal FVC and FEV1 values. After surgery, few heart transplant recipients undertake physical activity, possibly owing to over‐protective parents and teachers and to a lack of suitable supervised facilities. The authors stress the importance of a cardiorespiratory functional evaluation for assessment of health status and to encourage recipients, if possible, to undertake regular physical activity.

Early left ventricular abnormality/dysfunction in obese children affected by NAFLD

BACKGROUND AND AIMSnAlthough it is generally accepted that non alcoholic fatty liver disease (NAFLD) is linked to increased risk of cardiovascular disease, the presence of abnormalities in cardiac function among NAFLD children is limited and controversial. Aim of the study was to detect cardiac abnormalities/dysfunction in a paediatric population of NAFLD.nnnMETHODS AND RESULTSnAnthropometric, laboratory, cardiovascular fitness, 24 h blood pressure monitoring and Doppler echocardiography parameters were obtained in 50 untreated children (37 males; mean age 12.2 + 2.5) with biopsy-proven NAFLD. Abnormalities in both cardiac function and geometry could be identified in the whole study population: prevalence of about 35% in left ventricular hypertrophy, 14% of concentric remodelling and 16% of left atrial dilatation. Furthermore children with NAFLD (NAS score <5) showed lower cardiac alterations compared to NASH patients (NAS score >5). After adjusting for age, sex and BMI, a positive correlation was found only between LV mass and NAS score (p < 0.001).nnnCONCLUSIONnOur results suggest that cardiac dysfunction can be detectable early in NAFLD children and this is not linked to cardiovascular and metabolic alteration, other than to liver damage. Although as a preliminary stage, we can speculate a possible direct relationship between liver and heart steatosis, already occurring during childhood.

Efficacy and safety of ventricular rate responsive pacing in children with complete atrioventricular block

Single chamber rate responsive pacing offers many potential advantages over the more complex dual chamber atrial tracking pacing mode in children, and the preservation of atrioventricular synchrony could be unnecessary in selected groups of pediatric patients. Twenty‐two pediatric patients (age range 9 months to 12 years; mean 6.5 years) had implantation of ventricular rate responsive (VVIR) pacemakers over a 2‐year period. All patients had chronic third‐degree atrioventricular block, and a normal ventricular function at rest. During the follow‐up each patient underwent a 24‐hour Holter monitoring, and ten performed a graded treadmill test in both ventricular fixed rate (VVI) and rate responsive (VVIR) pacing mode. Paced ventricular rates were found to be normal for age in all 22 patients; maximum rate did not reach the higher programmed rate during daily activities in any patient. Comparing the mean paced ventricular rate to the mean rates of blocked P waves, six patients showed a difference of more than 20 beats/min, which induced the pacemaker parameters to be reprogrammed. In all patients a significant correlation was found between variations of paced ventricular rate and variations of spontaneous blocked atrial rhythm (P < 0.05); this correlation persisted in the subsequent Holter controls in the ten patients with longer follow‐up. Exercise tolerance resulted normal in the ten patients who performed a treadmill test either in VVIR or VVI mode, with increased maximal heart rates and maximal systolic blood pressure in VVIR mode (P < 0.0013). Rate responsive ventricular pacemakers seem to adequately respond to the physiological needs of daily life of this selected group of children requiring permanent pacing.

Cardiovascular Hemodynamics: Relationships with Insulin Resistance in Obese Children

AbstractWe investigated blood pressure (BP), cardiac output (CO), and systemic vascular resistance (SVR) and their relationships with insulin and glucose blood levels in a group of 24 obese children (mean age, 11.9 ± 2.1 years; 19 males). The data were compared to those obtained from a group of 19 healthy controls of the same age (12.4 ± 2.1 years; p = NS; 13 males). nBP at rest was measured and all subjects underwent an exercise testing on the treadmill (Bruce Prot.), time of exercise, maximal heart rate, maximum systolic blood pressure, CO, and SVR at rest and at peak exercise were considered. Only in the OC group were an oral glucose tolerance test were performed to calculate insulin sensitivity index (ISI) and echocardiography performed to determine the left ventricular mass (LVM). The relationships between cardiovascular and metabolic parameters were investigated. Student’s t-test and linear regression analysis were used when appropriate. OC had a significant reduction in TE and higher BP, and linear regression analysis showed significant correlations between BP, ISI, and LVM. We speculate that OC need a regular cardiovascular and metabolic screening to prevent the development of early cardiovascular damage.

Insulin resistance and exercise capacity in male children and adolescents with non-alcholic fatty liver disease.

Insulin resistance (IR) and obesity may be associated with impaired response to physical exercise. We aimed at assessing physical capacity in obese children with biopsy proven non-alcoholic fatty liver disease (NAFLD) as compared to normal weight and obese children without fatty liver disease. All male subjects, 20 NAFLD and 31 control individuals (20 obese, without NAFLD and 11 normal weight children) took part in the study. We evaluated changes in cardiovascular parameters during a bicycle–ergometer exercise test (James’ test). Duration, power of exercise, heart rate (HR), blood pressure (BP), pulse pressure, cardiac output (ICO) and total peripheral vascular resistance indexed for height (ITPVR) were recorded at rest (r) and peak (p) exercise. The homeostatic model assessment was used to determine insulin resistance (HOMA-IR) and beta-cell action (HOMA-beta cell). In NAFLD and obese subjects, fasting leptin, insulin secretion, insulinogenic index (IGI), muscle insulin sensitivity (MISI) and hepatic insulin resistance index (HIRI) were assayed. Children with NAFLD were the most insulin-resistant (Pxa0=xa00.001), and showed higher HIRI than obese controls (Pxa0=xa00.05). At rest, they had the lowest values of SBPr (Pxa0=xa00.001 vs. controls and Pxa0≤xa00.05 vs. obese controls); during the test, the highest values of ICOp (Pxa0=xa00.005), ΔICO (Pxa0=xa00.003) and ΔTRVPp (Pxa0≤xa00.0001). NAFLD and obese controls both had impaired ΔHRp (Pxa0≤xa00.0001). However, obese controls were not able to reduce peripheral resistance during the test. HOMA-IR explained 28% of variance in ΔICO of the whole sample, (Pxa0≤xa00.0001). In obese children with or without NAFLD, increased IR and body weight may induce cardiovascular compensatory changes in response to physical exercise with fairly different pathogenetic mechanisms, which are likely to be dependent on the different degree of IR.

Mid-term results, and therapeutic management, for patients suffering hypertension after surgical repair of aortic coarctation.

We designed our study to investigate the efficacy of a new therapeutic approach to late onset hypertension in patients after surgical repair of aortic coarctation. Several studies have shown a higher incidence of hypertension during daily activities, and during exercise, in patients after surgical correction of coarctation. To the best of our knowledge, however, no data exists concerning haemodynamics, the response of arterial pressures, and the effects of medications for lowering blood pressure during exercise or during daily activities.We studied 128 patients, aged 15.6 +/- 4.3 years, to determine the response of blood pressure as we administered treatment in the attempt to achieve a normotensive state. We excluded patient with associated cardiac abnormalities, apart from those with bicuspid aortic valves. We evaluated blood pressure at rest in both the right arm and leg to establish presence of any gradient, as well as the blood pressure in the arm during exercise testing, and by 24-hour ambulatory monitoring.Atenolol was prescribed for those with elevated values of blood pressure but with a normal increment of heart rate during exercise. We prescribed Candesartan for those with elevated levels of blood pressure but with reduced increments of heart rate, specifically maximal heart rates of less than 85% of their predicted value. Both drugs were used when one alone was not effective. We found that, in young patients, candesartan provided better control of blood pressure with no side-effects, especially as demonstrated using 24-hour ambulatory monitoring, while atenolol was less effective, with more side-effects. Our experience suggests that both drugs should be used in patients who are non-responsive to monotherapy.

Abnormal Hypertensive Response during Exercise Test in Normotensive Transplanted Children and Adolescents

We investigated the cardiovascular and respiratory conditions, at rest and in response to stress testing, in 10 children and adolescents with successful renal transplantation, to release certifications for participation in sports. Our patients were aged more than 6 years, transplanted 6 months or more before the study, with creatinine clearance > 40 ml/min/1.73 m2, without hypertension at rest. All but 1 were on cyclosporine A, prednisone and azathioprine. Two control study groups with the same chronological age and body surface area were paired with our patients. They underwent a graded exercise tread-mill test, during which maximal blood pressure and heart rate were recorded. Resting electrocardiogram, dynamic 24-hour electrocardiogram Holter monitoring and mono- and bidimensional echocardiograms were obtained before the test. Spirometry was performed to study lung flow and volume. A questionnaire collected information about physical activity patterns. Four categories, according to practice, frequency and duration of exercise, were identified: nonactive, starters, experienced and very experienced. Most children and adolescents were sedentary or mildly interested in sports and during treadmill test we observed reduced exercise capacity and systolic hypertensive response to increasing exercise testing.