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Biomedical subjects

M Bevilacqua

Publications and source records attributed to M Bevilacqua.

At least 19 recordsLinked to original sources
PubMed2006

Frequency rhythmic electrical modulation system (FREMS) on H-reflex amplitudes in healthy subjects.

AIM: Changes in the amplitude of Hoffmann reflex (H-reflex) may reflect variations in the characteristics of the largely monosynaptic circuitry that is explored and are a possible target for diagnostic and physical therapeutic intervention. However, previous attempts to induce predictable changes in the H-reflex amplitude by transcutaneous electrical nervous stimulation (TENS) have generally failed. Previous workers applied fixed frequency in the low- (2-5 Hz) or in the high- (100 Hz) field, but they did not attempt to vary frequency and/or impulse duration in time. METHODS: We evaluated the effect of a new type of painless electric stimulation, i.e. frequency rhythmic electrical modulation system (FREMS). FREMS is characterized by the use of transcutaneous electric pulses with sequentially modulated frequency (f: 1-39 Hz) and width (w: 10-40 micro s) at constant, perceptive threshold voltage (approximately 150 V). FREMS was applied at the abductor hallucis muscle (AHM), as conditioning stimulus of the H-reflex which was recorded ipsilaterally at the soleus muscle, according to the classic method, in 10 normal volunteers (age range 21-40 years). RESULTS: H-reflex amplitude was substantially decreased (-50%) during FREMS and H-reflex amplitude variations were influenced by w/f variation in time during FREMS subphase C in a predictable way (r(2)=0.43; P<0.001). Our results suggest an effective ability of FREMS to modulate H reflex amplitude. CONCLUSIONS: The ability to achieve large and predictable changes of the H-reflex amplitude simply by modulating both frequency and duration of a conditioning painless electrical stimulation offers new possibilities for the treatment of diseases characterized by motoneuron excitability abnormalities.

Action Potentials↗
PubMed2006

Treatment of morbid obesity by intraparietogastric administration of botulinum toxin: a randomized, double-blind, controlled study.

OBJECTIVE: The stomach is the main target organ for bariatric surgery, but no medical treatment has been developed to increase satiety and decrease food intake via gastric pathways. The aim of our study was to investigate whether or not the intraparietogastric administration of botulinum toxin A (BTX), able to modify the motility patterns of the stomach, could be useful for treatment of obesity. DESIGN: Double blind controlled study. SUBJECTS: Twenty-four morbidly obese patients (mean weight (s.e.m.) 116.1+/-4.89 kg, mean body mass index (BMI) 43.6+/-1.09 kg/m(2)) were blindly randomized to receive 200 IU BTX or placebo into the antrum and fundus of the stomach by intraparietal endoscopic administration. MEASUREMENTS: We evaluated weight loss, BMI changes, satiety score, the maximal gastric capacity for liquids and the gastric emptying time (octanoic acid breath test). RESULTS: The two groups were homogeneous for anthropometric characteristics. Eight weeks after treatment, BTX patients had significantly higher weight loss (11+/-1.09 vs 5.7+/-1.1 kg, P<0.001) and BMI reduction (4+/-0.36 vs 2+/-0.58 kg/m(2), P<0.001) and a higher satiety score on a visual analogic scale (7.63+/-0.38 vs 4.72+/-0.44, P<0.001) than controls. Furthermore, BTX patients showed a significantly greater reduction in maximal gastric capacity for liquids (266.6+/-48 vs 139+/-31, P<0.001) and a greater prolongation in gastric emptying time (+18.93+/-8 vs -2.2+/-6.9 min, P<0.05). No significant side effects or neurophysiologic changes were found. CONCLUSIONS: Topical intragastric BTX was effective in reducing food intake and body weight in morbidly obese patients.

Adult↗
PubMed2005

Bisphosphonates and atherosclerosis: why?

The increasing knowledge on bone calcification processes has revealed some similarities with vascular tissue, where calcifications of arteries and cardiac valves contribute to several cardiovascular problems, such as heart failure, systolic hypertension, and myocardial and peripheral ischemic disease. Bisphosphonates have been used extensively for over two decades for the treatment of diseases associated with excessive bone resorption, i.e., osteoporosis, osteolytic bone metastasis, hypercalcemia and Paget's disease, by blocking osteoclastic function. Etidronate, pamidronate and clodronate has been shown to inhibit the development of experimental atherosclerosis, and proposed mechanisms for this action include inhibition of arterial calcification and lipid accumulation, degradation of atherogenic LDL-cholesterol and reduced foam cell formation. Bisphosphonates inhibit various enzymes involved in cholesterol biosynthesis and suppress macrophages in atheromatous lesions. The possibility of pharmacological agents that effectively treat both osteoporosis and atherosclerosis is attractive, however, current evidence is not conclusive and further research is necessary to confirm these actions in the clinical setting.

Apoptosis↗
PubMed2005

Vertical banded gastroplasty modifies plasma ghrelin secretion in obese patients.

BACKGROUND: Restrictive bariatric surgery causes weight loss through substantial decline of appetite with satiety after meals. Reduction of plasma ghrelin levels after Roux-en-Y gastric bypass and laparoscopic adjustable gastric banding could contribute to these effects, although contradictory results have been reported. The only restrictive operation still not yet investigated is vertical banded gastroplasty (VBG). We studied the effects of VBG on basal plasma ghrelin levels and meal-mediated inhibition. METHODS: 12 morbidly obese patients, 11 female and 1 male, were studied before and after VBG, when the BMI fell by 20%. The control group consisted of 6 lean volunteers. Active ghrelin was determined by RIA after overnight fasting and after the administration of a liquid meal. RESULTS: Obese patients preoperatively had significantly lower basal plasma ghrelin levels than lean volunteers, and the meal did not inhibit ghrelin secretion. After VBG and 20% BMI loss, basal plasma ghrelin levels increased and the reduction caused by a meal recovered. CONCLUSIONS: Weight loss caused by VBG is associated with higher plasma ghrelin levels in obese patients. The operation restores the normal adaptation of the A- cells of the stomach to a meal.

Adult↗
PubMed2004

Long term follow up of children with myocarditis treated by immunosuppression and of children with dilated cardiomyopathy.

OBJECTIVE: To describe the treatment and long term outcome after immunosuppressive treatment of children with myocarditis. METHODS AND RESULTS: 114 patients with newly diagnosed dilated cardiomyopathy were divided into three groups, according to the histological pattern: group A, acute myocarditis; group B, borderline myocarditis; and group C, non-inflammatory cardiomyopathy. Groups A and B were treated with cyclosporine and prednisone in addition to conventional treatment. Survivors of the whole cohort were analysed for 13 year transplant-free survival and assessed for left ventricular function. Event-free survival at 13 years was 97 (3)% for group A, 70 (8)% for group B, and 32 (7)% for group C (p < 0.0001). It was 96 (4)% at one year and 83 (5)% at 13 years for the cumulated myocarditis group (A and B). Cardiac function recovered completely in 79% of survivors in group A, 64% in group B, and 36% in group C. The rate of complete recovery in the cumulated group (A and B) was 70%. CONCLUSIONS: The high long term survival rate of this cohort of children with myocarditis is probably due to the effect of short term immunosuppression. This result differs from previously published series of conventionally treated children, whose survival probability at one year was about 60%.

Analysis of Variance↗
PubMed2003

Prevalence of hypovitaminosis D in elderly women in Italy: clinical consequences and risk factors.

In order to evaluate the prevalence, risk factors, and clinical consequences of hypovitaminosis D in elderly Italian women a multicenter study of 43 osteoporosis centers from all regions of Italy was carried out. Study population included 700 women aged 60-80 years in whom blood was taken for 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) measurements. All subjects were also questioned to assess the prevalence of several risk factors for hypovitaminosis D, osteoporotic fractures and activities of daily living (ADL). Values of 25OHD lower than 5 ng/ml were found in 27% of the women and lower than 12 ng/ml in 76%. 25OHD and PTH levels were negatively correlated ( r=-0.38, after logarithmic transformation of both variables). 25OHD levels significantly declined with advancing age and number of pregnancies and were positively correlated with educational level (years spent at school), dairy calcium intake, and days spent on holiday by the sea. In a multivariate model including all these variables, the only one that remained significant was the level of education. The lowest age-adjusted 25OH D levels were found in smokers or in women living in central Italy as compared with those living in northern or southern Italy. The mean (+/-SD) age-adjusted 25OH D values were significantly lower in women who sustained a hip fracture (7.1+/-2.2 versus 11.0+/-9.9). Women with low 25OHD levels (<12 ng/ml) had worse scores for ADL and mobility ADL (move outdoors, use stairs, walk at least 400 m, carry a heavy object). Vitamin D deficiency is extremely common among elderly Italian women. Women with lower educational level, living in central Italy, smokers or with lower intake of dairy products are at greater risk. Hypovitaminosis D is associated with worsening of the ability to perform activities of daily living and higher hip fracture prevalence. This finding should lead to an urgent population-based strategy to remedy this condition.

25-Hydroxyvitamin D 2↗
PubMed2002

Immune monitoring of glucocorticoid therapy.

There is a clear medical need to improve the GC therapy because of the individually variable responsiveness to GC. Recently, several well-standardised cell-based assays focussing on monocyte functions (flowcytometric measurement of HLA-DR expression, semiautomatic measurement of ex vivo TNF release capacity) have been introduced into the clinical laboratory. These techniques allow for both the detection immunosuppression and the monitoring of therapeutic efficacy. The measurement of efficacy might be further improved by applying the novel technology of gene expression profiling that is ready for introducing into the diagnostics.

Drug Monitoring↗
PubMed2001

Amiodarone-induced torsade de pointes in a child with dilated cardiomyopathy.

Amiodarone has a high incidence of side effects, but few pro-arrhythmic effects. We report a case of amiodarone-induced torsade de pointes in a child aged 10 years. The patient had severe dilated cardiomyopathy, and even though he was treated with low oral doses of amiodarone, without dosage increments and electrolyte imbalance, he developed torsade de pointes at nights, after T-wave modification and increases of the corrected QT interval (QTc, 20%), QT dispersion (QTd, 175%) and QTcd (116%). The arrhythmic events were preceded by sinus bradycardia at Holter monitoring. Amiodarone therapy was discontinued. Intravenous magnesium administration was not effective in the suppression of torsade de pointes. High-rate atrial pacing prevented recurrences of the arrhythmias and reduced the QTc interval by 20%, QTd by 50%, and QTcd by 70%; QTd and QTcd returned below normal limits. This case underscores the need of careful electrocardiographic monitoring during amiodarone therapy.

Administration, Oral↗
PubMed2001

Permanent junctional reciprocating tachycardia in infants and children: effectiveness of medical and non-medical treatment.

BACKGROUND: The aim of this study was to identify, in children affected by permanent junctional reciprocating tachycardia (PJRT), the effective treatment. METHODS: Seventeen children (9 males, 8 females, mean age 59 +/- 62 months, median 24) affected by PJRT were referred to our Institute between the years 1987 and 2000. RESULTS: Pharmacological therapy was successfully used in 14 patients: flecainide and propranolol in 5 of them, amiodarone alone in 5 and associated with propranolol in 2, propafenone alone in 1 and in association with sotalol in 1. These drugs were given for a mean period of 54.5 +/- 49.8 months with resolution of the cardiomyopathy in 7/7 patients. Treatment had been continued for 3-6 months and there were no side effects. Nine patients were treated with radiofrequency transcatheter ablation, after 78 +/- 53.5 months of medical treatment, at a mean age of 150 +/- 16 months. The shortest endocardial ventriculo-atrial (VA) interval during tachycardia was recorded in all cases at the coronary sinus ostium (mean value of local VA-surface RP' interval -38 ms, range -24/-55 ms). Successful ablation of the anomalous pathway was obtained at this site in all patients (mean watts delivered 26 +/- 3 W, mean T degrees 64 +/- 5 degrees C). During the follow-up period (mean 21 +/- 17 months) 2 patients with recurrences of PJRT underwent a second successful procedure. CONCLUSIONS: PJRT in pediatric patients can be successfully treated with antiarrhythmic drugs, this may allow delay of the highly effective radiofrequency ablation treatment until the children have reached an adequate growth.

Adolescent↗
PubMed2001

Long-term effects of spinal cord stimulation on myocardial ischemia and heart rate variability: results of a 48-hour ambulatory electrocardiographic monitoring.

BACKGROUND: Spinal cord stimulation (SCS) has analgesic properties and may be used to treat pain in patients with therapeutically refractory angina who are unsuitable for myocardial revascularization. Some studies have also demonstrated an anti-ischemic effect. The aim of this study was to evaluate the long-term persistence of the effects of SCS on myocardial ischemia and on heart rate variability. METHODS: Fifteen patients (9 males, 6 females, mean age 76 +/- 8 years, range 58-90 years) with severe refractory angina pectoris (Canadian class III-IV), on optimal pharmacological therapy, unsuitable for myocardial revascularization and treated with SCS for a mean follow-up of 39 +/- 27 months (range 9-92 months) were studied. Eleven patients had had a previous myocardial infarction and 5 a coronary artery bypass graft. The mean ejection fraction was 54 +/- 7% (range 36-65%). All patients underwent 48-hour ambulatory ECG monitoring and were randomly assigned to 24 hours without SCS (off period) and 24 hours with SCS (on period). The primary endpoints were: number of ischemic episodes, total duration of ischemic episodes (min), and total ischemic burden (mV*min). RESULTS: The heart rate was not statistically different during the off and on SCS periods (median 64 and 67 b/min respectively). The number of ischemic episodes decreased from a median of 6 (range 0-29) during the off period to 3 (range 0-24) during the on period (p < 0.05). The total duration of ischemic episodes decreased from a median of 29 min (range 0- 186 min) during the off period to 16 min (range 0-123 min) during the on period (p < 0.05). The total ischemic burden decreased from a median of 2.5 mV*min (range 0-19.5 mV*min) during the off period to 0.8 mV*min (range 0-13 mV*min) during the on period (p = NS). The heart rate variability parameters were similar during the on and off periods. CONCLUSIONS: SCS exerts long-term anti-ischemic effects.

Aged↗
PubMed2000

Non-invasive ventilatory approach to treatment of acute respiratory failure in neuromuscular disorders. A comparison with endotracheal intubation.

OBJECTIVE: Prospectively to investigate the efficacy of non-invasive positive pressure ventilation (NPPV) combined with cricothyroid "mini-tracheostomy" (CM) as a first-line intervention in patients with acute respiratory failure (ARF) of neuromuscular origin, in comparison with positive pressure ventilation (PPV) via endotracheal intubation (ETI). DESIGN: Prospective analysis of the short-term outcomes of 14 non-consecutive patients suffering from ARF of neuromuscular origin who were administered NPPV and comparison with the outcomes of 14 matched historical control patients receiving conventional mechanical ventilation (MV) via ETI. SETTING: Adult five-bedded respiratory intensive care unit in a university hospital. PATIENTS AND INTERVENTIONS: Fourteen neuromyopathic patients who developed hypercapnic ARF and were submitted to NPPV (group A) and fourteen matched historical control patients, who were administered PPV via ETI (group B). Seven subjects receiving NPPV also underwent CM. OUTCOME MEASURES: Mortality during ICU stay and treatment failure were evaluated; treatment failure was defined as death or the need for ETI for the NPPV group and as death or the inability to wean from MV for the control group. Length of stay in the ICU and time to improvement, defined as the time required for a significant relief of dyspnea and neurologic impairment and for correction of arterial blood gases, were also compared. RESULTS: Intra-hospital mortality and treatment failure were lower in the NPPV group than in the conventional PPV via ETI group (2 vs 8 cases and 4 vs 11 cases, respectively). In addition, the duration of ICU stay for subjects who underwent NPPV was shorter than for patients who were intubated (13.6 +/- 9.7 vs 47.1 +/- 51.9 days). "Mini-tracheostomy" was well tolerated and no significant side effects were encountered. Two patient were excluded from the study because they showed a severe inability to swallow and needed to be intubated to protect the upper airway from the risk of aspiration. CONCLUSIONS: Non-invasive positive pressure ventilation in combination with CM may be considered as a safer and more effective alternative to ETI in the treatment of patients with neuromuscular disorders (NMD) who develop ARF and require MV; nevertheless, patient selection remains important, since a significant proportion of neuromyopathic patients might have to be excluded from NPPV because of severe risk of aspiration.

Acute Disease↗
PubMed2000

Vasopressin and thirst in patients with posterior pituitary ectopia and hypopituitarism.

OBJECTIVE: Partial diabetes insipidus has been documented in patients with congenital hypopituitarism and posterior pituitary ectopia, some cases being clinically silent except for enuresis. The objective of our study was to evaluate vasopressin (AVP) secretion and thirst appreciation in hypopituitary patients with posterior pituitary ectopia. PATIENTS: Twelve males and three females, aged between 13 and 38 years (median 19 years). Eleven had multiple pituitary deficiencies, adequately replaced at the time of the study, and four were only growth hormone deficient. None of the patients suffered from polyuria, polydipsia or nocturnal enuresis. We tested the patients with a 5% NaCl infusion. Five patients with abnormal vasopressin production were also tested with nitroprusside, which affects baroceptor vasopressin secretion. RESULTS: We found that only two out of 12 patients had normal AVP secretion. Thirst assessment showed severe hypodipsia in one patient, hyperdipsia in three out of 15 and more subtle abnormalities in two out of 15 patients. Concordance was found between osmotically and baroceptor-stimulated vasopressin. CONCLUSIONS: Patients with posterior pituitary ectopia showed a high prevalence of subclinical subnormal vasopressin response to the osmolar stimulus and moreover an impairment of thirst appreciation. Our data on nonosmotically stimulated AVP release suggest the existence of a damage in the hypothalamic vasopressin secreting centres.

Adolescent↗
PubMed2000

Altered bone metabolism in inflammatory bowel disease: there is a difference between Crohn's disease and ulcerative colitis.

OBJECTIVES: The aims of this study were to assess bone metabolism in inflammatory bowel disease (IBD) patients and to evaluate potential differences between Crohn's disease (CD) and ulcerative colitis (UC) with respect to the mechanisms underlying bone loss in this group of diseases. DESIGN AND SETTING: This was a cross-sectional study which started in 1992. Patients were randomly selected for invitation to participate and were examined during the years 1992-95 in one research clinic in Milan. SUBJECTS AND METHODS: Fifty-one patients suffering from CD (30 women and 21 men, mean age 38.7 +/- 13.2 years) and 40 with UC (15 women and 25 men, mean age 34.4. +/- 12.5 years) entered the study. Thirty healthy subjects were selected as sex- and age-matched controls (C). Spine and femoral neck bone mineral density (expressed as T score), calciotropic hormones (parathyroid hormone, PTH; 25-hydroxycholecalciferol, 25(OH)D3; 1,25-hydroxycholecalciferol, 1, 25(OH)D3) and biochemical markers of bone turnover (ostecalcin, OC; total alkaline phosphatase, ALP; type I collagen C-terminal telopeptide, ICTP) were evaluated. RESULTS: Spine and femur T scores were similar in the two groups (spine: CD = -1.49 +/- 1.46; UC = -1. 67 +/- 1.13; femur: CD = -1.80 +/- 1.36; UC = -1.60 +/- 1.03). Based upon the WHO guidelines, only 8% of CD patients and 15% of UC patients had a normal bone mineral density (BMD), 55% (CD) and 67% (UC) were osteopenic, and 37% (CD) and 18% (UC) were osteoporotic. The distribution amongst the three different diagnostic groups was not significantly different between CD and UC groups (P = 0.11). PTH and 25(OH)D3 concentrations were not significantly different between CD and UC patients and controls, whilst 1,25(OH)D3 concentrations were significantly lower in both CD and UC patients compared with controls (P < 0.05). Bone turnover was increased in UC but not in CD patients, as shown by significantly increased concentrations in UC patients of both OC (CD = 7.77 +/- 5.06, UC = 10.03 +/- 6.24, C = 6. 58 +/- 2.87, P < 0.05 vs. C) and ICTP (CD = 5.74 +/- 3.94, UC = 10.2 +/- 8.47, C = 3.48 +/- 0.95, P < 0.05 vs. CD and C). In a stepwise regression that included age, sex, disease duration and cumulative prednisolone dose as independent variables, the femur T score was significantly inversely related to disease duration (r2 = 0.125, F = 6.06) in CD patients. In UC patients, the spine T score was inversely related to age (r2 = 0.107, F = 5.49) and significantly related to sex (more negative in males: r2 = 0.3, F = 16.1); the femur T score was significantly related to sex (more negative in males) and inversely related to the cumulative prednisolone dose (r2 = 0.283, F = 7.3). CONCLUSIONS: These data show that IBD patients have a diffuse osteopenia, the degree of which is not different in CD and UC; however, bone turnover is significantly higher in UC. Finally, osteopenia is related to disease duration in CD, whilst it is related to the male sex and glucocorticoid treatment in UC.

Adult↗
PubMed2000

Intravenous clodronate in the treatment of reflex sympathetic dystrophy syndrome. A randomized, double blind, placebo controlled study.

OBJECTIVE: To evaluate the efficacy of intravenous (i.v.) clodronate in patients with reflex sympathetic dystrophy syndrome (RSDS) and to assess the urinary excretion of type I collagen crosslinked N-telopeptide (NTx) before and after the treatment. METHODS: Thirty-two patients with RSDS were randomized to receive either i.v. clodronate 300 mg daily for 10 consecutive days or placebo. Forty days later, the placebo treated patients received the clodronate treatment. Outcome measures included as a primary endpoint the visual analog scale of pain (VAS, range 0-100); secondary endpoints were a clinical global assessment (CGA, range 0-3) and an efficacy verbal score (EVS, range 0-3). Clinical and biochemical assessments were performed before the treatment, 40 (T40), 90 (T90), and 180 (T180) days later. RESULTS: At T40 the 15 patients randomized to clodronate treatment showed significant decreases of VAS and CGA (p = 0.002, p = 0.001, respectively). Compared with the placebo group (17 patients), significant differences were found in all clinical variables (VAS: p = 0.001; CGA: p = 0.001; EVS: p<0.0001). A further clinical improvement was observed throughout the study. Pooling the results of all 32 patients after clodronate treatment, at T180 the overall percentage decrease of VAS was 93.2+/-15.6%, with 30 patients significantly improved or asymptomatic. Significant inverse correlations between baseline NTx values and decreases of VAS were found at T90 (p = 0.03) and T180 (p = 0.01). No adverse events related to treatment occurred. CONCLUSION: A 10 day i.v. clodronate course is better than placebo and effective in the treatment of RSDS. NTx seems to be a predictive factor for clodronate efficacy.

Adult↗
PubMed1999

High prevalence of hypovitaminosis D among free-living postmenopausal women referred to an osteoporosis outpatient clinic in northern Italy for initial screening.

To establish the prevalence of hypovitaminosis D among free-living postmenopausal women referred to an osteoporosis outpatient clinic in Northern Italy, we evaluated 25-hydroxyvitamin D (25(OH)D) levels in 570 postmenopausal women who had been consecutively referred to our clinic in the 12 months beginning October 1995. Parathyroid hormone (PTH), serum calcium (Ca), creatinine (Cr) and osteocalcin (OC), urinary calcium (Ca24h) and creatinine (Cr24h), and the bone mineral density of the lumbar spine (LBMD) and femur (FBMD) were also measured. 1,25-Dihydroxyvitamin D (1,25(OH)2D) concentrations were measured in 23 women. All women had normal electrolyte serum concentrations and kidney function. Mean +/- SD 25(OH)D concentration was 18.3 +/- 8.3 ng/ml. A significant (p < 0.001) seasonal variation was seen for both 25(OH)D and PTH. Women were divided into two groups based on their vitamin D status: low vitamin D status (25(OH)D < 12 ng/ml, n = 161, 28%) and normal vitamin D status (25(OH)D > or = 12 ng/ml, n = 409, 72%). Hypovitaminosis D was found in 38.5% of all the women in the time period December-May and in 12.5% in the other half-year; among women > 70 years old 51% had hypovitaminosis D in the time period December-May and 17% in the other half-year. PTH was significantly (p < 0.05) increased, and Ca24h, OC and FBMD significantly (p < 0.05) decreased in women with hypovitaminosis D. 1,25(OH)2D positively correlated with 25(OH)D (p < 0.0001), but did not correlate with PTH, age or creatinine clearance. In conclusion, hypovitaminosis D is an important, underestimated problem in Italian free-living postmenopausal women referred to an outpatient osteoporosis clinic.

25-Hydroxyvitamin D 2↗
PubMed1999

Tachycardias in children originating in the right ventricular outflow tract: lack of clinical features predicting the presence and severity of the histopathological substrate.

The aim was to determine whether the clinical features of tachycardias originating from the right ventricular outflow tract in children with an apparently normal heart could predict the presence and the severity of the histopathological substrate. Thirteen children (median age 6 years; range 6 months-12 years) with tachycardia originating from the right ventricular outflow tract of apparently normal hearts, were assessed by echocardiography, heart catheterization with angiography, endomyocardial biopsy (13 patients) and magnetic resonance imaging (MRI) (nine patients). Tachycardia was symptomatic in six and sustained in nine. Endomyocardial biopsy and MRI revealed acute myocarditis in five patients (38%), fatty infiltration of the right ventricle in two (15%), and minor histologic abnormalities in three (23%). Myocarditis was diagnosed in three of nine patients with sustained ventricular tachycardia, as opposed to two of four with non-sustained tachycardia (p = NS); in three of six symptomatic versus two of seven asymptomatic patients (p = NS); and in two of eight patients in whom ventricular tachycardia was induced during exercise testing as opposed to one of three in which it was not inducible (p = NS). A histopathological substrate was found in six of nine patients with sustained ventricular tachycardia, and in all four with non-sustained tachycardia (p = NS); in five of six patients with symptoms versus five of seven asymptomatic patients (p = NS); and in five of eight with inducible ventricular tachycardia during exercise testing versus all three in whom it was not inducible (p = NS). The mean rate of tachycardia was 184+/-39 beats min(-1) in patients with myocarditis, as opposed to 171+/-48 in patients without myocarditis (p = NS); and 163+/-33 in patients with a histopathological substrate compared with 210+/-65 in patients without a histopathological substrate (p = NS). It is concluded that a histopathological substrate is present in the greater majority of children affected by the so-called right ventricular outflow tract tachycardia, but that the clinical features of the tachycardia do not predict the presence and the severity of this histopathological substrate.

Biopsy↗