Vincenzo Colloridi

Human Parvovirus B19 Infection in Infancy Associated with Acute and Chronic Lymphocytic Myocarditis and High Cytokine Levels: Report of 3 Cases and Review

Human parvovirus B19 infection is occasionally associated with acute lymphocytic myocarditis (ALM). Three infants with B19 virus-associated ALM were followed up clinically, histologically, and immunovirologically. Each infant had B19 virus DNA in the blood or B19 virus-specific IgM antibodies. Two infants with postnatal infection recovered after immunosuppressive therapy. The third infant with possible prenatal infection developed chronic persistent myocarditis associated with persistent B19 virus DNA in the blood. All 3 infants had increased levels of interferon-gamma, tumor necrosis factor-alpha, and interleukins -6 and -8. Four newborns with congenital B19 virus infection and 4 infants and children who had postnatally acquired B19 virus infection without myocarditis all had normal levels of these cytokines. These observations suggest that B19 virus infection in infancy causes ALM in some infants and children.

Myocardial Scintigraphy with 99mTc-Sestamibi in Children with Kawasaki Disease

Kawasaki disease (KD) is a systemic vasculitis syndrome of early childhood. It involves particularly the coronary arteries and may cause aneurysms and thrombotic occlusions. Echocardiography is the most useful method of detecting coronary aneurysms. Nevertheless, obstructive lesions are difficult to evaluate and often need invasive coronary angiography. An important feature of this disease is the possibility of finding coronary pathology several years after the onset. This characteristic makes KD an important cause of coronary artery disease (CAD) in young adults. Thus patients with KD and previously diseased coronary arteries should be kept under long-term control. However, coronary angiography is invasive and cannot be performed repeatedly, espe cially in young patients. As an alternative, thallium 201 scintigraphy has been employed, but its low-energy photons are suboptimal for standard gamma-camera imaging, particularly in children aged less than three years. To verify the usefulness of a noninvasive assessment of myocardial perfusion, the authors used rest and dipyridamole 99mTc-Sestamibi scan in 15 children (ranging from one to six years of age) with Kawasakis cardiac involvement. Coronary aneurysms have been demonstrated by echocardiography in 12 patients; 8 patients were also submitted to cardiac catheterization. The sensitivity of 99mTc-Sestamibi imaging for detection of overall coronary lesions was 88% and the specificity was 93%. These data suggest that rest/dipyridamole 99mTc-Sestamibi scintigraphy is an accurate and noninvasive method for the detection and follow-up of Kawasakis cardiac damage even in patients aged one year.

Radioisotope assessment of heart damage in hypertransfused thalassaemic patients

Twenty-five thalassaemic patients treated with repeated blood transfusion (BT) and intensive iron removal therapy were studied by echocardiography and rest/stress equilibrium gated radionuclide angiocardiography (EGNA). Stress left ventricular ejection fraction (LVEF) showed an important negative correlation with number of BTs (r = −0.75). Abnormal values of stress LVEF were measured after 200 BTs: these data demonstrate the effectiveness of stress LVEF in the follow-up of patients who have undergone repeated BTs and the clinical importance of intensive chelation therapy. Peak filling rate did not show diagnostic value in the early detection of iron cardiotoxicity. However, its inverse correlation with BT (r = −60) indicates that iron overload depresses the diastolic parameters.

Ventricular Thrombosis During Permanent Endocardial Pacing in a Pediatric Patient with Hemorrheological Disorders

Thrombosis in the right atrium or ventricle is a rare compli cation of permanent endocardial pacing in adults. To the best of our knowledge, this complication has not been previously reported at all in the pediatric age group. We report on a case of a 7‐year‐oId boy who had large left ventricular thrombi that occurred during permanent endocardial electrical stimulation. Subsequent pulmonary emboli complicated congestive heart failure in this patient. As a diagnostic approach, echocardiography and pulmonary perfusion scintigraphy were used. We comment on possible causes of this serious complication and suggest hemorrheological and platelet activation studies in patients with permanent endocardial pacing.

Holoprosencephalic disorders. Case report of a semilobar type.

A child with microcephaly, facial dysmorphisms, seizures, and congenital car diopathy is presented. On the basis of skull x-rays, electroencephalogram, trans- illumination of the head, and computed tomography (CT) scan, the diagnosis of semilobar holoprosencephaly was made. The heterogeneous etiology of the disorder is discussed in order to evaluate the recurrence risk. The usefulness of CT scan for the classification in the different types of holoprosencephaly is stressed.

Peculiarities of Prevalence and Morphology of Congenital Heart Disease Detected In Utero

Intrauterine echocardiography is changing our knowledge of congenital heart disease; cardiac defects diagnosed in utero have distinctive features of both prevalence and morphology when compared with those observed just after birth. We reviewed a series of 171 fetal heart conditions: 148 were diagnosed at intrauterine echocardiography, the diagnosis being verified at autopsy in 41, and 23 were observed at the postmortem only. Peculiarities of prevalence consisted in an excess of various defects, such as hypoplastic left heart syndrome, atrial isomerism, pulmonary atresia, and atrioventricular and atrial septal defects, and in a reduced number of completely different conditions, such as transposition of great arteries and aortic coarctation. Differences in prevalence have been attributed to difficulties in diagnosing some particular anomalies in utero, to the selection of pregnancies undergoing screening, and to the special intrauterine evidence of some heart defects. Peculiarities in morphology result from the coexistence with extracardiac malformations, from the changes in shape conditioned by fetal hemodynamics, and from the intrauterine evolution of the morphology of some malformations. We concluded that the knowledge of these characteristic traits was helpful to cardiac pathologists, pediatric cardiologists, and obstetricians, and allowed the re-evaluation of the role of hemodynamic factors in remodeling the malformed cardiovascular appara-tus.

Transesophageal electropharmacologic test in a newborn with familial Wolff-Parkinson-White syndrome.

SummaryA newborn infant with familial Wolff-Parksinson-White (WPW) syndrome presented with a supraventricular tachycardia of 300 beats/min, refractory to digoxin and flecainide administration. Serial electropharmacologic tests were performed via the esophagus before and during oral therapy with verapamil at 40, 80, and 60 mg daily. Before treatment, tachycardia could be induced with programmed stimulation. A regimen of verapamil at 60 mg daily, which resulted in the initiation of nonsustained (<10 s) reciprocating tachycardia only, without clinical recurrences, was identified as suitable long-term oral therapy. The efficacy of this drug regimen in preventing episodes of tachycardia was confirmed during a 1-month follow-up period. It is concluded that transesophageal atrial pacing is a useful, noninvasive means of selecting treatment in neonates with supraventricular tachycardia, when nonconventional drugs are considered for prophylaxis.

Permanent Mechanical Catheter Ablation of an Accessory Pathway in a Child

Permanent mechanical ablation of an accessory atrioventricular pathway was observed in an infant during intracavitary electrophysiological mapping. The persistent lack of preexcitation was confirmed during a 15‐month follow‐up period.

ERYTHROCYTE DEFORMABILITY AND PLATELET FUNCTION IN CHILDREN WITH CYANOTIC CONGENITAL HEART DISEASES

Children with erythrocytosis due to cyanotic congenital heart diseases (CCHD) show an increased tendency to thrombotic disorders. We studied red cell deformability and 2,3-DPG concentration, platelet aggregation and platelet release in 18 children with CCHD ( PaO2 <70 mm Hg). Erythrocytosis (Ht>55%) was present in 3 patients. Red cell deformability was measured by a filtration technique. Platelet aggregation was assessed by the change in light transmission of platelet-rich plasma after addition of ADP (1-3 μM). Plasma β-TG level was determined by a radioimmunoassay, and 2,3-DPG by enzymatic analysis. Filtration time was 80±10 sec/ml (mean±SD) vs 30±8 sec/ml (p<0.01). 2,3-DPG was not significantly increased: 4.83±0.15 mmol/l erythrocytes (mean±SD) vs 4.18±0.1. In all samples platelet aggregation was impaired, while plasma β-TG was increased: 55±5μg/ml (mean±SD) vs 20±2, p<0.001. No correlation was demonstrated between red cell deformability and erythrocytosis or 2,3-DPG content. Our data show that rigid red cells and “exhausted” platelets (as suggested by impaired in vitro aggregation and increased plasma β-TG level) may occur in patients with CCHD also in absence of severe hypoxia.