Monika Rutkowski

Preclinical abnormal segmental cardiac manifestations of thalassemia major in children on transfusion-chelation therapy: Echographic alterations of left ventricular posterior wall contraction and relaxation patterns

The purpose of this study was to evaluate young asymptomatic patients with thalassemia major by utilizing an echocardiographic technique which traces an expanded image of the left ventricular posterior wall (LVPW). This technique separates global cardiac function from segmental changes in LV free wall thickness during systole and diastole. The study population consisted of 13 patients aged 2 to 15 years with classical homozygous beta-thalassemia. Thirty-one normal healthy individuals age 4 to 13 years served as controls. Echocardiograms, height, weight, and blood pressure were measured in all patients at their lowest hemoglobin level. Traces of the expanded LVPW were analyzed and measured; while total net thickening relative to baseline was similar in both groups at all times during systole and diastole, the LVPW in children with thalassemia was statistically thinner than in controls (p less than 0.001). Contraction was a nearly linear process in controls, but for patients with thalassemia, it was significantly faster at 50% and 75% of systolic time (p less than 0.05). Relaxation, on the other hand, was not linear for either controls or thalassemic patients. In both groups, diastolic thinning was biphasic; however, LV walls of thalassemic children thinned more slowly than normal for each time point in diastole (p less than 0.001). These results demonstrate that young children with thalassemia major, even if kept at strict transfusion and chelation regimens, have defects in LV segmental wall motion which antedate the appearance of clinical symptoms.

Abnormalities of the corrected QT interval in familial dysautonomia: An indicator of autonomic dysfunction

We report abnormalities in corrected QT intervals with changes in position and after exercise in patients with familial dysautonomia and confirm the previously reported finding of abnormal heart rate and blood pressure responses. Prolonged corrected QT intervals (> 440 msec) with lack of appropriate shortening with exercise is a noninvasive means of demonstrating an aberration in autonomic regulation of cardiac conduction.

Electrocardiographic Measures and Heart Rate Variability in Patients with Familial Dysautonomia

Cardiovascular abnormalities are prominent in the genetic disorder, familial dysautonomia (FD). To determine if autonomic dysfunction involves cardiac, as well as peripheral vascular integrity, noninvasive tests were performed in 10 FD patients and 8 healthy control subjects while supine and at 90 degrees tilt. Simultaneous blood pressure (BP) and heart rate (HR) and QTc were obtained, while performing signal-averaged electrocardiography (SAECG) and heart rate variability (HRV). FD subjects were tested on 2 separate days, before and 1 h after oral fludrocortisone or midodrine; controls were tested once without medication. With tilt, all FD subjects decreased mean BP > or = 24 mm Hg by 5 min. On SAECG, 70% of supine FD subjects had a prolonged tQRS; only 2 FD subjects shortened tQRS with tilt. The QTc interval was prolonged (> 440 ms) in 2 supine FD subjects; with tilt, the QTc prolonged in a third. Frequency domain analysis of HRV revealed that mid (MF) and high frequency band areas were significantly decreased when supine, but not when upright. On time domain analysis, the pNN50 was significantly decreased in FD subjects (8.9 +/- 1.7 vs. 17.7 +/- 3.6%, p < 0.01). Fludrocortisone lowered supine BP and HR and increased supine MF area. Midodrine raised supine and erect BP, lowered erect HR, and shortened erect QTc. Although all FD subjects have abnormal orthostatic BP and HR responses, cardiac tone, as assessed by electrocardiographic and HRV responses, varies. Prolongation of the tQRS appears to be a sensitive but not specific indicator of autonomic dysfunction. QTc prolongation may indicate more extensive sympathetic dysfunction. HRV data suggest some FD patients have abnormalities in parasympathetic, as well as sympathetic, cardiac tone.

Pacemakers in patients with familial dysautonomia--a review of experience with 20 patients.

Familial dysautonomia (FD) is a genetic disease associated with a high incidence of sudden death. If fatal bradyarrhythmia is an etiological factor then the incidence of sudden death should decrease after pacemaker placement. Retrospective review of 596 registered FD patients revealed that 22 FD patients (3.7%) had pacemakers placed between December 1984 and June 2003. Clinical and electrocardiographic indications for placement and demographic data were assessed for 20 of the 22 patients (10 males, 10 females, ages 4 to 48 years). Two patients were excluded because of insufficient data. Prior to pacemaker placement, presenting symptoms were syncope and cardiac arrest, 16/20 (80%) and 6/20 (30 %), respectively. Asystole was the most frequent electrocardiographic finding and was documented in 17/20 patients (85 %). Other electrocardiographic abnormalities included bradycardia, AV block, prolonged QTc and prolonged JTc. The average duration of pacemaker utilization was 5.7 years (range 5 months to 14.5 years). Complications included infection (1 patient) and wire migration (2 patients). In the one patient with infection, the pacemaker was permanently removed. This patient then experienced multiple syncopal episodes and death. There were 7 other deaths. Three deaths occurred suddenly without preceding events, and 4 patients had non-cardiac causes of death. None of these 7 deceased patients had recurrence of syncope after pacemaker placement. In the 12 surviving patients, 6 had recurrence of syncope but none had cardiac arrest. Pacemaker placement may protect FD patients from fatal bradyarrhythmia and may decrease the incidence of syncope. However, data are limited and prospective analysis is needed.

Left ventricular volume after correction of isolated aortic coarctation in neonates

To determine the capacity of the left ventricle to expand after biventricular repair of left ventricular (LV) outflow tract obstruction, we studied pre- and postoperative echocardiographic variables from 14 infants (< 2 months old) who underwent successful repair of isolated aortic coarctation. We show that in this lesion, LV volume is a dynamic entity, and that the left ventricle achieves a larger cavity size once surgery relieves compression and normalizes loading conditions.

Sinus Venosus Atrial Septal Defect Associated with Vein of Galen Malformations: Report of Two Cases

SummaryTwo unique cases are presented of infants with signs of vein of Galen malformations, whose unsuspected associated sinus venosus atrial septal defects were detected during routine echocardiography. A conservative approach to cardiac treatment is advocated.

Repair of posterior left ventricular aneurysm in a six-year-old boy.

Left ventricular aneurysms and diverticula are rarely encountered in the pediatric age group. This paper reports a case of congestive heart failure and mitral regurgitation in a 6-year-old boy with a large posterolateral left ventricular aneurysm. Complete repair was successfully performed by excision of the aneurysm and Dacron patch reconstruction of the left ventricular free wall. The patch extended onto the posterior annulus of the mitral valve, thus restoring the mitral valve to normal geometry and correcting the mitral insufficiency. The surgical literature on congenital cardiac diverticula and acquired aneurysms in children is reviewed and summarized.

Congenital fistulous tract between aorta and right atrium presenting as heart failure in a newborn

SummaryA newborn with a fistulous communication between the right coronary sinus and right atrium had congestive heart failure on the first day of life. Medical management was unsuccessful and operative repair was performed using bypass surgery at 5 days of age. Echocardiographic evaluation preoperatively diagnosed the defect correctly and postoperatively confirmed a complete repair. Since aneurysms and/or fistulae can occur in other sinuses after an initial repair of the presenting lesion, the infant will continue to be followed with periodic echocardiographic and clinical evaluations.

Magnetic resonance imaging of cor triatriatum.

SummaryMagnetic resonance imaging utilizing spin echo sequences was used to demonstrate cor triatriatum in an 18-year-old boy. Phase map images aided the diagnosis by demonstrating the presence of slowly flowing blood in the accessory atrial chamber. Magnetic resonance is an excellent modality for the noninvasive diagnosis of cor triatriatum.

Pediatric echocardiography: applications and limitations.

Echocardiography is an extraordinarily useful imaging technique in fetuses, infants, children, and adolescents. Recent technologic innovations have expanded its versatility in the pediatric population. However, limited societal resources, limitations inherent to ultrasound imaging, and numerous imaging options even within the field of pediatric echocardiography necessitate the discriminate and thoughtful use of echocardiography in children. The clinical assessment remains a critical prelude to echocardiographic examination of the pediatric cardiovascular system.