In 36 children without shunts nearly 280 electrical impedance measurements were carried out in order to estimate the accuracy of the impedance cardiography as a means of calculating output. During evaluation up to 22 combinations of test conditions and possibilities of evaluation per child were tested. As a reference method the Fick Principle was used. The reproducibility of impedance measurements showed itself to be high, but no agreement of the results by impedance cardigraphy and corresponding values by the Fick method could be found. Some reasons give rise to suppose that impedance cardiography only reflects changes in the intrathoracic fluid level occurring during heart action from which because of formal reasons no interference should be drawn about the original cardiac output. Besides physical arguments tell against the possibility of picking up these volume-changes quantitatively by analyzing transthoracic electrical impedance.

Adolescent↗

PubMedDate not supplied

Reduced left ventricular size and endocardial fibroelastosis as correlates of mortality in newborns and young infants with severe aortic valve stenosis.

30 patients with severe aortic valve stenosis presented in severe congestive heart failure within the first 2 months of life. In 25 of them, left ventricular volume and contractility were assessed; five of them had a left ventricle of normal size, in 11 left ventricular size was diminished, and in nine patients it was enlarged. Eleven of the infants had extensive endocardial fibroelastosis (EFE) evidenced angiographically by myocardial sinusoids in ten of them and established at autopsy in six. The presence of EFE correlated with the size of the left ventricle; eight of 11 with a small left ventricle, two of five with a normal-sized left ventricle, and one of nine with an enlarged left ventricle displayed EFE. The severe depression of left ventricular function associated with EFE was documented by left ventricular volume determinations on exclusion of the myocardial sinusoids. Of 30 patients, 12 (including eight of 26 who underwent surgery) did not survive. Mortality, severity, and early onset of symptoms were associated mainly with small size of the left ventricle and with the severe left ventricular dysfunction associated with EFE.

Aortic Valve Stenosis↗

PubMedDate not supplied

Transcatheter closure of atrial septal defects by the "buttoned" device: complications and need for surgical revision.

Immediate and medium-term experience with transcatheter closure of a secundum atrial septal defect by the "buttoned" device in seven patients is reported. Complications occurred in two patients during the procedure. In one patient with complications, the occluder was partly released in the right atrium. All efforts to correct its position were unsuccessful and caused considerable deformation of the device, which had to be removed surgically. In the other patient with complications, disconnection of the occluder and counteroccluder occurred immediately after removal of the loading wire. Both parts were retrieved by catheter. Five patients had uneventful closure of the atrial septal defect. On follow-up, however, displacement of the device towards the mitral valve was observed in two patients, which caused mitral regurgitation. Surgical removal of the device and repair of the mitral valve was necessary in both patients. Two years after the procedure, the atrial septal defect was closed completely in two of the remaining three patients and a small residual defect persisted in one patient.

Adolescent↗

PubMedDate not supplied

Velocity of oxygen uptake response at the onset of exercise: A comparison between children after cardiac surgery and healthy boys.

A comparison was carried out concerning maximal oxygen uptake, oxygen uptake adjustment at the onset of high-intensity exercise, and maximal blood lactate between 10 healthy prepubertal boys and 35 children after repair of cardiac malformations or after Fontan operation. Mean maximal oxygen uptake (VO2) was moderately reduced in children after repair of tetralogy of Fallot or after Mustard or Senning operations and severely reduced after Fontan operations. Conversely, mean half-time of VO2 response was moderately prolonged in children after repair of tetralogy of Fallot or after Senning and Mustard operations and considerably prolonged after Fontan operations. According to our results unfavorable kinetics of VO2 response to physical exercise are present in addition to reduced aerobic power in many of the operated children. Besides being less qualified for endurance performance, these children are also less prepared for short, high-intensity exercise.

Cardiac Surgical Procedures↗