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Biomedical subjects

B Friedli

Publications and source records attributed to B Friedli.

At least 91 records · Page 5Linked to original sources
PubMed1986

Ventricular arrhythmias in children and adolescents.

The spectrum of ventricular arrhythmias, as observed in adolescents and children, is reviewed. The significance and prognosis of such rhythm disturbances depend to a great extent on the clinical setting in which they occur. Ventricular premature beats (VPBs) are found in a significant percentage of normal adolescents, though usually in very small numbers over 24 h. Frequent unifocal VPBs, even in bigeminy, may occasionally be observed. They are considered benign in the absence of heart disease, especially when they disappear during exercise. Ventricular tachycardia (VT) appears as a complication of some heart lesion in a majority of cases. This may be cardiomyopathy, mitral valve prolapse, sometimes congenital heart defects or occasionally rare anomalies such as long Q-T syndrome, tumors, or right ventricular dysplasia. Idiopathic (primary) VT also occurs in the young, its overall prognosis is more favorable compared to VT with heart disease. The problem of ventricular arrhythmias late after open heart surgery deserves special comment, as it seems to be connected with late sudden death. The investigation and treatment of ventricular arrhythmias in children and adolescents is discussed. The decision on who should be treated is easy in the presence of symptoms, but difficult and controversial in asymptomatic youngsters.

Adolescent↗
PubMed1985

[Use of Doppler ultrasound in cardiac diagnosis].

In cardiac diagnosis Doppler ultrasound provides quantitative data in the assessment of pressure gradient and valve area in stenotic lesions. In atrioventricular valves pressure half-time can be determined. In regurgitant lesions the only method capable of providing quantitative analysis of aortic regurgitation is calculation of forward-to-reverse flow ratio by multigate Doppler. All the other single-gate Doppler or 2-D-echo Doppler methods, such as LV or LA mapping, recording of impaired mitral flow and diastolic/systolic flow ratio, permit only semiquantitative assessment of regurgitant volumes. Finally, semiquantitative analysis of shunt volumes appears possible in children.

Child↗
PubMed1985

Intraventricular conduction disturbances after correction of tetralogy of Fallot: can bifascicular and trifascicular block be diagnosed from the surface ECG?

To determine the origin of conduction disturbances commonly seen in the ECG after correction of Fallot's tetralogy, 36 children underwent electrophysiologic studies; these included endocardial recordings of right ventricular (RV) and left ventricular (LV) apical activation and His-bundle recordings. The surface ECG showed a pattern of complete right bundle branch block (RBBB) in 22, and RBBB with left-axis deviation (LAD)--so-called bifascicular block--in nine; the remaining five had RBBB, LAD, and a long PR interval, often considered as indicating trifascicular block. Eight of 22 patients with RBBB and normal axis had delayed RV apical activation (36%), indicating a proximal lesion. Of nine patients with RBBB and LAD, four only had delayed RV apical activation (44%); in the other five, therefore, the RBBB pattern was due to a peripheral lesion (ventriculotomy); they cannot be considered as having true bifascicular block. LV activation was not delayed in any case. In five cases, the surface ECG suggested trifascicular block (long PR in the presence of RBBB and LAD). His-bundle recordings showed the HV interval to be prolonged in only two cases, at the upper limit of normal in two, and short in one. The AH interval was prolonged in all and was mainly responsible for the long PR interval. Thus, the surface ECG is not a reliable tool for making a diagnosis of true bifascicular block and trifascicular damage after correction of Fallot's tetralogy. This may explain controversies existing about the prognosis of such conduction abnormalities.

Adolescent↗
PubMed1985

[Pulsed Doppler and bidimensional echocardiography in patent ductus arteriosus].

The classical form of patent ductus arteriosus (PDA) does not usually pose any difficulty in diagnosing. When the auscultatory signs are atypical, for example in the newborn or in cases with pulmonary hypertension, pulsed Doppler echocardiography may be a useful diagnostic aid. This study reports the results of pulsed Doppler examination in PDA. Twenty-four children with a suspected PDA underwent pulsed Doppler examination during 2D echocardiography. This population was divided into 2 groups; Group I: children who underwent catheterisation, and group II: in which catheterisation was not performed. The mean age in Group I was 7 years compared to 50 days in Group II, which mainly comprised newborn and premature babies. Direct visualisation of PDA by 2D echo was attempted in all cases. The search for a PDA by pulsed Doppler was made by positioning the sample volume at the bifurcation of the main pulmonary artery. PDA is associated with turbulent systolo-diastolic flow away from the transducer. Suprasternal and subcostal views were also used. In Group I (13 cases) PDA was directly visualised by 2D echo in 7 children (53 p. 100). By comparison, pulsed Doppler examination diagnosed all 13 cases of PDA; these results were confirmed at catheterisation or surgery. In Group II (11 cases) direct visualisation of PDA was successful in 6 cases (54 p. 100). Pulsed Doppler was non-specific, showing typical flow disturbances in 8 cases and systolic turbulence in 3 cases at the level of bifurcation.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1985

[Outcome of patients operated on for aortic coarctation during the 1st year of life].

A coarctectomy performed on infants with congestive heart failure in the first year of life is an emergency procedure due to the "coarctation syndrome". An intracardiac anomaly is also present in the majority of cases. The surgical risk of coarctectomy in the newborn infant or during the first year of life is now low (7 percent in our study), but intermediate-term mortality rates were relatively significant (24 percent in our study), due to intracardiac anomalies and their surgical correction. Without treatment, however, the coarctation syndrome proves fatal in two out of three cases before one year of age. The principal long-term complication is recurrence of the coarctation resulting from the absence of growth at the anastomosis. It occurs in 20 to 50 percent of cases depending on the study, the diagnostic criteria, and length of time since the surgery. This complication is more frequent when the coarctectomy was performed in the first month of life. Another coarctectomy must be undertaken in these cases. Persistent arterial hypertension without recurring coarctation is rarely observed, but is frequently encountered following a coarctectomy in an older child or adult. It should be noted that the systolic arterial blood pressure in almost all infants in our study was between the 50th and 97th percentile for normal children of this age. Aside from the problem of recurring coarctation, the long-term follow-up depends principally on associated valvular lesions, particularly aortic (bicuspid valves are very frequent) and mitral valvular lesions. Even though surgery has greatly improved the prognosis of coarctation in children, these infants must have long-term postoperative surveillance.

Aortic Coarctation↗
PubMed1984

Sinus node function and conduction system before and after surgery for secundum atrial septal defect: an electrophysiologic study.

Arrhythmias are common in the natural history as well as in the late postoperative course of patients with atrial septal defect (ASD); electrophysiologic disturbances may result from the ASD itself or from surgery. Electrophysiologic studies were performed in 18 children (mean age 10 years) both before and after surgical closure of the ASD. Sinus node (SN) function, conduction intervals and refractory periods (atrial and atrioventricular [AV] nodal) were determined. Before surgery, corrected SN recovery time was prolonged in 14 patients; the mean value for the group was 357 +/- 163 ms. The AH interval was slightly prolonged, as were AV nodal refractory periods. Postoperatively, SN recovery time decreased in all patients who remained in sinus rhythm (p less than 0.02), but 5 patients had atrial ectopic rhythm. The AH interval decreased significantly (p less than 0.02), as did the refractory periods, mainly for the AV node (p less than 0.01). The pacing rate at which second-degree AV block occurred increased. Thus, closure of ASD improves AV conduction, decreases AV nodal refractory periods and improves SN function, probably by suppressing rightsided heart volume overload. However, SN function may be lost, probably as a result of the operative procedure.

Adolescent↗
PubMed1984

[Hypertrophic cardiomyopathy. Apropos of 3 cases].

Three cases of hypertrophic cardiomyopathy are described. The first case, a man aged 17 years, died suddenly, while the second case was diagnosed in a 40-year-old male who presented with auricular fibrillation; this patient died two years later from a cerebral tumour. The third patient, who died at the age of 72 years from cerebral haemorrhage, had had a pacemaker inserted five years previously because of atrioventricular block. The cardiomyopathy was diagnosed only at autopsy. The morphological features of the heart in these cases are documented. The characteristic histological aspect of the myocardial fibres, commonly referred to as disarray, is described and our findings are compared with those in the literature. The relationship between the various morphological presentations and their clinical manifestations is discussed.

Adolescent↗
PubMed1984

Cross sectional echocardiographic assessment of left ventricular volume and ejection fraction in patients with tetralogy of Fallot. Comparison with biplane angiographic measurements.

To evaluate the usefulness and accuracy of calculating left ventricular volume and ejection fraction from cross sectional echocardiograms in patients with tetralogy of Fallot, 28 patients were studied within 24 hours of cineangiography. Indexed end diastolic and end systolic volumes were calculated from three different paired echocardiographic projections: (a) the two and four chamber views from the apical impulse window, (b) the parasternal long axis view and the subxiphoid long axis view, and (c) the four chamber view and short axis precordial views at mitral and papillary muscle level. Volumes were calculated in five different ways using three different algorithms (area length, Simpson's rule, the Parisi formula). The results were compared with data obtained from biplane angiograms using Graham's formula. The correlation varied with the algorithm used: the best results were obtained with the area length method using the parasternal long axis view and the sub-xiphoid view. The correlation was less accurate for the ejection fraction. The second best correlation was obtained with the area length method using the two and four chamber apical views; the other correlations were less satisfactory. Thus these results show that left ventricular volumes can be accurately assessed by cross sectional echocardiography in children with tetralogy of Fallot and that the ejection fraction can be satisfactorily estimated. The results depend on careful gain setting and precise demonstration of the left ventricular endocardium, which is best seen in the sub-xiphoid and long axis views.

Adolescent↗
PubMed1984

Factors affecting left ventricular function after correction of tetralogy of Fallot.

To investigate the possible causes of left ventricular dysfunction after total correction of tetralogy of Fallot, 84 patients, aged 1 1/2 to 16 years, were studied by left ventricular cineangiography both before and a mean of 4.6 months after operation. Left ventricular ejection fraction and mean velocity of circumferential fibre shortening were calculated; using multivariate analysis the results were correlated with age at operation, the degree of hypoxia and polycythaemia before operation, occurrence of hypoxic spells, and the duration of operative procedures (cardiopulmonary bypass and aortic cross clamping). The postoperative left ventricular ejection fraction was decreased slightly or moderately in 46% of patients. The variable most significantly associated with altered left ventricular function was a history of hypoxic spells. Age, the degree of chronic hypoxia, and polycythaemia did not correlate significantly with left ventricular function indices. Although no correlation was found between the duration of cardiopulmonary bypass and left ventricular ejection fraction, bypass times exceeding 120 minutes were associated with decreased ejection fractions; this was statistically significant and independent of the variable "hypoxic spells". Thus repeated episodes of acute hypoxia and long operative procedures appear to have a deleterious effect on left ventricular function in tetralogy of Fallot.

Adolescent↗
PubMed1984

Intrathoracic neuroblastoma presenting with neonatal cardiorespiratory distress.

We report an unusual presentation of congenital intrathoracic neuroblastoma. Severe respiratory distress was present at birth and several salient clinical signs were suggestive of neonatal myocarditis. Excessive catecholamine secretions may have caused the observed cardiac dysfunction. Peculiar previously unreported cutaneous lesions were also noted in this case.

Electrocardiography↗
PubMed1984

[Doppler pulse and interventricular communication].

To test the diagnostic accuracy of pulsed Doppler and two-dimensional echocardiography (2D-echo) in ventricular septal defect (VSD), 32 children were studied. All were suspected on clinical grounds to have a VSD. In 17 children, the VSD was proven by cardiac catheterization (group I, mean age 10 years); in 15, only non-invasive investigation was carried out (group II, mean age 1 year). In group I, 2D-echo showed a ventricular septal defect in 14 cases (82%); the Doppler study demonstrated a typical systolic turbulent flow in the right ventricle, in front of the septum, in all cases. In group II, the VSD was visualized by 2D-echo in 11 cases (73%). Pulsed Doppler showed a typical turbulent flow in the right ventricle in all cases. Thus, pulsed Doppler appears more sensitive in detecting ventricular septal defect--especially of small size--than 2D-echo. The diagnostic value of Doppler remains intact when associated cardiac malformations are present and in cases of pulmonary hypertension, as long as the shunt is not reversed.

Adolescent↗
PubMed1984

[Coarctation syndrome in infancy and its outcome: surgical results and long-term follow-up].

Between 1972 and 1983, 29 newborns and infants were treated surgically for coarctation of the aorta. The mean age at operation was 2 months 7 days. 76% of the patients (22/29) had an associated intracardiac malformation, 8 requiring correction. The early mortality rate (due to coarctation repair) was 7% (2/29). The total mortality rate was 31% (7/29). Four of the 7 late deaths occurred during surgical correction of an intracardiac malformation. Twenty children were followed up for 1 to 10 years (mean 4 1/2 years) after surgery. Four patients (20%) had a recoarctation. All 4 recurrences occurred within 2 years after surgery, and in patients operated on during the first month of life. Blood pressure at the latest outpatient visit was above the 97th percentile in 6 children, 4 of whom had recoarctation. Among the patients with no evidence of recurrence, 86% had a blood pressure between the 50th and the 97th percentile or just above the 97th. Five patients underwent a maximal exercise test: none developed excessive elevation of systolic blood pressure, and no pressure difference appeared between arm and leg during the exercise test in those who had none at rest. Thus, early surgical correction improves the prognosis of infantile coarctation syndrome, but recoarctation may occur; long term follow-up is advisable.

Age Factors↗
PubMed1984

Hemodynamic effect of isoprenaline and dobutamine immediately after correction of tetralogy of Fallot. Relative importance of inotropic and chronotropic action in supporting cardiac output.

In order to compare the effect of isoprenaline and dobutamine immediately after correction of tetralogy of Fallot, 12 randomly selected patients were studied postoperatively. Left ventricular end-diastolic volume, measured preoperatively by means of left ventricular angiograms in eight patients, was decreased to a mean value of 58.6 +/- 5.5 ml/m2 (mean +/- standard error of the mean). Postoperatively, cardiac output was measured by thermodilution before, during, and after infusion of increasing doses of isoprenaline (0.05, 0.1, and 0.2 micrograms/kg/min) and dobutamine (2.5, 5, and 10 micrograms/kg/min) successively given in each patient. Simultaneously, central venous, left atrial, pulmonary arterial, and systemic arterial pressures were recorded. Cardiac index increased significantly in response to all three doses of isoprenaline. Dobutamine produced only a small increase which was not statistically significant. Stroke volume index did not vary significantly with either drug. Consequently, cardiac index was directly related to heart rate. Preload of the left ventricle as well as afterload was significantly reduced (p less than 0.01 and p less than 0.05, respectively) by isoprenaline but not by dobutamine. An increase in left ventricular work index per minute was found with both drugs; however, only with isoprenaline was the increased work accompanied by a significant increase in cardiac index. We conclude that patients with tetralogy of Fallot usually have a small left ventricle which, immediately after correction, reacts to catecholamines by only an insignificant increase in stroke volume index. Consequently, isoprenaline is more effective than dobutamine in raising cardiac index due to the increase in heart rate. Moreover, it decreases systemic vascular resistances and obviates the need for administration of a vasodilator.

Adolescent↗
PubMed1983

[Long-term evolution of children operated on for tetralogy of Fallot].

While open heart surgery has much improved the prognosis of tetralogy of Fallot, surgical repair does not usually restore completely normal anatomy. Residual defects include some degree of pulmonary stenosis, pulmonary regurgitation (unavoidable if the pulmonic valve and valve ring need to be widened by patch), and, sometimes, residual ventricular septal defect. In addition, left and right ventricular dysfunction of mild to moderate degree, unrelated to residual lesions, may be observed. Other late complications may arise from conduction disturbances and ventricular arrhythmias. The occurrence of late sudden death is related to such rhythm disturbances, it occurs particularly in patients with ventricular premature beats on routine ECGs and is probably due to ventricular fibrillation. Patients with such premature beats must therefore be treated with antiarrhythmic drugs. In spite of these late complications, the majority of patients lead a normal life and professional integration is usually excellent. Many patients practise sports. Exercise tests late after surgery show mild or moderate decrease in maximal exercise performance if there are residual lesions of significance, and especially when there is more than one such residua (e.g. pulmonic stenosis and regurgitation). Life expectancy should be normal, at least for postoperative patients with minimal residual lesions.

Age Factors↗
PubMed1983

The hemodynamic effect of phentolamine and dobutamine after open-heart operations in children: influence of the underlying heart defect.

The hemodynamic effects of phentolamine alone and in combination with dobutamine were studied in the immediate postoperative period in two groups of children. Group 1 (N = 6; mean age, 152 months) had open-heart operation for acquired mitral valve disease. Group 2 (N = 6; mean age, 60 months) had intracardiac repair for tetralogy of Fallot. Before drug administration, cardiac index did not differ between groups, but patients with tetralogy of Fallot had a higher heart rate and smaller stroke volume index; systemic vascular resistance was high in both groups. With phentolamine (10 micrograms/kg/min), cardiac index and stroke volume index increased similarly in both groups (+ 13% for cardiac index in Group 1, +9% in Group 2), while systemic vascular resistance, pulmonary vascular resistance, and pulmonary wedge pressure decreased. When dobutamine (5 micrograms/kg/min) was added, there was a further increase in cardiac index in both groups, but it was greater in Group 1 (+17% vs +12%, p less than 0.01, compared with phentolamine alone; +33% vs +22%, p less than 0.01, compared with control). Systemic vascular resistance remained unchanged and heart rate increased in both groups, so that the left ventricular stroke work index increased. Although stroke volume index increased significantly with dobutamine in Group 1 (+11%, p less than 0.01), it remained unchanged in Group 2 (+3%, not significant). Thus in Group 2, dobutamine increased cardiac index only by increasing heart rate. This suggests that the relatively small, noncompliant left ventricle in patients with tetralogy of Fallot cannot further respond to inotropic drugs by increasing stroke volume index.

Adolescent↗
PubMed1983

Calcified left ventricular aneurysm in a 6-year-old boy. Case report.

The case of a calcified left ventricular aneurysm in a 6-year-old asymptomatic boy is presented. The anomaly was discovered on a routine chest X-ray. The etiology of this condition is discussed. A review of the literature reveals that this is a rare occurrence in children and that the origin is often unknown. Selective left coronary arteriography showed no arterial anomalies but early filling of the right coronary veins, apparently through small AV fistulas. This might have caused some peripheral myocardial underperfusion, followed by myocardial infarction and aneurysm formation. Aneurysmectomy was carried out uneventfully.

Calcinosis↗