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Biomedical subjects

C Pernot

Publications and source records attributed to C Pernot.

At least 55 records · Page 3Linked to original sources
PubMed1988

[Percutaneous transluminal valvuloplasty in aortic valve stenosis in children].

Percutaneous transluminal balloon valvuloplasty has been used in children since 1983 to treat tight aortic valve stenosis. Although more than 100 cases have been published, its indications compared with those of surgical valvulotomy have not yet been clearly defined. Twelve patients with tight aortic valve stenosis underwent transluminal balloon valvuloplasty: 3 were infants whose ages ranged from 1 month and 24 days to 3 months and 23 days (mean 80 +/- 13.7 days), and 9 were children aged from 4 to 17 years (mean 10.44 +/- 4.61 years). Aortic regurgitation grade I (5) or grade III (1) was present in 6 cases. An 8-year old child had previously undergone surgical aortic valvulotomy simultaneously with repair of aortic coarctation. Other associated malformations were congenital grade III mitral regurgitation in 1 case and Turner's syndrome in 1 case. Dilatation was performed with one or two successive balloons in 11 patients and with two balloons concomitantly in 1 patient. The diameter of the balloon (or the sum of those of the two balloons) was 77 to 112 percent of the diameter of the aortic annulus, but in one case this figure rose to 119 percent after failure of dilatation with a smaller balloon. One infant died at the end of the dilatation, due to perforation of the left ventricle. Another infant developed inferior myocardial infarction which followed a favourable course and left minimal sequelae.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve Stenosis↗
PubMed1988

[Cardiac stimulation in children. 20 years' experience].

Between July, 1967 and December, 1987, 71 children and adolescents (43 boys, 28 girls) aged from 9 days to 20 years (mean 7.8 years) underwent pacemaker implantation. In 91 p. 100 of the cases this treatment was performed for complete atrioventricular block (CAVB). Surgical CAVB was the reason for 59 p. 100 of implantations (correction of tetralogy of Fallot and, more recently, of complex cardiopathies), the second main reason (16.9 p. 100) being nonsurgical CAVB associated with heart disease; the children in this group were young (mean age 4.2 years), and the prognosis mainly depended on the heart disease. Isolated congenital CAVB accounted for only 8.5 p. 100 of pacemaker implantations; these were older children (mean age 13.7 years), and the decision to implant was often difficult to reach in the absence of major functional disorders; following implantation, it was frequently found that isolated congenital CAVBs regarded as being well tolerated in fact were unrecognized handicaps. Acquired CAVB (7 p. 100) mostly consisted of Kearns' syndrome (4/5 cases). In addition, 3 children with sinus node disease and 1 with Romano-Ward syndrome benefited from cardiac pacing. Seven children died; death was in no case due to pacing but to the heart disease associated with CAVB. Endocardial pacing (68.2 p. 100 of primary implantations during the last decade) was preferred to epicardial pacing. Since 1985 we have been using exclusively screwed endocardial monopolar electrodes. The pacemakers were usually of the single-chamber ventricular type (85.9 p. 100 of primary implantations), but since 1987 dual-chamber pacemakers have been increasingly preferred for children with permanent CAVB or for replacement of pacemaker cases. Single-chamber noncompetitive ("demand") pacemakers were implanted in only 2 children: one pacemaker was connected to a ventricular electrode (atrial paralysis), the other to an atrial electrode. Whatever the type of electrode used, the pacemakers were implanted in the abdominal region in very young infants and in the pectoral region in children older than 3 or 4 years. Breakage of the wire was the main complication. Rises in threshold are the major drawback of epicardial pacing, as they require reoperation when the energy delivered cannot be effectively programmed. Endocardial pacing, preferably with a dual-chamber instrument, seems to be the best method, being the least aggressive, with minimal complications in short and very long term; it is justified as first-line treatment of permanent or predominant CAVB.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

[Should the Isuprel test be performed systematically in Wolff-Parkinson-White syndrome?].

The isoprenaline (Is) test was designed by Wellens et al. in 1982 to evaluate the effect of catecholamines on the effective refractory period (ERP) of Kent's bundle (K). The purpose of our study was to assess the value of this test in the prognosis of Wolff-Parkinson-White syndrome (WPW), to define its criteria of severity and to determine the usefulness of the test. Out of 33 patients with WPW syndrome, 10 (group I) had a clinical history of severe arrhythmia and 23 (group II) were asymptomatic or had paroxysmal nodal tachycardia. The prognosis of WPW syndrome was evaluated by measuring Kent's bundle ERP under coupled atrial stimulation (S1 S2) and the shortest cycle conducted by K during induced atrial fibrillation (AF) and atrial pacing (AP) both in the basal state (B) and under a 20-30 micrograms Is infusion. (table; see text). Analysis of the results showed constant shortening of ERP in group I and reproduction of the clinical tachycardia in 6 cases. In group II patients isoprenaline unmasked the WPW syndrome in 3 cases and reproduced the clinical tachycardia in 5 cases. The ERP of Kent's bundle evaluated by S1 S2 became smaller or equal to 220 ms in 70 p. 100 of the cases, and this shortening was not specific. The shortest cycle in AF or AP became inferior of equal to 220 ms in only 6 cases, the history being concordant with clinical findings in 4 of them. Altogether, the most reliable and simplest way of evaluating the severity of WPW syndrome is the highest frequency conducted by Kent's bundle in atrial pacing during the Is test which should be performed in all patients in view of its specificity, simplicity and safety.

Adolescent↗
PubMed1988

[Contribution of MRI to the diagnosis of double aortic arch].

The authors present a case of double aortic arch explored by MRI and discuss the advantages and disadvantages of MRI as compared to other noninvasive imaging methods, such as ultrasounds and digital angiography, in congenital pathology of the aorta. Because it provides good quality images, can explore the aorta in all three dimensions, has optimal vascular contrast without contrast injection and carries no risk, MRI is indispensable in all cases where ultrasonography finds its limitations. Besides, the subjective factor inherent in the operator is very small, and MRI is the best available method to study the relations between the aorta and the surrounding organs; this is particularly important in case of double aortic arch owing to compression of the neighbouring organs with, notably, stridor. However, the vascular map is less accurate than with angiography, and the cost, the problem of access to the machines and the long time required for acquisitions limit the use of MRI.

Aorta, Thoracic↗
PubMed1988

[Results of programmed ventricular stimulation in primary dilated cardiomyopathy].

Programmed ventricular stimulation (PVS) has been advocated as being capable of identifying patients with idiopathic non obstructive dilated cardiomyopathy (NOCM) and at high risk of sudden death. We have studied the results of that method in 56 patients aged from 29 to 69 years (mean 53 years) presenting with idiopathic NOCM. The patients were divided into two groups according to the presence or absence of ventricular tachycardia (VT). Group I (controls) comprised 23 patients without documented VT. Group II consisted of 33 patients with documented VT which was sustained in 5 cases. Finally, 7 patients from both groups experienced losses of consciousness. Ventricular stimulation was performed on 2 sites of the right ventricle, using 1 to 3 extrastimuli on 2 imposed cycles. It was repeated under isoprenaline on 25 occasions. PVS induced non sustained ventricular tachycardia (NSVT) in only 2 patients of group I; it reproduced the sustained ventricular tachycardia (SVT) observed in the 5 patients with spontaneous SVT. PVS was negative in 14 of the 28 patients with NSVT; it induced NSVT in 8/28 and SVT in 6/28 (including 4 with more than 280 beats/min). The isoprenaline test failed to induce SVT. 7 patients died suddenly: 3 presented with SVT and 4 had syncopes and NSVT; ventricular stimulation induced SVT in 3 of these 4 patients. It is concluded that induction of sustained VT is uncommon in NOCM, but a history of syncope should prompt a search for SVT. Patients with spontaneous symptomatic NSVT and inducible SVT must be considered at high risk of sudden death.

Adult↗
PubMed1988

[Idiopathic laryngotracheobronchial calcifications in children. Apropos of 2 cases].

Calcifications of cartilage in the larynx, trachea and bronchi are rare in children. Two cases reported and listed with 5 similar cases of the literature. Such calcifications are generally discovered in young children and congenital stridor is commonly associated with. Calcifications of bronchi are not present in every case. The blood calcium is normal. Laryngoscopic examination shows in two cases a laryngeal stiffness. The prognosis is good. In two cases, one of the parents of under 40 years old, also had calcifications of the trachea and of the bronchi.

Adolescent↗
PubMed1987

[Prognosis of spontaneous occlusions in tight coronary stenosis].

Eighteen out of 408 patients assigned to coronary angioplasty rapidly developed complete obstruction of the vessel to be dilated. The results of a retrospective study of clinical, biochemical, angiographic and/or angio-scintigraphic events in these 18 patients are reported. The interval between the two coronary arteriographies was 67 +/- 66 days. Angina was initially unstable in 9 patients and stable in 6; 3 patients were asymptomatic. Coronary lesions followed the usual distribution pattern: the left anterior descending artery was involved in 11 cases, the circumflex artery in 4 cases and the right coronary artery in 3 cases. Overall, the degree of stenosis was high (86 +/- 7%); Following obstruction the course of the disease was favourable in 11 patients (61%), with complete remission of all symptoms in 5. Six patients remained with unstable angina. Apart from one case of sudden death, none of the patients developed myocardial infarction, as shown by the absence of significant biochemical, electrical and angiographic changes. The importance of pre-existing or newly developed collateral circulation as a good prognosis factor is highlighted.

Adult↗
PubMed1987

[Sudden death during Holter recording. Possible iatrogenic role of cardiovascular drugs. 10 cases].

Ten patients who presented with advanced heart disease and severe ventricular arrhythmia could be considered "at high risk of sudden death" caused by ventricular fibrillation. Yet they died suddenly while under Holter monitoring, and the recordings demonstrated that 4 of these deaths were due to a major disorder of conduction and 6 to ventricular fibrillation. Further analysis of these cases showed that the lethal disturbance of heart rhythm was ascribable to an anti-arrhythmic drug in 5 cases (2 with conduction disorder, 3 with ventricular fibrillation). It would appear that although patients of this kind need anti-arrhythmic drugs, these should be given with caution and in lower doses than in patients with normal left ventricular function.

Adult↗
PubMed1987

Effect of flecainide on left ventricular ejection fraction.

Antiarrhythmic agents may depress cardiac contractility and worsen heart failure. Flecainide is an effective antiarrhythmic drug, but when administered orally in patients with left ventricular (LV) dysfunction, its effect on LV function is unknown. To assess the effects of flecainide on cardiac function, LV ejection fraction (LVEF) was measured by radionuclide ventriculography in 36 patients with LV dysfunction (LVEF less than or equal to 40%), prior to, and 7 days after, drug therapy was initiated. To analyse the possibility of a dose-dependent effect on LVEF, 18 patients received 200 mg day-1 of flecainide and 18 patients with an identical initial LVEF (27 +/- 8 vs 27 +/- 9) (NS) received 300 mg day-1. The study was stopped in 7 patients because of severe cardiac adverse effects; in these patients the LVEF was significantly lower (15 +/- 7) than that of the 29 patients who completed the protocol (27 +/- 8) (P less than 0.01). In patients who completed the protocol, there was no significant change in LVEF either with a daily dosage of flecainide of 200 mg day-1 (27 +/- 8 vs 27 +/- 8) or with 300 mg day-1 (27 +/- 9 vs 28 +/- 13). Thus, in the patients with LV dysfunction studied, oral flecainide did not significantly affect LV function either with a low or with the usual daily dosage. However, in patients with severe impairment of LV function (LVEF less than 30%) flecainide must be used carefully owing to a higher incidence of adverse effects on cardiac rhythm.

Arrhythmias, Cardiac↗
PubMed1987

Inducible multiform ventricular tachycardia in Wolff-Parkinson-White syndrome.

The induction of ventricular tachycardia by ventricular stimulation was investigated in 46 patients with isolated Wolff-Parkinson-White syndrome (10 concealed) and 36 control patients with normal electrocardiograms and conduction systems. None of those studied had spontaneous ventricular arrhythmias or myocardial or valve disease. Single and double ventricular extrastimuli were delivered at 3 cycle lengths (sinus, 600 ms, 400 ms). In the controls ventricular simulation induced one episode (3%) of non-sustained ventricular tachycardia. Ventricular stimulation in patients with Wolff-Parkinson-White syndrome induced two episodes of ventricular fibrillation and 15 episodes of non-sustained multiform ventricular tachycardia (37%). Ventricular arrhythmias were induced only in patients with overt Wolff-Parkinson-White syndrome. In 14 patients the conformation of the electrocardiogram at the start of ventricular tachycardia resembled that of major pre-excitation. The absence of inducible ventricular tachycardia in patients with concealed Wolff-Parkinson-White syndrome suggests that anterograde conduction via an atrioventricular accessory pathway is required to initiate the ventricular arrhythmias: the ventricular tachycardia may be associated with reentry of impulses via atrioventricular connection during the phase of ventricular vulnerability. The similarity between the start of ventricular tachycardia and pre-excitatory complexes may also indicate local reentry into the ventricular area occupied by the bypass tracts. Patients with Wolff-Parkinson-White syndrome and anterograde pre-excitation are more likely to have inducible multiform ventricular tachycardia than individuals without Wolff-Parkinson-White syndrome.

Adolescent↗
PubMed1987

[Current role of radionuclide imaging in pediatric cardiology].

Three main nuclear medicine methods are used in paediatric cardiology: sequential first-pass radionuclide imaging of the cardiac cavities, radionuclide equilibrium ventriculography and radionuclide myocardial imaging. Valuable functional information is obtained, and invasive explorations can be avoided in an ever increasing number of cases. Of particular interest is left-to-right shunt measurement which indicates that atrial septal defects must be surgically corrected when the pulmonary/systemic flows ratio (QP/QS) is above 2. This technique is also useful to evaluate the tightness of repairs in ventricular and atrial septal defects. Radionuclide studies of the right and left ventricles may detect dysfunction in one or the other cavity. The left ventricular ejection fraction is reduced in myocardiopathy an in aortic or mitral valve diseases seen at a late stage. The right ventricular function is often abnormal, notably during exercise, after repair of the tetralogy of Fallot and after atrial correction of complete transposition of the great arteries. An altered ejection fraction in patients with single ventricle is also a sign of deterioration. Right ventricular diastolic overload evaluated by radionuclide equilibrium ventriculography correlates with the QP/QS ratio value in atrial septal defects and with the inducibility of ventricular tachycardia by endocavitary pacing in repaired tetralogy of Fallot. Thallium 201 myocardial imaging provides information on myocardial ischaemia, notably that associated with congenital abnormalities of the coronary arteries. Its use had now been extended, albeit with some limitations, to the evaluation of right ventricular systolic overload. Other radionuclide techniques are being developed with new tracers: Kryton 81m for studies of the right ventricle, short-lived radionuclides for first-pass studies, Iodine 123-labelled fatty acids for myocardial imaging. More recently, some substrates, such as deoxyglucose, have been labelled with positron emitters permitting in vivo metabolic studies.

Cardiac Output↗
PubMed1987

[Correlation between late surface potentials and inducible ventricular arrhythmias. Apropos of 115 cases].

Programmed ventricular stimulation and a search for late surface potentials (LP) by means of signal-averaging and quantification by Simson's method were performed in 115 patients divided into five groups: group I (n = 50) with no myocardial infarction (MI) and no clinical or induced ventricular tachycardia (VT); group II (n = 28) with MI and no clinical or induced VT; group III (n = 8) with MI, no clinical VT but induced non sustained VT (NSVT); group IV (n = 19) with MI, no clinical VT but induced sustained VT (SVT); group V (n = 15) with clinical and induced VT. The terminal portion of the averaged signal (AS) was analyzed by three parameters: duration of AS terminal portion less than 40 microvolts (Dur TP), AS amplitude 50 and 40 ms before its end (Amp 50, Amp 40). The presence of TP was defined in two ways: criterion A = Amp 40 less than 25 mcv, criterion B = at least two sub-criteria: Dur TP greater than 40 ms, Amp 50 less than 25 mcv, Amp 40 less than 15 mcv. Compared to groups I and II, the AS of group V was characterized by a prolonged and low amplitude terminal portion (p less than 0.001). Groups III and IV were intermediate. The incidence of TP in groups I to V was 20, 28, 37, 56 and 80% respectively with criterion A, and 4, 4, 0, 28 and 66% respectively with criterion B. The lower incidence of TP in group IV as compared to group V was probably due to the induction of purely artefactual SVT's, notably those with rapid cycle (greater than 270 cps/min) which are remarkable on several accounts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Outcome of 195 patients with Wolff-Parkinson-White syndrome].

Between 1974 and 1984, 207 patients with Wolff-Parkinson-White syndrome (WPW) were admitted to our hospital department; 195 of them were followed up for periods ranging from 1 to 12 years (6 years in children, 3 years and 9 months in adults on average); 160 had undergone electrophysiological exploration. Fifty-seven patients were less than 16 years old: 7 died, including 6 with associated congenital heart disease; an asymptomatic 12-year old girl died suddenly while taking part in a sporting event. The signs of WPW disappeared in 5 out of 10 children under 1 year of age. One hundred and thirty-eight patients were older than 15: 15 of them died, but only 3 deaths were related to WPW: one was consecutive to surgery for WPW and one to fulguration; the third patient died of WPW tachyarrhythmia; the refractory period of his Kent's bundle was short, but his compliance with treatment was irregular. We found no correlation between changes in functional symptoms and Kent's bundle refractory period values; paradoxically, the frequency of attacks and resistance to treatment was higher in cases with long refractory period. On the whole, this series confirms that WPW usually is a benign disease. However, the risk of sudden death, of which it offers an example, indicates that all patients with WPW should be evaluated with at least an exercise test and, depending on its results or on the socio-professional context, an electrophysiological exploration.

Adolescent↗
PubMed1987

[Cardiovascular dysplasia in Noonan's syndrome. Apropos of 64 cases].

The multiple malformation syndrome with characteristic facies described by Jacqueline Noonan in 1963 is one of the most commonly encountered syndromes in paediatric cardiology. The series presented here comprises 64 cases, almost a quarter of which were familial (6 families). The morphotype (Turner phenotype with hypertelorism) can easily be recognized, but the variations, progressivity and resemblance to some similar syndromes imply a detailed analysis of a wide range of discriminant features. Short stature and webbed neck are less frequent than in Turner's syndrome, while mental debility and, mostly, cardiovascular lesions are much more frequent (the latter are present in 50-60% of the cases). The most typical cardiovascular lesion is pulmonary valve stenosis with dysplastic leaflets, or "atypical pulmonary stenosis syndrome", characterized by a curious electrical axis and above all, by left ventricular myocardiopathy with very peculiar deformations at ventriculography and 2D-echocardiography. In our series, myocardiopathy was even more frequent than dysplastic pulmonary valve stenosis (71.8% versus 64%). The dissemination of dysplastic lesions must be emphasized. They involve the aorta much more often than is usually reported (one-third of the cases); lesions of the lymphatic system are less frequent but may be severe. Occasionally, entirely different heart diseases, such as Fallot's tetralogy, are encountered. Owing to the relationship between its lesions and those of other multiple malformation syndromes, notably those of the phakomatosis group, and to the possibility of borderline cases with these syndromes, or even with other dystrophies, such as Williams-Beuren dystrophia, the cardiovascular dysplasia of Noonan's syndrome must be classified within the vast group of histodysplasias which are embryonic diseases of the "layers" or "neuro-ecto-mesodermoses" of unknown genetic mechanism.

Adolescent↗