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Biomedical subjects

P Touboul

Publications and source records attributed to P Touboul.

At least 19 recordsLinked to original sources
PubMed1995

Subdiaphragmatic implantation of implantable cardioverter defibrillator generator.

Despite several improvements in the surgical technique and in the technologic design of cardioverter defibrillators made over the past years, abdominal placement of the generator device, done as Mirowski did it in his first implantation performed in 1980, remains the widely used method. Although smaller defibrillators are available, they remain bulky and are a source of local complications. To prevent such complications and to enhance patient comfort, we performed a subdiaphragmatic implantation in 31 patients.

Defibrillators, Implantable↗
PubMed1995

Wavelet analysis of high-resolution ECGs in post-infarction patients: role of the basic wavelet and of the analyzed lead.

Wavelet analysis provides a fruitful alternative to standard techniques for the detection of fractionated potentials in signal averaged high-resolution (SA-HR) ECGs. In this study, an attempt is made to optimize the discrimination of post infarction patients prone to ventricular tachycardia (VT), using wavelet analysis. Optimization is based on the choice of the ECG leads or lead combinations to be analyzed, and on the analyzing wavelet to be computed. A set of 40 post-infarction patients (20 patients with VT and 20 patients without any arrhythmia) is analyzed. Individual leads and lead combinations of the SA-HR ECGs are processed using a multiparametric algorithm, based on coherent detection of aligned local maxima of the wavelet transform. Seven basic wavelets are tested: the Morlet's wavelet, and the six first derivatives of a Gaussian function. The first derivative of a Gaussian function provides poor results, and is discarded. All other wavelets prove to perform equivalent classification. A vector magnitude computed from the wavelet transforms of the three SA-HR ECGs achieves better results than individual leads. An optimized risk stratification algorithm leads to 90% sensitivity and 100% specificity in the 40 patients learning set.

Adult↗
PubMed1995

Sotalol: from "just another beta blocker" to "the prototype of class III antidysrhythmic compound".

Sotalol is a beta-blocking drug devoid of membrane stabilizing properties, as well as intrinsic sympathomimetic actions, or cardioselectivity. In addition, sotalol prolongs atrial and ventricular repolarization (Class III antiarrhythmic activity). It appears to have less myocardial depressant effect than other beta-blocking agents. Given orally, bioavailability of the drug reaches 100%. Sotalol's plasma half-life is 15 hours (range 7-18) and is dependent only on renal function. In clinical practice, it has been found effective in the suppression of nearly all supraventricular and ventricular dysrhythmias except those related to prolonged ventricular repolarization. Most common adverse effects are dyspnea, bradycardia, and fatigue, which results in drug termination in 16% of the cases. Torsades de pointes usually associated with bradycardia and drug induced QTc prolongation has been reported in 1.9%-3.5% of the patients receiving sotalol. This complication may be reduced by limiting the dose (< 640 mg/day) especially in patients with impaired renal function. In addition hypokalemia must be avoided. To sum up, the combination of Class II and Class III effects may carry additional benefits. However, further studies are required to test such hypotheses.

Animals↗
PubMed1995

[Radiofrequency ablation of intranodal tachycardia].

The first radical approach to the treatment of atrioventricular nodal reentrant tachycardia was surgical dissection of the perinodal region. This technique has been replaced by the delivery of radiofrequency energy by an ablation catheter to the region of the atrioventricular node. The aim of this report is to describe the authors' experience of atrioventricular nodal application of radiofrequency current. The study comprised 53 cases (32 women and 21 men, mean age 46 +/- 17 years) with frequent attacks of reciprocating tachycardia. Endocavitary electrophysiological investigation confirmed the intranodal reentrant mechanism. The region of application of the radiofrequency current was located radiologically and then the precise site determined by the recording of nodal electrical activity. The appearance of junctional rhythm during the procedure was also used as a means of identification of the zone of ablation. Dual conduction persisted after ablation in 35 patients. However, no episode of tachycardia could be induced after the procedure. The AH interval increased during application of radiofrequency current in 3 cases but this abnormality regressed in the 2 months following the procedure. Recurrences of nodal reentrant tachycardia were observed in 14 cases (26%), 24 hours to 2 months after ablation. The rate of recurrence was significantly higher in patients who did not have a junctional rhythm during application of the radiofrequency current (62% vs 4%, p < 0.05). The number of recurrences was also greater in the group of patients with persistence of slow intranodal conduction after the radiofrequency ablation (p < 0.04). A second session of radiofrequency ablation was undertaken in 14 patients and a third session was required for 2 of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Systematic transesophageal echocardiography during the postoperative first 24 hours after mitral valve replacement].

Systematic transoesophageal echocardiography after the 10th day of mitral valve replacement with a mechanical prosthesis has enable diagnosis of several abnormal conditions: thrombi, strands and paravalvular leaks. The aim of this prospective study was to determine the prevalence of these conditions by biplane transoesophageal echocardiography in the first 24 postoperative hours. Transthoracic and transoesophageal echocardiography was performed on average 12 +/- 3 hours after coming out of the surgical block in 77 consecutive patients who underwent mitral valve replacement with a mechanical prosthesis. Nine patients (11.7%) had appearances of thrombi or strands in the left atrium or auricle. These small thrombi (1 to 1.5 cm2) were not obstructive. No embolic events were observed in the first month of these patients. Spontaneous contrast was seen in the left atrium of 31 patients (40%). The factors associated with the presence of thrombus or strands were advanced age (p = 0.02), presence of spontaneous contrast (p = 0.02) and more dilated left atrium (p = NS) Paraprosthetic leaks were seen in 11 cases (14.3%). In 10 cases, the regurgitant jets were narrow at their origin with little extension into the left atrium. Only one patient had severe regurgitation associated with raised transprosthetic pressure gradients. Cases with paravalvular leaks had a lower incidence of spontaneous contrast (3.2% vs 21.7%) and no thrombosis. Transoesophageal echocardiography demonstrated spontaneous contrast, thrombi and strands in the initial hours following implantation of a mechanical mitral valve prosthesis. The prevalence of these appearances, comparable to that of the results reported with later investigations, underlines the importance of effective anticoagulation from the fist postoperative hours.

Aged↗
PubMed1995

[Sustained ventricular tachycardia: an evaluation of long-term prognosis].

The authors analysed the clinical and paraclinical variables of 116 patients admitted to the Hôpital Cardiologique de Lyon between 1986 and 1990 with sustained ventricular tachycardia without cardiocirculatory arrest in order to determine the long-term outcome and the prognostic factors of death and recurrence. The average age of the patients was 56 +/- 15 years (mean +/- SD) and 83% were men. The mean ejection fraction was 39 +/- 15%. Sixty-five had previous myocardial infarction (group I); 30 (group II) had dilated cardiomyopathy (n = 21), right ventricular dysplasia (n = 4), hypertrophic cardiomyopathy (n = 2), congenital (n = 2) or valvular (n = 1) heart disease. Group III comprised 21 patients with no apparent cardiac disease or isolated mitral valve prolapse. Brief syncope was reported in 12 cases. The paraclinical investigations showed 46 patients (66%) with at least two criteria of positivity for ventricular late potentials; Holter recording showed doublets or runs of VES in 46% of cases and sustained or non-sustained VT was induced during exercise testing in 16 patients (22%). Programmed ventricular stimulation triggered VT in 85%, 79% and 61% of patients in groups I, II and III respectively. The patients were treated with amiodarone in 65 cases, a betablocker in 25 cases, catheter ablation of the origin of the tachycardia in 12 cases, antiarrhythmic surgery in 6 cases, coronary bypass grafting in 5 cases (with an associated antiarrhythmic procedure in 3 cases). An automatic defibrillator was implanted in 9 patients. The average follow-up period was 32 months (range: 17 days to 65 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Mediterranean alpha-linolenic acid-rich diet in secondary prevention of coronary heart disease.

In a prospective, randomised single-blinded secondary prevention trial we compared the effect of a Mediterranean alpha-linolenic acid-rich diet to the usual post-infarct prudent diet. After a first myocardial infarction, patients were randomly assigned to the experimental (n = 302) or control group (n = 303). Patients were seen again 8 weeks after randomisation, and each year for 5 years. The experimental group consumed significantly less lipids, saturated fat, cholesterol, and linoleic acid but more oleic and alpha-linolenic acids confirmed by measurements in plasma. Serum lipids, blood pressure, and body mass index remained similar in the 2 groups. In the experimental group, plasma levels of albumin, vitamin E, and vitamin C were increased, and granulocyte count decreased. After a mean follow up of 27 months, there were 16 cardiac deaths in the control and 3 in the experimental group; 17 non-fatal myocardial infarction in the control and 5 in the experimental groups: a risk ratio for these two main endpoints combined of 0.27 (95% CI 0.12-0.59, p = 0.001) after adjustment for prognostic variables. Overall mortality was 20 in the control, 8 in the experimental group, an adjusted risk ratio of 0.30 (95% CI 0.11-0.82, p = 0.02). An alpha-linolenic acid-rich Mediterranean diet seems to be more efficient than presently used diets in the secondary prevention of coronary events and death.

Coronary Disease↗
PubMed1994

[Diagnostic value of exercise test in the evaluation of sustained ventricular arrhythmia].

The authors undertook a prospective study comparing exercise testing and programmed ventricular stimulation in order to assess the diagnostic value and risks of exercise stress testing in patients with sustained ventricular arrhythmias. Fifty-five consecutive patients (47 men and 8 women) with an average age of 47 +/- 15 years were included. The initial condition requiring investigation was sustained ventricular tachycardia (47 cases) and ventricular fibrillation (8 cases). The patients had ischaemic heart disease (N = 18), dilated cardiomyopathy (N = 9), valvular heart disease (N = 4) and congenital heart disease (N = 3). Six patients presented with arrhythmogenic right ventricular dysplasia and 15 patients had apparently normal hearts. Four episodes of sustained ventricular tachycardia (7.3%) and 10 non-sustained ventricular tachycardia (18.2%) were induced by exercise testing. One poorly tolerated episode of ventricular tachycardia required cardioversion. No signs of myocardial ischaemia were observed in association with the induced ventricular tachycardia Patients with ventricular tachycardia induced by exercise were significantly younger (39.5 +/- 12.5 vs 49.5 +/- 15.4 years; p = 0.04) and attained a lower predicted maximal heart rate (82.2 +/- 14.6 vs 91.4 +/- 14.4%; p = 0.04), but the underlying pathologies were the same, as were the initial arrhythmias and the level of exercise attained. With respect to the clinical circumstances of induction of the initial ventricular arrhythmia, patients with ventricular tachycardia induced by exercise had an increased tendency to arrhythmias during effort or stress (7/14 vs 8/41; p = 0.06). Programmed ventricular stimulation induced more ventricular tachycardias than exercise testing (36/55 vs 14/55; p < 0.0001). The results of exercise testing were not correlated to those of programmed stimulation (p = 0.38).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Hemomediastinum caused by spontaneous rupture of the thoracic aorta].

The authors report the rare case of spontaneous rupture of the aortic isthmus in the absence of preexisting aortic aneurysm or dissection in a hypertensive woman presenting with chest pain and haemomediastinum. The history of trauma 30 years previously, could have been a predisposing factor. The diagnosis of this condition remains difficult and is often missed. The physiopathological, aetiological, clinical and diagnostic features are reviewed. Transoesophageal echocardiography showing an intraparietal haematoma confirmed the aortic origin of the haemomediastinum. Conventional angiography was of no value in the reported case because of the absence of rupture of continuity or of an intimal tear.

Aged↗
PubMed1994

[Automatic implantable defibrillators; subdiaphragmatic insertion].

Although the material and techniques of implantation of the electrodes of implantable defibrillators have been improved, the abdominal implantation of the generator remains widely used as described by Mirowski in 1980. Despite a progressive reduction in their size, the generators remain bulky and a source of local complications. The risks and discomfort of implantation in the abdominal wall led the authors to try subdiaphragmatic implantation in 22 patients. There was no morbidity with perfect healing in all 22 cases. The mean follow-up period was 11 months. The patients felt very comfortable, a significant advance with respect to abdominal implantations.

Adolescent↗
PubMed1994

[Long-term course after electric ablation of the bundle of His in the treatment of supraventricular tachycardia].

The authors report the long term results of His bundle ablation for supraventricular tachycardia in a series of 49 patients. This retrospective study was based on a patient population of 27 men and 22 women with an average age of 59 at the time of ablation, between 1984 and 1993. The indication for His bundle ablation was invalidating supraventricular tachycardia resistant to antiarrhythmic therapy in all cases. One group of patients (Group I, n = 31 patients) underwent high energy electrical shock and the second group (Group II, n = 18 patients) recruited after 1991, underwent radiofrequency catheter ablation. Complete atrioventricular block was obtained in the first group in 1 to 4 sessions whereas 17 patients of Group II were treated in a single session. During a follow-up period of an average of 40 months, 2 patients were lost to follow-up and 6 died, 3 of cardiac failure, 1 of a cerebrovascular accident, 1 of pulmonary carcinoma and 1 of unknown cause. In Group I, atrioventricular conduction persisted in 1 patient (primary failure) and reappeared in one other patient, but, in Group II, complete atrioventricular block persisted even in the patient in whom the interruption was not obtained with a single session of radiofrequency ablation. The patients were generally physically improved and satisfied not to have any palpitations. A decrease in exercise capacity estimated by the NYHA classification was observed in 38% of patients without apparent cardiac disease who developed dyspnea. On the other hand, 43% of patients with cardiac disease and in NYHA class > or = 2 were improved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Surgery for atrial fibrillation by the Cox technique. Apropos of 2 cases].

The authors report the cases of two patients who underwent surgery of atrial fibrillation by Cox's technique. In one case, it was associated with mitral valvuloplasty for atrial fibrillation of 4 years' duration; sinus rhythm was restored on the 19th postoperative day; it persisted at 11 months without antiarrhythmic drugs. On the other case, it was associated with mitral valve replacement for atrial fibrillation of 7 years' duration in a patient with dilated cardiomyopathy and a poor left ventricle; sinus rhythm was restored by electrical cardioversion during the 4th postoperative month; it persisted at 9 months with antiarrhythmic therapy. Cox's technique allows: 1) definitive suppression of atrial fibrillation, 2) restoration of atrioventricular synchronisation, 3) preservation of atrial transport function. The indications are paroxysmal or permanent atrial fibrillation, invalidating and resistant to medical therapy; atrial fibrillation of over 3 years' duration associated with mitral regurgitation requiring valvular repair and atrial fibrillation of invalidating primary cardiomyopathy.

Aged↗
PubMed1994

[Intracardiac treatment of atrial flutter by radiofrequency currents].

Though not as common as atrial fibrillation, atrial flutter is frequently encountered in everyday cardiological practice. Though generally thought to be benign, it may be difficult to treat both in respect to its conversion to sinus rhythm and prevention of recurrences. It is often poorly tolerated. There are resistant, invalidating forms for which catheter ablation of the His bundle may be considered as a last resort. This is only a palliative measure even if effective from the functional point of view. A new technique for treating atrial flutter by a direct action on the atrial tissue has been recently introduced. The basis of this method is the concept of circus movement of the activation in the right atrium, the wave front circulating in an anti-clockwise direction in common atrial flutter. The postero-inferior region of the right atrium, at Koch's triangle, is the site of slow conduction and the target of choice for catheter ablation. The detection of this zone is determined by the endocavitary recording of fragmented, prolonged electrogrammes and by atrial stimulation techniques. The application of radiofrequency currents on these bases (high energy shocks are rarely used nowadays) results in interruption of atrial flutter. However, there are no data available concerning the long-term efficacy of this technique. Since 1992, our group has used an anatomical approach for catheter ablation. This aims to apply the radiofrequency current on the isthmus of atrial tissue between the orifice of the inferior vena cava and the tricuspid annulus through which the flutter wave front passes to reach the interatrial septum.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Flutter↗
PubMed1994

[Infectious endocarditis induced by Actinobacillus actinomycetemcomitans. 8 new cases].

A commensal organism of the buccal cavity, Actinobacillus actinomycetemcomitans (AAC) has been responsible for at least four new cases of infectious endocarditis by year in France. This retrospective study was based on 90 new cases of infectious endocarditis by AAC, including 8 personal observations. One third of patients had no known cardiac disease before their infectious endocarditis, the portal of entry of which was usually dental. In cases of suspected infectious endocarditis, rapid and severe weight loss (43% of cases) and, less commonly, anicteric cholestasis (8%) should alert the physician for the possible pathological role of AAC. The echocardiographic appearances are non-specific. The diagnosis is confirmed on blood cultures but the organism grows slowly in CO2 enriched atmosphere. Initially, the course of the disease was favourable in one third of patients but, in two thirds of cases, complications were observed almost renal (26%), cardiac (24%) and neurological (18%). Two thirds of patients were cured by the time they were discharged whereas the remainder had sequellae, mainly valvular and neurological. The hospital mortality was 9%; late mortality was 6%. Therefore, the prognosis of AAC endocarditis, seems to be better than that of other bacteriological forms. A combination of cephalosporin and aminoside, or even a simple third generation cephalosporin antibiotic therapy for at least 4 weeks are usually effective. The complementary surgical indications are the same as for other forms of infectious endocarditis. Prophylaxis depends on strict prophylactic amoxicillin therapy for all cardiac patients at risk of infectious endocarditis before dental treatment and on good bucco-dental hygiene.

Actinobacillus Infections↗
PubMed1994

[Control of ventricular response in patients with atrial fibrillation].

The underlying treatment of atrial fibrillation comprises two possible options. In the best of cases, sinus rhythm obtained by cardioversion must be maintained by appropriate therapy. This solution is the best option for preventing the risks of embolism or of myocardial deterioration. In refractory cases, the remaining option is to control the ventricular response. The principle is to maintain the rhythm within acceptable limits (70 to 90/min at rest), an action which also aims to limit the response to effort. This results in a symptomatic improvement and protects myocardial function. Digitalis is the commonest drug used for controlling the ventricular response. It is usually successful at recommended therapeutic doses, but often fails to control the response to effort. Adjustment of dosage using plasma concentrations may improve the situation. Another method of improving the control of the ventricular response is to associate digitalis with beta-blockers or calcium inhibitors. The risk of this option is the induction of an excessive bradycardia but, on the other hand, the response to exercise can be reduced and the variations of ventricular response decreased over a 24 hour period. In forms resistant to pharmacological treatment, it is possible to intervene directly on the atrioventricular conduction pathways. Radio frequency current is used in this indication. Sometimes, the objective is only to alter atrioventricular conduction to reduce the ventricular response to atrial fibrillation. In fact, this is often difficult to obtain and a number of cases develops complete atrioventricular block. In general, the aim is to create complete atrioventricular block which is then associated with implantation of a pacemaker.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1993

[What is a practical approach to atrial extrasystole?].

Atrial premature beats are caused by premature and abnormal depolarization of the atria, responsible for an anticipated QRS complex. Usually, the shape of this complex is identical to that of sinus beats. The diagnosis is made by electrocardiography, but it may meet with problems due to lack of recognition of premature P waves (and the more so as these may not give a ventricular response) or to the deformation of the QRS complex by a bundle branch block mimicking a ventricular premature beat. As in all instances, premature atrial beats are generally followed by a pause. Atrial premature beats, isolated in most cases, may trigger off supraventricular tachycardia episodes of varying duration. The clinical expression of atrial premature beats ranges from perceptible palpitations to complete latency. The decision to treat is determined by the functional repercussions of the disorder. Supplementary data are always useful to evaluate the significance of the disorder. Using the Holter recording system makes it possible to count the premature beats over a 24 h period, to find out whether they are preponderant in day time (suggesting an adrenergic factor) or at night (suggesting vagotonic disorders), and to identify bouts of atrial fibrillation that would have not been felt. Investigations for an underlying heart disease are mandatory. Any one of the cardiopathies of adulthood, and notably mitral valve lesions, may be encountered, as well as congenital heart diseases such as interatrial communication. The frequency of atrial premature beats tends to increase as cardiac failure develops, and its course can be made worse by some drugs (such as digitalis compounds) or by metabolic disorders (e.g. hypokaliaemia). However, there are many cases where no cardiopathy is detected. Within the group of isolated atrial premature beats, disorders found in athletes (in theory manifestations of hypervagotonia) can be individualized. In practice, therapeutic abstention is the rule, especially when premature beats are latent. In cases with poor functional tolerance, nervous sedatives of beta-blockers may be useful. Antiarrhythmic drugs are rarely necessary, but they may be prescribed if episodes of paroxysmal atrial fibrillation are present.

Cardiac Complexes, Premature↗