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P Blanchot

Publications and source records attributed to P Blanchot.

At least 19 recordsLinked to original sources

Closed-chest ablation of retrograde conduction in patients with atrioventricular nodal reentrant tachycardia.

We applied a new technique of catheter ablation to treat atrioventricular nodal reentrant tachycardia and preserve anterograde conduction, performing this procedure in 21 patients with repetitive episodes of tachycardia refractory to antiarrhythmic drugs. Using atrial activation in the His-bundle lead as a reference, we selected the optimal site of ablation by positioning an electrode catheter so that atrial activation occurred simultaneously with or earlier than the reference activation during tachycardia. At this site, the His-bundle deflection was completely absent or was present only at a low amplitude (less than 0.1 mV). In the majority of patients, these criteria could be met by withdrawing the catheter 5 to 10 mm from the site of the His-bundle recording (adjacent to the reference catheter). Shocks of 160 or 240 J were delivered at this site (cumulative energy [mean +/- SD], 689 +/- 442 J). Treatment resulted in preferential abolition or impairment of retrograde nodal conduction. Anterograde conduction, although modified, was preserved in 19 patients; complete heart block persisted in 2 patients. Sixteen patients remained free of arrhythmia, without medication or implantation of a pacemaker, for a mean follow-up period of 14 +/- 8 months (range, 7 to 42). Tachycardia was not inducible in 14 patients in a follow-up electrophysiologic study performed 3.6 +/- 6 months after the procedure. We conclude that catheter ablation is an effective alternative for the treatment of atrioventricular nodal tachycardia in patients with drug-resistant tachycardia.

Adult↗

[The stunned myocardium. A new pathological entity].

A 70 years old woman presented with clinical, electrical and haemodynamic evidence of myocardial infarction. The course of the disease was unusual in that enzyme levels were not increased and the electrocardiogram and ventricular kinetics returned to normal 25 days after the infarction. This syndrome was typical of electrical and mechanical myocardial stunning. The physiopathological theories behind this post-ischaemic transient myocardial dysfunction syndrome and its practical consequences are presented.

Aged↗

Fulguration of ventricular tachycardia using high cumulative energy: results in thirty-one patients with a mean follow-up of twenty-seven months.

Catheter electrical ablation of ventricular tachycardia (VT) was attempted in 31 patients (57 +/- 15 years) who had refractory recurrent VT. Fifteen patients had coronary artery disease, seven had arrhythmogenic right ventricular dysplasia, four had cardiomyopathy and five had no structural heart disease. Ten patients were NYHA class III-IV. Ten patients experienced cardiac arrest or syncope during VT. Twenty-two patients had only one documented morphologic type of spontaneous VT. Whereas nine patients had more than one: the VT was incessant or daily in 17 patients. One to 16 shocks (mean 5.6) of 160 to 240 joules each (1162 +/- 1060 joules) were delivered to the endocardial exit site of VT--as identified by endocardial activation mapping (29 patients) and pacemapping (31 patients)--during one (22 patients) or more than one session (nine patients). Cumulative delivered energy was 840 +/- 558 joules for right ventricular VT (11 patients) and 1362 +/- 1240 joules for left ventricular VT (20 patients). Reversible side effects occurring immediately after shocks included: nonclinical VT (two patients), ventricular fibrillation (two patients), AV block (three patients). Mean CK-MB fraction 6 hours after shocks was 91 +/- 46 IU/1. An electrophysiology study performed 7 to 10 days later demonstrated that the original clinical VT was inducible in seven patients, nonclinical monomorphic VT was inducible in eight patients and no VT was inducible in 13 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Immediate complications of fulguration of ventricular tachycardia and accessory pathways. Analysis of 318 endocavitary shocks].

Abnormal events occurring immediately following electric stimulation were studied in 85 patients--mean age 38.5 years (14-78)--during the performance of 318 intracardiac shocks applied in 110 sessions. This electric stimulation was done for treatment of tachycardias related to an accessory pathway (series AP: 64 patients), or ventricular tachycardias (series VT: 21 patients). The number of shocks per session was 2.4 +/- 1.4 and 4.6 +/- 3, for the series AP and VT respectively, and the cumulative energy per session, was 405 +/- 221 J and 1,007 +/- 735 J. Only events occurring within the first 30 minutes following the shocks, were evaluated. In the series AP, the 64 patients received a total of 208 shocks in 86 sessions, and 68 abnormal events were observed (33%): 35 complete atrio-ventricular blocks, of more than 10 seconds (17%), 29 sinus pauses exceeding 3 seconds (14%) and able to stretch to 30 seconds, 3 ventricular fibrillations (1.4%) and 1 atrial fibrillation. In the series TV, 21 patients received 110 shocks in 24 sessions, and only 10 abnormal events occurred (9%): 2 transient episodes of electromechanical dissociation (1.8%), 3 uniform VT (2.7%), 1 complete atrio-ventricular block (10 min.), 1 cardiac pause (4 sec), 1 ventricular fibrillation, 1 isolated haemodynamic depression and 1 Prinzmetal syndrome. All these events were temporary, 5 ventricular arrhythmias in 6 were treated with a new intracardiac shock, and there were no deaths related to electric stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Catheter ablation of accessory pathways with a direct approach. Results in 35 patients.

Thirty-five consecutive patients with an overt accessory pathway, all but two suffering from arrhythmia (atrial fibrillation, reciprocating tachycardia, or both), underwent attempted transcatheter ablation (fulguration) of their accessory pathway. Thirty-three patients had been treated with a mean of 2.3 +/- 1.4 antiarrhythmic drugs. A standard bipolar catheter was positioned on the internal surface of the right or left atrioventricular anulus with 1) a subclavian approach of the right cardiac cavities in 29 patients with right-sided accessory pathway (n = 27) or left posteroseptal accessory pathway (n = 2), 2) a patent foramen ovale in five patients (two with a left posterolateral accessory pathway and three with a left parietal accessory pathway), and a transseptal catheterism (one patient with a left parietal accessory pathway). Cathodic shocks (mean, 4.3 shocks/patient) with a mean cumulative energy of 690 J enabled the ablation (disappearance of both anterograde and retrograde conduction) of the accessory pathway in 32 patients with a follow-up ranging from 1 to 32 months (mean, 10 +/- 8 months). Two of the remaining three accessory pathways were impaired: one pathway became intermittent, the anterograde effective refractory period of the second pathway increased from 260 to 410 msec, and the third pathway was slightly impaired. This latter patient is the only one who still requires therapy, with a single antiarrhythmic drug. All others are free of arrhythmias and require no therapy. Not using coronary sinus catheterism inclusive of its os has led to only a few, benign side effects. Only one third-degree atrioventricular block occurred in a posteroseptal accessory pathway ablation. Three cases of patients with incessant reciprocating tachycardia involving a further successful ablation occurred at the beginning of our experience. The best area for ablation is, in our opinion, the recording site for the Kent-bundle activity (18 of 35 patients), but a meticulous mapping of the atrioventricular anulus during orthodromic reciprocating tachycardia makes ablation possible when the shortest ventriculoatrial time (V-A') can be recorded with reliability (mean, 85 +/- 18 msec). Such a procedure is an alternative to surgical ablation regardless of the location of the accessory pathway--not only posteroseptally.

Adult↗

[Contribution of specific potential monitoring in the expression of accessory pathways].

The electrocardiographic expression of preexcitation results from the electrophysiological behaviour of the 2 conduction pathways: the normal pathway and the accessory pathway (AP). Its interpretation can only be deductive since the electrical activities of these 2 pathways are not recorded simultaneously. The validation of a K potential likely to represent Kent's bundle activation is based on criteria of exclusion of other origins (atrium, His bundle, ventricle). The K potential could be obtained in 16 of 32 consecutive studies. In 2 cases the unusual behaviour of the AP could be reliably studied owing to recording of the K potential. In case n. 1 a 35 ms increment in conduction was reproducibly observed by atrial extrastimulation at the atrium-Kent's bundle interface. In case n. 2 preexcitation was expressed on ECG only when the atrial rate was 70 to 100/mn. With lower atrial rates conduction in the AP was impaired by a 1st degree block with an atrium-Kent's bundle delay of 100 ms. Atrial acceleration reduced this delay to 40 ms, showing that this improvement in conduction reflected an initial block on the AP in phase IV. With higher atrial rates a block was observed on the AP in phase III either as an abrupt rupture of the atrium-Kent's bundle conduction, or as a block following progressive increment of the Luciani-Wenckebach type. Injection of ATP 20 mg produced and anterograde block on the AP at the atrium-Kent's bundle interface. Retrograde conduction seemed to be lacking in the AP since atrial activity was completely dissociated from induced ventriculograms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Treatment of refractory ventricular tachycardia using cumulative high-energy fulguration].

Intracardiac electrode catheter ablation of arrhythmogenic foci, using cumulative high energy, was attempted in 29 patients (mean age 57 +/- 15 years) presenting with ventricular tachycardia (VT) refractory to antiarrhythmic drugs. A heart disease, present in 25 patients, was responsible for severe heart failure in 10 of them; 13 patients had myocardial infarction, 7 had arrhythmogenic dysplasia of the right ventricle, 5 had cardiomyopathy (dilated in 4, hypertrophic in 1). The myocardium was apparently normal in 4 patients, 2 of whom had mitral valve prolapse. Morphologically, VT was single in 20 cases, double in 4 cases and more than triple in 5 cases; arrhythmia was continual or occurred several times a day in 17 cases. In one (20 patients) or several (9 patients) catheter ablation sessions, 1 to 16 cathodic shocks of 160 to 240 Joules (1.180 +/- 1.062 J) were delivered after mapping and focal stimulation without irreversible adverse reaction. The cumulative energy delivered was 840 +/- 558 J in the right ventricle (11 patients) and 1.390 +/- 1.244 J in the left ventricle (18 patients). During a 23.4 +/- 12 months follow-up period, 4 patients died (2 of heart failure, 1 of a hitherto undocumented VT, 1 suddenly of bradycardia-asystole). VT was regarded as being controlled in 23/27 patients, 15 of whom were not taking antiarrhythmic agents. The presystolic potential during VT was -5 + 5 ms in the 4 failure cases versus -41 + 29 ms in the successful cases (p less than 0.05). It is concluded that electrode catheter ablation is an effective curative treatment of VT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Electrophysiologic effects of intravenous flecainide in intranodal junctional tachycardia in 30 patients].

The electrophysiological effects of flecainide acetate were studied in 30 patients (10 men, 20 women, mean age 48.3 +/- 18 years) suffering from sustained re-entrant intranodal tachycardia. A 2 mg/kg dose of flecainide administered over 10 minutes was given after the onset of sustained tachycardia within 3.8 +/- 2.3 min in 25 of the 30 patients; this was effected by a block in the retrograde leg of the circuit in 22 patients and by a block in the anterograde leg in 3 patients. In the remaining 5 patients the tachycardia was slowed down (367 +/- 27 ms vs 431 +/- 48 ms) chiefly by prolongation of the atrioventricular anterograde conduction. No significant side-effect was observed while the drug was being injected. Following treatment with flecainide, tachycardia was no longer inducible in 24 out of 30 patients (A) and it remained inducible in 6 patients (B, non-responders). The initial electrophysiological exploration revealed differences between these two groups in retrograde conduction: prolongation of the ventriculoatrial time during incremental ventricular stimulation (A: 41 +/- 32 ms vs B: 81 +/- 142 ms, p less than 0.05) and prolongation of the atrioventricular time above 100 ms (A: 2/24 patients, B: 3/6 patients, p less than 0.01). The following electrophysiological parameters were significantly (p less than 0.01) ,modified after intravenous flecainide: AH and HV conduction intervals, atrial refractory periods, anterograde and retrograde atrioventricular conduction. Complete retrograde block was observed in 12 patients of group A. Thus, in this study flecainide arrested a reciprocal intranodal rhythm in 25 out of 30 patients and prevented the reinduction of tachycardia in 24 of these.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Catecholergic ventricular tachycardia. Apropos of a case with associated anomalies of the QTu interval].

The case of a patient presenting syncopal catecholergic ventricular tachycardias associated with abnormalities of the interval QTu is reported. EKG at rest shows a normal or sometimes lengthened repolarization. The least effort or emotion produces a His rhythm accompanied with lengthening of QTu. Three stress tests disclose the caricatural picture of a catecholergic ventricular tachycardia. Treatment with quinidin derivatives causes a constant lengthening of QTu without modifying the profile of the stress test. The patient died suddenly. This case seems to represent an intermediate form between catecholergic ventricular tachycardia and the syndrome of long congenital QT.

Adolescent↗

[Oral flecainide in the treatment of refractory arrhythmias. Long-term follow-up of 98 patients].

Oral flecainide was administered to 98 patients with arrhythmias regarded as resistant to other antiarrhythmic agents: quinidines (82), propafenone (40), beta-blockers (30), amiodarone alone (38) or combined with a class I compound (19). Therapeutic effectiveness was assessed on clinical date, repeated Holter recordings (64 patients), exercise tests (8) and electrophysiological exploration (15). Mean follow-up was 11.7 +/- 11 months; the patients treated have now been followed up for 18.2 +/- 12 months (range: 7-58 months). Fifty-three patients had atrial arrhythmia (fibrillation or flutter in 45, atrial tachycardia in 8). Flecainide was effective in 26 patients (49%) and ineffective in 27 (51%). There was no significant difference in dosage between these 2 groups: 231 +/- 62 mg/day and 265 +/- 61 mg/day respectively. Paroxysms of re-entrant junctional tachycardia were controlled in 6 of the 8 cases observed. Eleven patients presented with Wolff-Parkinson-White syndrome: treatment was successful in the 3 patients with atrial fibrillation and in 8 of the 10 patients with orthodromic reciprocating rhythms. Among 30 patients with episodes of ventricular tachycardia, 9 (30%) responded to flecainide and 21 (70%) failed to respond. Flecainide reduced the repetitive forms by more than 90% in 7/15 patients and suppressed exercise-induced ventricular tachycardia in 2/8 patients. Fifteen out of 18 patients had ventricular tachycardia reproducible by programmed stimulation; under flecainide, the ventricular tachycardia spontaneously recurred in 4 cases, was provoked by stimulation in 5 other cases, was more easily inducible in 3 cases and was not inducible in a sustained manner in the last 3 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Incidence of short-term arrhythmias after endocavitary fulguration].

The potential short-term arrhythmogenic role of catheter-mediated electrical ablation was studied in 61 patients of mean age 44 years (range 15-80 years) who underwent this procedure for Wolff-Parkinson-White syndrome (36 patients) or ventricular tachycardia (VT, 25 patients). Continuous ECG monitoring was pursued during the 24 hours that preceded and followed ablation. Only bursts of 3 consecutive beats or more were considered significant. Recordings were performed with either a Hewlet Packard 78720 A arrhythmia recorder or a Holter readout system (Oxford Medilog 2, Marquette). In 36 patients with an accessory conduction pathway the 160 J were delivered at the annulus fibrosus cordis. Post-ablation recordings showed: VT bursts in 16 patients (17%); the bursts disappeared in every case before 3 days; in 3 patients the electrogram at the site of ablation was predominantly ventricular (p less than 0.05); frequent or subintrant attacks of reciprocal orthodromic rhythm (RR); in 3 cases RR began on simple variations of heart rate; it reflected a loss of the anterograde conduction hidden in the accessory pathway and required a second ablation; in 1 case RR initiated by VT bursts revealed the presence of a second accessory pathway; atrial tachycardia bursts, spontaneously resolved, in 4 patients (11%). No atrial fibrillation of flutter was recorded. In patients with VT ablation was delivered in the right ventricle (160 J, 9 patients) or in the left ventricle (240 J, 16 patients). The effects of ablation could only be interpreted in 21 patients who underwent 25 ablations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Indications and prospects of cardiac fulguration].

Fulguration is a new technique of palliative treatment (ablation or alteration of the atrioventricular junction) of refractory supraventricular tachycardias. It can be too a curative treatment of arrhythmias unresponsive to medial therapy and not suitable for surgery or implantable defibrillator (ventricular tachycardias - refractory arrhythmias of the Wolff-Parkinson-White Syndrome and permanent or incessant form of reciprocating tachycardia). An original indication of this method is the ablation of the retrograde pathway alone in refractory intranodal reciprocating tachycardias. The results of these indications are herein analysed.

Aged↗

[Catheter ablation after the direct electrical recording of the bundle of Kent. Apropos of 3 cases].

The success rate of catheter ablation, the latest therapeutic method in the treatment of cardiac arrhythmias, varies according to the precise indication. The best and most logical guarantee of its efficacy is the application of the electrical energy at an anatomical site essential to the arrhythmia. In preexcitation syndromes this site is without doubt the accessory pathway itself rather than its insertions, but this implies the recording of its activation. We recorded the electrical activation of a right sided Kent bundle in three consecutive cases to guide the therapeutic procedure (comparable to the recording of the H potential for his bundle ablation). All patients had paroxysmal atrial fibrillation (minimal RR interval: 175, 150 and 200 ms) and orthodromic reciprocating tachycardia. Two patients had had attacks of ventricular fibrillation. The sites of the Kent bundles were posteroseptal in 2 cases and anterolateral in 1 case. The recording of the electrical activation of the Kent bundle was validated by: the passage (induced or spontaneous) of a preexcited to a normal QRS coincident with the disappearance of the K potential; the exclusion of an atrial or ventricular origin of the electrical activation supposed to be the activation of the Kent bundle; electrical stimulation at the site of the recording of the K potential leading to prolongation of the stimulus-delta wave interval from 10 to 35 ms, with QRS morphology identical to the spontaneous complexes. All 3 patients were clinically cured by catheter ablation at the site of recording of the Kent bundle activation with follow-up periods ranging from 10 to 16 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Oral propafenone in refractory arrhythmia. Apropos of 68 patients].

68 patients with rhythmical disorders unresponsive to treatment with one or several antiarrhythmics (quinidine derivatives 52 patients, amiodarone 28 patients, beta-blockers 24 patients) were treated by mouth with propafenone, with a mean postponement of 5.6 +/- 8.5 months (1 day to 33 months). Auricular arrhythmia was observed in 41 patients with the following results: 16 successes among the 24 patients with paroxysmal fibrillation of flutter, 3 successes among the 8 patients with an arrhythmia reduced by cardioversion, and 3 successes among the 9 patients with auricular tachycardia, including 6 systolic tachycardias. Of 8 patients with an intranodal reciprocal rhythm, 7 were treated successfully with propafenone, which acts on the retrograde part of the cycle. Successes were also recorded in 2 out of 3 patients with Wolff-Parkinson-White syndrome. In 19 cases of ventricular tachycardia, propafenone proved to be efficacious in 3 out of 5 cases presenting rapid discharges and in 7 out of 14 patients with continuous arrhythmias, notably those with a catecholaminergic component. Side-effects were digestive (5 patients), cardiac decompensation (3 patients), asthenia and asthma (1 patient) and the transformation of a flutter from 2/1 to 1/1 (1 patient).

Administration, Oral↗

[Arrhythmia in relation to acute alcoholic intoxication in the absence of obvious cardiopathy].

Following acute intoxication with alcohol, 8 patients developed 16 episodes of arrhythmia, including 15 supraventricular tachycardias and one torsade de pointe. Seven of the 8 patients were chronically abusing of alcoholic drinks. None of the patients had clinically obvious cardiac pathology nor echocardiographic evidence of myocardiopathy. In 7 of them, however, baseline electrocardiograms disclosed disorders of intra-atrial conduction. The role of the different factors which might determine the occurrence of arrhythmia (notably alcohol, the autonomic nervous system, associated metabolic abnormalities and absorption of medicines) is discussed.

Adult↗