Biomedical subjects

P Attuel

Publications and source records attributed to P Attuel.

At least 19 recordsLinked to original sources

PubMed2004

[Hypertension and age over 70 years are the two most important risk factors for stroke in patients with atrial fibrillation].

In a registry of 250 patients treated for atrial fibrillation (160 recurrent, 90 permanent forms), we prospectively looked for associated risk factors for cerebrovascular complications. After a 4-years follow-up, 19 patients had presented a cerebral accident (13 strokes, 4 transient ischemic attacks, 2 cerebral hemorrhages). Prognostic factors for cerebrovascular complications were hypertension, valvular heart disease, and age > or = 70 years. When restricting the analysis to stroke and transient ischemic attacks, prognostic factors were limited to hypertension and age > or = 70 years. In conclusion, hypertension and age > or = 70 years are the main independent risk factors for cerebral ischemic attacks in out-of-hospital patients treated for atrial fibrillation.

Age Factors↗

PubMed2003

[Atrial vulnerability: a new protocol by bigeminy pacing].

INTRODUCTION: There is little information available on the events that mediate short term remodeling. In a bigeminy atrial-pacing protocol, we sought to evaluate the electrophysiological consequences of an irregular short-long cycle length atrial pacing. METHODS AND RESULTS: This study included 22 consecutive patients with documented arrhythmias and 10 control subjects. After evaluating the effective and functional refractory periods, bigeminy atrial pacing was performed for 5 min. During bigeminy pacing, in 12 AF patients and in none of the control subjects, AF was started lasting longer than 1 minute (Group I). Short salvos of AF occurred in five patients and three controls (Group II) and no arrhythmia occurred in five patients and seven controls (Group III). Sensitivity, specificity, negative and positive predictive values of sustained AF induced by bigeminy pacing were 54%, 100%, 50% and 100%, respectively. Atrial refractory periods measured immediately after termination of 5 minutes of bigeminy pacing were shorter than during baseline. The degree of shortening was similar in AF patients and in controls. The loco-regional conduction did not change after the bigeminy protocol. CONCLUSION: This study demonstrates that atrial bigeminy pacing unmasks latent atrial vulnerability.

Atrial Fibrillation↗

PubMed2001

[Holter monitoring in 2000].

Ambulatory 24 hour monitoring was developed in the United States and bears the name of its inventor, Holter. It was introduced in France for the first time by the Lariboisière school, 25 years ago, and the end of the year 2000 is an appropriate time to review this tool. What are the new clinical indications, technical progress and prospects for the future? All the efforts of both cardiologists and engineers for the past 25 years have been focused on gathering information about the system of cardiac regulation which is more or less concealed in the ECG recordings. As far as arrhythmias are concerned, or the QRS or T wave morphology, or the circadian variations of sinus rate and depolarisation, the studies are numerous but not always easily applicable in clinical practice. However, the non-invasive analysis given by the Holter recording guarantees a promising future in terms of new discoveries and applications.

Arrhythmias, Cardiac↗

PubMed2000

Electrophysiological determinants of atrial fibrillation in sinus node dysfunction despite atrial pacing.

AIMS: The effectiveness of atrial pacing in reducing the incidence of atrial fibrillation in patients with sinus node dysfunction is incomplete, and the correlation between electrophysiological atrial properties and the effect of permanent atrial pacing has been poorly investigated. Accordingly, the aim of the present study was to correlate electrophysiological data, in terms of atrial refractoriness, conduction parameters, and propensity to atrial fibrillation induction, and the likelihood of atrial fibrillation after DDD device implantation. METHODS AND RESULTS: The authors reviewed electrophysiological data of 41 patients with sinus node dysfunction (mean age 70 +/- 8 years, who were investigated free of anti-arrhythmic treatments before pacemaker implantation. At a drive cycle length of 600 ms, effective and functional refractory periods, S1-A1 and S2-A2 latency, A1 and A2 width, and latent vulnerability index (effective refractory period [ERP] A2), were measured. Atrial fibrillation induction was tested with up to three extrastimuli in 34 patients. Induction of sustained atrial fibrillation (> 1 min) was considered as the end-point. P-wave duration on the surface ECG in lead II/V1 was also measured. Minimal atrial rate was programmed between 60 and 75 bpm (mean: 64 +/- 4 bpm). After implantation, the patients were followed-up for 28 +/- 17 months, and ECG-documented occurrence of atrial fibrillation was determined. Electrophysiological characteristics of patients with (n = 12) or without (n = 29) paroxysmal atrial fibrillation before implantation were similar. When comparing patients with (n = 11) or without (n = 30) post-pacing atrial fibrillation occurrence, no differences were found in age, underlying heart disease, left atrial size, minimal pacing rate, and follow-up duration. Additionally, between the two former groups, there was no significant difference in terms of effective refractory periods (233 +/- 47 ms vs 239 +/- 25 ms), functional refractory periods (280 +/- 48 ms vs 272 +/- 21 ms), S1-A1 (44 +/- 20 ms vs 37 +/- 13 ms) and S2-A2 latency (77 +/- 28 ms vs 66 +/- 22 ms), and A1 duration (60 +/- 23 ms vs 53 +/- 16 ms). In contrast, in patients with post-pacing atrial fibrillation occurrence, the P wave was more prolonged (116 +/- 22 ms vs 98 +/- 13 ms; P < 0.01), A2 was longer (116 +/- 41 ms vs 87 +/- 27 ms; P < 0.01), effective refractory periods/A2 was lower (2.1 +/- 0.4 cm vs 3.1 +/- 1.4 cm; P < 0.05), and rate of atrial fibrillation induction was higher (8/11 patients vs 8/23 patients; P < 0.05). Electrophysiological characteristics of patients free of post-pacing atrial fibrillation with associated (n = 6) or unassociated (n = 24) paroxysmal atrial fibrillation history before implantation were quite similar. In patients with post-pacing atrial fibrillation with associated (n = 6) or unassociated atrial fibrillation history (n = 5) before implantation, effective refractory periods was statistically different (207 +/- 23 ms vs 264 +/- 46 ms; P < 0.05). Values of effective refractory periods < 220 ms were significantly more frequent in patients with post-pacing atrial fibrillation than in patients without (4/11 patients vs 2/30 patients; P < 0.05). When comparing patients with post-pacing atrial fibrillation with effective refractory periods > or = 220 ms (n = 7) and < 220 ms (n = 4), A2 duration was remarkably prolonged (145 +/- 42 ms vs 90 +/- 11 ms; P < 0.05) in those with effective refractory periods > or = 220 ms. By contrast, between the two groups, effective refractory periods/A2 were identical (2.08 +/- 0.6 cm vs 2.15 +/- 0.3 cm; P = n.s.). CONCLUSION: Prolonged atrial refractoriness, lesser degrees of conduction disturbance and a lower rate of atrial fibrillation induction seem to be predictive of stable sinus rhythm. In contrast, patients with persistence of atrial fibrillation despite pacing have a more abnormal and inhomogeneous atrial substrate, as well as a higher rate of atrial fibrillation induction. Prolonged P wave, shortened refractoriness, or remarkably abnormal conduction disturbances in the presence of prolonged refractoriness limit the effectiveness of standard atrial pacing in atrial fibrillation prevention. Identification of predictive criteria of failure of single-site atrial pacing may be used to consider dual-site atrial pacing in such patients with sinus node dysfunction.

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PubMed2000

Is dual site better than single site atrial pacing in the prevention of atrial fibrillation?

Long-term prevention of atrial fibrillation is not constantly realized by single-site right atrial pacing, and the beneficial role of multisite atrial pacing is still being studied. Accordingly, we compared the effectiveness of dual site and single site atrial pacing in 83 patients (50 men, 33 women, aged 69 +/- 10 years), who received a DDD device for primary sinus node dysfunction or bradycardia with documented atrial fibrillation. Inclusion criteria for dual site pacing were a sinus P wave > or = 120 ms and at least two episodes of documented paroxysmal AF in the 6 months preceding implantation. Dual site atrial pacing (high right atrium-coronary sinus ostium) was performed in 30 cases, and was compared to 53 single site paced patients, 21 with a P wave > or = 120 ms and 32 with a P wave < 120 ms. The basic pacing rate was programmed at 68 +/- 4 beats/min (range 60-75 beats/min). Sinus P wave (133 +/- 20 vs 95 +/- 9 ms; P < 0.001), paced P wave (107 +/- 14 vs 99 +/- 15; P < 0.05), number of antiarrhythmic drugs used (2.4 +/- 1.2 vs 1.6 +/- 1.5, P < 0.05), and the duration of symptoms (8.1 +/- 4.5 vs 3.8 +/- 2.4 years; P < 0.001) were significantly higher in dual site patients. The other characteristics were similar. During the follow-up of 18 +/- 15 months (range 3-30 months), paroxysmal AF was documented in 33 patients. Among these patients, 13 developed permanent AF following at least one episode of paroxysmal AF. When comparing dual site patients and single site patients with a P wave duration > or = 120 ms, paroxysmal AF incidence was lower in the dual site group (9/30 patients vs 15/21 patients, P < 0.01), as well as permanent AF (1/30 patients vs 8/21 patients, P < 0.01). By contrast, comparison between dual site patients and the group of single site patients with a P wave duration < 120 ms did not evidence any significant differences in paroxysmal (9/30 patients vs 9/32 patients) and permanent (1/30 patients vs 4/32 patients) AF incidences. Dual site seems better able than single site atrial pacing to improve the natural history of patients with a prolonged P wave, reducing the incidence of paroxysmal and permanent AF. No benefit could be expected in patients with a normal P wave duration.

Aged↗

PubMed2000

Electrophysiological characteristics of the atrium in sinus node dysfunction with and without postpacing atrial fibrillation.

In patients with sinus node dysfunction (SND) with or without associated paroxysmal atrial fibrillation (AF), the effectiveness of atrial pacing in reducing the incidence of AF is not definitive. In addition, despite several studies involving large populations of implanted patients, little attention has been paid to the electrophysiological (EP) atrial substrate and the effect of permanent atrial pacing. The aim of this study is to correlate EP data and the risk of AF after DDD device implantation. We reviewed EP data of 38 consecutive patients with SND, mean age 70 +/- 8 years, who were investigated free of antiarrhythmic treatment, for the evaluation of the atrial substrate. We also considered as control group 25 subjects, mean age 63 +/- 14 years, referred to our EP laboratory for unexplained syncope or various atrioventricular disturbances. Following pharmacological washout and at a drive cycle length of 600 ms, effective and functional refractory periods (ERP, FRP), S1-A1 and S2-A2 latency, A1 and A2 conduction duration, and latent vulnerability index (ERP/A2) were measured. AF induction was tested with up to three extrastimuli at paced cycle lengths of 600 and 400 ms in 20 patients. Induction of sustained AF (> 30 seconds) was considered as the endpoint. P wave duration on the surface ECG in lead II/V1 was also measured. DDD pacing mode was chosen in all patients with the minimal atrial rate programmed between 60 and 75 beats/min (mean 64 +/- 4 beats/min). After implantation, the patients were followed-up for 29 +/- 17 months and clinically documented occurrence of AF was determined. When comparing patients with SND and subjects of the control group, we did not find any significant statistical differences in terms of ERP (237 +/- 33 vs 250 +/- 29 ms), FRP (276 +/- 30 vs 280 +/- 32 ms) and S1-A1 (39 +/- 16 vs 33 +/- 11 ms) and S2-A2 latency (69 +/- 24 vs 63 +/- 25 ms). In contrast, we observed significant differences regarding A1 (55 +/- 19 vs 39 +/- 13 ms; P < 0.001), A2 (95 +/- 34 vs 57 +/- 18 ms; P < 0.001) and P wave duration (104 +/- 18 vs 94 +/- 15 ms; P < 0.05), and ERP/A2 (2.8 +/- 1.2 vs 4.8 +/- 1.6; P < 0.001). When comparing patients with (n = 11) or without (n = 27) postpacing AF occurrence, we did not find any difference with reference to ERP, FRP, S1-A1, S2-A2, A1 duration, or follow-up duration. In patients with postpacing AF occurrence, A2 was longer (116 +/- 41 vs 87 +/- 27 ms; P < 0.01), ERP/A2 lower (2.1 +/- 0.4 vs 3.1 +/- 1.4; P < 0.05), P wave more prolonged (116 +/- 22 vs 99 +/- 14 ms; P < 0.01), and preexisting AF history predominant (6/11 vs 5/27 patients; P < 0.05). No difference was observed between patients with (n = 8) and without (n = 12) AF induction during the EP study. In patients with SND, the atrial refractoriness appears normal and the most important abnormality concerns conduction slowing disturbances. Persistence of AF despite pacing stresses the importance of mechanisms responsible for AF not entirely brady-dependent. In this setting, more prolonged atrial conduction disturbances, responsible for a low vulnerability index, and a preexisting history of AF enable us to identify a high risk patient group for AF in the follow-up.

Adult↗

PubMed2000

Electrophysiologic characteristics of the atrium in sinus node dysfunction: atrial refractoriness and conduction.

INTRODUCTION: Clinical electrophysiology (EP) has focused attention on the EP properties of atrial muscle in patients with atrial fibrillation (AF). Patients with sinus node dysfunction (SND) sometimes are included in these studies, but the characteristics of these patients with SND alone appear less well investigated. METHODS AND RESULTS: We reviewed EP data of 46 patients (mean age 70 +/- 8 years) with SND, who underwent EP study for evaluation of the atrial substrate. In 16 patients, a history of paroxysmal AF was documented, but not in the remaining 30 patients who had SND alone. We considered as control a group of 25 subjects (mean age 63 +/- 14 years), who were referred to our EP laboratory for unexplained syncope or AV conduction disturbances. Following pharmacologic washout and at a drive cycle of 600 msec, effective (ERP) and functional refractory periods (FRP), S1-A1 and S2-A2 latency, A1 and A2 width, latent vulnerability index (ERP/A2), and P wave duration on the surface ECG were measured. Intra-atrial conduction times were measured from the stimulus artifact by pacing the high right atrium (HRA), to the corresponding atriograms at the AV node (HRA-AVN), low lateral atrium (HRA-LLA), and low interatrial septum close to the coronary sinus ostium (HRA-CSO). Compared with the control group, SND patients did not show differences in ERP (238 +/- 26 msec vs 250 +/- 29 msec), FRP (274 +/- 25 msec vs 280 +/- 32 msec), S1-A1 (38 +/- 15 msec vs 33 +/- 11 msec) and S2-A2 latency (67 +/- 24 msec vs 63 +/- 25 msec), or HRA-AVN (81 +/- 24 msec vs 65 +/- 19 msec), HRA-LLA (36 +/- 30 msec vs 40 +/- 27 msec), and HRA-CSO (77 +/- 17 msec vs 80 +/- 15 msec) conduction times. In contrast, we observed strong differences in atriogram durations A1 (59 +/- 19 msec vs 39 +/- 13 msec; P < 0.001) and A2 (92 +/- 28 msec vs 57 +/- 18 msec; P < 0.001), as well as in the latent vulnerability index ERP/A2 (2.8 +/- 1.2 msec vs 4.8 +/- 1.7; P < 0.001). Also, the P wave was slightly longer (104 +/- 18 msec vs 94 +/- 45 msec; P < 0.05). No significant statistical difference in EP parameters was found between SND patients with or without documented AF. CONCLUSION: In patients with SND, atrial refractoriness appears similar to that of control subjects. The most important EP abnormality appears to be local conduction slowing disturbances, with prolonged basal and postextrastimuli atriograms, responsible for a lower vulnerability index. This could explain, at least in part, the tendency of patients with SND to develop AF during their natural history. Normality of atrial refractoriness, in contrast to atrial conduction disorders, might explain why atrial pacing shows a preventative effect on the development of AF and why antiarrhythmic drugs often are ineffective.

Aged↗

PubMed1999

Sick sinus syndrome with and without atrial fibrillation: atrial refractoriness and conduction characteristics.

BACKGROUND: Clinical electrophysiology has focused the attention on the electrophysiological properties of the atrial muscle in patients with atrial fibrillation: shortened and inhomogeneous refractoriness and local and regional conduction slowing, as well as prolonged intra- and interatrial conduction disturbances, are well described as electrophysiological parameters associated with the genesis of atrial fibrillation. Patients with sick sinus syndrome are variously included in these studies, but electrophysiological characteristics of patients with sick sinus syndrome alone appear less investigated, even if atrial fibrillation is part of its natural history. The aim of the present study was to define the electrophysiological characteristics of sick sinus syndrome patients with or without paroxysmal atrial fibrillation, compared to subjects without atrial fibrillation and sick sinus syndrome. METHODS: We reviewed the electrophysiological data of 39 patients with sick sinus syndrome (mean age 70 +/- 8 years), who underwent an electrophysiological study in sinus rhythm for the evaluation of the atrial substrate. In 12 patients an associated history of paroxysmal atrial fibrillation was documented. Twenty-seven patients were included in the study with a diagnosis of sinus node dysfunction alone. We also considered as control group 25 subjects (mean age 63 +/- 14 years), referred to our electrophysiological laboratory for unexplained syncope or atrioventricular disturbances. Following pharmacological wash-out and at a drive cycle of 600 ms, effective and functional refractory periods, S1-A1 and S2-A2 latency, A1 and A2 width, and the latent vulnerability index (effective refractory period/A2), were measured. In addition, the P-wave duration during spontaneous sinus rhythm on the surface ECG in D II/V1 leads was measured. RESULTS: Between sick sinus syndrome patients with or without atrial fibrillation, no significant statistical differences in electrophysiological parameters were found. When compared to the control group, sick sinus syndrome patients did not show any differences in effective refractory period (239 +/- 34 vs 250 +/- 29 ms), functional refractory period (276 +/- 28 vs 280 +/- 32 ms), S1-A1 (38 +/- 16 vs 33 +/- 11 ms), and S2-A2 latency (68 +/- 25 vs 63 +/- 25 ms). In contrast, we observed remarkable differences in terms of atriogram duration A1 (60 +/- 20 vs 39 +/- 13 ms, p < 0.001), A2 (95 +/- 34 vs 57 +/- 18 ms, p < 0.001), and effective refractory period/A2 (2.8 +/- 1.2 vs 4.8 +/- 1.7 cm, p < 0.001). Also the duration of the P wave was longer (103 +/- 17 vs 94 +/- 45 ms, p < 0.05). CONCLUSIONS: In sick sinus syndrome patients with or without atrial fibrillation, electrophysiological characteristics appear homogeneous. When compared to the control group, refractoriness was quite similar. In contrast, the most important abnormalities appear based on conduction slowing disturbances, responsible for a low latent vulnerability index. This could explain, at least in part, the tendency of sick sinus syndrome to develop atrial fibrillation as a part of its natural history. At present, the influence of an altered electrophysiological substrate on pharmacological or pacing therapy in patients with sick sinus syndrome is not yet known.

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PubMed1998

[The effects of the ablation of atrial flutter in patients with and without a clinical history of paroxysmal atrial fibrillation].

BACKGROUND: Although the safety and effectiveness of radiofrequency (RF) transcatheter ablation in patients with atrial flutter (AFL) is well established, little attention is paid to previous history of associated paroxysmal atrial fibrillation (AF) and the recurrence of AFL after RF ablation. In addition, it is not known whether the elimination of AFL can modify the natural history of AF in patients who experience both of these arrhythmias. Accordingly, the aim of this study was to evaluate the effect of RF ablation of AFL in patients with or without a previous history of AF in terms of the incidence of both arrhythmias in the follow-up. METHODS: RF ablation of the atrial isthmus between tricuspid ring, coronary sinus os and inferior vena cava was performed in 27 patients (23 males, 4 females; mean age 61 +/- 9 years) according to the technique described by Cosio. Based on ECG pattern, twenty patients exhibited common or type 1 AFL (negative F waves in the inferior leads with a sawtooth morphology), while seven patients had both common and uncommon AFL (various surface F wave morphologies, generally positive F waves in the inferior leads). A history of association between AFL and paroxysmal AF was documented in 48% of patients, but AFL was the major arrhythmia. After ablation, the patients were followed up and the clinically documented occurrence of arrhythmias was determined. RESULTS: Based on clinical history before ablation, we compared patients with an association between AFL and AF (Gr AFL + AF; n = 13) vs patients with only AFL (Gr AFL; n = 14). The characteristics of the two groups were similar regarding age, sex, duration of symptom, structural heart disease, left atrial size, P-wave duration, AFL interruption during RF procedure, antiarrhythmic treatment before and after RF procedure, and duration of follow-up. During a follow-up of 12 +/- 6 months, AFL recurred in 10 patients (37%), 4 from Gr AFL + AF, and 6 from Gr AFL (p = NS). Episodes of paroxysmal AF occurred in 6 patients (22%), 5 from Gr AFL + AF and 1 from Gr AFL (p < 0.05). In Gr AFL + AF, the incidence of AF after ablation was significantly lower (1.8 +/- 0.6 vs. 0.7 +/- 1 episodes/year; p < 0.02). Characteristics of patients with or without AFL recurrence in the follow-up were similar. The percentage of patients with the occurrence of AFL or AF, associated or unassociated in the follow-up, was 55%. CONCLUSIONS: A history of paroxysmal AF before RF ablation of AFL is not predictive of long-term success or failure of the procedure when considering the recurrence of AFL alone. Nevertheless, the general results are disappointing because the majority of patients have arrhythmias, AFL or AF, associated or unassociated in the follow-up. A clinical history of AF before ablation is correlated with a higher incidence of AF in the follow-up. In any event, the incidence of AF episodes is lower in the follow-up, indicating a possible beneficial effect of AFL ablation on AF mechanisms.

Adult↗

PubMed1997

Direct-current cardioversion of atrial tachyarrhythmias under oral flecainide therapy.

Results of direct-current cardioversion of 48 patients with atrial arrhythmia taking oral flecainide were compared with those of 96 control-matched patients. After completion of 3 shocks, 98% of flecainide patients were converted versus 78% of control patients (p <0.01). Thus, despite an experimental increase in defibrillation threshold, flecainide given before cardioversion seems to have a beneficial effect.

Administration, Oral↗

PubMed1995

[Nosology of atrial fibrillation. Attempt at clarification].

Atrial fibrillation is the subject of much clinical interest as it is the arrhythmia responsible for the greatest number of hospital admissions. The arrhythmia working group of the French Society of Cardiology held a symposium on atrial fibrillation in order to establish certain definitions and to assess the value of a classification of atrial fibrillation. This was also the occasion to review a number of known facts and points which remain obscure, concerning this common arrhythmia. A therapeutic strategy is proposed.

Age Factors↗

PubMed1994

[Value of electrophysiological studies in the evaluation of atrial fibrillation].

Electrophysiological studies of the atrium provide a means of evaluating the parameter involved in the process of fibrillation. The study of atrial vulnerability, initially limited to the test of provocation of the arrhythmia, has widened to include analysis of the substrate. Shortened refractory periods and regional conduction defects play a role in the creation of reentry pathways. Variations in the heart rate influence these parameters and explain the fundamental role of the autonomic nervous system on the uniformity of the activation front. The risk of atrial fibrillation is related essentially to thrombo-embolism: atrial vulnerability was investigated in 70 patients with unexplained cerebrovascular accidents. Globally, one out of two patients had pathological substrates. This study of atrial vulnerability showed that it was possible to identify a group of patients at risk of atrial fibrillation, even before the arrhythmia was recorded. This prognostic approach could also be applied to the investigation of preexcitation and syncope, and to the evaluation of the effects of pharmacological intervention.

Atrial Fibrillation↗

PubMed1993

[Paroxysmal atrial fibrillation].

Paroxysmal atrial fibrillation is the most frequent of cardiac arrhythmias and its frequency increases with age. Its diagnosis is difficult since the symptoms are often absent or misleading. It is based on electrocardiogram performed during the attack, and this has been made easier by the Holter technique or by sequential recordings triggered by the patient himself. It is only in special cases, when percritical recordings could not be made that intracavitary electrophysiological study is used to obtain indirect arguments in favour of the diagnosis. All heart diseases can be attended by this cardiac rhythm disorder which usually marks an unfavourable turn in the course of the disease, with an increased risk of sudden death in the end. But in most cases the only disorder found is a common arterial hypertension. Atrial fibrillation carries a risk of peripheral, and in particular cerebral, embolism evaluated at 5% per annum. This risk is high in patients with cardiopathy, but it also exists even with a normal heart. The value of anticoagulants has been demonstrated by large controlled studies, but it is important to know that a very strong anticoagulant treatment is unnecessary to reduce the risk of embolism. Only antiarrhythmic agents can maintain the patients in sinus rhythm for as long as possible before the passage to permanent fibrillation. Although no beneficial effect on mortality has been proved, these drugs are indicated for patients who have very marked symptoms or a major cardiopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Fibrillation↗

PubMed1991

[Atrial electrophysiological study of unexplained cerebrovascular disorders].

The aim of this study was to detect possible atrial electrophysiological abnormalities in patients with unexplained embolic cerebrovascular accidents without overt atrial arrhythmias. This group was compared with normal controls and a group of patients with paroxysmal atrial fibrillation. Sixty-six patients were studied: Group I normal controls (N = 20); Group II patients with CVA (N = 26) and Group III, patients with paroxysmal atrial fibrillation (N = 20). Each group was divided into 2 subgroups according to age (over and under 45 years). The following parameters were taken into consideration: parameters correlated to atrial excitability (effective and functional refractory periods, adaptation of these refractory periods, intraatrial conduction--A1 and A2, S1A1, S2A2 intervals--, index of latent vulnerability); provocative testing by the extrastimulus technique; classical indices of atrioventricular conduction and sinus node function. In subjects over 45 years of age, the effective refractory periods were shorter in Group III (214 +/- 33 ms) and II (214 +/- 32 ms) than in the control Group I (248 +/- 21 ms), p less than 0.01. This difference was not apparent in younger patients. Inadaptation of the refractory periods was demonstrated equally in Groups II and III in all ages whilst the control subjects showed normal adaptation, p less than 0.05. Intraatrial A1 and especially A2 conduction was significantly prolonged in Group III (94.5 +/- 24 ms) and II (87 +/- 14 ms) compared with the control group (69 +/- 8 ms), p less than 0.01, especially in younger subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

[The autonomic nervous system in sudden infant death syndrome. Analysis of heart rate and sinusal variability on Holter monitoring of infants who died].

To evidence abnormality of cardiac control by the autonomic nervous system in the sudden infant death syndrome (SIDS) we retrospectively analysed the Holter recordings and cardiopneumograms of 19 infants (11 boys, 8 girls) of mean +/- SD age 2.3 +/- 1.5 months who had subsequently died of SIDS. Two infants were regarded as normal and the reference diagnoses in the remaining 17 infants were: apparent life threatening event (8), SIDS siblings (8) and prematurity (1). At the time of death the age was 4.2 +/- 2 months. Each of these infants was matched with three control infants in term of postnatal age, gestational age and reference diagnosis, but without SIDS at follow-up of at least one year. Nine hours of Holter recordings (9 p.m. to 6 a.m.) were analysed in term of mean heart rate and sinus oscillations waves. To differentiate between short oscillations of 4 to 6 RR, which are induced by respiration and reflect vagal activity, and long oscillations of 20 to 32 RR, which reflect both neurogenic sympathetic and vagal activity, we used a new method which measures the number and the amplitude in milliseconds of each type of oscillations. The results are expressed as the logarithm of the product of these two variables. Heart rate, correlated to age in both groups, is higher in the deceased infants group (141 +/- 14 mn and 135 +/- 15; p less than 0.05: analysis of covariance with age as an independent variable). Short oscillations, also correlated to age, are lower in the deceased infants group (3.35 +/- 0.59 and 3.65 +/- 0.61; p less than 0.05: analysis of covariance with age).(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmia, Sinus↗

PubMed1988

Long-term follow-up of atrioventricular junctional transcatheter electrical ablation.

Complete data concerning long-term results of transcatheter electrical ablation of the atrioventricular junction is not available. At the request of the French Cardiac Arrhythmia Working group we undertook an inquiry in October 1983. All centers potentially able to perform such procedures were asked to report their experience. Eight centers have performed one case or more, over a period of 3 years, for a total of 91 patients. The mean follow-up completed in all patients in April 1986 was 12 +/- 10 months. The procedure was indicated for a supraventricular arrhythmia resistant to a mean of 3.9 +/- 1.3 classes of antiarrhythmic agents. Atrial flutter or fibrillation in 54 (59%) and atrioventricular nodal reentry in 17 (18%) were the most common arrhythmias. A mean of 2.6 +/- 2.3 electrical shocks (range 1-14 shocks) with a stored energy of 130-400 joules was delivered during 1-5 sessions. Complete heart block was obtained in 83 patients and persisted at the time of discharge from the hospital in 46 patients (50.5%). The immediate complication (within 24 hours after the procedure) included ventricular fibrillation successfully converted (one patient) and nonsustained ventricular tachycardia (three patients). Late complications included one death 3 days after the procedure, in a patient in whom sustained ventricular tachycardia was documented, nonsustained ventricular tachycardia in two patients, sepsis in three patients and pericardial effusion in one patient. At the time of the follow-up, there were three additional deaths related to sepsis due to pacemaker pocket infection in one patient and to preexisting congestive heart failure in two patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1988

DDD pacing: an effective treatment modality for recurrent atrial arrhythmias.

We performed atrial EP studies (atrial substrate evaluation) on 10 patients. These patients had evidence of paroxysmal, sustained, recurrent atrial arrhythmias (7 men and 3 women with a mean age of 64 +/- 15 years). All patients combined a brady-tachy syndrome; 7 patients had a sick sinus syndrome (SSS) and 3 patients a typical vagally induced atrial arrhythmia. No anti-arrhythmic drug was allowed in 3 patients with SSS, 1 drug failed in 4 patients and the combination of 2 drugs failed in 3 patients during the first to eighth years prior to pacemaker implantation. Atrial substrate evaluation was feasible in all these patients off anti-arrhythmic therapy and showed important abnormalities of atrial loco-regional conduction parameters and long refractory periods (RP). The remarkable point was, in 7 patients, a paradoxical improvement in intra-atrial conduction delay at rapid pacing rate. The DDD pacing mode was chosen in all patients. No technical problem occurred during implantation. Atrial pacing rate was programmed to be slightly higher than the mean diurnal heart rate calculated on Holter monitoring. After implantation, the mean follow-up period was 18 +/- 25 months with an average of one Holter every 4 months during the first 2 years. The 7 patients who improved intra-atrial conduction at rapid pacing rate were controlled without drugs, 2 patients were controlled with 1 drug, and 1 patient with 2 drugs. Atrial pacing in the DDD mode in a selected group of patients prevents paroxysmal and drug-resistant atrial arrhythmias. Atrial substrate evaluation is a sensitive tool for assuring the long-term benefit of atrial pacing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1986

Importance of atrial electrophysiology in the work-up of cerebral ischemic attacks.

Recent data suggest that a large proportion of ischemic strokes are due to embolic phenomena from the heart. Atrial fibrillation appears to be one of the principal causes of embolization. If electrophysiologic parameters are considered as determining factors, the existence of atrial hypervulnerability in patients with embolic strokes is significant, when arrhythmia has been excluded as an etiology. This study suggests that an aggressive approach to early diagnosis and management through electrophysiologic studies might aid in preventing future neurologic attacks.

Adult↗