Effectiveness of irrigated tip catheter ablation of common atrial flutter.
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Aged↗
Biomedical subjects
P Le Métayer
Publications and source records attributed to P Le Métayer.
Validation by serial standardized testing of a new rate-responsive pacemaker sensor based on variations in myocardial contractility.
AIMS: Preliminary studies have shown that peak endocardial acceleration (PEA), measured by a micro-accelerometer at the right ventricular apex, is highly correlated with left ventricular contractility (dp/dt max). Furthermore, changes in PEA are closely correlated with sinus node rate changes during exercise and during pharmacological interventions. Peak endocardial acceleration has, therefore, been used to drive a rate-responsive DDD pacemaker. This study compared the chronotropic performance of such devices implanted in 14 patients suffering from chronotropic incompetence with that observed in 18 control subjects in normal sinus rhythm. METHODS AND RESULTS: Five standardized daily life activities (hall walk, climbing up and down stairs, squatting and hyperventilation) and two types of exercise (Bruce treadmill protocol and bicycle ergometry) were performed in a random order after individual programming of each pacemaker. For each test, a correlation coefficient was calculated between changes in PEA and variations in paced rate, between instantaneous variations in heart rate monitored by telemetry and continuous measurement of heart rate by the pacemaker, and between sensor-driven rate in patients and normal sinus rhythm in controls. The variations in paced heart rate were closely correlated with those observed in subjects with normal sinus rhythm, and proved to be sensitive, specific, rapid and independent of the type of exercise. After optimal programming of the sensor, PEA modulates the heart rate as expected during normal sinus rhythm. CONCLUSIONS: In this study, a single PEA sensor successfully restored chronotropic response in a population of paced patients with severe chronotropic incompetence. Peak endocardial acceleration can be monitored on a beat-to-beat basis, in parallel with heart rate, and the pacemaker can be accurately programmed with a single exercise test.
Aged↗
Clinical prediction of lower limb deep vein thrombosis in symptomatic hospitalized patients.
We evaluated two clinical scores for the prediction of deep venous thrombosis (DVT) in hospitalized patients (Wells' and Kahn's). We included 273 patients referred to the vascular exploration unit for the suspicion of DVT. A clinical questionnaire was tilled in by the practitioner and the scores were calculated from this form. 66 of the 273 patients had a DVT. When Wells' score was 3, a DVT was found by duplex echography in 51% patients; when the score was 0, a DVT was found in 9%. Kahn's score was not adapted to this population. We then developed a new simple score (cancer, palsy or plaster immobilization, warmth, superficial venous dilation, unilateral pitting edema, other diagnosis). A DVT was found in 76% patients with a score of 3 and in 11% in those with a score of 0. We therefore propose a 6-item score whose main advantages are simplicity and usefulness in routine practice.
Female↗
Mapping and ablation of left atrial flutters.
BACKGROUND: Typical right atrial isthmus-dependent flutters have been described in detail, but very little is known about left atrial (LA) flutters. METHODS AND RESULTS: We performed conventional and 3D mapping of the LA for 22 patients with atypical flutters. Complete maps in 17 patients demonstrated macroreentrant circuits (n=15) with 1 to 3 loops rotating around the mitral annulus, the pulmonary veins, and a zone of block or a silent area. In 2 patients, a small reentry circuit with a zone of markedly slow conduction was identified. Linear ablation performed across the most accessible part of the circuit cured 16 patients (73%) with a follow-up of 15+/-7 months. CONCLUSIONS: LA reentrant tachycardias are related to individually varying circuits and are amenable to mapping guided radiofrequency ablation.
Adult↗
[Auricular fibrillation. Diagnosis, complications, treatment].
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Anti-Arrhythmia Agents↗
[Clinicobiological study of 100 symptomatic patients with factor V Leiden mutation].
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Adult↗
Efficacy and safety of septal and left-atrial linear ablation for atrial fibrillation.
Atrial fibrillation (AF), the most common of all sustained cardiac arrhythmias, is frequently resistant to antiarrhythmic drugs, and physicians have seen limited success with catheter ablation limited to the right atrium. As a result, the safety and efficacy of systematic biatrial linear ablation for drug resistant AF was investigated. Forty-four patients (54 +/- 7 years) underwent catheter ablation of daily drug-resistant AF. Two right-atrial lines (1 septal and 1 cavotricuspid) and 3-4 left-atrial lines were transseptally performed: 2 joining each superior pulmonary vein to the posterior mitral annulus and 1 interconnecting them. An additional left-atrial septal line from the right superior pulmonary vein (RSPV) to the foramen ovalis was performed in 23 patients. Radiofrequency was delivered with a conventional thermocouple-equipped ablation catheter or with an irrigated tip ablation catheter for resistant cases and for sparing the endocardium. Of the 44 patients, 25 (57%) were successfully treated without antiarrhythmic drugs. Twelve patients (27%) improved (<6 hours of AF per trimester under a previously ineffective drug) and 7 (16%) were considered treatment failures. Multiple sessions were required to ablate new left-atrial macro-reentry and initiating foci (2.7 +/- 1.3 procedures per patient). Five patients had a pericardial effusion and 1 each a pulmonary embolism, an inferior myocardial infarction, and a reversible cerebral ischemic event. One patient had thrombosis of the 2 left pulmonary veins. Despite a relatively high success rate, this procedure is too long, and the safely and efficacy need to be improved and applied to a broader range of patients.
Adult↗
Clinical significance of multiple sensor options: rate response optimization, sensor blending, and trending.
The gold standard for rate modulation is the sinus node. To improve the rate modulation provided by artificial sensors, new sensors have to be developed or 2 different sensor systems can be combined within a single device. Association combination of a sensor with a rapid-response fast-rate increase sensor (activity) and a progressive, more specific sensor (QT ventilation) is generally used. Sensor combinations require adequate sensor blending for signal production and prioritization during rate modulation. However, in the new devices, some other aspects of rate modulation could be taken into consideration, particularly circadian rate variations to obtain lower rates at nighttime than during daytime, and automatic adaptation of the slope of rate increase during exercise, according to the patient's fitness, heart function, age, etc. Despite the need for automaticity, manual programming could continue to be useful to adapt rate modulation with data from sensor trending memories.
Circadian Rhythm↗
[Hemorrhagic complications of antivitamin K. Report of 75 hospitalized patients].
Hemorrhagic complications are the most frequent complications of antivitamin K (AVK) treatments and can be life-threatening. We report 75 patients from a University Hospital. They were 40 males and 35 females (median age 74 years, 20-94), and were classified into 3 grades according to clinical picture: grade 1 (no surgery or transfusion, grade 2: surgery or blood transfusion needed, grade 3: death). 43 patients had grade 1 complications, 27 grade 2, and 5 grade 3 complications. The most frequent complications were muscular hematomas (36 patients), sub-cutaneous hematomas (14 patients), digestive bleeding (13 patients), hematuria (12 subjects). Eight patients had intracerebral bleeding, of whom 3 died. The treatment time was very variable (1 to 988 weeks). Only half patients had a prothrombin rate (PR) below 20% but two thirds had an INR above 5. This study showed that PR was a poor predictor of hemorrhagic complications. INR was a better parameter. For 15 patients, we considered that the indication was unadapted or questionable, among whom 2 died. This work suggests that the promotion of AVK prescription rules should go on.
Adult↗
Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins.
BACKGROUND: Atrial fibrillation, the most common sustained cardiac arrhythmia and a major cause of stroke, results from simultaneous reentrant wavelets. Its spontaneous initiation has not been studied. METHODS: We studied 45 patients with frequent episodes of atrial fibrillation (mean [+/-SD] duration, 344+/-326 minutes per 24 hours) refractory to drug therapy. The spontaneous initiation of atrial fibrillation was mapped with the use of multielectrode catheters designed to record the earliest electrical activity preceding the onset of atrial fibrillation and associated atrial ectopic beats. The accuracy of the mapping was confirmed by the abrupt disappearance of triggering atrial ectopic beats after ablation with local radio-frequency energy. RESULTS: A single point of origin of atrial ectopic beats was identified in 29 patients, two points of origin were identified in 9 patients, and three or four points of origin were identified in 7 patients, for a total of 69 ectopic foci. Three foci were in the right atrium, 1 in the posterior left atrium, and 65 (94 percent) in the pulmonary veins (31 in the left superior, 17 in the right superior, 11 in the left inferior, and 6 in the right inferior pulmonary vein). The earliest activation was found to have occurred 2 to 4 cm inside the veins, marked by a local depolarization preceding the atrial ectopic beats on the surface electrocardiogram by 106+/-24 msec. Atrial fibrillation was initiated by a sudden burst of rapid depolarizations (340 per minute). A local depolarization could also be recognized during sinus rhythm and abolished by radiofrequency ablation. During a follow-up period of 8+/-6 months after ablation, 28 patients (62 percent) had no recurrence of atrial fibrillation. CONCLUSIONS: The pulmonary veins are an important source of ectopic beats, initiating frequent paroxysms of atrial fibrillation. These foci respond to treatment with radio-frequency ablation.
Adolescent↗
[Thrombosis of the inferior vena caval and right atrium in amoebic abscess of the liver].
Amoebic abscess of the liver is sometimes complicated by deep venous thrombosis but extension to the right atrium is rarely observed. The authors report the case of inferior vena caval thrombosis extending to the right atrium in a case of amoebic hepatic abscess. The patient was treated initially by antibiotherapy with metronidazole associated with intravenous anticoagulation. Rapid extension of the thrombus despite this treatment led to the initiation of thrombolysis. There were no embolic complications and the outcome was good. Apart from the rarity of this complication, this case poses the problem of the management of these patients. No previous reports of the use of thrombolysis were found in the medical literature. In the light of previous publications and the present case, the authors suggest investigation by CT scanning, echocardiography and venous Doppler ultrasonography in all cases of hepatic amoebic abscess.
Adult↗
Right and left atrial radiofrequency catheter therapy of paroxysmal atrial fibrillation.
INTRODUCTION: Atrial fibrillation (AF), the most common arrhythmia, is due to multiple simultaneous wavelets of reentry in the atria. The only available curative treatment is surgical, using atriotomies to compartmentalize the atria. Therefore, we investigated a staged anatomical approach using radiofrequency catheter ablation lines to prevent paroxysmal AF. METHODS AND RESULTS: Forty-five patients with frequent symptomatic drug-refractory episodes of paroxysmal AF were studied. Progressively complex linear lesions were created by sequential applications of radiofrequency current in the right atrium and then in the left atrium if required. The outcome of the procedure was considered a success when the episodes of AF were either eliminated or recurred at a rate of no more than one episode (lasting < 6 hours) in 3 months. Patients who had no more than one episode per month were considered "improved." Right atrial ablation organized local electrical activity and led to stable sinus rhythm during the procedure in 18 (40%) of the 45 patients. However, sustained AF remained inducible in 40 of 45 patients, and the lesions failed to produce evidence of a significant linear conduction block/delay in all but four patients. There were no significant complications except for two transient sinus node dysfunctions. The procedure duration and fluoroscopic time were 248 +/- 79 and 53 +/- 22 min, respectively. Additional sessions were required in 19 patients to treat sustained right atrial flutter or arrhythmias linked to ectopic right or left atrial foci. During a mean follow-up of 11 +/- 4 months, right atrial ablation was successful in 15 (33%) patients, 6 without medication and 9 with a previously ineffective drug. Nine (20%) additional patients were improved. Ten patients with an unsuccessful outcome then underwent linear ablation in the left atrium. The procedure duration and fluoroscopy time were 292 +/- 94 and 66 +/- 24 min. A hemopericardium occurred in one patient. Two patients required reablation to treat ectopic atrial foci. Left atrial ablation terminated AF during the procedure in 8 patients, and sustained AF could not be induced in 5. Subsequent success was achieved in 6 (60%) patients, including 4 without medication, and 1 additional patient was improved. CONCLUSIONS: Successful radiofrequency catheter ablation of drug-refractory daily paroxysmal AF is feasible using linear atrial lesions complemented by focal ablation targeted at arrhythmogenic foci. Ablation only in the right atrium is a safe technique providing limited success, whereas linear lesions in the left atrium significantly increase the incidence of stable restoration of sinus rhythm, the inability to induce sustained AF, and the final success rate. The described technique is promising but must be considered preliminary because significant improvements are required to optimize lesion characteristics and shorten total procedure duration.
Adult↗
[Catheter ablation and modulation of the atrioventricular junction; current aspects].
Ablation of the atrioventricular junction consists in creating a therapeutic AV block to facilitate the treatment of symptoms caused by atrial arrhythmias refractory to drug therapy. The technical performance of ablation has been improved by restricting the indication to atrial fibrillation, by using radiofrequency currents, by choosing a nodal rather than His bundle ablation site, and by improving the function of cardiac pacemakers (rate adapting, back-up). The functional results are excellent but the outcome is punctuated by rare cases of sudden death, the cause of which is not fully understood (dependance, ventricular arrhythmias, ...). To avoid permanent pacing, it has been suggested that atrioventricular conduction should be modulated rather than completely interrupted. Modulation of the fast pathway has been shown to be ineffective; that of the more complex, slow pathway, seems to be more promising. Although this obviates the need for a pacemaker, it does not suppress irregularity of the ventricular rhythm, the main cause of symptoms in paroxysmal atrial fibrillation and of the haemodynamic changes associated with permanent atrial fibrillation.
Actuarial Analysis↗
[Endocavitary ablation of nodal reentrant tachycardia].
Atrioventricular nodal reentrant tachycardias which, for a long time, could only be treated medically, may now benefit from catheter ablation. The rapid retrograde pathway was an effective initial target but carried a risk of complete atrioventricular block of about 10%. Nowadays, most operators deliver the radiofrequency energy (endocavitary cautery) to the slow nodal pathway. Different techniques of guidance (anatomical, electrophysiological, rapid potential, slow potential) are associated with high success rates: 90 to 100%. However, experimental studies suggest that the slow potentials arise from transitional cells within the tachycardia circuit (the anatomical substrate of the slow pathway). There is still a risk of complete atrioventricular block (1 to 5%) which should be clearly explained to patients referred for ablation of this constantly benign arrhythmia.
Bundle of His↗
Characteristics of the ventricular insertion sites of accessory pathways with anterograde decremental conduction properties.
BACKGROUND: Accessory pathways (APs) with anterograde decremental conduction properties referred to as Mahaim fibers have recently been recognized as originating from the right lateral atrium. Little information is available about their distal insertion. The purpose of this study was to determine the different kinds of APs involved and the characteristics of their distal insertion site. METHODS AND RESULTS: Twenty-one patients (mean age, 28 +/- 13 years) with reciprocating tachycardia or atrial fibrillation were studied. Right-sided atrial and/or ventricular endocardial mapping during tachycardia identified different types of APs. (1) Seventeen patients had long APs originating from the right lateral atrium and coursing several centimeters to the right ventricle. In 10 patients, the AP terminated in or close to the right bundle-branch system (atriofascicular AP) and in 7, the AP terminated in the anterior right ventricle (atrioventricular AP). Patients with atriofascicular APs had narrower QRS complexes (133 +/- 10 versus 165 +/- 26 milliseconds, P = .02) and narrower initial r wave in leads V2 through V4 during maximal preexcitation than patients with atrioventricular APs. In addition, they had earlier His-bundle and right bundle-branch retrograde activation, ie, shorter V-His (16 +/- 5 versus 37 +/- 9 milliseconds, P < .01) and V-right bundle intervals (3 +/- 5 versus 25 +/- 6 milliseconds, P < .01). In 6 patients, minimal preexcitation not readily apparent was present in sinus rhythm despite the appearance of a narrow QRS complex. A wide distal insertion site of 0.5 to 2 cm in diameter consistent with arborization of the AP was found in 10 patients. The distal application of radiofrequency current produced a change in the preexcitation pattern in 4 patients and ablated the AP in 2 patients. In the other patients, radiofrequency current was applied more proximally and successfully ablated the AP bundle (n = 9) or AP proximal insertion (n = 6). No recurrence was observed during a follow-up period of 12 +/- 10 months. (2) Four patients had short paratricuspid atrioventricular APs; in one, the decremental conduction property was acquired as demonstrated by two electrophysiological studies performed 7 years apart. Radiofrequency ablation was successfully accomplished in all 4 patients at the tricuspid annulus. CONCLUSIONS: Different types of APs account for tachycardias previously called Mahaim fibers. Long and short atrioventricular APs are observed in 81% and 19%, respectively. Long APs often have a distal arborization and may have either a fascicular or ventricular insertion. Radiofrequency current is more efficient when applied to the AP bundle or AP proximal insertion rather than to the distal insertion in patients with long APs.
Adult↗
Successful catheter ablation of atrial fibrillation.
INTRODUCTION: Catheter ablation of a case of incessant atrial fibrillation was attempted using linear right atrial lesions created by sequential applications of radiofrequency energy. METHODS AND RESULTS: A 46-year-old patient had incessant episodes of atrial fibrillation. He had previously undergone successful radiofrequency catheter ablation of a common atrial flutter. Antiarrhythmic drugs including amiodarone and various drug combinations were ineffective. A 7-French specially designed 14-polar catheter with interelectrode distance of 3 mm was used to create linear lesions in the right atrium. Each electrode was 4 mm in length and able to transmit radiofrequency energy. Three linear lesions, two longitudinal and one transverse that connected the two longitudinal lesions, were created using 30 radiofrequency applications of 10 to 40 W. The final application interrupted an atrial fibrillation that had been persistent for 55 minutes. No sustained atrial fibrillation was inducible despite repeated pacing maneuvers. There was no complication. In short-term follow-up of 3 months, the patient has been free of arrhythmias without antiarrhythmic medication. CONCLUSION: Successful catheter ablation of human atrial fibrillation is feasible using linear atrial lesions created by radiofrequency energy delivery. Further studies are mandatory to ascertain the efficacy and safety of this procedure, as well as to assess different catheter techniques.
Atrial Fibrillation↗
Electrocardiographic characteristics and catheter ablation of parahissian accessory pathways.
BACKGROUND: Accessory pathways may be located in close proximity to the His bundle, resulting in a high risk of heart block during attempted surgical or electrical interruption of these pathways. This study reports the prevalence, ECG characteristics, and results of catheter ablation of parahissian accessory pathways. They were defined on the basis of both the presence of a high amplitude (> 0.1 mV) of His bundle potential at the ablation site and an exclusion of anteroseptal or midseptal location of the accessory pathway. METHODS AND RESULTS: Eight patients with a parahissian accessory pathway were identified among 582 consecutive patients who underwent radiofrequency ablation of an accessory pathway. They were six males and two females with a mean age of 21 +/- 9 years. During maximal preexcitation, the ECG showed a positive delta wave in leads I, II, and a VF in all patients: six had a negative delta wave in leads V1 and V2 instead of the positivity usually observed in anteroseptal accessory pathways. This pattern had a sensitivity of 75%, a specificity of 96%, a positive predictive value of 86%, and a negative predictive value of 93% for a parahissian location in comparison with a group of 28 patients with anteroseptal accessory pathways. At the successful ablation site, the mean amplitude of the His bundle potential was 0.2 +/- 0.1 (0.12 to 0.4 mV). All accessory pathways were successfully ablated without causing heart block using 5 to 20 W of radiofrequency energy. CONCLUSIONS: Parahissian accessory pathways have a preexcitation pattern that is distinctive from that of anteroseptal accessory pathways. Catheter ablation of these pathways is feasible using low energy with preservation of normal atrioventricular conduction.
Adolescent↗
[Ventricular fibrillation in Wolff-Parkinson-White syndrome. Predictive factors].
The incidence of sudden death in the Wolff-Parkinson-White (WPW) syndrome is not well documented and probably underestimated. This retrospective study concerned 28 consecutive patients presenting with ventricular fibrillation either spontaneously (20) or during electrophysiological investigation (8) but whose characteristics allowed them to be assimilated into a single group. Their clinical and electrophysiological characteristics were compared with those of 60 consecutive patients with the WPW syndrome who had documented atrial fibrillation (and even reciprocating tachycardia) but never ventricular fibrillation. There were no significant differences between the two groups with respect to the following clinical parameters: sex, duration of symptoms, the type of tachycardia previously recorded, history of syncope and presence of underlying cardiac disease. With respect to the electrophysiological data, there were no differences in the point of anterograde block, the effective anterograde refractory period of the accessory pathway, the effective and functional refractory periods of the right atrium and atrial vulnerability. On the other hand, a significant difference was observed in the age of patients with ventricular fibrillation (29 +/- 13 years vs 36 +/- 12 years; p < 0.02), the prevalence of multiple accessory pathways (25% vs 7%; p < 0.04) with a dominant localisation in the postero-septal region (75% vs 47%, p < 0.026), preexcitation during exercise stress testing and under antiarrhythmic therapy (95% vs 68%, p < 0.037). The most discriminating parameter was the shorter RR interval during atrial fibrillation (172 +/- 23 ms vs 230 +/- 50 ms, p < 0.008). Multivariate analysis only showed one independent predictive factor: the minimum preexcited RR interval.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗