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PubMed1998

Risk of thromboembolic events in patients with atrial flutter.

Based on multiple studies, clear, guided anticoagulation therapy is recommended for patients with atrial fibrillation. The value of anticoagulation therapy in patients with atrial flutter, however, is less well established. Little is known about the incidence of thromboembolism in patients with atrial flutter. We evaluated the risk of thromboembolism in 191 consecutive unselected patients referred for treatment of atrial flutter. A history of embolic events was noted in 11 patients. Acute embolism (<48 hours) occurred in 4 patients (3 after direct current cardioversion, 1 after catheter ablation). During follow-up of 26+/-18 months, 9 patients experienced thromboembolic events. During the follow-up, the overall embolic event rate (including acute embolism and thromboembolic events during follow-up) was 7 % in this patient population. Risk indicators for an embolic event in an univariate analysis were organic heart disease (p = 0.037), depressed left ventricular function (p = 0.02), history of systemic hypertension (p = 0.004), and diabetes mellitus (p = 0.0038). Using multivariate analysis, a history of hypertension was the only independent predictor for elevated embolic risk in this patient population (odds ratio = 6.5; 95% confidence intervals 1.5 to 45). Thus, the thromboembolic risk is higher than previously recognized for patients with atrial flutter. Anticoagulation therapy may decrease this risk.

Aged↗
PubMedDate not supplied

Atrial flutter ablation with a new radiofrequency catheter.

OBJECTIVE: To assess the performance of a new radiofrequency catheter, specially designed for inferior vena cava-tricuspid annulus (IVC-TA) isthmus ablation, in the treatment of atrial flutter. PATIENTS: IVC-TA isthmus ablation was performed in thirteen patients, eleven men and two women, aged 60 +/- 12, with a diagnosis of typical atrial flutter, symptomatic despite anti-arrhythmic therapy. The flutter was present for more than one year in seven patients and was paroxysmal in the remainder. The echocardiogram showed atrial enlargement in six patients. Atrial flutter was an isolated phenomenon in seven patients and in the remainder was associated with arterial hypertension (two patients), ischemic heart disease (two patients) and dilated cardiomyopathy (two patients). METHODS: In the electrophysiologic study four diagnostic catheters were used, including one duodecapolar for mapping the tricuspid annulus. In the patients who presented with sinus rhythm, atrial flutter was induced with programmed atrial stimulation, and then the atrial activation circuit was mapped. To demonstrate the entrainment phenomenon the IVC-TA isthmus was over-stimulated, to prove that this was the slow zone of the circuit. The radiofrequency energy was applied in the IVC-TA isthmus with the Medtronic Cosio-Fluttr ablation catheter, for 60 sec per application, with temperature control and with a maximum energy output of 50 W. Criteria for success were not only the disappearance of the atrial flutter during the application of radiofrequency energy, but also the demonstration of bi-directional IVC-TA isthmus block. RESULTS: The primary success rate was 100%. The mean procedure time was 110 +/- 22 min, mean fluoroscopy time was 23 +/- 4 min and the number of radiofrequency energy pulses was 9 +/- 3. There were no complications. The patients were followed for a mean time of 8 +/- 4 months and atrial flutter recurred in only one patient (8%). CONCLUSIONS: Atrial flutter ablation with the new Medtronic Cosio-Fluttr catheter, specially designed for the application of radiofrequency at the IVC-TA isthmus, is a safe procedure and has a high success rate. It simplifies ablation, decreasing the number of radiofrequency energy pulses, without using long sheaths and keeping short procedure and fluoroscopy times.

Adult↗
PubMed1984

Intra-atrial reentry as a mechanism for atrial flutter induced by acetylcholine and rapid pacing in the dog.

In the isolated blood-perfused canine heart we produced episodes of rapid atrial flutter by continuous infusion of acetylcholine and rapid pacing. The spread of excitation during atrial flutter was mapped with the aid of two endocavitary mapping electrodes containing 960 leads and recording from 192 different sites simultaneously. The flutter maps clearly showed that intra-atrial reentry was the mechanism responsible for the arrhythmia. However, the localization and size of the intra-atrial circuits differed from case to case even in the same heart. The orifices of the venae cavae or the atrioventricular ring did not serve as a central anatomic obstacle for circus movement. We also failed to identify a special role of the internodal pathways in the formation of the loop. Instead, the intra-atrial circuits could be found everywhere, provided sufficient atrial mass was available to accommodate the circuit. The diameter of the circuits varied between 1.5 and 3 cm at a cycle length between 65 and 155 msec. The average conduction velocity of the circulating impulse varied between 60 and 80 cm/sec. Spontaneous termination of atrial flutter frequently occurred and was based on local conduction block in a narrow part of the circuit. Another interesting aspect of these studies is the finding that during continuous circus movement of the impulse, the amount of myocardium that is activated may vary considerably. This marked periodicity in excited tissue mass during atrial flutter could adequately explain the continuously undulating baseline or typical sawtoothlike F waves as seen in the surface electrocardiogram during atrial flutter.

Acetylcholine↗
PubMed1991

[An experimental study on supraventricular dysrhythmias after intracardiac surgery, with special reference to relationship between injury of the internodal tract and atrial flutter].

Dysrhythmias after atrial reparative surgery for TGA or ASD can be lethal. Experiments were made to analyze their mechanism, and to search preventive methods. 1. Acute effects of atrial incisions were studied by epicardial mapping on the right atriums (RA) subjected to various incisions with or without internodal tract (INT) involvement 101 dogs. Atrial rapid pacing was used to induce sustained AF or af. 2. Chronic effects of atrial incisions were studied on longitudinal incisions with (8 dogs) or without (8 dogs) posterior INT (PINT) involvement. Few months later they were subjected to mapping, inducibility of AF, and histologic study of hearts. 3. Mechanism of induced AF was analyzed using reentrant circuit of AF in the longitudinal PINT incision group. At acute stage, conduction delay specific to each freewall incision was observed. AF or af was induced in 70.0% of the longitudinal incision with PINT involvement, but only in 1 dog without PINT. At chronic stage, AF was induced in 5 dogs (62.5%) which included 4 dogs not showed AF at acute stage. Marked chronic changes were histologically showed in injured atrial portion. Reentrant circuit of AF was demonstrated on RA near tricuspid orfice. The PINT kept intact is important to prevent AF.

Adult↗
PubMed2005

Role of electrophysiological study and ablation in the management of recurrent atrial flutter associated with haemodynamic compromise in a critically ill patient.

Atrial flutter is a common arrhythmia. In the critical care setting, the arrhythmia may present in any patient, but it is most commonly seen in patients with impaired ventricular function, valvular disease, atrial dilatation or after cardiac surgery. We present a 68-year-old lady with recurrent poorly tolerated atrial flutter that was resistant to multiple pharmacological interventions and complicated by cardiogenic shock following direct current cardioversion. The flutter was successfully cured with radiofrequency ablation and was followed by an immediate improvement in her haemodynamic status. We review the management of acute atrial flutter and discuss the role of electrophysiologically guided ablation.

Aged↗
PubMed1988

Facilitating influence of disopyramide on atrial flutter termination by overdrive pacing.

Long-lasting (mean 30 days) type I atrial flutter was treated with overdrive pacing in 30 patients (mean age 69 years) with organic heart disease. To evaluate the effect of pretreatment with disopyramide, the study population was divided in 3 groups of 10 patients each: group A, no disopyramide therapy; group B, intravenous disopyramide (maximum dose 250 mg in 1 hour); and group C, oral disopyramide (400 mg daily for 4 days). There were no differences in baseline cycle length of atrial flutter among the 3 groups before drugs were given. The stimulation protocol included overdrive atrial pacing up to the shortest paced cycle of 150 ms performed at a maximum of 3 atrial sites. Reversion to sinus rhythm occurred in 2 patients in group A, 7 in group B (p less than 0.01) and 5 in group C. Pacing was performed from a mean number of 2.1 sites/patient in group A, 1.2 in group B and 2.0 in group C. Atrial fibrillation occurred in 7, 3 and 4 patients, respectively. Acceleration to a faster form of atrial flutter occurred in 3, 3 and 4 patients, respectively, and reversion to sinus rhythm occurred in all patients who had intravenous disopyramide and in 1 who took the drug orally. The administration of disopyramide before overdrive pacing improved the rate of conversion to sinus rhythm and allowed an easier stimulation protocol with a lower incidence of pacing-induced atrial fibrillation. Disopyramide is beneficial when overdrive atrial pacing is performed for the treatment of long-standing atrial flutter in patients with organic heart disease.

Administration, Oral↗
PubMed2000

Nonlinear ablation targeting an isthmus of critically slow conduction detected by high-density electroanatomical mapping for atypical atrial flutter.

Focused high-density atrial endocardial mapping was performed with a three-dimensional electroanatomical mapping system or a multielectrode basket catheter in six men and two women (mean age = 54 years) with atypical atrial flutter (AFL) to characterize its reentry circuit and identify its isthmus of critically slow conduction (ICSC). Activation mapping revealed figure-8 reentry with ICSC between a surgical atrial scars in three atypical AFLs following atriotomy, and between the crista terminalis (CT) and the inferior (IVC) or superior (SVC) vena cavae in atypical right atrial (RA) AFL in absence of prior atriotomy. Figure-8 double loop reentry was documented in one RA atypical AFL. ICSC was characterized by concealed entrainment with a post-pacing interval identical to the AFL cycle length, and a mid-diastolic fractionated electrogram, 129 +/- 23 ms in duration, spanning the isoelectric line between double potentials on adjacent area of conduction block. All AFLs were successfully ablated with 4.9 +/- 4.3 RF pulses applied at ICSC. A possible mechanism of atypical AFL consists of figure-8 reentry with ICSC between surgical scars in postoperative AFL, and between the CT and the IVC/SVC in RA AFL not preceded by cardiac surgery. Late and partial regeneration of conduction across the atriotomy scar can create an ICSC. Nonlinear ablation targeting ICSC can cure atypical AFL, whether it follows surgery or not.

Atrial Flutter↗
PubMed2003

Relationship between left atrial appendage function and left atrial thrombus in patients with nonvalvular chronic atrial fibrillation and atrial flutter.

The relationship between the left atrial appendage (LAA) function, as assessed by transesophageal echocardiography, and the incidence of left atrial thrombus was evaluated in 62 patients with nonvalvular chronic atrial fibrillation (AF; n=50) and atrial flutter (AFL; n=12). It was hypothesized that in both AF and AFL not only the LAA flow velocity (LAAFV), but also the frequency of the LAA movement (the LAA flow time, LAAFT) is a major contributing factor to thrombus formation. LAAFT was defined as the average duration of LAA flow with emptying and filling waves. The patients with AF were divided into 2 groups: lone AF (n=14) and non-lone AF (n=36). LAA thrombus was found in 6 patients with none-lone AF. LAAFV was lower and LAAFT was shorter in patients with thrombus as compared with patients without thrombus (12.0+/-2.2 cm/s vs 24.1+/-10.6 cm/s, 68.7+/-1.5 ms vs 72.9+/-3.3 ms, p<0.01, respectively). Patients with AFL had higher LAAFV and longer LAAFT than those with chronic AF. The present data suggest that, in addition to LAAFV, LAAFT characterized LAA function and might serve as a predictor of thrombus formation in chronic AF. With respect to LAA function, patients with lone AF or AFL are at low risk for thrombus formation.

Aged↗
PubMed2001

Prospective evaluation of catheter ablation in patients with implantable cardioverter defibrillators and multiple inappropriate ICD therapies due to atrial fibrillation and type I atrial flutter.

The high incidence of inappropriate therapies due to drug refractory supraventricular tachycardia remains a major unsolved problem of the ICD. Most of the inappropriate therapies for supraventricular tachycardia are caused by AF and type I atrial flutter with rapid ventricular response. The purpose of this prospective study was to determine the usefulness of AVN modulation or ablation for rapid AF and ablation of the tricuspid annulus-inferior vena cava (TA-IVC) isthmus for type I atrial flutter in ICD patients with frequent inappropriate ICD interventions. Eighteen consecutive patients were enrolled in this study. Twelve patients received a mean of 34 +/- 36 antitachycardia pacing (ATP) and 41 +/- 32 shock therapies for rapid AF during 49 +/- 39 months, and 6 patients a mean of 111 +/- 200 ATP and 11 +/- 8 shock therapies for type I atrial flutter during 52 +/- 37 months preceding ablation procedure. Modification of the AVN was successful in 10 (83%) of 12 AF patients, in 2 (17%) patients ablation of the AVN was performed. A complete TA-IVC isthmus block was achieved in 5 (83%) of 6 atrial flutter patients. Three (25%) AF patients had 11 +/- 24 recurrences of ATP and 0.4 +/- 1.1 shock therapies for rapid AF during 15 +/- 7 months. None of the atrial flutter patients had recurrences of inappropriate therapies for type I atrial flutter during 14 +/- 8 months, but two (33%) patients had inappropriate ICD therapies for type II atrial flutter or rapid AF. There was an overall mean incidence of 18 +/- 22 inappropriate ICD therapies per 6 months before and 4 +/- 9 per 6 months after the ablation procedure (P < 0.05). In conclusion, radiofrequency catheter modification or ablation of the AVN for rapid AF and ablation for atrial flutter type I are demonstrated to be highly effective in the majority of ICD patients with drug refractory multiple inappropriate ICD therapies.

Aged↗
PubMed2006

[Atrial flutter ablation: initial experience in a general hospital].

BACKGROUND: Right atrial flutter has a relatively high incidence. It is often symptomatic and can have a poor outcome particularly in case of thrombo-embolic events. AIM OF STUDY: We evaluate the results of radiofrequency catheter ablation for right atrial flutter since the introduction of this technique inour hospital. METHODS: The 28 first patients referred in our institution for atrial flutter and relevant for cavo-tricuspid isthmus ablation were enrolled. Ablation used a 8 mm tip electrode catheter and one or two conventional diagnostic catheters. The goal of ablation was complete bidirectional isthmus block. RESULTS: The first-line success rate was 96 percent with 4 percent early flutter recurrence. The mean duration of radiofrequency current applications was 652 +/- 409 seconds. No complication was observed. CONCLUSION: This results are comparable with the published data and encourage the development of basic ablation procedures and maintenance of rhythmic competence in general hospital inside medical network.

Aged↗
PubMed1996

Activation and entrainment mapping defines the tricuspid annulus as the anterior barrier in typical atrial flutter.

BACKGROUND: The importance of anatomic barriers in the atrial flutter reentry circuit has been well demonstrated in canine models. It has been shown previously that the crista terminalis and its continuation as the eustachian ridge form a posterior barrier. In this study we tested the hypothesis that the tricuspid annulus forms the continuous anterior barrier to the flutter circuit. METHODS AND RESULTS: Thirteen patients with typical atrial flutter were studied. A 20-pole halo catheter was situated around the tricuspid annulus. A mapping catheter was used for activation and entrainment mapping from seven sequential sites around the tricuspid annulus and from three additional sites including the tip of the right atrial appendage, at the fossa ovalis, and in the distal coronary sinus. Sites were considered to be within the circuit when the postpacing interval minus the flutter cycle length and the stimulus time minus the activation time were < or = 10 ms; sites were considered to be outside the circuit when these intervals were > 10 ms. All seven annular sites were within the circuit; activation occurred sequentially around the annulus and accounted for 100% of the flutter cycle length. The fossa ovalis, the distal coronary sinus, and the right atrial appendage were outside the circuit. CONCLUSIONS: Closely spaced sites around the tricuspid annulus are activated sequentially, and are all within the flutter circuit according to entrainment criteria. This demonstrates that the tricuspid annulus constitutes a continuous anterior barrier constraining the reentrant wave front of human counterclockwise atrial flutter.

Aged↗
PubMed2006

A randomized clinical trial of continuous flow nitrous oxide and nalbuphine infusion for sedation of patients during radiofrequency atrial flutter ablation.

BACKGROUND: In patients with common atrial flutter (CAF), radiofrequency ablation (RFA) causes discomfort. Patients undergoing RFA often feel pain which is difficult to control as the mechanisms are unclear. HYPOTHESIS: Inhaled nitrous oxide (N2O) is a potent sedative-analgesic-anxiolytic agent that may relieve anxiety and discomfort during CAF ablation. METHODS AND RESULTS: In a prospective randomized study, the effect of Inhaled N2O was compared with that of intravenous sedation with Nalbuphine during CAF ablation in 76 patients (64 +/- 13 years, 56 men). We used a 24 pole mapping catheter around the tricuspid annulus and a 8-mm tip ablation catheter for each patient. Forty-two patients (group 1) underwent radiofrequency (RF) application to the cavotricuspid isthmus 5 minutes after the beginning of inhalation of a (50% N2O/50% O2) mixture. Thirty-four patients (group 2), underwent the first RF application 15 minutes after the end of an infusion of Nalbuphine (20 mg delivered over 15 minutes). Ablation-related anxiety and discomfort were assessed using a visual analog scale (VAS) ranging from 0 to 100 mm, with 0 correlating to the statement "no pain at all" and 100 with "the worst possible pain." The VAS score was determined at the end of each application. The number of RF applications (group 1; 10 +/- 8 vs group 2; 11 +/- 6, P = NS) and procedure duration (group 1; 75 +/- 53 minutes vs group 2; 72 +/- 45 minutes, P = NS), were similar for the two groups. N(2)O sedation compared with nalbuphine infusion reduced VAS for anxiety (10 mm +/- 8 vs 58 mm +/- 22, P < 0.05) and for discomfort (18 mm +/- 9 vs 45 mm +/- 34, P < 0.01), respectively. Although there was more frequent vomiting in group 1; 7 of 42 (17%) than in group 2; 3 of 34 (9%), P < 0.05, patients were less likely to have hypotension during the procedure 1 of 42 (2.5%) versus 4 of 34 (12%), P < 0.05, respectively. CONCLUSION: Inhalation of a (50% N2O/50% O2) mixture during RF ablation for atrial flutter is a safe and efficient way to reduce anxiety and discomfort caused by RF applications.

Administration, Inhalation↗
PubMed2006

Current treatment options for atrial flutter and results with cryocatheter ablation.

Rhythm disturbances arising in the upper chambers of the heart are not uncommon. They are associated with a heavy burden of illness for the affected individual, as well as society in general. Atrial flutter, a re-entrant atrial tachycardia, is one such rhythm disturbance. The objective of this review article is twofold: first, to provide a brief insight into atrial flutter and the typical treatments for this arrhythmia in clinical practice; and second, to give an in-depth account of cryocatheter ablation as a relatively new treatment option for this potentially debilitating condition. The many recent clinical studies documenting the use of cryocatheter ablation for treatment of atrial flutter are presented, and their results briefly discussed. Overall, as cryocatheter ablation embeds itself among the arsenal of treatments for atrial flutter, the promising results from clinical studies appear destined to elevate cryocatheter ablation to a premier position among the treatment options for atrial flutter.

Anti-Arrhythmia Agents↗
PubMed1991

Simulated myocardial infarction and slow atrial flutter due to cerebral embolism from a free left atrial thrombus.

The case of a 38-year-old female who suffered a cerebral embolism from a free left atrial thrombus is reported. The clinical picture, including serum enzyme elevations, was consistent with a nontransmural myocardial infarction. Atrial flutter exhibiting very slow (162/min) and tall waves was transiently recorded indicating development of an intra-atrial conduction disturbance.

Adult↗
PubMed2005

[Results of radiofrequency ablation of the inferior vena cava-tricuspid valve isthmus for atrial flutter].

BACKGROUND: Radiofrequency ablation of the inferior vena cava-tricuspid valve isthmus relieves atrial flutter in 95% of cases. AIM: To evaluate the long term results of radiofrequency ablation of the inferior vena cava-tricuspid valve isthmus in atrial flutter. MATERIAL AND METHODS: Retrospective review of 86 patients with common atrial flutter, treated with radiofrequency ablation of the isthmus, while in sinus rhythm or flutter. Patients were contacted by telephone for a new clinical and electrocardiographic assessment, three to 40 months after the procedure. RESULTS: Of all the patients treated, five died and five were lost from follow up, thus 76 patients (mean age 56 years, 58 males) were contacted for reassessment. At the moment of the procedure, 51% had an underlying cardiac disease and 25% had high blood pressure. All referred palpitations, 25% had dyspnea, 84% were receiving antiarrhythmic drugs and 33% were on oral anticoagulants. Flutter was paroxystic in 83% and chronic in 17%. Fulguration was successful in all patients; one patient presented a high grade atrioventricular block as a complication of the procedure. At reassessment, 82% of patients were in sinus rhythm, 16% had atrial fibrillation and 2%, an atypical flutter. CONCLUSIONS: Radiofrequency fulguration is a safe and effective treatment of atrial flutter.

Adult↗
PubMed1991

Effects of antiarrhythmic drugs on canine atrial flutter due to reentry: role of prolongation of refractory period and depression of conduction to excitable gap.

Antiarrhythmic drugs prolong the effective refractory period and depress conduction. To determine the exact role played by these two electrophysiologic effects in the termination of reentry, the effects of disopyramide, flecainide, propafenone and E-4031, a new class III drug, were examined in a canine model of atrial flutter (cycle length 120 +/- 4 to 131 +/- 3 ms) caused by reentry. Atrial flutter was induced in 32 anesthetized open chest dogs after placement of an intercaval crush. The excitable gap ranged from 9 +/- 2% to 11 +/- 4% of the basic flutter cycle length. The effective refractory period in the reentrant circuit during atrial flutter was estimated by subtracting the excitable gap from the basic flutter cycle length. Prolongation of flutter cycle length by the test drugs was proportional to the interatrial conduction time (r = 0.87, p less than 0.001). Atrial flutter was terminated by each test drug in all dogs except for flecainide and propafenone in one dog each. E-4031 prolonged the refractory period during atrial flutter to 129 +/- 6 ms, which did not differ significantly from the flutter cycle length immediately before termination (134 +/- 4 ms). The refractory period during atrial flutter after injection of the other drugs was shorter than the flutter cycle length before termination of atrial flutter (for example, flecainide 126 +/- 5 vs. 179 +/- 11 ms, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Various routes of septal propagation in common atrial flutter.

INTRODUCTION: Although in the treatment of common atrial flutter, the isthmus between the tricuspid valve annulus and the eustachian ridge is often chosen as the site for conduction block by radiofrequency ablation, the precise path of the flutter circuit remains unknown. We therefore investigated the propagation of the atrial flutter wave front around the coronary sinus ostium and how its path is altered by application of radiofrequency current. METHODS AND RESULTS: To assess activation pattern, activation in the region surrounding the coronary sinus ostium was mapped using a deflectable decapolar catheter under basal conditions and while applying radiofrequency current to the septal isthmus, between the tricuspid valve annulus and the eustachian ridge. In five of eleven patients studied, the eustachian ridge side, below the coronary sinus ostium, was activated earlier, and the flutter wave exited from either the tricuspid valve annulus side or the eustachian ridge side, above the coronary sinus ostium. In four patients, a partial line of block created by applying radiofrequency current between the tricuspid valve annulus and the coronary sinus ostium or between the coronary sinus ostium and the eustachian ridge led to a shift in the direction of propagation of the flutter wave front from anterior to posterior or from posterior to anterior of the coronary sinus ostium, and prolongation of the cycle length. CONCLUSION: Application of radiofrequency current to the septal isthmus, between the tricuspid valve annulus and the eustachian ridge, can shift both the anterior and posterior propagation of flutter around the coronary sinus ostium.

Aged↗
PubMed1982

Inter- and intraatrial dissociation during spontaneous atrial flutter: evidence for a focal origin of the arrhythmia.

Programmed electrical stimulation of the heart was performed in 2 patients with spontaneous atrial flutter. Patient 1 was a young man with paroxysmal atrial flutter that had proved resistant to drug therapy and who was studied during an episode of sustained flutter. In this patient rapid atrial pacing from the coronary sinus at a critical rate faster than the intrinsic flutter rate provoked local atrial fibrillation in the mid and low right atrium which persisted after termination of pacing. In spite of persistent local fibrillation in these regions, atrial flutter continued in the left atrium and the high right atrium. A second burst of pacing resulted in restoration of sinus rhythm. Patient 2 was an elderly woman with probable sick sinus syndrome who developed spontaneous atrial flutter during the course of an electrophysiologic investigation. During flutter intracavitary recordings from multiple sites in the atria revealed a pattern of 3:2 Wenckebach conduction between the left atrium and the high right atrium, with block of every third atrial depolarization at the latter site. These results indicate that atrial flutter may exist at some sites in the atria which are functionally dissociated from the remainder of the atrial tissue, thus supporting the hypothesis that flutter in some patients may be focal in origin.

Adult↗