Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Atrial Flutter”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
PubMed2005

Radiofrequency ablation of typical atrial flutter with the use of electro-anatomical mapping system CARTO.

BACKGROUND: Radiofrequency (RF) ablation of typical atrial flutter (AFL) is a well-established method of treatment. Although its efficacy is high, a search for new, more effective techniques is continuing. These new methods include modern systems for electro-anatomical mapping and new types of ablating electrodes such as cooled-tip or dual-sensor catheters. AIM: To assess the efficacy of RF ablation of typical AFL with the use of electro-anatomical mapping system CARTO and to compare the effectiveness of various ablating catheters. METHODS: The study group consisted of 60 consecutive patients who underwent RF ablation of typical AFL with the use of the CARTO system. In 35 patients standard ablating electrodes were used, in 15 -- cooled-tip catheters (Thermo-Cool), and in 10 -- Dual-Sensor catheters. RESULTS: Overall efficacy of RF ablation was 96.6%. In two procedures which occurred ineffective, standard ablating electrodes were used. In 4 (6.6%) patients a recurrence of AFL was noted -- also these patients had RF ablation performed with the use of standard ablating electrodes. None of the patients had procedure-related complications. CONCLUSIONS: RF ablation of typical AFL with the use of electro-anatomical system CARTO is effective, safe and associated with reduced fluoroscopy time. The use of cooled-tip or dual sensor ablating electrodes further enhances efficacy of the procedure.

Aged↗
PubMed2001

Double potentials along the ablation line as a guide to radiofrequency ablation of typical atrial flutter.

OBJECTIVES: The purpose of this study was to determine the characteristics of double potentials (DPs) that are helpful in guiding ablation within the cavo-tricuspid isthmus. BACKGROUND: Double potentials have been considered a reliable criterion of cavo-tricuspid isthmus block in patients undergoing radiofrequency ablation of typical atrial flutter (AFL). However, the minimal degree of separation of the two components of DPs needed to indicate complete block has not been well defined. METHODS: Radiofrequency ablation was performed in 30 patients with isthmus-dependent AFL. Bipolar electrograms were recorded along the ablation line during proximal coronary sinus pacing at sites at which radiofrequency ablation resulted in incomplete or complete isthmus block. RESULTS: Double potentials were observed at 42% of recording sites when there was incomplete isthmus block, compared with 100% of recording sites when the block was complete. The mean intervals separating the two components of DPs were 65 +/- 21 ms and 135 +/- 30 ms during incomplete and complete block, respectively (p < 0.001). An interval separating the two components of DPs (DP(1-2) interval) <90 ms was always associated with a local gap, whereas a DP(1-2) interval > or =110 ms was always associated with local block. When the DP(1-2) interval was between 90 and 110 ms, an isoelectric segment within the DP and a negative polarity in the second component of the DP were helpful in indicating local isthmus block. A DP(1-2) interval > or =90 ms with a maximal variation of 15 ms along the entire ablation line was an indicator of complete block in the cavo-tricuspid isthmus. CONCLUSIONS: Detailed analysis of DPs is helpful in identifying gaps in the ablation line and in distinguishing complete from incomplete isthmus block in patients undergoing radiofrequency ablation of typical AFL.

Action Potentials↗
PubMed1998

Resolution of cardiomyopathy after ablation of atrial flutter.

OBJECTIVES: We sought to serially assess left ventricular (LV) function before and after catheter ablation of atrial flutter (AFI). BACKGROUND: The relation of tachycardia-induced cardiomyopathy to AFI and its response to direct catheter ablation are unknown. METHODS: LV function was assessed in a series of 59 consecutive patients with successful radiofrequency ablation (RFA) of AFI before and after the procedure. Eleven patients had dilated cardiomyopathy (LV ejection fraction [LVEF] <50%) and congestive heart failure (CHF) symptoms and are the subject of this report. LV function was assessed by LVEF on two-dimensional echocardiography and functional status by New York Heart Association (NYHA) CHF classification. RESULTS: Patients were 59 +/- 8 years old, and were all male. Five patients had a preablation diagnosis of idiopathic cardiomyopathy. The preablation LVEF was 30.9 +/- 11.0% and improved to 41.3 +/- 16% (p = 0.005) when measured 7 months after successful ablation. NYHA CHF class improved from 2.6 +/- 0.5 to 1.6 +/- 0.9 (p = 0.002). Six (55%) of 11 patients had normalization of the LVEF, with complete resolution of CHF symptoms. A lower preablation LVEF and functional class predicted nonresolution of dilated cardiomyopathy (p = 0.002 and 0.001, respectively). CONCLUSIONS: Restoration of normal sinus rhythm by RFA in patients with chronic AFI and cardiomyopathy substantially improved LV function. Resolution of dilated cardiomyopathy occurred in the majority of patients. Tachycardia-induced cardiomyopathy may be a more common mechanism of LV dysfunction in patients with AFI than expected, and aggressive treatment of this arrhythmia should be considered.

Adult↗
PubMed2003

Safety and efficacy of radiofrequency ablation of common atrial flutter in elderly patients: a single center prospective study.

Little data is available concerning the invasive treatment of atrial flutter (AFL) in elderly patients. The purpose of this prospective study was to evaluate the risks, safety, and follow-up of radiofrequency (RF) catheter ablation of common AFL in patients >75 years old (n = 61) (Group I) compared to patients younger than 75 years (n = 187) (Group II). The study population consisted of 248 patients (81% men/19% women), 21 to 96 years old (mean 66.3 +/- 12 years) with AFL, referred for RF from June 1999 to June 2001. RF endpoint was the assessment of the bidirectional block. The cumulative risk of atrial fibrillation (AF) was analyzed by the Kaplan-Meier method and log-rank test. The mean follow-up was 12.4 +/- 9 months. No complication occurred. Group I (80.1 +/- 4.5 years) did not differ significantly from Group II (61 +/- 11 years) regarding: AF history before ablation (34.4% vs 39.8%), structural heart disease (54% vs 42%), LVEF (57%+/- 12% vs 58%+/- 12%), left atrial size (43.8 +/- 7 vs 42.5 +/- 7), cava-tricuspid isthmus dimension (40 +/- 10 vs 39 +/- 4 mm), bidirectional block (100% vs 96.2%), RF application (12.5 +/- 10 vs 13.5 +/- 12 minutes), AFL recurrence (3.3% vs 5.3%), antiarrhythmic agents at hospital discharge (34.4% vs 38.9%), mean follow-up (12 +/- 9 vs 13 +/- 9 months) and AF occurrence (29.5% vs 20.3%; P = 0.2). Of these, the incidence of AF in patients without prior history (n = 150) was 7 (18%) of 39 for Group I and 11 (10%) of 111 for Group II (P = 0.1) after follow-up. Catheter ablation of AFL in very elderly patients appears to be a reasonable approach regarding feasibility, effectiveness, and low procedural risk.

Adult↗
PubMed1994

Laser catheter ablation of atrial flutter and of atrioventricular nodal reentrant tachycardia in a single session.

This report describes an adolescent with refractory atrial flutter (AF) and atrioventricular (AV) nodal reentrant tachycardia who was cured by Nd: YAG, 1064 nm, laser application. Two impacts of 30 s each (power 30 W and irradiated spot diameter 2.0-2.5 mm), applied via a novel laser catheter system, abolished both AF and AV nodal reentrant tachycardia. The procedure was without complications or recurrent arrhythmias.

Adolescent↗
PubMed1991

Effects of sympathetic and parasympathetic stimulation on the induction of atrial flutter in dogs with aseptic pericarditis.

To study the effects of sympathetic stimulation (SS) and vagal stimulation (VS) on the induction of atrial flutter (AF) and its cycle length, aseptic pericarditis was produced surgically in 17 adult mongrel dogs. Programmed atrial stimulation was used to induce AF and to determine the effective refractory periods (ERP) and maximum conduction delay (maxCD) of the atrium. These tests were performed before and during stimulation of the right cervical vagus nerve and the right stellate ganglion. Results showed: (1) AF could be induced in animals with short ERP and large maxCD before SS; (2) ERP was significantly shortened, maxCD was significantly increased by VS; (3) During SS, ERP was slightly shortened, but there were no changes in maxCD and the induction rate of AF; (4) The cycle length of AF was shortened by SS, however, the cycle length of AF was shortened more notably by VS than by SS. From these findings, a shortening of the ERP and an increase in maxCD appear to be related to an increased AF induction rate by VS.

Animals↗
PubMed2001

Biatrial activation in isthmus-dependent atrial flutter.

BACKGROUND: The aim of this study was to determine the biatrial activation pattern in isthmus-dependent atrial flutter (AFL) to understand the functional interatrial connections and the activation pattern of the left atrium (LA). METHODS AND RESULTS: Biatrial activation was performed, using an electroanatomic mapping system, in 10 patients undergoing right atrial isthmus ablation for counterclockwise (n=7) or clockwise (n=3) AFL. The AFL circuit was peritricuspid and propagated slowly (0.5+/-0.2 m/s) through the isthmus. LA was activated by two wave fronts, with discrete breakthroughs in the superior, mid, or inferior atrial septum. The activation of LA overlapped 50+/-16% of the AFL cycle length. In counterclockwise AFL, at least one breakthrough was located in the inferior atrial septum. LA activation began immediately after the exit of the flutter wave from the isthmus and was directed inferosuperiorly in all patients, being synchronous with the atrial septal activation. The septal breakthroughs in patients with clockwise AFL were variably located. The direction of LA activation was superoinferior in 2 and inferosuperior in 1 patient. CONCLUSIONS: The circuit of isthmus-dependent AFL was entirely in the right atrium. LA activation was a bystander and followed trans-septal conduction across the inferior coronary sinus-LA connection, Bachmann's bundle, and/or fossa ovalis.

Atrial Flutter↗
PubMed1999

Quantitative analysis of surface P-wave morphology in isthmus ablation for type 1 atrial flutter: differentiation between complete isthmus block and slow isthmus conduction.

Changes in P-wave morphology in inferior leads during atrial pacing at the margins of the carvo-tricuspid isthmus have been reported to be useful for predicting the creation of isthmus block in radiofrequency (RF) ablation of type I atrial flutter (AFL). However, it is not known whether these changes in P-wave morphology allow the clinician to differentiate between complete isthmus block and slow isthmus conduction. P-wave morphology during low lateral right atrial (LLRA) pacing, as well as during coronary sinus ostium (PCS) pacing, was evaluated prior to ablation, during slow isthmus conduction, and after complete isthmus block in 30 patients with AFL. Changes in P-wave morphology during LLRA pacing were not sufficient to differentiate between complete isthmus block and slow isthmus conduction. While changes in P-wave morphology in lead II from inverted to biphasic during PCS pacing were observed in both slow isthmus conduction and complete isthmus block, the ratio of the positive component to the total P-wave amplitude (P-wave ratio) was significantly different between slow isthmus conduction (20+/-17%) and complete isthmus block (40+/-11%) (P<0.0001). When the P-wave ratio in lead II during PCS pacing was more than 75% of the F-wave ratio in lead II during AFL, bilateral complete isthmus block was predicted with a sensitivity of 88%, a specificity of 71%, a positive predictive value of 75%, and a negative predictive value of 85%. These results indicate that a P-wave ratio greater than 20% or a P-wave ratio during PCS pacing greater than 75% of the F-wave ratio during AFL may predict a bidirectional complete isthmus block.

Aged↗
PubMed2003

Identification of functional block line in atrial flutter using three-dimensional intracardiac echocardiography.

The crista terminalis (CT) is reportedly a critical barrier for maintaining typical atrial flutter (AFL), but recent observations have suggested the presence of posteromedial functional block, as well as crista conduction. Therefore, this study was designed to identify the correlation between the posterior boundary of AFL and anatomical architecture in the human right atrium (RA) using 3-dimensional (D) intracardiac echocardiography (ICE). In 11 patients with AFL (typical 9, reverse typical 2), mapping with a 10-pole (n=5) or 32-pole (n=6) catheter was performed during AFL. ICE was used to determine the catheter's position relative to the intra-atrial structures. In all patients, double potentials were recorded at the posteromedial RA and the catheter positions were recognized as posterior to the CT by 3-D ICE. Double potentials were not recorded on the CT, and the activation sequence revealed a craniocaudal direction in the 9 patients with typical AFL and caudocranial direction in the 2 patients with reverse typical AFL. These findings demonstrate that the posterior boundary of the AFL circuit is in the sinus venosa region posterior to the CT, which may provide an important insight into the mechanism of maintaining AFL.

Adult↗
PubMed2001

Role of functional block extension in lesion-related atrial flutter.

BACKGROUND: A line of block in the right atrium (RA) between the venae cavae is necessary to obtain classic atrial flutter (AFL). We tested the hypothesis that the location of that line of block would determine whether the AFL reentrant circuit would be due to single-loop reentry or figure-of-8 reentry. METHODS AND RESULTS: Simultaneous mapping from 392 sites (both atria and the atrial septum) was performed in 13 normal dogs before and after creating a linear lesion on the RA free wall. The lesion was 1 to 1.5 cm anterior and parallel to the crista terminalis (7 dogs) or posterior and close to the crista terminalis region (6 dogs). Sustained AFL (>2 minutes) was then induced. In 4 dogs with an anterior lesion, the AFL reentrant circuit traveled around the lesion (lesion reentry). In 9 dogs (3 with anterior lesions and 6 with posterior lesions), the AFL reentrant circuit included the anterior RA free wall, the atrial septum, and Bachmann's bundle (single-loop reentry). In these 9 dogs, the fixed line of block was extended to the superior and/or inferior vena cava by a functional line of block, thereby preventing lesion reentry. No figure-of-8 reentry was induced. CONCLUSIONS: In this model, the location of a fixed line of block and its functional extension determine the type of AFL reentry. These data provide an explanation for the chronic AFL that occurs in some patients after surgical repair of congenital heart lesions.

Animals↗
PubMed2004

Efficacy of a microwave antenna for ablation of the tricuspid valve--inferior vena cava isthmus in dogs as a treatment for type 1 atrial flutter.

INTRODUCTION: Radiofrequency catheter ablation of the tricuspid valve-inferior vena cava (TV-IVC) isthmus for treatment of atrial flutter (AFL), may in some cases require a large number of energy applications and a long procedure and fluoroscopy time. AIMS OF STUDY: Therefore, we studied the safety and efficacy of a 4 cm long microwave antenna mounted on a steerable 9Fr catheter for linear ablation of the TV-IVC isthmus. METHODS: In 6 anesthetized dogs, multi-electrode catheters were positioned in the coronary sinus (decapolar), at the His bundle (quadripolar) and around the TV annulus (decapolar) for pacing and recording atrial activation sequences before and after ablation. The microwave antenna was then positioned across the TV-IVC isthmus from the TV annulus (identified by equal A and V potentials) to the inferior vena cava with slight traction on the catheter to ensure adequate endocardial contact. Microwave energy was then applied at a fixed power for 120 seconds during each ablation attempt. Ablation was repeated until bi-directional isthmus block was demonstrated during pacing from the coronary sinus ostium and low lateral right atrium, respectively. RESULTS: Linear microwave ablation of the TV-IVC isthmus was completed in all ten dogs using a total of 2.6 +/- 1.17 energy applications per dog. Power was applied in a range of 45-50 watts. There were no acute procedural complications. Bi-directional TV-IVC isthmus block was achieved in all ten dogs, as demonstrated by a strictly descending activation wavefront in the ipsilateral atrial wall, during pacing from the CSO and LLRA respectively. In addition, after ablation conduction time to the LLRA during pacing from the CSO increased from 52 +/- 16.62 before to 87 +/- 12.74 msec (p <.05), and to the CSO during pacing from the LLRA from 51 +/- 12.43 before to 79.50 +/- 9.85 msec (p <.05). Gross and histological examination of the TV-IVC isthmus after ablation revealed continuous transmural lesions, ranging from 3-5 mm in width, spanning the entire TV-IVC isthmus in all ten dogs. CONCLUSIONS: (1) Microwave ablation of the TV-IVC isthmus was safe and effective in this study. (2) Ablation of the entire width and thickness of the TV-IVC isthmus can be rapidly achieved using a long microwave antenna in a fixed trans-isthmus position.

Animals↗
PubMed1997

Spontaneous atrial flutter in a chronic canine model of the modified Fontan operation.

OBJECTIVES: This study sought to 1) establish whether the atrial flutter (AFL) inducible acutely occurs spontaneously in a chronic canine model, and 2) characterize any reentrant circuits present chronically. BACKGROUND: We previously demonstrated, in an acute canine model of the modified Fontan operation, that the lateral tunnel suture line creates a sufficient electrophysiologic substrate for AFL. METHODS: Using cardiopulmonary bypass, a suture line was placed through a right atriotomy in adult dogs (n = 7) to simulate the lateral tunnel of the Fontan operation. Holter recordings were made preoperatively, on the first postoperative day and 2, 4 and 6 weeks postoperatively. At 6 to 8 weeks, through bilateral ventriculotomies, 253-point unipolar atrial electrodes were inserted. AFL was induced using atrial burst pacing, and endocardial activation sequence maps were created. RESULTS: Preoperatively, all dogs were in sinus rhythm. Spontaneous AFL occurred in all dogs postoperatively, with a mean (+/-SD) cycle length of 192 +/- 22 ms. At 6 weeks postoperatively, of six dogs that survived, four had intermittent AFL, and two had incessant AFL. At reoperation, sustained AFL was inducible in six of six dogs, with a mean cycle length of 194 +/- 17 ms. Activation sequence maps demonstrated conduction block at the lateral tunnel suture line, which facilitated unidirectional conduction critical for propagation of the reentrant circuit. The AFL circuit was similar to that observed acutely. CONCLUSIONS: In a chronic canine model of the modified Fontan operation, the lateral tunnel suture line alone, in the absence of atrial stretch or hypertension, provides an electrophysiologic substrate that promotes spontaneous AFL. This model may be useful for evaluating various forms of treatment and prevention of AFL after the Fontan operation.

Animals↗
PubMed2005

Impact of congestive heart failure and left ventricular systolic function on the prognostic significance of atrial fibrillation and atrial flutter following acute myocardial infarction.

BACKGROUND: Reports on the prognostic importance of atrial fibrillation following myocardial infarction have provided considerable variation in results. Thus, this study examined the impact of left ventricular systolic function and congestive heart failure on the prognostic importance of atrial fibrillation in acute myocardial infarction patients that might explain previous discrepancies. METHODS: The study population was 6676 patients consecutively admitted to hospital with acute myocardial infarction. Information on the presence of atrial fibrillation/flutter, left ventricular systolic function and congestive heart failure were prospectively collected. Mortality was followed for 5 years. RESULTS: In patients with left ventricular ejection fraction<0.25, atrial fibrillation/atrial flutter was associated with an increased in-hospital mortality (OR=1.8 (1.1-3.2); p<0.05) but not an increased 30-day mortality. In patients with 0.25 0.35. In patients with congestive heart failure, atrial fibrillation/atrial flutter was associated with an increased in-hospital mortality (OR=1.5 (1.2-1.9); p<0.001) and increased 30-day mortality (OR=1.4 (1.1-1.7); p<0.001) but not in patients without congestive heart failure. In hospital survivors, atrial fibrillation/atrial flutter was associated with an increased long-term mortality in all subgroups except those with left ventricular ejection fraction<0.25. CONCLUSIONS: Atrial fibrillation/atrial flutter is primarily associated with increased in-hospital mortality in heart failure patients. Long-term mortality is increased in all subgroups except those with left ventricular ejection fraction<25%.

Aged↗
PubMed1989

Efficacy and safety of flecainide acetate in the maintenance of sinus rhythm after electrical cardioversion of chronic atrial fibrillation or atrial flutter.

The efficacy and safety of flecainide were studied in the maintenance of sinus rhythm after electrical cardioversion for chronic atrial fibrillation or atrial flutter. Eighty-one patients were randomized to flecainide treatment or no treatment. Baseline characteristics of both groups were comparable. Compared to previous studies, patients could be classified as difficult-to-treat patients. Multiple regression analysis showed New York Heart Association class I for exercise tolerance (p = 0.0004) and flecainide treatment (p = 0.01) to be the main factors increasing the arrhythmia-free episode. However, Mantel-Cox lifetable analysis did not reveal significant differences between arrhythmia-free survival curves of both treatment groups. In the flecainide-treated group, 9% of patients experienced side effects, mostly related to negative dromotropic effects. The incidence of ventricular proarrhythmia in this group of patients was low. Thus, flecainide may be effective in postponing arrhythmia recurrence, even in difficult-to-treat patients. Caution should be excercised in treating patients with underlying conduction disturbances, sick sinus syndrome or characteristics favoring development of ventricular proarrhythmia.

Adolescent↗
PubMed2005

Radiofrequency ablation for common atrial flutter using an 8-mm tip catheter and up to 150 W.

The formation of bi-directional block in atrial flutter can be adversely affected by problems with the delivery of effective energy related to isthmus anatomy and contact. Higher energies can produce larger and more effective lesions. The optimum setting for power delivery using temperature controlled ablation has not been established, with the maximum reported being 100 W. This is a retrospective review of the first 50 new cases assessing the efficacy and safety of using temperature controlled (60-65 degrees C) flutter ablation with an 8mm tip electrode catheter and up to 150 W. All cases had either typical flutter alone (34%) or predominant flutter as the indication, no combined procedures were included. Acute procedural success was 94% and long-term success of 88%. Median number of ablations required was 11 (interquartile range 10-19), median procedure time 120 min (IQR 102-164), fluoroscopy time 22 min (IQR 17-36), radiation dose 17 Gy cm(2) (IQR 10-27), median number of lines 1 (IQR 1-2). Six patients achieved 150 W, but 42 achieved >100 W (median watts 142 W, IQR 104-147). Patients (12%) experienced an uncomplicated pop during the procedure. None experienced a significant complication. There were three late relapses. The setting of 150 W maximum delivered energy in temperature regulated ablation allowed higher energies (>100 W) to be delivered in most patients. This resulted in acute and long-term success rates that compare well with the literature but is associated with a 12% rate of pop. Subsequent to this series our 54th patient sustained a pop due to high energy ablation that resulted in perforation and tamponade, from which there was survival.

Atrial Flutter↗
PubMed2000

Acute management of atrial fibrillation and atrial flutter in the critical care unit: should it be ibutilide?

BACKGROUND: Ibutilide is currently indicated for the rapid conversion of atrial fibrillation (Afb) or atrial flutter (Afl) of recent onset but limited to patients who are hemodynamically stable and without symptomatic cardiovascular conditions. HYPOTHESIS: The study was undertaken to assess the efficacy and safety of ibutilide in patients with Afb or Afl associated with acute cardiovascular-medical disorders and in patients receiving prior selective antiarrhythmic drug therapy. METHODS: The study included 34 patients, mean age 75 +/- 16.3 years, with Afb (n = 25) or Afl (n = 9) having a variety of disorders, for example, congestive heart failure, unstable angina, borderline hypotension, respiratory failure, and chronic renal failure. Prior antiarrhythmic drugs consisted of propafenone (n = 5) or amiodarone (n = 3). Eligibility for cardioversion was established with appropriate anticoagulation or transesophageal echocardiography findings. Ibutilide was given as up to two 10 min infusions of 1 mg separated by 10 min. RESULTS: The overall conversion rate after ibutilide was 79.4% (27/34 patients): 80% for Afb and 78% for Afl. More than 90% converted within 1 h of treatment. A high conversion rate of 92% resulted in those with an arrhythmia duration of < or = 1 week. All eight patients with prior antiarrhythmic therapy converted to sinus rhythm. The average baseline QTc interval for all patients increased 17.1% (397 +/- 63.3 to 465 +/- 60.2 ms) at 30 min. For eight patients (including four who received prior antiarrhythmic drugs), QTc interval prolongation > or = 500 ms was associated with nearly half the entire incidence of arrhythmic events. Proarrhythmia, the exclusive adverse effect, consisted of ventricular extrasystoles (n = 10) and nonsustained monomorphic ventricular tachycardia (VT) (n = 2) managed with intravenous MgSO4, and sustained polymorphic VT (n = 1) requiring electrical cardioversion. CONCLUSION: Ibutilide is an effective and well tolerated drug for the rapid termination of Afb or Afl of recent onset associated with symptomatic and/or hemodynamically unstable disorders, and it is most efficacious (> or = 90%) when the atrial arrhythmia is < or = 1 week in duration. Proarrhythmic events are readily manageable in a monitored unit with access to appropriate treatment.

Adult↗