Results from the Loire-Ardèche-Drôme-Isère-Puy-de-Dôme (LADIP) trial on atrial flutter, a multicentric prospective randomized study comparing amiodarone and radiofrequency ablation after the first episode of symptomatic atrial flutter.

BACKGROUND: There is no published randomized study comparing amiodarone therapy and radiofrequency catheter ablation (RFA) after only 1 episode of symptomatic atrial flutter (AFL). The aim of the Loire-Ardèche-Drôme-Isère-Puy-de-Dôme (LADIP) Trial of Atrial Flutter was 2-fold: (1) to prospectively compare first-line RFA (group I) versus cardioversion and amiodarone therapy (group II) after only 1 AFL episode; and (2) to determine the impact of both treatments on the long-term risk of subsequent atrial fibrillation (AF). METHODS AND RESULTS: From October 2002 to February 2006, 104 patients (aged 78+/-5 years; 20 women) with AFL were included, with 52 patients in group I and 52 patients in group II. The cumulative risk of AFL or AF was interpreted with the use of Kaplan-Meier curves and compared by the log-rank test. Clinical presentation, echocardiographic data, and follow-up were as follows: age (78.5+/-5 versus 78+/-5 years), history of AF (27% versus 21.6%); structural heart disease (58% versus 65%), left ventricular ejection fraction (56+/-14% versus 54.5+/-14%), left atrial size (43+/-7 versus 43+/-6 mm), mean follow-up (13+/-6 versus 13+/-6 months; P=NS), recurrence of AFL (3.8% versus 29.5%; P<0.0001), and occurrence of significant AF beyond 10 minutes (25% versus 18%; P=0.3). Five complications (10%) were noted in group II (sick sinus syndrome in 2, hyperthyroidism in 1, and hypothyroidism in 2) and none in group I (0%) (P=0.03). CONCLUSIONS: RFA should be considered a first-line therapy even after the first episode of symptomatic AFL. There is a better long-term success rate, the same risk of subsequent AF, and fewer secondary effects.

Cavotricuspid isthmus angiography predicts atrial flutter ablation efficacy in 281 patients randomized between 8 mm- and externally irrigated-tip catheter.

AIMS: Radiofrequency ablation (RFA) of cavotricuspid isthmus (CTI)-dependent atrial flutter can be performed using various types of ablation catheters. Recent evaluations comparing externally cooled-tip RFA (ecRFA) catheters and large-tip (8 mm) catheters found that ecRFA catheter may have a higher efficacy for CTI ablation. The aim of this prospective study was to compare both catheters by stratifying on CTI morphology in order to explain, in part, the discrepancies between previous randomized studies, and to validate predictive factors of difficult CTI ablation on clinical, echocardiographic, and angiographic data. METHODS AND RESULTS: Over a period of 24 months, 281 patients were included and stratified on CTI morphology: 'straight', 'concave', and 'pouch-like recess'. In straight CTI (n=150), the duration of application time with a median of 6 min [interquartile range (IQR) 4-9] vs. a median of 12 min (IQR 16-19; P<0.0001) and the duration of X-ray exposure with a median of 6 min (IQR 4.4-9.7) vs. a median of 10.4 min (IQR 7-17; P<0.0001) were significantly lower with an 8 mm-tip when compared with ecRFA catheter. In contrast, in concave CTI (n=95), a trend towards both shorter application time with a median of 12.5 min (IQR 6-23) vs. a median of 19 min (IQR 7-28; P=0.08) and X-ray duration exposure with a median of 10.4 min (IQR 6-20) vs. a median of 13 min (IQR 8-24; P=0.08) with an ecRFA catheter when compared with 8 mm-tip catheter were evidenced. No significant difference was shown between 8 mm-tip and ecRFA catheters in the pouch-like recess group (n=36). Predictive factors of difficult ablation include right CTI length and morphology. CONCLUSION: This study demonstrates that the 8 mm-tip catheter is more effective for ablation in case of a straight angiographic isthmus morphology and that the ecRFA catheter tends to be more effective in case of concave angiographic isthmus morphology. Thus, angiographic isthmus evaluation may predict both the effectiveness of an RF catheter, and the risk of an expensive crossover. These data may explain, in part, the discrepancies of previous studies comparing both catheters.

Long-term efficacy and safety of radiofrequency ablation in elderly patients with atrioventricular nodal re-entrant tachycardia.

AIMS: The purpose of this study was to evaluate the efficacy, risks, safety, and follow-up of radiofrequency (RF) catheter ablation of atrioventricular nodal re-entrant tachycardia (AVRNT) in patients (pts) > or = 75 years old (n=42) (GpI) compared with pts younger than 75 years (n=234) (GpII). METHODS AND RESULTS: The study population consisted of 276 consecutive pts (39.5% men/60.5% women), from 15 to 98-year-old (average 56+/-17 years) with AVRNT referred for RF ablation (RFA) from October 1997 to January 2004. Combined anatomical and electrogram approaches were used to guide RFA. The cumulative risk of AVRNT recurrence was analysed by the Kaplan-Meier method and log-rank test. The average follow-up was 34+/-18 months. GpI (80+/-4 years) differed significantly from GpII (51+/-14 years) regarding: heart rate tachycardia (160+/-20 vs. 180+/-30 bpm; P=0.0001), the slow pathway antegrade refractory period (370+/-70 vs. 340+/-60 ms; P=0.01), the fast pathway antegrade refractory period (360+/-60 vs. 330+/-60 ms; P=0.003), retrograde refractory period (360+/-60 vs. 330+/-60 ms; P=0.0007), left ventricular ejection fraction (60+/-12 vs. 65+/-7%; P=0.0009), and ischaemic ECG signs during tachycardia (76.2% vs. 61%; P=0.09). RFA was successfully obtained in 275/276 (99.6%), 42/42 in GpI (100%), and 233/234 (99.6%) in GpII. Five complications occurred (1.8%): major complications in two pts (0.7%) and minor complications in three pts (1.1%). Major complications were deep venous thrombosis with pulmonary embolus (n=1) and pericardial effusion (n=1), minor complications were groin haematoma (n=3). One complication was observed in GpI (groin haematoma) (2.4%) and four in GpII (deep venous thrombosis with pulmonary embolus in one, groin haematoma in two, and pericardial effusion in one) (1.7%). The number of recurrences was not statistically different between the two groups (0 vs. 3.4%; P=0.5) with a respective average follow-up of 28+/-18 and 35+/-18 months, respectively. CONCLUSION: Catheter ablation of AVRNT in elderly and very elderly pts appears to be a reasonable approach regarding feasibility and effectiveness without increasing the risk of AV block.

Prospective validation of stress echocardiography as an identifier of cardiac resynchronization therapy responders.

BACKGROUND: Cardiac resynchronization therapy (CRT) provides benefit for congestive heart failure (CHF), but predictors of the clinical response are debated. OBJECTIVE: The aim of this prospective study was to assess the predictive role of dobutamine stress echocardiography (DSE) in identifying a suitable candidate for CRT. METHODS: From March 2001 to December 2003, 71 CHF patients were prospectively enrolled on the basis of four criteria: New York Heart Association (NYHA) class III and IV; QRS > or =150 ms with a left bundle branch block pattern, and left ventricular ejection fraction (LVEF) < or =35% under optimal medical treatment. The combined endpoints were hospital readmission for class IV CHF, heart transplant (HT), and CHF-related death. RESULTS: The 67 patients completing the study presented with the following characteristics: age (70 +/- 10 years; 11 women); etiology (idiopathic in 44, ischemic in 23); NYHA class (40 in class III and 27 in class IV); LVEF 26% (+/-5%); QRS duration (190 +/- 28 ms); 6-minute walk test 330 m (+/-108); peak oxygen uptake 10.7 (+/-3.3 mL/kg/min); mitral insufficiency in 42 (> or =III grade); interventricular (IV) delay (62 +/- 21 ms); and intraventricular dyssynchrony in 30 patients. Over the follow-up period of 12.1 +/- 8.7 months, 20 (29.9%) of 67 patients presented with at least one hemodynamic event: hospitalization for CHF in 19 (28%) of 67, HT in 2 (3%) of 67, and CHF death in 7 (10%) 67. Univariate analysis identified NYHA class (P = .03), LVEF (P = .015), IV dyssynchrony before (P = .038) and after CRT (P = .0035), IV delay after CRT (P = .002), 6-minute walk distance (P = .01), and DSE Res+ (P = .008) as significant predictors of clinical events. A receiver operating curve established a cut-off value of 1.25 for the DSE responders (Res+: 34 patients at 10 microg/kg/min infusion rates), and the improvement at the 10 microg/kg/min level was 41% +/- 7% in Res+ and 29% +/- 8% in nonresponders (P<.0001). With a cut-off value of 1.25-fold the LVEF increase, the DSE test exhibits 70% sensitivity, 61.7% specificity, 43.8% positive predictive value, and 82.9% negative predictive value. Cox analysis identified IV dyssynchrony before CRT (P = .01) and DSE Res+ (P = .003) as independent predictive factors. CONCLUSIONS: Independent predictive factors of severe hemodynamic clinical outcome in patients with CRT are IV dyssynchrony and DSE.

Catheter selection for ablation of the cavotricuspid isthmus for treatment of typical atrial flutter.

Radiofrequency catheter ablation (RFA) represents the first line therapy of the cavotricuspid isthmus-dependent atrial flutter (CTI-AFL) with a high efficacy and low secondary effects. RFA of CTI-dependent AFL can be performed by using various types of ablation catheters. Recent evaluations comparing externally cooled tip RFA (ecRFA) catheters and large-tip (8 mm) catheters have revealed that these catheters have a higher efficacy for CTI-AFL ablation compared to 4-mm catheters. The reliability of RFA catheters for AFL is variable and an optimal catheter selection may enhance the RFA effectiveness. The main goal of this article is to review the elements that improve the management of CTI RFA. Preliminary examinations of histopathologic and anatomical elements that may interfere with conventional CTI RFA are presented. Experimental studies concerning the electrobiology of large-tip and cooled-tip catheters are compared. The different catheter designs between cooled-tip and 8-mm-tip catheters are examined (size of the deflectable curve, rotation stability, and size of the distal nonsteerable catheter part) because of their critical role in CTI RFA results. A thorough review of clinical trials of each catheter is presented, and comparison of both catheters in this clinical setting is analyzed. In addition, the role of CTI morphology on AFL RF duration is underlined such as the value of right atrial angiography as an adjunct tool for CTI RFA catheter selection. Based on randomized studies, 8-mm-tip catheters seem to be more effective for ablation in case of straight angiographic isthmus morphology. On the other hand, ecRFA catheters appear to be more effective in cases of complex CTI anatomy or difficult CTI RFA. To reduce X-ray exposition and RFA application time, few studies report that CTI angiographic evaluation before RFA allows a catheter selection based on both CTI morphology and length. Moreover, preliminary data of randomized studies showed that an angiographic isthmus evaluation may predict both the effectiveness of a RFA catheter and the risk of an expensive catheter crossover.

Simplified cardiac resynchronization implantation technique involving right access and a triple-guide/single introducer approach.

BACKGROUND: Biventricular pacing is useful for patients with congestive heart failure but has the disadvantage of being a long, user-dependent, highly technical procedure. OBJECTIVES: The purpose of this study was to simplify the procedure. The simplified technique consists of sinus (CS) venography prior to implantation, direct coronary access for the left ventricular (LV) lead without use of a left-heart delivery system, and triple-guide/one introducer cephalic vein access as the first approach in patients presenting in sinus rhythm. METHODS: A cephalic cutdown was performed, and a steerable hydrophilic guidewire was introduced in the cephalic vein. A 9Fr introducer was advanced over the guidewire, and two other guides were inserted through the introducer. This technique allowed for insertion of a right ventricular lead, an LV lead, and an atrial lead. RESULTS: One hundred three patients were evaluated from January 2002 to September 2004. Four implants failed (3.9%). The 7Fr LV lead was successfully placed in 99 of 103 patients (96.1%) directly via the 9Fr introducer, without use of a dedicated left-heart delivery system. The final position was lateral in 59 patients, posterolateral in 33, posterior in 4, and anterolateral in 3. Sixty patients were in sinus rhythm, 13 were in atrial fibrillation, and 26 had a previous pacemaker (n = 21) or defibrillator (n = 5). Triple cephalic vein access was possible in 48 of the patients in sinus rhythm (80%). Procedure parameters were as follows: LV threshold 0.9 +/- 0.7 V, LV wave amplitude 15 +/- 8 mV, LV impedance 790 +/- 232 Omega, skin-to-skin procedure time 76 +/- 33 minutes, and fluoroscopy time 23 +/- 19 minutes. Ten complications (10.1%) occurred: 7 lead dislodgments (3 within 48 hours and 4 within 6 months) requiring repositioning (7.1%), 1 subacute local infection requiring explantation (1%), 1 phrenic nerve stimulation (1%), and 1 pneumothorax (1%). The long-term success of biventricular pacing was 93.1%. CONCLUSIONS: This study demonstrates that cardiac resynchronization therapy implantation can be simplified with the combined use of a steerable hydrophilic guidewire, three guides, and one introducer via a right cephalic vein, without use of a left-heart delivery system. The triple cephalic vein approach yields an 80% implant success rate for patients in sinus rhythm. The long-term success of biventricular pacing was 93.1%.

Anatomic and electrophysiological differences between chronic and paroxysmal forms of common atrial flutter and comparison with controls:.

Whether chronic typical atrial flutter differs from paroxysmal atrial flutter regarding electrophysiological properties of reentry pathways and cardiac function remains unknown. If so, can remodeling due to long duration of persistently rapid atrial or ventricular rates explain these changes? The aim of the study was to compare RA local conduction velocities and heart function parameters between three groups: (1) chronic atrial flutter, (2) paroxysmal atrial flutter, and (3) controls. The study evaluated 52 patients undergoing radiofrequency ablation for typical atrial flutter. There were 35 patients with chronic atrial flutter (62.7 +/- 14 years) and 17 patients with paroxysmal atrial flutter (62.7 +/- 10 years). Underlying structural heart disease was present in 20 (57%) of 35 chronic atrial flutter patients and in 7 (41%) of 17 paroxysmal atrial flutter patients (P = 0.1). Chronic atrial flutter duration was 10.9 +/- 17 months and paroxysmal atrial flutter duration was 8.5 +/- 10 (P = 0.06). RA conduction velocity measurements were carried out before ablation during sinus rhythm under pacing (600-ms cycle length) with a 12-pole steerable catheter positioned in the high lateral RA (poles 11-12 [H6]), mid-lateral RA (poles 9-10 [H5]), and along the inferior vena caval tricuspid isthmus (poles 7-8 [H4]; 5-6 [H3]; 3-4 [H2]) with its distal electrode pair at the coronary sinus origin (pole 1-2 [H1]). Counter-clockwise RA conduction velocities were assessed from H6 to H1 and clockwise RA conduction velocities from H1 to H6. After successful ablation, RA and LA areas, LV volumes, LVEF, inferior vena caval tricuspid annulus, and coronary sinus tricuspid annulus (septal isthmus) lengths were measured by two-dimensional echocardiography. The control group included 12 patients without structural heart disease, referred for electrophysiological evaluation of AVN reentry. Counter-clockwise RA conduction velocities at the inferior vena caval tricuspid isthmus were lower in chronic atrial flutter than in paroxysmal atrial flutter (H4, 1.19 +/- 0.4 vs 1.89 +/- 1 m/s, P = 0.0051; H3, 1.14 +/- 0.4 vs 1.6 +/- 0.7 m/s, P = 0.0015; H2, 1.16 +/- 0.4 vs 1.53 +/- 0.5 m/s, P < 0.0056 and H1, 1.2 +/- 0.4 vs 1.5 +/- 0.4 m/s, P = 0.03, respectively). Counter-clockwise RA conduction velocities were identical at the high and mid-lateral RA. Counter-clockwise caval isthmus RA conduction velocities from H3 to H1 were significantly different between chronic atrial flutter and controls (H3, 1.14 +/- 0.4 vs 1.7 +/- 0.3 m/s, P = 0.0014; H2, 1.16 +/- 0.4 vs 1.83 +/- 0.4 m/s, P < 0.0001 and H1, 1.2 +/- 0.4 vs 1.94 +/- 0.4 m/s, P < 0.0001, respectively). A difference was found regarding clockwise isthmus RA conduction velocities between the two groups of atrial flutter and controls but not between chronic atrial flutter and paroxysmal atrial flutter. Respectively, chronic atrial flutter had greater RA and LA areas (24.5 +/- 5 vs 13 +/- 2 cm2; P < 0.0001 and 23 +/- 5 vs 16 +/- 3 cm2, P < 0.0001), LV end-systolic and end-diastolic volumes (50 +/- 25 vs 32 +/- 13 cm3, P = 0.0084 and 112 +/- 40 vs 85 +/- 25 cm3, P = 0.01), septal isthmus length (21 +/- 3 vs 13 +/- 2 mm, P < 0.0001), and inferior vena caval tricuspid isthmus length (39 +/- 6 vs 23 +/- 5 mm; P < 0.0001). Chronic common atrial flutter is characterized by more prolonged counter-clockwise conduction times and larger anatomic conduction pathways than the paroxysmal form, the causal relationship between electrophysiological and anatomic characteristics remains to be demonstrated.

Effect of isthmus anatomy and ablation catheter on radiofrequency catheter ablation of the cavotricuspid isthmus.

BACKGROUND: Cavotricuspid isthmus (CTI) characteristics are rarely documented when comparing catheters in radiofrequency ablation (RFA) of atrial flutter (AFL). Our objectives were (1) to evaluate the impact of CTI morphology and length on ablation procedures and (2) to compare the efficacy of an 8-mm-tip catheter with an irrigated cooled-tip RFA in the subgroup presumed to be more difficult to treat (with a long CTI, >35 mm). METHODS AND RESULTS: Over a period of 17 months, 185 patients accepted the protocol and underwent an isthmogram in preparation for RFA. Groups were classified according to CTI length and CTI morphology. RFA was performed with an 8-mm-tip catheter for patients with a short CTI, < or =35 mm (n=123), whereas randomization between an 8-mm-tip and a cooled-tip catheter applied to patients with a longer CTI, >35 mm (n=62). For long CTI, 32 patients were assigned to an 8-mm catheter and 30 patients to the cooled-tip RFA ablation group. In this subset, RF application (18.2+/-17 versus 19+/-13 minutes) and x-ray exposure (20.8+/-18 versus 18+/-13 minutes) did not differ between the 8-mm-tip and the cooled-tip procedures. Number of applications (9.9+/-11 versus 18.6+/-15 minutes; P<0.0001) and x-ray exposure (11.7+/-11 versus 19.5+/-16 minutes, P=0.0001) differed significantly between patients with short and long CTIs. Patients with short and straight CTIs required 3 times fewer RFA applications and shorter x-ray exposure compared with other CTI morphologies (pouch-like recesses and concave characteristics). CONCLUSIONS: The number of RF applications required for a complete isthmus block in long CTIs is not influenced by the choice between an 8-mm or cooled-tip catheter. Procedure parameters, however, are significantly influenced by CTI length and morphology. Pouch-like recesses and concave characteristics account for much longer ablation times at all CTI lengths.

Flecainide induced ventricular tachycardia (torsades de pointes).

This case report describes a 68-year-old woman presenting with flecainide induced syncope due to torsades de pointes (TP) ventricular tachycardia. Before TP onset, the QTc interval reached 680 ms without changes in QRS duration. None of the usual triggers were found. Prolongation of QT under flecaïnide is exceptional and the occurrence of TP without concurrent triggers has not been reported in the literature.