Pulmonary Vein Stenosis After Catheter Ablation of Atrial Fibrillation Using a Cryoballoon, Hot Balloon, or Laser Balloon.

BACKGROUND: Pulmonary vein stenosis (PVS) after PV isolation (PVI) for atrial fibrillation (AF) is a severe complication that requires angioplasty. This study aimed to compare the reduction of the cross-sectional PV area (PVA) and the incidence of PVS after cryoballoon (CB)-PVI, hot balloon (HB)-PVI, or laser balloon (LB)-PVI.Methods and Results: A total of 320 patients who underwent an initial catheter ablation procedure for AF using a CB, HB, or LB in 2 hospitals were included. They underwent contrast-enhanced multidetector CT before and 3 months after the procedure. In all 4 PVs, the reduction in PVA was more significant in the LB group than in the CB or HB groups, respectively. Moderate (50-75%) and severe (>75%) PVS were observed in 5.3% and 0.5% of the PVs, respectively. Although moderate PVS was more frequently observed in the LB group than in the CB or HB groups (8.2%, 3.8%, and 5.0%; P=0.03), the incidence of severe PVS was similar in the LB, CB, and HB groups (0.3%, 0.5%, and 1.0%; P=0.46). Symptomatic PVS requiring intervention occurred in 1 (0.3%) patient. CONCLUSIONS: Although the reduction in cross-sectional PVA and the incidence of moderate PVS after LB-PVI was more significant than after CB-PVI or HB-PVI, it rarely led to severe PVS. Symptomatic PVS requiring intervention was rare after the balloon ablation of AF.

Using the pre-freezing technique results in a wider area of antral isolation during cryoballoon pulmonary vein isolation in patients with atrial fibrillation.

The "pre-freezing" technique was a method in which a fully inflated balloon after the start of freezing was pressed against the pulmonary vein (PV) during cryoballoon ablation and has been applied especially in large-size PVs. Of 556 patients who underwent cryoballoon ablation for atrial fibrillation (AF), the pre-freezing technique was applied to 48 patients. The resulting 2:1 propensity score-matched data set included 120 patients. Using the pre-freezing technique, all left-superior PVs, all left-inferior PVs, and 95% of right-superior PVs were successfully isolated. In most right-inferior PVs, complete sealing using the pre-freezing technique was challenging, and this technique was not applied. Procedure time was similar between the two groups. In the pre-freezing group, the percentage of the left atrial posterior wall isolated was larger (47.6 ± 10.3 vs. 42.8 ± 15.7%, P = 0.006), and the postoperative reduction of diaphragmatic compound motor action potentials tended to occur less frequently (2.5 vs. 12.5%, P = 0.07), and the reduction of the cross-sectional LSPV area was smaller (17.5 ± 12.2 vs. 27.2 ± 19.8%, P = 0.03) than the conventional group. The AF-free rate of the two groups was similar between the two groups (P = 0.15). The pre-freezing technique was a simple method that can isolate a wider surface area during cryoballoon PV isolation. While the postoperative AF recurrence was comparable, the postoperative reduction in the cross-sectional PV area was less than that of the conventional method, which may reduce the risk of PV stenosis.

Effect of air removal with extracorporeal balloon inflation on incidence of asymptomatic cerebral embolism during cryoballoon ablation of atrial fibrillation: A prospective randomized study.

Background: It was previously reported, based on a retrospective study, that preliminary removal of air bubbles in heparinized saline water with extracorporeal balloon inflation reduced the incidence of asymptomatic cerebral embolism (ACE). The present study aims to compare the incidence of ACE between a conventional and pre-inflation method during cryoballoon ablation in a prospective randomized controlled study. Methods: A total of 98 atrial fibrillation patients were enrolled and randomized into conventional and pre-inflation groups. Patients in the pre-inflation group received balloon massaging with preliminary extracorporeal balloon inflation in saline water before the cryoballoon was inserted into the body. Results: The baseline characteristics were similar between the two groups. Post-procedural 3-Tesla MRI revealed CE in 27.6% of patients. Symptomatic CE only occurred in two patients in the pre-inflation group. One patient had transient dysarthria and mild muscle weakness in one hand; the other patient complained of transient left upper limb weakness, left lower limb paresthesia and dysarthria. The incidence of ACE detected by cerebral MRI did not differ between the two groups to a statistically significant extent (conventional vs. pre-inflation; 22.9% vs. 29.2%; P = 0.49). In the multivariable analysis, eGFR was independently associated with the presence of ACE (odds ratio 0.95; 95% confidence interval 0.907-0.995; P = 0.03). Conclusion: In this prospective randomized study, the preliminary removal of air bubbles in heparinized saline water with extracorporeal balloon inflation had no impact on the incidence of ACE.

Very long term outcome after linear versus electrogram guided ablation for persistent atrial fibrillation.

The optimal ablation strategy for persistent atrial fibrillation (PsAF) remains to be defined. We sought to compare very long-term outcomes between linear ablation and electrogram (EGM)-guided ablation for PsAF. In a retrospective analysis, long-term arrhythmia-free survival compared between two propensity-score matched cohorts, one with pulmonary vein isolation (PVI) and linear ablation including roof/mitral isthmus line (LINE-group, n = 52) and one with PVI and EGM-guided ablation (EGM-group; n = 52). Overall, 99% of patients underwent successful PVI. Complete block following linear ablation was achieved for 94% of roof lines and 81% of mitral lines (both lines blocked in 75%). AF termination by EGM-guided ablation was accomplished in 40% of patients. Non-PV foci were targeted in 7 (13%) in the LINE-group and 5 (10%) patients in the EGM-group (p = 0.76). During 100 ± 28 months of follow-up, linear ablation was associated with superior arrhythmia-free survival after the initial and last procedure (1.8 ± 0.9 procedures) compared with EGM-group (Logrank test: p = 0.0001 and p = 0.045, respectively). In multivariable analysis, longer AF duration and EGM-guided ablation remained as independent predictors of atrial arrhythmia recurrence. Linear ablation might be a more effective complementary technique to PVI than EGM-guided ablation for PsAF ablation.

Long-term course of phrenic nerve injury after cryoballoon ablation of atrial fibrillation.

While phrenic nerve palsy (PNP) due to cryoballoon pulmonary vein isolation (PVI) of atrial fibrillation (AF) was transient in most cases, no studies have reported the results of the long-term follow-up of PNP. This study aimed to summarize details and the results of long-term follow-up of PNP after cryoballoon ablation. A total of 511 consecutive AF patients who underwent cryoballoon ablation was included. During right-side PVI, the diaphragmatic compound motor action potential (CMAP) was reduced in 46 (9.0%) patients and PNP occurred in 29 (5.7%) patients (during right-superior PVI in 20 patients and right-inferior PVI in 9 patients). PNP occurred despite the absence of CMAP reduction in 0.6%. The PV anatomy, freezing parameters and the operator's proficiency were not predictors of PNP. While PNP during RSPVI persisted more than 4 years in 3 (0.6%) patients, all PNP occurred during RIPVI recovered until one year after the ablation. However, there was no significant difference in the recovery duration from PNP between PNP during RSPVI and RIPVI. PNP occurred during cryoballoon ablation in 5.7%. While most patients recovered from PNP within one year after the ablation, PNP during RSPVI persisted more than 4 years in 0.6% of patients.

Clinical significance of early recurrence of atrial fibrillation after cryoballoon vs. radiofrequency ablation-A propensity score matched analysis.

OBJECTIVES: One of the mechanisms of early recurrence of atrial fibrillation (ERAF) after AF ablation is considered to be the inflammatory reaction of the atrial tissue. The aim of this study is to compare the clinical significance of ERAF at each stage for true AF recurrence between cryoballoon (CB) and radiofrequency (RF) ablation. METHODS: Among 798 paroxysmal AF patients who underwent an initial ablation, 460 patients (CB, n = 230; RF, n = 230) were selected by propensity score matching. Very ERAF (VERAF), ERAF-1M, ERAF-3M and true AF recurrence were defined as AF recurrence at 0-2, 3-30, 31-90 days and more than 90 days after the procedure, respectively. RESULTS: The patient characteristics of the two groups were similar. ERAF was observed 21% and 27% in the CB and RF groups, respectively. In both the CB and RF group, VERAF, ERAF-1M and ERAF-3M were more frequently observed in patients with true AF recurrence than in those without. In a multivariable analysis, ERAF-1M and ERAF-3M were found to be independent predictors of true AF recurrence in both the CB (P = 0.04 and P<0.001, respectively) and RF groups (P = 0.02 and P = 0.001, respectively). However, while VERAF was associated with true AF recurrence after RF ablation (P = 0.03), it was not associated with true AF recurrence after CB ablation (P = 0.19). CONCLUSION: The relationship between ERAF and true AF recurrence differed between the RF and CB ablation groups. While VERAF was associated with true AF recurrence after RF ablation, it was not a predictor of true AF recurrence after CB ablation.

Radiofrequency needle for transseptal puncture is associated with lower incidence of thromboembolism during catheter ablation of atrial fibrillation: propensity score-matched analysis.

Atrial fibrillation (AF) ablation requires transseptal puncture to access the left atrium. Recently, a radiofrequency (RF) needle was developed. The purpose of this study was to compare the incidence of MRI-confirmed acute cerebral embolism (ACE) during AF ablation procedures performed with RF needle versus mechanical needle transseptal puncture. This study consisted of 383 consecutive patients who underwent catheter ablation for AF that required transseptal puncture with mechanical or radiofrequency transseptal needles. Of those, 232 propensity score-matched patients (116 with each needle type) were included in the analysis. All patients had cerebral MRI performed 1 or 2 days after the procedure. Baseline characteristics were similar between the two groups. Total procedure time was significantly shorter in Group RF than Group non-RF (167 ± 50 vs. 181 ± 52 min, P = 0.01). ACE was detected by MRI in 59 (25%) patients. All patients with ACE were asymptomatic. Incidence of ACE was lower in Group RF than Group non-RF (19 vs. 32%, P = 0.02). B-type natriuretic peptide level was higher in the patients with ACE as compared to those without ACE (65.2 ± 68.7 vs. 44.7 ± 55.1 pg/ml, P = 0.02). In multivariable analysis, the use of RF needle and BNP level was related to the incidence of ACE (OR = 0.499, 95% CI 0.270-0.922, P = 0.03 and OR = 1.005, 95% CI 1.000-1.010, P = 0.03). Use of RF needle for transseptal puncture was associated with lower total procedure time and risk of ACE during catheter ablation of AF.

Atrial fibrillation diagnosed by a medical checkup is associated with a poor outcome of catheter ablation.

Atrial fibrillation (AF), especially asymptomatic cases, is often detected by medical checkups. We investigated the outcome of AF ablation in cases detected by medical checkups. We reviewed the data of 735 patients with AF (56 ± 10 years, paroxysmal: 441 patients) who underwent initial catheter ablation. All patients were divided into two groups based on their AF being diagnosed either by a medical checkup (group M) or not (group NM). AF was diagnosed by medical checkups in 263 (36%) patients. In Group M, the age was younger, time from the diagnosis to ablation shorter, left atrium dimension larger, and left ventricular ejection fraction lower than in Group NM. Male gender, persistent AF, and asymptomatic AF were more frequently seen in Group M than in Group NM. A mean of 13 ± 11 months after the initial ablation procedure, AF recurrence was more frequently observed in group M compared to group NM (P = 0.018). While the AF recurrence rate was similar in both groups in persistent AF patients (P = 0.87), it was more frequently observed in Group M than in Group NM in paroxysmal AF patients (P = 0.005). AF diagnosed by medical checkups was often associated with a worse outcome of catheter ablation, especially in paroxysmal AF patients.

Effect of air removal with extracorporeal balloon inflation on incidence of asymptomatic cerebral embolism during cryoballoon ablation of atrial fibrillation.

BACKGROUND: Asymptomatic cerebral embolism (ACE) is sometimes detected after cryoballoon ablation of atrial fibrillation. The removal of air bubbles from the cryoballoon before utilization may reduce the rate of ACE. OBJECTIVE: This study aims to compare the incidence of ACE between a conventional and a novel balloon massaging method during cryoballoon ablation. METHODS: Of 175 consecutive patients undergoing initial cryoballoon ablation of paroxysmal atrial fibrillation, 60 (34.3%) patients underwent novel balloon massaging with extracorporeal balloon inflation in saline water (group N) before the cryoballoon was inserted into the body. The remaining 115 (65.7%) patients underwent conventional balloon massaging in saline water while the balloon remained folded (group C). Of those, 86 propensity score-matched patients were included. RESULTS: The baseline characteristics were similar between the 2 groups. In group N, even after balloon massaging in saline water was carefully performed, multiple air bubbles remained on the balloon surface when the cryoballoon was inflated in all cases. Postprocedural cerebral magnetic resonance imaging detected ACE in 14.0% of all patients. The incidence of ACE was significantly lower in group N than in group C (4.7% vs 23.3%; P = .01). According to multivariable analysis, the novel method was the sole factor associated with the presence of ACE (odds ratio 0.161; 95% confidence interval 0.033-0.736; P = .02). CONCLUSION: Preliminary removal of air bubbles in heparinized saline water with extracorporeal balloon inflation reduced the incidence of ACE. Since conventional balloon massaging failed to remove air bubbles completely, this novel balloon massaging method should be recommended before cryoballoon utilization.

Incidence and Factors Associated With the Occurrence of Pulmonary Vein Narrowing After Cryoballoon Ablation.

BACKGROUND: In contrast with traditional radiofrequency ablation, little is known about the influence of cryoballoon ablation on the morphology of pulmonary veins (PVs). We evaluated the influence of cryoballoon ablation on the PV dimension (PVD) and investigated the factors associated with a reduction of the PVD. METHODS AND RESULTS: Seventy-four patients who underwent cryoballoon ablation for paroxysmal atrial fibrillation were included in the present study. All subjects underwent contrast-enhanced computed tomography both before and at 3 months after the procedure. The PVD (cross-sectional area) was measured using a 3-dimensional electroanatomical mapping system. Each PV was evaluated according to the PVD reduction rate (ΔPVD), which was calculated as follows: (1-post-PVD/pre-PVD)×100 (%). Ninety-two percent of the PVs (271/296) were successfully isolated only by cryoballoon ablation; the remaining 8% of the PVs required touch-up ablation and were excluded from the analysis. Mild (25%-50%), moderate (50%-75%), and severe (≥75%) ΔPVD values were observed in 87, 14, and 3 PVs, respectively, including 1 case with severe left superior PV stenosis (ΔPVD: 94%) in a patient who required PV angioplasty. In multivariable analysis, a larger PV ostium and lower minimum freezing temperature during cryoballoon ablation were independently associated with PV narrowing (odds ratio, 1.773; P=0.01; and odds ratio, 1.137; P<0.001, respectively). CONCLUSIONS: A reduction of the PVD was often observed after cryoballoon ablation for atrial fibrillation. A larger PV ostium and lower minimum freezing temperature during cryoballoon ablation were associated with an increased risk of PVD reduction.

Impact of deep sedation on the electrophysiological behavior of pulmonary vein and non-PV firing during catheter ablation for atrial fibrillation.

PURPOSE: Catheter ablation for atrial fibrillation is performed with and without deep sedation, which could affect the arrhythmogenic activity during the procedure. We investigated the impact of sedation on electrophysiological properties in patients with AF who underwent catheter ablation. METHODS: This study consisted of 255 consecutive patients with atrial fibrillation (229 males, persistent: 105 patients) who underwent a single-catheter ablation procedure. The patients were divided into the following two groups according to the depth of sedation during the procedure: group M (mild sedation with flunitrazepam in 138 patients) and group D (deep sedation with propofol in 117 patients). Peripheral oxygen saturation was continuously monitored via pulse oximetry throughout the procedure. RESULTS: A spontaneous dissociated pulmonary vein activity after pulmonary vein isolation occurred more frequently in group M than in group D (29.1 vs 15.7%, P < 0.01). Adenosine-induced dormant pulmonary vein conduction was more frequently observed in group M than in group D (19.2 vs 13.0% P = 0.01). There were no significant differences in the incidence of non-pulmonary vein triggers between groups M and D (15.2 vs 11.1%, P = 0.53). The atrial fibrillation recurrence rate following the single procedure did not differ between the two groups (29.0 vs 26.5%, in groups M and D, P = 0.85). CONCLUSIONS: Although deep sedation reduced the incidence of a dissociated pulmonary vein activity and dormant pulmonary vein conduction following pulmonary vein isolation, it did not affect the recurrence rate for atrial fibrillation after the procedure.

Gain-Sparsity and Symmetry-Forced Rigidity in the Plane.

We consider planar bar-and-joint frameworks with discrete point group symmetry in which the joint positions are as generic as possible subject to the symmetry constraint. We provide combinatorial characterizations for symmetry-forced rigidity of such structures with rotation symmetry or dihedral symmetry of order 2k with odd k, unifying and extending previous work on this subject. We also explore the matroidal background of our results and show that the matroids induced by the row independence of the orbit matrices of the symmetric frameworks are isomorphic to gain sparsity matroids defined on the quotient graph of the framework, whose edges are labeled by elements of the corresponding symmetry group. The proofs are based on new Henneberg type inductive constructions of the gain graphs that correspond to the bases of the matroids in question, which can also be seen as symmetry preserving graph operations in the original graph.

Influence of the concomitant use of heparin on the effects of warfarin during catheter ablation for atrial fibrillation.

Warfarin is widely used to perform catheter ablation for atrial fibrillation (AF). Heparin is usually administered during this procedure to prevent thromboembolic events, while protamine is used to reduce the incidence of bleeding complications. The purpose of this study was to investigate the influence of heparin and protamine administration on the effects of warfarin and its safety. The subjects included 226 AF patients (206 males, 54.9 ± 9.1 years, paroxysmal/persistent AF: 118/108) undergoing AF ablation with the discontinuation of warfarin administration over 2 days. Heparin was administered to achieve an activated clotting time (ACT) above 300 s during the procedure. Several parameters of the coagulation status, including the prothrombin time international normalized ratio (PT-INR) and ACT values, measured immediately before and after protamine infusion were compared. The mean value of PT-INR prior to ablation was 1.9 ± 0.6. At the end of the procedure, the mean ACT and PT-INR values were 348.0 ± 52.9 and 2.9 ± 0.7, respectively. Following the infusion of 30 mg of protamine, both the ACT and PT-INR values significantly decreased, to 159.6 ± 31.0 (p < 0.0001) and 1.6 ± 0.3 (p < 0.0001), respectively. No cases of symptomatic cerebral infarction were observed, although femoral hematomas developed in 17 (7.5 %) of the patients without further consequence. The concomitant use of heparin augments the effect of warfarin. Meanwhile, protamine administration immediately reverses both the ACT and PT-INR, indicating the applicability of protamine for AF ablation in patients under the mixed administration of heparin and warfarin.

Catheter ablation of persistent atrial fibrillation in a patient with cor triatriatum sinister demonstrating a total common trunk of the pulmonary vein.

A 57-year-old male with persistent atrial fibrillation (AF) was referred for catheter ablation. Multidetector computed tomography (MDCT) revealed that a membrane divided the left atrium into two chambers, thus indicating the presence of cor triatriatum sinister. A 3D image reconstructed by MDCT showed that the accessory atrium received the left common and the right side PVs, as if it were a total common trunk, and this then flowed into the main atrium. After isolation of the pulmonary vein and posterior wall from the left atrium, AF could not be induced by any programmed pacing. The patient has remained free from AF during the 1 year of follow-up.

Paradoxical responses to pacing maneuvers differentiating atrioventricular node reentrant tachycardia and junctional tachycardia.

A 40-year-old female presented at our hospital because of heart palpitations. During an electrophysiological study, atrioventricular (AV) conduction showed dual AV nodal physiology. Three types of supraventricular tachycardia (SVT) were induced. The initiation of SVT was reproducibility dependent on a critical A-H interval prolongation. An early premature atrial contraction during SVT repeatedly advanced the immediate His potential with termination of the tachycardia, indicating AV node reentrant tachycardia (AVNRT). However, after atrial overdrive pacing during SVT without termination of the tachycardia, the first return electrogram resulted in an AHHA response, consistent with junctional tachycardia. The mechanism of paradoxical responses to pacing maneuvers differentiating AVNRT and junctional tachycardia was discussed.

Predictors of ectopic firing from the superior vena cava in patients with paroxysmal atrial fibrillation.

PURPOSE: Although catheter ablation targeting the pulmonary vein (PV) is a well-known therapy for patients with paroxysmal atrial fibrillation (PAF), ectopic firings from the superior vena cava (SVC) can initiate PAF. The purpose of this study was to investigate predictors of SVC firing. METHODS: The subjects included 336 consecutive PAF patients (278 males, age 56.1 ± 10.8 years) undergoing atrial fibrillation (AF) ablation. The appearance of SVC firing was monitored throughout the procedure using a decapolar catheter with multiple electrodes to record electrograms of the coronary sinus and SVC. In addition to PV isolation, SVC isolation was performed only in patients with documented SVC firing. RESULTS: SVC firing was observed in 43/336 (12.8 %) of the patients, among whom complete isolation of the SVC was achieved in 40/43 (93 %) patients. A lower body mass index (BMI) (22.8 ± 2.8 vs 24.1 ± 3.1 kg/m(2), p = 0.007) and higher prevalence of prior ablation procedures (58 vs 18 %, p = 0.0001) were related to the presence of SVC firing. In a multivariate analysis, a lower BMI (p = 0.012; odds ratio 0.83, 95 % CI 0.72 to 0.96) and history of prior ablation procedures (p < 0.0001; odds ratio 5.37, 95 % CI 2.71 to 10.63) were found to be independent predictors of the occurrence of SVC firing. Among 96 patients undergoing repeat ablation procedures, less PV-left atrial re-conduction was observed in patients with SVC firing than in those without (2.7 ± 1.2 vs 3.2 ± 0.8, p = 0.02). CONCLUSIONS: The presence of SVC firing in patients with PAF is associated with a history of repeat ablation procedures and lower BMI values.

The role of successful catheter ablation in patients with paroxysmal atrial fibrillation and prolonged sinus pauses: outcome during a 5-year follow-up.

AIMS: Although patients with paroxysmal atrial fibrillation (AF) and prolonged sinus pauses [tachycardia-bradycardia syndrome (TBS)] are generally treated by permanent pacemaker, catheter ablation has been reported to be a curative therapy for TBS without pacemaker implantation. The purpose of this study was to define the potential role of successful ablation in patients with TBS. METHODS AND RESULTS: Of 280 paroxysmal AF patients undergoing ablation, 37 TBS patients with both AF and symptomatic sinus pauses (age: 62 ± 8 years; mean maximum pauses: 6 ± 2 s) were analysed. During the 5.8 ± 1.2 years (range: 5-8.7 years) follow-up, both tachyarrhythmia and bradycardia were eliminated by a single procedure in 19 of 37 (51%) patients. Repeat procedures were performed in 14 of 18 patients with tachyarrhythmia recurrence (second: 12 and third: 2 patients). During the repeat procedure, 79% (45 of 57) of previously isolated pulmonary veins (PVs) were reconnected to the left atrium. Pulmonary vein tachycardia initiating the AF was found in 46% (17 of 37) and 43% (6 of 14) of patients during the initial and second procedure, respectively. Finally, 32 (86%) patients remained free from AF after the last procedure. Three patients (8%) required pacemaker implantation, one for the gradual progression of sinus dysfunction during a period of 6.5 years and the others for recurrence of TBS 3.5 and 5.5 years after ablation, respectively. CONCLUSION: Catheter ablation can eliminate both AF and prolonged sinus pauses in the majority of TBS patients. Nevertheless, such patients should be continuously followed-up, because gradual progression of sinus node dysfunction can occur after a long period of time.

Cardiac tamponade as an independent condition affecting the relationship between the plasma B-type natriuretic peptide levels and cardiac function.

Plasma B-type natriuretic peptide (BNP) is finely regulated by the cardiac function and several extracardiac factors. Therefore, the relationship between the plasma BNP levels and the severity of heart failure sometimes seems inconsistent. The purpose of the present study was to investigate the plasma BNP levels in patients with cardiac tamponade and their changes after pericardial drainage. This study included 14 patients with cardiac tamponade who underwent pericardiocentesis. The cardiac tamponade was due to malignant diseases in 13 patients and uremia in 1 patient. The plasma BNP levels were measured before and 24-48 h after drainage. Although the patients reported severe symptoms of heart failure, their plasma BNP levels were only 71.2 ± 11.1 pg/ml before drainage. After appropriate drainage, the plasma BNP levels increased to 186.0 ± 22.5 pg/ml, which was significantly higher than that before drainage (P = 0.0002). In patients with cardiac tamponade, the plasma BNP levels were low, probably because of impaired ventricular stretching, and the levels significantly increased in response to the primary condition after drainage. This study demonstrates an additional condition that affects the relationship between the plasma BNP levels and cardiac function. If inconsistency is seen in the relationship between the plasma BNP levels and clinical signs of heart failure, the presence of cardiac tamponade should therefore be considered.

Improvement of atrioventricular conduction following catheter ablation of atrioventricular nodal reentry tachycardia in a patient with a prolonged PR interval.

We herein present the case of a 60-year-old male with narrow QRS tachycardia who had a remarkable PR prolongation during sinus rhythm. The tachycardia was diagnosed as a slow-fast atrioventricular nodal reentry tachycardia. Slow pathway ablation was performed after the confirmation of the presence of an antegrade fast pathway. Following the elimination of the slow pathway, the PR and atrio-His intervals became shortened from 470 and 420 to 170 and 120 ms, respectively. Moreover, the improvement of atrioventricular conduction after the slow pathway ablation lasted for at least 34 months.