The Atrial Natriuretic Peptide-to-brain Natriuretic Peptide Ratio Predicts Left Atrial Reverse Remodeling after Rhythm Control Therapy in Patients with Persistent Atrial Fibrillation.

Objective The association between natriuretic peptide levels in atrial fibrillation (AF) patients with advanced left atrial (LA) remodeling and reverse remodeling after rhythm control therapy has not been clarified. The present study assessed the role of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) measurements to predict LA reverse remodeling after catheter ablation (CA) in persistent AF patients with LA enlargement. Methods This study included 88 persistent AF patients with LA enlargement (volume index >48 mL/m2) who underwent CA. Plasma ANP and BNP levels were analyzed before CA in all patients. The study population was divided into 2 groups according to the extent of decrease in the LA volume index (LAVI) at 6 months after CA responders were those with a ≥15% reduction in the LAVI, and all others were non-responders. Results At follow-up, 58 patients (66%) were classified as responders. The preprocedural ANP level was significantly higher in the responders than in the non-responders (p=0.03). Furthermore, the ANP-to-BNP ratio (ANP/BNP) was significantly higher in the responders than in the non-responders (p<0.01). The ANP/BNP was correlated with the percentage decrease in the LAVI (r=0.391, p<0.01). A multivariate linear regression analysis revealed that the ANP/BNP before CA was an independent predictor of LA reverse remodeling (p<0.01). Conclusion The preprocedural ANP/BNP was a robust predictor of reverse remodeling of the enlarged LA after sinus rhythm restoration by rhythm control therapy in persistent AF patients.

Japan ablation registry: cryoablation in atrioventricular nodal reentrant tachycardia ("JARCANRET study"): results from large multicenter retrospective investigation.

PURPOSE: Cryoenergy has been demonstrated to be a safe alternative to radiofrequency ablation for catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). This study aimed to evaluate the safety and efficacy of cryoablation in patients with AVNRT. METHODS: A multicenter retrospective study was performed. Two hundred eighty-three consecutive patients with AVNRT underwent cryoablation. Cryomapping at - 30 °C and - 80 °C was performed to predict cryoablation outcome and ascertain antegrade conduction. Cryoenergy was delivered subsequently at the same spot (cryoablation at - 80 °C) for 240 s. RESULTS: Ablation procedure was acutely successful in 281 out of 283 patients (99.3%). Of note, 22 patients (10.1%) had transient AV block during the cryoablation, but no injurious effects on AV conduction were provoked during cryomapping. During a follow-up period of 367 ± 35 days, the recurrence rate was 3.9% (11 out of 281). There were no significant differences among the patients with a complete elimination of slow pathway conduction, AH jump without an echo beat, and AH jump with a single echo beat, in terms of the long-term recurrence of AVNRT. CONCLUSIONS: Cryoablation of AVNRT appears to be effective both acutely and during the long-term with a minimal risk of unwanted injuries to the conduction system. It seems to be important to monitor the antegrade conduction during cryoenergy applications, even when cryomapping demonstrates a safe location for cryoablation. The recurrence rate of AVNRT did not differ according to the properties of the residual slow pathway conduction.

Aortic Regurgitation Presenting with Recurrent Detachment of a Prosthetic Valve, as the First Presenting Symptom of Cardiovascular Behçet's Disease.

A 33-year-old man with severe aortic regurgitation underwent initial aortic valve replacement (AVR). During the 2 years after AVR, 3 reoperations for prosthetic valve detachment were required. During hospitalization, he had no typical clinical findings, with the exception of a persistent inflammatory reaction; a pseudo-aneurysm around the Bentall graft developed 27 days after the 4th operation. This unique clinical course suggested the possibility of Behçet's disease. In the 8 years of follow-up after the administration of prednisolone, the pseudo-aneurysm did not become enlarged and the detachment of the prosthetic valve was not observed. We herein present a case of cardiovascular Behçet's disease, with a review of the literature.

Extracardiac Interatrial Tunnel and Atrial Septal Defect Closed With a Single Atrial Septal Occluder in an Adolescent Girl.

In contrast to the atrial septal defect (ASD) as a congenital interatrial shunt, the extracardiac interatrial tunnel is extremely rare. We report the first percutaneous closure of this entity during closure of a secundum ASD after careful investigation of ischemic risk in a 15-year-old girl. The extracardiac interatrial tunnel could entail interatrial shunt, and, if misidentified as an ASD, could result in lethal procedural complications during surgical or catheter interventions. In our case, the tunnel was also morphologically similar to the cardiac arterial/venous system. Therefore, careful investigation of its potential relationship with coronary circulation was required before its closure.

Ventricular tachyarrhythmia associated with hypertrophic cardiomyopathy: incidence, prognosis, and relation to type of hypertrophy.

OBJECTIVE: To assess the incidence, characteristics, and prognosis of ventricular tachyarrhythmia in hypertrophic cardiomyopathy (HCM). PATIENTS: The study consisted of 66 consecutive patients with HCM who were admitted to Niigata University Hospital between 1992 and 2005. Their clinical characteristics and ECG morphology were investigated according to the type of HCM. RESULTS: The type of HCM was asymmetric hypertrophy (ASH) in 34 patients (51%), obstructive HCM (HOCM) in 9 (14%), apical HCM (ApHCM) in 14 (21%), and midventricular obstruction (MVO) in 9 (14%). The cause of admission was ventricular tachyarrhythmia in 25 patients (38%), unexplained syncope in 11 (17%), and heart failure in 30 (45%). Sustained monomorphic ventricular tachycardia (SMVT) occurred in 19 patients and ventricular fibrillation in 6. In the 19 patients with SMVT, 12 had MVO and 3 of these had previous apHCM. Six of the 19 patients with SMVT had ASH, and 3 had abnormal apical wall motion. In 14 patients, the SMVT appeared to originate from the apical aneurysm based on the morphology of the tachycardia. Ventricular tachyarrhythmia recurred in 14 of the 25 patients (56%), and 4 of the 18 patients with an ICD had electrical storm. ASH with abnormal wall motion of the LV apex or MVO was recognized in the 4 patients with electrical storm; they commonly had abnormal Q waves and ST elevation in leads V4-V6. CONCLUSION: Ventricular tachyarrhythmia was responsible for 38% of hospitalizations in HCM, and SMVT occurred in patients with MVO and/or with abnormal wall motion of the LV apex. Electrical storm was more common in patients with ST elevation in precordial leads V4-V6.

Effects of bepridil versus E-4031 on transmural ventricular repolarization and inducibility of ventricular tachyarrhythmias in the dog.

BACKGROUND: Bepridil (a multiple channel blocker) may markedly prolong the QT interval and induce polymorphic ventricular tachyarrhythmias (VTA). We compared the transmural ventricular repolarization characteristics and inducibility of polymorphic VTA after administration of bepridil versus the pure I(Kr) blocker, E-4031, each administered to five open-chest dogs. METHODS: We used plunge needle electrode to record transmural left ventricular (LV) repolarization and activation-recovery interval (ARI) to estimate local repolarization. The correlation between paced cycle length and ARI was separately examined in the LV endocardium, mid-myocardium (Mid), and epicardium. Attempts to induce VTA were made during bradycardia and sympathetic stimulation. RESULTS: Bepridil and E-4031 prolonged QT interval and ARI in all LV layers, though the magnitude of prolongation was greatest in Mid, increasing the transmural ARI dispersion, particularly during bradycardia. Compared with E-4031, bepridil caused mild, reverse use-dependent changes in ventricular repolarization, and less ARI dispersion than E-4031 during slow ventricular pacing. Both drugs increased ARI(max) and cycle length at 50% of ARI(max), though the changes were smaller after bepridil than after E-4031 administration. Bradycardia after the administration of each drug induced no VTA; however, sympathetic stimulation induced sustained polymorphic VTA in two of five dogs treated with E-4031 versus no dog treated with bepridil. CONCLUSIONS: Unlike the pure I(kr) blocker, E-4031, bepridil exhibited weak properties of reverse use-dependency and protected against sympathetic stimulation-induced VTA. It may be an effective supplemental treatment for recipients of implantable cardioverter defibrillator.

Effect of bepridil in atrial fibrillation inducibility facilitated by vagal nerve stimulation. - Prevention of vagal nerve activation-induced shortening of the atrial action potential duration -.

BACKGROUND: Because bepridil blocks multiple myocardial ionic channels, including the muscarinic acetylcholine receptor-operated potassium current (I(KAch)), bepridil is expected to suppress atrial fibrillation (AF) mediated by vagal nerve stimulation (VNS). METHODS AND RESULTS: The therapeutic effects of bepridil were studied with a special focus on heart rate variability (HRV) in a canine model of AF. During VNS, AF was induced in 9 of 9 experiments before, vs 3 of 9 experiments after administration of bepridil (P<0.01). During 350 ms atrial pacing, VNS shortened the right and left atrial monophasic action potentials at 90% repolarization (MAP90) by -31+/-8% and -22+/-12%, respectively, vs -10+/-13% and -6+/-8%, respectively, after bepridil (P<0.01, N=9). Bepridil prolonged the sinus cycle length, although it had no significant effect on the conduction time measured at 300 ms pacing. Statistically insignificant change was observed in the VNS-induced slowing of the sinus cycle length and in the VNS-induced increase in high frequency amplitude of HRV before (1.2+/-0.7 to 5.3+/-4.0 ms) vs after (1.7+/-0.8 to 5.4+/-2.3 ms) bepridil administration. CONCLUSIONS: Bepridil prevented the VNS-induced shortening of atrial MAP90 and suppressed the inducibility of AF during VNS in two-thirds of the experiments. As far as this study shows, it may be possible that inhibition of I(KAch) played a part in this antifibrillatory effect.

Correlation between surface and intracardiac electrocardiogram in a patient with inappropriate defibrillation shocks due to hyperkalemia.

A 39-year-old man received implantable cardioverter defibrillator (ICD) shocks during sinus rhythm, triggered by an increase in amplitude and oversensing of intracardiac T waves, caused by hyperkalemia. After treatment of hyperkalemia, the T wave morphology normalized, and oversensing and inappropriate ICD shocks were eliminated. Alteration of the intracardiac electrogram was well correlated to the surface electrocardiogram (ECG) changes. Intracardiac T waves can be altered by hyperkalemia and it seems that this alteration can be estimated by surface ECG analysis.

Ventricular repolarization gradients in a patient with takotsubo cardiomyopathy.

A 61-year-old woman had recurrent syncopal attacks caused by torsades de pointes associated with remarkable QT prolongation (QTc = 740 ms). Left ventriculography showed apical akinesis (ballooning) and basal hyperkinesis, but coronary angiography was normal. This was compatible with takotsubo cardiomyopathy. The wall motion of the left ventricle (LV) normalized within 2 months, and the remarkable QT prolongation and negative T-waves gradually normalized. However, polymorphic ventricular tachycardia recurred at 2.5 months after its initial onset, and we measured repolarization gradients using activation recovery intervals (ARIs) in an electrophysiological study. During atrial pacing at a cycle length of 1000 ms, the negative T-waves were observed in leads II, III, aVF, and V2-6 with QT prolongation, and the ARIs in both the epicardium and the endocardium increased from the basal site to the apical site. Moreover, the ARI tended to be longer in the epicardium than the endocardium at each level of the LV. In contrast, atrial extrastimulation changed the T-wave morphology (from negative to biphasic) in leads II, III, aVF, and V2-6 and changed the ARI gradients both from the LV basal site to the apical site and from the epicardium to the endocardium. These results suggest that the T-wave abnormalities seen in takotsubo cardiomyopathy during sinus rhythm are due to abnormal LV repolarization gradients.

Knee-flexion torque and morphology of the semitendinosus after ACL reconstruction.

PURPOSE: The present study aimed to clarify the relationship between deficits in knee-flexion torque and morphological changes in the semitendinosus muscle-tendon complex after harvesting the semitendinosus tendon for anterior cruciate ligament (ACL) reconstruction. METHODS: Isometric knee-flexion torque at 45 and 90 degrees of knee flexion was measured in limbs of 23 patients (22 +/- 4 yr) who underwent unilateral ACL reconstruction (12-43 months postoperation) using ipsilateral semitendinosus tendon. Magnetic resonance imaging scans were used to calculate the muscle volume and the muscle length of the semitendinosus and to confirm the presence of the regenerated semitendinosus tendon. RESULTS: The percentage of the knee-flexion torque of the ACL-reconstructed limb compared with that of the contralateral limb was lower at 90 degrees than at 45 degrees . The regeneration of the semitendinosus tendon-like structure was confirmed in 21 of the 23 patients. However, muscle volume and muscle length of the semitendinosus in the ACL-reconstructed limb were significantly smaller compared with in the contralateral limb. CONCLUSION: Deficits in knee-flexion torque at deep knee flexion were associated with the atrophy and shortening of the semitendinosus after harvesting the semitendinosus tendon for ACL reconstruction.