Tatsuya Kofune

Impact of Biomarkers of Inflammation and Extracellular Matrix Turnover on the Outcome of Atrial Fibrillation Ablation: Importance of Matrix Metalloproteinase‐2 as a Predictor of Atrial Fibrillation Recurrence

MMP‐2 Predicts the Outcome of AF Ablation. Introduction: Although catheter ablation can effectively eliminate atrial fibrillation (AF), the progression of atrial remodeling increases the risk of recurrence. AF is associated with inflammation and subsequent myocardial fibrosis. We therefore examined the possibility of determining the postablation prognosis of patients with AF using biomarkers of inflammation and collagen turnover.

Intravenous Administration of Class I Antiarrhythmic Drug Induced T Wave Alternans in an Asymptomatic Brugada Syndrome Patient

A 53‐year‐old man with an abnormal ECG was referred to the Nihon University School of Medicine. The 12‐lead ECG showed right bundle branch block and saddleback‐type ST elevation in leads V1–V3 (Brugada‐type ECG). Signal‐averaged ECG showed positive late potentials. Double ventricular extrastimuli (S1: 500 ms, S2: 250 ms, S3: 210 ms) induced VF. Amiodarone (200 mg/day) was administered for 6 months and programmed ventricular stimulation was repeated. VF was induced again by double ventricular stimuli (S1: 600 ms, S2: 240 ms, S3: 170 ms). Intravenous administration of class Ic antiarrhythmic drug, pilsicainide (1 mg/kg), augmented ST‐T elevation in leads V1–V3, and visible ST‐T alternans that was enhanced by atrial pacing was observed in leads V2 and V3. Visible ST‐T wave alternans disappeared in 15 minutes. However, microvolt T wave alternans was present during atrial pacing at a rate of 70/min without visible ST‐T alternans. (PACE 2003; 26:1900–1903)

Anatomic and Electrophysiologic Differences between Chronic and Paroxysmal Atrial Flutter: Intracardiac Echocardiographic Analysis

Background : It remains unknown why atrial flutter (AFL) occurs as either a chronic or paroxysmal arrhythmia.

Wolff‐Parkinson‐White Syndrome Concomitant with Asymptomatic Brugada Syndrome

A 29‐year‐old man was referred for electrophysiological testing and radiofrequency ablation because of repeated episodes of palpitation over 2 years. A 12‐lead electrocardiogram during sinus rhythm showed manifest Wolff‐Parkinson‐White syndrome and during palpitation showed narrow QRS tachycardia at a rate of 213 beats/min. Following successful radiofrequency ablation of the left anterolateral accessory pathway, sustained atrial fibrillation was induced by atrial extrastimulation. Cibenzoline (2 mg/kg body weight) was injected to terminate atrial fibrillation. ST‐T segment elevation in the right precordial leads was observed following cibenzoline administration. Ventricular fibrillation was reproducibly induced by ventricular extrastimuli (S1: 600 ms, S2: 220 ms, S3: 210 ms). (PACE 2004; 27:109–111)

Atrial tachycardia in a patient with arrhythmogenic right ventricular cardiomyopathy/dysplasia

We describe a 49‐year‐old woman with atrial tachycardia (AT) and arrhythmogenic right ventricular cardiomyopathy/dysplasia. Cardiac magnetic resonance images showed a markedly dilated right atrium and right ventricle. Electroanatomical mapping showed that the AT originated from the right atrial appendage.

Upper turnaround point of the reentry circuit of common atrial flutter--three-dimensional mapping and entrainment study.

BackgroundAlthough the anterior and posterior boundaries of cavotricuspid isthmus-dependent atrial flutter (AFL) are reported to be located at the tricuspid annulus and sinus venosa region or crista terminalis, the exact upper turnaround point of the AFL circuit remains unclear. The aim of this study was to determine the upper turnaround site of the AFL circuit by means of three-dimensional (3D) mapping and entrainment pacing.MethodsSubjects were 21 patients with counter-clockwise AFL in whom high-density mapping of the high right atrium (RA) and superior vena cava (SVC) orifice was performed with an electroanatomical or non-contact mapping system. Entrainment pacing was performed around the SVC-RA junction.ResultsIn 20 of the 21 patients, the wavefront from the septal RA split into two wavefronts: one that traveled anterior to the SVC and another that traveled to the posterior RA where it was blocked. In the remaining patient, the wavefront from the septal RA split into two wavefronts: one that propagated through the anterior portion of the SVC orifice and another that propagated transversely across the posterior portion of the SVC orifice. The two wavefronts joined in the lateral RA. Entrainment pacing from the SVC-RA junction demonstrated that the anterior boundary was within the circuit in all patients, but the posterior boundary also constituted a circuit in four patients.ConclusionsWe surmise that the upper turnaround site of the AFL circuit is located in the anterior portion of the SVC-RA junction in the majority of patients with AFL.

Left bundle branch block-type ventricular tachycardia originating from the left ventricular septum in a patient with cardiac sarcoidosis

This case report describes a left bundle branch block (LBBB)-type ventricular tachycardia (VT) with a unique reentrant circuit in a patient with cardiac sarcoidosis. The VT morphology and pace mapping supported an exit site of the VT from the basal posterior right ventricle (RV) septum. Nonetheless, concealed entrainment was established by pacing from a septal left ventricular (LV) site recording a diastolic potential, opposite site to the RV site. A point ablation at that LV site could successfully terminate the VT, suggesting that a critical isthmus was located on the LV side of the interventricular septum despite the demonstration of an LBBB-type VT.

Effect of IKr Blocker Nifekalant on Atrial Action Potential Duration After Successful Internal Cardioversion of Chronic Atrial Fibrillation

Background: Chronic atrial fibrillation (AF) is characterized by a marked decrease in the atrial effective refractory period (ERP) and in the ERP adaptation to rate as well as a decrease in the atrial conduction velocity. Little information is available about the ionic mechanisms underlying AF in humans.

Full-motion two- and three-dimensional pulmonary vein imaging by intracardiac echocardiography after pulmonary vein isolation.

Background: The pulmonary veins (PVs) are topographically complex and motile, so angiographic visualization of the PVs anatomy is limited. An imaging technique that accurately portrays the pulmonary vein (PV) anatomy would be valuable during and after catheter ablation procedures.

Reproducible induction of atrioventricular nodal reentrant tachycardia with adenosine triphosphate.

A 29‐year‐old woman was referred for electrophysiological testing and radiofrequency ablation because of repeated episodes of palpitation of a 8‐year duration. The 12‐lead ECG during palpitations showed narrow QRS tachycardia at a rate of 160 beats/min. Dual AVN physiology according to electrophysiological criteria was not shown by single atrial extrastimulation and the tachycardia could not be induced. Slow/fast atrioventricular nodal reentrant tachycardia (AVNRT) was induced once by double atrial extrastimuli, but it was not reproducible. However, intravenous bolus injection of adenosine triphosphate (12.5 mg) during sinus rhythm led to reproducible initiation of slow/fast AVNRT. (PACE 2003; 26:2321–2323)