Masayoshi 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.

Does Location of Epicardial Adipose Tissue Correspond to Endocardial High Dominant Frequency or Complex Fractionated Atrial Electrogram Sites During Atrial Fibrillation

Background— Although increased epicardial adipose tissue (EAT) volume is known to be associated with increased prevalence of atrial fibrillation (AF), the exact mechanisms are unclear. Therefore, we investigated whether EAT locations were associated with high dominant frequency (DF) sites or complicated fractionated atrial electrogram sites during AF. Methods and Results— Three-dimensional reconstruction computed tomography images depicting EAT volumes (obtained by 320-detector-row multislice computed tomography) were merged with NavX-based DF and complicated fractionated atrial electrogram maps obtained during AF for 16 patients with paroxysmal AF and for 18 patients with persistent AF. Agreement between locations of the EAT, especially EAT surrounding the left atrium, and of high DF or complicated fractionated atrial electrogram sites was quantified. In addition, serum biomarker levels were determined. EAT surrounding the left atrium volumes was significantly greater in patients with persistent AF than in patients with paroxysmal AF (52.9 cm3 [95% CI, 44.2–61.5] versus 34.8 cm3 [95% CI, 26.6–43.0]; P=0.007). Serum high-sensitivity C-reactive protein and interleukin-6 levels were significantly higher in persistent AF patients than in paroxysmal AF patients (median high-sensitivity C-reactive protein, 969 ng/mL [interquartile range, 307–1678] versus 320 ng/mL [interquartile range, 120–660]; P=0.008; median interleukin-6, 2.4 pg/mL [interquartile range, 1.7–3.2] versus 1.3 [interquartile range, 0.8–2.4] pg/mL; P=0.017). EAT locations were in excellent agreement with high DF sites (&kgr;=0.77 [95% CI, 0.71–0.82]) but in poor agreement with complicated fractionated atrial electrogram sites (&kgr;=0.22 [95% CI, 0.13–0.31]). Conclusions— Increased EAT volume and elevation of inflammatory biomarkers are noted in persistent AF rather than paroxysmal AF patients. High DF sites are located adjacent to EAT sites. Thus, EAT may be involved in the maintenance of AF.

Prediction of the efficacy of pulmonary vein isolation for the treatment of atrial fibrillation by the signal-averaged P-wave duration

Background: The noninvasive methods for predicting a successful pulmonary vein isolation (PVI) have not been well described. The aim of this study was to assess the usefulness of the P‐wave signal‐averaged electrocardiogram (P‐SAECG) in predicting the chance of a successful PVI in patients with atrial fibrillation (AF).

Effect of Catheter Tip-Tissue Surface Contact on Three-Dimensional Left Atrial and Pulmonary Vein Geometries: Potential Anatomic Distortion of 3D Ultrasound, Fast Anatomical Mapping, and Merged 3D CT-Derived Images

Anatomic Distortion of 3D Mapping. Background: Although catheter tip‐tissue contact is known as a reliable basis for mapping and ablation of atrial fibrillation (AF), the effects of different mapping methods on 3‐dimensional (3D) map configuration remain unknown.

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.

Prevalence of prominent J waves in patients presenting with ventricular fibrillation without structural heart disease:A single-center study

Association between sudden cardiac arrest and early repolarization (QRS slurring in the inferolateral leads) has drawn recent attention. We retrospectively assessed the prevalence of electrocardiographic J waves in 19 men aged 46.5±13.7 years who, between 1979 and 2011, were resuscitated after cardiac arrest due to ventricular fibrillation. There was no structural heart disease in this group. The J wave is an elevation of the QRS-ST junction of at least 0.1mV from baseline in the inferior or lateral leads, manifested as QRS slurring or notching. Eleven patients (age, 37.3±13.9 years) showed J waves in the inferior leads (n=8) or in both the inferior and lateral leads (n=3). Brugada syndrome was diagnosed in 5 patients (age, 46.4±15.7 years). The QRS complex was normal in the remaining 3 patients (age, 44.3±9.5 years). Ventricular fibrillation was induced by programmed ventricular stimulation with up to 3 extrastimuli from the right ventricular apex or outflow tract in 7 of the 10 J-wave syndrome patients tested, in all 5 Brugada syndrome patients, and in all 3 patients with a normal electrocardiogram. There appears to be an increased prevalence of J-wave syndrome among patients with a history of idiopathic ventricular fibrillation.

Functional atrioventricular conduction block in an elderly patient with acquired long QT syndrome: elucidation of the mechanism of block.

The long QT syndrome (LQTS) is occasionally complicated by impaired atrioventricular (AV) conduction. This form of LQTS can manifest before birth or during neonatal life, and no previous report has demonstrated LQTS complicated by impaired AV conduction in elderly patient. This case report describes an elderly patient with an acquired form of LQTS who developed ventricular fibrillation that was successfully defibrillated during admission to the hospital. Electrophysiologic study demonstrated that HV interval was 38 milliseconds and QT interval was 635 milliseconds during sinus rhythm cycle length of 1167 milliseconds. 1:1 AV conduction was maintained to a pacing cycle length of 545 milliseconds with an AH interval of 144 milliseconds, HV interval of 44 milliseconds, and right ventricular monophasic action potential duration of 360 milliseconds. However, 2:1 HV block developed at a pacing cycle length of 500 milliseconds. Intravenous administration of mexiletine decreased the cycle length of developing HV block to 360 milliseconds.

Spatial and temporal variability of the complex fractionated atrial electrogram activity and dominant frequency in human atrial fibrillation

The presence of complex fractionated atrial electrograms (CFAEs) and high dominant frequencies (DFs) during atrial fibrillation (AF) have been demonstrated to be related to AF maintenance. Therefore, sequential mapping of CFAEs and DFs have been used for target sites of AF ablation. However, such mapping strategies are valid only if the CFAEs and DFs are spatiotemporally stable during the mapping procedure. We obtained spatially stable multi‐electrode recordings to assess the spatiotemporal stability of CFAEs and DFs.

Efficacy and feasibility of pericardial endoscopy by a subcutaneous approach.

We tested the efficacy and feasibility of percutaneous subxiphoid video pericardial endoscopy in five dogs. After percutaneous subxiphoid puncture, steerable 9F endoscope and 7F irrigated-tip catheters were advanced into the epicardial space. Epicardial vessels were visualized, and basal fat was distinguishable. Lesions created by the irrigated-tip catheter could be also appreciated on the epicardial surface. The endoscopic pericardial procedure was successful and may increase the efficacy and safety of epicardial irrigated radiofrequency catheter ablation.

Changes over time in echocardiographic variables and atrial electromechanical intervals after ablation for atrial fibrillation

Acute and mid‐term effects of ablation for atrial fibrillation (AF) on left atrial (LA) and left ventricular (LV) function and the atrial electromechanical interval are controversial.