Mitsuru Takami

Dilated phase of hypertrophic cardiomyopathy caused by Fabry disease with atrial flutter and ventricular tachycardia.

We describe a case of a 60-year-old male with dilated phase of hypertrophic cardiomyopathy caused by Fabry disease. He was diagnosed to have a cardiac variant of Fabry disease by an enzyme assay and a right ventricular endomyocardial biopsy which revealed specific features of this disease and cardiac involvement was the sole manifestation. He has developed dilated cardiomyopathy with sustained atrial flutter and frequent non-sustained ventricular tachycardia requiring isthmus ablation and cardiac resynchronization therapy with defibrillator.

Upper turnover portion of the reentry circuit for typical and reverse typical atrial flutter.

Background: The posteromedial right atrium (PMRA) forms a block line during typical atrial flutter (AFL). However, whether upper turnover portion exists at the anterior or posterior superior vena cava (SVC) has not been determined.

A case of an ablation catheter entrapped in the pulmonary vein during atrial fibrillation ablation requiring open heart surgery for removal

Case Report A 64-year-old woman with a 3-year history of drug refractory paroxysmal atrial fibrillation was referred to our hospital for catheter ablation. Preprocedual echocardiography and enhanced computed tomography (CT) revealed no structural heart disease or anatomic anomalies (Figure 1A). Catheter ablation of the atrial fibrillation was performed under conscious sedation. Two 8.5-F long sheaths, an 8-F long sheath, and a 6-F short sheath were introduced percutaneously via the right femoral vein. A 6-F venous sheath was introduced via the right internal jugular vein. A decapolar electrode catheter was positioned in the right ventricular apex. A duodecapolar electrode catheter was advanced into the coronary sinus. A transseptal puncture was performed with the assistance of intracardiac echocardiography using a radiofrequency needle (Japan Lifeline, Tokyo, Japan). Three long sheaths were advanced into the left atrium through the same puncture site. Pulmonary vein (PV) and left atrial angiogram revealed no anatomic anomalies, and the sheaths were placed into the superior PVs. Two circular mapping catheters were positioned in the PVs. An ablation catheter (Thermocool Smart Touch, Biosense Webster, Diamond Bar, CA) was inserted into the 8.5-F sheath placed in the right superior PV. The ablation catheter was pulled back and moved to start the ablation. The operator intended to place the ablation catheter into the left PV and pushed the

Rate-Dependent and Site-Specific Conduction Block at the Posterior Right Atrium and Drug Effects Evaluated Using a Noncontact Mapping System in Patients with Typical Atrial Flutter

Functional Block in the Posterior Right Atrium. Introduction: Conduction block in the posterior right atrium (RA) plays an important role in perpetuating atrial flutter (AFL). Although conduction blocks have functional properties, it is not clear how the block line changes with the pacing rate, pacing site, and administration of antiarrhythmic drugs.

Heparin bridging increases the risk of bleeding complications in patients undergoing anticoagulation therapy and device implantation

The purpose of this study is to evaluate the rate of perioperative bleeding complications following anticoagulation therapy in patients undergoing implantable electronic device implantation.

Utility of virtual unipolar electrogram morphologies to detect transverse conduction block and turnaround points of typical atrial flutter

BackgroundNoncontact mapping is useful for the diagnosis of various arrhythmias. Virtual unipolar electrogram morphologies (VUEM) of the conduction block and the turnaround points, however, are not well defined. We compared the VUEM characteristics of a transverse conduction block in the posterior right atrium (RA) with those of contact bipolar electrograms obtained during typical atrial flutter (AFL).MethodsContact bipolar electrograms were used to map the posterior RA during typical AFL in 16 patients. Twenty points of the VUEM recorded along the block line were analyzed and compared with contact bipolar electrograms.ResultsSeventeen AFLs were analyzed. Fifteen AFLs showed an incomplete transverse conduction block in the posterior RA by contact bipolar mapping. A double potential on the block line corresponded to the two components of the VUEM, in which the second component showed an Rs, RS, or rS pattern. At the turnaround point, a fused double potential of the contact bipolar electrograms corresponded to a change of the second component of the VUEM from an rS to a QS morphology. Two AFLs showed a complete block line in the posterior RA. The contact bipolar electrogram showed double potentials from the inferior vena cava to the superior vena cava, whereas the second component of the VUEM remained in an unchanged Rs, RS, or rS pattern.ConclusionVUEM analysis was a reliable method for identifying the posterior block line during AFL. This method may also be applicable for detecting block lines and turnaround points of circuits in other unmappable arrhythmias.

Impact of ganglionated plexi ablation on high-frequency stimulation-induced changes in atrial fibrillation cycle length in the pulmonary vein

We assessed high‐frequency stimulation (HFS)‐induced changes in the atrial fibrillation (AF) cycle length (AFCL) in the pulmonary vein (PV) after ganglionated plexi (GP) ablation.

Usefulness of MDCT Guided Mitral Isthmus Ablation

Mitral isthmus (MI) ablation is challenging. Blood flow in the CS and circumflex artery (LCx) may act as a heat sink and reduce the efficacy of radiofrequency ablation. Ablation in the CS also has the risk of injury to the LCx. We have reported to be able to visualize the precise anatomical characteristics between CS and LCx on MI obtained by MDCT. The aim of this study was to evaluate usefulness of MDCT guided MI ablation. Methods: Twenty patients (14 males, 61±11 y) whose CS and LCx images could be obtained simultaneously by MDCT were included in this study. We performed MI ablation between LIPV and the mitral annulus. The strategy for MDCT guided MI ablation were 1. MI line was designed just below LAA, 2. In case of LCx below CS, MI line was designed proximal the crossing point of LCX and CS, and 3. If LCX is presence on MI, MI line designed more laterally on comparatively peripheral LCX. Irrigated-tip catheters were used during MI ablation with the following settings: endocardial surface (maximum power: 40 W); CS (maximum power: 20 W). Results: The MI was blocked in 94.5% (19/20) of patients with 594±293 seconds of radiofrequency application. The epicardial ablation inside the CS was required in 45% (9/20) patients. No complications occurred. Conclusion: The MDCT guided MI ablation resulted in a high success rate of MI block without complications.