Masateru Kondo

Delayed enhancement on cardiac magnetic resonance imaging is a poor prognostic factor in patients with cardiac sarcoidosis

BACKGROUND Predictors of ventricular arrhythmias (VA) in patients with cardiac sarcoidosis (CS) remain unclear. METHODS AND RESULTS We examined 61 consecutive CS patients who were admitted to our hospital from April 2002 to March 2012 with a mean follow-up period of 45 ± 31 months for the relationship between delayed enhancement on cardiac magnetic resonance imaging (DE-MRI) and VA or a composite endpoint, including VA, heart failure hospitalization, and cardiovascular mortality. Although there was no significant difference in baseline clinical characteristics between patients with VA and those without it, the former group was characterized as compared with the latter by lower left ventricular (LV) ejection fraction (p<0.05), larger LV systolic/diastolic dimensions (both p<0.05), and a significant association with DE-MRI (p<0.05). Furthermore, the patients with DE-MRI (n=26), as compared with those without it (n=11), had a significantly higher composite endpoint event rate (41% vs. 0%, p<0.05) and a trend toward higher VA (29% vs. 0%, p=0.12). Univariate analysis also showed that impaired LV systolic function was significantly associated with composite events on follow-up. CONCLUSIONS These results indicate that the presence of DE-MRI is a significant predictor of VA events and poor outcome in CS patients.

Current Status of Primary Prevention of Sudden Cardiac Death With Implantable Cardioverter Defibrillator in Patients With Chronic Heart Failure

BACKGROUND The current status of primary prevention of sudden cardiac death (SCD) with implantable cardioverter defibrillator (ICD) in patients with heart failure with reduced ejection fraction remains to be fully elucidated in Japan. METHODS AND RESULTS In the chronic heart failure (CHF) cohort study, the CHART-2 Study, we enrolled 2,778 consecutive patients with NYHA class II-III. According to the Japanese Circulation Society guideline of prophylactic ICD, we divided them into 3 groups: group A, class I indication; B, class IIa; and C, no indication. During the (median) 3.2-year follow-up, 79 fatal arrhythmic events (FAE), defined as composite of sudden cardiac/arrhythmic death, ventricular tachycardia/fibrillation and appropriate ICD therapy, occurred. In the groups A, B and C, the prevalence of FAE was 16.1%, 8.9% and 1.9%, respectively; the use of prophylactic ICD among those with FAE, however, was only 44%, 9% and 6%, respectively. In the groups A and B combined, chronic atrial fibrillation (cAF) and left ventricular end-diastolic dimension (LVDd) ≥ 65 mm were independent predictors of FAE, and, when combined, their prognostic impact was highly significant (hazard ratio, 7.01; P<0.001). CONCLUSIONS Primary prevention of SCD with ICD in CHF patients is validated but is still underused in Japan, and the combination of cAF and LVDd ≥ 65 mm may be a useful indication of prophylactic ICD implantation.

Time Course and Factors Correlating With Ventricular Tachyarrhythmias After Introduction of Steroid Therapy in Cardiac Sarcoidosis

Background—The time course and factors correlating with ventricular tachyarrhythmias (VTs) after introduction of corticosteroid therapy in patients with cardiac sarcoidosis remain to be elucidated. Methods and Results—We examined 68 consecutive patients with cardiac sarcoidosis in the Tohoku University Hospital from October 1998 to September 2014 (age: 57±11 years old; male:female 18:50) and evaluated VTs after initiation of steroid therapy. VTs were defined as documented ventricular tachycardia or ventricular fibrillation lasting for more than 30 seconds or resulting in cardiovascular collapse, or appropriate implantable cardioverter defibrillator therapy. During a mean follow-up of 5.5 years, 20 out of 68 patients (29%) experienced VTs after initiation of corticosteroid therapy, especially in the first 12 months in 14 patients (70%). A multivariable analysis revealed that positive gallium scintigraphy had a significant correlation with VTs (hazard ratio, 11.33; 95% confidence interval, 3.22–39.92; P<0.001), in addition to reduced left ventricular ejection fraction (hazard ratio, 0.94; 95% confidence interval, 0.90–0.97; P=0.001). Furthermore, electrical storm was noted in 10 patients (14.7%), 8 within the first 12 months of treatment, whereas the recurrence of electric storm was relatively less. Conclusions—These results indicate that VTs and electric storm frequently occur in the first 12 months after initiation of corticosteroid therapy, presumably because of inflammatory conditions, and that the positive gallium scintigraphy is a significant and independent predictor of VTs. The present findings may be useful to further improve the management of VTs in patients with cardiac sarcoidosis.

Development of a Novel Shock Wave Catheter Ablation System -The First Feasibility Study in Pigs-

Introduction Radio-frequency catheter ablation (RFCA) using Joule heat has two fundamental weaknesses: the limited depth of treatment and the risk of thrombus formation. In contrast, focused shock wave (SW) therapy could damage tissues at arbitrary depths without heat generation. Thus, we aimed to develop a SW catheter ablation (SWCA) system that could compensate for the weaknesses of RFCA therapy. Methods and Results We developed a SWCA system where the SW generated by a Q-switched Holmium: yttrium aluminum garnet (YAG) laser beam was reflected by a reflector attached to 14-Fr catheter tip and then was converged onto the focus. We examined the feasibility of our system on pigs in vivo. When applied using the epicardial approach, the SWCA caused persistent spheroidal lesions with mild superficial injury than the RFCA. The lesions were created to a depth based on the focal length (2.0 mm) [2.36 ± 0.45 (SD) mm immediately after procedure, n = 16]. When applied to the atrioventricular (AV) node using the endocardial approach, the SWCA caused junctional escape rhythms in 2 pigs and AV block in 12 pigs (complete AV block in 9) in acute phase (n = 14). Nine of the 14 pigs survived with pacemakers for the long-term study, and the AV block persisted for 12.6 ± 3.9 (SD) days in all surviving pigs. Histological examination showed AV nodal cell body atrophy in the acute phase and fibrotic lesions in the chronic phase. Importantly, no acute or chronic fatal complications were noted. Conclusions Our novel SWCA system could be a promising modality as a non-thermal ablation method to compensate for the weaknesses of RFCA therapy. However, further research and development will be necessary as the current prototype still exhibited the presence of micro-thrombus formation in the animal studies.

Comparison of the measured pre-ejection periods and left ventricular ejection times between echocardiography and impedance cardiography for optimizing cardiac resynchronization therapy

The pre‐ejection period (PEP) and left ventricular ejection time (LVET) are easily measured by impedance cardiography (ICG). We hypothesized that the PEP/LVET measured by ICG would correlate with that measured by echocardiography, and that PEP/LVET measured by ICG would be useful for cardiac resynchronization therapy (CRT) optimization.

Usefulness of Testing for Coronary Artery Spasm and Programmed Ventricular Stimulation in Survivors of Out-of-Hospital Cardiac Arrest

Background—Optimal therapy for patients resuscitated from out-of-hospital cardiac arrest (OHCA) who are not found to have structural heart disease remains to be established, especially regarding the use of implantable cardioverter-defibrillators. Coronary artery spasm (CAS) and lethal ventricular arrhythmias are important causes of OHCA. Methods and Results—In 47 consecutive OHCA survivors without structural heart disease who had fully recovered (M/F 44/3, 43±13 years.), we performed dual induction tests, including acetylcholine provocation test first followed by programmed ventricular stimulation after 1 to 2 weeks. Patients with CAS were treated with calcium channel blocker–based antianginal medications; implantable cardioverter-defibrillators were implanted in all patients. The results of the dual induction tests defined 4 groups: CAS alone (n=7), inducible ventricular arrhythmias alone (n=13), both positive (n=24), and both negative (n=3). During a median follow-up period of 38 months, ventricular fibrillation recurred in all groups except the both-negative group. Of the 16 patients with a type I Brugada ECG, 2 had CAS alone, 8 had ventricular arrhythmias alone, and 6 had both positive. No ventricular fibrillation episodes were observed in the CAS-alone patients who did not also have Brugada syndrome. Kaplan–Meier analysis showed that the CAS-alone group was at lower risk for OHCA recurrence as compared with the Brugada syndrome group (log-rank test; P=0.036). Conclusions—Among OHCA survivors without structural heart disease, provokable CAS and ventricular arrhythmias are common and can be seen in Brugada syndrome. CAS alone without Brugada syndrome who are treated for CAS may be a lower-risk group.

Usefulness of the Noncontact Mapping System to Elucidate the Conduction Property for the Treatment of Common Atrial Flutter

Background: The functional role of the cavotricuspid isthmus (CTI) for common atrial flutter (cAFL) remains to be elucidated. In the present study, we examined whether the EnSite system (St. Jude Medical, St. Paul, MN, USA), a noncontact mapping system, is useful to evaluate the conduction properties of CTI to minimize radiofrequency (RF) ablation applications for cAFL.

Stressful medical explanation may cause syncope in patients with emotion-triggered neurocardiogenic syncope

1Department ofNeurology, TohokuUniversityGraduate School ofMedicine, Sendai, Japan 2Department of Epileptology, TohokuUniversityGraduate School ofMedicine, Sendai, Japan 3Department of CardiovascularMedicine, TohokuUniversityGraduate School ofMedicine, Sendai, Japan Correspondence YosukeKakisaka,DepartmentofEpileptology, TohokuUniversityGraduateSchool ofMedicine, 2-1Seiryo-machi, Aoba-ku, Sendai,Miyagi 980–8575, Japan. Email: kakisuke@mui.biglobe.ne.jp

Sudden failure of ventricular pacing and recovery in a patient with cardiac sarcoidosis

A 76‐year‐old woman with sarcoidosis who had an implantable pacemaker for complete atrioventricular block was admitted with syncope. Electrocardiogram revealed ventricular pacing failure, and a marked rise in the ventricular pacing threshold. 18F‐Fluorodeoxyglucose positron emission tomography (FDG‐PET) indicated increased uptake of FDG in the ventricular septum. Three days after steroid therapy, the ventricular pacing threshold reverted to normal, and FDG‐PET showed decreased FDG uptake in the ventricular septum. In this case report, we demonstrate that a sudden deterioration in the ventricular pacing threshold due to worsening cardiac sarcoidosis can be reversed with early steroid therapy.

Development of a Novel Shock Wave Catheter Ablation System

Although radio-frequency catheter ablation (RFCA) is quite effective for the treatment tachyarrhythmias, it possesses two fundamental limitations, including limited efficacy for the treatment of ventricular tachyarrhythmias of epicardial origin and the risk of thromboembolism. Consequently, new method is required, which can eradicate arrhythmia source in deep part of cardiac muscle without heating. On the other hand, for a medical application of shock waves, extracorporeal shock wave lithotripter (ESWL) has been established [1]. It was demonstrated that the underwater shock focusing is one of most efficient method to generate a controlled high pressure in a small region [2]. In order to overcome limitations of existing methods, we aimed to develop a new catheter ablation system with underwater shock waves that can treat myocardium at arbitrary depth without causing heat.