Inherited arrhythmia syndromes account for approximately 10% as a cause of sudden cardiac death (SCD) in Asian countries, which include congenital long QT syndrome (LQTS), Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, short QT syndrome, and early repolarization syndrome. Since SCD in inherited arrhythmia syndromes develop generally in young to middle age, it is of particular importance in health policy to reveal its pathophysiology and to prevent SCD. Over the past two decades, molecular genetic studies have established a link between a number of inherited arrhythmia syndromes and mutations in genes encoding for ion channels or other membrane components. In some inherited arrhythmia syndromes such as congenital LQTS, genotype-phenotype correlation has been fully investigated, and attributable to risk stratification as well as genotype-specific therapy in individuals. Recent advances of molecular genetics includes genome-wide association study (GWAS) using gene array and whole exome and whole genome study using next generation sequencer, which are promising tools for identifying new candidate gene responsible for inherited arrhythmia syndromes. In this symposium, expert physicians and researchers are welcome to present their own experience and provide a comprehensive discussion for the growing cutting-edge of SCD due to inherited arrhythmia syndromes.

Pulmonary vein isolation is the cornerstone technique of atrial fibrillation (AF) ablation, particularly for paroxysmal AF. On the other hand, in patients with persistent AF, the success rate of pulmonary vein isolation alone is substantially low. To improve the outcome of ablation in persistent AF, several additional ablation strategies, such as linear ablation or complex fractionated atrial electrogram (CFAE) ablation have been explored. The STAR AF-II trial indicated that additional CFAE or linear ablation following pulmonary vein isolation increases the procedural time and does not improve the ablation outcomes in patients with persistent AF. However, patients with persistent AF lasting less than 1 year were included in this trial. Recently, specific substrate modification strategies targeting rotors or low-voltage areas for persistent AF have produced encouraging early results but need to be verified in further studies. Therefore, ablation of long-standing persistent AF is still challenging.
In this symposium, we discuss the efficacy and limitations of different ablation strategies for long-standing persistent AF.

Ventricular tachycardia (VT) and ventricular fibrillation (VF) either with or without underlying heart disease has been demonstrated to be treatment refractory and demonstrated to have poor prognosis.

The implantable cardioverter-defibrillator (ICD) became to be the standard therapy to prevent sudden cardiac death in those patients; however, those malignant ventricular tachy-arrhythmias has been shown to have still poor prognosis when frequent shocks of ICD were observed.

Several studies have been shown that the ablation of the arrhythmogenic substrate of VT/VF could reduce or prevent the recurrence of ventricular tachycardia/ventricular fibrillation in those patients; however, there are many hidden truth to be elucidated.

More recently, stellate ganglion block, which pain physician and/or anesthesiologists routinely perform for the treatment of painful upper extremity sympathetic dystrophy, has been successfully used to the patients with refractory and intractable ventricular tachy-arrhythmias.

Major reasons to have difficulties to treat are that truth of both the basic and the clinical background of the malignant refractory ventricular tachy-arrhythmia remains unknown. The reasons to be clarified are those the lack of true knowledge of the underlying mechanism of VT/VF, the lack of true understanding of 3D arrhythmogenic substrate to maintain VT/VF, the lack of real evaluation of the ablation sizes, and the lack of the true evaluation of the influences of the autonomic tone, etc.

In this symposium, we are delighted to have mostly updated researches to address those questions adequately from both the clinical and the basic fields.

Ionizing radiation exposure has deterministic effects (e.g., skin injuries, cataracts, etc.) and a long-term cancer risk. Therefore, all physicians have the responsibility to balance the radiation exposure versus the diagnostic and therapeutic gain of the imaging (‘justification’), and to minimize the hazard of a radiation risk to their patients, other staff members, and themselves (‘optimization’). Cardiac electrophysiologists have an exposure per annum two to three times higher than that of diagnostic radiologists. The radiation doses can range from an equivalent of 1–60 milliSievert (mSv) around a reference dose average of 15 mSv (corresponding to 750 chest X-rays) for a cardiac radiofrequency ablation procedure. The reference dose for a regular pacemaker or implantable cardioverter defibrillator implantation is 4 mSv (range 1.4-17) and 22 mSv (range 2.2-95) for a cardiac resynchronization therapy implantation. Doses on the order of a magnitude of 10-100 mSv correspond to a low (albeit definite, not negligible) additional lifetime risk of fatal and non-fatal cancer from between 1 in 1000 (10 mSv) to 1 in 100 (100 mSv). The system and workflow adaptations, use of shielding measures, and use of advanced, non-fluoroscopic imaging techniques can reduce the radiation exposure.
This symposium focuses on methods and techniques to ‘optimize protection’ for patients and operators during non-pharmacotherapy of cardiac arrhythmias. We hope that this symposium will help all the electrophysiologists to reduce the radiation exposure by more than an order of magnitude.

Numerous progresses have been made in anticoagulation therapy to prevent strokes in recent years and greatly improved our clinical practice particularly in patients with atrial fibrillation (AF). These included (1) AF patient stratification with risk scores, (2) development of innovative tools of direct oral anticoagulants (DOACs), and (3) large-scale clinical trials with warfarin and DOACs. More recently, “real world data” has been rapidly accumulated to extrapolate the efficacy under clinical trials to the effectiveness under real world. The information has much contributed to the wide and rapid prevail of effective anticoagulation therapy for AF patients, hopefully leading to decrease in embolic strokes. On the contrary, physicians are apparently annoyed by this deluge of information. Actually, some of them might be misleading or disappointing and thus cannot be extrapolated to our clinical practice, because of differences in races, patient backgrounds and medical environments. In this symposium, we discuss the gaps between medical information and everyday real clinical practice for stroke prevention in AF patients.

Sudden cardiac death (SCD) is a major concern in the public health scene even after the wide-spread use of ICD therapy for the prevention of SCD due to fatal ventricular arrhythmias (VA).
To assess the risk of SCD, left ventricular ejection fraction (EF) is known to be the only powerful predictor of SCD in patients with ischemic or non-ischemic cardiomyopathy. Although other methods of assessing electrical activity of the heart or autonomic nervous activity are used for predicting fatal VA or SCD, most of these examinations have insufficient clinical evidence for the prevention of SCD. More reliable risk stratification beyond EF would be expected. In addition, individual risk assessment is also required for other causes of SCD like hereditary fatal VA syndrome.
The trans-venous ICD therapy is currently established as the main tool for primary and secondary prevention of SCD. Recently, subcutaneous ICD has become available in Japan and the clinical efficacy has also been reported. Needless to say, the efficacy of ICD for preventing SCD is obvious;however, serious mechanical and functional complications or infection problems still remain. In addition, the indication gap for primary prevention between the guidelines and real clinical practice is often observed. Various factors may be related to this gap, but it often causes the underuse of ICD even in appropriately indicated patients.
In this session, we would like to discuss a comprehensive approach for preventing SCD from the risk assessment to the efficacy and limitation of ICD therapy.

CRT has been growing as new non-pharmacological therapy in patients with drug refractory heart failure in the world wide, especially in NYHA Class II-IV patients. Presence of wider QRS duration >150msec. and CLBBB, or absence of AF believed to respond well to CRT. In fact that Class I indications in most countries clinical guidelines include these factors in patients with heart failure. Nevertheless, approximately 30-40% of the CRT patients have been reported as non-responder in real world.

In this symposium, we discuss the following clinical important issues;

• How should we select the CRT patients and what is the most important factor for prediction of responder before CRT?
• When and how should we assess the patients as responder or non-responder after CRT?
• Where should we select pacing area at the implantation in both RV and LV sites?
• How should we manage in non-responder CRT patients?
• How should we reset the pacing parameters in non-responder CRT patients?

These issues seem to be very important clinical issues in the current CRT management for clinician. We are very welcome to submit your research or clinical data for management of CRT in this symposium.

Several large randomized trials have demonstrated the important role of the implantable cardioverter-defibrillator (ICD) for the improvement in mortality in patients with a high risk of sudden cardiac death, regardless of its purpose (primary or secondary prevention) and of underlying heart disease (ischemic or non-ischemic).
MADIT-RIT demonstrated that strict ICD programming to a high-rate (>200 bpm) or long (60sec) duration-delay is associated with a 75% reduction in a 1st inappropriate therapy, and 50% reduction in all-cause mortality in patients for primary prevention. The results from this trial were exciting. However, the fact that a reduction in the inappropriate shocks can be achieved by rigorous programming to this extent represents an immature discrimination capability of the device itself. The establishment of a further advanced algorithm with both a high sensitivity and specificity is required.
Subcutaneous ICDs (S-ICDs) are revolutionary devices to prevent sudden cardiac death without any requirement of venous access. The inability of bradycardia or anti-tachycardia pacing and a relatively high incidence of inappropriate therapies are unresolved problems.
The efficacy of ICDs in patients with newly diagnosed heart failure is limited. To avoid any sudden cardiac death during an appropriate interval to decide the indication of an ICD, a wearable cardioverter-defibrillator (WCD) should be challenged. Through the experience of a wider usage of WCDs, the role of drug therapy for heart failure or acute coronary intervention to prevent sudden cardiac death can be re-evaluated.
In this symposium, the advanced role of several shock-devices, at the present time and in near future, will be discussed.

Now, remote monitoring of cardiovascular implantable electronic devices (CIEDs) are widely used. Remote monitoring of devices are useful for emergency. It is reported that prognosis of CEIDs patients are improved by remote monitoring of devices. However, burden of the medical staff may be increased. On the other hand, routine hospital visits of the CIEDs patients may be decreased by remote monitoring. Burden of the medical staff can be decreased by appropriate use of monitoring system. Operation of remote monitoring system can be achieved not only by physicians but also other staffs including nurse and medical engineer. Building suppo rt system of remote monitoring in each hospital may be key issue. Important thing is to clarify purposes of remote monitoring system. And we want to know how to use remote monitoring system. We want to discuss about these issues in this symposium and hope many submissions and contribution for this symposium.