Since the first report of catheter ablation curing atrial fibrillation (AF), numerous techniques have evolved, from linear ablation to segmental pulmonary vein (PV) isolation, extensive encircling PV isolation, LA linear ablation, ablation of complex fragmented atrial electrograms (CFAE) and stepwise ablation. We developed a new approach for complete isolation of the posterior LA including all PVs, namely box isolation. In the posterior LA, there are many arrhythmogenic substrates for AF, including the triggers, reentries and ganglionated plexi. Box isolation can contain these abnormal substrates in the posterior LA. Box isolation is associated with a high clinical success rate in paroxysmal AF. However, in persistent AF or longstanding persistent AF, only box isolation may not be sufficient, therefore, additional ablation at sites with CFAE outside the box area is needed to improve the clinical outcome. A hybrid approach of combining box isolation with CFAE ablation is highly effective in the majority of patients with persistent AF or longstanding persistent AF. Thus, AF ablation is an effective and safe treatment for AF that offers an excellent chance for a lasting cure.

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Catheter ablation of atrial fibrillation (AF) has been making remarkable progress for the last decade. When manipulating the catheter in the procedure, we have to reconstruct the three-dimensional cardiac structure in our heads by using two-dimensional fluoroscopic image. The author, an interventional electrophysiologist, developed and proposed a new method for recognizing the cardiac structure by using human body sections.
In order to easily create practical cardiac images, the human bodies were cut sagittally, obliquely and coronally. In the sections obtained, the heart could be observed together with their surroundings within the thorax in the neutral position. The most important point is that the heart is observed without being removed from the body. This concept of the research is to recognize the heart as an object composed of many structures. It was useful for analyzing the mechanism of arrhythmia and to improve catheter technique and mapping systems.

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Postural orthostatic tachycardia syndrome (POTS) is defined as the development of orthostatic symptoms associated with a rapid (within 10 minutes) increase in heart rate by more than 30 beats per minute or to a heart rate that exceeds 120 beats per minute without orthostatic hypotension. The symptoms of orthostatic intolerance are due to brain hypoperfusion and sympathetic overaction. Patients are usually female and aged 15 to 50 years. POTS represents a category of disease rather than a single distinct illness. Patients with POTS can experience difficulty with daily routines including housework, shopping, eating, and attending work or school. Reports of patients with “POTS-like symptoms” have been made for over 100 years.
The pathophysiologic mechanisms of POTS include peripheral denervation, β-receptor supersensitivity, hypovolemia and impaired cerebral autoregulation. Prolonged deconditioning may also interact with these mechanisms to exacerbate symptoms. Although 3 types of POTS (low-flow, normal-flow, and high-flow POTS) have been distinguished based on differences in peripheral blood flow and peripheral arterial resistance, thoracic hypovolemia is the common final pathophysiologic mechanism.
Therapies are directed at relieving the central hypovolemia or at compensating for the circulatory dysfunctions. Treatments include use of water, saline infusion, α-agonists, β-antagonists, and other agents that may correct the central hypovolemia. These have resulted in varying degrees of success, and they are often used in combination.

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Background: Automaticity of cardiac devices is designed to reduce the burden on physicians while securing patient safety. The aim of this study is to elucidate accuracy of automatic adjustment algorithm of pacing output and effectiveness of this feature for time reduction during clinic visits.
Methods and Results: Patients implanted with pacemakers capable of automatically adjusting the pacing output were enrolled. During their routine device follow-ups, pacing thresholds were compared between manual measurements and most recently recorded data in the device, which had been measured automatically at prespecified timing. Difference between −0.25 and 0.5 volts were predefined as equivalent. Time required for conventional follow-up was also compared to device interrogation and data assessment. A total of 359 patients from 32 centers were enrolled. Calculated 95% confidence interval of difference in volts for atrium was (−0.0625,0) and the difference for ventricle was nonsignificant. These results met the equivalence criteria. Observed time to interrogate and assess device-stored pacing threshold was shorter by average of 3.3 minutes compared to manual method.
Conclusions: The pacing threshold determined by the automatic measurement algorithm was accurate. Follow-up time was shorter when utilizing automaticity of pacemakers. The system is safe and time efficient.

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Background: Ablation of complex fractionated atrial electrograms (CFAE) is now performed in patients with persistent atrial fibrillation (AF). However, extensive ablation is often necessary to eliminate all CFAE or to terminate AF. The purpose of this study was to evaluate the effects of antiarrhythmic drugs (AAD) on CFAE.
Methods and Results: Sixty patients, including 38 with longstanding persistent AF and 22 with persistent AF, underwent box isolation. After box isolation, CFAE maps were created before and after infusion of a pure Na⁺ blocker, pilsicainide (1 mg/kg), in 30 patients or a pure I_Kr blocker, nifekalant (0.3 mg/kg), in 30 patients. Nifekalant had a greater effect on AF termination than pilsicainide (33.3% versus 6.7%, P=0.01). Both AADs similarly reduced CFAE. Ablation of CFAE localized by nifekalant and pilsicainide terminated AF in 26.7% and 20% of the patients, respectively. After a single ablation procedure, patients in whom AF was terminated by CFAE ablation had a lower recurrence rate than those in whom AF was not terminated despite CFAE ablation (19.2% versus 35.3%, P=0.04).
Conclusions: Both pilsicainide and nifekalant reduce CFAE, and nifekalant has a greater effect on AF termination than pilsicainide. Ablation of only CFAE localized with AAD may be sufficient for clinical efficacy.uhhh

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Background: β-blockers offer the first line therapy in congenital long QT syndrome (LQTS), and are more effective to prevent the cardiac event in LQTS type 1 than in type 2 or 3. In contrast, left cardiac sympathetic denervation (LCSD) was shown to be highly effective in patients refractory to β-blockers. Total sympathetic ablation by LCSD indicates the addititional involvement of α-adrenoceptor-mediated pathway. In genotyped LQT2 patients, we therefore hypothesized that blockade of α-adrenoceptor in addition to β-adrenoceptor by carvedilol could reduce cardiac events more efficiently than other types of β-blockers.
Methods and Results: The study population consisted of 51 genotyped LQT2 patients (18 males, 23±11 years old). They were divided into 2 groups (group 1: 43 patients treated with selective β-blockers, group 2: 8 patients with carvedilol) and retrospectively analyzed the efficacy of the respective β-blocker therapy in suppressing cardiac events. Cardiac events were observed in 11 patients of group 1 (26%) but none in group 2 during a follow-up period of 83±80 months (P=0.098).
Conclusions: Carvedilol may be a potentially beneficial therapy for genotyped LQT2 patients who are refractory to other β selective blockers.

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We describe a patient with torsades de pointes (TdP) who was implanted with cardiac resynchronization therapy defibrillator (CRT-D). At the time of CRT-D implantation, left ventricular (LV) epicardial pacing exacerbated TdPs and developed into electrical storm, which was triggered even by biventricular pacing. We needed to inactivate the LV lead for 2 weeks. At the next device check testing of LV pacing still induced TdPs, whereas biventricular pacing did not. After starting the continuous biventricular pacing no ventricular arrhythmias happened, and furthermore the QT intervals prolonged by LV pacing were obviously shortened only after 2 weeks as ventricular systolic function recovered. Then even continuous LV alone pacing induced no TdP. These findings indicate novel electrical effects of cardiac resynchronization therapy.

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Reel syndrome is a variant form of twiddler’s syndrome. We describe a 53 years old woman who was referred to our hospital because of symptomatic sinus bradycardia. Subsequently she underwent dual chamber pacemaker implantation and was sent back to the previous hospital on the following day. She was referred again because of sudden syncope due to low heart rate 2 weeks following implantation. Chest X-ray revealed leads had pulled out of the heart and coiled up around the pacemaker generator; a diagnosis of reel syndrome was made. The difference between the two syndromes, risk factors and preventive measures were discussed.

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Implantation of a transvenous endocardial pacing lead in the right ventricle is contraindicated after mechanical tricuspid valve replacement; therefore a surgical approach to the epicardium is usually required. This case report describes ventricular pacing via a branch of the coronary sinus in a patient with mechanical mitral, aortic and tricuspid valve replacements. In conclusion, this approach is minimally invasive, provides effective ventricular stimulation with low pacing threshold and stable lead position, and is a feasible option when transvenous right ventricular pacing is not possible.

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