Ischemic heart disease (IHD) is one of the leading causes of death in the general population. Ischemia induces changes in the electrophysiologic properties of the myocardium that sometimes cannot be detected with rest ECG, which has a relatively low sensitivity. Magnetocardiography (MCG) which records the magnetic fields generated by the heart, is reported more sensitive for measuring myocardial electric activity. Many analyzing methods using MCG for the diagnosis of IHD are reported. Those methods can be summarized as follows:
1. magnetic measurement of ST and TQ segment shift,
2. spatial dispersion of the magnetocardiographically determined QT intervals (QT dispersion),
3. ST current angle rotation of magnetic field (isomagnetic map) at rest or in exercise magnetocardiography,
4. analyzing current arrow map during ventricular repolarization, and
5. analyzing the integral values of reporalization
In this review we will given an overview of the current status of MCG methods for the diagnosis of IHD.

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There are few long-term reports of patients with frequent PVCs in the absence of ischemic heart disease. In 86 patients without ischemic heart disease, who had 1000 or more PVCs in 24-hour Holter ECG, the number of PVCs during 24-hours Holter ECG and echocardiographic parameters were followed at least 1 year (66.5±39.7 months). PVC was significantly reduced in the patients with or without underlying diseases (UD). The reduction rate in the number of PVCs was prominent in patients with UD. PVC was significantly reduced in patients under medication, but not in patients without medication. In the comparison between the initial and follow up observation using Wilcoxon’s rank test, the number of PVC was significantly reduced (P<0.05), and EF was also improved (P<0.05) in angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) group, and in β-blocker group. In Ca-antagonist group and antiarrhythmic drug group, the number of PVCs was also significantly reduced (P<0.05). Multivariate analysis revealed significantly higher incidence (60% or more with PVC reduction) in ACEI/ARB group.
These results suggest that the administration of ACEI/ARB may contribute to the reduction of PVC in non-ischemic heart disease cases with multiple PVC.

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Introduction: Unlike cardiac arrest occurring out-of-hospital, the safety and efficacy of automated external defibrillators (AED) in the hospital has not been assessed. This study examined the conditions of AED use in hospital and the prognosis of these patients.
Methods and Results: We examined the condition and prognosis of 32 patients who were given AED treatment while they were in an unconscious state in the hospital, between May 2004 and January 2007. During this period, AED was used only for patients, not for visitors or hospital personnel.
Ventricular fibrillation (VF) or ventricular tachycardia (VT) was observed in 7 patients, and in the other 25 the initial rhythm of the patients did not require AED. Two patients survived with the help of AED, but it did not deliver shock in two patients with VF and VT. There was no significant difference in vital prognosis due to the presence or absence of shock delivery in the VF or VT patients.
Conclusion: The situation of AED use may be different whether it is used in hospital or out-of-hospital. This study suggests that using AED in the hospital may have limited effect when it is used for critically ill patients.

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Focal atrial tachycardia (AT) is sometimes associated with sick sinus syndrome. A 57-year-old female complained of palpitation, fatigue and presyncope. Ambulatory monitoring demonstrated frequent segments of AT and subsequent sinus arrests. P wave morphology of ectopic beats was similar to that of sinus rhythm. After obtaining diagnosis of bradycardia tachycardia syndrome, she underwent electrophysiologic study (EPS) and radiofrequency (RF) catheter ablation to eliminate AT.
Conventional EPS could not be performed due to frequent spontaneous ectopic beats. EnSite mapping demonstrated that AT originates from posterosuperior right atrium (RA) and that local electrogram of ectopic focus precedes the onset of P wave in surface ECG by 40 msec. After EnSite-guided RF ablation to the target area, ambulatory monitoring detected no AT or sinus arrest. EPS performed one week after RF ablation showed atropine-induced partial restoration of sinus node dysfunction.
Her symptoms were resolved remarkably and permanent pacemaker implantation has not been necessary to date. RF ablation guided by EnSite mapping was useful to eliminate AT arising from limited ectopic focus and this case implies existence of “pacemaker-avoidable” bradycardia tachycardia syndrome.

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A 74-year-old man presented with palpitation and 12-lead ECG exhibited atrial premature contraction (APC) at general check-up. Holter ECG demonstrated narrow QRS tachycardia with a rate of 160/min and more than 31,000/day atrial premature beats. The P wave morphology of atrial premature beats showed negative in II, III, aVF and biphasic in V1. Venography was performed and disclosed persistent left superior vena cava (LSVC) draining into the right atrium via the markedly dilated coronary sinus (CS). Electrogram recordings from LSVC and CS were obtained with an electrode catheter via the left subclavian vein. At the level where a ventricular potential disappeared, the intra-LSVC potentials began to show a discrete second sharp potential after local left atrial signals. Double potentials were obtained within the LSVC from the lower left atrium (LA) to the higher LA. A proximal-to-distal activation sequence of the second components was observed. The interval between the 1st and 2nd component ranged from 8 to 22 msec between the proximal LSVC and distal LSVC. The double potentials resulted in fusion at the lower part of the LSVC, indicating the presence of an electrical connection between the LSVC and lower LA.

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Here we present a 15-year old female in whom an idiopathic ventricular tachycardia (VT) originating from the left aortic sinus cusp was eliminated by radiofrequency catheter ablation (RFCA) under navigation using a noncontact mapping system (NCM). The dynamic activation map constructed with the NCM clearly identified a VT focus in the left aortic sinus cusp, from which the activation spread out to the entire left ventricle. At that site, the virtual unipolar electrogram recorded with the NCM was the same as the contact unipolar electrogram in terms of morphology and timing, a pre-systolic potential preceding the QRS complex by 40 msec was recorded by contact bipolar electrogram and rapid pacing during sinus rhythm resulted in a perfect pace match. RFCA at that site eliminated the VT and the patient has had no recurrence during 10 months of follow-up.

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