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NOGAMI A et al.(5) View the monitor during imaging During imaging, the heart rate must be continuously monitored using a pulse oximeter or an ECG monitor. (6) Prepare for unexpected situations It should be ensured that the room is equipped with an electrical defibrillator to be used in an emergency, if necessary. A hospital manual for handling unexpected situations should be established. In addition, it should be kept in mind that the threshold and lead resistance need to be re-measured after imaging and the mode needs to be returned to the original setting.Recommendations are shown in Table 6. Electrophysiology StudiesThe clinical significance of induced arrhythmia depends on the underlying heart disease, type of arrhythmia, and induction protocol. Electrophysiology studies are considered less useful in patients with frequent premature ventricular contraction (PVCs) without structural heart disease.

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Despite widespread use of implantable cardioverter defibrillators (ICDs), their cost and the fact that only a certain group of patients fully benefits from the devices require appropriate risk stratification of patients. This study investigated whether altered cardiac autonomic function is associated with the occurrence of ICD discharge or lethal cardiac events. Methods: Fifty-four ICD-treated patients were prospectively followed after assessment of cardiac metaiodobenzylguanidine (MIBG) activity, quantified as the heartto-mediastinum ratio (HMR), plasma concentration of brain natriuretic peptide (BNP), and left ventricular ejection fraction (LVEF). Patients were divided into 2 groups based on the presence (group A, n 5 21) or absence (group B, n 5 33) of appropriate ICD discharge during a 15-mo period. Results: Group A had a significantly lower level of MIBG activity and a higher plasma BNP level than did group B. Univariate analysis revealed BNP level, any medication, and late HMR to be significant predictors, and multivariate analysis showed late HMR to be an independent predictor. An HMR of less than 1.95 with a plasma BNP level of more than 187 pg/mL or an LVEF of less than 50% had significantly increased power to predict ICD shock: positive predictive values, 82% (HMR 1 BNP) and 58% (HMR 1 LVEF); negative predictive values, 73% (HMR 1 BNP) and 77% (HMR 1 LVEF); sensitivities, 45% (HMR 1 BNP) and 67% (HMR 1 LVEF); and specificities, 94% (HMR 1 BNP) and 70% (HMR 1 LVEF). Conclusion: When combined with plasma BNP concentration or cardiac function, cardiac MIBG activity is closely related to lethal cardiac events and can be used to identify patients who would benefit most from an ICD.

Objective-To examine the modality and morbidity of asymptomatic ST segment elevation in leads V1 to V3 with right bundle branch block (Brugada-type ST shift). Methods-8612 Japanese subjects (5987 men and 2625 women, mean age 49.2 years) who underwent a health check up in 1997 were investigated. Those with Brugada-type ST shift underwent the following further examinations over a two year period after the initial check up: ECG, echocardiogram, 24 hour Holter monitoring, treadmill exercise testing, signal averaged ECG, and slow kinetic sodium channel blocker loading test (cibenzoline, 1.4 mg/kg). Results-Asymptomatic Brugada-type ST shift was found in 12 of 8612 (0.14%) subjects. Eleven of these 12 subjects were followed up. Follow up ECG exhibited persistent Brugada-type ST shift in seven of 11 (63.6%) subjects. ST shift was transformed from a saddle back to a coved type in three subjects. None of the subjects had morphological abnormalities or abnormal tachyarrhythmias. Positive late potentials were found in seven of 11 (63.6%) subjects. Augmentation of ST shift was shown by both submaximal exercise and drug administration in one of the 11 subjects (9.1%). Conclusions-Asymptomatic subjects with Brugada-type ST shift were not unusual, at a rate of 0.14% in the general Japanese population. Almost all of the subjects had some abnormalities in non-invasive secondary examinations. Additional and prospective studies are needed to confirm the clinical significance and the prognosis of asymptomatic Brugada-type ST shift. (Heart 2001;86:161-166) Keywords: Brugada syndrome; signal averaged electrocardiogram; sodium channel blocker; sudden death Since Brugada and Brugada 1 first described eight cases of characteristic ECG features consisting of right bundle branch block (RBBB) and persistent ST segment elevation in leads V1 to V3 (Brugada-type ST shift) associated with aborted cardiac sudden death without structural heart diseases, clinical evidence of a link between Brugada-type ST shift and cardiac sudden death has been accumulating. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Because of increasing awareness of this evidence, a Brugada-type ST shift is being discovered incidentally in more and more asymptomatic subjects. Some recent reports describe Brugada-type ST shift recognised in asymptomatic subjects.5 15 However, the clinical significance of Brugada-type ST shift in asymptomatic subjects is unclear. Therefore, it is still not known whether a Brugada-type ST shift is a specific indicator of ventricular fibrillation or a life threatening sign of sudden cardiac death.On the basis of these speculations, we investigated the prevalence of asymptomatic Brugada-type ST shift in the general Japanese population and performed secondary cardiovascular examinations focusing on latent myocardial involvement in the screened subjects. Methods STUDY POPULATIONThe study population consisted of 8612 adult Japanese subjects (5987 men and 2625 women) ranging in age from 22-84 years (mean 49.2 years). All...