Hirotsugu Atarashi

Long-Term Prognosis of Probands With Brugada-Pattern ST-Elevation in Leads V1–V3

Background—The prognosis of patients with saddleback or noncoved type (non–type 1) ST-elevation in Brugada syndrome is unknown. The purpose of this study was to clarify the long-term prognosis of probands with non–type 1 ECG and those with coved (type 1) Brugada-pattern ECG. Methods and Results—A total of 330 (123 symptomatic, 207 asymptomatic) probands with a coved or saddleback ST-elevation ≥1 mm in leads V1–V3 were divided into 2 ECG groups—type 1 (245 probands) and non–type 1 (85 probands)—and were prospectively followed for 48.7±15.0 months. The absence of type 1 ECG was confirmed by drug provocation test and multiple recordings. The ratio of individuals with a family history of sudden cardiac death (14%) was lower than previous studies. Clinical profiles and outcomes were not notably different between the 2 groups (annual arrhythmic event rate of probands with ventricular fibrillation; type 1: 10.2%, non–type 1: 10.6%, probands with syncope; type 1: 0.6%, non–type 1: 1.2%, and asymptomatic probands; type 1: 0.5%, non–type 1: 0%). Family history of sudden cardiac death at age <45 years and coexistence of inferolateral early repolarization with Brugada-pattern ECG were independent predictors of fatal arrhythmic events (hazard ratio, 3.28; 95% confidence interval, 1.42 to 7.60; P=0.005; hazard ratio, 2.66; 95% confidence interval, 1.06 to 6.71; P=0.03, respectively, by multivariate analysis), although spontaneous type 1 ECG and ventricular fibrillation inducibility by electrophysiological study were not reliable parameters. Conclusions—The long-term prognosis of probands in non–type 1 group was similar to that of type 1 group. Family history of sudden cardiac death and the presence of early repolarization were predictors of poor outcome in this study, which included only probands with Brugada-pattern ST-elevation.

Prevalence of atrial fibrillation in the general population of Japan: An analysis based on periodic health examination

BACKGROUND The mortality and morbidity rates of various cardiovascular diseases differ between Western countries and Japan. The age- and gender-specific prevalence rate of atrial fibrillation (AF) in the general population of Japan was determined using the data from periodic health examinations in 2003. METHODS Data of 630,138 subjects aged 40 years or more (47% were men and 34% were employees of companies and local governments) were collected from northern to southern Japan. The prevalence of diagnosed AF in each 10-year age group of both men and women was determined. Based on these prevalence rates and the Registry of Residents, the number of people having AF in Japan was estimated. RESULTS The prevalence rate of AF increased as both male and female subjects aged, and it was 4.4% for men but only 2.2% for women aged 80 years or more (p<0.0001). As a whole, the AF prevalence of men was three times that of women (1.35 versus 0.43%, p<0.0001). There may be approximately 716,000 people (95% confidence interval (CI), 711,000-720,000) with AF in Japan, an overall prevalence of 0.56%. The number of people having AF was projected to be 1.034 (95% CI, 1.029-1.039) million, an overall prevalence of 1.09%, in 2050. CONCLUSIONS The prevalence of AF increased in Japan as the population aged, as in Western countries. The overall prevalence of AF in Japan is approximately two-thirds of that in the USA. The projected increase in the number of people having AF is modest in Japan in 2050.

Long-term Prognosis of Probands with Brugada-pattern ST Elevation in V1-V3 Leads

Background—The prognosis of patients with saddleback or noncoved type (non–type 1) ST-elevation in Brugada syndrome is unknown. The purpose of this study was to clarify the long-term prognosis of probands with non–type 1 ECG and those with coved (type 1) Brugada-pattern ECG. Methods and Results—A total of 330 (123 symptomatic, 207 asymptomatic) probands with a coved or saddleback ST-elevation ≥1 mm in leads V1–V3 were divided into 2 ECG groups—type 1 (245 probands) and non–type 1 (85 probands)—and were prospectively followed for 48.7±15.0 months. The absence of type 1 ECG was confirmed by drug provocation test and multiple recordings. The ratio of individuals with a family history of sudden cardiac death (14%) was lower than previous studies. Clinical profiles and outcomes were not notably different between the 2 groups (annual arrhythmic event rate of probands with ventricular fibrillation; type 1: 10.2%, non–type 1: 10.6%, probands with syncope; type 1: 0.6%, non–type 1: 1.2%, and asymptomatic probands; type 1: 0.5%, non–type 1: 0%). Family history of sudden cardiac death at age <45 years and coexistence of inferolateral early repolarization with Brugada-pattern ECG were independent predictors of fatal arrhythmic events (hazard ratio, 3.28; 95% confidence interval, 1.42 to 7.60; P=0.005; hazard ratio, 2.66; 95% confidence interval, 1.06 to 6.71; P=0.03, respectively, by multivariate analysis), although spontaneous type 1 ECG and ventricular fibrillation inducibility by electrophysiological study were not reliable parameters. Conclusions—The long-term prognosis of probands in non–type 1 group was similar to that of type 1 group. Family history of sudden cardiac death and the presence of early repolarization were predictors of poor outcome in this study, which included only probands with Brugada-pattern ST-elevation.

Three-year follow-up of patients with right bundle branch block and ST segment elevation in the right precordial leads: Japanese registry of Brugada syndrome

Abstract OBJECTIVES We sought to determine the prevalence of right bundle branch block (RBBB) and ST segment elevation in the working Japanese population, as well as the event rate during a three-year prospective follow-up period. BACKGROUND A poor prognosis of RBBB and ST segment elevation has been reported in Europe and South America, even in asymptomatic patients; however, a large population of asymptomatic patients with sporadic RBBB and ST segment elevation has not been studied. METHODS Ten thousand 12-lead electrocardiograms (ECGs) were obtained during annual check-ups of working adults in the Tokyo area. This three-year prospective follow-up study consisted of 105 patients, including 20 with ventricular fibrillation, 18 with syncope and 67 who were asymptomatic. They were registered from 46 institutions in Japan. RESULTS The prevalence of ECG abnormalities in working adults was 0.16%. A coved-type ST segment elevation was related to a history of cardiac events, and 18% of registered patients had PR prolongation and 9.5% had left-axis deviation. The cumulative cardiac event-free rate was 67.6% in the symptomatic group and 93.4% in the asymptomatic group (p = 0.0004) after three years. CONCLUSIONS The recurrence rate of cardiac events in symptomatic patients was similar to that reported previously, but it was very low in sporadic asymptomatic patients. The ECG findings may help us to select patients for further examination and more accurate evaluation of their prognoses.

Characteristics of patients with right bundle branch block and ST-segment elevation in right precordial leads

To elucidate the clinical characteristics of patients with right bundle branch block and ST elevation in the right precordial leads, a prospective follow-up study was made in 63 registered patients, including 17 with a history of ventricular fibrillation (VF) and 14 with a history of syncope. The prevalence of coved type ST elevation was significantly higher in patients who had had cardiac events, and during the initial 15-month follow-up, 2 patients in the VF group died suddenly.

Conversion of Recent-Onset Atrial Fibrillation by a Single Oral Dose of Pilsicainide (Pilsicainide Suppression Trial on Atrial Fibrillation)

The efficacy and safety of a single oral dose of 150-mg pilsicainide, a new class Ic antiarrhythmic drug, in converting recent-onset atrial fibrillation to sinus rhythm were evaluated in 75 patients (51 men, 24 women; age 23 to 74 years). Conversion to sinus rhythm was achieved within 90 minutes in 45% of patients given pilsicainide and in 8.6% of those on placebo (p < 0.01), with no major adverse effects.

Electrical and mechanical alternans in canine myocardium in vivo. Dependence on intracellular calcium cycling.

BackgroundElectrical and mechanical alternans are thought to result from a common cellular mechanism. To confirm this phenomenon in vivo and extend our understanding, we investigated the effects of temperature, verapamil, and caffeine on alternans in intact beating hearts. Methods and ResultsWe recorded surface ECG, monophasic action potential (MAP) using suction electrodes, and left ventricular pressure (LVP). Alternans of MAP configurations and of LVP were evaluated in 20 dogs. MAPs were recorded from the apex, base, and midportion of the left ventricle with LVP. The hearts were driven from the left ventricular apex at a basic cycle length of 1000 milliseconds, and alternans was induced with an abrupt shortening of the cycle length to 400 milliseconds. MAPD30/100, the ratio between the MAP durations (MAPD) at 30%o and 100% repolarization levels, was measured as an index ofMAP configuration. The magnitude ofMAP or LVP alternans was defined as the difference in MAPD30/100 or in LVP between the fifth and sixth paced beats. The magnitude of MAP alternans differed by recording site but correlated with activation time. Lowering the temperature increased the magnitude. MAP alternans was always associated with LVP alternans under control conditions. Verapamil significantly attenuated the magnitude of MAP alternans but did not change that of LVP alternans. Caffeine attenuated the magnitude of both MAP and LVP alternans. T wave alternans was suppressed by verapamil or caffeine. ConclusionActivation time is one of the factors modifying electrical alternans. Delayed intracellular Ca2 cycling plays a role in the concomitant occurrence of electrical and mechanical alternans.

Pharmacokinetics of landiolol hydrochloride, a new ultra‐short‐acting β‐blocker, in patients with cardiac arrhythmias

To elucidate pharmacokinetics and pharmacodynamics of landiolol hydrochloride, newer developed ultra‐short‐acting β‐blocker, in patients with various cardiac tachyarrhythmias.

Randomized trial of angiotensin II-receptor blocker vs. dihydropiridine calcium channel blocker in the treatment of paroxysmal atrial fibrillation with hypertension (J-RHYTHM II Study)

AIMS Atrial fibrillation (AF) is a common arrhythmia frequently associated with hypertension. This study was designed to test the hypothesis that lowering blood pressure by angiotensin II-receptor blockers (ARB) has more beneficial effects than by conventional calcium channel blockers (CCB) on the frequency of paroxysmal AF with hypertension. METHODS AND RESULTS The Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II study) is an open-label randomized comparison between an ARB (candesartan) and a CCB (amlodipine) in the treatment of paroxysmal AF associated with hypertension. Using daily transtelephonic monitoring, we examined asymptomatic and symptomatic paroxysmal AF episodes during a maximum 1 year treatment. The primary endpoint was the difference in AF frequency between the pre-treatment period and the final month of the follow-up. The secondary endpoints included cardiovascular events, development of persistent AF, left atrial dimension, and quality-of-life (QOL). The study enrolled 318 patients (66 years, male/female 219/99, 158 in the ARB group and 160 in the CCB group) treated at 48 sites throughout Japan. At baseline, the frequency of AF episodes (days/month) was 3.8 ± 5.0 in the ARB group vs. 4.8 ± 6.3 in the CCB group (not significant). During the follow-up, blood pressure was significantly lower in the CCB group than in the ARB group (P < 0.001). The AF frequency decreased similarly in both groups, and there was no significant difference in the primary endpoint between the two groups. There were no significant differences between the two groups in the development of persistent AF, changes in left atrial dimension, occurrence of cardiovascular events, or changes in QOL. CONCLUSIONS In patients with paroxysmal AF and hypertension, treatment of hypertension by candesartan did not have an advantage over amlodipine in the reduction in the frequency of paroxysmal AF (umin CTR C000000427).

Chronotropic effects of cilostazol, a new antithrombotic agent, in patients with bradyarrhythmias.

Whether phosphodiesterase inhibitors increase the heart rate in patients with bradyarrhythmias is not known. We attempted to determine whether the oral phosphodiesterase inhibitor cilostazol exhibits beneficial chronotropic effects in patients with symptomatic bradyarrhythmias. Twenty patients comprising eight with bradycardic atrial fibrillation, eight with sick sinus syndrome, and four with Wenckebach-type atrioventricular block, whose 24-h total heart-beat count was < or =70,000 beats and whose maximal RR interval was > or =2.5 s, were enrolled. Holter recordings (24-h) were made before and 2 weeks after oral daily administration of 200 mg of cilostazol. Cilostazol increased the 24-h total heart-beat count from 77,429 +/- 11,168 to 107,981 +/- 13,536 (95% confidence interval, 24,605-36,497; p < 0.0001), the minimal heart rate from 33 +/- 9 47 +/- 13 beats/min (95% confidence interval, 9-19 beats/min; p < 0.0001), and the maximal RR interval from 3,149 +/- 1,018 to 2,087 +/- 601 ms (95% confidence interval, -1,517 to -608 ms; p = 0.0001). Only two patients had headaches as adverse effects. In conclusion, cilostazol had a beneficial positive chronotropic effect in patients with bradyarrhythmias, especially with bradycardic atrial fibrillation and sick sinus syndrome.