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Introduction We previously reported that LP positive patients after percutaneous coronary intervention (PCI) had higher rate of re-hospitalization in the small-scale study (135 patients). In this study, we evaluated correlation between LP and later cardiac events leading to re-hospitalization more extensively in greater population. Methods and results A 24-h high-resolution (HR) ambulatory electrocardiogram (ECG) was performed in 421 patients that received PCI for the treatment of acute coronary syndrome (ACS) within 30 days. Various baseline characteristics and post-PCI ECG parameters including LP were examined for correlation with later re-hospitalization. LP was evaluated based on 3 different conditions, i.e., the worst, mean and best values, from 24-h signal-averaged QRS wave data. During the post-PCI follow-up period (611 ± 489.0 days), 90 patients were re-hospitalized due to cardiac events. Multivariate analysis identified only positive LP based on the worst value as an independent predictor for re-hospitalization with OR 2.26. Most of re-hospitalization cases (>75%) were predominantly attributed to ischemic events. LP positive population had significantly higher incidences of ischemic events as well as overall re-hospitalization compared to LP negative population. The predictive power of LP was decreased when it was combined with other variables. The receiver operating characteristic analysis determined the LP cut-off values consistent with the LP positive criteria previously reported and standardized. Conclusion The presence of LP in the 24-h HR ambulatory ECG post-PCI was an independent predictor for a risk of re-hospitalization due to ischemic cardiac events in ACS patients.

Objective: Persistent left superior vena cava without bringing vein (PLSVC w/o BV) is a common thoracic venous anomaly, while aberrant left brachiocephalic vein (ALBCV) is an uncommon condition. We compared the incidences of the two venous anomalies and assessed congenital cardiovascular diseases (CCDs) in adults using computed tomography (CT). Materials and Methods: We reviewed the recorded reports or CT images of 49,494 adults for PLSVC w/o BV and ALBCV in two hospitals. We determined incidences of two venous anomalies and the rate of associated CCDs. Results: 76 PLSVCs w/o BV and 27 ALBCVs were found. The incidence of PLSVC w/o BV was 0.15% and the incidence of ALBCV was 0.055%. PLSVC w/o BV had higher incidence than ALBCV (p

Several studies have reported that the left ventricular (LV) lead implant success rate ranges between 88.0% and 92.4%. Coronary venous anatomy differs among patients thus, necessitating multiple types of leads. To date, the implant success rate among Japanese patients utilizing a pre-specified family LV leads (including bipolar and quadripolar) is not well known. The Attain Success Japan Study enrolled patients indicated for a de novo or an upgrade cardiac resynchronization therapy implant. Patients were followed for 3 months, and the implant success rates with Medtronic Attain family LV leads as well as the incidence of complications related to the LV lead were evaluated.Three hundred 53 patients were enrolled from 29 sites in Japan; 346 patients had LV lead implant attempts. The LV lead was successfully implanted in 336 patients (97.1%). Bipolar and quadripolar LV lead implants were successful in 97.2% and 99.2% of patients, respectively (P = 0.43). Four complications (1.2%) related to the LV leads were reported; all of which occurred in patients receiving bipolar LV leads. The quadripolar LV leads were more frequently implanted in the apical segment compared with bipolar leads (21.6% versus 3.8%, P < 0.01). This study demonstrated a high implant success rate and a low LV lead-related complication rate, regardless of bipolar, or quadripolar in a Japanese cohort of patients.

Background Iodine-123 metaiodobenzylguanidine (123 I-MIBG) is useful for detecting sympathetic innervation in the heart, and has been closely associated with fatal arrhythmias. However, such imaging is typically calibrated to the area of highest uptake and thus is unable to identify areas of hyperinnervation. We hypothesized that normal 123 I-MIBG uptake regions in the denervated heart would demonstrate nerve sprouting and correlate with the potential for arrhythmogenesis. Methods Twenty New Zealand white rabbits treated with phenol or sham were prepared under anesthesia. Sympathetic innervation was quantified using autoradiography and immunostaining 4 weeks after phenol application, and electrophysiological study was performed. Results 123 I-MIBG revealed maximal local differences in isotope uptake in the border zone between areas with attenuated and abundant MIBG compared with that seen between adjacent regions within the lowest uptake areas. On immunostaining, heterogeneous and decreased expressions of growth-associated protein 43 signal were observed in the MIBG-attenuated areas; however, abundant signals were recognized in the MIBG-abundant areas. Upregulation of the tyrosine hydroxylase signal was observed at the part of the MIBG-abundant area. In electrophysiological study, the dispersion of activation recovery interval (ARI) was increased in the phenol-applied areas by norepinephrine infusion. Stellate stimulation exacerbated the ARI dispersion in both the phenol-applied and nonapplied areas, and was associated with increased inducibility of ventricular tachycardia and ventricular fibrillation. Conclusions The presence of hyperinnervation in the nondenervated regions of denervated rabbit hearts suggests that heterogeneous neural remodeling occurs in regions with seemingly normal 123 I-MIBG uptake and contributes to electrical instability.

BACKGROUND Sleep-disordered breathing (SDB) is highly associated with arterial hypertension (HT). Sympathetic hypertonia increases the risk of sudden cardiac death in patients with sleep apnea. This study aims to noninvasively investigate the electrophysiological features in SDB patients with and without arterial HT. METHODS Fifty-three patients with SDB were classified into two groups: SDB group and SDB + HT group. Twenty subjects with arterial HT were enrolled as controls (HT group). To assess arrhythmogenic vulnerability, high-resolution 24-hour ambulatory electrocardiograms were obtained for analyzing continuous late potential (LP), T-wave amplitude variability (TAV), and heart rate variability (HRV). RESULTS A higher incidence of positive LP was observed in the SDB + HT (85%) group than that observed in the SDB (50%) and HT (20%) groups (P < 0.01). TAV was highest in the SDB + HT group (78 μV) compared with the SDB (61 μV) and HT groups (42 μV; P < 0.01). Positive LP and TAV values were observed at night in the SDB + HT and SDB groups. The low-frequency/high-frequency of the HRV analysis was highest in the SDB + HT (4.7) group compared with that in the SDB (2.9) and HT (2.9) groups (P = 0.01). CONCLUSION Nocturnal LP, TAV, and HRV examinations were useful to investigate arrhythmogenesis. SDB patients with arterial HT showed a high prevalence of depolarization and repolarization abnormalities and relative sympathetic hyperactivity. This suggests that an electrophysiological instability is more prevalent in SDB patients with arterial HT.

Several studies have reported that the left ventricular (LV) lead implant success rate ranges between 88.0% and 92.4%. Coronary venous anatomy differs among patients thus, necessitating multiple types of leads. To date, the implant success rate among Japanese patients utilizing a pre-specified family LV leads (including bipolar and quadripolar) is not well known. The Attain Success Japan Study enrolled patients indicated for a de novo or an upgrade cardiac resynchronization therapy implant. Patients were followed for 3 months, and the implant success rates with Medtronic Attain family LV leads as well as the incidence of complications related to the LV lead were evaluated.Three hundred 53 patients were enrolled from 29 sites in Japan; 346 patients had LV lead implant attempts. The LV lead was successfully implanted in 336 patients (97.1%). Bipolar and quadripolar LV lead implants were successful in 97.2% and 99.2% of patients, respectively (P = 0.43). Four complications (1.2%) related to the LV leads were reported; all of which occurred in patients receiving bipolar LV leads. The quadripolar LV leads were more frequently implanted in the apical segment compared with bipolar leads (21.6% versus 3.8%, P0.01). This study demonstrated a high implant success rate and a low LV lead-related complication rate, regardless of bipolar, or quadripolar in a Japanese cohort of patients.

Background High-risk patients with Brugada syndrome (BrS) have inherent late potential (LP) fluctuations that might be explained by autonomic activity, electrolyte abnormality, and body temperature changes. However, the correlation between postural changes and LP determinates remains unknown. Methods Forty patients with BrS (38 men, 43.9 ± 13.5 years) and 15 controls (15 men, 42.4 ± 11.2 years) were enrolled. LP variations were investigated at five body positions using high-resolution ambulatory monitoring electrocardiography (HR-ambulatory ECG). The HR-ambulatory ECG was recorded for 3 hours and LP parameters (fQRSd, LAS40, and RMS40) were obtained for at least 15 minutes in each at the supine, left and right lateral decubitus, and prone and sitting positions. Results Determinate LP in the BrS group was significantly abnormal in all positions. Among the five body positions, positive LP were much more frequent in the supine and left and right lateral decubitus positions than in the prone and sitting positions and normalized in the last two positions in patients with BrS. RMS40 variance by postural change was significantly larger in the coved group than in the saddle back group. Determinate LP improved in the sitting position compared to the supine position in the coved group. Conclusions Positive LP findings normalized in the sitting position in patients in the coved BrS group with a resuscitation history, suggesting that depolarization instability might be related to the risk of fatal ventricular arrhythmia. Posture-induced LP variance should be examined using HR-ambulatory ECG analysis in patients with BrS.

Background The impact of regional wall motion abnormality (RWMA) on the accuracy of heart failure with preserved ejection fraction (HFpEF) diagnosis using the E/e′ ratio, which is a non-invasive parameter of left ventricular diastolic performance, is unknown. The purpose of this study was to elucidate the impact of RWMA of the lateral wall (RWMAlat) on the correlation between E/e′ and invasive parameters of left ventricular diastolic performance. Methods Three hundred and eight consecutive patients undergoing tissue Doppler imaging and catheterization pressure examination were retrospectively analyzed. E/e′ was calculated as the ratio of early diastolic transmitral flow velocity to mitral annular velocity at the lateral wall. Invasive parameters including left ventricular end-diastolic pressure (LVEDP) and isovolumetric relaxation time constant (τ) were assessed based on the left ventricular pressure study. Correlation coefficients between E/e′ and these invasive parameters were analyzed and compared between cases with RWMAlat and without RWMA. Results LVEDP and τ correlated well with E/e′ for all 308 patients (r = 0.51 and r = 0.65, respectively). Sixty-two patients had RWMA; the remaining 246 did not have RWMAlat. We confirmed that the presence of RWMAlat weakens both the correlations between E/e′ and LVEDP (r = 0.574 vs. r = 0.381), and E/e′ and τ (r = 0.729 vs. r = 0.461). Conclusions Although E/e′ correlates well with parameters of left ventricular diastolic performance assessed by invasive methods, the presence of RWMAlat worsens this correlation. In cases with RWMAlat, careful assessment is required for HFpEF diagnosis because the diagnostic value of the E/e′ ratio could be decreased compared to patients without RWMAlat.

Iodine-123 metaiodobenzylguanidine (Twenty New Zealand white rabbits treated with phenol or sham were prepared under anesthesia. Sympathetic innervation was quantified using autoradiography and immunostaining 4 weeks after phenol application, and electrophysiological study was performed.The presence of hyperinnervation in the nondenervated regions of denervated rabbit hearts suggests that heterogeneous neural remodeling occurs in regions with seemingly normal

Pulmonary vein isolation (PVI) with radio-frequency catheter ablation (RFCA) is effective therapy for the patients with paroxysmal atrial fibrillation (pAF). However, it is not easy to predict relapse of pAF. Approximately 70% pAF patients were maintained sinus rhythm for 1 year after PVI in Japan. In this study, all of the cases were underwent chest computed tomography (CT) to check for the morphology and positional relationship of the left atrium. We detected relapse cases that exhibited spur formation in the thoracic vertebrae. Therefore, we conducted an investigation based on the hypothesis that, "Because hyperostosis involves proliferative changes in the synovium or pia mater cells with an inflammatory basis, it is related to the onset of atrial fibrillation." The study sample consisted of 24 sequential cases (males: 20, mean age: 66.2 ± 6.9 years) of drug-resistant pAF that underwent PVI at our hospital between January and May, 2015. When subjects were divided into a relapse group and a non-relapse group and 21 background factors were compared, it was found that the relapse group subjects were older than the non-relapse group subjects (70.3 ± 7.2 vs 64.1 ± 5.7, p = 0.04). The proportion of cases with thoracic vertebra hyperplasia was markedly high in the relapse group (6 cases [75%] vs. 3 cases [18%], p = 0.007). No statistically significant differences were observed between the two groups for any other background factors. Our results suggested that thoracic vertebra hyperplasia could be a marker for predicting relapse after PVI in pAF patients.

The aim of this study was to investigate the significance of late potential (LP) after percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS).We enrolled 135 consecutive patients with ACS admitted to Tokai University Hospital from February to December 2012. Twenty-four hour high-resolution ambulatory electrocardiogram was performed between post-PCI procedure and hospital discharge. The patients were divided into the LP-positive (33 patients) and LP-negative (102 patients) groups, and the relationship between LP and re-hospitalization was prospectively investigated.The body mass index, serum creatinine, and creatine phosphokinase-MB were higher in the LP-positive group than in the LP-negative group (p0.05). The re-hospitalization rate was higher in the LP-positive group. (9 patients, 27.3% vs. 10 patients, 9.8%; p = 0.03). There were no significant differences in the occurrence of ventricular tachycardia or cardiac death between the groups. According to Kaplan-Maier analysis, proportion of re-hospitalization was significantly lower in the LP-positive group than in the LP-negative group (p = 0.01; average follow-up, 451.4 ± 25.9 days). The odds ratio of LP presence was 3.45 (highest among all variables; 95% confidence interval, 1.3-9.4; p0.01).Positive LP in patients with ACS after PCI may predict re-hospitalization.

Heart injury due to electric shock is currently diagnosed based on electrocardiogram (ECG) changes or elevated levels of myocardial enzymes or both. However, the rate at which ECG detects abnormalities is very low; thus, the estimated rate of the diagnosis of myocardial damage due to electric shock is lower than the actual rate. The method of nuclear medicine study of the heart is superior with regard to evaluating transient ischemia, such as angina pectoris, in patients whose ECG and myocardial enzyme levels are normal. Therefore, we attempted to diagnose transient myocardial damage in electric shock patients by using nuclear medicine study of the heart.

Sleep-disordered breathing (SDB) is highly associated with arterial hypertension (HT). Sympathetic hypertonia increases the risk of sudden cardiac death in patients with sleep apnea. This study aims to noninvasively investigate the electrophysiological features in SDB patients with and without arterial HT.Fifty-three patients with SDB were classified into two groups: SDB group and SDB + HT group. Twenty subjects with arterial HT were enrolled as controls (HT group). To assess arrhythmogenic vulnerability, high-resolution 24-hour ambulatory electrocardiograms were obtained for analyzing continuous late potential (LP), T-wave amplitude variability (TAV), and heart rate variability (HRV).A higher incidence of positive LP was observed in the SDB + HT (85%) group than that observed in the SDB (50%) and HT (20%) groups (P0.01). TAV was highest in the SDB + HT group (78 μV) compared with the SDB (61 μV) and HT groups (42 μV; P0.01). Positive LP and TAV values were observed at night in the SDB + HT and SDB groups. The low-frequency/high-frequency of the HRV analysis was highest in the SDB + HT (4.7) group compared with that in the SDB (2.9) and HT (2.9) groups (P = 0.01).Nocturnal LP, TAV, and HRV examinations were useful to investigate arrhythmogenesis. SDB patients with arterial HT showed a high prevalence of depolarization and repolarization abnormalities and relative sympathetic hyperactivity. This suggests that an electrophysiological instability is more prevalent in SDB patients with arterial HT.

Background Because nifekalant hydrochloride (NIF) displayed a superior defibrillating effect on ventricular tachycardia/fibrillation (VT/VF) in cardiopulmonary arrest (CPA) patients, despite some QT prolongation, its effect on transmural dispersion of repolarization (TDR) in the left ventricle (LV) in an animal model of CPA was investigated. Methods and Results Eight beagle dogs were created with a myocardial infarction under anesthesia, and then VT/VF induction by continuous stimulation and cardiopulmonary resuscitation (CPR) were repeated. NIF (0.3 mg/kg) was administered under acidotic conditions (pH 7.26). The QTc interval measured by Y-lead ECG showed no significant prolongation before and after NIF. The activation recovery interval (ARI) measured by 64-lead LV surface mapping showed minimum ARI prolongation (40%) by NIF without maximum ARI prolongation, and as a result the ARI dispersion decreased by 67%. The repolarization time (RPT) with the plunge electrode showed 13-19% prolongation in the subendocardium and subepicardium with CPR, but NIF prolonged the RPT in the middle layer alone (17%), and as a result Plunge-TDR decreased by 82% (n=8, p

BACKGROUND: High‐risk patients with Brugada syndrome (BrS) have inherent late potential (LP) fluctuations that might be explained by autonomic activity, electrolyte abnormality, and body temperature changes. However, the correlation between postural changes and LP determinates remains unknown. METHODS: Forty patients with BrS (38 men, 43.9 ± 13.5 years) and 15 controls (15 men, 42.4 ± 11.2 years) were enrolled. LP variations were investigated at five body positions using high‐resolution ambulatory monitoring electrocardiography (HR‐ambulatory ECG). The HR‐ambulatory ECG was recorded for 3 hours and LP parameters (fQRSd, LAS40, and RMS40) were obtained for at least 15 minutes in each at the supine, left and right lateral decubitus, and prone and sitting positions. RESULTS: Determinate LP in the BrS group was significantly abnormal in all positions. Among the five body positions, positive LP were much more frequent in the supine and left and right lateral decubitus positions than in the prone and sitting positions and normalized in the last two positions in patients with BrS. RMS40 variance by postural change was significantly larger in the coved group than in the saddle back group. Determinate LP improved in the sitting position compared to the supine position in the coved group. CONCLUSIONS: Positive LP findings normalized in the sitting position in patients in the coved BrS group with a resuscitation history, suggesting that depolarization instability might be related to the risk of fatal ventricular arrhythmia. Posture‐induced LP variance should be examined using HR‐ambulatory ECG analysis in patients with BrS.

An estimated 50,000 patients have heart failure (HF) in Japan, and the left ventricular ejection fraction (LVEF) is the typical predictor of prognosis. The identification of a noninvasive marker to predict most high-risk patients is urgently needed. This study aimed to log the continuous ventricular late potential (LP) by using high-resolution ambulatory monitoring in patients with HF with non-sustained ventricular tachycardia, and determine the association between the LP variation and prognosis.The 90 hospitalized patients were classified into cardiogenic death (n = 10) and non-death (n = 80) groups. The LVEF, LP, and coefficient of variation (CV) of the filtered QRS (fQRS), and low-amplitude signal40 µV for the terminal QRS portion of (LAS40) of both groups were evaluated. The maximum fQRS over 24 h was defined as the maximum fQRS (Max-fQRS).The results were as follows: (1) cardiogenic death occurred in 32% (10/31 patients) with an LVEF ≤ 45% and a Max-fQRS ≤ 114 ms; (2) cardiogenic death occurred in 38% (10/26 patients) with a LAS40-CV ≥ 0.09; and (3) using LVEF, Max-fQRS, and LAS40-CV as the three predictors, the specificity and accuracy were 83% and 82%, respectively, with an odds ratio of 12.3.LAS40 variations and increases might be new risk indicators of prognosis.

To evaluate the switching from an angiotensin receptor blocker (ARB) to a drug combination containing an ARB and a diuretic drug in terms of effects on hypertension, cardiac load, and cardiac function.In a study conducted on 82 patients with a history of heart failure and hypertension who had been treated with an ARB but failed to reach the target blood pressure, ongoing oral ARB treatment was switched to a drug combination of losartan and hydrochlorothiazide (HCTZ). Using ambulatory blood pressure monitoring (ABPM), the variations in blood pressure and the effects on cardiac load and cardiac function were evaluated before and after treatment.Comparison of the ABPM findings before and after switching treatment showed significant improvements in mean systolic and diastolic blood pressure, improvements in systolic and diastolic blood pressure 1 hour before getting out of bed, and improvements in the plasma levels of human brain natriuretic peptide as an indicator of cardiac load.The drug combination of losartan and hydrochlorothiazide showed a stronger antihypertensive effect than that of the conventional ARB and improved heart function.

Risk stratification is important in the management of Brugada syndrome (BrS). Late potentials (LPs) and T-wave amplitude variability (TAV) in high-resolution ambulatory electrocardiography (ECG) were retrospectively investigated.One hundred and twenty-seven patients diagnosed with BrS on 12-lead ECG were classified into 3 groups: documented ventricular fibrillation (VF)/asystole (n=19), episodes of syncope alone (n=30), and asymptomatic (n=78). Healthy volunteers were enrolled as controls (n=25). In the BrS patients, LPs showed appreciable circadian periodicity; filtered QRS duration (fQRS) and duration of the terminal low-amplitude signal40 μV (LAS40) increased, whereas root mean square voltage of the terminal 40 ms of the fQRS (RMS40) decreased at night compared with the day. TAV did not have such a circadian periodicity. LP-positive incidence (night-time) and peak TAV were as follows: VF/asystolesyncope/asymptomaticcontrol (P0.001). VF/asystole was discriminated from control at a ratio of 81-84% by night-time LPs (fQRS116 ms, LAS4035 ms, RMS4025 μV) or peak TAV (54 μV); VF/asystole was discriminated from syncope/asymptomatic at a ratio of 60-69%, by night-time LPs (fQRS122 ms, LAS4042 ms, RMS4018μV) or peak TAV (58 μV). Combined analysis of LPs and peak TAV increased the discriminant ratio up to 93% and 77%, respectively.Analysis of both LPs and TAV (taking circadian periodicity into account) is useful in identification of high-risk BrS patients.

We determined whether acetylcholine (Ach) application to the pulmonary vein (PV) wall could induce AF and clarified its mechanisms, and determined whether circumferential PV radiofrequency ablation (CPVA) could prevent Ach-induced AF in canine hearts.Thirty seven beagle dogs were used for the study. Ach was injected into the subadventitial layer of the left superior PV (LSPV), at different distance from the LSPV-left atrium junction (LSPV-LA-J) to locate AF initiation. When AF was not induced by Ach alone, programmed electrical stimulation (S1-S2 method) was added to elicit AF. Atropine was injected at the same site of Ach injection to determine whether muscarine-receptor blockade suppressed AF, and CPVA at the LSPV-LA-J was performed using a newly devised basket electrode-catheter.AF was reproducibly induced by Ach injection in 19 of the 26 dogs (73%). S1-S2 method after Ach initiated AF in 5 of the remaining 7 dogs. Ach into the subadventitial layer of the LSPV, especially the distal portion, could elicit AF, which was preceded by pause (sinus arrest) ≥ 2.0 sec (37%) (pause-AF group), sinus bradycardia (32%) (brady-AF group) and sinus tachycardia (32%) (tachy-AF group). The time from Ach injection to AF initiation and AF duration were not significantly different between pause-AF, brady-AF and tachy-AF groups. AF was not initiated by injecting Ach after atropine pretreatment. To eliminate AF, 1-6 (average 4.1 ﾂｱ 1.2) CPVAs at the LSPV-LA-J were required.Our observations suggest that local Ach application can initiate AF in PVs, preceded by a variety of modes such as pause, bradycardia or tachycardia, and an increase in vagal tone at the LSPV plays a critical role in eliciting AF in structurally normal heart.

Because nifekalant hydrochloride (NIF) displayed a superior defibrillating effect on ventricular tachycardia/fibrillation (VT/VF) in cardiopulmonary arrest (CPA) patients, despite some QT prolongation, its effect on transmural dispersion of repolarization (TDR) in the left ventricle (LV) in an animal model of CPA was investigated.Eight beagle dogs were created with a myocardial infarction under anesthesia, and then VT/VF induction by continuous stimulation and cardiopulmonary resuscitation (CPR) were repeated. NIF (0.3 mg/kg) was administered under acidotic conditions (pH 7.26). The QTc interval measured by Y-lead ECG showed no significant prolongation before and after NIF. The activation recovery interval (ARI) measured by 64-lead LV surface mapping showed minimum ARI prolongation (40%) by NIF without maximum ARI prolongation, and as a result the ARI dispersion decreased by 67%. The repolarization time (RPT) with the plunge electrode showed 13-19% prolongation in the subendocardium and subepicardium with CPR, but NIF prolonged the RPT in the middle layer alone (17%), and as a result Plunge-TDR decreased by 82% (n=8, p0.05).Administration of NIF during CPR decreased the TDR by RPT prolongation selectively in the middle layer. Because the subendocardial and subepicardial RPTs after CPR were already prolonged before NIF administration, it may have been the reason why the QT-prolonging effect of NIF was not reflected in the body surface ECG.

To evaluate the short term effects of inhalation of oxygen at night in 51 patients with congestive heart failure (CHF) and sleep apnea syndrome (SAS).Fifty-one patients with stable CHF (31 males, 20 females, mean age 79.0 +/- 11.9 years; brain natriuretic peptide level of100 pg/ml) were evaluated between September 2003 and August 2004, using a Morpheus monitor. The complication rate of SAS in patients with CHF was assessed and apnea hypopnea index, oxygen desaturation index 3%, heart rate, and autonomic nerve activity under room air compared to supplemental O2 (2 l/min) over two consecutive nights.Thirty-eight (75%)of the CHF patients had SAS. Of these SAS patients, 49% suffered from central SAS and 51% had obstructive SAS. Apnea hypopnea index and oxygen desaturation index 3% improved remarkably with supplemental oxygen (p0.001), in particular, the central SAS group demonstrated prominent improvement (p0.001). Obstructive SAS patients exhibited no significant changes (p = 0.3356), but tended to exacerbate the episodes of sleep apnea. Total heart rate was decreased (p = 0.0079). Nevertheless, heart rate variability analysis showed little effect of nocturnal oxygen therapy on the autonomic nervous system during sleeping.Nocturnal oxygen therapy improved the number of sleep apnea episodes and decreased total heart rate during sleep time for the CHF patients with central SAS, despite little influence on the autonomic nervous system, based upon assessment of heart rate variability. Obstructive SAS might exacerbate the episodes of sleep apnea.

Background: Short-term success does not always correlate well with long-term outcome in cases of catheter ablation (CA) for atrial fibrillation (AF). The aim of this study is to examine about the predictor which can differentiate between short- and long-term recurrence of AF after CA of AF. Methods and Results: Total of 52 patients (48; ±9 years, male; 33) were involved. The patients were divided into two groups; Group A: AF recurred earlier than 3 months after CA for AF (35 cases), Group B: AF recurred later than 1 year after CA for AF (17 cases). With multivariate analysis, following parameters were analyzed between Group A and B; diameter of left atrium (LAD) (38.7; ±5.6 vs 40.3; ±9.3 mm, NS), left ventricular ejection fraction (LVEF) (66.0; ±11.9 vs 59.8; ±9.2%, NS), the maximum diameter of pulmonary veins (MDPV) (23.1; ±3.4 vs 25.0; ±2.9 mm, NS), score of CHADS2 (SCHADS) (1.35; ±0.14 vs 1.31; ±0.21, NS), cardiothoracic ration on chest X-ray (CTR) (49.3; ±3.9 vs 51.2; ±4.3, NS) and total number of radiofrequency energy application (RFAP) (62.4; ±11.8 vs 83.9; ±13.8, P

Introduction: We report 2 cases of ventricular arrhythmias (VAs) originating from the left ventricular summit (LVS) which required radiofrequency energy (RF) application in the great cardiac vein (GCV) and/or the epicardium for treating VAs. Case 1: Sixty-five year-old female with idiopathic VAs underwent RF-catheter ablation (CA). The earliest activation site of VAs was observed in GCV, to which left descending coronary artery (LAD) run close. Sufficient RF delivery could not be performed due to the concerns about the injury to LAD, and the procedure resulted in a transient therapeutic effect. Case 2: Fifty-one year-old male suffering from VAs associated with non-ischemic cardiomyopathy underwent RF-CA. In 1st session, the earliest activation site of VAs was recognized in GCV, however, RF-CA application in GCV failed to abolish VAs. In 2nd session with the subxiphoidal pericardial approach, the earliest site was located at LVS extremely close to LAD. Despite the multiple RF applications in the vicinity sites of that portion, we were unable to abolish VAs. Conclusion: In sporadic cases, epicardial approach is required to eliminate VAs. However, the discretion and attention have to be paid in order to avoid the serious complications for treating VAs originating from LVS.

Recently, T-wave variability (TWV) has been notified by Dr. Zareba et al., as attractive marker of repolarization abnormalities. Differing from T-wave alternans which merely observes alternative beat-to beat changes of the amplitude of T-waves, TWV reflects morphological changes of the entire component aspect of ST-T waves by dividing ST-T segment into 40 ms duration for each beat. This method was useful for identifying the high risk patients in myocardial ischemia or dilated cardiomyopathy, however until now there are still few reports about the utility. TWV was measured by the ambulatory monitoring, and therefore a clinical significance might be a great role to capture the repolarization changes during sleep at night. We investigated the longitudinal fluctuations of TWV in the two kinds of disease to stratify risks for fatal arrhythmia. One is Brugada syndrome and the other is sleep apnia syndrome. We used high-resolution ambulatory ECG (2.5 µV, 1000 Hz) manufactured by the Ela Medical company for 24-hours continuously. The data of TWV were analyzed and other electrocardiographic parameters including late potentials (LP), heart rate variability (HRV), heart rate turbulence (HRT), and QT/RR slope were also analyzed using same data. In this symposium, we will report the results of these analyses.

Introduction: The benefit of additional ablation of complex fractionated electrograms (CFE) has been reported in treating patients with persistent atrial fibrillation (per-AF). However, the ideal target patients group for this strategy remains unclear. We report a series of cases with per-AF in which addition of CFE ablation to PVI resulted in successful outcome in freedom from AF. Method and Results: Three patients with symptomatic per-AF (2 with lone AF and 1 with tachycardia-induced cardiomyopathy, AF duration 4–16 months, age 56±6 yrs, 3 male, LA diameter of 43, 46 and 49 mm) under went a single ablation with PVI plus CFE ablation using NavX. The amounts of CFE region were variable (12–34 cm2). However, the distribution was similar among patients (in both the LA roof toward the appendage and LA septum anterior to the right superior PV). All CFE regions were located along area with voltage of 0.5–1.0 mV. Although termination of AF was not achieved, the mean cycle length in the LA significantly prolonged by CFE ablation. Following a single procedure, all three patients remained in sinus rhythm at >4-months follow-up. Conclusion: The details of the clinical and electrophysiological characteristics underlying these three cases will be discussed.

SummaryBackgroundIschemic “pre”-conditioning has been shown to have antiarrhythmic effects. The aim of this study was to investigate whether ischemic “post”-conditioning (post-CON) also has antiarrhythmic effects in ST-segment elevation myocardial infarction (STEMI) patients undergoing coronary angioplasty (PCI) as a clinical model of post-CON.Methods and resultsA total of 61 patients suffering from an acute myocardial infarction (AMI) were included. The QT dispersion (QTd) was measured before each balloon inflation (BI) and after deflation (BD) during PCI. The hemodynamic parameters and electrocardiogram were also assessed during PCI. All data were analyzed using a logistic regression analysis. A total of 36 of 61 STEMI patients could be analyzed according to the protocol. The QTd shortened significantly as the BI and BD were repeated (p

Intravenous amiodarone (AMD) induces multiple antiarrhythmic effects via blocking of Na(+), Ca(2+), and IKr channels, and beta receptors. A patient on chronic dialysis was administered AMD for nonsustained ventricular tachycardia after successful cardiopulmonary resuscitation. QT prolongation occurred 5 h after AMD administration. AMD was withdrawn at 24 h because of prolonged QTc interval (716 ms), which persisted for a further 48 h (661 ms). Ventricular premature contraction (VPC) was significantly decreased at 7h; however, VPC increased again after discontinuing AMD. Depolarization changes induced by the Na(+)-channel blocking action of AMD were analyzed. There was increasing filtered QRS-duration and duration of low-amplitude signals at voltage40 µV, and decreasing root-mean-square voltage of signals in the last 40 ms of ventricular late potentials (LPs) within 7 h. However after stopping AMD, LPs were reversed. The blood concentration of AMD reached the effective level within 10 min but decreased immediately to an ineffective level. Onset and disappearance of the VPC-inhibiting effect corresponded to the depressive effect on depolarization but not with the increase in the prolonged repolarization effect and blood concentration. Even if the QT interval is sufficiently prolonged, the Na(+)-channel blocking action is required for AMD to induce the antiarrhythmic effect.