上岡 正志

AIMS: The relationship between local unipolar voltage (UV) in the pulmonary vein (PV)-ostia and left atrial wall thickness (LAWT) and the utility of these parameters as indices of outcome after atrial fibrillation (AF) ablation remain unclear. METHODS AND RESULTS: Two-hundred seventy-two AF patients who underwent AF ablation were enrolled. Unipolar voltage of PV-ostia was measured using a CARTO system, and LAWT was measured using computed tomography. The primary endpoint was atrial tachyarrhythmia (ATA) recurrence including AF. The ATA recurrence was documented in 74 patients (ATA-Rec group). The UV and LAWT of the bilateral superior PV roof to posterior and around the right-inferior PV in the ATA-Rec group were significantly greater than in patients without ATA recurrence (ATA-Free group) (P < 0.001). The UV had a strong positive correlation with LAWT (R2 = 0.446, P < 0.001). The UV 2.7 mV and the corresponding LAWT 1.6 mm were determined as the cut-off values for ATA recurrence (P < 0.001, respectively). Multisite LA high UV (HUV, ≥4 areas of >2.7 mV) or multisite LA wall thickening (≥5 areas of >1.6 mm), defined as LA hypertrophy (LAH), was related to higher ATA recurrence. Among 92 LAH patients, 66 had HUV (LAH-HUV) and the remaining 26 had low UV (LAH-LUV), characterized by history of non-paroxysmal AF and heart failure, reduced LV ejection fraction, or enlarged LA. In addition, LAH-LUV showed the worst ablation outcome, followed by LAH-HUV and No LAH (log-rank P < 0.001). CONCLUSION: Combining UV and LAWT enables us to stratify recurrence risk and suggest a tailored ablation strategy according to LA tissue properties.

BACKGROUND: To investigate the clinical implication of the temporal difference in atrial fibrillation (AF)-onset in acute decompensated heart failure (ADHF) and its impact on post-discharge prognosis. METHODS: 336 new-onset ADHF patients without any history of AF before admission were enrolled (201 males, 63 ± 16 year-old) and classified into two groups based on their history of AF: the Control group (No AF was detected during hospitalization, n = 278), and the In-hos-AF group (AF occurred during hospitalization, n = 58). Post discharge prognosis including rehospitalization due to worsening HF, cardiac death, all-cause death and cerebrovascular event were compared. RESULTS: Kaplan-Meier analysis demonstrated that the incidence of rehospitalization due to HF, cardiac death, all-cause death and cerebrovascular event in the In-hos-AF group was not significantly different from that in the Control group (P > 0.05 respectively). However, when AF recurred in the In-hos-AF group patients (n = 24, 41%) after discharge, the incidence of rehospitalization due to HF and cardiac deaths were higher than those without AF recurrence (P = 0.018 and P = 0.027 respectively). Cox proportional analysis revealed that AF developing after discharge was proven to be an independent risk factor for rehospitalization due to HF (HR 1.845, P = 0.043), cardiac death (HR 3.562, P = 0.013) and all-cause deaths (HR 2.138, P = 0.020). CONCLUSION: Clinical outcomes of new-onset in-hospital AF patients were as good as those without AF history until AF recurrence. However, AF recurrence led to worse prognosis. Therefore, treatment for new-onset in-hospital AF in ADHF patients might be postponed until AF recurrence.

BACKGROUND: The mechanism of esophageal thermal injury (ETI; esophageal mucosal injury and periesophageal nerve injury leading to gastric hypomotility) remains unknown when using a high-power short-duration (HP-SD) setting. This study sought to evaluate the characteristics of esophageal injuries in atrial fibrillation ablation using a HP-SD setting. METHODS: After exclusion of 5 patients with their esophagus at the right portion of left atrium and 21 patients with additional ablations such as box isolation and low voltage area ablation in left atrium posterior wall, 271 consecutive patients (62±10 years, 56 women) who underwent pulmonary vein isolation by radiofrequency catheter ablation were analyzed. In the 101 patients, a HP-SD setting at 45 to 50 W with an Ablation Index module was used (HP-SD group). In the remaining 170 patients before introduction of the HP-SD setting, a conventional power setting of 20 to 30 W with contact force monitoring was used (conventional group). We performed esophagogastroduodenoscopy after pulmonary vein isolation in all patients and investigated the incidence and characteristics of ETI. RESULTS: Although the incidence of ETI was significantly higher in the HP-SD group compared with the conventional group (37% versus 22%, P=0.011), the prevalence of esophageal lesions did not differ between the groups (7% versus 8%). Multivariate logistic regression analysis revealed that the use of the HP-SD setting (odds ratio, 6.09, P<0.001), and the parameters that suggest anatomic proximity surrounding the esophagus, were independent predictors of ETI. However, the majority of ETI in the HP-SD group was gastric hypomotility, and the thermal injury was limited to the shallow layer of the periesophageal wall using the HP-SD setting. CONCLUSIONS: Although the use of the HP-SD setting was a strong predictor of ETI, it could avoid deeper thermal injuries that reach the esophageal mucosal layer.

BACKGROUND: Cardiac amyloidosis (CA) is characterized by left ventricular hypertrophy (LVH) and autonomic nervous imbalance due to amyloid infiltration. However, autonomic dysfunction is often seen in heart failure (HF) with LVH from other etiologies. We aimed to characterize autonomic dysfunction in CA from other etiologies of LVH. METHODS: Fifty-five HF patients with LVH (35 males, mean age 65 ± 16 years) were enrolled. LVH was defined as left ventricular mass index measured by echocardiography >95 g/m2 in women and 115 g/m2 in men. The etiology was as follows: amyloid light chain (AL)-CA, n = 14; hypertrophic cardiomyopathy, n = 21; and aortic stenosis (AS), n = 20. With the patient in a clinically stable condition, heart rate variability (HRV) and heart rate turbulence (HRT), which reflect autonomic dysfunction, were measured using Holter monitoring and compared among the three groups. RESULTS: Brain natriuretic peptide levels, LVH severity, left ventricular ejection fraction, and tissue Doppler index E/e' did not differ among the three groups. However, severe abnormalities of HRV and HRT were obtained in AL-CA. In the ROC analysis to identify AL-CA in HF with LVH, the best cutoff value for standard deviation of all R-R intervals, standard deviation of the 5-min mean R-R intervals, turbulence onset, and turbulence slope were 68.5 ms (AUC: 0.865), 58.5 ms (AUC: 0.834), 0.25% (AUC: 0.813), and 1.00 ms/RR (AUC 0.736), respectively. CONCLUSION: Autonomic dysfunction is a hallmark of AL-CA, and its noninvasive assessment by Holter monitoring may be a useful tool for differential diagnosis of HF with LVH.

BackgroundIn catheter ablation of idiopathic ventricular arrhythmia (VA), it is still unclear whether pace mapping or activation mapping is more useful for successful catheter ablation. The depth of origin in the ventricular wall especially affects the success rate of endocardial-approached catheter ablation. Thus, we examined the relationship between these tactics and QRS morphology. MethodsWe evaluated the relationship among pace mapping score, activation time, and peak deflection index (PDI) in 28 patients, with a total of 30 origins, who underwent successful catheter ablation of idiopathic VA. ResultsAll origins were located in the ventricular outflow tract area, including three in the left coronary cusp (LCC). PDI, activation time, and pace mapping score at successful ablation sites were 0.60 0.08, 26.3 +/- 9.9 ms, and 19.1 +/- 4.6, respectively. The pace mapping score inversely correlated with the PDI (R = -0.540, P = 0.0017), but the activation time did not correlate with the PDI. When excluding the three VAs originating from the LCC, in which perfect pace mapping was obtained from epicardial sites despite high PDI, this correlation coefficient became more intensive (R = -0.734, P &lt; 0.0001). ConclusionsOur study suggests that pace mapping with an endocardial approach could not reproduce the precise QRS morphology for VA originating from the intramural site of the ventricular wall. With such origins, we should rely on activation mapping to detect the optimal ablation site.

Backgrounds: Although acute decrease of intrathoracic impedance measured by cardiac resynchronization therapy (CRT) is effective to detect pulmonary congestion, it is unclear about the association with long-term change of intrathoracic impedance and left ventricular (LV) function in chronic heart failure (CHF) patients with CRT. Methods: Twenty six CHF patients who received CRT-defibrillator (CRT-D) were enrolled. LV dimensions, LV ejection fraction (LVEF) and B-type natriuretic peptide (BNP) were measured before and 6 months after CRT-D implantation. LV reverse remodeling was defined as >15% reduction in LV end-systolic volume after 6 months. In addition, intrathoracic impedance at 1 and 6 months after CRT-D implantation was investigated. The study subjects were divided into 2 groups: 18 patients with increased levels of intrathoracic impedance (Group-A) and 8 patients with decreased (Group-B). We compared LVEF, BNP levels and LV reverse remodeling between two groups. Results: In Group-A, BNP levels decreased and LVEF increased at 6 months after CRT-D implantation (P=0.01, each). In contrast, BNP levels and LVEF did not change in group-B. In Group-A, 15 patients (83%) were classified as LV reverse remodeling despite of 3 patients (37%) in Group-B (P=0.01). Conclusions: These results suggest that long-term increase of intrathoracic impedance is a novel predictor for LV reverse remodeling in CHF patients with CRT.

Backgrounds: It has been recently shown that the monitoring of changes in Fluid Index (FI) calculated by intrathoracic impedance with cardiac resynchronization therapy (CRT) may be useful for early detection of decompensated heart failure (DHF). However, the relation of changing pattern in FI and DHF remains uncertain, because several factors other than pulmonary congestion may affect on intrathoracic impedance. Therefore, we investigated this issue in order to predict the manifestation of DHF correctly. Methods and Results: We studied 26 chronic heart failure patients (19 males, mean age 66±11 years) who had implanted CRT-defibrillator with impedance monitoring. In the observation term (10.9±4.2 months), 20 patients experienced 48 episodes of FI over 60ω-days. These episodes were divided into two groups whether medical treatment for DHF was required (group A, n=21) or not (group B, n=27). Based on daily FI, we determined linear approximate equation (Y=aX, Y: daily FI, a: the slope of increasing FI, X: the days from the beginning of increasing FI to crossing 60ω-days). We next compared the slope of increasing FI between two groups. The slope of increasing FI was significantly steeper in group A than in group B (3.68±0.88 vs. 2.84±0.96, P<0.01). Conclusions: These results suggest that the monitoring of the slope of increasing FI was helpful for predicting patients with DHF.

Sympathetic activation plays a critical role of Cheyne-Stokes respiration (CSR) with chronic heart failure (CHF) and has associated with adverse clinical outcome. Recently, several studies have shown that adaptive servo ventilation (ASV) therapy improves the prognosis of CHF patients with CSR. However, it remains unclear the effect of ASV on sympathetic nervous activity. A case is a 50's dilated cardiomyopathy man. He was diagnosed as severe CSR by polysomnography and treated with ASV. We performed new multifunction wireless holter ECG (CarPod^R) before and after ASV therapy, which is able to evaluate the heart rate variability, physical activity, body temperature and etc. ASV improved apnea hypopnea index (63.8/h to 12.1/h) and slow wave sleep (2.3% to 3.4%). In addition, ASV decreased the occurrence of PVC (0.07% to 0.04%), LF/HF (2.7 to 1.3 during sleeping, 5.2 to 4.2 during awaking) and heart rate increase index (33.9 to 15.3), and also increased physical activity in the daytime. These results obtained from new multifunction wireless holter ECG suggest that ASV might improve not only sympathetic function but also physical performance in CHF patients with CSR.

Backgrounds: It has been shown that the position of left ventricular (LV) pacing lead and viability of the LV wall may affect on the response to cardiac resynchronization therapy (CRT). However, little is known about the association between characteristics of LV pacing lead and LV reverse remodeling in chronic heart failure (CHF) patients with CRT implantation. Methods: The study subjects consisted of 32 CHF patients (23 males, mean age, 64±11 years) with CRT-defibrillator (CRT-D) implantation. We measured LV end-systolic volume (LVESV) by echocardiography before and 6 months after CRT-D implantation and defined the CRT responder as >15% reduction of LVESV at 6 months. The patients were divided into 2 groups based on CRT responder (group-A, n=20) or not (group-B, n=12). We compared the LV R-wave amplitude at CRT-D implantation and the change of LV pacing threshold 6 months after CRT-D implantation between 2 groups. Results: LV R-wave amplitude did not differ between 2 groups (A, 15.1±8.1 mV vs. B, 14.5±8.6 mV). In addition, the change in LV pacing threshold was similar between two groups (improving: 5% vs. 8%; worsening: 25% vs. 25%). Conclusions: These results suggest that electrophysiological properties of regional left ventricle at CRT implantation site do not predict the LV reverse remodeling in response to CRT in CHF patients.