Study Subjects The retrospectively enrolled subjects were 151 patients with PAH in the Nice Classification group 1 who were admitted for routine hemodynamic follow-up and were screened for SDB from April 2008 through February 2010 (37 males, 114 females; 44±16 years old). The mean PAP (mPAP) was 46±16 mmHg, and PVR was 12±9 Wood units. Patients with a total sleep time <3 h in the sleep studies were excluded. PAH was defined by right-heart catheterization (RHC) as mPAP ≥25 mmHg with a pulmonary artery wedge pressure (PAWP) <15 mmHg. They were classified, on the basis of the Nice Classification; into idiopathic PAH (IPAH; n=78) and associated PAH (n=73) (52% and 48 %, respectively). There were 6 patients with Eisenmenger syndrome in the associated PAH group. Assessments Serum hemoglobin (Hb) and B-type natriuretic peptide S leep apnea (SA) can cause repeated nocturnal arterial oxygen desaturation, sleep fragmentation, increased sympathetic activity, oxidative stress, inflammation and endothelial dysfunction, negative swings in intrathoracic pressure, and acute increase in pulmonary arterial pressure (PAP). 1-5 Pulmonary vasoconstriction occurs in response to alveolar hypoxia, then increased pulmonary vascular resistance (PVR), contributing to an increase in PAP and resulting in pulmonary vascular remodeling. 6,7 Sleep-disordered breathing (SDB) in patients with pulmonary arterial hypertension (PAH), which comprises not only SA, but also periodic breathing and nocturnal hypoxemia, is common. 8-14 Many studies show that the presence of SA is associated with a poor prognosis in patients with left-sided heart failure, 15,16 but the effect of nocturnal hypoxemia and SA on the outcome of patients with PAH is unknown. The objective of the present study, therefore, was to determine whether nocturnal hypoxemia and/or SA is associated with prognosis in PAH patients.

ObjectiveRecently, concern has increased regarding the hazards of radiation exposure in patients and laboratory staff. Since the numbers of complex catheter ablations (CA) performed, duration of procedure times, and need for multiple sessions have increased, radiation exposure during each session needs to be minimised. Our study aimed to assess the impact of awareness on radiation exposure during CA for atrial fibrillation (AF).MethodsMini-course lectures was delivered to the physicians and staff in the electrophysiology division. Its effect on the fluoroscopic time and radiation dose during AF ablation before (Group I, n=70), shortly after (Group II: n=70) and remotely after the mini-lecture (Group III, n=70) were evaluated. Patient demographics, preoperative testing and procedural parameters were collected.ResultsThe fluoroscopic time significantly reduced after the lecture (Group I and II: 25.1±10.0 and 15.1±7.3 min, respectively (p<0.0001)), and remained so in Group III (13.0±5.4 min), despite the increase in the number of persistent AFs. The radiation dose also significantly reduced (Groups I, II, III: 295.0±263.0, 109.6±103.5 and 110.1±89.6 mGy, respectively (p<0.0001)).ConclusionAwareness on radiation exposure led to a significant reduction in fluoroscopic time and radiation dose during CA for AF, the effect of which persisted even to remote periods following the procedure.

BackgroundThere are no criteria for selecting single- or dual-chamber implantable cardioverter defibrillators (ICDs) in patients without a pacing indication. Recent reports showed no benefit of the dual-chamber system despite its preference in the United States. As data on ICD selection and respective outcomes in Japanese patients are scarce, we investigated trends regarding single- and dual-chamber ICD usage in Japan.MethodsData from a total of 205 ICD recipients with structural heart disease (median age, 63 years) in two Japanese university hospitals were reviewed. Patients with bradycardia with a pacing indication and permanent atrial fibrillation at implantation were excluded.ResultsSingle- and dual-chamber ICDs were implanted in 36 (18%) and 169 (82%) patients, respectively. Non-ischemic cardiomyopathy dominated both groups. Seventeen dual-chamber patients developed atrial pacing-dependency over 4.5 years, and it developed immediately after implantation in 14. Although preoperative testing showed no sign of bradycardia in these patients, their pacing rate was set higher than it was in patients who were pacing-independent (61 vs. 46 paces per min, p<0.01). Two single-chamber patients (5%) underwent atrial lead insertion.While inappropriate shock equally occurred in both groups (7 vs. 21 patients, single- vs. dual-chamber, P=0.285), device-related infection occurred only in dual-chamber patients (0 vs. 9 patients, P=0.155). No differences in death or heart failure hospitalization were observed between groups.ConclusionsDual-chamber ICDs were four-fold more common in Japanese patients without a pacing indication. No benefit over single-chamber ICD was observed. Newly developed atrial pacing-dependency seemed to be limited and could have been overestimated due to higher pacing rate settings in dual-chamber patients.

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A novel, sensor-based, electromagnetic, non-fluoroscopic catheter visualization (NFCV) system shows tracked catheters directly on pre-acquired fluoroscopy or cine loops. We aimed to evaluate the effectiveness of this system in the setting of catheter ablation for idiopathic premature ventricular contractions/ventricular tachycardia (i-PVC/VT). A total of 30 i-PVC/VT ablation procedures were performed using the NFCV system in conjunction with three-dimensional electroanatomic mapping system (3D-EMS) between January 2013 and April 2017. At the beginning of the procedure, cine loops of right and left anterior oblique views were obtained and replayed for subsequent mapping and ablation. Right ventriculography, aortography, or coronary angiography was performed, depending on the chamber of interest. We reviewed procedural parameters, comparing with the i-PVC/VT ablation procedure using conventional fluoroscopy (CvF) system (pre-, and post-NFCV implementation; 20 and 11 cases, respectively). I-PVC/VTs were successfully eliminated in 26 patients (87%) in the NFCV group and in 26 (84%) in the CvF group (P = 1.000). The procedure time in the NFCV group was comparable to that in the CvF group (119.8 versus 125.0 minutes, respectively, P = 0.868); the total fluoroscopy time was significantly shorter in the NFCV group (3.3 versus 16.6 minutes, P < 0.001). One patient in the CvF group experienced cardiac tamponade, requiring pericardial drainage. No major complications were encountered in the NFCV group. NFCV system, in conjunction with 3D-EMS, was safe and feasible for i-PVC/VT mapping and ablation. The system contributed to dramatically reduced fluoroscopy time, compared with CvF.