Target Characteristics and Voltage Mapping of the Matrix in Idiopathic Premature Ventricular Contractions Originating from the Right Ventricular Outflow Tract.

BACKGROUND: The study was aimed at exploring the electrophysiological characteristics (EPS) of the optimal ablation site and its relationship with electroanatomic voltage mapping (EVM) in idiopathic premature ventricular contractions (PVCs) originating from the right ventricular outflow tract (RVOT). METHODS: A total of 28 patients with idiopathic RVOT PVCs underwent successful ablation and EVM using a 3D electroanatomical mapping (CARTO) system. RESULTS: Both bipolar and unipolar EVM showed a similar band-like lower-voltage area (LVA) under the pulmonary valve in all the patients; 21.4% of the targets were located in the band-like LVA. 42.9% of the targets were at the border of the band-like LVA on the bipolar voltage map, but unipolar mapping showed that 53.6% of the targets were located in the band-like LVA, and 35.7% of the targets at the border of the band-like LVA. A significant difference was found in both unipolar and bipolar voltage values between the regions within 0-5 mm above the optimal ablation site and the other regions. A similar difference was observed only in unipolar voltage values below the optimal ablation site. At the ablation site, there were frequent occurrences of a fragmented wave and voltage reversion in the bipolar electrograms, frustrated falling limbs, W bottom, and a QS configuration width > 150 ms in the unipolar electrograms. CONCLUSIONS: EVM showed that the band-like LVA was an interesting area for the search of the optimal ablation sites of idiopathic RVOT-PVCs, especially the border area. There was focal microscarring around the ablation targets; some characteristics of EPS proved significant for successful ablation.

Piperine metabolically regulates peritoneal resident macrophages to potentiate their functions against bacterial infection.

Pepper, a daily-used seasoning for promoting appetite, is widely used in folk medicine for treating gastrointestinal diseases. Piperine is the major alkaloid in pepper and possesses a wide range of pharmacological activities. However, the mechanism for linking metabolic and medicinal activities of piperine remains unknown. Here we report that piperine robustly boosts mTORC1 activity by recruiting more system L1 amino acid transporter (SLC7A5/SLC3A2) to the cell membrane, thus promoting amino acid metabolism. Piperine-induced increase of mTORC1 activity in resident peritoneal macrophages (pMΦs) is correlated with enhanced production of IL-6 and TNF-α upon LPS stimulation. Such an enhancement of cytokine production could be abrogated by inhibitors of the mTOR signaling pathway, indicating mTOR's action in this process. Moreover, piperine treatment protected resident pMΦs from bacterium-induced apoptosis and disappearance, and increased their bacterial phagocytic ability. Consequently, piperine administration conferred mice resistance against bacterial infection and even sepsis. Our data highlight that piperine has the capacity to metabolically reprogram peritoneal resident macrophages to fortify their innate functions against bacterial infection.

Transvenous phrenic nerve stimulation in patients with Cheyne-Stokes respiration and congestive heart failure: a safety and proof-of-concept study.

BACKGROUND: Cheyne-Stokes respiration (CSR), which often occurs in patients with congestive heart failure (CHF), may be a predictor for poor outcome. Phrenic nerve stimulation (PNS) may interrupt CSR in patients with CHF. We report the clinical use of transvenous PNS in patients with CHF and CSR. METHODS: Nineteen patients with CHF and CSR were enrolled. A single stimulation lead was placed at the junction between the superior vena cava and brachiocephalic vein or in the left-side pericardiophrenic vein. PNS stimulation was performed using Eupnea System device (RespiCardia Inc). Respiratory properties were assessed before and during PNS. PNS was assessed at a maximum of 10 mA. RESULTS: Successful stimulation capture was achieved in 16 patients. Failure to capture occurred in three patients because of dislocation of leads. No adverse events were seen under maximum normal stimulation parameters for an overnight study. When PNS was applied following a series of central sleep apneic events, a trend toward stabilization of breathing and heart rate as well as improvement in oxygen saturation was seen. Compared with pre-PNS, during PNS there was a significant decrease in apnea-hypopnea index (33.8 ± 9.3 vs 8.1 ± 2.3, P = .00), an increase in mean and minimal oxygen saturation as measured by pulse oximetry (89.7% ± 1.6% vs 94.3% ± 0.9% and 80.3% ± 3.7% vs 88.5% ± 3.3%, respectively, all P = .00) and end-tidal CO2 (38.0 ± 4.3 mm Hg vs 40.3 ± 3.1 mm Hg, P = .02), but no significant difference in sleep efficiency (74.6% ± 4.1% vs 73.7% ± 5.4%, P = .36). CONCLUSIONS: The preliminary results showed that in a small group of patients with CHF and CSR, 1 night of unilateral transvenous PNS improved indices of CSR and was not associated with adverse events.

Long-term clinical implication of the occurrence of dissociated pulmonary vein activities after circumferential left atrial ablation in patients with paroxysmal atrial fibrillation.

BACKGROUND: The incidence and clinical implication of dissociated pulmonary vein (PV) electrical activities after circumferential antrum PV ablation for paroxysmal atrial fibrillation (AF) remains unclear. METHODS AND RESULTS: A total of 196 patients with symptomatic paroxysmal AF who underwent circumferential antrum PV ablation were prospectively studied. Dissociated PV electrical activities were observed in 101 patients (Group 1), but absent in the remaining 95 patients (Group 2). There were no significant differences in the baseline clinical characteristics between them, except that Group 2 had a higher prevalence of hypertension (30 vs. 44%, P = 0.04). After 21.8 ± 7.9 months of follow-up, 148 had no recurrence of AF after the initial procedure. AF recurrence rate was significantly higher in Group 2 than in Group 1 (P = 0.023). Relapse of PV conduction was the major cause of AF recurrence in both groups (16/16 vs. 19/23, P = 0.08), and the overall procedural success rate after the redo ablation procedure was similar in the 2 groups (90 vs. 86%, P = 0.44). However, the total number of patients with non-PV foci was significantly higher in Group 2 than in Group 1 (12/95 vs. 2/101, P < 0.01). CONCLUSIONS: Dissociated PV electrical activities might identify a subgroup of patients with relatively higher initial procedural success with circumferential PV antrum ablation.