Dong Chang

The Early Stage of the Atrial Electroanatomic Remodeling as Substrates for Atrial Fibrillation in Hypertensive Patients

Background Hypertension is one of the most important risk factors for atrial fibrillation (AF). Recent studies suggest right atrial remodeling in hypertensive patients may be associated with increased inducibility of AF. This study sought to characterize the electroanatomic features of left and right atria and pulmonary veins (PVs) in hypertensive patients. Methods and Results A prospective observational study was conducted on patients who underwent ablation for paroxysmal supraventricular tachycardia or paroxysmal AF. Electrophysiological features of the PVs and atria, including event‐related potentials, conduction time, and inducibility and vulnerability of AF, were characterized during cardiac catheterization. Anatomic and hemodynamic features were assessed by using echocardiographic and computer tomography imaging. When 15 hypertensive patients with paroxysmal supraventricular tachycardia were compared with 17 normotensive patients with paroxysmal supraventricular tachycardia, the hypertensive patients had significantly shortened PV event‐related potentials with increased dispersions (P<0.001) but slightly prolonged atrial event‐related potentials (P=NS) and had prolonged interatrial and intra‐atrial conduction times (P<0.001). Additionally, the hypertensive patients had increased vulnerability and inducibility of AF and prolonged duration of induced AF (P<0.01). All of these changes were more pronounced in hypertensive patients with paroxysmal AF. Anatomically, compared with the normotensive patients, the diameters of 4 PVs in the hypertensive patients with paroxysmal supraventricular tachycardia were significantly enlarged (P<0.01) and became more remarkable in hypertensive patients with paroxysmal AF (P<0.0001), although the diameter and volume index of the left atrium among 3 groups were similar. Conclusions The hypertensive patients showed electroanatomic changes associated with increased vulnerability to AF, including shortened event‐related potentials with increased dispersion, prolonged conduction time, and increased PV diameter, but these changes were not appreciated in the atria. Additionally, these changes became more dramatic in hypertensive patients with paroxysmal AF.

Atrial fibrillation is related to lower incidence of deep venous thrombosis in patients with pulmonary embolism

Background Atrial fibrillation (AF) is an established risk factor of left atrial thrombosis and systemic embolism. Traditionally pulmonary embolism (PE) is a recognized complication of deep vein thrombosis (DVT). However, whether AF is responsible for right atrial thrombosis and leads to PE has not been examined. Methods We retrospectively analyzed medical records of patients with confirmed diagnosis of PE with AF (study group) from 2002-2015. Patients with PE without AF, matched by age and sex, served as controls (control group). The CHA2DS2-VASc and CHADS2 scores were classified into two categories, low-intermediate (<2 points) and high-risk (≥2 points). Results A total of 330 patients (110 in study group and 220 in control group). The study group had significantly lower incidence of newly diagnosed DVT (21% vs. 44%, P<0.001), previous history of DVT (6% vs. 17%, P=0.006) and recent surgery or trauma (10% vs. 23%, P=0.004) compared to the control group. When stratified by the CHADS2 score, 49 patients (44.5%) were considered low-intermediate risk. This proportion significantly differed when stratified using CHA2DS2-VASc, in which 13 patients (13.6%) were considered low-intermediate risk, P<0.001. Conclusions The incidence of DVT was much lower in the study group, suggesting the possibility of clots originated from the right heart that may increase the risk of PE. The CHA2DS2-VASc scoring system might be more sensitive for prediction and stratification of the PE in AF patients than the CHADS2 score.

Frequency Gradient Within Coronary Sinus Predicts the Long‐Term Outcome of Persistent Atrial Fibrillation Catheter Ablation

Background The coronary sinus (CS), as a junction of the atria, contributes to atrial fibrillation (AF) by developing unstable reentry, and isolating the atria by ablation at the CS could terminate AF. The present study evaluated whether AF activities at the CS in a subset of patients contributed to AF maintenance and predicted clinical outcome of ablation. Methods and Results We studied 122 consecutive patients who had a first‐time radiofrequency ablation for persistent AF. Bipolar electrograms were obtained from multiple regions of the left atrium by a Lasso mapping catheter before ablation. Pulmonary vein isolation terminated AF in 12 patients (9.8%). Sequential stepwise ablation was conducted in pulmonary vein isolation nontermination patients and succeeded in 22 patients (18%). In the stepwise termination group, AF frequency in the proximal CS (CSp) was significantly higher (10.2±2.1 Hz versus 8.3±1.8 Hz, P<0.001), and the ratio of distal CS (CSd) to proximal CS (CSd/CSp ratio, 56.6%±10.11% versus 70.7%±9.8%, P<0.001) was significantly lower than that in the nontermination group. The stepwise logistic regression analysis indicated that the CSd/CSp ratio was an independent predictor with an odds ratio of 1.131 (95%CI 1.053‐1.214; P=0.001). With a cutoff of 67%, the patients with lower CSd/CSp ratios had significantly better index and long‐term outcomes than those with higher ratios during a follow‐up of 46±18 months. Conclusions Rapid repetitive activities in the musculature of the proximal CS may contribute to maintenance of AF after pulmonary vein isolation alone in persistent AF. A cutoff at 67%, of the CSd/CSp frequency ratio might be an indicator to stratify the subset of patients who might benefit from CS ablation.

P-183 Autonomic Nerve Denervation Contributes to the Long-Term Efficacy of Circumferential Pulmonary Vein Ablation on Atrial Fibrillation

between regional oxygen delivery and oxygen consumption in the cerebral tissue. We observed 110 pts (65 women) aged 18 52 yrs, VVS referred to HUTT. Methods: All pts underwent HUTT performed according to Westminster or Italian protocols. During HUTT the rSO2 of frontal lobes of brain was measured using INVOS cerebral oximeter. Baseline value of rSO2 was evaluated during 15 minutes supine phase before HUTT. Changes of rSO2 during HUTT a degree of relative decrease (in %) of rSO2 were measured. Area limited by curve of rSO2 and baseline level of rSO2 during last 3 minutes of HUTT (ACCO) was also analysed in all patients. Results: During upright position a down-step decrease of rSO2was observed (7 15%). An exaggeration of desaturation, usually with concomitant hyperventilation, followed by short-time (20 180 s) significant (>25%) desaturation preceded syncope in patients with positive HUTT. Mean value of cerebral desaturation ( 31.8 vs 9.0%) and ACCO ( 42.0 vs 11.1%·min) were significantly higher in HUTT-positive pts in comparison to non-fainters. There were no differences between all types of vaso-vagal response. Conclusions: 1. Mild cerebral desaturation took place during passive tilting both in patients with positive and negative results of head-up tilt test. 2. Significant desaturation with hyperventilation preceded the occurrence of syncope in patients with positive head-up tilt test.