ABSTRACT
Objective To assess the difference in left atrial properties between elderly and younger control subjects and the role of left atrium remodeling in patients of different ages with atrial fibrillation.Methods A total of 194 patients with non-valvular atrial fibrillation were enrolled from September 2014 to June 2016.Based on age,patients were divided into an elderly group (≥60 years,n=129) and a younger group (＜60 years,n=65).We evaluated remodeling parameters for the left atrium using an Ultrasound Cardiography (UCG) system in 125 elder subjects,together with 64 control subjects.All remodeling parameters were recorded,including left atrial diameter (LAD),left atrial square (LAS),left atrial pressure (LAP) and left ventricular end-diastolic dimension (LVEDD).Results The elderly group had more female patients and more patients with persistent atrial fibrillation.Meanwhile,scores of CHA2DS2Vsc and levels of N-terminal pro-brain natriuretic peptide (NT-ProBNP) were significantly increased in elderly patients (both P＜0.05).Moreover,the elderly group was associated with increased values of LAD and LAS[(39.1±4.4)mm vs.(37.1±5.3)mm,P＜0.01;and(23.3±4.5)cm2 vs.(21.4±4.8)cm2,P＜0.01;respectively],compared with those in the control group.Spearman's correlation analysis showed that LAD,LAS and LAP were all markedly related to age (r=0.213,P＜0.05;r=-0.175,P＜0.05;r=0.170,P＜0.05;respectively),persistent onset of atrial fibrillation (r=0.401,P＜0.05;r=0.446,P＜0.05;r=0.160,P＜0.05;respectively),and impaired heart function,measured by left ventricular ejection fraction (r=-0.4371,P＜0.05;r=-0.403,P＜0.05;r=-0.364,P＜0.05;respectively) and NT-ProBNP (r=0.485,P＜0.01;r=0.483,P＜ 0.01;r =0.293,P＜ 0.01;respectively).Conclusions Left atrial remodeling properties measured by the UCG system in the elderly with non-valvular atrial fibrillation are more serious than those in mid-aged and young subjects.As a convenient and accurate assessment of remodeling parameters,the UCG system is an excellent option for measuring left atrial remodeling in the elderly population.
ABSTRACT
Objective To investigate characteristics of supraventricular tachycardia affiliated with rate-dependent concealed accessory pathway and the results of radiofrequency catheter ablation (RFCA). Methods Six patients (including 4 females and 2 males, agd from 14 to 68 years) had received electrophysiologic studies and RFCA, which included observing the properties of ventriculoatrial conduction while incremental pacing (S 1S 1) and single extrastimuli (S 1S 2) were performed in right ventricular apex (RVA) and left ventricle (LV), investigating the characteristics of tachycardia, mapping accessory pathway and evaluating the results from RFCA. Results There were 5 left free wall concealed accessory pathways and 1 right concealed accessory pathway at 11 o′clock of tricuspid valve in 6 patients. Five cases were confirmed with 1∶1 ventriculoatrial conduction through the concealed accessory pathway from RVA or LV pacing. The duration of the window ranged from 80 to 100 ms. Four cases were confirmed with accidental retrogradation through the concealed accessory pathway. The supraventricular tachycardia could be induced in 5 cases. All patients were successfully ablated from RVA pacing. Conclusion These results suggest that ventriculoatrial conduction would be rate-dependent because concealed accessory pathway takes place at phase block 3 or 4. In electrophysiologic studies we shoud carefully identify the accidental retrogradation through the concealed accessory pathway to avoid missed diagnosis.