scholarly journals Oral Verapamil Attenuates the Progression of Pacing-Induced Electrical and Mechanical Remodeling of the Atrium

2004 ◽  
Vol 68 (5) ◽  
pp. 494-500 ◽  
Author(s):  
Osamu Kinebuchi ◽  
Hideo Mitamura ◽  
Akiko Shiroshita-Takeshita ◽  
Yasuo Kurita ◽  
Masaki Ieda ◽  
...  
Keyword(s):  
Mechanical Remodeling ◽  
Oral Verapamil

Indicial response functions of growth and remodeling of common bile duct postobstruction

2004 ◽  
Vol 286 (3) ◽  
pp. G420-G427 ◽  
Author(s):  
Quang Dang ◽  
Hans Gregersen ◽  
Birgitte Duch ◽  
Ghassan S. Kassab
Keyword(s):  
Bile Duct ◽  
Common Bile Duct ◽  
Wall Thickness ◽  
Time Course ◽  
Quantitative Description ◽  
Biliary Duct ◽  
Stress And Strain ◽  
Response Functions ◽  
Mechanical Remodeling ◽  
Scheduled Time

Biliary duct obstruction is an important clinical condition that stems from cholelithiasis, the neoplasm in the wall or, most commonly, gallbladder stones. The objective of this study is to understand the structural and mechanical remodeling of the common bile duct (CBD) postobstruction. Porcine CBD was ligated near the duodenum that increased the duct's pressure from 6.4 to 18.3 cmH2O in the first 12 h and to 30.7 cmH2O after 32 days. The remodeling process was studied after 3 h, 12 h, 2 days, 8 days, and 32 days ( n = 5 in each group) after obstruction. One additional animal in each group was sham operated. At each scheduled time, the time course of change of morphometry (diameter, length, wall thickness, etc.) and mechanical properties (stress, strain, etc.) was documented. It was found that the diameter increased by about threefold and the wall thickness of the CBD doubled in the 32-day group compared with the sham group ( P < 0.001). The stress and strain increased initially with increase in pressure but recovered to near the control values by day 32 due to the structural and mechanical adaptations. Hence, the net effect of the structural and mechanical remodeling is to restore the stress and strain to their homeostatic values. Furthermore, the strain recovers more rapidly and more completely than stress. Finally, the remodeling data were expressed mathematically in terms of indicial response functions (IRF), i.e., change of a particular feature of a CBD in response to a unit step change of the pressure. The IRF approach provides a quantitative description of the remodeling process in the CBD.

Differences in Oral Verapamil Absorption as a Function of Time of Day

1989 ◽  
Vol 29 (11) ◽  
pp. 989-993 ◽  
Author(s):  
Michael A. Eldon ◽  
Michele M. Battle ◽  
Ronald E. Voigtman ◽  
Wayne A. Colburn
Keyword(s):  
Time Of Day ◽  
Oral Verapamil

scholarly journals Bachmann bundle impairment following linear ablation of left anterior wall: impact on left atrial function

2020 ◽  
Author(s):  
Yanjuan Zhang ◽  
Fengming Wu ◽  
Yu Gao ◽  
Nan Wu ◽  
Gang Yang ◽  
...  
Keyword(s):  
Contractile Function ◽  
Anterior Wall ◽  
Activation Time ◽  
Linear Ablation ◽  
Measured Activation ◽  
Mechanical Remodeling ◽  
Activation Times ◽  
And Function ◽  
Bachmann Bundle

Background: We aimed to evaluate the effect of Bachmann bundle (BB) impairment on electrical and mechanical function of the left atrium (LA), as well as the long-term clinical impact of such impairment. Design: We measured activation time in the five LA walls in 56 patients with atrial fibrillation. LA reservoir, conduit, and contractile function were also evaluated. Patients were divided into two groups based on ablation strategy: the circumferential pulmonary vein isolation (CPVI) group and CPVI with anterior wall linear ablation (LAWA) group. Patients in the CPVI+LAWA group were divided into two sub-groups based on ECG differences following ablation: the BB impairment group and intact BB group. LA activation time and function were then compared between the ablation strategy groups and the CPVI+LAWA subgroups. Results: Patients in the CPVI+LAWA group exhibited longer activation times in the anterior and lateral walls of the LA, poorer LA synchrony, and reduced LA contractile and reservoir function when compared with those in the CPVI group. In the BB impairment subgroup, we observed a discrepancy between electrical/mechanical remodeling. Among five walls, activation time was longest in this region. BB impairment was also associated with reduced LA function. Conclusion: Significant changes in LA function and conductibility were observed in patients with anterior wall ablation, especially those with iatrogenic BB impairment.

Abstract 1087: Effects of Oral Gap Junction Conduction-Enhancing Antiarrhythmic Peptide GAP-134 on Experimental Atrial Fibrillation in Dogs

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Gabriel Laurent ◽  
Howard Leong-Poi ◽  
Gordon Moe ◽  
Xudong Hu ◽  
Petsy Pui-Sze So ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Gap Junction ◽  
Electrophysiological Study ◽  
Placebo Treatment ◽  
Refractory Periods ◽  
Percent Change ◽  
Dog Model ◽  
Antiarrhythmic Peptide ◽  
The Mean ◽  
Mechanical Remodeling

Background: Abnormal intercellular communication caused by connexin dysfunction may promote atrial fibrillation (AF). Objective: To assess the effect of the gap junction conduction-enhancing antiarrhythmic peptide GAP-134 on AF inducibility and maintenance in a new dog model of atrial cardiomyopathy. Methods and Results: Twenty four dogs underwent simultaneous atrioventricular pacing (2 weeks at 220 bpm, atrioventricular delay 0 ms), and were randomly assigned to placebo treatment (PACED-PLACEBO; 12 dogs) or oral GAP-134 (PACED-GAP 134; 12 dogs) (starting at day 0). Percent change in left atrial systolic area (Δ% LASA) from baseline to 2 weeks was calculated using trans-esophageal echocardiography. At 2 weeks, animals underwent an open chest electrophysiological study; conduction velocity (CV) when pacing at 150ms cycle length (CL), effective refractory periods (ERP) and AF vulnerability were measured. The mean plasma concentration of GAP-134 was 557 ± 239 nmol/L. GAP-134 increased CV (395.1 ± 63.2 vs 307.8 ± 54.6 mm/s, p<0.01), and shortened ERP at 200ms CL (104.0 ± 8.6 vs 112.8 ± 11.5 ms, P<0.05). GAP-134 significantly reduced AF inducibility [% burst attempts inducing AF] and maintenance [mean AF duration, number of episodes >10min] in dogs with less than 100% ΔLASA (n=5). In dogs with more structural remodeling (ΔLASA ≥100%, n=7), CV increased but AF inducibility was unaffected. Conclusions: Oral GAP-134 prevents CV slowing in a dog model of atrial cardiomyopathy, but attenuates AF inducibility and maintenance only in dogs with less mechanical remodeling.

Sign in / Sign up

Export Citation Format

Share Document