scholarly journals Heart rate in patients with reduced ejection fraction: relationship between single time point measurement and mean heart rate on prolonged implantable cardioverter defibrillator monitoring

2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Marlena V. Habal ◽  
Kumaraswamy Nanthakumar ◽  
Peter C. Austin ◽  
Cassandra Freitas ◽  
Christopher Labos ◽  
...  
2020 ◽  
Vol 9 (4) ◽  
pp. 1111 ◽  
Author(s):  
Vincenzo Russo ◽  
Roberta Bottino ◽  
Anna Rago ◽  
Andrea Antonio Papa ◽  
Biagio Liccardo ◽  
...  

Sacubitril/valsartan therapy reduces sudden cardiac death (SCD) among patients with reduced ejection fraction (HFrEF) when compared to guidelines recommended doses of enalapril, however the mechanism is still not clear. There are few, contrasting results about the effect of sacubitril/valsartan on arrhythmias in the clinical context of dilated cardiomyopathy (DCM) and there are no clinical data about its effect on measured implantable cardioverter defibrillator (ICD) electrical parameters, such as atrial/ventricular electrograms sensing and pacing threshold. We conducted a 12 month follow-up observational study in 167 ischemic and nonischemic DCM patients (mean age 68.1 ± 11.6 years; 85% male), with dual-chamber ICD on sacubitril/valsartan treatment, to evaluate the incidence of device detected tachyarrhythmia events, both atrial and ventricular, and the change in measured ICD electrical parameters. We collected data on clinical, electrocardiographic and echocardiographic parameters to find a possible electro-mechanical correlation within results. Our results show that DCM patients with reduced ejection fraction and ICD on sacubitril/valsartan treatment experienced a reduction in both atrial and ventricular arrhythmias incidence and an improvement in ICD electrical atrial parameters. The findings might be explained by the electro-mechanical cardiac reverse remodeling induced by sacubitril/valsartan therapy.


2007 ◽  
Vol 6 (5) ◽  
pp. 7290.2007.00031 ◽  
Author(s):  
Shingo Baba ◽  
Steve Y. Cho ◽  
Zhaohui Ye ◽  
Linzhao Cheng ◽  
James M. Engles ◽  
...  

To determine the most robust and reproducible parameters for noninvasively estimating tumor cell burden in a murine model, we used real-time in vivo bioluminescent imaging to assess the growth kinetics and dissemination of luciferase-transfected Raji B-cell lymphoma. Bioluminescent signals were acquired every minute for 40 minutes after luciferin injection every other day post-tumor injection. The total 40-minute area under the curve (AUC) of photon intensity (photons/second) was calculated and compared with simplified fixed time point observations (every 5 minutes from 5 to 40 minutes after substrate injection). There was substantial variability in the shape of the time signal intensity curves at different stages of tumor growth in both the intravenous and subcutaneous models. The coefficient of variance in the AUC was 0.27 (intravenous) and 0.36 (subcutaneous) as values determined by fitting the curve, whereas the 20-minute time point measurement varied at 0.29 (intravenous) and 0.37 (subcutaneous). In both the subcutaneous and intravenous models, single time point measurements at 20 minutes had the highest correlation value with AUC. This simplified single time point measurement appears appropriate to estimate the total tumor burden in this model, but the substantial variance at each measurement must be considered in experimental designs.


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