- Time-dependent antiarrhythmic effects of flecainide on induced atrial fibrillation in horses. [Journal Article]
- JVJ Vet Intern Med 2018 Aug 22
- CONCLUSIONS: Flecainide is effective for cardioversion of short-term induced AF, but the effect decreases with AF duration. Controlling heart rate may minimize adverse effects caused by flecainide, but the drug should be used with great caution.
- A clustering-based method for single-channel fetal heart rate monitoring. [Journal Article]
- PlosPLoS One 2018; 13(6):e0199308
- Non-invasive fetal electrocardiography (ECG) is based on the acquisition of signals from abdominal surface electrodes. The composite abdominal signal consists of the maternal electrocardiogram along ...
Non-invasive fetal electrocardiography (ECG) is based on the acquisition of signals from abdominal surface electrodes. The composite abdominal signal consists of the maternal electrocardiogram along with the fetal electrocardiogram and other electrical interferences. These recordings allow for the acquisition of valuable and reliable information that helps ensure fetal well-being during pregnancy. This paper introduces a procedure for fetal heart rate extraction from a single-channel abdominal ECG signal. The procedure is composed of three main stages: a method based on wavelet for signal denoising, a new clustering-based methodology for detecting fetal QRS complexes, and a final stage to correct false positives and false negatives. The novelty of the procedure thus relies on using clustering techniques to classify singularities from the abdominal ECG into three types: maternal QRS complexes, fetal QRS complexes, and noise. The amplitude and time distance of all the local maxima followed by a local minimum were selected as features for the clustering classification. A wide set of real abdominal ECG recordings from two different databases, providing a large range of different characteristics, was used to illustrate the efficiency of the proposed method. The accuracy achieved shows that the proposed technique exhibits a competitve performance when compared to other recent works in the literature and a better performance over threshold-based techniques.
- Prognostic Value of Electrocardiography in Patients With Fulminant Myocarditis Supported by Percutaneous Venoarterial Extracorporeal Membrane Oxygenation - Analysis From the CHANGE PUMP Study. [Journal Article]
- CJCirc J 2018 Jul 25; 82(8):2089-2095
- CONCLUSIONS: In patients with FM, CAVB and VT/VF carried a higher risk of in-hospital death. Wide QRS also predicted a higher risk of in-hospital death in patients with SR.
- Occurrence of Potentially Lethal Arrhythmia due to Sudden Exposure of an Overt Accessory Pathway 8 Years After Catheter Ablation of a Concealed Accessory Pathway. [Case Reports]
- IHInt Heart J 2018 Jul 31; 59(4):857-861
- Although the efficacy of catheter ablation of the accessory pathway (AP) has been established, there are subgroups of APs with an intermittent conduction property, which is sometimes difficult to dia...
Although the efficacy of catheter ablation of the accessory pathway (AP) has been established, there are subgroups of APs with an intermittent conduction property, which is sometimes difficult to diagnose accurately. A 57-year-old man with a history of catheter ablation was referred to our clinic due to frequent faintness. He had undergone concealed AP ablation 8 years previously and bilateral circumferential pulmonary vein isolation (CPVI) 6 years previously. During regular electrocardiogram monitoring, it was suggested that irregular wide QRS tachycardia, which was considered to be atrial fibrillation with antegrade AP conduction, was the cause of the present symptoms. In the present electrophysiological study, we noticed a residual antegrade AP in the left lateral wall that was not observed during the previous session. We achieved abolition of overt accessory conduction, bilateral CPVI, and superior vena cava isolation with several radiofrequency applications without any recurrence. We also confirmed the absence of dormant conduction in the AP and the left atrium-PV connection with 20 mg adenosine triphosphate. This case demonstrated the possibility of sudden exposure of overt AP conduction late after catheter ablation of the concealed AP and the importance of confirming the absence of dormant conduction by means of adenosine triphosphate, which has the potential benefit of revealing latent AP conduction.
- The relation between coronary artery disease severity and fragmented QRS complex in patients with left bundle branch block. [Journal Article]
- EHEgypt Heart J 2017; 69(2):119-126
- CONCLUSIONS: Seeking for f-wQRS in patients with LBBB and suspected CAD is a simple, easy, available, method that may be helpful in noninvasive prediction of obstructive CAD.
- Genome-Wide Associations of Global Electrical Heterogeneity ECG Phenotype: The ARIC (Atherosclerosis Risk in Communities) Study and CHS (Cardiovascular Health Study). [Journal Article]
- JAJ Am Heart Assoc 2018 Apr 05; 7(8)
- CONCLUSIONS: We identified 10 genetic loci associated with ECG GEH. Replication of GEH GWAS findings in independent cohorts is warranted. Further studies of GEH-loci may uncover mechanisms of arrhythmogenic remodeling in response to cardiovascular risk factors.
- Iatrogenic Ventricular Fibrillation after Direct-Current Cardioversion of Preexcited Atrial Fibrillation Caused by Inadvertent T-Wave Synchronization. [Case Reports]
- THTex Heart Inst J 2018; 45(1):39-41
- Direct-current cardioversion is an important means of managing arrhythmias. During treatment, carefully synchronizing energy delivery to the QRS complex is necessary to avoid ventricular fibrillation...
Direct-current cardioversion is an important means of managing arrhythmias. During treatment, carefully synchronizing energy delivery to the QRS complex is necessary to avoid ventricular fibrillation caused by a shock during the vulnerable period of ventricular repolarization, that is, a shock on the T wave. The presence of an accessory pathway and ventricular preexcitation can lead to difficulty in distinguishing the QRS complex from the T wave because of bizarre, wide, irregular QRS complexes and prominent repolarization. We present the cases of 2 patients who had iatrogenic ventricular fibrillation from inappropriate T-wave synchronization during direct-current cardioversion of preexcited atrial fibrillation. Our experience shows that rapidly recognizing the iatrogenic cause of VF and immediate treatment with unsynchronized defibrillation can prevent adverse clinical outcomes.
- Case report: an unstable wide QRS complexes tachycardia after ablation of a poster-septal accessory pathway: What is the mechanism? [Case Reports]
- MMedicine (Baltimore) 2018; 97(11):e0120
- CONCLUSIONS: It was an atypical atrial-ventricular node reentrant tachycardia with right bundle branch block. Reasonable analysis based on electrophysiological electrophysiologic knowledge was the basis of successful diagnosis and treatment.
- Cardiac electrophysiological adaptations in the equine athlete-Restitution analysis of electrocardiographic features. [Journal Article]
- PlosPLoS One 2018; 13(3):e0194008
- Exercising horses uniquely accommodate 7-8-fold increases in heart rate (HR). The present experiments for the first time analysed the related adaptations in action potential (AP) restitution properti...
Exercising horses uniquely accommodate 7-8-fold increases in heart rate (HR). The present experiments for the first time analysed the related adaptations in action potential (AP) restitution properties recorded by in vivo telemetric electrocardiography from Thoroughbred horses. The horses were subjected to a period of acceleration from walk to canter. The QRS durations, and QT and TQ intervals yielded AP conduction velocities, AP durations (APDs) and diastolic intervals respectively. From these, indices of active, λ = QT/(QRS duration), and resting, λ0 = TQ/(QRS duration), AP wavelengths were calculated. Critical values of QT and TQ intervals, and of λ and λ0 at which plots of these respective pairs of functions showed unity slope, were obtained. These were reduced by 38.9±2.7% and 86.2±1.8%, and 34.1±3.3% and 85.9±1.2%, relative to their resting values respectively. The changes in λ were attributable to falls in QT interval rather than QRS duration. These findings both suggested large differences between the corresponding critical (129.1±10.8 or 117.4±5.6 bpm respectively) and baseline HRs (32.9±2.1 (n = 7) bpm). These restitution analyses thus separately identified concordant parameters whose adaptations ensure the wide range of HRs over which electrophysiological activation takes place in an absence of heart block or arrhythmias in equine hearts. Since the horse is amenable to this in vivo electrophysiological analysis and displays a unique wide range of heart rates, it could be a novel cardiac electrophysiology animal model for the study of sudden cardiac death in human athletes.
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- Echocardiography for the management of patients with biventricular pacing: Possible roles in cardiac resynchronization therapy implementation. [Review]
- HJHellenic J Cardiol 2018 Feb 13
- Cardiac resynchronization therapy (CRT) is an established therapeutic option for the subset of patients with heart failure (HF), reduced ejection fraction (EF), and dyssynchrony evidenced by electroc...
Cardiac resynchronization therapy (CRT) is an established therapeutic option for the subset of patients with heart failure (HF), reduced ejection fraction (EF), and dyssynchrony evidenced by electrocardiography. Benefit from CRT has been proven in many clinical trials, yet a sizeable proportion of these patients with wide QRS do not respond to this intervention, despite the updated practice guidelines. Several echocardiographic indices, targeting mechanical rather than electrical dyssynchrony, have been suggested to address this issue, but research so far has not succeeded in providing a single and simple measurement with adequate sensitivity and specificity for identification of responders. While there is still ongoing research in this field, echocardiography proves helpful in other aspects of CRT implementation, such as site selection for left ventricular (LV) lead pacing and optimization of pacing parameters during follow-up visits.