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Ventricular Arrhythmias in Heart Failure
Published in Andreas P. Kalogeropoulos, Hal A. Skopicki, Javed Butler, Heart Failure, 2023
Antonis S. Manolis, Antonis A. Manolis, Theodora A. Manolis
Based on prior reviews, 60–90% of patients with HF have ventricular arrhythmias in the form of PVCs.4 Factors that may point to worse prognosis in patients with PVCs may comprise the type of underlying structural heart disease, a high PVC burden (>2000 PVCs/24 h), complex PVCs (couplets, triplets, and NSVT), increased number of morphologies, increasing number of PVCs with exercise, non-outflow tract PVC, short coupling interval of PVCs (“R-on-T”), and PVCs with broader QRS complexes.5,6
The patient with acute cardiovascular problems
Published in Peate Ian, Dutton Helen, Acute Nursing Care, 2020
QRS complex: the largest part of the ECG complex is the QRS complex. This represents the wave of depolarisation as it spreads across the ventricular myocardium. Providing that the bundle branches are both conducting normally, the QRS should be narrow in configuration, with no visible notches present. The QRS may be upright (positive) or downward (negative), depending on the surface of the heart that is facing the ECG lead. The QRS complex is rapid, at less than 0.12 seconds (seen as 3 small squares on ECG paper).
Bioelectric and Biomagnetic Signal Analysis
Published in Arvind Kumar Bansal, Javed Iqbal Khan, S. Kaisar Alam, Introduction to Computational Health Informatics, 2019
Arvind Kumar Bansal, Javed Iqbal Khan, S. Kaisar Alam
In a healthy person, the PR-interval (the interval between P-wave and R-wave) is between 0.12 seconds (3.0 mm) and 0.20 seconds (5.0 mm). The amplitude of a regular P-wave is around 0.25 mV (∼2.5 mm). The QRS-complex's duration is around 0.10 seconds (∼2.5 mm), and the amplitude varies for different people. It depends upon the size of the chamber and the amount of muscles in the ventricles.
Paroxysmal 2/1 atrioventricular block: do not pace! Why and what is the mechanism?
Published in Acta Cardiologica, 2023
Nader Wansa, Steven Vercauteren, Luc De Roy
In our case, the sudden and unexpected appearance of a 2-to-1 atrioventricular block in the absence of demonstrable conduction abnormalities, in conjunction with the presence of a junctional ectopic activity led to the suspicion of a pseudo atrioventricular block. An EP study validated the junctional origin of these beats with an absence of any preceding P wave and a clear His deflection before each QRS. The mechanism of the anterograde block could be documented: conduction towards the ventricles blocked when the coupling interval of the ectopic beats became slightly shorter (Figure 3), leading to the disappearance of the QRS complexes seen on the surface ECG. The absence of retrograde conduction to the atria and the temporary refractoriness of the AV conduction system explains the inability of the subsequent normal sinus P wave to conduct towards the ventricles. The ECG tracings do not show any ectopic activity at that moment and mimic a 2-to-1 atrioventricular block.
May myocardial work predict the risk of cardiomyopathy in patients with premature ventricular complex?
Published in Acta Cardiologica, 2023
Nursen Keles, Erkan Kahraman, Kemal Emrecan Parsova, Murat Bastopcu, Mesut Karatas, Nizamettin Selcuk Yelgec
The QRS complex duration of PVC’s was discovered to be a significant predictor of PVC-induced cardiomyopathy. Increased QRS complex duration raised the incidence of PVC-induced cardiomyopathy from %3 to %12. A prolongation of QRS complex duration (>140 ms) in PVCs originating from the free wall of the ventricles and outflow tracts independently predicted LVEF dysfunction [3,22,23]. Schrub et al. demonstrated that LV dyssynchrony was associated with reduced LVEF, lower GWE, and higher GWW [24]. It has been shown that in cardiac resynchronisation therapy (CRT) patients, GWW decreases and GWI increases due to the disappearance of dyssynchrony [8]. In addition, we observed in our study that the length of the PVC QRS was inversely connected with GCW, GWI, and GWE values, but was directly correlated with GWW in patients with PVC.
Establishment of a new arrhythmia model in SD rats induced by isoproterenol
Published in Acta Cardiologica, 2023
Zijing Guo, Nan Zhang, Kexin Ma, Qinghua Lei, Guoping Ma, Baozhu Ding, Yi Zhong, Wenjie Liang, Nan Li
ECGs of the rats before and after induction were continuously recorded, and the ventricular premature beat (VP), ventricular tachycardia (VT) and ventricular fibrillation (VF) were determined according to the Lambeth Conventions standard. The early appearance of QRS complexes was used to identify VP; nonsustained VT (NSVT) indicated that the number of consecutive occurrences of VP was less than 15; sustained ventricular tachycardia (SVT) meant that the number of consecutive occurrences of VP was at least 15; the atrioventricular block (AVB) was found between the atria and ventricles, and the impulse was slowed or blocked. The arrhythmia score (severity) was divided into 5 under the basic rating system as follows: 0 = no arrhythmia, 1 = single VP, 2 = double VP, 3 = three VP or NSVT, 4 = SVT or AVB, and 5 = death [14–16].