Dispersion of repolarization. A basic electrophysiological mechanism behind malignant arrhythmias

1997 ◽  
Vol 18 (8) ◽  
pp. 1200-1202 ◽  
Author(s):  
J. P. AMLIE
Keyword(s):  
Dispersion Of Repolarization ◽  
Electrophysiological Mechanism ◽  
Malignant Arrhythmias

scholarly journals Gender differences in ECG markers of increased risk for malignant arrhythmias, peripheral blood parameters, and adverse outcomes in patients with COVID-19 pneumonia

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Samet Kasim ◽  
Mohammed Alareedh ◽  
Hussein Nafakhi ◽  
Karrar Al-Buthabhak ◽  
Ahmed Nafakhi
Keyword(s):  
Gender Differences ◽  
Lung Injury ◽  
Peripheral Blood ◽  
Blood Parameters ◽  
Adverse Outcomes ◽  
Qtc Interval ◽  
Hospital Outcome ◽  
Dispersion Of Repolarization ◽  
Increased Risk ◽  
Malignant Arrhythmias

Background: The available data on gender differences in a) markers of cardiac involvement, b) peripheral blood parameters, and c) clinical adverse outcomes related to COVID-19 pneumonia severity are limited in the literature.: Objectives: To investigate gender differences in ECG markers of increased risk for malignant arrhythmias. This includes T from peak to end (Tp-e) interval, corrected QT (QTc), transmural dispersion of repolarization (TDR)(Tp-e/QTc), and index of cardiac electrophysiological balance (iCEB)(QTc/QRS), peripheral blood parameters, and in-hospital adverse outcomes in patients with COVID-19 pneumonia. Methods: A cross sectional study enrolled patients with COVID-19 pneumonia admitted to hospital from August 20th, to September 30th, 2020. Results: A total of 197 patients were included. Ninety-six (47%) were men and 101 women. There were no significant gender related differences concerning comorbidities. Men had higher QRS values, Tp-e interval and TDR, and lower values of iCEB. No significant gender differences were observed in the distribution of QTc interval. Men stayed longer in the hospital and had more extensive lung injury than women. In men, prolonged QTc interval, low lymphocytes %, high platelet distribution width (PDW), and low hemoglobin (Hb) were the main predictors of adverse in-hospital outcome, while prolonged QTc interval, high PDW, and low platelet count were the main predictors of adverse in-hospital outcome for women. Conclusions: Men had higher TDR values, lower iCEB, stayed longer in the hospital, and had more extensive lung injury than women, suggesting that, despite that there was no significant difference in mortality incidents between the two genders, the difference in surrogate markers may indicate that men are at a higher risk for adverse outcomes.

scholarly journals Changes in left ventricular electromechanical relations during targeted hypothermia

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Kristin Wisløff-Aase ◽  
Viesturs Kerans ◽  
Kristina Haugaa ◽  
Per Steinar Halvorsen ◽  
Helge Skulstad ◽  
...  
Keyword(s):  
Heart Rate ◽  
Qt Interval ◽  
Clinical Importance ◽  
Left Ventricular ◽  
Peak Strain ◽  
Time To Peak ◽  
Mechanical Dispersion ◽  
Dispersion Of Repolarization ◽  
Aortic Valve Closure ◽  
Prolonged Qt Interval

Abstract Background Targeted hypothermia, as used after cardiac arrest, increases electrical and mechanical systolic duration. Differences in duration of electrical and mechanical systole are correlated to ventricular arrhythmias. The electromechanical window (EMW) becomes negative when the electrical systole outlasts the mechanical systole. Prolonged electrical systole corresponds to prolonged QT interval, and is associated with increased dispersion of repolarization and mechanical dispersion. These three factors predispose for arrhythmias. The electromechanical relations during targeted hypothermia are unknown. We wanted to explore the electromechanical relations during hypothermia at 33 °C. We hypothesized that targeted hypothermia would increase electrical and mechanical systolic duration without more profound EMW negativity, nor an increase in dispersion of repolarization and mechanical dispersion. Methods In a porcine model (n = 14), we registered electrocardiogram (ECG) and echocardiographic recordings during 38 °C and 33 °C, at spontaneous and atrial paced heart rate 100 beats/min. EMW was calculated by subtracting electrical systole; QT interval, from the corresponding mechanical systole; QRS onset to aortic valve closure. Dispersion of repolarization was measured as time from peak to end of the ECG T wave. Mechanical dispersion was calculated by strain echocardiography as standard deviation of time to peak strain. Results Electrical systole increased during hypothermia at spontaneous heart rate (p < 0.001) and heart rate 100 beats/min (p = 0.005). Mechanical systolic duration was prolonged and outlasted electrical systole independently of heart rate (p < 0.001). EMW changed from negative to positive value (− 20 ± 19 to 27 ± 34 ms, p = 0.001). The positivity was even more pronounced at heart rate 100 beats/min (− 25 ± 26 to 41 ± 18 ms, p < 0.001). Dispersion of repolarization decreased (p = 0.027 and p = 0.003), while mechanical dispersion did not differ (p = 0.078 and p = 0.297). Conclusion Targeted hypothermia increased electrical and mechanical systolic duration, the electromechanical window became positive, dispersion of repolarization was slightly reduced and mechanical dispersion was unchanged. These alterations may have clinical importance. Further clinical studies are required to clarify whether corresponding electromechanical alterations are accommodating in humans.

scholarly journals Fractional diffusion models of cardiac electrical propagation: role of structural heterogeneity in dispersion of repolarization

2014 ◽  
Vol 11 (97) ◽  
pp. 20140352 ◽  
Author(s):  
Alfonso Bueno-Orovio ◽  
David Kay ◽  
Vicente Grau ◽  
Blanca Rodriguez ◽  
Kevin Burrage
Keyword(s):  
Structural Heterogeneity ◽  
Biological Tissues ◽  
Tissue Level ◽  
Fractional Diffusion ◽  
Diffusion Models ◽  
Excitable Media ◽  
Research Fields ◽  
Dispersion Of Repolarization ◽  
Electrical Propagation

Impulse propagation in biological tissues is known to be modulated by structural heterogeneity. In cardiac muscle, improved understanding on how this heterogeneity influences electrical spread is key to advancing our interpretation of dispersion of repolarization. We propose fractional diffusion models as a novel mathematical description of structurally heterogeneous excitable media, as a means of representing the modulation of the total electric field by the secondary electrical sources associated with tissue inhomogeneities. Our results, analysed against in vivo human recordings and experimental data of different animal species, indicate that structural heterogeneity underlies relevant characteristics of cardiac electrical propagation at tissue level. These include conduction effects on action potential (AP) morphology, the shortening of AP duration along the activation pathway and the progressive modulation by premature beats of spatial patterns of dispersion of repolarization. The proposed approach may also have important implications in other research fields involving excitable complex media.

scholarly journals ECG markers of malignant arrhythmias and in‐hospital outcome of COVID‐19 pneumonia

2021 ◽  
Author(s):  
Foaad Shaghee ◽  
Hussein Nafakhi ◽  
Mohammed Alareedh ◽  
Ahmed Nafakhi ◽  
Karrar Al‐Buthabhak
Keyword(s):  
Hospital Outcome ◽  
Malignant Arrhythmias

Electrophysiological mechanism of the antiarrhythmic action of naloxone

1988 ◽  
Vol 20 ◽  
pp. 125 ◽  
Author(s):  
P. de Bonfioli Cavalcabo ◽  
I. Masini ◽  
P. Bizzarri ◽  
E. Cerbai ◽  
A. Mugelli
Keyword(s):  
Antiarrhythmic Action ◽  
Electrophysiological Mechanism

scholarly journals BNP as a promising marker in prediction of malignant arrhythmias in pts with LV systolic dysfunction after an acute MI

2018 ◽  
Vol 7 (3) ◽  
pp. 306-309
Author(s):  
Ahmed Yassin ◽  
MohamedAbo Hamila ◽  
Ahmed Battah ◽  
Amal Rizk ◽  
SheriefMokhtar
Keyword(s):  
Systolic Dysfunction ◽  
Acute Mi ◽  
Malignant Arrhythmias

scholarly journals Sudden Cause of Cardiac Death—Be Aware of Me: A Case Report and Short Review on Brugada Syndrome

2010 ◽  
Vol 2010 ◽  
pp. 1-3 ◽  
Author(s):  
Jagadeesh K. Kalavakunta ◽  
Vishwaroop Bantu ◽  
Hemasri Tokala ◽  
Mihas Kodenchery
Keyword(s):  
Brugada Syndrome ◽  
Past History ◽  
Short Review ◽  
Case Presentation ◽  
St Segment Elevation ◽  
First Case ◽  
St Segment ◽  
The Right ◽  
Malignant Arrhythmias

Introduction. Brugada syndrome accounts for about 4% of sudden cardiac deaths (SCD). It is characterized by an ST-segment elevation in the right precordial electrocardiogram (EKG) leads.Case Presentation. We describe a 39-year-old healthy Caucasian man who was admitted to the intensive care unit after being cardioverted from ventricular fibrillation (VF) arrest. His past history was significant for an episode of syncope one month prior to this presentation for which he was admitted to an outlying hospital. EKG during that admission showed ST elevations in V1 and V2 leads, a pattern similar to Type 1 Brugada. A diagnosis of Brugada syndrome was missed and the patient had a cardiac arrest a month later. We discuss a short review of Brugada syndrome and emphasize the need to look for it in patients presenting with SCD and malignant arrhythmias.Conclusion. Physicians should always consider Brugada syndrome in the differential diagnosis of ST-segment elevation in anterior precordial leads of EKG and associated VT/VF. Although more than 17 years have passed since the first case was reported, increased awareness of this syndrome is needed to identify patients with EKG changes and treat them accordingly to prevent incidence of (SCD) and its deleterious complications.

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