Search results for "Arrhythmia"

A hybrid stimulation strategy for suppression of spiral waves in cardiac tissue

2011

International audience; Atrial fibrillation (AF) is the most common cardiac arrhythmia whose mechanisms are thought to be mainly due to the self perpetuation of spiral waves (SW). To date, available treatment strategies (antiarrhythmic drugs, radiofrequency ablation of the substrate, electrical cardioversion) to restore and to maintain a normal sinus rhythm have limitations and are associated with AF recurrences. The aim of this study was to assess a way of suppressing SW by applying multifocal electrical stimulations in a simulated cardiac tissue using a 2D FitzHugh-Nagumo model specially convenient for AF investigations. We identified stimulation parameters for successful termination of S…

Sodium-hydrogen exchange inhibition: novel strategy to prevent myocardial injury following ischemia and reperfusion.

1999

Activation of Na+/H+ exchange and subsequent calcium overload in cardiac myocytes appear to play an important role in myocardial tissue injury following ischemia and reperfusion. Results of several in vitro studies in isolated myocytes and heart preparations and in vivo studies in pigs and rats have suggested that inhibition of Na+/H+ exchange is an effective means to prevent lethal reperfusion injury, arrhythmia, and improve myocardial contractile dysfunction. In patients with acute myocardial infarction (MI), any preventive agent is administered immediately before or shortly after reperfusion, rather than before the occurrence of coronary occlusion. The direct interventional approach to t…

Critical role of cardiac magnetic resonance in the diagnosis of left-dominant arrhythmogenic cardiomyopathy: A paradigmatic case in a recreational mi…

2021

Stroke and cardiac arrhythmias.

2001

Stroke is frequently followed by electrocardiographic (ECG) changes. The aim of the present study was to evaluate the global incidence of these changes after ischemic or hemorrhagic strokes, but it focused on cardiac arrhythmias. In ischemic strokes, these were correlated with the side of the lesion(s). The study was retrospective, and 450 patients (out of 971 examined) were entered in the study based on the following inclusion criteria: (1) "completed" stroke (352 ischemic and 98 hemorrhagic), (2) ECG on admission, and (3) at least 1 previous ECG. We also examined 71 patients with carotid or vertebro-basilar transient ischemic attacks (TIA). As controls, 71 patients suffering from nonvascu…

Information domain approach to the investigation of cardio-vascular, cardio-pulmonary, and vasculo-pulmonary causal couplings

2011

The physiological mechanisms related to cardio-vascular (CV), cardio-pulmonary (CP), and vasculo-pulmonary (VP) regulation may be probed through multivariate time series analysis tools. This study applied an information domain approach for the evaluation of non-linear causality to the beat-to-beat variability series of heart period (t), systolic arterial pressure (s), and respiration (r) measured during tilt testing and paced breathing (PB) protocols. The approach quantifies the causal coupling from the series i to the series j (C(ij)) as the amount of information flowing from i to j. A measure of directionality is also obtained as the difference between two reciprocal causal couplings (D(i…

Arrhythmieprofil und Herzfrequenz bei Hyperthyreose

2008

Arrhythmia profiles and heart rates, obtained by 24-hour ECG monitoring, were analysed in 48 patients with hyperthyroidism before (T3 level: 331 +/- 108 ng/100 ml, heart rate: 95 +/- 13/min), during (T3 level: 202 +/- 98 ng/100 ml, heart rate: 85 +/- 11/min) and after (T3 level: 149 +/- 41 ng/100 ml, heart rate: 79 +/- 9/min) antithyroid treatment. 50 persons in whom organic heart disease has been excluded by invasive and noninvasive tests served as controls. Only 6% of patients had repetitive ventricular arrhythmias (Lown group IV) before treatment (controls: 4%; P greater than 0.05). Supraventricular extrasystoles were common both before and after treatment (P less than 0.001), especially…

Intracardiac Cardioversion for Ablation of the Atrioventricular Conduction System in Patients with Drug Resistant Atrial Flutter

1983

The technique of intracardiac cardioversion for the ablation of the atrioventricular conduction system was used in three male patients (65, 53 and 57 years of age) with atrial flutter unresponsive to medical management. In the first patient a DC current of 80 J was applied while the other patients required 300 and 400 J respectively. In the first patient a transient third degree AVblock was induced enabling the ventricular rate to be easily controlled with drugs. This patient died 5 months later of resistant congestive heart failure. Autopsy revealed no gross evidence of myocardial damage in the tricuspid valve area or in the interventricular septum. In the other two patients a permanent th…

Multiscale Information Decomposition Dissects Control Mechanisms of Heart Rate Variability at Rest and During Physiological Stress.

2019

Heart rate variability (HRV

Influence of the terminal complement-complex on reperfusion injury, no-reflow and arrhythmias: a comparison between C6-competent and C6-deficient rab…

1996

Objective: The complement system has been suggested to play a role in reperfusion injury which may result from an enhanced destruction of myocardial tissue or from an impairment of reflow. We investigated the influence of the C5b-9 complement complex on infarct size, reflow and arrhythmogenesis. Methods: Twenty-eight C6-competent rabbits and 18 rabbits with congenital C6 deficiency were subjected to either 30 min or 2 h of coronary artery occlusion followed by reperfusion. C6 deficiency was confirmed by the complement titration test and immunohistology. The triphenyl tetrazolium chloride method was used to delineate infarct size. Reflow into infarcted areas was evaluated histologically afte…

Prospective appraisal of the prevalence of primary aldosteronism in hypertensive patients presenting with atrial flutter or fibrillation (PAPPHY Stud…

2013

Primary aldosteronism (PA) is the most common endocrine form of hypertension and may carry an increased risk of atrial flutter or fibrillation (AFF). The primary goal of this multicentre cohort study is thus to prospectively establish the prevalence of PA in consecutive hypertensive patients referred for lone (non-valvular), paroxysmal or permanent AFF. Secondary objectives are to determine: (1) the predictors of AFF in patients with PA; (2) the rate of AFF recurrence at follow-up after specific treatment in the patients with PA; (3) the effect of AFF that can increase atrial natriuretic peptide via the atrial stretch and thereby blunt aldosterone secretion, on the aldosterone-to-renin rati…