Arrhythmias, Cardiac ; complications ; genetics ; physiopathology ; Atrial Fibrillation ; complications ; genetics ; physiopathology ; Electrophysiology ; Humans

Arrhythmias, Cardiac/complications* ; Betacoronavirus ; COVID-19 ; Coronavirus Infections/complications* ; Humans ; Pandemics ; Pneumonia, Viral ; SARS-CoV-2

The aim of this study was to determine if the potassium aspartate and magnesium (PAM) prevent reperfusion-induced ventricular arrhythmias (RIVA) in ischemia-reperfusion (IR) rabbit heart. Thirty rabbits were randomly divided into control, ischemia and PAM groups. Arterially-perfused rabbit left ventricular preparations were made, and transmural ECG as well as action potentials from both endocardium and epicardium were simultaneously recorded in the whole process of all experiments. In control group rabbit ventricular wedge preparations were continuously perfused with Tyrode's solution, and in ischemia group and PAM groups the perfusion of Tyrode's solution was stopped for 30 min. Then the ischemia group was reperfused with Tyrode's solution and the PAM group with Tyrode's solution containing 2.42 mg/L PAM, respectively. ECG, QT interval, transmural repolarization dispersion (TDR) and action potentials from epicardium and endocardium were simultaneously recorded, and the RIVA of the wedge preparation was observed. Compared with control group, TDR and incidence of RIVA were significantly increased in ischemia group (P<0.05). The incidence of RIVA in control, ischemia and PAM group was 0/10, 9/10 and 1/10, respectively. Compared with ischemia group, TDR and incidence of RIVA were significantly reduced in PAM group (P<0.05). Potassium aspartate and magnesium significantly reduce TDR and prevent ventricular arrhythmia in ischemic rabbit heart.
Arrhythmias, Cardiac/etiology ; Arrhythmias, Cardiac/*prevention & control ; Myocardial Ischemia/*complications ; Myocardial Ischemia/physiopathology ; Myocardial Reperfusion Injury/*complications ; Potassium Magnesium Aspartate/*therapeutic use ; Random Allocation

Arrhythmias, Cardiac ; complications ; physiopathology ; Atrioventricular Block ; complications ; physiopathology ; Coronary Circulation ; Humans ; Male ; Middle Aged ; Syncope ; complications ; physiopathology

Aged ; Arrhythmias, Cardiac ; diagnosis ; physiopathology ; Coal Mining ; Electrocardiography ; Humans ; Male ; Middle Aged ; Pneumoconiosis ; complications ; physiopathology

OBJECTIVETo evaluate the effects of antiarrhythmic peptide (AAP10) on ventricular arrhythmias in rabbits with healed myocardial infarction (OMI).

METHODSThirty rabbits were randomly divided into three groups (n = 10 each): Sham group, left thoracotomy was performed without coronary ligation; OMI group and OMI + AAP10 group, the circumflex coronaries were ligated. Three months post operation, the electrophysiological and antiarrhythmic effects of AAP10 were assessed in the arterially perfused rabbit left ventricular wedge preparation. Sham and OMI group were perfused with Tyrode's solution and OMI + AAP10 group was perfused with Tyrode's solution + AAP10 (80 nmol/L). Transmembrane action potentials were recorded simultaneously from endocardium and epicardium together with a transmural ECG by use of 2 separate intracellular floating microelectrodes. The stimulus-response-interval (SRI) of the epicardium and the incidence of ventricular tachycardia (VT) were observed. Whole heart and left ventricular weights, the left ventricular thickness at infarct border zone were measured.

RESULTSWhole heart and left ventricular weights as well as the left ventricular thickness at the infarct border zone significantly increased post infarction. VT was induced in 8 out of 10 rabbits in OMI group and in 2 out of 10 rabbits in OMI + AAP10 group (P < 0.05). SRI was also significantly shortened in OMI + AAP10 group compared to OMI group [SRI-1: (20.59 +/- 0.79) ms vs. (28.71 +/- 0.55) ms; SRI-2: (30.42 +/- 0.74) ms vs. (38.67 +/- 0.49) ms, all P < 0.01]. However, the action potential morphology and duration were similar between OMI and OMI + AAP10 groups.

CONCLUSIONThe antiarrhythmic peptide (AAP10) can increase gap junctional intercellular conductance without affecting the action potential morphology and duration and decrease the incidence of inducible ventricular tachycardia.

Animals ; Arrhythmias, Cardiac ; etiology ; prevention & control ; Male ; Myocardial Infarction ; complications ; physiopathology ; Oligopeptides ; pharmacology ; Rabbits ; Random Allocation

BACKGROUND: We compared the mid-term results of the Cox maze IV procedure using argon-based cryoablation with a procedure using N2O-based cryoablation. METHODS: From May 2006 to June 2012, 138 patients (mean age, 58.2+/-11.0 years) underwent the Cox maze IV procedure. Eighty-five patients underwent the maze procedure using an N2O-based cryoprobe (group N), and 53 patients underwent the maze procedure using an argon-based cryoprobe (group A). Bipolar radiofrequency ablation was concomitantly used in 131 patients. The presence of atrial fibrillation immediately, 6 months, 1 year, and 2 years after surgery was compared. RESULTS: Early mortality occurred in 6 patients (4.3%). There were no differences in early mortality or postoperative complications between the two groups. Nineteen of 115 patients (16.5%) remained in atrial fibrillation at postoperative 12 months (14 of 80 patients (17.5%) in group N and 5 of 35 patients (14.3%) in group A, p=0.669). There were no differences in the number of patients who remained in atrial fibrillation at any of the time periods except in the immediate postoperative period. A multivariable analysis revealed that the energy source of cryoablation was not associated with the presence of atrial fibrillation at 1 year (p=0.862) and that a fine F wave (<0.1 mV) was the only risk factor predicting the presence of atrial fibrillation at 1 year (p<0.001, odds ratio=20.287). CONCLUSION: The Cox maze IV procedure using an argon-based cryoprobe was safe and effective compared with the maze procedure using an N2O-based cryoprobe in terms of operative outcomes and the restoration of sinus rhythm for up to 2 years after surgery.
Arrhythmias, Cardiac ; Atrial Fibrillation ; Catheter Ablation ; Cryosurgery* ; Humans ; Mortality ; Postoperative Complications ; Postoperative Period ; Risk Factors

Thiopental 6.7mg/kg and ketamine 0.9mg/kg was given for induction of general anesthesia and effect of the drugs on the bioparameters such as the time required for loss of consciousness, the occurance of arrhythmias, the amount of bronchial secretion, changes in blood pressure and pulse rate, and the postoperative complications were investigated in this study. The results were as follows. 1) The time required for loss of consciousness was 28 seconds in the ketamine group and 32 seconds in the thiopental group. 2) The occurance of arrhythmias was less in ketamine group than in thiopental group. 3) The degree of bronchial secretion was similar in both groups. 4) Ketamine did not increase the pulse rate greater anymore thiopental. 5) Blood pressure was significantly lowered after 10 minutes in the thiopental group but not changed in the ketamine group. 6) There was no hallucination or delirium in the two groups.
Anesthesia* ; Anesthesia, General ; Arrhythmias, Cardiac ; Blood Pressure ; Delirium ; Hallucinations ; Heart Rate ; Ketamine* ; Postoperative Complications ; Thiopental* ; Unconsciousness

The suppression of spiral waves and spatiotemporal chaos in cardiac tissue was studied based on cardiac model. We proposed two strategies of suppressing spiral wave and spatiotemporal chaos. One was to elevate the extracellular potassium ion concentration suddenly. This method can effectively suppress spiral waves and spatiotemporal chaos when the elevated extracellular potassium ion concentration reaches a critical value, especially when the spiral wave pinned to defects also can be suppressed. The other was to let the extracellular potassium ion concentration varies periodically while the amplitude of concentration was limited. We found that the method could effectively suppress spiral waves and spatiotemporal chaos when the related parameters were properly chosen. But it can not suppress the pinned spiral waves. And the control mechanism is discussed in this paper.
Action Potentials ; physiology ; Arrhythmias, Cardiac ; complications ; physiopathology ; Computer Simulation ; Heart ; physiology ; Humans ; Models, Cardiovascular ; Potassium ; metabolism

OBJECTIVETo study the ECG features in children with dilated cardiomyopathy (DCM), and related factors for the occurrence of arrhythmia secondary to DCM.

METHODSData from 68 children with DCM from January 1998 to March 2011 were studied. The children were classified into three groups: severe arrhythmia (n=42), non-severe arrhythmia (n=20) and non-arrhythmia (n=6). Left ventricular end diastolic diameter (LVED), left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were compared.

RESULTSAbnormal ECG results were found in all of the 68 children with DCM. Sinus tachycardia (91%) and ectopic pulsatile (86%) were common. LVED in the severe arrhythmia group (74±6 mm) was greater than that in the non-severe arrhythmia group (65±4 mm; P<0.05) and non-arrhythmia group (61±3 mm; P<0.05). LVED in the non-severe arrhythmia group was also greater than that in the non-arrhythmia group (P<0.05). LVEF and LVFS in the severe arrhythmia group were (30±11)% and (22±4)%, respectively, which were lower than those in the non-severe arrhythmia group［(37±12)% and (28±5)%, respectively］and non-arrhythmia group［(45±9)% and (34±7)%, respectively］(P<0.05). There were also significant differences in the LVEF and LVFS between the non-severe arrhythmia and non-arrhythmia groups (P<0.05).

CONCLUSIONSThe common abnormal ECG findings are sinus tachycardia and ectopic pulsatile in children with DCM. Arrhythmia is one of the main clinical manifestations of DCM. The occurrence of arrhythmia is associated with the left ventricular size and heart function.

Adolescent ; Arrhythmias, Cardiac ; etiology ; Cardiomyopathy, Dilated ; complications ; physiopathology ; Child ; Child, Preschool ; Electrocardiography ; Female ; Humans ; Infant ; Male