Humans ; Death, Sudden, Cardiac/prevention & control* ; Arrhythmias, Cardiac/therapy*

Arrhythmias, Cardiac ; etiology ; prevention & control ; Cardiac Pacing, Artificial ; adverse effects ; methods ; Humans

The use of an implantable cardioverter-defibrillator (ICD) is an effective treatment strategy for patients with aborted sudden cardiac death (SCD) and ventricular tachyarrhythmias. Primary prevention of SCD is a strategy involving the use of ICDs in patients who are at high risk for but who have not had any previous events of ventricular arrhythmias or cardiac arrest. Cardiac resynchronization therapy (CRT) improves symptoms of heart failure and left ventricular systolic function when used in patients with severe heart failure symptoms, reduced left ventricular ejection, and a wide QRS complex. CRT has also been proven to reduce the rate of hospitalization due to heart failure as well as the rate of death from any cause. In this review, we discuss the clinical trials and current clinical indications for the ICD and CRT.
Arrhythmias, Cardiac ; Cardiac Resynchronization Therapy* ; Death, Sudden, Cardiac ; Defibrillators, Implantable* ; Heart Arrest ; Heart Failure ; Hospitalization ; Humans ; Primary Prevention ; Tachycardia

Atrial fibrillation (AF) is the most common arrhythmia and is associated with increased cardiovascular morbidity and mortality. The anti-arrhythmic effect of statins on AF prevention appears to be highly significant in most clinical studies. However, some discrepancies do exist among different clinical studies. Different clinical settings and types of stains used may explain these differences between trials. The CHADS2 and CHA2DS2VASc scoring systems have been used for stroke risk stratification in AF patients. The recent study suggested that these scores can also be used to guide statin therapy for AF prevention. Patients with higher scores had a higher risk of developing AF and gained more benefits from statins therapy than those with lower scores. This review article focused on the ability of these scores to predict AF prevention by statins.
Arrhythmias, Cardiac ; Atrial Fibrillation* ; Coloring Agents ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors* ; Mortality ; Primary Prevention* ; Stroke

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

T wave alternans in ECG is an important prediction factor for a sudden death. It is crucial in clinic to quantify the amplitude of T wave alternans. However, T wave alternans are highly non-stationary, which makes accurate quantification very difficult. In this study, we proposed a new method to improve the amplitude quantification. We identified T wave alternans by principal component analysis (PCA) with statistical test, and processed the principal components with T wave alternans further by imposing sparse constraint. We evaluated and compared our method against other 4 popular solutions on an international benchmark database. The results including rank correlation coefficient and relative error indicate that this sparse principal component (SPC) based method is better than others.
Algorithms ; Arrhythmias, Cardiac ; diagnosis ; physiopathology ; Death, Sudden, Cardiac ; prevention & control ; Electrocardiography ; methods ; Humans ; Principal Component Analysis ; Signal Processing, Computer-Assisted

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

OBJECTIVE: In order to solve alarm fatigue, the algorithm optimization strategies were researched to reduce false and worthless alarms. METHODS: A four-lead arrhythmia analysis algorithm, a multiparameter fusion analysis algorithm, an intelligent threshold reminder, a refractory period delay technique were proposed and tested with collected 28 679 alarms in multi-center study. RESULTS: The sampling survey indicate that the 80.8% of arrhythmia false alarms were reduced by the four-lead analysis, the 55.9% of arrhythmia and pulse false alarms were reduced by the multi-parameter fusion analysis, the 28.0% and 29.8% of clinical worthless alarms were reduced by the intelligent threshold and refractory period delay techniques respectively. Finally, the total quantity of alarms decreased to 12 724. CONCLUSIONS To increase the dimensionality of parametric analysis and control the alarm limits and delay time are conducive to reduce alarm fatigue in intensive care units.
Alert Fatigue, Health Personnel/prevention & control* ; Arrhythmias, Cardiac/diagnosis* ; Clinical Alarms ; Humans ; Intensive Care Units ; Monitoring, Physiologic

Implantable cardioverter-defibrillators (ICDs) are an effective treatment strategy for patients with aborted sudden cardiac death (SCD) and ventricular tachyarrhythmias. rimary prevention of SCD is a strategy involving the use of ICDs in patients who are at high risk for, but have not had, any previous events of ventricular arrhythmias or cardiac arrest. Several randomized clinical trials have demonstrated the efficacy of ICDs in the primary prevention of SCD. Therefore, ICD implantation is recommended as a standard of care by the guidelines in patients who have ischemic or nonischemic cardiomyopathy and a low left ventricular ejection fraction. However, the rates of ICD implantation as a primary prevention in Korea is quite low compared to western countries. In this review, we will summarize the results and efficacy of ICDs in the clinical trials about primary prevention of SCD, the current treatment guidelines, and the reimbursement policy of Korean health insurance. We hope that this review will help broaden the recognition of importance of ICD implantation for the primary prevention of SCD.
Arrhythmias, Cardiac ; Cardiomyopathies ; Death, Sudden, Cardiac* ; Defibrillators, Implantable* ; Heart Arrest ; Hope ; Humans ; Insurance, Health ; Korea ; Primary Prevention* ; Standard of Care ; Stroke Volume ; Tachycardia

OBJECTIVEThe aim of the present study was to study the Effects of 11,12-epoxyeicosatrienoic acid (11,12-EET) on cardioplegia and reperfusion arrhythmias in the isolated perfused immature rabbit hearts.

METHODSIsolated immature rabbit hearts were randomly divided into two groups: group 1 (St. Thomas No.2 solution control n = 8) and group 2 (St. Thomas No.2 solution plus 11,12-EET n = 8). By means of Langendorff technique, these isolated rabbit hearts underwent (15 degrees C) hypothermia, 2 hours of ischemia after infusion of cardioplegic solution and 1 hour of reperfusion (37 degrees C). The mean times until the cessation of both electrical and mechanical activity were measured after infusion of cardioplegia. The same index until occurrence of both electrical and mechanical activity after reperfusion was observed too. We also measured the arrhythmias score, heart rate, coronary blood flow during the reperfusion and the myocardial water content, myocardial calcium content at the endpoint of the reperfusion period.

RESULTSThe times until electrical [(9.3 +/- 0.9) s vs (13.6 +/- 1.9) s, P < 0.01] and mechanical [(4.5 +/- 1.7) vs (7.3 +/- 2.1) s, P < 0.05] activity arrest were significantly shorter in the group 2 than those in the control group. 11,12-EET also provided significantly better myocardial water content [(84 +/- 4)% vs (90 +/- 5)%, P < 0.01], arrhythmia scores (2.03 +/- 0.83 vs 3.88 +/- 1.25, P < 0.01), coronary blood flow and myocardial calcium content [(3.22 +/- 0.33) micro mol/gram dry weight (gdw) vs (3.97 +/- 0.26) micro mol/gdw, P < 0.01] compared with control. There were no significant changes with heart rate and the mean times until occurrence of both electrical and mechanical activity after reperfusion.

CONCLUSIONSThese data suggest that 11,12-EET added to the cardioplegic solution of St. Thomas No.2 has better cardioplegia effects and lower incidence of reperfusion arrhythmias.

8,11,14-Eicosatrienoic Acid ; analogs & derivatives ; pharmacology ; Animals ; Arrhythmias, Cardiac ; prevention & control ; Heart Arrest, Induced ; Heart Rate ; drug effects ; In Vitro Techniques ; Myocardial Reperfusion Injury ; prevention & control ; Rabbits