antiarrhytmics

Lidocaine is a class I antiarrhytmic drug that blocks Na(+) channels and exists in both neutral and charged forms at a physiological pH. In this work, a mathematical model of pH and the frequency-modulated effects of lidocaine has been developed and incorporated into the Luo-Rudy model of the ventricular action potential. We studied the effects of lidocaine on Na(+) current, maximum upstroke velocity, and conduction velocity and demonstrated that a decrease of these parameters was dependent on pH, frequency, and concentration...

Syncope is a common disorder which may recur and impair the survival and the quality of life of the patients. The objective of the investigation of syncope is to diagnose the cardiac etiology, as mortality rate is high. Implantable loop recorder or insertable cardiac monitor (ICM) is a useful tool to establish a correlation between syncope and heart rhythm. About half of implanted patients complain of a new syncope and about 50% of these patients had cardiac rhythm disturbances on ICM. The most frequent is a sinus bradycardia or sinus arrest, but these results depend on the age of patients, resting electrocardiography (ECG) abnormalities and structural cardiac disease...

Statins are well-established and effective drugs in the treatment of hyperlipidemias and coronary heart disease. However the effects of statins extend beyond their lipid-lowering actions, due to their capacity to inhibit prenylation of some intracellular regulatory proteins. Recent studies have shown that statins could modulate inflammantory response, improve endothelial function, exert antiarrhytmic properties, have beneficial effects on renal function and bone tissue. Statins may exert effect in the treament and prevention of dementia and some autoimmune disorders...

Cardiac arrhythmia are one of the major causes of cardiovascular and general morbi-mortality. This is the reason for a very quick and well-guided approach. One of the most used drug for this purpose is amiodarone, due to its high therapeutic potency and despite its risk for adverse effects. The most wellknown adverse effect seems to be the thyroid toxicity but, in reality, the most common ones involve the gastrointestinal and respiratory tract, with lung toxicity as a leader (incidence 6-7%). The two clinical cases which make the central point of this work are clear examples for being interested about amiodarone presence when a pulmonary fibrosis is present...

BACKGROUND: Amiodarone is a very effective antiarrhytmic drug. However its use may be accompanied by side effects. Hyperglobulinemia was not described in association with amiodarone treatment. MATERIALS AND METHODS: Fifteen patients, who developed hyperglobulinemia while on amiodarone therapy, were identified among the patients hospitalized in our hospital. Serum globulin concentration was measured prior to, during and after amiodarone therapy. RESULTS: In 11 of the 15 patients with amiodarone-associated hyperglobulinemia, amiodarone treatment had to be stopped because of amiodarone-induced complications, nine of them had pneumonitis...

Amiodarone is an antiarrhytmic drug and it is used to treat supraventricular or ventricular rhythm disturbances. Nevertheless it is not free of side effects. Amiodarone-induced pulmonary toxicity is one of them and is relatively rare (5 to 10% of cases) and can be fatal. There are several cumulative factors that may enhance susceptibility to pulmonary toxicity, such as advanced age and pre-existing pulmonary dysfunction. We present a case study of amiodarone-induced toxicity (pulmonary fibrosis) in an 81-year-old man...

A female patient was admitted to our Department for total thyroidectomy in amiodarone-induced thyrotoxicosis. The drug was prescribed for ventricular arrhythmia and atrial paroxysmal fibrillation in dilated cardiomyopathy due to chronic aortic regurgitation with left ventricular dysfunction (ejection fraction 35%; Class Functional NYHA III) and moderate-severe respiratory insufficiency. The cardiologist-anesthetist team has allowed to evaluate the surgical-cardiovascular-anesthesiologic risks and the balance between the improvement by the amiodarone administration for the arrhythmia, and the discontinuation of this treatment in order to prevent aggravation of the thyrotoxicosis...

Amiodaron is a widely used antiarrhytmic drug in a number of cardiac conditions. The most common side effects affect the thyroid gland (14-18% of treated patients) resulting in hypothyroidism or hyperthyroidism. We describe a complex case of amiodaron-induced thyrotoxicosis (AIT) and discuss the pathogenesis of the different subtypes (AIT I, II and mixed forms) and the diagnostic and therapeutic challenges in such patients.

Polyunsaturated fatty acids of n-3 family play an important role in the prevention of ischemic heart disease, as was shown in many epidemiological as well as intervention studies. These fatty acids are essential and human organism is fully dependent on their dietary intake from chloroplast of green plants and fat of aquatic animals. Cardioprotective action of these acids results from their complex effect (antiarrhytmic, antithrombotic, antiinflammatory, hypolipidemic etc.). These acids can, with the exception of glucose homeostasis, favourably influence individual components of the metabolic syndrome...

Stobadine, (-)- cis-2,8-dimethyl-2 ,3,4,4a,5,9b-hexahydro-1H-pyrido-[4,3b]-indole, is a pyridoindole derivative with antioxidant, antiarrhytmic, neuroprotective, local anesthetic, alpha-adrenolytic, antihistaminic, myorelaxant and other pharmacodynamic effects. The antioxidant properties were tested in a model system of egg yolk phosphatidylcholine (EYPC) multilamellar liposomes. The lipoperoxidation was induced by adding Cu2+ ions and tert-butylhydroperoxide. The course of EYPC peroxidation was monitored spectrophotometrically for conjugated diene formation...

The experiments with anesthetized rats showed that drugs belonging to various subclasses of class I antiarrhytmic agents (novocainamide, IA; lidocaine, IB; ethacizine, IC) produce a pronounced antifibrillatory and antiarrhythmic action under the conditions of a 7-min occlusion followed by reperfusion of the anterior descending branch of the left coronary artery. In the arrhythmia model with beta-adrenoreceptors stimulated by isoproterenol, novocainamide (IA) and lidocaine (IB) retained their efficacy, in contrast to ethacizine (IC)...

Implantation of transvenous implantable cardioverter-defibrillators (ICDs) utilizing a non-thoracotomy approach has become routine therapy for survivors of life-threatening tachyarrhythmias. In the Antiarrhythmics versus Implantable Defibrillator (AVID) Trial, we sought to identify and prospectively characterize the frequency of lead and ICD-related complications. Between June 1, 1993, and April 7, 1997, 539 patients received non-thoracotomy ICDs. A total of 62 first complications occurred. The subclavian route of insertion resulted in more complications than the cephalic vein route, 46 of 339 (14%) versus 6 of 135 (4%), p =...

The problem of drug interactions is very important in pharmacotherapy. The interactions of some drugs (antihistamines, macrolides, fluoroquinolones, cisapride) with other can induce ventricular arrhythmias. A lot of non-antiarrhytmic drugs can prolong the QT interval, induce torsade de pointes and cardiotoxicity.

Amiodarone is an effective antiarrhytmic drug and it is used to treat supraventricular or ventricular rhythm disturbances. Nevertheless it is not free from side effects. Acute amiodarone-induced pulmonary toxicity is one of them. We referred a 55-year-old man who started on amiodarone after a mitral valva replacement. Afterwards he had acute respiratory failure and diffuse ill-defined opacities. The diagnosis was confirmed by detection of lots of foamy macrophages in the bronchoalveolar lavage fluid. Relief of symptoms and arterial blood gases improvement was achieved when he started on corticosteroids and amiodarone treatment was stopped...

Carvedilol is a cardiovascular drug of multifaceted therapeutic potential, with beta-blocker and vasodilatative activity. These actions confer to the above mentioned betablocker some beneficial properties on several processes involving cardiovascular system. Carvedilol provides haemodynamic, antiischemic, antiproliferative and antiarrhytmic benefits, for its antioxidant neurohumoral and electrophysiological effects. All these actions provide the basis for usefulness of the drug in the treatment of hypertension, coronary heart disease, and congestive heart failure...

We report results on the functional analysis of Saccharomyces cerevisiae ORF YNL065w, predicted to code for a protein belonging to the poorly characterized major facilitator superfamily (MFS) of transporters that are involved in multidrug resistance (MDR). YNL065w is important for a moderate increase of yeast tolerance to ketoconazole and to the cationic dye crystal violet; it protects the cell against short-chain monocarboxylic acids (C(2)-C(6)), but not against highly liposoluble acids such as octanoic acid or the phenoxyacetic-acid herbicides 2,4-D and MCPA; it is also a determinant of resistance to the antiarrhytmic and antimalarial drug quinidine...

K+ currents activated by hypotonic cell swelling have been studied in Ehrlich ascites tumour cells by the whole-cell recording mode of the patch-clamp technique. K+ together with Cl- currents developed in the absence of added intracellular Ca2+ and with strong buffering of internal Ca2+ in experiments conducted at 37 degrees C. Manipulation of the extracellular medium with other cations suggests a selectivity sequence of K+ > Rb+ > NH4+ > or = Na+ approximately equals Li+ approximately equals Cs+. The current-voltage relationship of the volume-sensitive K+ current was well fitted with the Goldman-Hodgkin-Katz current equation between -130 and 20 mV at both physiological and high K+ extracellular solutions...

Atrial fibrillation (AF) is a prevalent arrhythmia associated with significant morbidity and mortality. Electrical cardioversion of AF is a potentially definitive treatment, but as little as 67% of patients may be successfully cardioverted and, after normal sinus rhythm (NSR) is achieved, AF often recurs. Class IA, IC, and III antiarrhytmic agents are used for both facilitation of electrical cardioversion and subsequent maintenance of NSR. The mechanisms of these agents may be related to suppressing automaticity, prolonging the wavelength of reentrant wavelets, and preventing electrical remodeling...

Typical atrial flutter is a macroreentrant arrhythmia of the right atrium. The isthmus area between the tricuspid annulus, the inferior vena cava, and the ostium of the coronary sinus is a critical zone of the reentry circle. Atrial flutter has been treated with class I and III antiarrhytmic drugs to maintain sinus rhythm, with moderate success. Catheter ablation has been highly successful in treating atrial flutter. A contiguous line of bidirectional electrical block is created in the isthmus area between the tricuspid annulus and the inferior vena cava by application of radiofrequency energy...

UNLABELLED: The optimal therapeutic procedure for prevention of sudden cardiac death (SCD) after myocardial infarction involves identification of the patients with a high risk of malignant ventricular arrhythmias using non-invasive risk markers, invasive electrophysiological evaluation of high risk patients, selection of treatment (ICD, RFTA, antiarrhythmics) and evaluation of the effectiveness of treatment. The objective of this work is retrospective evaluation of the incidence of risk markers of sudden cardiac death and the importance of programmed ventricular stimulation for the prognosis of patients with malignant ventricular arrhythmias after myocardial infarction...