Premature ventricular

Indeca.inide. Indecainide hydrochloride is a po active antiarrhythmic agent that received PDA approval in 1989, but it has not been marketed as of this writing. Chemically, it is 9-[3-(isopropylamino)propyl]fiuorine-9-carboxamide [74517-78-5]. The dmg has potent activity against premature ventricular complexes (PVCs) and ventricular tachycardias. Indecainide has no effect on sinus node function, atrial or ventricular effective refractory periods (32,33). 

Cardiac glycosides have a small ratio of toxic to therapeutic concentration. Possible adverse effects are nausea, vomiting, abdominal pain, diarrhoea, fatigue, headache, drowsiness, colour vision disturbances, sinus bradycardia, premature ventricular complexes, AV-block, bigeminy, atrial tachycardia with AV-Block, ventricular fibrillation. There are several mechanisms relevant for their toxic action (Table 2). 

Cardiac-changes in pulse rate or rhythm electrocardiographic changes, such as bradycardia, tachycardia, premature ventricular contractions, bigeminal (two beats followed by a pause), or trigeminal (three beats followed by a pause) pulse. Other arrhythmias (abnormal heart rhythms)also may be seen. 

The uses of the antiarrhythmic drug are given in the Summaiy Drug Table Antiarrhythmic Drug3. In general these drugp are used to prevent and treat cardiac arrhythmias, such as premature ventricular contractions (PVCs), ventricular tachycardia (VT), premature atrial contractions (PACs), paroxysmal atrial tachycardia (PAT), atrial fibrillation, and atrial flutter. Some of the antiarrhythmic dru are used for other... 

In humans cardiac arrhythmias have been recorded in 23% of patients when full-face peel was performed in less than 30 min. These arrhythmias included tachycardia, premature ventricular beats, bigeminy, atrial and ventricular tachycardia [19]. 

Premature Ventricular Depolarixation No PbTx Antibody Treatment (Lead VIO. 1 cm/mv. 25 mm/sec)... 

ECG normal sinus rhythm, PR 0.16 s, QRS 0.08 s, QTC 0.38 s, occasional polymorphic premature ventricular contractions, 3 mm ST-segment elevation anterior leads... 

Premature ventricular complexes (PVCs) are common ventricular rhythm disturbances that occur in patients with or without heart disease and may be elicited experimentally by abnormal automaticity, triggered activity, or reentrant mechanisms. 

Premature ventricular complexes, 5 88—89 Premature ventricular contractions, 5 108 Premetallized dyes, 9 215-216, 399-401 29 758-759... 

Exposure at 500,000 ppm induced narcosis in rhesus monkeys within 1 min (Shulman and Sadove 1967). Respiratory depression accompanied by multiple premature ventricular contractions occurred when concentrations exceeded 60%. Blood pressure was said to be increased, but the actual data were not reported. 

In an undated study, HCFC-141b was administered to male SpragueDawley rats at concentrations of 5,000, 10,000, or 20,000 ppm for 30 min (Eger, unpublished data). As exposure continued, bolus intravenous epinephrine, characterized as three times the dose that produced arrhythmias in the same rats anesthetized with halothane, was administered. The dose of epinephrine was defined as a maximum of 12 fig/kg. For this study, three or more premature ventricular contractions was considered an arrhythmic response (Table 4—5). Marked arrhythmias occurred at all concentrations. The author further compared the concentrations of halothane and HCFC-141b that produced arrhythmias with administration of various doses of exogenous epinephrine. The nominal chamber concentration for HCFC-141b did not differ from that of halothane. Furthermore, the arrhythmias were characterized as relatively mild and within acceptable limits for surgical anesthesia in humans. 

Lidocaine is the most widely used local anesthetic. Its excellent therapeutic activity is fast-acting and lasts sufficiently long to make it suitable for practically any clinical use. It stabilizes cell membranes, blocks sodium channels, facilitates the secretion of potassium ions out of the cell, and speeds up the repolarization process in the cell membrane. It is used for terminal infiltration, block, epidural, and spinal anesthesia during operational interventions in dentistry, otolaryngology, obstetrics, and gynecology. It is also used for premature ventricular extrasystole and tachycardia, especially in the acute phase of cardiac infarction. Synonyms for this drug are xylocaine, neflurane, and many others. 

Unlabeled uses In pediatric patients with cardiac arrest, less than 10% develop ventricular fibrillation, and others develop ventricular tachycardia the hemodynamically compromised child may develop ventricular couplets or frequent premature ventricular beats. In these cases, administer 1 mg/kg lidocaine by the IV, intraosseous, or endotracheal route. A second 1 mg/kg dose may be given in 10 to 15 minutes. Start a lidocaine infusion if the second dose is required a third bolus may be needed in 10 to 15 minutes to maintain therapeutic levels. 

Ventricuiar proarrhythmic effects in patients with atriai fibriiiation/fiutter Flecainide is not recommended for use in patients with chronic atrial fibrillation. Case reports of ventricular proarrhythmic effects in patients treated with flecainide for atrial fibrillation/flutter have included increased premature ventricular contractions (PVCs), ventricular tachycardia (VT), ventricular fibrillation (VF), and death. 

Pharmacology Bretylium tosylate inhibits norepinephrine release by depressing adrenergic nerve terminal excitability, inducing a chemical sympathectomy-like state. Bretylium blocks the release of norepinephrine in response to neuron stimulation. Peripheral adrenergic blockade causes orthostatic hypotension but has less effect on supine blood pressure. It has a positive inotropic effect on the myocardium. Pharmacokinetics Peak plasma concentration and peak hypotensive effects are seen within 1 hour of IM administration. However, suppression of premature ventricular beats is not maximal until 6 to 9 hours after dosing, when mean plasma concentration declines to less than 50% of peak level. Antifibrillatory effects occur within minutes of an IV injection. Suppression of ventricular tachycardia and other ventricular arrhythmias develops more slowly, usually 20 minutes to 2 hours after parenteral administration. 

Premature ventricular contractions (PVCs) During conversion or marked reduction in ventricular rate, benign complexes of unusual appearance (sometimes resembling PVCs) may occur after IV verapamil. 

Genera/-Arrhythmias changes in AV conduction ECG changes (most frequently with toxic doses) flushing heart block hot flushes hypertension hypotension orthostatic hypotension palpitations precipitation of CHF premature ventricular contractions stroke sudden death syncope tachycardia. 

Monitoring - Laboratory test monitoring for liver abnormalities is appropriate. Rapid IV administration Rapid IV administration of cimetidine has been followed by rare instances of cardiac arrhythmias and hypotension. Bradycardia, tachycardia, and premature ventricular beats in association with rapid administration of IV ranitidine may occur rarely, usually in patients predisposed to cardiac rhythm disturbances. 

PTCA percutaneous transluminal coronary angioplasty PTH parathyroid hormone PTT partial thromboplastin time PUD peptic ulcer disease pulm pulmonary PVC premature ventricular contraction... 

On the basis of two large randomized trials aimed at suppressing premature ventricular complexes after MI, so-called warning arrhythmias, it was discovered that many common antiarrhythmic medications actually increase the risk of mortality [20, 21]. Amiodarone also has been shown to have no definitive effect on mortality in patients after an MI, including in the recent SCD-HeFT trial [22-24]. In fact, of all antiarrhythmic medications, only beta blockers have been clearly shown to prevent SCD after MI [25], particularly among those with depressed LV function [11]. 

The indications for use of disopyramide are similar to those for quinidine, except that it is not approved for use in the prophylaxis of atrial flutter or atrial hbrUla-tion after DC conversion. The indications are as follows unifocal premature (ectopic) ventricular contractions, premature (ectopic) ventricular contractions of multifocal origin, paired premature ventricular contractions (couplets), and episodes of ventricular tachycardia. Persistent ventricular tachycardia is usually treated with DC conversion. 

Disopyramide Premature ventricular contractions Atrial arrhythmias, episodic ventricular tachycardia... 

Mexiletine Premature ventricular contractions Ventricular tachycardia... 

Procainamide Atrial tachycardia, ventricular tachycardia Premature ventricular contractions... 

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