Adenosine arrhythmia with

Supraventricular bradycardia is treated by implantation of a pacemaker device or has been treated pharmacologically with atropine. Supraventricular paroxysmal tachycardia is treated with aj marine or praj marine. Supraventricular tachyarrhythmias or AV reentrant arrhythmia typically can be terminated using adenosine. 

The answer is e. (Hardman, pp 858-874.) Because verapamil, a Ca channel blocker, has a selective depressing action on AV nodal tissue, it is an ideal drug for both immediate and prophylactic therapy of supraventricular tachycardia (SVT). Nifedipine, another Ca channel blocker, has little effect on SAT Lidocaine and adenosine are parenteral drugs with short ha If-lives and, thus, are not suitable for prophylactic therapy. Procainamide is more suitable for ventricular arrhythmias and has the potential for serious adverse reactions with long-term use. 

Research on compounds that interact with adenosine A1 receptors has focused on agonists with structures based on adenosine itself as agents that will overcome responses due to inappropriate excitation such as tachycardia and some arrhythmias. Replacement of one of the hydrogen atoms on the exocyclic amine in adenosine by a tetrahydrofuryl group provides an effective A1 adenosine agonist. Preparation of this fragment as a single enantiomer starts with a modem version of the Curtius reaction. 

Supraventricular tachycardia is the major arrhythmia indication for verapamil. Adenosine or verapamil are preferred over older treatments (propranolol, digoxin, edrophonium, vasoconstrictor agents, and cardioversion) for termination. Verapamil can also reduce the ventricular rate in atrial fibrillation and flutter. It only rarely converts atrial flutter and fibrillation to sinus rhythm. Verapamil is occasionally useful in ventricular arrhythmias. However, intravenous verapamil in a patient with sustained ventricular tachycardia can cause hemodynamic collapse. 

ADENOSINE ANTIPSYCHOTICS Risk of ventricular arrhythmias, particularly torsades de pointes, with phenothiazines and pimozide. There is also a theoretical risk of Q-T prolongation with the atypical antipsychotics All of these drugs prolong the Q-T interval Avoid co-administration of phenothiazines, amisulpride, pimozide or sertindole with adenosine. Monitor the ECG closely when adenosine is co-administered with atypical antipsychotics... 

Rankin AC, Oldroyd KG, Chong E, Dow JW, Rae AP, Cobbe SM. Adenosine or adenosine triphosphate for supraventricular tachycardias Comparative double-blind randomized study in patients with spontaneous or inducible arrhythmias. Am Heart J 1990 119(2 Pt l) 316-23. 

B Because this patient has asthma and is wheezing, calcium channel blockers are the drug class of choice. Unlike beta-blockers and adenosine, they do not cause bronchospasm. Beta-blockers and adenosine should be used cautiously in patients with obstructive lung disease, and use should be avoided in patients with asthma. Digoxin is not contraindicated, but it is not the drug of choice due to its slow onset. Amiodarone is indicated for ventricular arrhythmias, but not PSVT. 

In acute overdose, peak serum levels > 100 pg ml may be predictive of arrhythmias and seizures. The use of sustained-release formulations and the presence of pharmacobezors in the gut may make it difficult to determine peak serum levels. Sinus tachycardia is the most common cardiac sign of theophylline toxicity. Ventricular and supraventricular tachycardia, ectopic beats, hypotension, and cardiac arrest may occur. Metabolic acidosis, hypokalemia, hypercalcemia, and hyperglycemia may be seen. Tremulousness and agitation frequently occur. Intractable seizures may occur in severe intoxications, probably secondary to adenosine receptor antagonism in the brain. Onset of seizures is a poor prognostic indicator. Persistent vomiting is commonly seen and may interfere with attempts at therapy. 

ADENOSINE Adenosine (adenocard) is a nucleoside that is administered as a rapid intravenous bolus for the acute termination of reentrant supraventricular arrhythmias. Rare cases of ventricular tachycardia in patients with otherwise normal hearts are thought to be DAD-mediated and can be terminated by adenosine. Adenosine also has been used to produce controlled hypotension during some surgical procedures and in the diagnosis of coronary artery disease. 

A) Adenosine is the drug of choice for cardioversion in patients with AV nodal arrhythmias Clearance of digoxin is increased by quinidine... 

The effects of ouabain on a sodium and potassium dependent adenosine triphosphatase (Na,K-ATPase) were studied on heart enzymes isolated from a number of mammalian species. Ouabain inhibition in vitro was correlated with in vivo changes in heart and enzyme function at doses lower than those necessary to induce toxicity and arrhythmias. ... 

Ertan C, Atar I, Gulmez O, Atar A, Ozgul A, Aydinalp A, MUderrisoglu H, Ozin B. Adenosine-induced ventricular arrhythmias in patients with supraventricular tachycardias. Ann Noninvasive Electro-cardiol 2008 13(4) 386-90. 

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