Paroxysmal supraventricular tachycardia treatment

Common supraventricular tachycardias requiring drug treatment are atrial fibrillation (AF) or atrial flutter, paroxysmal supraventricular tachycardia (PSVT), and automatic atrial tachycardias. Other common supraventricular arrhythmias that usually do not require drug therapy are not discussed in this chapter (e.g., premature atrial complexes, wandering atrial pacemaker, sinus arrhythmia, sinus tachycardia). 

FIGURE 6-2. Algorithm for the treatment of acute (top portion) paroxysmal supraventricular tachycardia and chronic prevention of recurrences (bottom portion). Note For empiric bridge therapy prior to radiofrequency ablation procedures, calcium channel blockers (or other atrioventricular [AV] nodal blockers) should not be used if the patient has AV reentry with an accessory pathway. (AAD, antiarrhythmic drugs AF, atrial fibrillation AP, accessory pathway AVN, atrioventricular nodal AVNRT, atrioventricular nodal reentrant tachycardia AVRT, atrioventricular reentrant tachycardia DCC, direct-current cardioversion ECG, electrocardiographic monitoring EPS, electrophysiologic studies PRN, as needed VT, ventricular tachycardia.)... 

Adenosine reduces heart rate and AV conduction, although it is not a calcium antagonist. It is administered intravenously for the acute treatment of paroxysmal supraventricular tachycardia. Adenosine displays a rapid onset and short duration of action. Apart from its antiarrhythmic activity it is also a vasodilator, in particular in the coronary system. 

It is a vasopressor agent with some structural similarity to adrenaline and has a powerful alpha receptor stimulant action. The pressor response is accompanied by reflex bradycardia. It is used as a nasal decongestant and mydriatic agent and also in the treatment of paroxysmal supraventricular tachycardia. 

Paroxysmal supraventricular tachycardia, atrial fibrillation and flutter. Not of benefit in treatment of ventricular arrhythmias Miscellaneous... 

This agent also has some class lA and class II effects. It is effective for the treatment of ventricular and supraventricular tachycardias (AV nodal and accessory pathway re-entry, atrial flutter and fibrillation). Propafenone is useful in converting recent-onset atrial fibrillation or flutter to sinus rhythm, and for terminating paroxysmal supraventricular tachycardia. Its pro-ariythmic and myocardial depressant effects limit its use, especially in patients with poor ventricular function. 

Endogenous norepinephrine stimulates cardiac beta receptors. Receptor-linked cAMP-dependent protein kinases phosphorylate calcium channels to increase intracellular calcium. Elevated intracellular calcium increases conduction velocity (phase 0) and decreases the threshold potential in normal SA and AV node cells (see Figure 12.13). Beta blockers slow spontaneous conduction velocity in the SA node by approximately 10-20 percent. In addition, beta blockers can slow conduction velocity while increasing the refractory period of the AV node. These effects control the ventricular rate in atrial fibrillation or flutter and terminate paroxysmal supraventricular tachycardias. They are also safer, although somewhat less effective, than other drugs for suppression of premature ventricular complexes (PVCs). Drugs in this class approved by the FDA for treatment of various arrhythmias include propranolol, acebutolol, and esmolol. Problems with the beta blockers include drowsiness, fatigue, impotence, and depressed ventricular performance. 

Laniado S, Kronzon I, Mehta SS. Pulmonary edema a complication of metaraminol treatment of paroxysmal supraventricular tachycardia. Isr J Med Sci 1974 10(5) 504-8. 

Fassio T, Canobbio L, Gasparini G, VUlani F. Paroxysmal supraventricular tachycardia during treatment with cisplatin and etoposide combination. Oncology 1986 43(4) 219-20. 

When should drug treatment be initiated in patients with paroxysmal supraventricular tachycardia (PSVT) ... 

Quinidine, available as either quinidine sulfate or quinidine gluconate, is used in the treatment of atrial premature contraction, paroxysmal supraventricular tachycardia, supraventricular tachyarrhythmia, PVCs, and ventricular tachycardia and in prophylactic treatment after myocardial infarction. It is also used with care in the treatment of atrial... 

Verapamil, proprietaiy name Calan, is a calcium channel blocker that is effective in the treatment of various cardiovascular disorders, including angina (classical and variant), arrhythmias (paroxysmal supraventricular tachycardia), atrial flutter, atrial fibrillation, hypertrophic cardiomyopathy (idiopathic hypertrophic subaortic stenosis), hypertension, congestive heart failure, and Raynaud s phenomenon, along with the preservation of ischemic myocardium and the treatment of migraine headaches. 

Berkatens Berk Pharmaceuticals (2) treatment and prophylaxis of supraventricular tachycardia and paroxysmal supraventricular tachycardia of the reciprocating type, associated with the Wolff-Parkinson-White syndrome (3) treatment of mild to moderate hypertension and of renal hypertension... 

ChE inhibitors are the only inhibitors with well-documented efficacy, albeit limited, in the treatment of dementia symptoms of Alzheimer s disease. Physostigmine, with its shorter duration of action, is useful in the treatment of intoxication by atropine and several drugs with antichohnergic side effects it also is indicated for the treattnent of Friedreich s or other inherited ataxias. Edrophonium has been used for terminating attacks of paroxysmal supraventricular tachycardia. 

Phenylephrine is indicated in the treatment of vascular failure in shock, shock-like states, drug-induced hypotension, or hypersensitivity to overcome paroxysmal supraventricular tachycardia to prolong spinal anesthesia as a vasoconstrictor in regional analgesia and to maintain an adequate level of BP during spinal and inhalation anesthesia. Phenylephrine is a powerful postsynaptic alpha-receptor stimulant with little effect on the beta receptors of the heart (see also Figure 39). 

Verapamil (80 mg p.o. q. 6 to 8 hours) is indicated in the management of Prinzmetal s or variant angina or unstable or chronic, stable angina pectoris verapamil (0.075 to 0.15 mg/kg rv pnsh over a 2-minnte period) is indicated in the treatment of supraventricnlar tachyarrhythmias verapamil (240 to 480 mg p.o. daily) is indicated in the prevention of recurrent paroxysmal supraventricular tachycardia verapamil (240 to 320 mg p.o. daily) is indicated in the control of the ventricular rate in digitalized patients with chronic atrial flatter and/or fibrillation and verapamil (80 mg p.o. t.i.d.) is indicated in the management of hypertension. 

Fauchier JP, Cosnay P, Neel C, Rouesnel P, Bonnet P, Quilhet L. Traitement des tachycardies supraventriculaires et ventriculaires paroxystiques par le bepridil. [Treatment of supraventricular and paroxysmal ventricular tachycardia with bepridil.] Arch Mai Coeur Vaiss 1985 78(4) 612-19. 

The only calcium channel blocking drug to have been licensed for the treatment of cardiac arrhythmias is verapamil. Its main uses are in the treatment of supraventricular tachycardia (SVT) and paroxysmal SVT. Because verapamil lengthens the ERP and FRP of the AV node and prolongs AV nodal conduction time [16], it can be used to control the ventricular rate in atrial fibrillation or atrial flutter and it usually terminates re-entry arrhythmias involving the AV node [208, 209], However, intravenous verapamil should not be given to patients who have the Wolff-Parkinson-White syndrome and atrial... 

It is a anticonvulsant drug and depresses the ventricular automaticity and accelerates the AV conduction. It also reduces the duration of action potential like quinidine. It also shortens the QT interval. It mainly blocks inactivated Na+ channels. It is used for the suppression of ectopic beats and for prophylaxis of recurrent paroxysmal tachycardia and also for the treatment of rapid supraventricular or ventricular tachycardia. 

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