Arrhythmia - Supraventricular Tachicardia Treatment and Medication

7/21/2019 Arrhythmia - Supraventricular Tachicardia Treatment and Medication

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Approach Considerations

Acute management of paroxysmal supraventricular tachycardia(PSVT)includes controlling the rate and preventing hemodynamic collapse. If thepatient is hypotensive or unstale! immediate cardioversion "ith sedation

must e performed. If the patient is stale! vagal maneuvers can e used toslo" the heart rate and to convert to sinus rhythm. If vagal maneuvers are notsuccessful! adenosine can e used in increasing doses. If adenosine does not"or#! atrioventricular (AV) nodal loc#ing agents li#e calcium channel loc#ersor eta$loc#ers should e used! as most patients "ho present "ith PSVThave AV nodal reentrant tachycardia (AV%&T) or AV reentrant tachycardia(AV&T). These arrhythmias depend on AV nodal conduction and therefore cane terminated y transiently loc#ing this conduction.

Patients "ith symptomatic 'olff$Par#inson$'hite ('P') syndrome should

not e treated "ith calcium channel loc#ers or digoxin unless the path"ay is#no"n to e of lo" ris# (long anterograde refractory period). This is ecauseof the potential for rapid ventricular rates should atrial firillation or atrial flutter occur! "hich can result in cardiac arrest.

Patients "ith preexcited atrial firillation should not e treated "ithintravenous AV nodal loc#ing agents! such as adenosine! eta$loc#ers!calcium channel loc#ers! and digoxin. &ather! if the patient ishemodynamically stale! intravenous procainamide should e administered. If the patient is unstale! direct current cardioversion should e performed.

Electrical cardioversion

lectrical cardioversion is the most effective method for restoring sinusrhythm. Synchronied cardioversion starting at *+, can e used immediatelyin patients "ho are hypotensive! have pulmonary edema! have chest pain "ithischemia! or are other"ise unstale.

If atrial firillation has een present for longer than -$/ hours! defercardioversion until the patient has een ade0uately anticoagulated to preventthromoemolic complications.1+! 23! 4! *+! *5! *-! *2! 56

Inpatient care

Patients "ho re0uire cardioversion! are unstale! and have comorid illnessesshould e admitted to the hospital. Patients "ho are young! healthy! andasymptomatic may e discharged and advised to have a follo"$upexamination "ith their primary physician or cardiologist. If the patient is having



more fre0uent episodes of paroxysmal SVT and medical therapy is notsuccessful or desired! then radiofre0uency catheter alation should eproposed.

Diet and activity

7ietary changes depend on underlying medical prolems. Changes inphysical activity depend on underlying cardiac prolems and othercomoridities.

Consultations

A cardiologist should e consulted for patients "ith fre0uent episodes ofparoxysmal SVT! syncope! and8or preexcitation syndromes. Consultation "itha cardiologist should also e otained for patients in "hom medicalmanagement has failed.

An electrophysiologist should e consulted for patients considered forradiofre0uency catheter alation. Pediatric patients should e referred to apediatric electrophysiologist.

Transfer

Patient transfer to a center "ith radiofre0uency catheter alation is reasonaleif this therapy is planned. Alternatively! patients can e discharged home andscheduled for outpatient procedures. xceptions include patients "ith

syncope! profound symptoms! or preexcited atrial firillation or atrial flutter.

Monitoring

Patients treated medically should e monitored regularly. Patients cured "ithradiofre0uency catheter alation are typically seen once in a follo"$upexamination follo"ing the procedure! then as needed for recurrent symptoms.

Vagal 9aneuvers

The first$line treatment in hemodynamically stale patients! vagal maneuvers!

such as reath$holding and the Valsalva maneuver (ie! having the patient ear do"n as though having a o"el movement)! slo" conduction in the AV nodeand can potentially interrupt the reentrant circuit.

Carotid massage is another vagal maneuver that can slo" AV nodalconduction. 9assage the carotid sinus for several seconds on thenondominant cereral hemisphere side. This maneuver is usually reserved for



young patients. 7ue to the ris# of stro#e from emoli! auscultate for ruitsefore attempting this maneuver. 7o not perform carotid massage on othsides. A Valsalva maneuver! if performed properly y the patient! canfre0uently avert an attac#.

Short$Term Pharmacologic 9anagement'hen SVT is not terminated y vagal maneuvers! short$term managementinvolves intravenous adenosine or calcium channel loc#ers. Adenosine is ashort$acting drug that loc#s AV node conduction: it terminates 4+; oftachycardias due to AV%&T or AV&T. Adenosine does not usually terminateatrial tachycardia! although it is effective for terminating S%&T.1+! 23! 4! *! *-! 56

Typical adverse effects of adenosine include flushing! chest pain! anddiiness. These effects are temporary ecause adenosine has a very short

half$life of 5+$-+ seconds.1*26

<ther alternatives for the acute treatment of SVT include calcium channelloc#ers! such as verapamil and diltiaem! as "ell as eta$loc#ers! such asmetoprolol or esmolol. Verapamil is a calcium channel loc#er that also has

AV loc#ing properties. It has a longer half$life than adenosine and may helpto maintain sinus rhythm follo"ing the termination of SVT. It is alsoadvantageous for controlling the ventricular rate in patients "ith atrialtachyarrhythmia.14! **! 4! *+! 5+! *-! *2! 556

Wide-complex tachycardia Acute management of a "ide$complex tachycardia in a hemodynamicallyunstale patient re0uires immediate cardioversion! "hereas in a stalepatient! intravenous procainamide! propafenone! or flecainide is acceptale.

Amiodarone is preferred in patients "ith impaired left ventricular function or inpatients "ith heart failure or structural heart disease.1*36

Atrial fibrillation and atrial flutter

The treatment of atrial firillation and atrial flutter involves controlling the

ventricular rate! restoring the sinus rhythm! and preventing emoliccomplications. The ventricular rate is controlled "ith calcium channel loc#ers!digoxin! amiodarone! and eta$loc#ers. The sinus rhythm may e restored"ith either pharmacologic agents or electrical cardioversion. 9edications suchas iutilide! propafenone! and flecainide convert atrial firillation and atrialflutter of short duration to sinus rhythm. Since atrial firillation and atrial flutterincrease ris# of stro#e or cererovascular accidents! anticoagulation is usually



recommended. 7rugs li#e "arfarin! as "ell as novel oral anticoagulant agentsli#e daigatran! rivaroxaan! and apixaan! may e used for anticoagulation.1*=! */! *46

>ong$Term Pharmacologic 9anagement

The choice of long$term therapy for patients "ith SVT depends on the type oftachyarrhythmia that is occurring and the fre0uency and duration of episodes!as "ell as the symptoms and the ris#s associated "ith the arrhythmia (eg!heart failure! sudden death). valuate patients on an individual asis! andtailor treatment to the est therapy for the specific tachyarrhythmia.

Patients "ith paroxysmal SVT may initially e treated "ith calcium channelloc#ers! digoxin! and8or eta$loc#ers. Class IA! IC! or III antiarrhythmicagents are used less fre0uently ecause of the success of radiofre0uency

catheter alation.1+! 23! 4! *+! *5! *-! *2! 5! 3+6

&adiofre0uency Catheter Alation

Prior to the advent of percutaneous radiofre0uency catheter alation! opencardiac surgical procedures "ere the only means of curing paroxysmal SVT.Currently! ho"ever! open surgical procedures are rarely performed! andcatheter alation is considered the first$line treatment of many recurrentsymptomatic SVTs. It is generally performed using conscious sedation in anoutpatient setting or "ith an overnight hospital stay for oservation.

Catheter alation involves focally alating the crucial component of thearrhythmic mechanism. ?or example! in AV%&T! the slo" path"ay is alated!"hich prevents the reentry cycle. The accessory path"ay is targeted inpatients "ith AV&T. ?ocal atrial tachycardia! atrial flutter! and! in some cases!atrial firillation can also e cured "ith alation.

Consider catheter alation for any patient "ith symptomatic paroxysmal SVTin "hom long$term medical treatment is not effectively tolerated or desired. Inaddition! ecause of the ris# of sudden cardiac death! perform catheteralation on patients "ith symptomatic 'P' syndrome.14! +! 5+! 5! 526 The optimal

management strategy for patients "ith asymptomatic preexcitation syndromesremains uncertain.135! 3-! 54! 4! 526

The efficacy of catheter alation often exceeds that of medical therapy forsymptoms! recurrences re0uiring medical intervention! and the prevention ofconse0uences! such as defirillator discharges in patients "ith an implanteddefirillator and SVT. (A study y 9ainigi et al found that SVT causes a



significant numer of inappropriate implantale cardioverter$defirillatortherapies and that catheter alation is an effective strategy to avoid theseinappropriate therapies.1326 ) Catheter alation is more than 4+; effective incuring paroxysmal SVT.

Complications

Potential complications of radiofre0uency catheter alation include thefollo"ing@

• ematoma

• Bleeding

• Infection

• Pseudoaneurysm

• 9yocardial infarction

• Cardiac preformation

• eart loc# that re0uires a pacema#er

• Thromoemolic complications $ Including deep venous thromosis and

systemic emolism

• Cardiac tamponade

• Stro#e

• %eed for emergency surgery

• &adiation urn

•

Increased ris# of malignancy $ >ifetime ris# of fatal malignancy as aresult of radiation exposure is lo"

• 7eath $ &is# is approximately +.5;

Bohnen et al performed a prospective study to assess the incidence andpredictors of maor complications from contemporary catheter alationprocedures. 9aor complication rates ranged et"een +./; (SVT) and 3;(ventricular tachycardia associated "ith structural heart disease)! dependingon the alation procedure performed. The investigators reported that renalinsufficiency "as the only independent predictor of a maor complication.136



MEDICATION

9edication Summary

As previously stated! short$term management of supraventricular tachycardia(SVT) involves intravenous adenosine or calcium channel loc#ers.

In cases of "ide$complex tachycardia! hemodynamically stale patients cane treated "ith intravenous procainamide! propafenone! or flecainide.

Amiodarone is preferred in patients "ith impaired left ventricular function or inpatients "ith heart failure or structural heart disease.1*36

Treatment for atrial firillation and atrial flutter includes medications thatcontrol the ventricular rate (calcium channel loc#ers! digoxin! amiodarone!

eta$loc#ers)! restore the sinus rhythm (such as iutilide! flecainide!amiodarone! propafenone)! and prevent emolic complications.

>ong$term pharmacologic therapy for patients "ith SVT depends on the typeof tachyarrhythmia that is occurring and the fre0uency and duration ofepisodes! as "ell as the symptoms and the ris#s associated "ith thearrhythmia (eg! heart failure! sudden death).

Cardiovascular! <ther

Class ummaryThese medications are used to treat or prevent arrhythmia.

Vie" full drug information

!lecainide "Tambocor#

?lecainide loc#s sodium channels! producing a dose$related decrease inintracardiac conduction in all parts of heart. The drug increases electricalstimulation of threshold of ventricle! IS$Pur#ine system. ?lecainide shortensphase - and 2 repolariation! resulting in a decreased action potential

duration and effective refractory period.

This agent is indicated for the treatment of paroxysmal atrial firillation8flutter(PA?) associated "ith disaling symptoms. It is also indicated for paroxysmalSVTs! including atrioventricular nodal reentrant tachycardia (AV%&T)!atrioventricular reentrant tachycardia (AV&T)! and other SVTs of unspecified

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mechanism associated "ith disaling symptoms in patients "ithout structuralheart disease.

In addition! ?lecainide is indicated for the prevention of documented! life$threatening ventricular arrhythmias! such as sustained ventricular tachycardia.

It is not recommended for less severe ventricular arrhythmias! even if patientsare symptomatic.


$ropafenone "%ythmol#

Propafenone shortens the upstro#e velocity (phase +) of monophasic actionpotentials. It reduces the fast in"ard current carried y sodium ions in Pur#inefiers and! to a lesser extent! myocardial fiers. Propafenone may increasethe diastolic excitaility threshold and prolong the effective refractory period. It

also reduces spontaneous automaticity and depresses triggered activity.

Propafenone is indicated for the treatment of documented! life$threateningventricular arrhythmias! such as sustained ventricular tachycardia. It appearsto e effective in the treatment of SVTs! including atrial firillation and flutter.The drug is not recommended for patients "ith less severe ventriculararrhythmias! even if the patients are symptomatic.


Adenosine "Adenocard#

Adenosine is the first$line medical treatment for the termination of paroxysmalSVT. It is a short$acting agent that alters potassium conductance into cells andresults in hyperpolariation of nodal cells. This increases the threshold totrigger an action potential and results in sinus slo"ing and the loc#age of AVconduction.

Adenosine is effective in terminating AV%&T and AV&T. 9ore than 4+; ofpatients convert to sinus rhythm "ith adenosine at 5-mg. As a result of itsshort half$life! adenosine is est administered in an antecuital vein as anintravenous olus! follo"ed y rapid saline infusion.


Digoxin "&anoxin#

7igoxin indirectly increases vagal activity! therey decreasing conductionvelocity through the AV node. This can result in termination of paroxysmalSVT.

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Calcium Channel Bloc#ers

Class ummary

Class IV calcium channel loc#ers decrease the conduction velocity and

prolong the refractory period.


'erapamil "Isoptin( Calan( 'erelan( Covera-)#

Calcium channel loc#ers prevent calcium influx into the slo" channels of the AV node! decrease the conduction velocity! and prolong the refractory period!"hich effectively terminates reentrant conduction.


Diltia*em "Cardi*em( Tia*ac( Dilacor +%#

7iltiaem is similar to verapamil. This agent decreases the conduction velocityin the AV node and increases the refractory period via a loc#ade of calciuminflux. This! in turn! stops the reentrant phenomenon.

Beta$Bloc#ers! Beta$5 Selective

Class ummary

These agents slo" the sinus rate and decrease AV nodal conduction. Beta$loc#ers no" have more of a secondary role in A? rate control. Carefully

monitor lood pressure.


Atenolol "Tenormin#

Atenolol selectively loc#s eta$5 receptors! "ith little or no effect on eta$-types. Atenolol is excellent for use in patients at ris# for experiencingcomplications from eta$loc#ade! particularly those "ith reactive air"aydisease! mild$to$moderate >V dysfunction! and8or peripheral vascular disease.

Vie" full drug informationEsmolol ",revibloc#

smolol is a short$acting eta$loc#er that aolishes reentry$inducedparoxysmal SVT y increasing the refractory period of the AV node.

It selectively loc#s eta$5 receptors! "ith little or no effect on eta$- receptortypes. It is particularly useful in patients "ith elevated arterial pressure!

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especially if surgery is planned. It has een sho"n to reduce episodes ofchest pain and clinical cardiac events compared "ith placeo. It can ediscontinued aruptly if necessary. It is useful in patients at ris# forexperiencing complications from eta$loc#ade! particularly those "ithreactive air"ay disease! mild$to$moderate >V dysfunction! and8or peripheralvascular disease. A short half$life of / min allo"s for titration to the desiredeffect and 0uic# discontinuation if needed.


Metoprolol "&opressor( Toprol +&#

9etoprolol is a selective eta$5 adrenergic receptor loc#er that decreasesthe automaticity of contractions. 7uring intravenous administration! carefullymonitor lood pressure! heart rate! and CD.

Beta$loc#ers! %onselectiveClass ummary

These agents increase the refractory period of the AV node. Beta$loc#ersthat are effective in treating paroxysmal SVT include propranolol! esmolol!metoprolol! atenolol! and nadolol.


$ropranolol "Inderal &A( Inno$ran +&#

Beta$loc#ers aolish reentry$induced paroxysmal SVT y increasing therefractory period of the AV node.


adolol "Corgard#

%adolol is fre0uently prescried ecause of its long$term effect. It reduces theeffect of sympathetic stimulation on the heart. %adolol decreases conductionthrough the AV node and has negative chronotropic and inotropic effects.Patients "ith asthma should use cardioselective eta$loc#ers.

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Arrhythmia - Supraventricular Tachicardia Treatment and Medication