AV nodal reentrant tachycardia: Difference between revisions
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==Diagnosis== | ==Diagnosis== | ||
[[AVNRT history and symptoms|Symptoms]] | [[AVNRT physical examination|Physical Examination]] | [[AVNRT history and symptoms|Symptoms]] | [[AVNRT physical examination|Physical Examination]] | [[AVNRT laboratory studies|Laboratory Studies]] | [[AVNRT electrocardiogram|Electrocardiogram]] | ||
==Treatment== | ==Treatment== | ||
Revision as of 15:42, 9 September 2012
| AV nodal reentrant tachycardia | |
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| AV nodal reentrant tachycardia. In yellow, is evidenced the P wave that falls after the QRS complex. | |
| ICD-10 | I47.1 |
| ICD-9 | 426.89, 427.0 |
| MeSH | D013611 |
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AVNRT Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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AV nodal reentrant tachycardia On the Web |
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American Roentgen Ray Society Images of AV nodal reentrant tachycardia |
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Risk calculators and risk factors for AV nodal reentrant tachycardia |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords: AVNRT; AV node reentrant tachycardia; AV nodal reentry tachycardia; AV node reentry tachycardia; atrioventricular node reentrant tachycardia; atrioventricular nodal reentry tachycardia; atrioventricular node reentry tachycardia;
Overview
Historical Perspective
Pathophysiology
Classification
Risk Factors
Differentiating AVNRT from other Disorders
Epidemiology and Demographics
Natural History, Complications, Prognosis
Diagnosis
Symptoms | Physical Examination | Laboratory Studies | Electrocardiogram
Treatment
An episode of supraventricular tachycardia (SVT) due to AVNRT can be terminated by any action that transiently blocks the AV node. Various methods are possible.
Patient Position
Place the patient in a supine position to improve cerebral perfusion and reduce the odds of syncope. Placing the patient in Trendelenburg position may actually terminate the rhythm.
Vagal maneuvers
Some people with known AVNRT may be able to stop their attack by using various tricks to activate the vagus nerve. This includes carotid sinus massage (pressure on the carotid sinus in the neck), submersion of the face in ice water to trigger the diving reflex, putting the patient in Trendelenburg position or the Valsalva maneuver (increasing the pressure in the chest by attempting to exhale against a closed airway). Vagel maneuvers are contraindicated in the presence of hypotension.
Medication
Medical therapy can be initiated with AV nodal slowing drugs:
First Line Therapy
Adenosine
Beta blockers
Second Line Therapy
Numerous other antiarrhythmic drugs may be effective if the more commonly used medications have not worked; these include flecainide or amiodarone. Both adenosine and beta blockers may cause tightening of the airways, and are therefore used with caution in people who are known to have asthma. Calcium channel blockers should be avoided if there is a wide complex tacycardia and the diagnosis of AVNRT is not clearly established in so far as calcium channel blockers should be avoided in ventricular tachycardia. If the diagnosis of AVNRT is established, then non-dihydropyridine calcium channel blockers (such as verapamil) may be administered to terminate the rhythm is other agents are not effective.
Cardioversion
In very rare instances, cardioversion (the electrical restoration of a normal heart rhythm) is needed in the treatment of AVNRT. This would normally only happen if all other treatments have been ineffective, or if the fast heart rate is poorly tolerated (e.g. the development of heart failure symptoms, hypotension (low blood pressure) or unconsciousness).
Electrophysiology and Radiofrequency Ablation
After being diagnosed with AVNRT, patients can also undergo an electrophysiology (EP) study to confirm the diagnosis. Catheter ablation of the slow pathway, if successfully carried out, and cures 95% of patients with AVNRT. The risk of complications is quite low.
Prevention
Triggers such as alcohol and caffeine should be avoided.