Classification of arrhythmias





Bradyarrhythmias are due to sinus nodal disease ( Box 1.1 ) or atrioventricular conduction block ( Box 1.2 ).



Box 1.1

Sinus Node Dysfunction (with accompanying symptoms)





  • Sinus bradycardia



  • Sinoatrial exit block



  • Sinus pauses (>3 s)



  • Sinus node arrest



  • Tachycardia-bradycardia syndrome



  • Chronotropic incompetence *




* Maximum predicted heart rate is calculated as 220 – age (y).




Box 1.2

AV. Atrioventricular.

Atrioventricular Block





  • First-degree AV block



  • Second-degree AV block




    • Type I AV block (Mobitz I or Wenckebach)



    • Type II AV block (Mobitz II)




  • Third-degree (complete) AV block.




Tachyarrhythmias are classified as ventricular or supraventricular . The term supraventricular literally indicates tachycardias (atrial rates > 100 beats per minute [bpm] at rest) arising from the His bundle or above. Traditionally, the term supraventricular tachycardia (SVT) has been used to describe all tachycardias that are not solely infra-Hisian in origin, including atrial fibrillation and tachycardias such as atrioventricular reentry as a result of an accessory connection that involves both the atrium and ventricle ( Box 1.3 ). The term narrow QRS tachycardia indicates tachycardia with a QRS duration ≤ 120 milliseconds (ms). A wide QRS tachycardia refers to one with a QRS duration > 120 ms.



Box 1.3

AV, Atrioventricular.

Classification of Tachyarrhythmias


Atrial tachycardias





  • Sinus tachycardia



  • Physiologic sinus tachycardia



  • Inappropriate sinus tachycardia



  • Sinus nodal reentrant tachycardia



  • Focal atrial tachycardia




    • Microreentry



    • Automatic




  • Multifocal atrial tachycardia



  • Macroreentrant atrial tachycardia



  • Cavotricuspid isthmus dependent




    • Typical atrial flutter, counterclockwise (common) or clockwise (reverse)



    • Other cavotricuspid isthmus dependent




  • Noncavotricuspid isthmus dependent




    • Right atrial



    • Left atrial




  • Atrial fibrillation



Atrioventricular junctional tachycardias





  • Atrioventricular nodal reentrant tachycardia



  • Typical



  • Atypical



  • Nonreentrant junctional tachycardia



  • Junctional ectopic tachycardia (focal or automatic junctional tachycardia)



  • Other nonreentrant variants



Atrioventricular tachycardias





  • Orthodromic




    • Concealed or manifest atrioventricular accessory pathway conducting in retrograde direction, with anterograde conduction through the atrioventricular node node/His-Purkinje system



    • Nodofascicular or nodoventricular bypass tract conducting in retrograde direction, with anterograde conduction through the atrioventricular node/His-Purkinje system




  • Antidromic




    • Atrioventricular accessory pathway conducting anterograde with retrograde conduction through the AV node or, rarely, over another pathway



    • Atriofascicular, atrioventricular, nodofascicular, or nodoventricular bypass tract conducting in the anterograde direction, with retrograde conduction through the AV node or rarely through another pathway




Ventricular tachycardias





  • Monomorphic ventricular tachycardia




    • Scar-related reentry



    • Bundle branch reentry



    • Idiopathic (automatic, reentrant, interfascicular)




  • Accelerated idioventricular rhythm



  • Polymorphic ventricular tachycardia



  • Pleomorphic ventricular tachycardia



  • Bidirectional ventricular tachycardia



  • Torsades de pointes



  • Ventricular flutter



  • Ventricular fibrillation


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Jun 26, 2021 | Posted by in CARDIOLOGY | Comments Off on Classification of arrhythmias
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