Supraventricular Rhythms: Difference between revisions

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==Narrow complex tachycardias==
{{authors|
 
|mainauthor= [[user:Drj|J.S.S.G. de Jong]]
===Atrial flutter===
|moderator= [[user:Drj|J.S.S.G. de jong]]
{{Arrhythmias|
|supervisor=  
| name = Atrial flutter
| locatieImage = [[Image:Rhythm_atrial_flutter1.png|250px]]
| atrial_frequency = 250-350 bpm
| ventricular_frequency = 75-150bpm (3:1 of 2:1 block)
| regularity = regular (sometimes changing block)
| origin = atrial (SVT)
| p_wave = negative sawtooth in lead II
| adenosine = temporary reduced AV conduction (eg 4:1)
| example = The arrows mark the flutter waves. This is an example of an alternating 2:1 and 3:1 block. [[Image:aflutr_ecg.jpg|250px|Atrial flutter]]  
| example2 = Atrial flutter with 2:1 conduction. [[Image:ECG_Aflutt.jpg|250px|Atrial flutter]]
}}
}}
===Supraventricular tachycardias===
{| class="wikitable" border="1" width="610px"
|-
| [[Image:atrial_ventricular.png|300px]]
| [[image:SVT_overview.svg|300px]]
| [[Image:Svt_algorythm_en.png|300px]]
|-
!Arrhythmias are categorized into supraventricular and ventricular depending on their origin (below the bifurcation of the His bundle is ventricular)
!An overview of pathological supraventricular arrhythmias and their origin
!Algorithm to diagnose SVTs<cite>ACC</cite>
|}
{| class="wikitable" font-size="90%"
|- style="text-align:center;background-color:#6EB4EB;"
|+'''An overview of supraventricular tachycardias'''
|-
!
!Example (lead II)
!Regularity
!Atrial frequency
!Ventricular frequency
!Origin (SVT/VT)
!P-wave
![[Effect of adenosine]]
|-
| colspan="8" style="text-align:left;background-color:#cfefcf;" | '''Narrow complex (QRS<0.12)'''
|-
! [[Sinustachycardia]]
| [[Image:sinustachy_small.svg|200px|Sinustachycardia - a normal p wave precedes every QRS complex]]
| regular
| 100-180 bpm
| 100-180 bpm
| sinusnode (SVT)
| precedes every QRS complex
| gradual slowing
|-
! [[Atrial Fibrillation]]
| [[Image:afib_small.svg|200px|Atrial fibrillation - irregular rate, no p waves]]
| grossly irregular
| 400-600 bpm
| 75-175 bpm
| atria (SVT)
| absent
| slows down rate; irregularity remains
|-
! [[Atrial Flutter]]
| [[Image:aflutt_small.svg|200px|Atrial flutter - sawtooth in lead II with 2:1 block]]
| regular (sometimes alternating block)
| 250-350 bpm
| 75-150 bpm (3:1 or 2:1 block is most common)
| atria (SVT)
| negative sawtooth in lead II
| temporary reduced conduction (e.g. 4:1)
|-
! [[AVNRT]]
| [[Image:avnrt_small.svg|200px|ANVRT - rSR' in lead V1]]
| regular
| 180-250 bpm
| 180-250 bpm
| AV-node (SVT)
| in QRS complex (R')
| stops
|-
! [[Atrial Tachycardia]]
| [[Image:atrialtachy_small.svg|200px|Atrial tachycardia - like sinustachycardia but the p wave has a different morphology]]
| regular
| 120-250 bpm
| 75-200 bpm
| atria
| precedes QRS, p wave differs from sinus-p
| temporary AV-block
|-
! [[AVRT|Atrio-Ventricular Reentry Tachycardia (AVRT)- orthodromic]]
| [[Image:avrt_small.svg|200px|AVRT - inverted p wave behind every QRS complex]]
| regular
| 150-250 bpm
| 150-250 bpm
| circle: av-node - ventricles - bypass - atria
| RP < PR
| stops
|-
! [[AVJT|AV junctional tachycardia]]
| [[Image:avnodal_small.svg|200px|AV junctional tachycardia - no or inverted p-waves within QRS complex]]
| regular
| 60-100 bpm
| 70-130 bpm
| AV node
| RP < PR
| reduces rate
|-
| colspan="8" style="text-align:left;background-color:#cfefcf;" | '''Wide complex (QRS>0.12)'''
|-
! [[Supraventricular tachycardia with block]]
| [[Image:atrial_tachy_with_LBBB_leadII.svg|200px|SVT with block - any SVT combined with LBBB or RBBB]]
| (ir)regular depending on SVT
| 100-250 bpm
| 75-200 bpm
| atria (SVT)
| absent
| temporary increased AV-block (eg 4:1)
|-
! [[AVRT|Atrio-ventricular Reentry Tachycardia (AVRT) - antidrome]]
|
| regular
| 150-250 bpm
| 150-250 bpm
| circular: bypass - atria - av-node - ventricles
| RP < PR
| stops
|-
|}


 
{{Box|
During atrial flutter the atria depolarize in an organized circular movement. This is caused by [[Arrhythmias#Re-entry|re-entry]]. The atria contract typically at around 300 bpm, which results in a fast sequence of p-waves in a sawtooth pattern on the ECG. For most AV-nodes this is way to fast to be able to conduct the signal to the ventricles, so typically there is a 2:1, 3:1 or 4:1 block, resulting in a ventricular frequency of 150, 100 or 75 bpm respectively. Often the grade of block changes every couple of beats, resulting in e.g. 2:1, or 3:1 blocks and a somewhat irregular ventricular heart rate. The saw-tooth is especially prominent in lead II, this lead normally shows constant electrical activity: it is never horizontal. Causes and risk of atrial flutter are comparable to atrial fibrillation.
===Supraventricular [[Ectopic Beats|ectopic beats]]===
{{clr}}
*[[Atrial Premature Complexes]]
 
*[[Wandering Pacemaker]]
===Atrial fibrillation===
*[[AV-nodal complexes]]
{{main|Atrial Fibrillation}}
{{Arrhythmias|
| name = Atrial fibrillation
| locatieImage = [[Image:Rhythm_atrical_fibrillation2.png|250px]]
| atrial_frequency = 400-600 bpm
| ventricular_frequency = 75-175 bpm
| regularity = irregular
| origin = atria (SVT)
| p_wave = absebt
| adenosine = reduces heart rate
| example = [[Image:afib_ecg.jpg|250px|Atrial fibrillation]]
}}
}}
During atrial fibrillation the atria show chaotic depolarisation with multiple foci. Mechanically the atria stop contracting after several days to weeks of atrial fibrillation, the result of the ultra-rapid depolarisations that occur in the atria, typically around 400 bpm, but up to 600 bpm. At the AV node 'every now and then' a beat is conducted to the ventricles, resulting in an irregular ventricular rate, which is the typical ECG characteristic of atrial fibrillation. Sometimes atrial fibrillation results in a course atrial flutter wave on the ECG, but the baseline can also be flat. A flat baseline is more often seen in long standing atrial fibrillation. The cardiac stroke volume is reduced by 10-20% during atrial fibrillation, as the 'atrial kick' is missing and because the heart does not have time to fill at the often higher ventricular rate. Causes; age (+- 10% of 70+ year olds and 15% of 90+ year olds have AFIB <cite>kelley</cite>), ischemia, hyperthyreoidism, alcohol abuse.
{{Box|
Risc: thrombo-embolisation of thrombi that form in the atrial caverns as a result of the reduced atrial motion. These thrombi can emblise to the brain and cause strokes.
===Also read===
 
*[[Introduction to Arrhythmias]]
'''Atrial flutter can be catechorized as follows:'''
*[[Mechanisms of Arrhythmias]]
*'''First documented episode:'''
*[[Sinus node rhythms and arrhythmias]]
*'''Recurrent atrial fibrillation:''' after two or more episodes.
*[[Junctional Tachycardias]]
*'''Paroxysmal atrial fibrillation:''' if recurrent atrial fibrillation spontaneously converts to sinus rhythm.
*[[Ventricular Arrhythmias]]
*'''Persisting atrial fibrillation:''' if an episode of atrial fibrillation persists more than 7 days.
*'''Permanent atrial fibrillation:''' if atrial fibrillation persists after an effort of electrical or chemical cardioversion
 
''Lone AF'' is atrial fibrillation in patients younger than 60 years in whom no clinical or electrocardiographic signs of heart or lung disease are present. These patiens have a favourable prognosis regarding thrombo-embolic events.
 
''Non-valvular atrial fibrillation'' is atrial fibrillation in patients without heart valve disease or heart valve replacement or repair. <cite>ESCAF</cite>
 
{{clr}}
 
===Atrial Tachycardia===
Atrial tachcyardia is a more or less regular heart rate > 100 bpm that does not origin from the sinus node. The p-waves therefore have a different configuration and easily be recognized if the are negative in AVF.
 
===AVNRT===
{{Arrhythmias|
| name = AV Nodal Re-entry Tachycardia (AVNRT)
| locatieImage =
| atrial_frequency = 180-250 bpm
| ventricular_frequency = 180-250 bpm
| regularity = regular
| origin = AV node
| p_wave = inside or right after the QRS complex
| adenosine = terminates the arrhythmia(!)
| example = The first part of this example shows AVNRT. After injection of adenosine, the arrhythmia terminates. [[Image:avnrt_ecg.jpg|250px|AV Nodal Re-entry Tachycardia (AVNRT) terminated by adenosine injection]]
| example2 = [[Image:avnrt_ecg2.jpg|250px|AV Nodal Re-entry Tachycardia (AVNRT)]]
}}
}}
 
{{Box|
An '''AV Nodal Re-entry Tachycardia (AVNRT)''' is a rapid tachycardia with a typical frequency around 200 bpm. The tachycardia origin is the AV node. A prerequisite for AVNRT is a slow and fast pathway in the AV node, most often caused by degradation of the AV nodular tissue. The dual pathways facilitate [[Arrhythmias#Re-entry|re-entry]].
==References==
 
<biblio>
Two sensitive characteristics to identify AVNRT on the ECG are:
#ACC pmid=14563598
* R'. This is a small secondary R wave. It resembles a [[#Bundle branch block|right bundel branch block]], but the QRS width stays < 120ms.
</biblio>
* RP << 100ms. The distance between the R and P waves is less than 100ms.
{{clr}}
 
===Atrio-ventricular Reentry Tachycardia AVRT===
 
Atrio-ventricular Re-entry Tachycardias are somewhat similar to [[#AVNRT|AVNRT]]. An important diffence however is that an accessory bundle is present in AVRT. This accessory bundle connects the atria and ventricles, thereby bypassing the AV node. The most common type of accessory bundle is a bundle of Kent. AVRTs can result from abnormal retrograde conduction (from ventricles to the atria) and anterorade conduction (from atria to ventricles). This results in two type of circular tachycardias:
 
#'''Orthodrome AV Re-entry Tachcardia''' (conduction retrogarde through the accessory bundle). Usually a narrow QRS complex preceded by a p-wave.
#'''Antidrome Atrioventricular Re-entry Tachcardia''' (anterogarde conduction through the abnormal accessory bundle). The ECG shows wide QRS complexes followed by retrograde P-waves. The RP-time is >> 100ms.
#'''Concealed Bypass Tract'''
 
===AV junctional tachycardia===
{{Arrhythmias|
| name = AV junctional tachycardia / Junctional Ectopic Tachycardia (JET)
| locatieImage =
| atrial_frequency = 60-100 bpm
| ventricular_frequency = 70-130 bpm
| regularity = regular
| origin = AV node
| p_wave = RP > RP
| adenosine = slows down heartrate
| example = Lead II shows competition between the sinus rate and the nodal tachycardia. After around the third beat, some sinus beats are conducted and followed by QRS complexes. Thereafter the nodal tachycardia takes over resulting in a negative p-wave around the 8th beat, the proof of a junctional rhythm.[[Image:JEt.jpg|250px|Junctional Ectopic Tachycardia (JET)]]
}}
}}
{{clr}}
[[Category:ECG Textbook]]

Latest revision as of 19:09, 23 August 2011

Author(s) J.S.S.G. de Jong
Moderator J.S.S.G. de jong
Supervisor
some notes about authorship

Supraventricular tachycardias

Atrial ventricular.png SVT overview.svg Svt algorythm en.png
Arrhythmias are categorized into supraventricular and ventricular depending on their origin (below the bifurcation of the His bundle is ventricular) An overview of pathological supraventricular arrhythmias and their origin Algorithm to diagnose SVTs[1]
An overview of supraventricular tachycardias
Example (lead II) Regularity Atrial frequency Ventricular frequency Origin (SVT/VT) P-wave Effect of adenosine
Narrow complex (QRS<0.12)
Sinustachycardia Sinustachycardia - a normal p wave precedes every QRS complex regular 100-180 bpm 100-180 bpm sinusnode (SVT) precedes every QRS complex gradual slowing
Atrial Fibrillation Atrial fibrillation - irregular rate, no p waves grossly irregular 400-600 bpm 75-175 bpm atria (SVT) absent slows down rate; irregularity remains
Atrial Flutter Atrial flutter - sawtooth in lead II with 2:1 block regular (sometimes alternating block) 250-350 bpm 75-150 bpm (3:1 or 2:1 block is most common) atria (SVT) negative sawtooth in lead II temporary reduced conduction (e.g. 4:1)
AVNRT ANVRT - rSR' in lead V1 regular 180-250 bpm 180-250 bpm AV-node (SVT) in QRS complex (R') stops
Atrial Tachycardia Atrial tachycardia - like sinustachycardia but the p wave has a different morphology regular 120-250 bpm 75-200 bpm atria precedes QRS, p wave differs from sinus-p temporary AV-block
Atrio-Ventricular Reentry Tachycardia (AVRT)- orthodromic AVRT - inverted p wave behind every QRS complex regular 150-250 bpm 150-250 bpm circle: av-node - ventricles - bypass - atria RP < PR stops
AV junctional tachycardia AV junctional tachycardia - no or inverted p-waves within QRS complex regular 60-100 bpm 70-130 bpm AV node RP < PR reduces rate
Wide complex (QRS>0.12)
Supraventricular tachycardia with block SVT with block - any SVT combined with LBBB or RBBB (ir)regular depending on SVT 100-250 bpm 75-200 bpm atria (SVT) absent temporary increased AV-block (eg 4:1)
Atrio-ventricular Reentry Tachycardia (AVRT) - antidrome regular 150-250 bpm 150-250 bpm circular: bypass - atria - av-node - ventricles RP < PR stops




References

  1. Blomström-Lundqvist C, Scheinman MM, Aliot EM, Alpert JS, Calkins H, Camm AJ, Campbell WB, Haines DE, Kuck KH, Lerman BB, Miller DD, Shaeffer CW, Stevenson WG, Tomaselli GF, Antman EM, Smith SC Jr, Alpert JS, Faxon DP, Fuster V, Gibbons RJ, Gregoratos G, Hiratzka LF, Hunt SA, Jacobs AK, Russell RO Jr, Priori SG, Blanc JJ, Budaj A, Burgos EF, Cowie M, Deckers JW, Garcia MA, Klein WW, Lekakis J, Lindahl B, Mazzotta G, Morais JC, Oto A, Smiseth O, Trappe HJ, and European Society of Cardiology Committee, NASPE-Heart Rhythm Society. ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias--executive summary. a report of the American college of cardiology/American heart association task force on practice guidelines and the European society of cardiology committee for practice guidelines (writing committee to develop guidelines for the management of patients with supraventricular arrhythmias) developed in collaboration with NASPE-Heart Rhythm Society. J Am Coll Cardiol. 2003 Oct 15;42(8):1493-531. DOI:10.1016/j.jacc.2003.08.013 | PubMed ID:14563598 | HubMed [ACC]
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