Ventricular tachycardia electrocardiogram: Difference between revisions

Jump to navigation Jump to search
VisualWikitext
No edit summary
Line 86: Line 86:
#* Rare in VT at a rapid rate.<ref>Chou's Electrocardiography in Clinical Practice Third Edition, pp. 398-409.</ref> <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:194 ISBN 1591032016</ref> <ref>Hammill S. C. Electrocardiographic diagnoses: Criteria and definitions of abnormalities, Chapter 18, MAYO Clinic, Concise Textbook of Cardiology, 3rd edition, 2007 ISBN 0-8493-9057-5</ref>
#* Rare in VT at a rapid rate.<ref>Chou's Electrocardiography in Clinical Practice Third Edition, pp. 398-409.</ref> <ref>Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:194 ISBN 1591032016</ref> <ref>Hammill S. C. Electrocardiographic diagnoses: Criteria and definitions of abnormalities, Chapter 18, MAYO Clinic, Concise Textbook of Cardiology, 3rd edition, 2007 ISBN 0-8493-9057-5</ref>


==EKG Examples==
===EKG Examples===
Shown below is an EKG depicting a [[wide complex tachycardia]] with a left bundle branch morphology at a rate of about 160/min. The [[R wave]] in lead [[Electrocardiogram#Precordial|V2]] is broad and the time from the beginning of the [[QRS]] in lead [[Electrocardiogram#Precordial|V2]] to the peak of the [[S wave]] is longer than 80 ms. No [[P wave]] activity is clearly seen. The EKG suggests ventricular tachycardia.
Shown below is an EKG depicting a [[wide complex tachycardia]] with a left bundle branch morphology at a rate of about 160/min. The [[R wave]] in lead [[Electrocardiogram#Precordial|V2]] is broad, and the time from the beginning of the [[QRS]] in lead [[Electrocardiogram#Precordial|V2]] to the peak of the [[S wave]] is longer than 80 ms. No [[P wave]] activity is clearly seen. This EKG suggests ventricular tachycardia.


[[File:Ventricular tachycardia 1.jpg|center|500px]]
[[File:Ventricular tachycardia 1.jpg|center|500px]]
Line 103: Line 103:
----
----


Shown below is an EKG with a rapid ventricular rate of about 170/min with [[wide QRS complexes]] in Lead [[Electrocardiogram#Limb|II]]  depicting ventricular tachycardia.
Shown below is an EKG with a rapid ventricular rate of about 170/min with [[wide QRS complexes]] in lead [[Electrocardiogram#Limb|II]]  depicting ventricular tachycardia.
[[Image:Lead II rhythm ventricular tachycardia Vtach VT.jpg|500px|center]]
[[Image:Lead II rhythm ventricular tachycardia Vtach VT.jpg|500px|center]]


Revision as of 15:56, 24 October 2012

Ventricular tachycardia Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Ventricular Tachycardia from other Disorders

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

Chest X Ray

Echocardiography

Cardiac MRI

Other Diagnostic Tests

Treatment

Medical Therapy

Electrical Cardioversion

Ablation

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Ventricular tachycardia electrocardiogram On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Ventricular tachycardia electrocardiogram

CDC onVentricular tachycardia electrocardiogram

Ventricular tachycardia electrocardiogram in the news

Blogs on Ventricular tachycardia electrocardiogram

to Hospitals Treating Ventricular tachycardia electrocardiogram

Risk calculators and risk factors for Ventricular tachycardia electrocardiogram

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-in Chief: Avirup Guha, M.B.B.S.[2]; Priyamvada Singh, M.D. [3]

Overview

The diagnosis of Ventricular tachycardia almost completely depends on EKG findings. The details are illustrated below. It is important to differentiate it from other wide complex tachycardias. The rate is > 100 beats per minute, and is usually 150-200 beats per minute. The QRS complex is wide (>140 milliseconds). AV dissociation is always present, but is evident in only 20% of cases of VT.

Ventricular Tachycardia

  • Ventricular tachycardia originates from a ventricular focus
  • Lasts more than 30 seconds
  • Broad QRS complexes: rate of >90 beats/minute

Paroxysmal Ventricular Tachycardia

  1. Rapid succession of three or more ectopic beats.
  2. Sustained if it lasts longer than 30 seconds.
  3. Called incessant if the tachycardia is recurrent and the episodes are interrupted by only a few sinus beats.

Electrocardiogram

EKG Findings

  1. Abnormal and wide QRS complexes with secondary ST segment and T wave changes.
    • Usual QRS duration is > 0.12 seconds, may be shorter if the ectopic focus is located in the ventricular septum.
    • The secondary ST segment and T wave changes are in a direction that is opposite the major deflection of the QRS.
    • A ventricular rate between 140 and 200 BPM.
    • When the rate is >200 and has a sine wave appearance, it is called ventricular flutter.
    • When the rate is <110 BPM it is called non-paroxysmal VT.
  2. A regular or slightly irregular (up to 0.03 seconds) rhythm.
  3. Abrupt onset and termination.
  4. AV dissociation.
    • Atrial rate slower than ventricular rate.
    • No relationship between atrial activity and ventricular activity.
    • There can be VA conduction.
      1. The RP interval is >0.11 seconds.
      2. Occurs in about 50% of cases.
      3. Uncommon when the ventricular rate is rapid (only 1/7 when the rate was>200).
  5. Capture beats.
    • Occurs when a supraventricular impulse is conducted and captures the ventricle.
    • They are rare.
  6. Fusion beats.

Brugada Criteria

  • The Brugada criteria is the commonest algorithm used to diagnose Ventricular Tachycardia.
  • In Brugada's algorithm four criteria for VT are sequentially assessed.
  • If any one of the four criteria are fulfilled diagnosis of VT is made
  • If none of the criteria are fulfilled a diagnosis of SVT is made.
  • The four criteria are as follow:
    • Check for concordance in the precordial leads. Concordance is said to be present when the QRS complexes in all the leads V1 to V6 are monophasic (all positive or all negative) with the same polarity. If any of the precordial leads has a biphasic QRS concordance is absent.
    • If the longest RS interval in any lead is >100 msec and R wave is wider than S wave a diagnosis of VT can be made.
    • If longest RS interval is less than 100 msec, presence of AV dissociation can lead to a diagnosis of VT.
    • If longest RS interval is less than 100 msec, and AV dissociation is not present then the QRS morphology is used to make the diagnosis. QRS morphology criteria consistent with VT must be present in leads V1 or V2 and in lead V6. A VT with RBBB morphology is here when the QRS polarity in lead V1 and V2 are poisitive whereas, a LBBB pattern occurs with a negative QRS polarity. If either the V1-V2 or the V6 criteria are not consistent with VT, an diagnosis of SVT is made.

Diagnostic Electrocardiographic Findings

  1. Abnormal and wide QRS complexes with secondary ST segment and T wave changes.
    • Usual QRS duration is > 0.12 seconds, may be shorter if the ectopic focus is located in the ventricular septum.
    • The secondary ST segment and T wave changes are in a direction that is opposite the major deflection of the QRS.
    • A ventricular rate between 140 and 200 BPM.
    • When the rate is >200 and has a sine wave appearance, it is called ventricular flutter.
    • When the rate is <110 BPM it is called non-paroxysmal VT.
  2. A regular or slightly irregular (up to 0.03 seconds) rhythm.
  3. Abrupt onset and termination.
  4. AV dissociation.
    • Atrial rate slower than ventricular rate.
    • No relationship between atrial activity and ventricular activity.
    • There can be VA conduction.
      1. The RP interval is >0.11 seconds.
      2. Occurs in about 50% of cases.
      3. Uncommon when the ventricular rate is rapid (only 1/7 when the rate was>200).
  5. Axis
    • Northwest quadrant is almost always VT in adults.
    • In someone with a normal QRS in sinus rhythm, a LBBB-like wide complex tachycardia with a right axis (+90 to +180) is always VT because activation in LBBB aberration always goes from right to left.
  6. Concordance
    • If all the precordial leads are positive (R) or negative (QS) the rhythm is very likely VT
  7. V1-V2 morphology
    • RBBB-morphology
      1. RsR' or rsR' in V1 favors SVT, whereas a monophasic R, Rr', qR, or RS favors VT.
      2. RBBB aberration the initial forces of the QRS are the same as in the narrow complex sinus rhythm.
    • LBBB-morphology
      1. V1 and V2 require analysis because the initial forces in V1 are often isoelectric.
      2. R wave in V1 or V2 ≥40 msec favors VT.
      3. The time from the onset of the QRS to the nadir of the S wave in V1 or V2 is ≥70 msec, VT is likely in the absence of Na channel blocking agents.
  8. V6 morphology
    • RBBB-morphology - QS or rS favors VT. Although this can be influenced by axis (it is almost always seen in VT with left axis deviation, but is seen in only approximately 50% of VT with a normal axis, even in the same patient).
    • LBBB-morphology - a qR or QS is highly predictive of VT
  9. Capture beats.
    • Occurs when a supraventricular impulse is conducted and captures the ventricle.
    • They are rare.
  10. Fusion beats.

EKG Examples

Shown below is an EKG depicting a wide complex tachycardia with a left bundle branch morphology at a rate of about 160/min. The R wave in lead V2 is broad, and the time from the beginning of the QRS in lead V2 to the peak of the S wave is longer than 80 ms. No P wave activity is clearly seen. This EKG suggests ventricular tachycardia.

Copyleft image obtained courtesy of ECGpedia,http://en.ecgpedia.org/wiki/File:E334.jpg

Shown below is an EKG with a rapid ventricular rate of nearly 190 beats per minute with wide QRS complexes depicting ventricular tachycardia.

Copyleft image obtained courtesy of ECGpedia,http://en.ecgpedia.org/wiki/File:E253.jpg

Shown below is an EKG with a rapid ventricular rate of about 170/min with wide QRS complexes in lead II depicting ventricular tachycardia.

Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/Main_Page

Shown below is an EKG with a rapid ventricular rate of about 190/min with wide QRS complex in all leads depicting ventricular tachycardia.

Copyleft image obtained courtesy of ECGpedia, http://en.ecgpedia.org/wiki/Main_Page

For more EKG examples of Ventricular tachycardia, click here.

References

  1. ↑ Chou's Electrocardiography in Clinical Practice Third Edition, pp. 398-409.
  2. ↑ Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:194 ISBN 1591032016
  3. ↑ Hammill S. C. Electrocardiographic diagnoses: Criteria and definitions of abnormalities, Chapter 18, MAYO Clinic, Concise Textbook of Cardiology, 3rd edition, 2007 ISBN 0-8493-9057-5
  4. ↑ Chou's Electrocardiography in Clinical Practice Third Edition, pp. 398-409.
  5. ↑ Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:194 ISBN 1591032016
  6. ↑ Hammill S. C. Electrocardiographic diagnoses: Criteria and definitions of abnormalities, Chapter 18, MAYO Clinic, Concise Textbook of Cardiology, 3rd edition, 2007 ISBN 0-8493-9057-5

Template:WH Template:WS

Retrieved from "https://www.wikidoc.org/index.php?title=Ventricular_tachycardia_electrocardiogram&oldid=780544"