Most Common ECG Patterns You Should Know

00:12:14
https://www.youtube.com/watch?v=vq3ba4BhddM

Summary

TLDRCette vidéo traite des découvertes courantes et essentielles de l'électrocardiogramme (ECG) en médecine. Elle commence par expliquer le rythme sinusal, qui est le rythme normal du cœur avec des ondes P régulières suivies de complexes QRS. Ensuite, elle aborde la fibrillation auriculaire, une activité électrique anormale qui rend les contractions des fibres musculaires de l'oreillette désynchronisées, entraînant un rythme irrégulier du cœur identifiable par une absence d'ondes P claires sur l'ECG. Le flutter auriculaire est aussi discuté, se caractérisant par une activité électrique coordonnée et un modèle en dents de scie sur l'ECG. Les blocs de branche et les différents blocs AV sont aussi présentés, ainsi que les contractions prématurées qui sont courantes mais généralement bénignes. Le document conclut avec l'importance de reconnaître des conditions potentiellement mortelles comme la tachycardie ventriculaire et la fibrillation ventriculaire ainsi que l'élévation du segment ST souvent associée aux infarctus du myocarde. Ce contenu permet de mieux saisir l'interprétation d'un ECG.

Takeaways

  • 📉 Le rythme sinusal est le rythme normal avec des ondes P suivies de complexes QRS.
  • ❤️ La fibrillation auriculaire entraîne un rythme cardiaque irrégulier identifiable par l'absence d'ondes P claires.
  • ⚡ Le flutter auriculaire se caractérise par une activité en dents de scie sur l'ECG.
  • 🔌 Les blocs de branche, gauche ou droite, montrent des complexes QRS élargis.
  • 🕒 Un bloc AV du premier degré montre un intervalle PR prolongé.
  • 💥 Les contractions prématurées sont généralement bénignes sauf si elles sont fréquentes.
  • ⚠️ La tachycardie ventriculaire peut dégénérer en fibrillation ventriculaire, menaçant la vie.
  • 🔍 L'élévation du segment ST est souvent liée à un infarctus du myocarde.
  • ⛔ Les rythmes de l'arrêt cardiaque incluent la fibrillation ventriculaire et l'asystolie.
  • 📑 Une bonne interprétation de l'ECG est cruciale pour diagnostiquer des conditions cardiaques.

Timeline

  • 00:00:00 - 00:05:00

    La vidéo commence par expliquer le rythme sinusal normal du cœur, en décrivant comment les ondes P régulières suivies d'un complexe QRS indiquent une conduction normale des signaux électriques de l'oreillette droite aux ventricules. Il est mentionné que si la fréquence cardiaque est inférieure à 60 battements par minute, cela s'appelle une bradycardie sinusale, et si elle est supérieure à 100, une tachycardie sinusale. Ensuite, la fibrillation auriculaire est décrite, avec des activités électriques anormales qui mènent à une quivering des fibres musculaires auriculaires, sans ondes P claires sur l'ECG et un rythme cardiaque irrégulièrement irrégulier.

  • 00:05:00 - 00:12:14

    Les blocs de branche sont décrits, avec des blocs de branche gauche présentant un complexe QRS large et des formes spécifiques des ondes S et R. Les blocs AV sont ensuite expliqués, commençant par le bloc AV de premier degré avec une prolongation de l'intervalle PR. Ils continuent avec des explications sur les blocs AV de second degré de types Mobitz 1 et Mobitz 2, et le bloc AV de troisième degré où il n'y a pas d'association entre les contractions auriculaires et ventriculaires. Finalement, la tachycardie ventriculaire et la fibrillation ventriculaire sont définies comme des rythmes ECG critiques, avec la tachycardie résultant potentiellement en un arrêt cardiaque, et la fibrillation étant un rythme létal. Les anomalies ECG comme l'élévation du segment ST sont abordées, en rapport avec des pathologies comme l'infarctus du myocarde.

Mind Map

Mind Map

Frequently Asked Question

  • Qu'est-ce que le rythme sinusal ?

    Le rythme sinusal est le rythme normal du cœur, caractérisé par des ondes P régulières suivies d'un complexe QRS.

  • Comment reconnaître la fibrillation auriculaire sur un ECG ?

    La fibrillation auriculaire se caractérise par l'absence de véritables ondes P et un rythme cardiaque irrégulièrement irrégulier.

  • Quelle est la différence entre la fibrillation auriculaire et le flutter auriculaire ?

    Le flutter auriculaire présente une activité électrique coordinée dans les oreillettes avec un rythme en dents de scie sur l'ECG, contrairement à la fibrillation auriculaire.

  • Qu'est-ce qu'un bloc de branche dans un ECG ?

    Un bloc de branche se manifeste par des complexes QRS élargis supérieurs à 120 millisecondes et présente des schémas particuliers selon qu'il s'agit d'un bloc de branche gauche ou droit.

  • Comment identifier un bloc AV du premier degré ?

    Un bloc AV du premier degré est identifié par un allongement de l'intervalle PR au-delà de 200 millisecondes.

  • Que sont les contractions prématurées ?

    Les contractions prématurées, comme les contractions ventriculaires prématurées (PVC), apparaissent comme des battements complexes larges et sont généralement bénignes.

  • Qu'est-ce que la tachycardie ventriculaire ?

    La tachycardie ventriculaire est un type de tachycardie à large complexe régulier, pouvant menacer la vie si elle dégénère en fibrillation ventriculaire.

  • Comment l'élévation du segment ST se manifeste-t-elle ?

    L'élévation du segment ST apparaît comme une élévation du segment entre la fin de l'onde S et le début de l'onde T, souvent associée à un infarctus du myocarde.

  • Quels sont les rythmes de l'arrêt cardiaque ?

    Les rythmes de l'arrêt cardiaque incluent la tachycardie ventriculaire, la fibrillation ventriculaire, l'activité électrique sans pouls et l'asystolie.

  • Qu'est-ce que l'activité électrique sans pouls ?

    L'activité électrique sans pouls est un rythme non chocable où il y a une activité électrique mais pas de pouls.

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  • 00:00:00
    foreign
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    [Music]
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    we will look at some of the most common
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    and must-know ECG findings in medicine
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    we start with sinus rhythm the normal
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    Rhythm of the heart in this instance
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    there are regular p waves followed by a
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    QRS complex that represents normal
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    conduction of the electrical signals
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    from the sinoatrial node in the right
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    atrium through the atrioventricular node
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    and bundle of hiss into the ventricles
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    the PR interval which is the time
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    between the start of the P wave and
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    initiation of the QRS remains constant
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    throughout
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    the QRS complex itself represents
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    ventricular depolarization and is
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    normally narrow typically between 80 and
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    100 milliseconds
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    in adults if the rate is below 60 beats
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    per minute this is sinus bradycardia and
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    above 100 beats per minute is sinus
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    tachycardia
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    next we have atrial fibrillation in this
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    case there is abnormal electrical
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    activity that leads to the atrial muscle
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    fibers Contracting at different times it
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    is these uncoordinated contractions that
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    give the quivering or fibrillating
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    activity
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    the ECG therefore has no clear p waves
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    with QRS complexes not being preceded by
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    a P wave although the fibrillations can
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    somewhat resemble a P wave at times they
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    will not be consistent only some of the
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    electrical signals get conducted down
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    into the ventricles and therefore lead
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    to ventricular depolarization but
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    there's no real pattern of which
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    impulses will get conducted therefore we
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    end up with the textbook irregularly
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    irregular heart rhythm this is described
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    as a variable interval between the r
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    waves on the ECG
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    generally it occurs as a result of a
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    substrate that will maintain the
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    arrhythmia such as dilatation of the
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    Atria and a triggering event such as
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    electrical activity arising from another
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    atrial location most commonly this is in
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    the region of the pulmonary veins rates
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    above 100 beats per minute are known as
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    atrial fibrillation with rapid
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    ventricular response while those under
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    60 beats per minute are atrial
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    fibrillation with slow ventricular
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    response I have a video dedicated to
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    atrial fibrillation and will leave a
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    link to it atrial flutter is often
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    mistaken for atrial fibrillation they
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    are similar the main difference is that
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    atrial flutter features coordinated
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    electrical activity in the Atria due to
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    a re-entry circuit leading to Rapid
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    contraction of the Atria this is usually
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    around 300 beats per minute with a
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    regular atrial rate and narrow complex
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    tachycardia as a useful side note
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    supraventricular tachycardia is an
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    umbrella term to describe tachyarhmias
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    With An Origin above the ventricles
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    that's a classically described as narrow
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    complex tachycardias examples include
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    sinus and atrial tachycardia as well as
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    atrial fibrillation with rapid
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    ventricular response and atrial flutter
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    amongst others the ECG in atrial flutter
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    classically shows a Sawtooth pattern
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    coming from inverted P waves usually in
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    the inferior leads it is also described
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    looking at the number of p waves
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    compared to the number of ventricular
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    contractions showing the ratio of
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    non-conducted to conducted beats most
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    commonly this is two to one giving a
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    ventricular rate around 150 beats per
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    minute and higher ratios indicate a
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    higher degree of block through the
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    atrioventricular node the term block
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    here is not the same as the AV blocks
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    that are coming up it is worth noting
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    that the conduction ratio of one to one
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    is possible and is highly associated
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    with instability and progression to
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    ventricular fibrillation
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    these ratios can be variable in the same
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    patient making the ventricular rate
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    irregular which is why it can often be
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    mistaken for atrial fibrillation now we
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    have premature contractions which are
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    extremely common findings on ECGs
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    premature ventricular contractions or
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    PVCs are Beats that originate from the
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    histor kinji region of the conduction
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    system and therefore appear as wide
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    complex beats above 120 milliseconds in
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    duration there is then a compensatory
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    pause before the next beat although can
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    be felt as palpitations they are rarely
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    dangerous alone unless they are frequent
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    defined as over 10 to 30 per hour and if
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    happening every other beat are described
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    as by Gemini while having a sequence of
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    PVCs one after the other may be
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    described as ventricular tachycardia
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    which we'll cover later on premature
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    atrial contractions or Pacs are seen as
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    a P wave with a different morphology to
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    the regular sinus p waves followed then
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    by a narrow QRS complex the beat
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    following the PAC May resemble a pause
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    however if you track out the expected
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    location of the P wave it should fall at
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    approximately the expected time Pacs do
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    not typically require further
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    investigation
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    bundle branch blocks are another feature
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    that are fairly common in general these
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    are described as left or right bundle
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    branch blocks it's worth knowing as well
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    that the left bundle branch splits again
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    into the anterior and posterior branches
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    these patterns feature wide QRS
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    complexes Beyond 120 milliseconds
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    left bundle branch blocks feature a deep
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    S Wave in V1 and prolonged R wave in V6
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    giving a w and m shape respectively
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    while right bundle branch blocks have an
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    rsr wave pattern in V1 and prolonged S
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    Wave in V6 giving M and W shapes
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    respectively an easy way to remember
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    this is with the mnemonic William marrow
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    also remember that the ST segment is
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    affected in bundle branch blocks and so
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    interpreting St changes is challenging
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    and needs specific criteria
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    now let's take a look at the
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    atrioventricular or AV blocks first
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    degree AV block is due to slowed
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    conduction through the AV node shown by
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    a prolongation of the PR interval Beyond
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    200 milliseconds
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    in general this is a fairly benign
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    finding but can in some instances
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    progress to higher degree blocks second
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    degree AV block has two main types
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    called mobit 1 or wenkebach and mobitz 2
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    or hey mobit 1 features a progressive
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    lengthening of the PR interval until
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    there is a non-conducted P wave then the
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    cycle repeats mobits 2 features a
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    non-conducted P wave with no variation
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    in the PR interval type 2 is usually due
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    to a structural abnormality and is
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    considered high risk for progression to
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    third degree also known as complete
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    heart block in third degree AV block
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    there is no association between atrial
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    and ventricular contractions on the ECG
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    this appears as p waves that do not lead
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    to a QRS complex and more p waves than
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    QRS complexes indicating a higher atrial
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    rate than ventricular rate which is most
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    commonly severely bradycardic typically
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    there are regular POS waves and regular
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    QRS complexes but no association between
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    the two with the QRS complexes being
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    generated by junctional or Escape
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    rhythms I also have a video dedicated to
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    Heart blocks that are link here
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    next we have ventricular tachycardia and
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    ventricular fibrillation which are two
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    crucial ECGs to recognize ventricular
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    tachycardia is defined as a broad
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    complex regular tachycardia the main
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    type being monomorphic ventricular
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    tachycardia where there is a single
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    source for the beets and so the QRS
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    complexes in one lead all look the same
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    polymorphic VT is the term used when
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    there is more than one source of the
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    ventricular beats and so gives varying
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    morphologies of the QRS complexes one
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    famous example of polymorphic VT is
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    torsades the points occurring in the
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    setting of a prolonged QT interval
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    although other causes for regular broad
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    complex tachycardia exist it isn't
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    straightforward to distinguish them and
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    generally if there is any diagnostic
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    uncertainty it is treated as ventricular
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    tachycardia some features suggesting VT
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    include very broad complexes above 160
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    milliseconds absence of bundle branch
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    block morphologies and the presence of
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    extreme axis deviation ventricular
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    tachycardia itself can result in Cardiac
  • 00:09:32
    Arrest but may also degenerate
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    interventricular fibrillation which is a
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    lethal Rhythm if not treated there are
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    no clear p waves or QRS complexes and
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    therefore minimal cardiac output
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    the ECG features chaotic electrical
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    activity of varying amplitudes with the
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    amplitude correlating to duration as
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    time goes on it reduces until asystole
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    is reached these two arrhythmias are
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    associated with Cardiac Arrest defined
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    as cessation of normal blood circulation
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    due to failure of the heart to pump
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    blood and are the two shockable rhythms
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    in Cardiac Arrest The non-shockable
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    rhythms being pulseless electrical
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    activity and asystole
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    number 10 is one of the most famous ECG
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    abnormalities St elevation although not
  • 00:10:25
    in arrhythmia it is an important ECG
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    feature on the ECG this is the portion
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    between the end of the S Wave and the
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    beginning of the T wave acute myocardial
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    infarction is largely the most
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    significant cause however there can be
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    many other causes too including
  • 00:10:44
    pericarditis left bundle branch block
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    left ventricular hypertrophy and even a
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    normal finding such as in benign early
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    repolarization
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    typically the elevation is defined as
  • 00:10:58
    more than one millimeter from the
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    isoelectric Baseline in any lead apart
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    from Leeds V2 and V3 that generally
  • 00:11:07
    require at least 1.5 millimeters also
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    remember that different leads represent
  • 00:11:13
    different territories of the heart
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    leads 1 AVL V5 and V6 are lateral leads
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    2 3 and avf are inferior well V1 to V4
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    are anterior and septal for a posterior
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    view additional chest leads V7 to v9 are
  • 00:11:33
    needed in stemi you expect the elevation
  • 00:11:36
    to be present in territories that are
  • 00:11:38
    affected by the blocked coronary artery
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    and St depressions in opposite
  • 00:11:43
    territories termed reciprocal changes
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    which is why if St depressions are seen
  • 00:11:49
    in the anterior leads an ECG with leads
  • 00:11:52
    V7 to v9 should be done which may reveal
  • 00:11:56
    posterior stemi check out my video
  • 00:11:59
    specifically on ECG interpretation and I
  • 00:12:03
    recommend sources like Life in the Fast
  • 00:12:05
    Lane and ECG waves for further reading
  • 00:12:08
    which are the main references for this
  • 00:12:10
    video
Tags
  • ECG
  • rythme cardiaque
  • fibrillation auriculaire
  • tachycardie
  • bloc AV
  • contractions prématurées
  • flutter auriculaire
  • infarctus du myocarde
  • fibrillation ventriculaire
  • électrocardiogramme