II. Signs: Unstable

III. Differential Diagnosis

  1. Pulseless Electrical Activity
  2. Narrow Complex Tachycardia
    1. Sinus Tachycardia
    2. Irregular Supraventicular Tachycardia
      1. Atrial Fibrillation
    3. Regular Supraventricular Tachycardia
      1. Sinus Tachycardia (rarely >150 in adults)
      2. Atrial Flutter
        1. Atrial rate: 300 bpm
        2. Ventricular rate most commonly 2:1 = 150 bpm
      3. Paroxysmal Supraventricular Tachycardia (PSVT)
        1. Atrioventricular Nodal Reentry (AVNRT)
          1. Signal down the slow AV nodal pathway and retrograde up the fast AV nodal pathway
          2. In 10% of cases, the signal reentry route is reversed
        2. Atrioventricular Reciprocating Tachycardia (AVRT)
          1. Includes Wolff-Parkinson-White Syndrome (characterized by delta wave)
          2. Accessory pathway outside the AV Node
            1. Orthodromic (narrow complex): Signal down the AV Node and up the accessory path
            2. Antidromic (wide complex): Signal down the accessory path and up the AV Node
        3. Atrial Tachycardia (AT)
          1. Abnormal focus of atrial automaticity (outside the SA Node)
          2. Unlike AVNRT and AVRT, no accessory pathway is involved
        4. Junctional Ectopic Tachycardia
  3. Wide Complex Tachycardia
    1. Ventricular Tachycardia (VT)
    2. Torsade De Pointes
    3. Supraventricular Tachycardia (SVT) with aberrancy (e.g. Bundle Branch Block)
      1. Mistakenly managing Ventricular Tachycardia as SVT can be lethal (assume VT first)
        1. Even using established guidelines for wide SVT, will miss 10-40% of cases
      2. Findings consistent with Ventricular Tachycardia
        1. Lead V1 with taller R than R' (taller left rabbit ear)
        2. Lead V6 with R Wave < S Wave (RS upward deflection < downward deflection)
        3. Atrioventricular Dissociation
        4. Fusion complexes (Fusion Beats)
          1. Combined supraventricular and ventricular beats (e.g. QRS Complex merges into P Wave)
      3. References
        1. Mattu (2018) Crit Dec Emerg Med 32(5): 29

IV. Management (Same initial approach for all ages)

  1. ABC Management
  2. Mnemonic: IV-O2-Monitor
    1. Obtain IV Access
    2. Oxygen Delivery
    3. Cardiopulmonary monitor
  3. Additional evaluation
    1. Vital Signs
    2. History
    3. Exam
    4. Electrocardiogram
    5. Chest XRay
  4. If signs of immediate failure present:
    1. Pulse Present and NOT Sinus Tachycardia
      1. Prepare for immediate Synchronized Cardioversion
      2. Brief trial of medications (e.g. Adenosine) if no delay
    2. Pulse Absent
      1. Asystole
      2. Pulseless Electrical Activity
      3. Ventricular Tachycardia
      4. Ventricular Fibrillation
  5. Assess QRS Duration
    1. If QRS Duration narrow (<0.09 sec in children or <0.12 sec in adults)
      1. See Narrow Complex Tachycardia
      2. See Supraventricular Tachycardia Management in the Child
      3. See Supraventricular Tachycardia Management in the Adult
    2. If QRS Duration wide (>0.09 sec in children or >0.12 sec in adults)
      1. See Wide Complex Tachycardia
      2. See Ventricular Tachycardia Management in the Adult
      3. See Ventricular Tachycardia Management in the Child

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Related Studies

Ontology: Tachycardia (C0039231)

Definition (NCI_NCI-GLOSS) Rapid beating of the heart, usually defined as greater than 100 beats per minute.
Definition (NCI) An abnormally rapid heart rate. Thresholds for different age, gender, and patient populations exist.
Definition (CSP) excessive rapidity in the action of the heart.
Definition (MSH) Abnormally rapid heartbeat, usually with a HEART RATE above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia.
Concepts Sign or Symptom (T184)
MSH D013610
ICD9 785.0
ICD10 R00.0
SnomedCT 207003004, 86651002, 6285003, 3424008
LNC LA17714-9
English Tachycardias, PULSE RATE INCREASED, Tachycardia, unspecified, [D]Tachycardia, unspecified (context-dependent category), [D]Rapid heart beat, [D]Tachycardia, unspecified, Increased pulse rate, tachycardia, tachycardia (by pulse measurement), tachycardia by pulse, tachycardia by pulse (physical finding), tachycardia (diagnosis), fast heart rate, fast heart rate (symptom), a tachycardic pulse was noted, Heart rate high, Heart rate increased, Heartbeats increased, High pulse rate, Pulse increased, Pulse rate increased, Quick pulse, Tachycardia NOS, Tachycardia [Disease/Finding], increased heart rate, increased pulse rate, Heartbeat (pulse);fast, high pulse rate, rapid heart rate, rapid pulse, rapid heart beat, fast pulse, rapid heartbeat, [D]Tachycardia, unspecified (situation), Pulse rapid, TACHYCARDIA, HEART RATE, INCREASED, INCREASED HEART RATE, Pulse fast, Rapid pulse, Tachycardia - pulse, Pulse fast (finding), Rapid heart beat, Heart rate fast, Increased heart rate, heart beat; rapid, heart; frequency high, rapid; heart beat, rapid; heart, Tachycardia, Tachycardia, NOS, Tachycardia (finding), Rapid Heart Rate, fast heartbeat, Heartbeat (pulse);rapid
French TACHYCARDIE, Pouls rapide, Tachycardie SAI, Tachycardie, non précisée, Fréquence cardiaque élevée, Pouls augmenté, ACCELERATION DU POULS, Rapidité du pouls, Pouls accéléré, Battements cardiaques accélérés, Fréquence cardiaque augmentée, Tachycardie
Portuguese TAQUICARDIA, Frequência do pulso elevada, Taquicardia NE, Frequência cardíaca alta, Pulso aumentado, Pulso rápido, Frequência do pulso aumentada, FREQUENCIA DO PULSO AUMENTADA, Frequência cardíaca aumentada, Taquicardia
Spanish TAQUICARDIA, Pulso rápido, Pulso aumentado, Frecuencia del pulso aumentada, Latidos cardiacos aumentados, Frecuencia cardiaca alta, Taquicardia no especificada, Frecuencia de pulso alta, Taquicardia NEOM, [D]taquicardia no especificada (categoría dependiente del contexto), PULSO, FRECUENCIA AUMENTADA, [D]frecuencia cardíaca rápida, [D]taquicardia no especificada (situación), [D]taquicardia no especificada, frecuencia cardíaca aumentada, frecuencia del pulso aumentada (hallazgo), frecuencia del pulso aumentada, frecuencia del pulso incrementada, latidos cardíacos rápidos, taquicardia (hallazgo), taquicardia, taquisfigmia, Frecuencia cardiaca aumentada, Taquicardia
German TACHYKARDIE, Pulsfrequenz erhoeht, Herzschlaege erhoeht, Puls schnell, Tachykardie, unspezifisch, hohe Pulsfrequenz, Puls erhoeht, Herzfrequenz hoch, Tachykardie NNB, schneller Puls, PULSFREQUENZANSTIEG, Tachykardie, nicht naeher bezeichnet, Herzfrequenz erhoeht, Tachykardie
Italian Frequenza cardiaca aumentata, Polso rapido, Frequenza cardiaca elevata, Battiti cardiaci aumentati, Frequenza del polso aumentata, Tachicardia NAS, Polso veloce, Tachicardia non specificata, Polso aumentato, Frequenza del polso elevata, Tachicardia
Dutch hoge polsfrequentie, tachycardie NAO, hartfrequentie hoog, pols verhoogd, snelle pols, pols snel, hartslagen verhoogd, polsfrequentie verhoogd, tachycardie, niet-gespecificeerd, hart; frequentie hoog, hartslag; snel, snel; hartslag, snel; hart, Tachycardie, niet gespecificeerd, hartfrequentie verhoogd, tachycardie, Tachycardie
Japanese 頻脈, 頻脈NOS, 頻脈、詳細不明, 心拍数増加, 脈拍増加, 心拍増加, 脈拍数増加, ヒンミャクショウサイフメイ, シンパクゾウカ, ミャクハクスウゾウカ, シンパクスウゾウカ, ヒンミャク, ミャクハクゾウカ, ヒンミャクNOS, 脈拍数高値, シンパクスウコウチ, 心拍数高値, ミャクハクスウコウチ
Swedish Takykardi
Czech tachykardie, Tachykardie NOS, Srdeční frekvence zvýšená, Pulz zvýšený, Tachykardie, Zrychlený tep srdce, Tachykardie, blíže neurčená, Pulz rychlý, Rychlý pulz, Vysoká srdeční frekvence, Vysoká pulzová frekvence, Pulzová frekvence zvýšená
Finnish Takykardia
Korean 상세불명의 빠른맥
Polish Częstoskurcz, Tachykardia
Hungarian Szívverés fokozott, Pulzusszám magas, Pulzus gyors, Tachycardia k.m.n., Pulzus emelkedett, Szívfrekvencia emelkedett, Gyors pulzus, Tachycardia, nem meghatározott, Tachycardia, Szívfrekvencia magas, Pulzus frekvencia emelkedett
Norwegian Takykardi

Ontology: Tachyarrhythmia (C0080203)

Definition (NCI_NICHD) Tachyarrhythmia is any disturbance of the heart rhythm in which the heart rate is abnormally increased.
Definition (NCI) A disorder characterized by an arrhythmia with an above normal rate.
Concepts Finding (T033)
MSH D013610
SnomedCT 6285003
English Tachyarrhythmias, tachyrhythmia, rapid and irregular heartbeat, tachyarrhythmia, tachyarrhythmias, Tachyarrhythmia, Tachyarrhythmia (disorder), Tachyarrhythmia, NOS
Japanese 頻脈性不整脈, ヒンミャクセイフセイミャク
Portuguese Taquiarritmia
Spanish Taquiarritmia, taquiarritmia (trastorno), taquiarritmia
French Tachyarythmie, Tachy-arythmie
German Tachyarrythmie, Tachyarrhythmia
Czech Tachyarytmie, tachyarytmie
Hungarian Tachyarrhythmia
Norwegian Takyarytmi
Italian Tachiaritmia
Dutch tachyaritmie, Tachyaritmie