Chamber Enlargement

    .

     

    Atrial Abnormality

    • Word "Enlargement" is no longer preferred.  Please use "Abnormality".
    •   Right Atrial Abnormality (RAA) Left Atrial Abnormality (LAA)
      Causes
      • Congenital
      • Valvular Heart Disease
      • Cor pulmonale
      • Mitral Stenosis
      • Mitral Regurgitation
      • Hypertension
      • Ischemic Heart Disease

       

      Criteria

       

      Right Atrial Hypertrophy/Enlargement 

       INCREASES the height of the P-wave. 

       

      P-Wave Criteria: 

        1.  P wave > 2.5mm in height (Lead II)

        2.  Positive first part of P-wave in V1 > 1.5mm

        3.  P-wave Axis:

                - Rightward--> P pulmonale

                - Leftward --> P congenitale

       

      LAA: Because the LA depolarizes after the RA, delay in 

      the LA depolarization PROLOGUES the duration of the

      P-wave. (and negative component of P-wave in V1)

       

       

      Following Criteria are popular (each independently)

      1.  Morris Index - Negative part of P-wave in V1

           duration (ms) x depth (mm) larger than -40ms

       

      P-wave LAE Morris Index.jpg

       
       
       

       

       

      2.  P-wave Duration ≥ 0.12s (leads I, II, III) +

          negativity in V1 > 40ms

       

      (Negative phase of P in V1 > 0.04s

       --> MOST SENSITIVE Sn=83%, Sp=80%))

       

      Wide notched P wave (aka intra-atrial block),
        + interpeak interval >0.04s
      (MOST SPECIFIC, Sn=15%, Sp=100%)

       

      3.  P-wave Duration >120ms, and widely notched P-wave (>40ms)

        P-wave1.jpg
       

      Source: 

      1.  Hancock et al (2009) "Part V: Electrocardiogram Changes Associated With Cardiac Chamber Hypertrophy" AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the ECG

       

      2.  Bayes de Luna (2014) "ECGS for Beginners" Published by Wiley Blackwell

       

     

     

    Ventricular Enlargements

      RV Enlargement LV Enlargement
    Causes

    Congenital Cardiomyopathies

    Right Valvular Heart Diseases

    Cor Pulmonale

    Acquired (Aortic Valve Disease, Hypertension)

    Cardiomyopathies (Ischemic CMP, Genetic CMP)

    Congenital Heart Disease (AS, Coarctation, fibroelastosis)

    Description

    Direction of forces changed to 

    the right (sometimes forward or backwards)

    Manifests as larger R-wave and smaller S-wave in V1

    and larger S-wave and smaller R-wave in V6.

    The free wall typically grows the most, which directs more 

    forces backwards, upwards, and left.  (Leftward Axis)

    Criteria:

     

    (most common criteria - the more criteria,

         the more likely the dx):

    1. QRS Axis ≥ 110° (S>R height in I)

    2. V1 => R>S in height (R/S > 1)

         and/or S in V1 < 2mm

         and/or R ≥ 7mm

    3. V6 => S>R in amplitude (R/S ≤ 1)

         and/or S in V5-V6 > 7mm

    4. P-wave of RAE

     

    NOTE: rSr' in V1 requires a differential diagnosis

     (If QS morphology in V1 with S in V6, R-axis, RAE

      would suggest RVE to be the cause of rSr'). 

     

    Associated with RVE (Support diagnosis)

    - RBBB

    - Repolarization Abnormalities (ST depressions, TWI)

    Cornell Criteria:

    - R in aVL + S in V3 > 24mm in men, > 20mm in women

    (Sensitivity: 22%, Specificity: 100%)

     

     

    Sokolow-Lyon Criteria: 

    - S in V1 + R in V5-6 ≥ 35mm

    (Sensitivity: 42%  Specificity: 96%)

     

     

    Sokolow Index (aka "aVL Criteria")

    aVL ≥ 11mm

    controversial in the presence of left anterior fascicular block

    - Some say use a cutoff of ≥16, but recent study by Ravi 2013 

    indicates criteria maintains specificity in LAFB.

    (Sensitivity: 9-13%, Specificity 99%)

     

    Diagnosing Scoring Systems: (rarely used in practice)

    i.e. Estes Score (scores ST changes, voltage criteria, 

    and negative P-waves) and calculates probability of LVH

     

    Associated:

    - Repolarization changes (ST depression, TWI)

     (i.e. strain pattern)

    - AFib

    - LAE

    LVH in setting of BBB

    • Intraventricular conduction delays (including RBBB and LBBB) can alter the voltages+axis, and impact our ability to diagnose LVH. 
    • Summary

      • ​​​LVH Criteria remain specific, but lose sensitivity! (false negatives)

       

      • LVH is likely if criteria are met; however, absence of criteria does not rule out LVH. 
      • The only exception is Sokolow-Lyon Criteria, which has almost no clinical utility in LBBB

     

    • Evidence:
      • Many studies have looked into the ability of voltage criteria to predict LVH in the setting of BBB. 
    • Name Criteria Normal Conduction LBBB RBBB
        SV3 ≥ 25mm   Sn 47% Sp 93%  
        RV5 or RV6 ≥ 25 Sn 25% Sn 0-8% Sn 9-14% Sp > 90%
      Sokolow-Lyon Criteria SV1 + RV5 or V6 ≥ 35mm Sn 42% Sp 96% Sn 37-50% Sp 50-73% Sn 2-6%  Sp 90-100%

      Modified Sokolow-Lyon

      to improve specificity

      SV1 + RV5 or V6 ≥ 45mm Sn 34% Sn 45%  Sp 91% Sn 0%  Sp ???
      Cornell Criteria SV3 + RaVL ≥ 30mm Sn 22% Sp 100% Sn 66% Sp >90% Sn ??% Sp > 90%

      Sokolow Index

      (aka "aVL criteria)

      RaVL ≥ 11 (or >12) Sn 9-13% Sp 99% Sn 24% Sp > 89% Sn 27-29% Sp > 86-90%
        RI +SIII ≥ 25 (or >25) Sn 11% Sn 13% Sp > 98% Sn 23-27% Sp > 90%
        L Atrial Abnormality Sn 47% Sp 91% Sn 41-86% Sp >90% Sn 58-75% Sp 82-91%
    • In presence of LBBB
      • V5/V6 voltages in isolation are not useful.
      • Sokolow-Lyon Criteria loses specificity (still reasonable sensitivity)  
      • Sokolow (SV1+RV5 or RV6 ≥ 35mm) and Cornell (SV3 + RaVL ≥ 30mm) are best for ruling out 
    • In presence of RBBB
      • All criteria remain very specific
      • All criteria lose sensitivity, especially:
        • Criteria involving R-precordial leads (i.e. V1-V2, such as Sokolow criteria) have virtually no sensitivity (but keep their specificity)
        • Sensitivity in limb leads seems to be better.
    • References:
      • Vandenberg B et al (1991) "Electrocardiographic diagnosis of LVH in the presence of bundle branch block" 122(3), 818-822
      • Kafka et al (1985) "Hypertrophy in the presence of LBBB: An echocardiographic Study" Am J Cardiol 103-106

    LVH in setting of LAFB

    • AHA/ACCF/HRS published joint recommendations for Standardization and Interpretation of the Electrocardiogram in 2009:
      • "In left anterior fascicular block, the QRS ventor shits in a posterior and superior direction, resulting in larger R-waves in leads I and aVL, and smaller R-waves but deeper S-waves in leads V5 and V6. R-wave amplitude in leads I and aVL are not reliable criteria for LVH in this situation"
      • In Summary: Using leads I and aVL is not recommended for diagnosing LVH in setting of LAFB
    • Since then, in 2013: a study by Ravi et al analyzing 185 LAFB ECGs with echo studies demonstrated:
      • Criteria Sensitivity Specificity
        Sokolow Index (RaVL ≥ 11) 32% 91%
        Cornell Criteria (SV3 + RaVL ≥ 30mm) 44% 84%
    • Therefore: Although not recommended by AHA/ACCF/HRS joint statement, newer higher quality evidence shows aVL criteria (Sokolow Index and Cornell Criteria) can be useful in the setting of LAFB.
    • References:
      • Hancock et al (2009) "AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram" Journal of the American College of Cardiology53(11):993-1002
      • Ravi et al (2013) Ann Noninvasive Electrocardiol 18(1):21-28
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