Athletic Heart Syndrome

Aka: Athletic Heart Syndrome, Normal Electrocardiogram Changes in Athletes, EKG Changes in Athletes

advertisement

II. Physiology

  1. Regular intensive Exercise results in normal reversible heart adaptations with cardiac remodeling
  2. Ventricular hypertrophy (increases in Muscle mass, wall thickness and chamber size)
    1. Most significant in strength trained athletes (e.g. weight lifting)
    2. Athletic ventricular hypertrophy is benign and reversible
  3. Increased vagal tone
    1. Sinus Bradycardia (>30 bpm) is normal (esp. in endurance athletes)
    2. Normal athletic Sinus Bradycardia should resolve with Exercise
    3. Early Repolarization is also related to increased vagal tone

III. Signs

  1. Increased Left Ventricular wall thickness by 15-20%
  2. Increased Left Ventricular End Diastolic Volume by 10%
  3. Resting Heart Rate: 30-60 bpm
  4. Irregular pulse
  5. Increased Pulse Pressure
  6. S3 Gallup at Apex (S4 Gallup should raise red flag)
  7. Physiologic split S2

IV. Imaging

  1. Chest XRay
    1. May show globular cardiomegaly
    2. Increased pulmonary vasculature
  2. Echocardiogram: Left Ventricular Dilatation (dynamic)
    1. Left Ventricular wall thickening (static)
    2. Normal Systolic and Diastolic function
  3. Stress Testing
    1. Athletes have an increased Incidence of False Positive stress tests

V. Diagnostics: Normal EKG Findings in Athletes

  1. See Athletic Heart Syndrome
  2. Sinus Bradycardia (30 to 60 bpm)
    1. May occur with or without sinus Arrhythmia
    2. Associated with high Resting Vagal Tone
    3. Electrocardiogram changes resolve when exercising
  3. Other normal atrial Arrhythmias associated with high vagal tone in asymptomatic athletes
    1. Sinus Arrhythmia
    2. Ectopic atrial rhythm (PACs)
    3. Junctional escape rhythm
    4. First Degree Atrioventricular Block (PR Segment 200 to 400 ms)
      1. Athletes: 10-33% Incidence
      2. General population: 0.65% Incidence
      3. PR Segment >400 ms is considered abnormal
    5. Second Degree Atrioventricular Block - Mobitz 1 (Wenckebach)
      1. Athletes: 10% Incidence
      2. General population: 0.003% Incidence
  4. Increased QRS Complex height (High Voltage criteria)
    1. Criteria
      1. Left Ventricular Hypertrophy (LVH)
      2. Right Ventricular Hypertrophy (RVH)
    2. Associated findings in which LVH and RVH are pathologic in athletes
      1. Inferior or lateral lead T Wave Inversion
      2. ST segment Depression
      3. Pathologic Q Waves
      4. Left atrial enlargement
      5. Left Axis Deviation
  5. Early Repolarization
    1. Common finding in young healthy males
      1. Athletes (up to 90% Prevalence)
      2. Black patients
    2. Criteria
      1. J Point Elevation >0.1 mV (at the QRS-ST Junction) in 2 or more anterolateral leads
      2. QRS Slurring (with or without J Waves) may also be present
      3. Concave upward ST Segment is common
    3. Interpretation
      1. Early Repolarization is a normal, benign finding in asymptomatic athletes
      2. Black athletes may also have a Benign Early Repolarization variant
        1. Anterior lead (V1-V4) J Point Elevation
        2. May be associated with convex ST Elevation, and followed by an inverted T Wave
    4. Precautions: Factors that may be associated with ventricular Arrhythmias and sudden death
      1. Inferolateral J Waves (esp. >0.2 mV, inferior leads)
      2. Family History of Sudden Death
  6. Other Ventricular Findings in asymptomatic athletes
    1. Juvenile T Wave Pattern (teen athletes)
      1. Anterior T Wave Inversion in leads V1-V4 is normal in age <16 years
    2. Incomplete Right Bundle Branch Block
      1. Athletes: 14% Incidence
      2. General athletes: 10% Incidence

VI. Diagnostics: Borderline EKG Findings in Athletes

  1. Borderline EKG Findings
    1. Axis Deviation
    2. Atrial Enlargement
    3. Complete Right Bundle Branch Block
      1. PrevalenceGeneral Population: 1%
      2. Prevalence Young Athletes: 2.5%
  2. Interpretation
    1. Single isolated borderline findings do NOT require additional evaluation
    2. Multiple borderline findings (or in symptomatic athletes) should be referred to cardiology

VII. Diagnostics: Abnormal EKG Findings in Athletes

  1. See Sudden Death in Athletes
  2. See Arrhythmias in Athletes
  3. Abnormal findings suggesting Cardiomyopathy
    1. T Wave Inversion >=1 mm in 2 or more contiguous leads
      1. Includes leads V2-6, II and avF or I and avL
      2. Exceptions
        1. NOT pathologic in leads III, aVR or V1
        2. NOT pathologic in juvenile T Wave pattern
        3. NOT pathologic in black athletes with Early Repolarization variant in anterior leads
      3. Interpretation
        1. Inferior and lateral T Wave Inversion is associated with Hypertrophic Cardiomyopathy
        2. Anterior T Wave Inversion is associated with Arrhythmogenic Right Ventricular Cardiomyopathy (ARVD)
      4. Evaluation
        1. Echocardiogram
        2. Cardiac MRI
        3. Exercise Stress Test
        4. Continuous ECG Monitor (24 hours minimum)
        5. Annual follow-up if initial evaluation negative
    2. ST segment Depression >0.5mm in 2 or more leads
      1. Obtain Echocardiogram
      2. Consider Cardiac MRI if Echocardiogram abnormal
    3. Pathologic Q Waves >3 mm or >40 ms in two or more leads (except III and aVR)
      1. False PositiveQ Waves
        1. High voltage criteria (Q/R ratio may be used to interpret Q Waves)
        2. Isolated Q Waves in V1 and V2 may be associated with high precordial lead placement
      2. Associated Conditions
        1. Hypertrophic Cardiomyopathy
        2. Arrhythmogenic Right Ventricular Cardiomyopathy (ARVD)
        3. Transmural Myocardial Infarction
      3. Evaluation
        1. Echocardiogram
        2. Exercise Stress Test
    4. Complete Left Bundle Branch Block
      1. Considered pathologic in most cases (rare finding in athletes)
      2. Evaluation
        1. Echocardiogram
        2. Cardiac MRI with perfusion
    5. Other Cardiomyopathy findings
      1. Wide QRS >140 ms duration
      2. Left Axis Deviation
      3. Left atrial enlargement
      4. Right Ventricular Hypertrophy (benign if isolated finding)
  4. Abnormal findings suggesting life threatening Arrhythmia risk
    1. QT Prolongation
      1. See QT Prolongation
      2. QTc Interval >500 ms
      3. Associated with Torsades de Pointes and Sudden Cardiac Death in age <40 years
      4. Evaluation (for QTc Interval >470 ms in males, >480 ms in females)
        1. Cardiology referral
        2. Obtain a thorough Family History (e.g. congenital QTc Prolongation)
        3. Obtain a medication history
          1. See Prolonged QT Interval due to Medication
    2. Brugada Syndrome
      1. Right bundle branch with ST Elevation in the anterior leads
      2. Refer to cardiology for diagnosis confirmation and management (e.g. AICD placement)
    3. WPW Syndrome (ventricular preexcitation)
      1. WPW Prevalence: 0.4% of athletes (1 in 250)
      2. Findings
        1. Short PR Interval AND Delta wave at QRS suggests accessory pathway
        2. Short PR Segments WITHOUT Delta in asymptomatic athletes are common and benign
      3. Evaluation
        1. See WPW Syndrome
        2. Cardiology referral
        3. Echocardiogram
        4. Exercise Stress Test
    4. High Grade Atrioventricular Block
      1. Second Degree Atrioventricular Block - Mobitz 2 (High grade AV Block)
      2. Third degres AV Block (may present as Syncope)
        1. May be associated with underlying Coronary Artery Disease
  5. Other abnormal findings
    1. Severe Sinus Bradycardia (<30 bpm)
    2. PR Interval >400 ms
    3. Ventricular Arrhythmias
    4. Atrial tachyarrhythmias (e.g. Atrial Fibrillation or Atrial Flutter)

VIII. References

  1. Annous, Kiel and Drezner (2024) Crit Dec Emerg Med 38(8): 4-11

Images: Related links to external sites (from Bing)

These images are a random sampling from a Bing search on the term "Athletic Heart Syndrome." Click on the image (or right click) to open the source website in a new browser window. Search Bing for all related images

Related Studies

Related Topics in Sports Medicine

advertisement