II. Causes: Non-Cardiac Causes
- Lack of sleep
- Volume depletion
- Caffeine Intake
- Emotional stress
- Anemia
- Illicit Drug Use
- Viral illness
- Personality Disorder
III. Causes: Cardiac Dysrhthmia types
- Conduction defects- Underlying Coronary Artery Disease (over age 40)
- Manifested with rising level of ischemia
 
- Enhanced automaticity- Sympathetic load
- Increased Afterload stimulates stretch receptors
- Irritability of pacers due to ischemia
 
- Re-entry phenomena: Accessory bundles- Wolff-Parkinson-White Syndrome
- Long-Ganong-Levine Syndrome
 
- Re-vascularization- Post thrombolsis
- Post arteriospasm
 
IV. Symptoms: Red Flags
- Decreased Cardiac Output
- Wall motion abnormality- Awareness of heart beat
- Palpitations
 
V. Signs: Red Flags
- Resting Tachycardia
- Hypertension
- Chest deformity (e.g. Pectus Excavatum)
- Suspicious cardiac murmur
VI. Diagnostics: Normal EKG Findings in Athletes
- See Athletic Heart Syndrome
- 
                          Sinus Bradycardia (30 to 60 bpm)- May occur with or without sinus Arrhythmia
- Associated with high Resting Vagal Tone
- Electrocardiogram changes resolve when exercising
 
- Other normal atrial Arrhythmias associated with high vagal tone in asymptomatic athletes- Sinus Arrhythmia
- Ectopic atrial rhythm (PACs)
- Junctional escape rhythm
- First Degree Atrioventricular Block (PR Segment 200 to 400 ms)- Athletes: 10-33% Incidence
- General population: 0.65% Incidence
- PR Segment >400 ms is considered abnormal
 
- Second Degree Atrioventricular Block - Mobitz 1 (Wenckebach)
 
- Increased QRS Complex height (High Voltage criteria)- Criteria
- Associated findings in which LVH and RVH are pathologic in athletes- Inferior or lateral lead T Wave Inversion
- ST segment Depression
- Pathologic Q Waves
- Left atrial enlargement
- Left Axis Deviation
 
 
- 
                          Early Repolarization
                          - Common finding in young healthy males- Athletes (up to 90% Prevalence)
- Black patients
 
- Criteria- J Point Elevation >0.1 mV (at the QRS-ST Junction) in 2 or more anterolateral leads
- QRS Slurring (with or without J Waves) may also be present
- Concave upward ST Segment is common
 
- Interpretation- Early Repolarization is a normal, benign finding in asymptomatic athletes
- Black athletes may also have a Benign Early Repolarization variant- Anterior lead (V1-V4) J Point Elevation
- May be associated with convex ST Elevation, and followed by an inverted T Wave
 
 
- Precautions: Factors that may be associated with ventricular Arrhythmias and sudden death- Inferolateral J Waves (esp. >0.2 mV, inferior leads)
- Family History of Sudden Death
 
 
- Common finding in young healthy males
- Other Ventricular Findings in asymptomatic athletes- Juvenile T Wave Pattern (teen athletes)- Anterior T Wave Inversion in leads V1-V4 is normal in age <16 years
 
- Incomplete Right Bundle Branch Block
 
- Juvenile T Wave Pattern (teen athletes)
VII. Diagnostics: Borderline EKG Findings in Athletes
- Borderline EKG Findings- Axis Deviation
- Atrial Enlargement
- Complete Right Bundle Branch Block- PrevalenceGeneral Population: 1%
- Prevalence Young Athletes: 2.5%
 
 
- Interpretation- Single isolated borderline findings do NOT require additional evaluation
- Multiple borderline findings (or in symptomatic athletes) should be referred to cardiology
 
VIII. Diagnostics: Abnormal EKG Findings in Athletes
- See Sudden Death in Athletes
- Abnormal findings suggesting Cardiomyopathy- T Wave Inversion >=1 mm in 2 or more contiguous leads- Includes leads V2-6, II and avF or I and avL
- Exceptions- NOT pathologic in leads III, aVR or V1
- NOT pathologic in juvenile T Wave pattern
- NOT pathologic in black athletes with Early Repolarization variant in anterior leads
 
- Interpretation- Inferior and lateral T Wave Inversion is associated with Hypertrophic Cardiomyopathy
- Anterior T Wave Inversion is associated with Arrhythmogenic Right Ventricular Cardiomyopathy (ARVD)
 
- Evaluation- Echocardiogram
- Cardiac MRI
- Exercise Stress Test
- Continuous ECG Monitor (24 hours minimum)
- Annual follow-up if initial evaluation negative
 
 
- ST segment Depression >0.5mm in 2 or more leads- Obtain Echocardiogram
- Consider Cardiac MRI if Echocardiogram abnormal
 
- Pathologic Q Waves >3 mm or >40 ms in two or more leads (except III and aVR)- False PositiveQ Waves
- Associated Conditions
- Evaluation
 
- Complete Left Bundle Branch Block- Considered pathologic in most cases (rare finding in athletes)
- Evaluation- Echocardiogram
- Cardiac MRI with perfusion
 
 
- Other Cardiomyopathy findings- Wide QRS >140 ms duration
- Left Axis Deviation
- Left atrial enlargement
- Right Ventricular Hypertrophy (benign if isolated finding)
 
 
- T Wave Inversion >=1 mm in 2 or more contiguous leads
- Abnormal findings suggesting life threatening Arrhythmia risk- QT Prolongation- See QT Prolongation
- QTc Interval >500 ms
- Associated with Torsades de Pointes and Sudden Cardiac Death in age <40 years
- Evaluation (for QTc Interval >470 ms in males, >480 ms in females)- Cardiology referral
- Obtain a thorough Family History (e.g. congenital QTc Prolongation)
- Obtain a medication history
 
 
- Brugada Syndrome- Right bundle branch with ST Elevation in the anterior leads
- Refer to cardiology for diagnosis confirmation and management (e.g. AICD placement)
 
- WPW Syndrome (ventricular preexcitation)- WPW Prevalence: 0.4% of athletes (1 in 250)
- Findings- Short PR Interval AND Delta wave at QRS suggests accessory pathway
- Short PR Segments WITHOUT Delta in asymptomatic athletes are common and benign
 
- Evaluation- See WPW Syndrome
- Cardiology referral
- Echocardiogram
- Exercise Stress Test
 
 
- High Grade Atrioventricular Block- Second Degree Atrioventricular Block - Mobitz 2 (High grade AV Block)
- Third degres AV Block (may present as Syncope)- May be associated with underlying Coronary Artery Disease
 
 
 
- QT Prolongation
- Other abnormal findings- Severe Sinus Bradycardia (<30 bpm)
- PR Interval >400 ms
- Ventricular Arrhythmias
- Atrial tachyarrhythmias (e.g. Atrial Fibrillation or Atrial Flutter)
 
IX. References
- Annous, Kiel and Drezner (2024) Crit Dec Emerg Med 38(8): 4-11
- Drezner (2013) Br J Sports Med 47:122–4 [PubMed]
