Cardiology in Sport Flashcards
Group 1 training related changes
- isolated voltage criteria for LVH (often normal size on echo)
- early repolarisation
- incomplete RBBB
- First degree AV block
- Sinus bradycardia
Which ECG leads represent the left ventricle?
leads v5 and v6
What is the general appearance of ECG waveforms in LVH?
Tall R in V5/6
Deep S in V1/2
What is the voltage criteria for LVH?
Sokolow-Lyon criteria:
S in V1/2
PLUS
R in V5/6 ≥35 mm (7 large squares)
OR
- total height of R waves is >5 large squares in V5/6
2 episodes of dizziness post-exercise in a competitive athlete- what does the ECG show and is it pathological?
- saddle shaped ST elevation leads 2,1 V3-6
- voltage criteria for LVH
This is normal- early repolarisation is normal in athletes
What does this ECG show and what does it mean in a young athlete?
biphasic T-wave inversion in lead 3
This is pathological even in an athlete and is not a sign of athletic adaptation
Black athlete, aSx
- prolonged PR interval (first degree heart block)
- voltage criteria for LVH (>5 squares in V5/6)
- early repolarisation in V2/3
- J point elevation
- T wave inversion V1-3
%black athletes with T wave inversion is quite high, especially in V1-4. So this is normal. If the T wave inversion was WIDESPREAD you’d be more suspicious of an inherited cardiomyopathy
Which ethnicity shows high rates of t-wave inversion?
Black athletes: Middle-west Africa and lesser extent Afro-caribbean
TWI in V1-4 present in 12-13% black athletes, usually preceded by ST elevation
When is TWI in black athletes abnormal?
- widespread
- TWI in inferior or lateral leads
Suggests cardiomyopathy eg hypertrophic cardiomyopathy
What does this ECG show and is it normal or abnormal?
R wave progression in lead 3
ST depression in lateral leads- this is ALWAYS PATHOLOGICAL
Widespread TWI
What is a pathogical Q wave?
associated with hypertrophic cardiomyopathy
ratio of Q wave to R wave- should be <1/4 of R wave
>0.4mV deep in any lead except 3 and aVR
15 y/o underwent pre-participation screening- what are the obvious abnormalities
- Very wide neck to T wave- unusual wave morphology
- QTc (QT interval corrected to HR) is prolonged
How is QT interval measured
Absolute QT interval is measured from the beginning of Q to end of T
QT is corrected for HR using the Bazett formula = QTc
Issue with Bazetts formula
- not good at tach/brady cardias
What is the criteria for QTc elongation in males and females
QTc> 440ms in males
QTc >460 in females
(each large square is 200ms 0.2s)
A lot of athletes have electrolyte imbalance, tired etc and goes below cut offs
What factors affect QTc?
- FHx
- U waves
- Subtle T-wave changes
- HR
- repolarisation abnormalities
- electrolytes: low K+, low Mg2+, low/high Ca2+
- Drugs
- Diurnal variations
problems with measuring QTc in athletes
- Slow HR
- Sinus arrhythmia
- Slightly wide QRS complexes
- T-U complexes
What is a common ECG finding in athletes that can lead to a falsely elongated QTc?
U waves are common in athletes
They precede T-waves and increase the measurement of the QTc
How to correctly measure QT interval
If you have any doubts from automatic reading you need to do this:
1) Use limb lead that best shows T wave- lead 5 or 2 usually
2) Beginning of QRS complex to end of T wave (work out like diagram)
3) average of 3-5 beats
4) Adjust for HR (measure during peak plasma conc if using QT prolonging medication)
What does this exercise stress test show? What are the chances of this being pathological
paradoxical prolongation of QTc- roughly >1/2 way between next R wave
increases 4 minutes into recovery
QTC>490 is basically diagnostic of long QT syndrome
What scoring system is used to determine the probability of long QT
Schwartz-score - <1 = low - 1.5-3 = intermediate - >3.5 = high difficult in athletes as lots have syncope, long QTC and resting bradycardia so often can be moderate but healthy
What was the issue with using the Schwartz-score in athletes? What alternative was devised?
up to 40% false positive in black athletes
Seattle criteria was then used as screening for athletes
What dos the following ECG show?
LAD
Lead 1 is up and 3 is down
What does the following ECG show?
Left axial enlargement
negative p wave in lead 1
Sign of left axial enlargement
negative p wave in V1
sign of right axial enlargement
Tall p waves in lead 2
Criteria for RVH
Sum of R in V1 + S in V5/6
> 10mm
opposite of LVH
When screening athletes for pathology, what steps are taken to eliminate false positives?
1) European Society of Cardiology guidelines, adjust for training related normal variants:
- sinus bradycardia
- first deg. AV block
- Incomplete RBBB
- Early repolarisation
- Isolated QRS voltage criteria for LVH
2) Refined Seattle criteria if not present in isolation
- left/right atrial enlargement
- LAD/RAD
- RVH
- TWI widespread
3) If 2 or more of refined criteria present:
- ST depression
- Path Q waves
- TWI beyond V4
- arrhythmia
aSx 15yr old athlete. What does this ECG show?
- LVH criteria
- T wave inversion in V1 and V2
This is common in <14yr old athletes but past 16 is mostly pathological
Causes of sudden cardiac death
most commonly cardiomyopathy
congenital and anatomical abnormalities
electrical disorders
Vast majority in young athletes <17yrs (sceening could have been easy)
Mobitz type 1
Slightly elongated QTc
What does this ECG of a 16yr old white athlete show? what do these findings suggest?
- short PR interval (this can be normal in athletes)
- TWI extending to V3 (pathological)
- Poor R wave progression (from V1-6 R waves should increase and S decrease)- suggests underlying cardiomyopathic condition
State the criteria for further Ix for anterior TWI
Abnormal if TWI beyond:
- V1 in white
- V4 in black
What other ECG sign can we look at to help us decide whether the TWI is pathological or non-pathological?
ST segment morphology
A = normal athlete shows J point elevation- this is REASSURING
E = ST depression is mostly always pathological
What are the abnormalities in the following ECG an what do these suggest?
- peaked p waves
- TWI in V2/3
- Shallow T wave morphology + Q wave
- prolonged QTc
- prolonged PR
suggests hypokalaemia
Early changes in hypokalaemia
- flattening or T wave inversion
- prominent U waves
- ST segment depression
- prolonged QT interval
Late changes hypokalaemia
- prolonged PR interval
- decreased QRS voltage
- widened QRS
- ventricular arrhythmia
What does the following ECG show?
secondary heart block- Mobitz type 1
Normal in athletes as they are often sinus brady
Why are athletes more likely to exhibit sinus bradycardia?
- increased vagal tone
- reduces intrinsic sinus SAN rate
- reverses on detraining
Are heart blocks common in athletes?
- Junctional rhythm and 1st degree heart block common (PR>200ms)
- Second degree (Mobitz type 1) in 10% athletes
Mobitz type 2 and third degree are rare and warrant further investigation
which ECG findings warrant further investigations?
- TWI
- ST depression
- Pathological Q waves
- Complete LBBB
- Ventricular pre-excitation (delta waves)
- Long QT
- > 2PVCs per 10s
- Tachyrrhythmias
Normal ECG findings in athletes
- sinus brady
- 1st degree AV block
- Mobitz type 1 2nd deg AV block
- Voltage criteria for LVH/RVH
- Incomplete RBBB
- Early repolarisation
- TWI V1-4 in black athletes
Borderline ECG findings in athletes
- Left or right atrial enlargement
- LAD/RAD
- Complete RBBB
if there are 2+, FHx or Sx, further evaluation
Summary of Ix for different ECG findings in athletes
