Exercise and CVS Flashcards

1
Q

Benefits of exercise

A

CNS - Reduces risk of stroke, dementia, depression
CVS - Reduces risk of CAD, obesity, BP, DM, LDL; 13% decrease in cardiac mortality per MET
Onco - Reduces risk of breast, prostate and bowel CA
MSK - Reduces risk of falls, osteoporosis, disability

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2
Q

MET definition

A

Metabolic unit used to quantify PA intensity; ratio of metabolic rate during exercises to metabolic rate at rest

0 MET = No regular exercise
4 MET = Walking 4mph
10 MET = Brisk jogging

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3
Q

Risks of exercises

A

Increased risk of sudden cardiac death

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4
Q

Triggers of SCD in athletes

A

Acid base and electrolyte imbalance
dehydration
adrenergic surges

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5
Q

Aetiology of SCD

A
  1. Channelopathies
    Long QT syndrome
    Brugada syndrome
    Cathecholaminergic polymorphic VT
  2. Cardiomyopathies
    HOCM
    Arrhythmogenic RV Cardiomyopathy
    Dilated cardiomyopathy
  3. Coronary Artery disease
    Atherosclerosis
    Anomalous coronary ostia

Causes for those with normal heart

  • channelopathies
  • WPW syndrome
  • comotio cordis
  • drugs
  • electrolyte disturbances
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6
Q

What is the peak age (per 100,000)

A

Around 40-50

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7
Q

Mean age

A

23yo (40% of deaths at <18yo)

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8
Q

Epidemiology of SCD

A
1/ 4,000 to 1/50,000 per year
M>F (9:1)
black > white
football and basketball
90% during or immediately after exertion
80% asymptomatic prior
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9
Q

Clinical Presentation

A

FHx

  • known heritable disorder
  • premature death (<50)
  • SCD
  • epilepsy
  • unexplained drowning
  • road traffic accident

Sx
- EXERTIONAL = chest pain, dyspnoea, dizziness, excessive breathlessness, palpitation, epilepsy, prior cardiac disease

O/E
Check weight, peripheral signs around eyes and roof of mouth, pulse and BP, CVS examination

Ix

  • ECG diagnostic in accessory pathways, channelopathies, conduction tissue disorders; 95% HCM abnormal and 80% ARVC
  • ECHO
  • Stress ECG
  • MRI
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10
Q

Hypertrophic Cardiomyopathy

A

Commonest cause of SCD in young athletes
LV outflow tract obstruction from asymmetric septal hypertrophy

Sx

  • Chest pain, dyspnoea, palpitations, presyncope, syncope
  • Aborted SCD
  • Asymptomatic

FHx of HCM or SCD in 1st degree relative

Ix
ECG positive in 95%
- LVH voltage criteria
- T wave inversion inferior lateral
- ST depression
- Q waves 
- LBBB
ECHO

Individualised therapy

  • lifestyle modifications
  • medical therapy
  • surgical therapy
  • family screening

High risk pt –> ICD

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11
Q

Arrhythmogenic RV Cardiomyopathy

A

RV myocardium replaced by fibro-fatty tissue
Progression
1. Myocardial stretch => Asymptomatic
2. Myocyte detachment and myocarditis => VT/ Sudden death, electric storm
3. Fibro-fatty replacement of cardiomyocytes => HF, sudden cardiac death

Sx - palpitation, syncope during exercise

ECG

  • Epsilon waves (positive deflection buried in QRS)
  • T wave inversion
  • Broad QRS in V1-V3
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12
Q

CVD Management of Athletes

A

General: exercise prescription

Specific
WPW => ablation
Marfan => surgery
Anomalous coronary artery => surgery
Comotio cordis => protective clothes/ softballs
Myocarditis => no sports for 3-6months
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13
Q

Cardiovascular adaptations to exercise

A

Electrical

  • sinus bradycardia
  • voltage criteria for LVH
  • repolarisation anomalies

Structural

  • incr LVWT 10-20%
  • incr LV mass 40-65%
  • incr LVED/ RVED 15%
  • incr LA size 20%

Functional

  • incr diastolic filling
  • incr SV

Collectively cause 5x increase in CO
Adaptation - Adult, male, large BSA, endurance, black

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14
Q

Black Athlete’s heart

A

Typically asymptomatic
No FHx

ECG

  • voltage criteria for LVH
  • T wave inversion in V1-4
  • ST segment elevation

TTE

  • Maximal LVWT <=16mm in M and <=13mm in F
  • concentric hypertrophy
  • enlarged LVEDD
  • normal diastolic function
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15
Q

Common combination for false positive diagnosis

A

Mild HCM + Athlete’s heart

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16
Q

Voltage criteria LVH

A

LVH Present when:

  • R in aVL + S in V3 = >28mm in M or >20mm in F
  • R wave in aVL >12mm amplitude
  • S wave in V1 + R wave in V5 or V6 = >35mm

or use Romhilt-Estes LVH Point Score System

17
Q

Investigations for suspected CVD

A

Exercise stress testing - BP response
Cardiopulmonary exercise testing - peak consumption
24hr Holter monitoring - ventricular arrhythmia
Cardiac MRI with gadolinium enhancement - Miyocardial fibrosis

18
Q

Physiological vs Pathological Changes

A

Physiological changes

  • voltage criteria for LVH
  • symmetrical dilatation of ventricles
  • good RV/LV function
  • regression of changes with 4-8wks of detraining

Pathological changes

  • abnormal FHx
  • ventricular tachycardia on holter
  • poor functional capacity/ Low peak VO2
  • Fibrosis = low gadolinium enhancement
  • positive gene test
19
Q

Pre-participation Screening

A

Young competitive athletes

  • > family and personal history, physical examination, ECG
    - >Negative findings => eligible for participation
    - >Positive findings => further Ix
    - ECHO, stress test, 24h Holter, cardiac MRI, angio
    - >Positive findings => Dx and Mx accordingly
    - >Negative findings => eligibility to play

Criteria for further evaluation: Sx, physical examination, ECG

20
Q

Goal of screening

A

To identify silent CV abnormalities that lead to SCD

21
Q

Impact of screening

A

Reduced incidence from 4:100,000 to 0.5:100,000

1 in 300 young athletes affected

22
Q

Concerns regarding ECG screening

A
High cost
Expertise and facilities needed
Low incidence of SCD
Diverse disorders/Effectiveness
- false negatives
- false positives high (23.5% for white and 34% for black [ESC 2010])
23
Q

Role of AEDs in Sports

A

Most sudden cardiac arrests start with VF
Survival affected mostly by time between arrest and defibrillation ; <=50% survival if done within 2-3 mins and <10% if in >10mins
effectiveness of 16-64%

24
Q

Secondary Prevention of SCD

A

Implementing an effective emergency response with high-quality CPR and prompt used of AED

  • Emergency response planning; a regularly rehearsed comprehensive emergency plan to ensure best possible outcome
  • FIFA 11 steps; designed to enhance the resus team’s performance