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Sudden death whilst swimming
the cardiac channelopathies
Dr Anthony J Handley
Medical Adviser, International Lifesaving Federation of Europe
Director, European Resuscitation Council
An 11-year old moderate swimmer in
a supervised lesson in the shallow
end of the pool
He dived under water to pick up an
object but failed to surface
A swimming instructor pulled him
from the pool and lifeguards
commenced CPR within 2-3 minutes
In VF when paramedics arrived –
could not be resuscitated
The findings in the lungs at
autopsy were fully consistent
with drowning
The underlying reason as to
why he ran into difficulties is
not apparent from the post
mortem
The coroner concluded:
After considering the expert
medical evidence, and on the
balance of probability, we were
unable to identify the primary
event that led to Nathan Scott
Matthew’s drowning
Causes of sudden death in the water
Diagnosed at autopsy
Heart attack or stroke
Trauma causing unconsciousness
Sudden cardiac death
Causes of sudden death in the water
No autopsy abnormalities
Seizures, including epilepsy
Diving response or cold shock
Shallow water blackout
Sudden cardiac death
Sudden cardiac death (SCD) is defined as:
‘... death due to cardiac causes ... within one hour
of the onset of acute symptoms ...’
Myerburg & Castellanos A. In Braunwald Heart Disease 1997: 742–79
General population
1 : 1000 pa
Priori et al. Eur Heart J 2001; 22: 1374–1450
Young people (< 35yrs)
0.3-3.6 (1) : 100,000 pa
Borjesson & Pelliccia. Br J Sports Med 2009; 43: 644-648
Non-athletes (< 35yrs)
Athletes (< 35yrs)
0.7 : 100,000 pa
2.1 : 100,000 pa
3 x the risk
Corrado et al. J Am Coll Cardiol 2003; 42: 1959-1963
Estimated 1.5% – 2.5% SCD occur during swimming
1 : 100,000 young people at risk swimming-related SCD
Kenny & Martin. Arch Dis Child 2011; 96: 5-8
SCD during sport
HCM 7%
Ischaemic heart disease 51%
Coronary
abnormalities 4%
ARVC 8%
Myocarditis 4%
Unexplained 11%
Aortic stenosis 3%
Suárez-Mier et al Forensic Sci Int 2013; 226: 188-196
SCD during sport aged < 35 years
HCM 18%
Ischaemic heart disease 14%
Coronary
abnormalities 6%
ARVC 15%
Myocarditis 5%
Unexplained 23%
Aortic stenosis 4%
Suárez-Mier et al Forensic Sci Int 2013; 226: 188-196
Using strict criteria autopsy-negative SCD
in younger subjects - 8%
Tester & Ackerman Pediatr 2012; 33: 461-470
Nearly 30% of under-35-year-olds who suffer
autopsy-negative SUD have a cardiac
channelopathy
Kenny & Martin. Arch Dis Child 2011; 96: 5-8
An ion channel is the route that the ions
(sodium, potassium, calcium) take in and out
of the heart muscle cells to allow the
movement of electricity
Ion channelopathies
Catecholaminergic polymorphic ventricular
tachycardia (CPVT)
Long QT Syndrome (LQTS)
Brugada Syndrome
PCCD (progressive cardiac conduction defect)
Short QT syndrome (SQTS)
Familial atrial fibrillation
Sodium channel disease
Ion channelopathies
Catecholaminergic polymorphic ventricular
tachycardia (CPVT)
Long QT Syndrome (LQTS)
Associated
Brugada
Syndromewith swimming SCD
PCCD (progressive cardiac conduction defect)
Short QT syndrome (SQTS)
Familial atrial fibrillation
Sodium channel disease
Normal
LQTS
Swimming appears to be a gene-specific (KVLQT1)
... trigger for LQTS ... and unexplained drowning ...
may have a genetic basis
Ackerman et al. Mayo Clin Proc 1999; 74: 1088-1094
Pre-participation screening
Young Competitive Athletes
Family & Personal History
Physical Examination
ECG
Negative Findings
Eligible for Competition
Positive Findings
No cardiac
Disease
Further Investigations
Cardiac
Disease
Treatment as necessary
Corrado et al. Eur Heart J 2005; 26: 516-524
False-positive results
Papadakis & Sharma. Br J Sports Med 2009; 43; 663-668
2%
Europe
€ 30
USA
$ 75
‘Cost of preventing each… death would be $ 3.4 million’
Maron et al. Circulation 2007; 115: 1643-1655
Corrado et al. Eur Heart 2005; 26: 516-524
Cost per year per life saved
€ 14,220
X
€ 37,750
Corrado et al. Abstract presented at American Heart Association 2004
NICE: National Institute of Clinical Excellence
NICE's threshold for cost-effective treatment lies
between £20,000 and £30,000 per QALY
1997-2009 Millennium Mathematics Project, University of Cambridge
http://www.plus.maths.org/latestnews/jan-apr10/qaly/
Kidney dialysis
£ 45,000
Coronary artery bypass graft
£ 26,000
Breast cancer screening
£ 6,000
Cervical cancer screening
£
Pre-participation screening
£ 12,350
Hope et al. Medical Ethics and Law 2003. Churchill Livingstone: Chapter 13
200
Screening of athletes / participants
‘The best strategy is to combine … preparticipation identification of athletes affected
… and secondary prevention with back-up
defibrillation … on the athletic field.’
Corrado et al. Eur J Cardiovascular Prev & Rehab 2011; 18: 197-208
Genetic testing
Benefits
Accurate screening test
Can trace others within the family
Can make diagnosis after death
BUT – expensive
Bai et al. Circ Arrhythmia Electrophysiol 2009; 2: 6-15
Genetic testing
$ 45,000 if cases of SUD
$ 71,500 if screening family of SCD
Winlel et al. J Cardiovasc Electrophysiol 2012; 23: 1092-1098
Bai et al. Circ Arrhythmia Electrophysiol 2009; 2: 6-15
Implications for lifeguards
Ensure that lifeguards are aware of the conditions
Consider provision of AEDs at swimming pools
Refer ‘funny turns’ for a medical opinion
Implications for lifeguards
Remember that these conditions are hard or
impossible to diagnose without previous event
or screening
Implications for lifeguards
‘Support’ a lifeguard involved in such an
incident …