Sudden Cardiac Death What an electrophysiologist thinks a
cardiologist should know
Steven J. Kalbfleisch, M.D.
Medical Director Electrophysiology Laboratory
Ross Heart Hospital
Wexner Medical Center
Sudden Cardiac Death (SCD) Death within 1hr of sx onset
300,00-400,000 Victims Annually (0.1% of population)
SCD accounts for 50% of all cardiac related deaths and
15% of total mortality in US.
Primary Cause is Arrhythmic
Older data - VT/VF (75%), Asystole/PEA (25%)
Newer data - Asystole/PEA (50%)
Recurrence Rate is up to 30% annually among Survivors
Incidence of SCD in Specific Populations
Myerburg RJ. Circulation.1998;97:1514-1521.
GROUP
300,000
Patients with high coronary-risk profile
Patients with previous coronary event
Patients with ejection fraction < 35%, congestive heart failure
Patients with previous out-of-hospital cardiac arrest
Patients with previous MI, low EF, and VT
General population
200,000 100,000 0
No. of Sudden Deaths Per Year
30 25 20 15 10 0
Incidence of Sudden Death (% of group)
5
Over half of
SCA victims
have no prior
symptoms
Severity of Heart Failure Modes of Death
LANCET. 1999;353:2001-07.
12%
24%
64%
CHF
Other
Sudden Death n = 103
NYHA II
26%
15%
59%
CHF
Other
Sudden Death
n = 103
NYHA III
56%
11%
33%
CHF
Other
Sudden Death n = 27
NYHA IV
Sudden Death Is Frequently Due To Ventricular
Tachycardia Degenerating To Ventricular Fibrillation
The rhythm recorded depends on the timing of the recording
24 hr Holter on during CHF Event /
Respiratory Arrest
Just because asystole occurred doesn’t
mean that is what they died from!
III
V1
AVB – An uncommon cause of SCD
Torsades with High Grade AVB
Infranodal CHB
Sudden Cardiac Death
400,000/year
Provoking Factor Underlying Heart Disease
80% No Acute MI
20% Acute
MI
80% CAD
15%
Other
5%
None
• Non-ischemic Cardiomyopathy
• Inherited Disorders
– LQTS, Brugada’s, HCM, ARVD
Ventricular Arrhythmias as a Cause of
Syncope / SCD
• Monomorphic Ventricular Tachycardia • Scar related
• Polymorphic VT / Ventricular fibrillation • Acute MI / ischemia / NICM
• Torsades de Pointes • Congenital long QT
• Drug / Metabolic induced
65 yo M with CAD, s/p CABG with syncope and WCT
Sustained monomorphic VT = Scar related
65 yo M with CP in ER – PVMT / VF = think ischemia
68 y/o woman, Hx PAF / CAD, LVEF 50%
Rx’d with Sotolol 120mg Bid
Iatrogenic SCD!
No mortality benefit with any antiarrhythmic
in any patient group
Proven Treatment for SCD
• Bystander CPR
• External defibrillators (AEDs)
• Medications - BBs and ACEI in high
risk groups (Post MI, CHF)
• ICD therapy (including CRT in select
patients)
JACC 1997;30:1500-5.
Out of Hospital Cardiac Arrest
Home
399
On Street
47
Public Place
31
Other
20
Work
4
Site of Cardiac Arrest
The Maastricht Study Holmberg et al,
AJC 1999
Time from Cardiac Arrest to
First Defibrillation
ICD components
Lead + Device Transvenous SICD
ICD shock
ICD Indications – Black / White
• OK to Implant – Secondary Prevention (aborted SCD, Sustained VT,
syncope in high risk group)
– EF < 30% / CAD / Prior MI
– EF < 35% / CHF (class II / III),
– CHF (class IV) if implanting with CRT
• Not OK to Implant (for Primary Prevention) – MI < 40 days
– Revascularization < 3 months
– CHF < 3 months
– Class IV CHF or Class I Non-ischemic
– Life expectancy < 1 yr
Recorded 3 weeks after DC home
65 yo M with VF / Aborted SCD
Acute LAD Total Occlusion Rx’d with PTCA
EF = 25% post MI, NSVT x 25 beats
SCD in Young Athletes 1435 athletes 1980 - 2005
Maron et al, Circ 2007
Note: CAD is still the predominate cause of SCD in older athletes
What can you catch with an ECG?
• HCM – The largest group in the USA
• ARVD – the Largest group in Italy
• The “Channelopathies”
– Long QT
– Brugada Syndrome
25 yo M had SCD event during
basketball game
Late gadolinium
enhancement
LV
RV
CMR
HCM with septum 3cm
and LGE
26 yo athlete presented with LB WCT / Syncope ECG after conversion
ARVD – Episolon Waves / T Wave changes / CMR
RV CMR
RV dilation, RVEF = 40%, LVEF = 54%
40 yo M presented after a syncopal episode ST-segment Elevation - V1 Through V3 – Type I Brugada
Family Hx of SCD – Uncle died in sleep
The Evolution of SCD therapy Drug vs Device
Major ICD Trials
Recent CABG
< 40 days from MI
*
*
*
= secondary prevention *