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
GROUP Incidence of SCD in Specific Populations General population Patients with high coronary-risk profile Patients with previous coronary event Over half of SCA victims have no prior symptoms Patients with ejection fraction < 35%, congestive heart failure Patients with previous out-of-hospital cardiac arrest Patients with previous MI, low EF, and VT 0 5 10 15 20 25 30 0 100,000 200,000 300,000 Incidence of Sudden Death (% of group) No. of Sudden Deaths Per Year Myerburg RJ. Circulation.1998;97:1514-1521.
Severity of Heart Failure Modes of Death NYHA II 12% 24% 64% CHF Other Sudden Death n = 103 NYHA III 26% 59% 15% CHF Other Sudden Death n = 103 NYHA IV CHF 33% 11% 56% Other Sudden Death n = 27 LANCET. 1999;353:2001-07.
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!
AVB An uncommon cause of SCD III V1 Infranodal CHB Torsades with High Grade AVB
Sudden Cardiac Death 400,000/year Non-ischemic Cardiomyopathy Inherited Disorders LQTS, Brugada s, HCM, ARVD 15% Other 5% None 20% Acute MI 80% CAD 80% No Acute MI Underlying Heart Disease Provoking Factor
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)
Out of Hospital Cardiac Arrest Public Place 31 Other 20 Work 4 Time from Cardiac Arrest to First Defibrillation On Street 47 Home 399 Site of Cardiac Arrest The Maastricht Study JACC 1997;30:1500-5. Holmberg et al, AJC 1999
Transvenous ICD components Lead + Device 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
65 yo M with VF / Aborted SCD Acute LAD Total Occlusion Rx d with PTCA EF = 25% post MI, NSVT x 25 beats Recorded 3 weeks after DC home
SCD in Young Athletes 1435 athletes 1980-2005 Note: CAD is still the predominate cause of SCD in older athletes Maron et al, Circ 2007
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 CMR Late gadolinium enhancement HCM with septum 3cm and LGE RV LV
26 yo athlete presented with LB WCT / Syncope ECG after conversion ARVD Episolon Waves / T Wave changes / CMR CMR RV dilation, RVEF = 40%, LVEF = 54% RV
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