A5 - Sudden Cardiac Death

8/7/2019 A5 - Sudden Cardiac Death

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Educational Background:University of Santo Tomas, 1995

Santo Tomas Univ. Hospital, 1996

Post Graduate Training:

Residency Training in Internal Medicine –UP PGHFellowship in Adult Cardiology- UP PGH

Training in Clinical Cardiac Electrophysiology and Pacing

-Philippine Heart Center

Present Positions:Consultant, Philippine Heart Center

ERDIE C. FADREGUILAN, MDFPCP, FPCC

ERDIE C. FADREGUILAN, MDFPCP, FPCC



SUDDEN CARDIAC DEATH

Erdie C. Fadreguilan, MD




• Definition:

“Natural death due to cardiaccauses heralded by abrupt loss of consciousness within one hour of the onset of acute symptoms”



SCA- A Public Health Issue

AIDS2

Breast

Cancer1

LungCancer1

SCD3

SCD claims more

lives each year thanthese other diseasescombined:

The Facts:• Significant Killer in America

• 95% fatal without ICDprotection5 - 98% survivalwith ICD protection

• Nearly 1000 SCA deaths/day6

• ICDs are Class I indicated formost at-risk Pts7

• New guidelines clearly outline

at-risk groups7

• Studies show that ICDs arecost effective8

14,000

41,400

335,000162,500



GROUP

Patients with highcoronary-risk profile

Patients with previouscoronary event

Patients with ejectionfraction <35%,congestive heart failure

Patients with previousout-of-hospital cardiacarrest

Patients with previousmyocardial infarction,low ejection fraction,and ventriculartachycardia

General population

Incidence of SCD in Specific Populationsand Annual SCD Numbers

Myerburg RJ. Circulation.1998;97:1514-1521.

300,000200,000100,0000

No. of SuddenDeathsPer Year

3025201050

Incidence of SuddenDeath(% of group)



What Is SCA?

• Electrical system in heart malfunctions

• Heart unexpectedly, abruptly stops beating

• Often caused by an abnormal heart rhythmcalled ventricular fibrillation (VF)

– VF accounts for half of all cardiac deaths

• Rapid, chaotic heartbeat

• Lower heart chambers, or ventricles,spasm

• Heart functioning stops

• Lack of oxygen in body, brain is dead



Etiology of Sudden Cardiac Death

• An estimated 13 million people had coronary heart disease (CHD) in the U.S. in 2002. 1

• Sudden death was the first manifestation of CHD in 50% of men and 63% of women.1

• CHD accounts for at least 80% of sudden cardiac deaths in Western cultures.3

1 American Heart Association. Heart Disease and Stroke Statistics2003 Update. Dallas, Tex.: American HeartAssociation; 2002.

2 Adapted from Heikki et al. N Engl J Med , Vol. 345, No. 20, 2001.

3 Myerberg RJ. Heart Disease, A Textbook of Cardiovascular Medicine. 6th ed. P. 895.

Etiology of Sudden Cardiac Death2,3

* ion-channel abnormalities, valvular or congenital heart disease, othercauses

80%Coronary

HeartDisease

15%Cardiomyopathy

5% Other*




• Epidemiology– SCD due to Coronary Artery

disease: single most importantcause of death in adult population

–Ventricular Fibrillation: 75-80%–Bradyarrhythmias: minority

– SCD in the absence of CAD, CHF:

5-10% of cases



Arrhythmic Cause of SCD

Albert CM. Circulation. 2003;107:2096-2101.

12%Other CardiacCause

88%

ArrhythmicCause



PrimaryPrimary

VFVF

8%8%

Underlying Arrhythmia of Sudden CardiacArrest

Adapted from Bayés de Luna A. Am Heart J. 1989;117:151-159.

TorsadesTorsades

de Pointesde Pointes

13%13%

Bradycardia17%

VTVT

62%62%



Sustained Monomorphic VT

72-year-old woman with CHD



VF with Defibrillation (12-lead ECG)



Torsades de Pointes



SCA Survival & MortalityData

• At least 335,000 SCA deaths in the U.S.each year

• Only 5 to 10% survive first episode of SCA

• Roughly two-thirds of SCA deaths occurout-of-hospital– 5% estimated survival rate

Seidl K, Senges J. Card Electrophysiol Rev. 2003;7:5-13.

Heart Disease and Stroke Statistics 2005 Update. AHA. www.americanheart.org

Crespo EM, Kim J, Selzman KA. Am J Med Sci. 2005;329:238-246.

Zheng ZJ, et al. Circulation. 2001;104:2158-2163.

Zipes, DP, et al. 2006 ACC/AHA/ESC Practice Guidelines 5. Circulation. 2006;114;385-484.



Cummins RO. Annals Emerg Med. 1989;18:1269-1275.

SCA Resuscitation Success vs.Time*

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9

%

Success

*Non-linear

Time (minutes)

Chance of success reduced7 - 10% each minute



Can SCA be Prevented?

• Research and clinical studies haveidentified several conditions that putpatients at a high risk for SCA

• Patients can be evaluated for these known

risk factors before they experience a SCA

• Treatment options are available that canprevent sudden cardiac death



Risk Factors for Sudden CardiacArrest

• Previous Sudden Cardiac Arrest (SCA) Event• Prior Episode of Ventricular Tachyarrhythmia

(VT)

• Previous Myocardial Infarction (MI)

• Coronary Artery Disease (CAD)• Heart Failure

• Genetic diseases

– Long QT Syndrome

–Hypertrophic Cardiomyopathy (HCM)– Brugada Syndrome

– ARVD

– SUDS



Myerburg RJ. Heart Disease, A Textbook of Cardiovascular Medicine, 5th ed, Vol 1.Philadelphia: WB Saunders Co;1997:ch 24.Fogoros RN. Practical Cardiac Diagnosis: Electrophysiologic Testing, 2nd ed. Blackwell Science, pp 172.The AVID Investigators. N Engl J Med. 1997;337:1576-1583.Myerburg RJ. Ann Intern Med.. 1993;119:1187-1197.Demirovic J. Progr Cardiovasc Dis. 1994;37:39-48.Friedlander Y. Circulation. 1998;97:155-160.

Sudden Cardiac Arrest Survivors

• Highest risk factor for Sudden Cardiac Arrest is

a previous SCA event

• 30 to 50% of SCA survivors will experienceanother SCA event within one year

• First-degree relatives of SCA patients have a50% higher risk of MI or primary cardiac arrest



Myerburg RJ. Heart Disease, A Textbook of Cardiovascular Medicine, 5th ed, Vol 1.Philadelphia: WB Saunders Co;1997:ch 24.Fogoros RN. Practical Cardiac Diagnosis: Electrophysiologic Testing, 2nd ed. Blackwell Science, pp172.The AVID Investigators. N Engl J Med. 1997;337:1576-1583.

Prior Episode of VT

• VT with syncope or a low ejection

fraction (LVEF < 40%) leads to anincreased risk of Sudden Cardiac Arrest

• The one-year risk of Sudden CardiacArrest for these patients ranges from 20to 50%



SCA Relationship to MI

• A previous MI can be identified in asmany as 75% of SCA patients.

• A previous MI as a single risk-factorraises the one-year risk of SCA by 5%.

• The five-year risk of SCA is 32% forpatients with all of these risk-factors:• history of MI

• non-sustained, inducible, non-suppressibleVT

• LVEF ≤ 40%

Sudden Cardiac Arrest Fast Facts. HRS. www.hrsonline.org

Risk factors for sudden cardiac death. www.heartinstitute.org.au/Community/scdMain.asp

Buxton AE, et al. N Engl J Med. 1999;341:1882-1890.

Ti D d f M t lit Ri k P t MI



Time Dependence of Mortality Risk Post-MIPrediction of Sudden Cardiac Death After Myocardial Infarction

in the Beta-Blocking Era1

• 700 post-MI patients;~ 95% on beta-blockers2 years after discharge.

• The epidemiologicpattern of SCD wasdifferent from thatreported in previousstudies.

–Arrhythmia events didnot concentrate earlyafter the index event;

most occurred > 18months post-MI.

1 Huikuri HV. J Am Coll Cardiol. 2003;42:652-658.

Total

Mortality

CardiacMortality

Non-SCD

SCDCumulativ e

Events(%)

18

15

12

9

6

3

18

15

12

9

6

3

20

40

60 20

40

60

Follow-Up (months) Follow-Up (months)

l i f i f C fi



14

11.6

8.47.89

8.2

4.9

7.2

0

2

4

6

8

10

12

14

16

1-17 mo 18 - 59 mo 60 - 119 mo > 120 mo

Conv

ICD

(n =300)

(n =283)

(n =284)

(n =292)Hazard

Ratio.98

(p = 0.92)

0.52

(p = 0.07)

0.50

(p = 0.02)

0.62

(p = 0.09)

Wilber, D. Circulation. 2004;109:1082-1084.

Relation of Time from MI to ICD Benefitin the MADIT-II Trial

Time from MI%

Mortalityf or

Each

T

imeP

eriod



SCD Rates in Post-MI Patientswith LV Dysfunction

2119.8

14

10

7

16 16

12 9.4

28

1820

28

0

10

20

30

TRACE CAPRICORN EMIAT MADIT MUSTT

Inducible

MUSTT

Registry

MADIT II*

Control Group Mortality at 2 year

Total Mortality

Arrhythmic Mortality

Total Mortality ~20-30%; SCDaccounts for ~50% of the total deaths.



“People who’ve had a heart attackhave a sudden death rate that is 4-6

times that of the general population.”1

“ People who have had a heart attackand have LV dysfunction (</=40%) havea sudden death rate that’s similar to a

CHF population.”1American Heart Association. Heart Disease and Stroke Statistics2003Update. Dallas, Tex.: American Heart Association; 2002.



SCD in Heart Failure 1, 2

• Despite improvements inmedical therapy, symptomatic

HF still confers a 20-25% riskof premature death in the first2.5 yrs after diagnosis.– ≈ 50% of these premature

deaths are SCD (VT/VF)1 Bardy G. The Sudden Cardiac Deatth-Heart Failure Trial

(SCD-HeFT) in Woosley RL, Singh S, ArrhythmiaTreatment and Therapy, Copyright 2000 by MarcelDekker, Inc. , pp. 323-342,

2 Sweeney MO PACE 2001;24:871-888.



SCA Relationship to HF

• Patients with HF are overall at 6-9 times higherrisk for SCD than general population

• As HF progresses, pump failure (rather than SCA)

becomes relatively more likely as the cause of death

• Reduced LVEF remains the single most important

risk factor for overall mortality and suddencardiac death.

Heart Disease and Stroke Statistics – 2005 Update. AHA. www. americanheart.org

S it f H t F il



Severity of Heart FailureModes of Death

12%

24%64%

CHF

Other

SuddenDeath(N = 103)

NYHA II

26%

15%59%

CHF

Other

SuddenDeath

(N = 103)

NYHA III

56%11%

33%

CHF

Other

SuddenDeath(N = 27)

NYHA IV SCA Pump Failure

NYHA Class II 64% 12%

NYHA Class III 59% 26%

NYHA Class IV 33% 56%



LVEF and SCA Incidence

Vreede-Swagemakers JJ. J Am Coll Cardiol. 1997;30:1500-1505.

LVEF

0

1

2

3

4

5

6

7

8

0-30% 31-40% 41-5 0% > 50%%

SCAV

ictims

7.5%

5.1%

2.8%

1.4%



SCD

•Genetic Basis

– Short QT syndrome

– Long QT Syndrome

– Brugada Syndrome

– Hypertrophic Cardiomyopathy

– Arrhythmogenic Right Ventricular Cardiomyopathy– Catecholaminergic Polymorphic Ventricular

Tachycardia

• Family history is a strong independent predictor of susceptibility to SCD



Schwartz PJ. Curr Probl Cardiol. 1997;22:297-351.Smith WM. Ann Intern Med. 1980;93:578-584.Garson A Jr. Circulation. 1993;87:1866-1872.

Long QT Syndrome

• Congenital disorder that may lead tounexplained syncope, seizures, and SCA

• Either asymptomatic or are prone tosymptomatic and potentially lethal arrhythmias

• 60% have a positive family history of LQTS orSCA

• Necessary to identify other family members atrisk



Long QT Syndrome in a 16-year-old girl



Myerburg RJ. Heart Disease, A Textbook of Cardiovascular Medicine. 5th ed, Vol 1.Philadelphia: WB Saunders Co; 1997:ch 24.Maron BJ. New Engl J Med. 2000;342:365-373.

Hypertrophic Cardiomyopathy

• SCD is the most common cause of death

• Prevalence is about 0.2% of the general populationand about 10% of HCM patients are considered tobe at high risk of SCA

• Over a ten year period > 50% of high-risk patients

would experience SCA

• Most common cause of SCA in athletes under age35



Arrhythmogenic RVDysplasia

• RV myocardium isprogressively replacedby fibrofatty tissue. LV isnormal

• LBBB morphology

• High risk of SCD if arrhythmias are leftuncontrolled

• Risk stratification isimportant

• Tx: Drugs, ICD, ablation

• Prevent arrhythmicdeath influenced byautonomic tone

Zipes and Jalife, 2001



Arrhythmogenic RV Cardiomyopathy



Brugada Syndrome

• ECG pattern of ST segmentelevation in V1 to V3 withRBBB morphology and

syncopal or sudden deathepisodes in patients withstructurally normal hearts

• Male predominance



Brugada Syndrome



Brugada Syndrome• Incidence

–Ubiquitous

–Cause of 4-12% of all sudden deaths

• Prevalence ?

• Pharmacologic maneuvers with Nablockers (Ajmaline, Flecainide,Procainamide) may unmask abnormalECG



Brugada Syndrome

• Etiology and Genetics

• SCN5A mutation

–Encodes Na channel

• Autosomal dominant pattern

• Males more prone to

phenotype (typical ECG andventricular arrhythmias)



Brugada Syndrome

• Na channel blockers worsenECG findings

• Isoproterenol controls

electrical storm• Prognosis and Treatment:

–Poor if left untreated

– ICD: Treatment of choice



SUDS

• 1997 Dr. KoonlaweeNademanee

• Thailand: “Lai Tai”• Japan: “Pokkuri”

• Philippines: “Bangungut”

• “Dying in their sleep”



SUDS

• Clinical Presentation:–Agonal respiration

–Unresponsiveness afterlabored respiration duringsleep or seizure-like

symptoms–Normal cardiac function



SUDS & Brugada

• No organic heart disease

• Males exclusively

•High incidence of induciblepolymorphic VT to VF

• High mortality rate

• Normalization of ECG on exercise• EP mechanism same ??



Treatment Options for SCA

• Defibrillation is theonly effectivetreatment for SCA

• VF tends to rapidlydeteriorate intoasystole

• Asystole cannot besuccessfully treated

with defibrillation



• Small devices, pectoralimplant site

• Transvenous, single incision

• Local anesthesia; conscious sedation

• Short hospital stays

• Few complications

• Perioperative mortality < 1%

• Programmable therapy options

• Single- or dual-chamber therapy

• Battery longevity up to 9 years

• 80,000 implants/year (2000 E)1

Implantable Cardioverter Defibrillator

First-line therapy for patients at risk for SCA

1Morgan Stanley Dean Witter. Investors Guide to ICDs. 2000.

Key Randomized Clinical



Key Randomized ClinicalTrials

Adapted from: DiMarco JP. N Engl J Med . 2003;349:1836-47. www.medscape.com

Young JB. Sudden cardiac death in heart failure. www.medscape.com

ICD therapy for the secondary prevention of SCA

Mortality

(%)

Trial N Age (yrs) Mean LVEF(%)

Follow-up(mos)

ControlTherapy

Control ICD P

AVID 1016 65 ± 10 35 18 ± 12 Amiodarone or sotalol

24.0 15.8 .02

CIDS 659 64 ± 9 34 36 Amiodarone 29.6 25.3 .14

CASH 288 58 ± 11 45 57 ± 34 Amiodarone or metoprolol

44.4 36.4 .08



2006 ACC/AHA/ESC Guidelines for theManagement of Ventricular Arrhythmias:

Secondary Prevention of SCD

ICD Class I Recommendation:• Patients with a history of SCA, VF,

hemodynamically unstable VT, or unexplainedsyncope

Zipes, DP, et al. 2006 ACC/AHA/ESC Practice Guidelines 5. Circulation. 2006;114;385-484



Myerburg RJ, et al. Circulation. 1998. 97:1514-1521.

Patients with a previous cardiac arrest are at high risk for subsequent SCA

events but account for a small percentage of annual sudden deaths

MADIT I, MUSTT

AVID, CASH,

CIDS

SCD-HeFT,MADIT II



Key Randomized Clinical Trials

Adapted from: DiMarco JP. N Engl J Med. 2003;349:1836-47. www.medscape.com

Kadish A, et.al. N Engl J Med 2004;350:2151-8.

Young JB. Sudden cardiac death in heart failure. www.medscape.com

ICD therapy for the primary prevention of SCAMortality (%)

Trial N Age(yrs)

MeanLVEF (%)

Follow-up(mos)

ControlTherapy

Control ICD P

SCD-HeFT 2521 60.1 25 45.5 Optimal

MedicalTherapy

36.1 28.9 .007

MADIT 196 63 ± 9 26 27 Conventional 38.6 15.7 .009

MADIT II 1232 64 ± 10 23 20 OptimalMedicalTherapy

19.8 14.2 .007

MUSTT 704 67 ± 12 30 39 No EP-guidedtherapy 48 24 .06

DEFINITE 458 58 21 29.0±14.4 OptimalMedicalTherapy

14.1 7.9 .08

Heart Failure and Left Ventricular Dysfunction are

http://www.medscape.com/

http://www.medscape.com/



Myerburg RJ, et al. Circulation. 1998. 97:1514-1521.

Heart Failure and Left Ventricular Dysfunction are

indicators of SCA risk

MADIT I, MUSTT

AVID, CASH,CIDS

SCD-HeFT,MADIT II

2006 ACC/AHA/ESC Guidelines for the



2006 ACC/AHA/ESC Guidelines for theManagement of Ventricular Arrhythmias: Primary

Prevention of SCD

ICD Class I Recommendations:• Patients with ischemic cardiomyopathy who are at least 40

days post-MI with an LVEF ≤ 30 - 40% and NYHA functionalclass II or III

• Patients with NYHA Class II-III, LVEF ≤ 30 - 35%, non-ischemiccardiomyopathy

• Patients who are at high risk of SCA due to genetic disorderssuch as long QT syndrome, Brugada syndrome, hypertrophiccardiomyopathy and arrhythmogenic right ventricular dysplasia(ARVD).


2006 ACC/AHA/ESC Guidelines for the



2006 ACC/AHA/ESC Guidelines for theManagement of Ventricular Arrhythmias: Primary

Prevention of SCD

ICD Class II Recommendation:• Ischemic and non-ischemic patients with NYHA functional

class I, LVEF ≤ 30-35%


Many methods to further risk stratify patients



Many methods to further risk stratify patientsrisk for SCA have been studied...

Test Objective Sensitivity

(%)

Specificity

(%)

Limitations

Echo Measurement of LVEF

55–65 75–80

HR

variability

Assessment of lowheart rate variability

38–62 75–88 Multiple non-standardized methods

EP Study Induction of VA’s 48–73 65–93 Invasive, expensive

Signal

AveragedECG

(SAECG)

Induction of latepotentials

56-68 74–81 Not useful in non-ischemic cardiomyopathy

Microvolt

T-WaveAlternans(MTWA)

Identification of

repolarizationabnormalities

77–93 37–83 Cannot be used in AF

Siddiqui A, Kowey PR. Curr Opin Cardiol. 2006;21:517-25.

Prior SG, et al. Eur Heart J, Vol 22:16:August 2001

But a reduced EFremains the singlemost important riskfactor for overallmortality and suddencardiac death.

E l ti P ti t t Ri k f SCA



Evaluating Patients at Risk for SCA

• Electrophysiology Studies (EPS) have been helpful

in the diagnosis of cardiac arrhythmias including:– Sinus and AV node dysfunction

– Conduction abnormalities

– Accessory pathways of conduction

– Inducibility of VT

• EPs can provide advanced treatments includingImplantable Cardioverter Defibrillators (ICDs) and

ablation therapy



Conclusions

• The key to SCD prevention is to identifyhigh risk patients BEFORE they have aSCA event. The majority of cases are in

patients with:

– Coronary artery disease, previous MI

– Low left ventricular ejection fraction

– Dilated cardiomyopathy and heart failure



INTERACTIVE SESSION

Which is NOT a recognized risk factor



Which is NOT a recognized risk factorfor SCD?

a. Short QT interval

b. Brugada Syndrome

c. Hypertrophic Cardiomyopathy

d. Family History of SCD

li i l t ti f SUDS



clinical presentation of SUDSexcept:

a. agonal respiration

b. unresponsiveness afterlabored respiration duringsleep or seizure-like

symptomsc. Depressed cardiac function



Thank You

A5 - Sudden Cardiac Death

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