Sudden cardiac arrest/Death by Dr. Shahab Abdi

2. Sudden Cardiac
Arrest/Death
Professor: Dr. Seyed Mohammadzadeh
Presentation: Dr. Shahab Abdi
Reference: UptoDate

3. INTRODUCTION
 sudden cessation of cardiac activity with hemodynamic collapse, typically due to
sustained ventricular tachycardia/ventricular fibrillation.
 The event is referred to as SCA (or aborted SCD) if an intervention (eg,
defibrillation) or spontaneous reversion restores circulation, and the event is called
SCD if the patient dies

4. DEFINITIONS
American College of Cardiology/American Heart Association/Heart Rhythm
Society (ACC/AHA/HRS) :
 "[Sudden] cardiac arrest is the sudden cessation of cardiac activity so that the
victim becomes unresponsive, with no normal breathing and no signs of
circulation.
 If corrective measures are not taken rapidly, this condition progresses to sudden
death.
 Cardiac arrest should be used to signify an event as described above, that is
reversed, usually by CPR and/or defibrillation or cardioversion, or cardiac pacing.
 Sudden cardiac death should not be used to describe events that are not fatal."

5. PREMONITORY SYMPTOMS
 There are usually no premonitory symptoms
 If symptoms are present, they are nonspecific and include:
 chest discomfort
 Palpitations
 shortness of breath
 weakness

6. EPIDEMIOLOGY
 SCD accounts for approximately 15 percent of the total mortality in the United
States
 The estimated number of sudden cardiac deaths in the United States in 1999 was
approximately 450,000
 The incidence increases dramatically with age and with underlying cardiac disease
 men are two to three times more likely to experience SCA

7. EPIDEMIOLOGY
The magnitude of the influence of underlying cardiac disease on the risk of SCA
 ↑risk 6-10x in the presence of clinically recognized heart disease
 2-4x in the presence of coronary heart disease (CHD) risk factors
 SCD is the mechanism of death in over 60% of patients with known CHD
 SCA is the initial clinical manifestation of CHD in approximately15%

8. ETIOLOGY
 Ischemic heart disease
 As much as 70 percent of SCAs, can occur both during ACS and CHD
 Nonischemic heart disease
 ~10 percent of cases of out-of-hospital SCA
 Nonstructural heart disease
 Noncardiac disease

9. ETIOLOGY
Ischemic heart disease
 Coronary artery disease with myocardial infarction or angina
 Coronary artery embolism
 Nonatherogenic coronary artery disease (arteritis, dissection, congenital coronary
artery anomalies)
 Coronary artery spasm

10. ETIOLOGY
Nonischemic heart disease
 Hypertrophic cardiomyopathy
 Dilated cardiomyopathy
 Valvular heart disease
 Congenital heart disease
 Arrhythmogenic right ventricular dysplasia
 Myocarditis
 Acute pericardial tamponade
 Acute myocardial rupture
 Aortic dissection

11. ETIOLOGY
Nonstructural heart disease
 Primary electrical disease (idiopathic ventricular fibrillation)
 Brugada syndrome (RBBB and ST segment elevation in leads V1 to V3)
 Long QT syndrome
 Pre-excitation syndrome
 Complete heart block
 Familial sudden cardiac death
 Chest wall trauma (commotio cordis)

12. ETIOLOGY
Noncardiac disease
 Pulmonary embolism
 Intracranial hemorrhage
 Drowning
 Pickwickian syndrome
 Drug-induced
 Central airway obstruction
 Sudden infant death syndrome

13. RISK FACTORS
 Dyslipidemia
 Hypertension
 Cigarette smoking
 Physical inactivity
 Obesity
 Diabetes mellitus
 Excess alcohol intake
 Family history of premature CHD or myocardial infarction

14. Primary prevention in general population
There are two approaches to reduce the risk of SCA in the general population
 Screening and risk stratification to identify individuals who may benefit from
specific interventions(eg, stress testing, screening ECGs).
 Interventions that may be expected to reduce SCA risk in any individual

15. Screening and risk stratification
 Among populations already known to be at an elevated risk of SCA (eg, patients
with a prior myocardial infarction), further risk stratification with a variety of tests
can identify subgroups that benefit from specific therapies, such as an ICD.
 However, in the general population without known cardiovascular disease, there is
no evidence that routine screening with any test effectively identifies populations
at an increased risk of SCA.

16. Risk factor reduction
 Effective treatment of hypercholesterolemia
 Effective treatment of hypertension
 Adoption of a heart-healthy diet
 Regular exercise
 Smoking cessation
 Moderation of alcohol consumption
 Effective treatment of diabetes

17. Primary prevention in other groups
 Post MI:
 Standard medical therapies(Both beta blockers and ACE inhibitors)
 Risk stratification to identify those patients at the highest risk of SCA
 ICD implantation in selected patients
 Heart failure and cardiomyopathy:
 Primary prevention with an ICD is recommended in selected patients with either
ischemic or nonischemic cardiomyopathy
 standard medical therapies for HF (beta blockers, ACE inhibitors and aldosterone
inhibitors)

18. SECONDARY PREVENTION
 ICD therapy is the preferred therapeutic modality in most survivors of SCA.
 The ICD does not prevent the recurrence of malignant ventricular arrhythmias, but
it effectively terminates these arrhythmias when they do recur.
 Antiarrhythmic drugs are less effective than an ICD for secondary prevention of
SCD.
 Thus, their use in this setting is limited to the adjunctive role in ICD patients who
have frequent arrhythmia recurrences and device discharges

19. Managementofpulselessarrest

20. Thank you for your attention