B P7 C70 Cardiac Arrest and Sudden Cardiac Death

Question 1

SCD is natural death from cardiac causes heralded by abrupt loss of consciousness within _____ hour of the onset of an acute change in cardiovascular status.

Answer 1

1 hour

As such detailed information is often lacking, various definitions of SCD include up to a 24 hour period and death during sleep.

Question 2

To satisfy clinical, scientific, legal, and social considerations, four temporal elements must be considered:

Answer 2

(1) Prodromes
(2) Onset
(3) Cardiac arrest
(4) Biologic death

Question 3

The 1-hour definition primarily refers to the duration of the “_____,” which defines the interval between the onset of symptoms signaling the pathophysiologic disturbance leading to cardiac arrest and the onset of the cardiac arrest itself

Answer 3

Terminal event

Question 4

_____, occurring weeks or months before an event, are generally predictors of an impending cardiac event, but not specific for SCA itself.

The same premonitory signs and symptoms may be more specific for imminent cardiac arrest when they begin abruptly.

Answer 4

Prodromes

Question 5

Sudden onset of chest pain, dyspnea, or palpitations and other symptoms of arrhythmias often precede the onset of _____ and define the onset of the 1-hour terminal event period that brackets the cardiac arrest.

Answer 5

Cardiac arrest

Question 6

The fourth element, _____, is an immediate consequence of cardiac arrest, unless there is a successful intervention, and usually occurs within minutes

Answer 6

Biologic death

Question 7

Examples of substrate-based risk

Answer 7

Coronary heart disease
State of epicardial and intramyocardial vessels Myocardial infarction
Myopathy, infiltration, inflammation, valvulopathy Hypertrophy; myocardial fibrosis

Question 8

Examples of expression-based risk

Answer 8

Left ventricular dysfunction and heart failure Metabolic abnormalities
Autonomic dysfunction

Question 9

Examples of mechanism-based risk

Answer 9

VF/pulseless VT
PEA
Asystole

Question 10

Three factors are of primary importance for identification of populations at risk and consideration of strategies for prevention of SCD:

Answer 10

(1) the Absolute numbers and event rates (incidence) among population subgroups
(2) the Clinical subgroups in which SCDs occur
(3) Competing risks
(4) the time dependence of risk

Question 10

Genetic Contributors to Risk for Sudden Cardiac Death

Genetically Based Primary Arrhythmia Disorders

Answer 10

Congenital long-QT syndrome, short-QT syndrome Brugada syndrome
Catecholaminergic polymorphic VT/VF
J wave syndromes
Nonsyndromic VT/VF

Question 11

Genetic Contributors to Risk for Sudden Cardiac Death

Inherited Structural Disorders with Risk for Arrhythmic SCD

Answer 11

Hypertrophic cardiomyopathy
Right ventricular dysplasia/cardiomyopathy

Question 12

Genetic Contributors to Risk for Sudden Cardiac Death

Genetic Predisposition to Induced Arrhythmias and SCD

Answer 12

Drug-induced “acquired” long-QT syndrome (drugs, electrolytes)

Electrolyte and metabolic arrhythmogenic effects

Question 12

Genetic Contributors to Risk for Sudden Cardiac Death

Genetic Modulation of Complex Acquired Diseases

Answer 12

Coronary artery disease, acute coronary syndromes Congestive heart failure, dilated cardiomyopathies

Question 13

Although the pathologic anatomy associated with SCD caused by coronary artery disease often reflects the changes associated with acute myocardial injury,<_____% of survivors of OHCA have clinical evidence of a new transmural MI

Answer 13

<20%