SUDDEN CARDIAC DEATH
Albotothia Ali Hussein Ali
Tula State University, Tula
Scientific supervisor – Ovchinnikov Victor Vyacheslavovich
Sudden cardiac death is an unexpected death due to cardiac causes that occurs in a short
time period (generally within 1 hour of symptom onset) in a person with known or unknown
cardiac disease. It is estimated that more than 7 million lives per year are lost to SCD
worldwide, including over 300,000 in the United States. It has so many signs and symptoms,
risck factors, ways for diagnosing, and ways for management.
Keywords: SCD; sudden cardiac death.
A natural disaster hits, the power goes off and the lights go out. It's a common scene
that plays out during hurricane and tornado seasons, and it's very similar in trying to explain
sudden cardiac arrest. The heart sustains an insult, the electricity is short circuited, the heart
can't pump, and the body dies. It breaks down the mechanism of blood bumping that is
happening in normal cases. The heart muscle can't supply blood to the body, particularly the
brain, and the body dies. Ventricular fibrillation is the most common reason for sudden death
in patients. Ventricular Fibrillation is treated with electrical shock, but for it to be effective,
the shock usually needs to happen within less than four to six minutes, not only for it to be
effective, but also to minimize brain damage from lack of blood and supply of oxygen.
SCD has many signs and symptoms such as chest pain, fatigue, palpitations, and other
nonspecific complaints. Factors relating to the development of coronary artery disease (CAD)
and, subsequently, myocardial infarction (MI) and ischemic cardiomyopathy include the
following:
 Family history of premature coronary artery disease
 Smoking
 Dyslipidemia
 Hypertension
 Diabetes
 Obesity
 Sedentary lifestyle [11].
SCD has many specific factors relating to cardiovascular disease such as:
1) Coronary heart disease
a) Previous cardiac arrest
b) Syncope
c) Prior myocardial infarction, especially within 6 months
d) Ejection fraction of less than 30-35%
e) History of frequent ventricular ectopy: More than 10 premature ventricular
contractions (PVCs) per hour or nonsustained ventricular tachycardia (VT)
2) Dilated cardiomyopathy
a) Previous cardiac arrest
b) Syncope
c) Ejection fraction of less than 30-35%
d) Use of inotropic medications
3) Hypertrophic cardiomyopathy
a) Previous cardiac arrest
b) Syncope
c) Family history of SCD
d) Symptoms of heart failure
e) Drop in systolic blood pressure (SBP) or ventricular ectopy upon stress testing
f) Palpitations
g) Most persons are asymptomatic
4) Valvular disease
a) Valve replacement within past 6 months
b) Syncope
c) History of frequent ventricular ectopy
d) Symptoms associated with severe, uncorrected aortic stenosis or mitral stenosis
5) Long QT syndrome
a) Family history of long QT and SCD
b) Medications that prolong the QT interval
c) Bilateral deafness [3,7,12].
There are many risk factors that can increase a person's risk of sudden cardiac arrest and
sudden cardiac death, including the following:
 Previous heart attack with a large area of the heart damaged (75% of SCD cases are
linked to a previous heart attack).
 A person's risk of SCD is higher during the first 6 months after a heart attack.
 Coronary artery disease (80% of SCD cases are linked with this disease).
 Risk factors for coronary artery disease include smoking, hypertension, family history of
heart disease, and high cholesterol.
 sudden cardiac death increases with age in both men and women.( Sudden cardiac death
has a much higher incidence in men than women, reflecting sex differences in the
incidence of coronary heart disease as well), as shown in Figure 1. [2,4,13].
Figure 1: A comarisone of SCD for men and wemen.
SCD has many diagnoses:
1) Laboratory studies
a) Cardiac enzymes (creatine kinase, myoglobin, troponin)
b) Electrolytes, calcium, and magnesium
c) Quantitative drug levels (quinidine, procainamide, tricyclic antidepressants,
digoxin): High or low drug levels may have a proarrhythmic effect
d) Toxicology screen: For drugs, such as cocaine, that cause vasospasm-induced
ischemia
e) Thyroid-stimulating hormone
f) Brain natriuretic peptide (BNP)
2) Other tests to evaluate or predict risk of SCD
a) Imaging studies: Chest radiography, echocardiography, nuclear scintigraphy
b) Electrocardiography (ECG): Including, possibly, signal-averaged ECG
c) Coronary angiography
d) Electrophysiology [9].
In general, advanced cardiac life support (ACLS) guidelines should be followed in all
cases of sudden cardiac arrest (SCA).
1. Bystander cardiopulmonary resuscitation (CPR)
Immediate chest compression and defibrillation are reportedly the most important
interventions to improve the outcome in SCA. Research indicates that bystander use of
automated external defibrillators increases neurologically intact survival to discharge (14.3%
without bystander defibrillation; 49.6% with defibrillation).
2. Pharmacologic therapy
Medications used in SCD include the following:
 Ventricular arrhythmia: Epinephrine or vasopressin; amiodarone and lidocaine can be used
as antiarrhythmic drugs if defibrillation does not control the arrhythmia
 Pulseless electrical activity (PEA): Epinephrine; atropine used in case of bradycardia
 Asystole: One study suggested that vasopressin is more effective in acute therapy for
asystole than epinephrine
 Medical stabilization: Empiric beta blockers are reasonable in many circumstances
 Therapeutic hypothermia
This intervention limits neurologic injury associated with brain ischemia during a
cardiac arrest and reperfusion injury associated with resuscitation.
3. Surgery
 Temporary cardiac pacing
 Radiofrequency ablation
 Cardioverter defibrillator therapy
 Coronary artery bypass grafting (CABG)
 Excision of ventricular tachycardia foci
 Excision of left ventricular aneurysms
 Aortic valve replacement
 Orthotopic heart transplantation [10].
Figure 2 shows the surgery types.
Figure 2: Surgery types
SCD is not Heart Attack but at may occur during the course of a heart attack. A heart
attack is caused by the sudden blockage of a heart artery, which may lead to sudden cardiac
death. A person may be at the risk of SCD, if he has the following reasons:
 A family history of unexplained death (including cot death) in people under 35 years old.
 Breathlessness on effort.
 Chest pain on effort.
 Dizziness, fainting and blackouts of unknown cause
 Fast heart rate that comes and goes, even when you are resting.
 Palpitations (arrhythmia) due to an irregular heart rhythm.
An important think, if there is any of these symptoms; one should visit to the
doctor. Investigations for possible heart problems include:
 Medical examination including questions about your family’s medical history.
 ECG (electrocardiogram) and possibly an Echo (echocardiogram) if indicated. These tests
are painless and non-invasive.
 Other more specialised tests may be needed such as a magnetic resonance intensifier
Most of the conditions which cause sudden cardiac death can be treated. It is notice that
a 100 or more people under 35 years die on the island of Ireland each year from sudden
cardiac death. Also athletes & non-athletes are at risk [6].
Taking part in sport does not cause SCD, sport and physical activity is good for the
heart. However; if a person has a serious, undetected heart problem, over-exertion during
sport can act as a trigger for sudden cardiac arrest and possible death in part possibly by
increasing platelet adhesiveness and aggregability, moderate physical activity may be
beneficial by decreasing platelet adhesiveness and aggregability [1,5].
The chain of survival has four links that need to be made quickly to give the best chance
of survival:
1) Get help, call ambulance.
2) Perform CPR, which helps pump blood to the brain & other body organs.
3) Defibrillation with an automated external defibrillator (AED) delivers an electric
shock to the heart if indicated by the rhythm that the defibrillator reads from the
heart via the paddles placed on the chest. This is the only action that can restore a
normal heartbeat rhythm.
4) Advanced care by a medical team [8].
References
1. American Heart Association/Circulation/ Clinical Cardiology: New Frontiers/
Sudden Cardiac Death/Douglas P. Zipes, MD ; Hein J. J. Wellens, MD/Activity/ Sudden
Cardiac Death/ Does taking part in sport cause SCD.
2. American Heart Association/Circulation/ Clinical Cardiology: New Frontiers/
Sudden Cardiac Death/Douglas P. Zipes, MD ; Hein J. J. Wellens, MD/Sudden Cardiac
Death/ Risk Factors of Sudden Cardiac death .
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9. Medscape/Sudden Cardiac Death/ Ali A Sovari, MD, FACP; Chief Editor:
Jeffrey N Rottman, MD/ Diagnosis .
10. Medscape/Sudden Cardiac Death/ Ali A Sovari, MD, FACP; Chief Editor:
Jeffrey N Rottman, MD/ Management .
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Jeffrey N Rottman, MD/ Signs and symptoms .
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Jeffrey N Rottman, MD/ Specific factors relating to cardiovascular disease .
13. Webmd /heart-disease/guide/suddencardiacdeath/ Risk Factors of Sudden
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