Sudden

Sudden Cardiac Arrest

Sudden Cardiac Arrest (SCA) is a critical medical emergency characterized by the abrupt loss of heart function, breathing, and consciousness. It is a leading cause of death and requires immediate medical intervention to prevent fatal outcomes.

Pathophysiology

Sudden cardiac arrest occurs when the heart's electrical system malfunctions, leading to an irregular heartbeat (arrhythmia). The most common arrhythmia associated with SCA is ventricular fibrillation, where the heart's ventricles quiver ineffectively instead of pumping blood. This results in the cessation of blood flow to the brain and other vital organs.

Causes

Several factors can precipitate sudden cardiac arrest, including:

• Coronary artery disease: The most common cause of SCA, where the arteries supplying blood to the heart become narrowed or blocked.
• Cardiomyopathy: A disease of the heart muscle that can lead to heart failure and arrhythmias.
• Congenital heart defects: Structural problems with the heart present from birth.
• Electrolyte imbalances: Abnormal levels of potassium, magnesium, or calcium can affect heart rhythm.
• Drug abuse: Use of certain drugs, such as cocaine or amphetamines, can trigger SCA.

Symptoms

Sudden cardiac arrest often occurs without warning. However, some individuals may experience symptoms such as:

• Chest pain
• Shortness of breath
• Weakness
• Palpitations
• Loss of consciousness

Diagnosis

Diagnosis of SCA is primarily clinical, based on the sudden collapse and absence of a pulse. Further evaluation may include:

• Electrocardiogram (ECG): To identify arrhythmias.
• Echocardiogram: To assess heart structure and function.
• Blood tests: To check for electrolyte imbalances or cardiac biomarkers.

Treatment

Immediate treatment is crucial for survival and includes:

• Cardiopulmonary resuscitation (CPR): To maintain blood flow to the brain and organs.
• Defibrillation: Use of an automated external defibrillator (AED) to restore normal heart rhythm.
• Advanced cardiac life support (ACLS): Includes medications and advanced airway management.

Prevention

Preventive measures for those at risk of SCA include:

• Implantable cardioverter-defibrillator (ICD): A device implanted in the chest to detect and correct arrhythmias.
• Lifestyle modifications: Such as diet, exercise, and smoking cessation.
• Medications: To manage underlying heart conditions and reduce arrhythmia risk.

Prognosis

The prognosis for sudden cardiac arrest depends on the speed and effectiveness of treatment. Survival rates improve significantly with prompt CPR and defibrillation.

Also see

• Heart attack
• Ventricular tachycardia
• Coronary artery disease
• Cardiopulmonary resuscitation

Cardiovascular disease A-Z

Most common cardiac diseases

• Cardiac arrhythmia‎
• Cardiogenetic disorders‎
• Cardiomegaly‎
• Cardiomyopathy‎
• Cardiopulmonary resuscitation‎
• Chronic rheumatic heart diseases‎
• Congenital heart defects‎
• Heart neoplasia‎
• Ischemic heart diseases‎
• Pericardial disorders
• Syndromes affecting the heart‎
• Valvular heart disease‎

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

• Accelerated idioventricular rhythm
• Acute decompensated heart failure
• Arteriosclerotic heart disease
• Athletic heart syndrome
• Atrial flutter
• Atrioventricular fistula
• Cardiovascular disease in Australia
• Autoimmune heart disease

B

• Brown atrophy of the heart

C

• Ebb Cade
• Cardiac allograft vasculopathy
• Cardiac amyloidosis
• Cardiac asthma
• Cardiac tamponade
• Cardiogenic shock
• Cardiogeriatrics
• Cardiorenal syndrome
• Cardiotoxicity
• Carditis
• Coronary artery aneurysm
• Coronary artery anomaly
• Coronary artery disease
• Spontaneous coronary artery dissection
• Coronary artery ectasia
• Coronary occlusion
• Coronary steal
• Coronary thrombosis
• Coronary vasospasm
• Cœur en sabot
• Coxsackievirus-induced cardiomyopathy

D

• Duke Treadmill Score
• Duroziez's disease

E

• Eisenmenger's syndrome
• Embryocardia
• Endocardial fibroelastosis
• Eosinophilic myocarditis

H

• Heart attack
• Heart failure
• Heart failure with preserved ejection fraction
• Heart to Heart (1949 film)
• High-output heart failure
• Hyperdynamic precordium

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

I

• Idiopathic giant-cell myocarditis
• Interventricular dyssynchrony
• Intraventricular dyssynchrony
• Isolated atrial amyloidosis

K

• Keshan disease

L

• Loeffler endocarditis

M

• Mydicar
• Myocardial bridge
• Myocardial disarray
• Myocardial rupture
• Myocardial scarring
• Myocardial stunning
• Myocarditis

N

• Nonbacterial thrombotic endocarditis

O

• OLR1
• Ostial disease

P

• Papillary fibroelastoma
• Pathophysiology of heart failure
• Postpericardiotomy syndrome
• Pulmonary vein stenosis

R

• Right axis deviation
• Roemheld syndrome

S

• Saturated fat and cardiovascular disease
• SCAR-Fc
• Shone's syndrome
• Strain pattern
• Subacute bacterial endocarditis
• Sudden cardiac death of athletes

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

T

• Traumatic cardiac arrest

V

• Ventricular aneurysm
• Vibroacoustic disease
• Viral cardiomyopathy

W

• Waon therapy