Overview

Sudden Cardiac Arrest (SCA) refers to the abrupt halt of all heart activity due to an irregular heart rhythm. As a consequence, the heart fails to pump blood, depriving organs and the entire body of essential oxygen. Without a continuous supply of oxygen delivered through the bloodstream, vital organs may cease to function within minutes, leading to rapid deterioration and potential death.

During this situation, the cessation of heart activity in sudden cardiac arrest results in the cessation of breathing as wellThe individual loses consciousness as a result.

Sudden cardiac arrest might result in mortality if it is not treated right away. Cardiopulmonary Resuscitation (CPR) and shocks to the heart delivered by an Automated External Defibrillator (AED) are emergency treatments for sudden cardiac arrest. With prompt, effective medical care, survival is feasible.

A heart attack is not the same as a sudden cardiac arrest. When blood flow to a portion of the heart is blocked, a heart attack occurs. There is no obstruction to account for sudden cardiac arrest. However, a heart attack can alter the electrical activity of the heart, which might result in a sudden cardiac arrest.

Symptoms

The following are immediate and severe symptoms of sudden cardiac arrest:

  • No breathing
  • Passing out unexpectedly
  • Absence of pulse
  • Abrupt collapse

Prior to sudden cardiac arrest, other symptoms can occasionally appear. These could consist of:

  • Weakness
  • Difficulty of breathing
  • Discomfort in the chest
  • Palpitations, which are rapid heartbeats, fluttering, or hammering heart

But sudden cardiac arrest frequently happens without any prior warning.

The shortage of oxygenrich blood when the heart stops can quickly result in death or irreversible brain damage.

For any of the following symptoms, dial your emergency medical services:

  • Discomfort or pain in the chest.
  • Feeling like you are going to faint.
  • Losing of consciousness.
  • Dizziness.
  • Sudden wheezing.
  • Difficulty of breathing.
  • Pounding heartbeat.
  • Irregular or rapid heart rate.

If you come across someone who is unresponsive and not breathing, it is crucial to immediately call your local emergency services. Simultaneously, initiate CPR (Cardiopulmonary Resuscitation) as recommended by the American Heart Association. CPR involves performing forceful and rapid chest compressions to help circulate blood and deliver oxygen to the vital organs. If an automated external defibrillator (AED) is accessible, promptly utilize it as well.

How to do CPR

If the victim is not breathing, perform CPR. About 100 to 120 quick, forceful pushes on the person’s chest should be applied per minute. Check the person’s airway if you are trained in CPR. Then after every 30 compressions, give rescue breaths.

Just keep performing chest compressions if you are untrained. Permit the chest to fully rise in between compressions. Continue doing this until an AED is available or help arrives.

Automated External Defibrillators (AEDs), are portable devices that can be used in a variety of public settings, including malls and airports. One can also be purchased for use at home. Voice instructions with stepbystep directions are included with AEDs. They are configured to only permit a shock when necessary.

Causes

Sudden cardiac arrest is brought on by a shift in the electrical activity of the heart. The heart ceases to pump blood as a result of the alteration. The body receives no blood flow.

How the heart beats

Understanding the heart’s signaling system may be helpful in understanding sudden cardiac arrest.

The heart’s electric signals regulate the heartbeat’s rhythm and rate. Electrical signals that are incorrect or extraneous can cause the heart to beat excessively quickly, too slowly, or incoherently. Arrhythmias are variations in heartbeat. A few arrhythmias are shortlived and safe. Others may result in a sudden cardiac arrest.

Heart disorders that may cause a sudden cardiac arrest

Ventricular fibrillation, a heart rhythm disorder, is the most typical cause of sudden cardiac arrest. The lower heart chambers quiver ineffectively as a result of rapid, irregular cardiac signals rather than pumping blood. You may be more susceptible to developing this kind of cardiac issue if you have certain heart issues.

However, even those without a documented heart condition might experience sudden cardiac arrest.

The following heart disorders can result in sudden cardiac arrest:

  • Coronary artery disease. If the heart arteries are blocked with cholesterol and other deposits, decreasing blood flow to the heart, sudden cardiac arrest may happen.
  • Heart attack. A heart attack, which is frequently caused by severe coronary artery disease, can result in ventricular fibrillation and sudden cardiac arrest. Additionally, a cardiac attack may leave scar tissue there. The heartbeat may alter as a result of the scar tissue.
  • Enlarged heart called cardiomyopathy. The most common cause of this illness is stretching of the heart muscle’s inner walls. The heart muscle increases in size or thickness.
  • Heart valve disease. Stretching or thickening of the heart muscle may result from leaking or constriction of the heart valves. There is a higher chance of developing a cardiac rhythm issue when the chambers enlarge or weaken as a result of pressure from a tight or leaking valve.
  • Congenital heart defect. When a child or adolescent experiences a sudden cardiac arrest, their underlying heart condition is frequently to blame. Sudden cardiac arrest is more likely to occur in adults who have had surgery to correct a congenital heart abnormality.
  • Long QT syndrome (LQTS) and other heart signaling problems. The heart beats erratically due to conditions like Brugada syndrome and long QT syndrome. Sudden death may occur if the heart rhythm is not rapidly restored. A sudden death is extremely dangerous for young persons with LQTS.

Risk factors

The risk factors for sudden cardiac arrest are the same as those for heart disease. These consist of:

  • Elevated blood pressure or blood cholesterol
  • History of coronary artery disease in the family
  • Having diabetes
  • Being obese
  • Sedentary lifestyle
  • Smoking

The following are other factors that could raise the risk of sudden cardiac arrest:

  • A history of various types of heart illness, such as heart rhythm issues, heart failure, or congenital heart defects, in oneself or one’s family.
  • A history of sudden cardiac arrest in one’s family or one’s own past episodes.
  • Having heart attack in the past.
  • Obstructive sleep apnea.
  • Chronic kidney disease.
  • Decreased levels of magnesium and potassium.
  • Aging As people get older, their risk of sudden cardiac arrest rises.
  • Gendermale.

Utilizing illicit substances like amphetamines or cocaine.

Diagnosis

Sudden cardiac arrest is an abrupt event that requires immediate emergency care at a hospital. Timely intervention can increase the chances of survival by restoring proper heart function. After stabilization, medical professionals will perform diagnostic tests to determine the underlying cause of the cardiac arrest. These tests help identify the root problem and guide subsequent treatment.

Tests

Tests are conducted to investigate potential heartrelated issues and evaluate the effectiveness of blood pumping by the heart.

Commonly used tests for sudden cardiac arrest are:

  • Blood tests. Following cardiac damage following a heart attack, some heart proteins gradually leak into the circulation. These proteins can be checked for by blood tests. The levels of potassium, magnesium, hormones, and other bodily components that affect the heart’s functionality are measured using further blood tests.
  • Electrocardiogram (ECG or EKG). This short and painless examination examines the heart’s electrical activity. Electrodes, which act as sensors, are frequently attached to  the chest as well as the arms and legs. How quickly or slowly the heart is beating can be determined by an ECG. The test may reveal variations in heartbeat that elevate the risk of unexpected death.
  • Echocardiogram. Sound waves can be visualized as moving heartbeats. This examination can demonstrate the blood flow within the heart and its valves. It can reveal damaged cardiac muscle and issues with the heart valves.
  • Ejection fraction. A measurement obtained during an echocardiography, assesses the volume of blood expelled by the heart with each contraction. Normally, ejection fractions fall within the range of 50% to 70%. However, when the ejection fraction drops below 40%, the risk of sudden cardiac arrest increases.
  • Chest Xray. The heart and lungs’ dimensions and shapes are revealed through this test. Additionally, it might reveal if you have heart failure.
  • Nuclear scan. Normally, a stress test is conducted along with this exam. It aids in the detection of heartrelated blood flow issues. IV injections deliver tracer doses, which are small quantities of radioactive material. When radioactive material passes through the heart and lungs, special cameras can capture the event.
  • Electrophysiology (EP). An EP investigation is a thorough analysis of your heart’s electrical activity. Electrocardiogram (EKG) tracings and electrical measures from inside your heart are made by your healthcare provider using cardiac catheters, which are tiny tubes.
  • Cardiac catheterization. This examination enables medical professionals to spot obstructions in the cardiac arteries. In order to reach the heart, a catheter, which is a long, thin, flexible tube, is placed into a blood vessel, typically in the groin or wrist. Dye passes through the catheter to reach the heart’s arteries. The dye enhances the visibility of the arteries in Xray and video pictures.

During this examination, if a blockage is identified, a procedure called balloon angioplasty can be performed to clear the obstruction. In this procedure, a medical professional may use a stent to keep the artery open and ensure proper blood flow. The stent acts as a support structure, helping to maintain the artery’s patency.

Treatment

One form of treatment for sudden cardiac death is:

  • CPR. To treat sudden cardiac arrest and avoid mortality, CPR must be done right away.
  • Defibrillation (resetting the heart rhythm). If an automatic external defibrillator, or AED, is available, you can use it to perform this. They are widespread in public spaces.
  • Medicines. Treatment for irregular heartbeats and symptom management.
  • Heart procedure or surgery. Implantation of cardiac devices or obstruction treatment.

Doctors do testing in the emergency room to rule out potential causes such a probable heart attack, heart failure, or abnormalities in electrolyte levels. The causes determine the treatments.

Medications

The heart rhythm can be restored with the aid of medications. Antiarrhythmic drugs are the name for these medications.

The following medications may also be used to treat or reduce the risk of sudden cardiac death:

  • Calcium channel blockers.
  • Beta blockers.
  • AngiotensinConverting Enzyme (ACE) inhibitors.

Surgery or other procedures

To address cardiac rhythm issues, clear blockages, or enhance heart function, various medical interventions and therapies may be necessary. These may include:

  • Implantable CardioverterDefibrillator (ICD). Similar to a pacemaker, an ICD is a batteryoperated device that is implanted under the skin close to the collarbone. The heart rhythm is continuously monitored by the ICD. The device shocks the heart to restore rhythm if it detects an abnormal heartbeat. It can stop a heartbeat alteration that could be fatal.
  • Coronary angioplasty. This procedure, also known as percutaneous coronary intervention, clears clogged or obstructed cardiac arteries. It may be carried out concurrently with a cardiac catheterization, a procedure used by medical professionals to identify heart artery narrowing.

A thin, flexible tube is inserted into a blood vessel by a medical professional, typically in the groin, and moved to the obstruction. The tube’s tip has a little balloon that has been enlarged. As a result, the artery is opened, improving hearthealthy blood flow.

The tube may be passed via a stent, a metal mesh tube. The stent keeps the artery open and stays in place.

  • Coronary artery bypass surgery. This procedure, also known as coronary artery bypass grafting or CABG, makes a new passageway for blood to travel through a blocked artery to the heart. The heart’s blood flow is restored as a result.
  • Radiofrequency catheter ablation. The goal of this therapy is to stop a dysfunctional cardiac signaling system. An irregular heartbeat might result from an issue with heart signals. Catheters are thin, flexible tubes that are threaded through blood vessels and into the heart. To make tiny scars in the heart, heat or radiofrequency energy is applied to the catheter’s tip. This blocks the abnormal cardiac signal.
  • Corrective heart surgery. Surgery may be used to treat heart conditions that are congenitally present, heart valve disease, or a sick heart muscle.

Doctors who treat this condition