What is Cardiac Arrest (Heart Attack)?
Cardiac arrest is a term defined by the American Heart Association and the American College of Cardiology. It refers to the sudden stop of heart activity. When this occurs, the person becomes unresponsive, they don’t breathe normally, and show no signs of their blood circulating through their body. If we don’t take action quickly, this can unfortunately result in a sudden death. It’s important to make sure we don’t use this term for incidents that aren’t fatal. Cardiac arrest typically involves a person being brought back through methods like CPR (a procedure used to help the heart beat again), defibrillation or cardioversion (methods used to correct an irregular heart rhythm), or cardiac pacing (a process that uses a device to change the heart’s rhythm).
Every year, more than 400,000 Americans sadly experience sudden cardiac death. Those who go through cardiac arrest may or may not have been diagnosed previously with heart disease. The reasons behind cardiac arrest change based on the person and their age, but it often happens in people already diagnosed with heart disease. It’s important to note that most cardiac deaths are sudden and usually unexpected – they’ve mainly resulted in death in the past. Nowadays, because of helpful methods like CPR from people nearby and progress in emergency medical services, chances of survival have improved significantly. Despite these advances, only about 10% of those who experience cardiac arrest are able to leave the hospital alive, and a majority of these survivors end up having neurological damage.
What Causes Cardiac Arrest (Heart Attack)?
Cardiac arrest, or when the heart suddenly stops beating, is usually caused by issues with the structure of the heart. Around 70% of cardiac arrest cases are believed to be due to a condition called ischemic coronary disease. This disease is a leading cause of cardiac arrest and happens when the heart’s blood supply is blocked.
Other structural issues that could lead to cardiac arrest include congestive heart failure (when the heart doesn’t pump blood as well as it should), left ventricular hypertrophy (enlarged heart muscle), congenital coronary artery abnormalities (birth defects in the heart’s blood vessels), arrhythmogenic right ventricular dysplasia (a rare type of cardiomyopathy where the heart muscle of the right ventricle is replaced by fat and fibrous tissue causing rhythm problems), hypertrophic obstructive cardiomyopathy (a disease in which the heart muscle becomes abnormally thick), and cardiac tamponade (pressure on the heart caused by fluid in the sac surrounding it).
There are also non-structural heart-related causes such as Brugada syndrome, Wolf-Parkinson-White syndrome, and congenital long QT syndrome. These are all types of rare, inherited heart rhythm disorders.
On the other hand, there are also many non-heart related causes of cardiac arrest. These can include things like bleeding inside the brain, a blocked lung artery (known as a pulmonary embolism), a pneumothorax (collapsed lung), respiratory arrest (breathing stops), overdoses of toxic substances including drugs, imbalances in body salts or minerals, serious infections, extreme cold (hypothermia), or physical injury.
Risk Factors and Frequency for Cardiac Arrest (Heart Attack)
Occlusive coronary disease, a condition in which the arteries that supply blood to the heart get blocked, is the main reason for heart attacks and sudden heart-related deaths. There is a high rate of sudden death in infants aged up to 6 months due to sudden infant death syndrome. After that, this rate generally stays low until it spikes again between the ages of 45 to 75. It’s interesting to note that the primary cause of heart-related deaths in adolescents and young adults is the same as in middle-aged and older adults. In the US, nearly 70% of all sudden heart-related deaths can be traced back to coronary heart disease.
When comparing younger individuals, women are less likely to experience heart-related deaths than men. However, women, like men, can be at risk due to factors such as raised blood pressure, high blood fat levels, diabetes, smoking, getting older, and having a family history of heart disease.
- Occlusive coronary disease is the number one cause of heart attacks and sudden heart-related deaths.
- Infants up to 6 months old have a high rate of sudden death due to sudden infant death syndrome.
- The rate of sudden death spikes again between the ages of 45 and 75.
- The main cause of heart-related death in young people is the same as in older adults.
- Nearly 70% of all sudden heart-related deaths in the US are due to coronary heart disease.
- Women are less likely to experience heart-related deaths at a younger age than men.
- Both women and men can be at risk due to factors like high blood pressure, high blood fat levels, diabetes, smoking, getting older, and having a family history of heart disease.
Signs and Symptoms of Cardiac Arrest (Heart Attack)
Some people might experience warning signs before a cardiac arrest happens. However, these symptoms might go unnoticed or be disregarded. It’s worth mentioning that many survivors of cardiac arrest often can’t remember the symptoms before the event due to temporary memory loss. Based on the recollections of those who didn’t experience this memory loss, or observations from family members or other witnesses, it has been found that chest pain is the most common warning sign, which aligns with the symptoms of acute heart muscle damage.
If a person is having a cardiac arrest, they will be unresponsive, lack a pulse, and will not be breathing. A prompt full-body check can help inform the necessary treatment measures.
Testing for Cardiac Arrest (Heart Attack)
If someone suffers a heart attack, there’s no need for a lot of blood work or imaging tests. Sometimes, if it’s possible, doctors may check the levels of potassium and glucose in the patient’s blood. Glucose is a type of sugar that our cells use for energy, while potassium is a mineral that helps nerves and muscles communicate. Too much or too little of either can cause problems in the body, including the heart.
Doctors may also use a portable ultrasound machine to look at the heart. This can help them see how the heart is moving. However, this is only helpful if it doesn’t get in the way of the attempt to resuscitate the patient, which is always the priority during a cardiac arrest.
Treatment Options for Cardiac Arrest (Heart Attack)
When a person suffers cardiac arrest, their heart suddenly stops beating. Restoring their heartbeat and circulation early is critical. This can be achieved with early CPR (cardiopulmonary resuscitation) and the use of a device called a defibrillator.
First, it’s important to identify if someone is in cardiac arrest. Signs include not responding when spoken to or shaken gently, lack of pulse, and not breathing normally. If these signs are present, immediate CPR should be started, and emergency services should be called.
Public access defibrillators (AEDs) are becoming more common in places like schools, shopping centers, and airports. If one is available, it should be used as quickly as possible.
Depending upon the skills of the rescuer, treatment could vary:
Lay Rescuer (ordinary people): The lay rescuer can perform hands-only CPR, and use an AED if available. If the person has had a drowning episode, they can attempt two rescue breaths.
Basic Life Support (trained people): If trained, these people can add in breaths during CPR and use airway maneuvers and devices for better ventilation of the lungs.
Advanced Life Support (professionals): Healthcare professionals trained in advanced life support can add in some medications like Epinephrine and Amiodarone, along with advanced airway devices, to their treatment.
Physician (Medical doctors): Physicians can take their initial approach further based on the cause of the cardiac arrest.
Medical: In medical arrest, the patient may be put on an ECMO (Extracorporeal Membrane Oxygenation) machine that oxygenates the blood until the heart function is restored.
Trauma: Patients of traumatic cardiac arrest can have different treatments based on the cause (blunt or penetrating trauma). Blunt trauma (like from a motor vehicle accident) often causes severe internal injuries. Penetrating trauma patients (like from a gunshot wound) are usually treated with ways to decompress ‘air’ from the chest cavity. If the patient’s condition doesn’t improve, they could undergo a procedure to open the chest cavity to locate and treat the injuries directly. A technique still under evaluation involves the use of a device that blocks the aorta to control bleeding.
The ultimate aim of all these treatments is to get the heart to start beating again, a condition known as return of spontaneous circulation (ROSC). Once this happens, post-resuscitation care, as well as long-term management starts to help improve the patient’s condition.
What else can Cardiac Arrest (Heart Attack) be?
Syncope, also known as fainting, is a brief loss of consciousness caused by the brain not getting enough blood. People who faint are unresponsive for a short time, similar to those having a cardiac arrest. However, unlike people experiencing a cardiac arrest, those who faint still breathe normally and have a pulse. This difference helps doctors distinguish between fainting and cardiac arrest.
Another condition that might be confused with cardiac arrest is a seizure. During a seizure, the person will also be unresponsive and might have irregular breathing. But unlike a cardiac arrest, the individual still has a pulse and exhibits rhythmic activity, allowing doctors to tell the difference.
Also, an overdose, especially from opioids, can cause someone to become unresponsive and have abnormal breathing. Again, the presence of a pulse can help confirm this situation is an overdose rather than a cardiac arrest.
What to expect with Cardiac Arrest (Heart Attack)
Survival rates after a cardiac arrest are significantly improved if the event is witnessed and immediate CPR is performed. When needed, using a defibrillator can also greatly increase chances of recovery. According to research, younger and healthier individuals are more likely to recover than elderly individuals or those with multiple health conditions.
Moreover, individuals who experience penetrating injuries have a higher survival rate compared to those who experience a blunt force trauma. Interestingly, some studies haven’t found a clear benefit of advanced life support measures in cardiac arrest, like using a tube to help with breathing (endotracheal intubation) or giving medication intravenously (through a vein).
Possible Complications When Diagnosed with Cardiac Arrest (Heart Attack)
During a cardiac arrest, a number of complications can arise. The most serious problem, although rare, is failure of the AED (automated external defibrillator) – this machine is used to try to shock the patient’s heart back into a normal rhythm. Other complications include the inability to obtain IV or IO access – necessary for giving important medications. After the return of spontaneous circulation (ROSC), the failure to secure or maintain a device for breathing could lead to another cardiac arrest. In cases of cardiac arrest caused by trauma, incorrect positioning of needle thoracotomy or pericardiocentesis (procedures to relieve pressure buildup) could also cause complications.
- AED failure
- Inability to access veins or bone marrow for medication delivery (IV/IO access)
- Failure to secure or maintain a device for breathing after ROSC
- Incorrect positioning of procedures to relieve pressure buildup in trauma cases
Recovery from Cardiac Arrest (Heart Attack)
If someone’s heartbeat returns to normal after a cardiac arrest, doctors then need to decide if and when to use a technique called targeted temperature management. This method is best used for patients who had a medical reason for their cardiac arrest, are still unresponsive, but are stable. The use of targeted temperature management has been proven to reduce death rates and help maintain brain function in these conditions.
Once a patient’s heart condition has stabilized, doctors then check their breathing. If the patient can’t be safely removed from mechanical ventilation, an operation called a tracheostomy can be done to make sure they have a clear airway. To make sure the patient is getting proper nutrition, a tube called a percutaneous endoscopic gastrostomy (PEG) tube is usually inserted.
Those who needed a tracheostomy and a PEG tube will likely have a long recovery period ahead. These patients are typically moved to long-term acute care (LTAC) facilities to continue healing and undergoing rehabilitation. Even if the patient can safely come off mechanical ventilation, they will likely still require a significant recovery period, but they generally have more physical abilities.
Preventing Cardiac Arrest (Heart Attack)
Most heart attacks happen outside of a hospital. Swiftly starting CPR (Cardiopulmonary Resuscitation, a life-saving emergency procedure done when the heart stops beating) and using an AED (Automated External Defibrillator, a device that restores a normal heartbeat) have been shown to significantly help patients’ chances of survival. That’s why training people to be able to perform CPR can be a lifesaver.
Yet, even with proper training, some people are still hesitant to do CPR on someone in need. This might be because they’re not sure if the person has had a heart attack, they don’t feel encouraged, or they’re not confident in their skills. There could also be situations where the patient is out of reach or can’t be moved, making it challenging for the person to do their best in performing CPR.
