The heart is a muscular organ that functions like a pump. It is located in the center of the chest between the lungs, protected by the sternum and rib cage in front and by the spinal column in the back. The heart consists of four chambers and is separated into right and left halves.
The right side of the heart has two chambers known as the right atrium and the right ventricle. Oxygen-depleted blood from the veins enters the right atrium and then passes to the right ventricle, which pumps the blood to the lungs to release waste products and absorb oxygen. The oxygen-rich blood then returns to the heart where it enters the left atrium and passes to the left ventricle, where it is pumped to all parts of the body.
An electrical system within the heart triggers the pumping action of the heart muscle. During the average lifetime, the heart will beat nearly 3 billion times and will pump about 40 million gallons of blood. If your heart beats 70 times per minute, that is more than 100,000 beats per day.
As blood flows through the arteries, oxygen and nutrients, such as glucose, are delivered to cell throughout the body. Then, as blood flow through the veins, carbon dioxide and other wastes are taken away. This ongoing, continuous process is called perfusion.
The primary gases exchanged are oxygen and carbon dioxide. All cells require oxygen to function. In addition, cells also require energy to function. Glucose, a simple sugar molecule, is the main source of energy carried by the blood for the cells.
Cardiovascular disease is an abnormal condition that affects the heart and blood vessels. An estimated 80 million Americans suffer from some form of the disease. It is the number one killer in the United States, and a major cause of disability.
The most common conditions caused by cardiovascular disease are:
Other specific cardiovascular emergencies include:
- Angina pectoris (AHA)
- Arrhythmias (AHA)
- Atrial fibrillation (AHA)
- Heart failure (AHA)
- Hypertension (AHA)
Assessment of Cardiac Emergencies
The sooner you recognize the signs and symptoms of a heart attack and act, the better chance you have to save a life. Some people deny they are having a heart attack, while others may collapse without displaying any signs whatsoever. While it is fairly obvious to call EMS when a patient suddenly collapses, you must also call EMS if the patient shows some or all of the following signs and symptoms:
- Persistent discomfort, pressure, or pain in the chest
- Radiating pain from the chest to the shoulder, arms, neck, jaw, stomach, or back
- Pain that comes and goes or that lasts longer than 3-5 minutes
- Difficulty breathing, shortness of breath, or noisy breathing
- Pale, ashen skin
- Feeling lightheaded, dizzy, or nauseated
Diabetes can affect the nerves making it less likely that the patient will experience heart attack symptoms. This is called a “silent heart attack.” Elderly patients often lose pain perception and can experience silent heart attacks as well.
Although women may experience chest pain or discomfort during a heart attack, they are more likely to experience other signals, including shortness of breath, nausea, vomiting, stomach pain, back pain, jaw pain, and unexplained fatigue. When they do experience chest pain, it is often atypical pain: sudden, sharp, but short-lived pain. As a result, women often delay telling others about their symptoms to avoid worrying them.
Caring for Heart Attack and Other Cardiac Emergencies
If you think someone is having a heart attack, take immediate action.
- Call EMS
- Have the person stop all activity and rest
- Loosen any tight or uncomfortable clothing
- Closely monitor the patient until EMS personnel arrive. Note any changes in the patient’s appearance and behavior, and be prepared to perform CPR or use an AED
- Comfort and reassure the patient
- If medically appropriate and local protocols allow, give aspirin if the patient can swallow and has no known contraindications.
- Assist with any medicine prescribed to the patient
- Administer oxygen , if available
When the heart stops or beats too ineffectively to generate a pulse, the patient is said to have suffered cardiac arrest. The body cannot survive long in this condition. A person in cardiac arrest is not breathing and has no pulse. Cardiac arrest can happen suddenly without any of the warning signs usually seen in a heart attack. This is known as sudden cardiac arrest (SCA), which accounts for more than 300,000 deaths annually in the United States. SCA is caused by abnormal, chaotic electrical activity of the heart, such as ventricular fibrillation (V-fib).
- Cardiac chain of survival
- Clinical vs. biological death
- Pulseless arrhythmias/algorithms
- Sudden cardiac arrest
Assessment of Cardiac Arrest
- CAB and ABC rationales (For more info, go to CPR Advisories)
- Primary assessment
- Compression-only CPR
- One-rescuer CPR
- Two-rescue CPR
- High-Quality CPR
- Complications of CPR