emt: cardiac study guide

• Steps of blood flowing through the heart

  1. Blood enters the heart through the superior vena cava and inferior vena cava

  2. Blood enters the right atrium, which is the first chamber of the heart

  3. Blood then goes through the tricuspid valve and into the right ventricle

  4. The right ventricle then pushes blood into the pulmonary valve through either of the pulmonary arteries

  5. The pulmonary arteries empty blood into the lungs to get oxygenated and get rid of the carbon dioxide

  6. Blood goes into the right and left pulmonary veins and into the left atrium

  7. Blood then passes through the mitral valve to get into the left ventricle

  8. Blood gets pushed out of the left ventricle and goes through the aorta into the rest of the body
• Layers of the Heart Tissue

  • Pericardium (pericardial sac) + (outer layer)
  • Epicardium (one of two layers of the pericardium) + (the innermost layer of the pericardium layer of the heart)
  • Myocardium (muscular tissue) + (Performs the function of pumping what is necessary for the circulation of the blood) +(The most massive part of the heart)
  • Endocardium (innermost layer) + (smooth) + (keeps blood from sticking to the inside of the heart)
• CPR for Adults

  Perform 30 high-quality compressions to a depth of 2 inches to 2.4inches (5cm-6cm) at the rate of 100-120 bpm
• CPR for Infants

  Using two fingers, compress the sternum at least one-third of the anterior-posterior diameter of the chest (approximately 1.5 inches/4 cm) at 100-120 bpm
• Ventricular Tachycardia: rapid heart rhythm, usually at a rate of 150-200 bpm.

  • The electrical activity starts in the ventricle instead of the atrium
  • This rhythm does not allow for adequate time between beats for the left ventricle to full with blood → pt’s BP may fall and the pulse may be lost all together
  • The pt may feel weak or light-headed 
  • May even become unresponsive
  • In some cases, existing chest pain may worsen, or chest pain that was not there before the onset of the dysrhythmia may develop
  • pVT will be sustained and may deteriorate into V Fib
• Ventricular Fibrillation:

  • Disorganized, ineffective quivering of the ventricles
  • No blood is pumped through the body, and the patient usually becomes unconscious within seconds
  • The only way to convert this dysrhythmia is to defibrillate the heart
  • Defibrillation is highly successful in terms of saving a life (if delivered within the first few minutes of sudden death)
• Cardiac Rhythms Commonly Associated with Cardiac Arrest

  Tachycardia

  Bradycardia

  Ventricular Tachycardia

  Ventricular Fibrillation
• Pulseless ventricular tachycardia or ventricular fibrillation are cardiac rhythms that an AED will shock. Pulseless electrical activity, or asystole are shockless cardiac rhythms.
• Pulseless electrical activity: refers to a state of cardiac arrest that exists despite an organized electrical complex

  Asystole: flatline, indicating NO ELECTRICAL activity remaining
• If, during the primary, typically, the patient is experiencing dyspnea (SOB) or has an oxygen saturation lower than the normal 94% an EMT may administer oxygen.  
• Aspirin prevents platelets from further adding to each other because it makes them slippery. 
• Aspirin

  Indications

  • chest pain from cardiac origin
• Aspirin

  Side Effects

  • Vomiting
  • Nausea
  • Stomach pain
  • Bleeding
• Aspirin

  Contraindication

  • GI Bleeds
  • Hypersensitivity
• Nitroglycerin is a vasodilator (relaxes the muscles around the vessels and reduces the o2 demand of the heart)
• Nitroglycerin

  Indications

  • chest pain from cardiac origin
• Nitroglycerin

  Side Effects

  • Headache
  • Nausea
  • Hypotension
• Nitroglycerin

  Contraindications

  • Hypersensitivity
  • Phosphodiesterase inhibitor within the past 24 hours
  • Systolic pressure below 100 mmHg
• Systole: when the heart contracts

  Diastole: when the heart relaxes
• A patient suffering from an MI may show the following signs/symptoms:

  1. Sudden onset of weakness, nausea, and/or sweating without cause
  2. Chest pain/discomfort that is “squeezing” or “crushing” and does not change between breaths
  3. Pain radiating to lower jaw, arms, back, abdomen, or neck
  4. Irregular heartbeat & syncope 
  5. Tachycardia
  6. Hypotension
  7. Dyspnea
  8. Pink frothy sputum → pulmonary edema
  9. Sudden death
• The following are common risk factors for an MI

  1. Cigarette smoking
  2. High blood pressure
  3. Elevated cholesterol level
  4. Elevated blood glucose level (diabetes)
  5. Lack of exercise
  6. Obesity
  7. Genetics
  8. Older age
  9. Family history of atherosclerotic coronary artery disease
  10. Race
  11. Ethnicity
  12. Male sex
  13. Stress
  14. Excessive alcohol 
  15. Poor diet
• Acute coronary syndrome is used to describe the symptoms of myocardial ischemia. It is a term for a group of conditions that suddenly stop or severely reduces blood from flowing to the heart muscles. 
• Stable Angina

  • Occurs when doing physical exertion
  • Does not come as a surprise
  • Relieved by rest or medication
• Unstable Angina

  • Occurs while at rest
  • Comes as a surprise
  • Is NOT relieved by medication or rest
• Aortic Dissection/Dissecting Aortic


  A serious condition where the inner layer of the aorta, the large blood vessel branching off the heart, tears. This causes the inner and middle layers of the aorta to separate.
• If the blood-filled channel ruptures through the outside aortic wall

  Aortic dissection is often fatal
• Symptoms of aortic dissection


  • Sudden severe chest or upper back pain (often described as tearing, ripping, or shearing sensation) that radiates to the neck or down the back
  • Sudden severe abdominal pain
  • Loss of consciousness
  • Shortness of breath
  • Sudden difficulty speaking
  • Loss of vision
  • Weakness or paralysis on one side of the body
  • Weak pulse in one arm or thigh compared to the other
  • Leg pain
  • Difficulty walking
  • Leg paralysis
• Thoracic/Acute Aortic Aneurysm


  Also known as aortic dissection
• A patient suffering from angina pectoris may present with the following signs and symptoms:

  1. Anginal pain 
  2. Felt mid-portion of the chest
  3. Can radiate to the jaw and arms
  4. Pain can last about 3-8 minutes (no more than 15 minutes)
  5. May be associated with SOB, nausea, or sweating
• A patient suffering from cardiac tamponade may present with the following signs and symptoms:

  1. Anxiety and restlessness
  2. Low blood pressure
  3. Weakness
  4. Chest pain radiating to your neck/shoulder/back
  5. Rapid breathing
  6. Discomfort that is relieved by sitting or leaning forwards
  7. Fainting, dizziness, and lost of consciousness
• Cardiac Tamponade signs and symptoms can be simplified to Beck's Triad

  1. Jugular vein distension (JVD)
  2. Muffled heart sounds
  3. Hypotension (low bp)
• COPD affects your lungs and CHF affects your heart
• Congestive Heart Failure


  A disorder in which the heart loses part of its ability to effectively pump blood, usually as a result of damage to the heart muscle and usually resulting in a backup of fluid into the lungs
• Congestive Heart Failure


  • Easier to breathe when sitting up
  • More blood returns to the right ventricle and lungs when lying down, causing further pulmonary congestion
  • Agitated
  • Chest pain may or may not be present
  • Distended neck veins that do not collapse EVEN when the patient is sitting
  • Swollen ankles from dependent edema (backup of fluid)
  • High BP
  • Rapid heart rate
  • Rapid respirations
  • Using accessory breathing muscles of the neck and ribs
  • Skin will be pale or cyanotic and sweaty
  • Rales/Crackles
• Signs and symptoms of a patient suffering from cardiogenic shock

  • Anxiety or restlessness as the brain becomes relatively starved for oxygen
  • Air hunger: Patient SAYS that they can not breathe → they obviously can, but the brain senses that it is not getting enough oxygen
  • Pale, cool, clammy skin parameters
  • Pulse rate will be high
  • Rapid and shallow breathing
  • Nausea and vomiting
  • Decrease in body temperature
  • BP will fall --> systolic > 90 mmHg = late stage shock
• Left-Sided Heart Failure

  • Reflective of blood that backs up in the lungs and causes pulmonary edema
  • These include 
  • exertional dyspnea
  • paroxysmal nocturnal dyspnea
  • orthopnea (dyspnea while lying down)
  • hemoptysis (coughing up blood)
• Right-Sided Heart Failure

  • Reflective of blood that backs up in the systemic circulation
  • These include 
  • Jugular venous distention
  • Abdominal distention
  • Irregular pulse → indicates the presence of a cardiac dysrhythmia, which could be present with left OR right heart failure
• Hypertensive Crisis: an emergency situation caused by excessively high BP which can lead to serious complications such as a stroke or an aneurysm. This can present with the following signs and symptoms:

  1. Usually occurs with a systolic pressure of 180+ mmHg
  2. Sudden and severe headache
  3. Cerebral hemorrhage
  4. Strong bounding pulse
  5. ringing in ears
  6. Nausea/Vomting
  7. Dizziness
  8. Warm skin (dry or moist)
  9. Nosebleed
  10. Altered mental status
  11. Sudden development of pulmonary edema

  * Untreated hypertensive emergencies could lead to a stroke or a dissecting aortic

    aneurysm