Chapter 16: Cardiovascular Emergencies Flashcards
Path of impulses in the heart
Brain, SA node, atria, AV node, bundle of His, Purkinje fibers, ventricles
Automaticity
Feature of cardiac muscle that allows cells to contract without a nerve source.
Stroke volume
Amount of blood ejected by each ventricular contraction
Cardiac output
Volume of blood going through the circulatory system in one minute. SV times heart rate.
Subclavian arteries
Supply blood to upper extremities, branch into brachial arteries
Descending aorta
Divides into right and left iliac arteries at the umbilicus. As they enter the legs, they branch into femoral arteries, which branches into anterior and posterior tibial arteries at knee level.
3 components of perfusion
Heart, blood vessels, blood
Tachycardia
Doesn’t allow enough time for heart to refill completely
Ischemia
Decreased blood flow. Often a cause of chest pain.
Infarction
Death of tissue
Occulism
Blockage
Lumen
Inside diameter of artery
Atherosclerosis
- Calcium and cholesterol build up and form blockages in vessels. Eventually forms an occulism.
- Plaque can develop a crack, which activates blood clotting. Blocks lumen of artery or forms a thromboembolism which causes hypoxia below it.
- Blockage in a coronary artery is an AMI
Atherosclerosis risk factors
Smoking, high blood pressure, high cholesterol, high blood glucose, obesity, older age, family history, sex (male).
Acute Coronary Syndrome
- Describes a group of symptoms caused by myocardial ischemia.
- Angina pectoris- chest pain from lack of oxygen, symptom of acute coronary artery disease. Lasts less than 15 minutes. Crushing pain under sternum, radiating to jaw, arm, back, abdomen, nausea, sob
AMI Symptoms
Sudden onset of weakness, nausea, and sweating without an obvious cause. Chest pain or pressure that is crushing/squeezing and does not change with each breath. Pain or pressure in lower jaw, abdomen, or neck. Shortness of breath, irregular heartbeat, syncope, nausea, pink frothy sputum. In older people or women, most common symptom could be fatigue or nausea.
Ventricular tachycardia
Heart rate is 150-200 bpm. Electrical activity starts in ventricles and doesn’t allow the left ventricle to fill with blood. Blood pressure falls and pulse can be lost.