Ch.17 Cardiovascularemergencies Flashcards
___ has been the leading killer of Americans since 1900
Heart disease
It is important for Ems providers to understand that many deaths caused by ___ disease occur because of problems that may have been avoided by people living more healthful lifestyles and by access to improved medical technology
Cardiovascular disease
A heart attack; death of heart muscles following obstruction of blood flow to it. “Acute” in this context means “new” or “happening right now”
Acute myocardial infarction
A state in which not enough oxygen is delivered to the tissues of the body, caused by low output of blood from the heart. It can be a severe complication of a large acute myocardial infarction, as well as other conditions
Cardiogenic shock
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
A medication that increases cardiac perfusion by causing blood vessels to dilate; EMTs may be allowed to assist the patient to self-administer this medication
Nitroglycerin
A medication that is an antipyretic(reduces fever),analgesic(reduces pain), anti-inflammatory (reduces inflammation ), and a potent inhibitor of platelet aggregation (clumping)
Aspirin
A hollow muscular organ that pumps blood throughout the body
Heart
The heart is divided down the middle into two sides(left and right) by a wall called the
Septum
Each side of the heart has an__, or upper chamber, to receive incoming blood, and a __, lower chamber, to pump outgoing blood.
Atrium
Ventricle
Blood leaves each of the four chambers of the heart through a
One-way valve
The __, the bodys main artery, receives the blood ejected from the left ventricle and delivers it to all the other arteries so they can carry blood to the tissues of the body
Aorta
The main artery leaving the left side of the heart and carrying freshly oxygenated blood to the body
Aorta
The right side of the heart receives _ from the veins of the body
Oxygen-poor (deoxygenated) blood
After contraction if the right ventricle, blood flows into the pulmonary __ and travels through the pulmonary circulation in the lungs, where it is reoxygenated .
Pulmonary artery
The left side of the heart receives __blood from the lungs through the pulmonary veins
oxygen-rich (oxygenated)
Normal electrical impulses begin in the sinus node, which is in the upper part of the right atrium and is also known as the ___
Sinoatrial (SA) node
The impulses travel across both atria, stimulating them to contract. Between the atria and the ventricles, the impulses cross a bridge of special electrical tissue called the_. Here, the signal is slowed for about one- to two-tenths of a second to allow blood time to pass from the atria to the ventricles. The impulses then exit the_ and spread throughout both ventricles via the bundle of His, the right and left bundle branches, and the Purkinje fibers, ultimately causing the muscle cells of the ventricles to contract.
atrioventricular (AV) node
Cardiac muscle cells have a special characteristic called__ that is not found in any other type of muscle cells.
__allows a cardiac muscle cell to contract spontaneously without a stimulus from a nerve source.
automaticity
The stimulus that originates in the SA node is controlled by impulses from the brain, which arrive by way of the_. The___ is the part of the brain that controls the functions of the body that do not require conscious thought, such as the heartbeat, respirations, dilation and constriction of blood vessels, and digestion of food.
autonomic nervous system
The autonomic nervous system has two parts, the___ and the_
the sympathetic nervous system and the parasympathetic nervous system
The__ is also known as the fight-or-flight system and makes adjustments to the body to compensate for increased physical activity. The__ speeds up the heart rate, increases respiratory rate and depth, dilates blood vessels in the muscles, and constricts blood vessels in the digestive system.
sympathetic nervous system
The__ directly opposes the sympathetic nervous system. The__ slows the heart and respiratory rates, constricts blood vessels in the muscles, and dilates blood vessels in the digestive system.
parasympathetic nervous system
The ability of cardiac muscle cells to contract without stimulation from the nervous system
Automaticity
The part of the nervous system that controls the involuntary activities of the body such as the heart rate, blood pressure, and digestion of food
Autonomic nervous system
To perform the function of pumping blood, the __, or heart muscle, must have a continuous supply of oxygen and nutrients
Myocardium
During periods of physical exertion or stress, the myocardium requires more oxygen. The heart must increase__ to meet the increased metabolic requirements of the body.__ is increased by increasing the heart rate or stroke volume.
cardiac output
A measure of the volume of blood circulated by the heart in 1 minute, calculated by multiplying the stroke volume by the heart rate
Cardiac output
In the normal heart, this increased oxygen demand of the myocardium itself is accomplished by increasing the amount of blood flowing (and therefore the amount of oxygen being delivered) to the myocardium by dilation, or widening, of the_. The__ are the blood vessels that supply blood to the heart muscle
coronary arteries
Widening of a tubular structure such as a coronary artery
Dilation
The coronary arteries are the blood vessels that supply blood to the heart muscle. They begin at the first part of the aorta, just above the_.
aortic valve
The__ supplies blood to the right atrium and right ventricle and, in most people, the bottom part, or inferior wall, of the left ventricle.
right coronary artery
The__ supplies blood to the left atrium and left ventricle and divides into two major branches, just a short distance from the aorta.
left coronary artery
The one-way valve that lies between the left ventricle and the aorta and keeps blood from flowing back into the left ventricle after the left ventricle ejects its blood into the aorta; one of four heart valves
Aortic valve
The right and left __ supply the head and brain with blood
Carotid arteries
The right and left __ supply blood to the upper extremities
Subclavian arteries (under the clavicles)
As the subclavian artery enters each arm, it becomes the __, the major vessel that supplies blood to each arm
Brachial artery
Just below the elbow, the brachial artery divides into two major branches: the __ and __ arteries, supply blood to the lower arms and hands
Radial and ulnar arteries
The major __ of the body carry oxygen rich blood to all parts of the body. The major __ of the body carry deoxygenated blood back to the heart
Arteries
Veins
At the level of the umbilicus, the descending aorta divides into two main branches called the right and left __ arteries, which supply blood to the groin, pelvis, and legs
iliac arteries
As the iliac arteries enter the legs through the groin, they become the right and left __ arteries
Femoral
At the level of the knee, the femoral artery divides into the anterior and posterior __ arteries and the __ artery, supplying blood to the lower legs and feet
Tibial arteries
Peroneal artery
After blood travels through the arteries, it enters smaller and smaller vessels called __ and eventually enters the capillaries
Arterioles
__are tiny blood vessels about one cell thick that connect arterioles to venules.__, which are found in all parts of the body, allow the exchange of nutrients and waste at the cellular level. As the blood passes through the__, it gives up oxygen to the tissues and picks up carbon dioxide and other waste products to be removed from the body
Capillaries
The small blood vessels that connect arterioles and venules; various substances pass through capillary walls, into and out of the interstitial fluid, and then on to the cells
Capillaries
__are the smallest branches of veins. After traveling through the capillaries, oxygen-poor blood enters the system of veins, starting with the_, on its way back to the heart. The veins become larger and larger and eventually form the two large venae cavae: the superior vena cava and the inferior vena cava.
Venules
The__ vena cava carries blood from the head and arms back to the right atrium. The__ vena cava carries blood from the abdomen, pelvis, and legs back to the right atrium. The superior and inferior venae cavae join at the right atrium of the heart, where blood is then returned into the pulmonary circulation for oxygenation.
superior (upper)
inferior (lower)
__are the most numerous and give the blood its color-bright red when oxygenated and darker red when low on oxygen.___ carry oxygen to the body’s tissues and remove carbon dioxide.
Red blood cells
Larger __ blood cells help to fight infection.
White
__, which help the blood to clot, are much smaller than either red or white blood cells.
Platelets
__is the fluid in which the cells float. It is a mixture of water, salts, nutrients, and proteins.
Plasma
A sticky, yellow fluid that carries the blood cells and nutrients and transports cellular waste material to the organs of excretion
Plasma
Cells that carry oxygen to the body tissues; also called erythrocytes
Red blood cells
__ is the force of circulating blood against the walls of the arteries
Blood pressure
__is the maximum pressure generated in the arms and legs during the contraction of the left ventricle, during the time period known as systole.
Systolic blood pressure
As the left ventricle relaxes in the stage known as diastole, the arterial pressure falls. When the left ventricle relaxes, the aortic valve closes and blood flow between the left ventricle and the aorta stops. The__ is the pressure exerted against the walls of the arteries while the left ventricle is at rest.
diastolic blood pressure
The__ measures the average blood pressure and is displayed when a noninvasive blood pressure is measured. The__ is a good measure of perfusion.
mean arterial pressure (MAP)
The average pressure in the circulatory system during one cardiac cycle
Mean arterial pressure MAP
the __ cycle consists of one systolic and one diastolic time period
The cardiac cycle
As the blood passes through an artery during systole, a__ is generated. This__ can be felt by placing a finger on the skin over the artery at a point where the artery lies near the skin surface and gently compressing.__ felt in the extremities, such as the radial and the posterior tibial, are called peripheral_, whereas__ near the trunk of the body, such as the femoral and carotid___, are known as central___.
pulse
Pulses that are closest to the core (central) part of the body where vital organs are located; include the carotid, femoral, and apical pulses
Central pulses
The rate of cardiac contractions can be increased or decreased by the_. The heart also has the
capability to increase or decrease the volume of blood it pumps with each contraction based on the____ response.
autonomic nervous system
To obtain an accurate measure of the efficiency of the heart, the volume of blood pumped and the heart rate are measured. This is determined by calculating the___. The____ is calculated by multiplying the heart rate by the volume of blood ejected with each contraction, or the stroke volume. This is the volume of blood that passes through the heart in 1 minute and is the best measure of the output of the heart. In the field, we have no way of directly measuring the volume of blood being pumped; therefore, we must rely on the heart rate and the strength of the pulse to estimate the cardiac output.
cardiac output
The constant flow of oxygenated blood to the tissues is known as_. Good___ requires three primary components. The first is a well-functioning heart, or pump. The heart must operate at an appropriate rate because a rate that is too slow or too fast will reduce the volume of blood circulated and, thus, reduce the cardiac output. When the heart beats too rapidly, there is not enough time between contractions for the heart to refill completely, and when the heart beats too slowly, the volume of blood circulated per minute decreases due to the slow pulse rate. The second component of good___ is an adequate volume of fluid, or blood. If there is blood loss through hemorrhage, the reduced volume will limit the amount of tissue that can be perfused. Third, the blood must be carried in a proper-size container. This means that the blood vessels must be appropriately constricted to match the volume of blood available so that circulation can occur without problems. If the blood vessels dilate, thereby increasing the size of the container, and the volume of fluid remains the same, there will not be enough blood to fill the blood vessels and__ will be reduced. If there is a problem with the functioning of the heart, the functioning of the blood vessels, or the volume of blood,___ will fall, which will lead to cellular death and, eventually, death of the patient.
perfusion
Cardiac output = ___ x __
Heart rate x stroke volume
The volume of blood pumped forward with each ventricular contraction
Stroke volume
The number of heartbeats during a specific time (usually 1 minute)
Heart rate
Chest pain or discomfort that is related to the heart usually stems from a condition called_, which is decreased blood flow, in this case, to the myocardium. A partial or complete blockage of blood flow through the coronary arteries can cause a portion of the myocardium to be deprived of enough oxygen and nutrients. The tissue soon begins to starve and, if blood flow is not restored, eventually dies. Ischemic heart disease, then, is disease involving a decrease in blood flow to one or more portions of the heart muscle.
ischemia
A lack of oxygen that deprives tissues of necessary nutrients, resulting from partial or complete blockage of blood flow; potentially reversible because permanent injury has not yet occurred
Ischemia
Most often, the low blood flow to heart tissue is caused by coronary artery_.___ is a disorder in which calcium and a fatty material called cholesterol build up and form a plaque inside the walls of blood vessels, obstructing flow and interfering with their ability to dilate or contract. Eventually, atherosclerosis can even cause complete occlusion, or blockage, of a coronary artery.____ usually involves other arteries of the body as well.
atherosclerosis
A blockage, usually of a tubular structure such as a blood vessel
Occlusion
The problem begins when the first trace of cholesterol is deposited on the inside of an artery. This may happen as early as the teenage years. As a person ages, more of this fatty material is deposited; the__, or the inside diameter of the artery, narrows. As the cholesterol deposits grow, calcium deposits can form as well. The inner wall of the artery, which is normally smooth and elastic, becomes rough and brittle with these atherosclerotic plaques. Damage to the coronary arteries may become so extensive that they cannot accommodate increased blood flow during times of maximum stress.
lumen
The inside diameter of an artery or other hollow structure
Lumen
For reasons that are still not completely understood, a brittle plaque will sometimes develop a crack, exposing the inside of the atherosclerotic wall. Acting like a torn blood vessel, the ragged edge of the crack activates the blood-clotting system, just as when an injury has caused bleeding. In this situation, however, the resulting blood clot will partially or completely block the lumen of the artery. If it does not occlude the artery at that location, the blood clot may break loose and begin floating in the blood, becoming what is known as a_____.
thromboembolism
A blood clot that has formed within a blood vessel and is floating within the bloodstream
Thromboembolism
thromboembolism is a blood clot that is floating through blood vessels until it reaches an area too narrow for it to pass, causing it to stop and block the blood flow at that point. Tissues downstream from the blood clot will experience a lack of oxygen (hypoxia). If blood flow is restored in a short time, the hypoxic tissues will recover. However, if too much time goes by before blood flow returns, the hypoxic tissues will die. If a blockage occurs in a coronary artery, the condition results in an__, a heart attack. Infarction means the death of tissue. The same sequence may also cause the death of cells in other organs, such as the brain. The death of heart muscle decreases the heart’s ability to pump and can also cause it to stop pumping completely (cardiac arrest).
acute myocardial infarction (AMI)
Death of a body tissue, usually caused by interruption of its blood supply
Infarction
In the united states, coronary artery disease is the number one cause of death for men and woman. The peak incidence of heart disease is between the ages of__, but can also strike teens and people in their 90s
45 and 64 years
A group of symptoms caused by myocardial ischemia; includes angina and myocardial infarction
Acute coronary syndrome
___is a term used to describe a group of symptoms caused by myocardial ischemia. As discussed earlier, myocardial ischemia is a decrease in blood flow to the heart, which leads to chest pain through reduced supply of oxygen and nutrients to the tissues of the heart. This can be a temporary situation known as angina pectoris, or a more serious condition, an AMI Because the signs and symptoms of these two conditions are very similar, they are treated the same under the designation of ACS. To understand them better, we will examine each one separately.
Acute coronary syndrome (ACS)
Chest pain does not always mean that a person is having an AMI. When, for a brief time, heart tissues are not getting enough oxygen, the pain is called__. Although___ can result from a spasm of an artery, it is most often a symptom of atherosclerotic coronary artery disease.___ occurs when the heart’s need for oxygen exceeds its supply, usually during periods of physical or emotional stress when the heart is working hard. A large meal or sudden fear may also trigger an attack. When the increased oxygen demand goes away (eg, the person stops exercising), the pain typically goes away.
angina pectoris, or angina
___is commonly described as crushing, squeezing, or “like somebody standing on my chest.” It is usually felt in the midportion of the chest, under the sternum. However, it can radiate to the jaw, the arms (frequently the left arm), the midportion of the back, or the epigastrium (the upper-middle region of the abdomen). The pain usually lasts from 3 to 8 minutes, rarely longer than 15 minutes. It may be associated with shortness of breath, nausea, or sweating. It usually disappears promptly with rest, supplemental oxygen, or nitroglycerin (NTG), all of which decrease the need for or increase the supply of oxygen to the heart. Although angina pectoris is frightening, it does not mean that heart cells are dying, nor does it usually lead to death or permanent heart damage. It is, however, a warning that you and the patient should take seriously. With angina, the electrical system can be compromised because the oxygen supply to the heart is diminished, and the person is at risk for problems with cardiac rhythm.
Anginal pain
Angina can be further differentiated into __ and __ angina
Stable and unstable angina
______angina is characterized by pain or discomfort in the chest of coronary origin that occurs in the absence of a significant increase in myocardial oxygen demand. if untreated, it is associated with a very high risk of spontaneous AMI.
Unstable angina
____angina is characterized by pain in the chest of coronary origin that occurs in response to exercise or some activity that increases the demand on the heart muscle beyond the heart’s capacity to increase its own blood flow. EMS often becomes involved when_____ becomes unstable, such as when a patient whose pain is normally relieved by sitting down and taking one nitroglycerin tablet has taken three tablets with no relief. Keep in mind that it can be difficult, even for physicians in hospitals, to distinguish between the pain of angina and the pain of an AMI. Patients experiencing chest pain or discomfort, therefore, should always be treated initially as if they are having an AMI.
Stable angina
The pain of an___ signals the actual death of cells in the area of the heart muscle where blood flow is obstructed. Once dead, the cells cannot be revived. Instead, they will eventually turn to scar tissue and become a burden to the beating heart, Therefore, fast action is critical in treating a heart attack. The sooner the arterial blockage can be cleared, the fewer the cells that may die. About 30 minutes after blood flow is cut off, some heart muscle cells begin to die. After about 2 hours, as many as one-half of the cells in the area can be dead; in most cases, after 4 to 6 hours, more than 90% will be dead. In many cases, however, opening the coronary artery with clot-busting (thrombolytic) medications or angioplasty (mechanical clearing of the artery) can prevent permanent damage to the heart muscle if done within the first few hours after the onset of symptoms. Therefore, immediate prehospital treatment and transport to the emergency department (ED) are essential
An AMl is more likely to occur in the larger, thick-walled left ventricle, which needs more blood and oxygen than the right
ventricle.
Acute myocardial infarction
A patient with an__ may show any of the following signs and symptoms:
• Sudden onset of weakness, nausea, and sweating without an obvious cause
• Chest pain, discomfort, or pressure that is often crushing or squeezing and that does not change with each breath
• Pain, discomfort, or pressure in the lower jaw, arms, back, abdomen, or neck
• Irregular heartbeat and syncope (fainting)
• Shortness of breath, or dyspnea
• Nausea/vomiting
• Pink, frothy sputum (indicating possible pulmonary edema)
• Sudden death
AMl
The pain of an__ differs from the pain of angina in three ways:
• It may or may not be caused by exertion but can occur at any time, sometimes when a person is sitting quietly or even sleeping.
• It does not resolve in a few minutes; rather, it can last between 30 minutes and several hours.
• It may or may not be relieved by rest or nitroglycerin.
AMI
__ is the number one killer in women in the united states, and EMTs should consider AMI even when the classic symptom of chest pain is not present. This is also true for older people and people with diabetes
Heart disease
The physical findings of__ vary, depending on the extent and severity of heart muscle damage. The following are common:
• General appearance. The patient often appears frightened. There may be nausea, vomiting, and a cold sweat. The skin is often pale or ashen gray because of poor cardiac output and the loss of perfusion, or blood flow through the tissue.
Occasionally, the skin will have a blue tint, called cyanosis; this is the result of poor oxygenation of the circulating blood
• Pulse. Generally, the pulse rate increases as a normal response to pain, stress, fear, or actual injury to the myocardium.
Because dyshythmias are common in an AMI, you may feel an irregularity or even a slowing of the pulse. The pulse may also be dependent on the area of the heart that has been affected by the AMI. Damage to the inferior area of the heart often presents with bradycardia.
• Blood pressure. Blood pressure may fall as a result of diminished cardiac output and diminished capability of the left ventricle to pump. However, most patients with an AMI will have a normal or possibly even elevated blood pressure.
• Respiration. The respiratory rate is usually normal unless the patient has CHF. In that case, respirations may become rapid and labored with a higher likelihood of cyanosis and possibly frothy sputum. A complaint of difficulty breathing is common with cardiac compromise, so even if the rate seems normal, look at the work of breathing, and treat the patient as if respiratory compromise were present.
• Mental status. Patients with AMls often experience confusion or agitation and sometimes experience an almost overwhelming feeling of impending doom. If a patient tells you, “I feel like I’m going to die,” pay attention.
AMl
An__ can have three serious consequences:
• Sudden death
• Cardiogenic shock
• Congestive heart failure
AMI
Sudden death is usually the result of cardiac arrest, in which the heart fails to generate effective blood flow. Although you cannot feel a pulse in someone experiencing cardiac arrest, the heart may still be twitching, though erratically. The heart is using up energy without pumping any blood. Such an abnormality of heart rhythm is a ventricular_, known as ventricular fibrillation (VF).
dysrhythmia
___. Rapid heart rhythm, usually at a rate of 150 to 200 beats/min. The electrical activity starts in the ventricle instead of the atrium. This rhythm usually does not allow adequate time between beats for the left ventricle to fill with blood. Therefore, the heart pumps less volume and the patient’s blood pressure may fall, or the pulse may be lost altogether. The patient may also feel weak or lightheaded or may even become unresponsive. In some cases, existing chest pain may worsen or chest pain that was not there before onset of the dysrhythmia may develop. Most cases of ventricular tachycardia (VT) will be sustained but may deteriorate into VF.
Ventricular tachycardia
. Disorganized, ineffective quivering of the ventricles. No blood is pumped through the body, and the patient becomes unconscious within seconds. The only way to convert this dyshythmia is to defibrillate the heart. To defibrillate means to shock the heart with a specialized electric current in an attempt to stop the chaotic, disorganized contraction of the myocardial cells and allow them to start again in a synchronized manner to restore a normal rhythmic beat. Defibrillation is most likely to be successful in terms of saving a life if delivered within the first few minutes of sudden death. If a defibrillator is not immediately available, CPR must be initiated until the defibrillator arrives. Even if CPR is begun at the time of collapse, chances of survival diminish approximately 7% to 10% each minute until defibrillation is accomplished.
If uncorrected, unstable VT or VF will eventually lead to asystole, the absence of all heart electrical activity. Without CPR, asystole may occur within minutes. Asystole usually reflects a long period of ischemia, and nearly all patients you find in asystole will die.
Ventricular fibrillation
The complete absence of all heart electrical activity
Asystole
Shock is present when body tissues do not get enough oxygen, causing body organs to malfunction. In__, often caused by a heart attack, the problem is that the heart lacks enough power to force the proper volume of blood through the circulatory system.___ is more commonly found after an AMI that affects the inferior and posterior regions of the left ventricle of the heart because this ventricle provides circulation to the majority of the body.
__can develop immediately or sometime after an AMI. The various signs and symptoms of___ are produced by the improper functioning of the body’s organs. The challenge for you is to recognize shock in its early stages, when treatment is much more likely to be successful.
cardiogenic shock
A state in which not enough oxygen is delivered to the tissues of the body, caused by low output of blood from the heart. It can be a severe complication of a large acute myocardial infarction, as well as other conditions.
Cardiogenic shock
Failure of the heart occurs when the ventricular myocardium is so profoundly damaged that it can no longer keep up with the return flow of blood from the atria.___ can occur at any time after a myocardial infarction, in the setting of heart valve damage, or as a consequence of long-standing high blood pressure. Any condition that weakens the pumping strength of the heart may cause__, and this often happens after a heart attack.
Congestive heart failure (CHF)
Just as the pumping function of the left ventricle can be damaged by coronary artery disease, it can also be damaged by diseased heart valves or chronic hypertension. In any of these cases, when the muscle can no longer contract effectively, the heart tries other ways to maintain an adequate__. Two specific changes in heart function occur: The heart rate increases, and the left ventricle enlarges to increase the amount of blood pumped each minute.
When these adaptations can no longer make up for the decreased heart function, CHF eventually develops.
cardiac output
With left-sided heart failure, the lungs become congested with fluid because the left side of the heart fails to pump the blood effectively. Blood tends to back up in the pulmonary veins, increasing the pressure in the capillaries of the lungs. When the pressure in the capillaries exceeds a certain level, fluid (mostly water) passes through the walls of the capillary vessels and into the alveoli. This condition is called__. It may occur suddenly, as in an AMI, or slowly over months, as in chronic CHF. Sometimes, in patients with an acute onset of CHF, severe pulmonary edema will develop, in which the patient has pink, frothy sputum and severe dyspnea.
pulmonary edema
With____ heart failure, blood backs up in the venae cavae, resulting in edema in the lower extremities or distention of the veins in the neck.
right-sided heart failure
The precontraction pressure in the heart as the volume of blood builds up
Preload
If the right side of the heart is damaged, fluid collects in the body, often showing up as swelling in the feet and legs. The
collection of fluid in the part of the body that is closest to the ground is called__
dependent edema.
Because the right side of the heart supplies the__ for the left side of the heart, right heart failure can result in an inadequate supply of blood to the left ventricle, resulting in a drop in the systemic blood pressure. It is important to realize that some patients may present with signs of both left- and right-side heart failure because left-side failure often leads to right-side failure.
preload
___ is defined as any systolic blood pressure greater than 130 mm hg or a diastolic blood pressure greater than 80 mm hg
Hypertension
A __ emergency is defined as a systolic pressure greater than 180 mm hg in the presence of impending or progressive organ damage
Hypertensive emergency
An __ is a weakness in the wall of the aorta. The aorta dilates at the weakened area, which makes it susceptible to rupture
Aortic aneurysm
A___ occurs when the inner layers of the aorta become separated, allowing blood (at high pressures) to flow between the layers. Uncontrolled hypertension is the primary cause of__
dissecting aneurysm
__Versus__
Aneurysm
Onset of pain - Gradual, with additional symptoms
Quality of pain - Tightness or pressure
Severity of pain - Increases with time
Timing of pain - May wax and wane
Region/radiation - Substernal; back is rarely involved
Clinical signs - Peripheral pulses equal
Dissecting Aneurysm
Onset of pain - Abrupt, without additional symptoms
Quality of pain - Sharp or tearing
Severity of pain - Maximal from onset
Timing of pain - Does not abate once it has started
Region/radiation - Back possibly involved, between the shoulder blades
Clinical signs - Blood pressure discrepancy between arms or decrease in a femoral or carotid pulse
AMI Versus Dissecting Aortic
__prevents new clots from forming or existing clots from getting bigger. Administer low-dose aspirin according to local protocol. Low-dose aspirin comes in 81-mg chewable tablets. The recommended dose is 162 mg (two tablets) to 324 mg (four tablets). Be sure you have verified that the patient is not allergic to aspirin before you give it. Also, ask the patient if he or she has any history of internal bleeding such as stomach ulcers, and, if so, contact medical control before giving the patient__.
Aspirin (acetylsalicylic acid)
___relaxes the muscle of blood vessel walls, dilates coronary. arteries, increases blood flow and the supply of oxygen to the heart muscle, and decreases the workload of the heart.
___also dilates blood vessels in other parts of the body and can cause a decrease in blood pressure and a severe headache. Other side effects include changes in the patient’s pulse rate, including tachycardia or bradycardia.
Therefore, you should obtain the patient’s blood pressure within 5 minutes after each dose. If the systolic blood pressure is less than 100 mm Hg, do not give nitroglycerin. Other contraindications include the presence of a head injury, use of erectile dysfunction drugs within the previous 24 to 48 hours, and the maximum prescribed dose of nitroglycerin has already been given (usually three doses). Drugs used for erectile dysfunction include sildenafil (Viagra), tadalafil (Cialis), avanafil (Stendra), and vardenafil (Levitra, Staxyn).
Nitroglycerin
After you obtain permission from medical control, administer the___ if required.___ works in most patients within 5 minutes. Most patients who have been prescribed___ carry a supply with them.
Nitrostat is one trade name for__. Patients are instructed to take one dose of___ under the tongue whenever they have an episode of angina that does not immediately go away with rest. If the pain is still present after 5 minutes, patients are typically instructed by their physicians to take a second dose. If the second dose does not work, most patients are told to take a third dose and then call for EMS. If the patient has not taken all three doses, you can administer the medication, if you are allowed to do so by local protocol.
Be aware that____ will lose its potency over time, especially if exposed to light and/or heat. Patients who take it only rarely may keep a bottle in their pocket for months. It may lose its potency even before its expiration date.
When the___ tablet loses its potency, patients may not feel the fizzing sensation when the tablet is placed under their tongue, and they may not experience the normal burning sensation and headache that often accompany___ administration. Note that the fizzing only occurs with a potent tablet, not with the spray form. To safely assist the patient with nitroglycerin, follow the steps listed in
nitroglycerin
Some EMS systems will allow EMTs to place electrodes, attach the leads, and obtain and transmit an electrocardiogram (ECG) tracing prior to transport. If your service allows you to perform this skill, the following information will guide you.
The goal is to obtain the ECG within less than__ of your first contact with the patient. Be sure to familiarize yourself with the operation of the monitor that your service uses, including how to obtain and transmit ECG tracings before using it on a call.
10 minutes
Electrodes used in the prehospital setting are generally adhesive and have a gel center to aid in skin contact.
Whichever type is used, certain basic principles should be followed to achieve the best skin contact and minimize__ in the signal.___ refers to an ECG tracing with waves that are the result of interference, such as patient movement, rather than the heart’s electrical activity.
artifact
A tracing on a ECG that is the result of interference, such as patient movement, rather than the hearts electrical activity
Artifact
After obtaining an ECG tracing, it is important to make sure you have a high-quality printout. You should be able to see the QRS complexes (the largest, usually narrow, deflections on the ECG) clearly without interference from artifact. Each QRS complex represents one contraction of the___, so the closer together they are, the faster the heartbeat.
ventricles
If two QRS complexes are less than 15 mm apart (three large boxes), the heart rate is over__ and the rhythm is a tachycardia.
100
If the QRS complexes are more than 25mm apart (five large boxes), the rate is less than__ beats per minute and the rhythm is a bradycardia. Rhythms such as tachycardia and bradycardia may cause a patient to have altered mental status or a low blood pressure.
60
You may also see a small rounded wave before the QRS called a __, which represents the contraction of the atria
P wave
After each QRS complex, you should see a __ that represents the repolarization (or recharging) of the ventricles
T wave
In a___, a blood vessel from the chest or leg is sewn directly from the aorta to a coronary artery beyond the point of the obstruction.
coronary artery bypass graft
Another procedure is_____, which aims to dilate, rather than bypass, the coronary artery. In this procedure, which is usually called angioplasty or balloon angioplasty, a tiny balloon is attached to the end of a long, thin tube. The tube is introduced through the skin into a large artery, usually in the groin or wrist, and then threaded under x-ray control into the narrowed coronary artery. Once the balloon is in position inside the coronary artery, it is inflated. The balloon is then deflated, and the tube is removed from the body. Sometimes, a metal mesh cylinder called a stent is placed inside the artery instead of or after the balloon. The stent is left in place permanently to help keep the artery from narrowing again.
A patient who has had an AMl or angina in the past will possibly have had one of these procedures.
percutaneous transluminal coronary angioplasty
In the United States, many people with heart disease have cardiac____ to maintain a regular cardiac rhythm and rate.____ are inserted when the electrical control system of the heart no longer functions properly. These battery-powered devices deliver an electrical impulse through wires that are in direct contact with the myocardium. The generating unit is generally placed under a heavy muscle or a fold of skin. It typically resembles a small silver dollar under the skin in the left upper portion of the chest
pacemakers
More and more patients who survive cardiac arrest due to VF have a small _____implanted (FIGURE 17-13). Some patients who are at particularly high risk for a cardiac arrest have them as well. These devices are attached directly to the heart and can prolong the lives of certain patients. They continuously monitor the heart rhythm, delivering shocks as needed. Regardless of whether a patient having an AMI has an automatic implantable cardiac defibrillator, he or she should be treated like all other patients having an AMI. Treatment should include performing CPR and using an AED if the patient goes into cardiac arrest. Generally, the electricity from an automatic implantable cardiac defibrillator is so low that it will not have an effect on rescuers and, therefore, should not be of concern to you.
automatic implantable cardiac defibrillator
A temporary alternative to the implantable cardiac defibrillator is the____. This device is a vest with built-in monitoring electrodes and defibrillation pads, which is worn by the patient under his or her clothing. The vest is attached to a monitor worn on a belt or hung from a shoulder strap. The monitor provides alerts and voice prompts when it recognizes a dangerous rhythm and before a shock is delivered. It takes 25 to 60 seconds from detection of the rhythm problem to delivery of the shock. Unlike the implantable defibrillator, this device uses high-energy shocks similar to an AED, so you should avoid contact with the patient if the device warns that it is about to deliver a shock. An audible warning alerting rescuers to stay clear will state, “Bystanders, do not interfere,” before the shock is delivered. Blue gel under the large defibrillation pads indicates that the device has already delivered at least one shock.
If the patient is in cardiac arrest, the vest should remain in place while CPR is being performed unless it interferes with compressions. If it is necessary to remove the vest, simply remove the battery from the monitor and then remove the vest.
You can then use your own AED on the patient. Any patient who is wearing a device that has already delivered a shock should be transported to the hospital for further evaluation.
external defibrillator vest
____are used to enhance the pumping function of the left ventricle in patients with severe heart failure or in patients who need a temporary boost due to a myocardial infarction. There are several types of__; the most common ones have an internal pump unit and an external battery pack. These pumps are almost all continuous, so most of these patients will not have any palpable pulses. If you encounter a patient with an__, he or she (or his or her family members) may be able to tell you about the unit. Unless it malfunctions, you should not need to deal with it. If you are unsure of what to do, contact medical control for assistance. Also,___ provide a number to call for assistance. Transport all___ supplies and battery packs to the hospital with the patient.
Left ventricular assist devices (LVADs)
AEDs deliver electrical energy from one pad to the other (and then back to the first pad) to electrically stun the heart and allow it to resume normal function. The amount of electricity delivered by the machine varies among the manufacturers, but each one has shown that the energy delivered is adequate to defibrillate the heart. The factors involved in the defibrillation include voltage, current, and__. Most AEDs are set up to adjust the voltage based on the___ (or resistance of the body to the flow of electricity) to deliver the proper amount of current, which is what causes the cells to defibrillate.
impedance
In the late 1970s and early 1980s, scientists developed a small computer that could analyze electrical signals from the heart and determine when VF was taking place. This development, along with improved battery technology, made the__—a device that can automatically administer an electrical shock to the heart when needed-possible.
automated portable defibrillator
___has several advantages. First, the machine is fast, and it delivers the most importani treatment for a patient in VF: an electrical shock. It can be delivered within 1 minute of your arrival at the patient’s side.
Second,___ are easy to operate. ALS providers do not have to be on the scene to provide this definitive care.
Current___ offer two other advantages. The shock can be given through remote, adhesive defibrillator pads, which are
safe to use. Also, the pad area is larger than manual paddles, which means that the transmission of electricity is more efficient. Usually, there are pictures on the pads to remind you where they go on the patient’s chest. As a safety measure, make sure the patient is not lying on wet ground or touching metal objects when he or she is being shocked
Automated external defibrillation
Not all patients in cardiac arrest require an electrical shock. Although the cardiac rhythm of all patients in cardiac arrest should be analyzed with an AED, some do not have shockable rhythms (eg, pulseless electrical activity and asystole).
______(flatline) indicates that no electrical activity remains and therefore defibrillation will not help. Pulseless electrical activity refers to a state of cardiac arrest that exists despite an organized electrical complex; defibrillation could possibly make this situation worse. In both cases, CPR should be initiated as soon as possible, beginning with chest compressions.
Asystole
Six links of of the chain of survival
• Recognition of early warning signs and immediate activation of EMS
• Immediate CPR with emphasis on high-quality chest compressions
• Rapid defibrillation
• Basic and advanced EMS
• ALS and postarrest care
• Recovery
CPR helps patients in cardiac arrest because it prolongs the period during which defibrillation can be effective. Rapid defibrillation has successfully resuscitated many patients with cardiac arrest due to VF. However, defibrillation works best if it takes place within ___of the onset of the cardiac arrest.
2 minutes
The fifth link in the chain of survival is____. This refers to continuing ventilation at 10 breaths/min; maintaining oxygen saturation between 94% and 99%; ensuring systolic blood pressure is above 90 mm Hg; and using targeted temperature management when the patient arrives at the hospital. It also includes cardiopulmonary and neurologic support at the hospital as well as other advanced assessment techniques and interventions when indicated. The final step in the chain of survival, recovery can take a year or longer for many of the 10% of victims of out-of-hospital cardiac arrest who are fortunate enough to survive.
ALS and post-cardiac arrest care
An error can also occur when the__ is applied to a responsive patient with a rapid heart rate. Most__ identify a regular rhythm faster than 150 or 180 beats/min as VT, which should be shocked if the patient is pulseless. However, shocking VT in a patient with a pulse may result in the patient losing his or her pulse and going into cardiac arrest. To avoid this problem, you should apply the___ only to unresponsive pulseless patients.
AED
The return of a pulse and effective blood flow to the body in a patient who previously was in cardiac arrest
The return of spontaneous circulation
