Cardiology

Which of the following statements regarding the AED is correct?

AEDs can safely be used in infants and children less than 8 years of age.

Which of the following clinical signs should alert the EMT that a patient has left heart failure?

Dyspnea on exertion Signs of left heart failure are reflective of blood that backs up in the lungs and causes pulmonary edema. These include exertional dyspnea, paroxysmal nocturnal dyspnea, dyspnea while lying down (orthopnea), and coughing up blood (hemoptysis). Signs of right heart failure are reflective of blood that backs up in the systemic circulation. These include peripheral edema, jugular venous distention, and abdominal distention. An irregular pulse indicates the presence of a cardiac dysrhythmia, which could be present with left or right heart failure.

Which of the following clinical presentations is MOST consistent with right heart failure?

Peripheral edema and jugular venous distention

At the end of ventricular relaxation, the left ventricle contains 110 mL of blood. This is referred to as the:

Preload Preload is the amount of pressure on the ventricular wall at the end of ventricular relaxation (diastole), and is influenced by the volume of blood in the ventricle just before it contracts. Afterload refers to the resistance that the ventricles must contract against.

When treating a patient with chest pain, pressure, or discomfort, you should FIRST:

place the patient in a position of comfort. An important aspect of treating a patient with chest pain, pressure, or discomfort is to ensure that the patient is in a comfortable position. Most of the time, the patient will already be in this position upon your arrival. A comfortable position will help minimize anxiety, which in turn decreases cardiac oxygen consumption and demand.

In most people, the inferior aspect of the left ventricle receives its blood supply from the:

right coronary artery The right coronary artery (RCA) supplies blood to the entire right side of the heart; in most people, it also supplies blood to the inferior aspect of the left ventricle in most people.

Common signs and symptoms of a hypertensive emergency include:

ringing in the ears, headache, and epistaxis

A middle-aged woman took three of her prescribed nitroglycerin tablets after she began experiencing chest pain. She complains of a bad headache and is still experiencing chest pain. You should assume that:

she has ongoing cardiac ischemia

The maximum pressure generated in the arms and legs during contraction of the left ventricle is called:

systolic blood pressure

When the vital organs of an 85-year-old patient need additional blood flow, the heart may not be able to meet the increased need because:

the reserve capacity of the heart is reduced as a person ages. As the heart's muscle mass and tone decrease, the amount of blood pumped out of the heart per beat (stroke volume) is reduced. The residual (reserve) capacity of the heart is also reduced; therefore, when the vital organs of the body need additional blood flow, the heart is less able to meet that need as effectively as a younger person's heart.

Ischemic heart disease is a condition in which:

there is a decrease in blood flow to one or more portions of the heart muscle.

A 45-year-old woman calls EMS because of severe chest pain. When you arrive, she advises you that she has taken two of her husband's nitroglycerin tablets without relief. Her BP is 110/60 mm Hg, her pulse is 100 beats/min, her respirations are 16 breaths/min, and her oxygen saturation is 95%. You should:

transport the patient without delay and monitor her blood pressure en route.

A 60-year-old woman presents with chest discomfort, confusion, and weakness. The patient's husband tells you that she vomited once before EMS arrival. The patient's BP is 70/40 mm Hg, her pulse is 45 beats/min and weak, and her respirations are 14 breaths/min and unlabored. Which of the following is the MOST likely cause of her hypotension?

Bradycardia When the heart rate is too slow or too fast, cardiac output can fall, resulting in hypotension.

Which of the following statements regarding ventricular fibrillation (V-Fib) is correct?

In V-Fib, the heart is not pumping any blood and the patient is pulseless. Ventricular fibrillation (V-Fib) is a disorganized, ineffective quivering of the heart muscle. No blood is pumped through the body and the patient is pulseless. Loss of consciousness occurs within seconds following the onset of V-Fib.

Which of the following structures is the primary pacemaker, which sets the normal rate for the heart?

Sinoatrial node Cardiac pacemakers are bundles of nerves that generate electrical impulses and conduct them to the cardiac cells, resulting in contraction of the myocardium (heart muscle). In a normal healthy heart, the sinoatrial (SA) node is the primary pacemaker that sets the inherent rate for the heart. The SA node generates electricity at a rate of 60 to 100 electrical discharges per minute; hence the normal adult heart rate is 60 to 100 beats/min. The atrioventricuar (AV) node serves as the heart's secondary pacemaker; if the SA node fails, the AV node resumes the pacing function of the heart, although at a slower rate (40 to 60 beats/min). The bundle of His and Purkinjie fibers, located within the ventricles, may serve as tertiary pacemakers if the SA and AV nodes fail; their inherent pacing rate is 20 to 40 beats/min.

A 62-year-old male with a history of coronary artery disease began experiencing chest pain and nausea while on his daily jog. After sitting down and resting for 5 minutes, his pain and nausea resolve. Which of the following BEST describes this patient's condition?

Stable angina pectoris Angina is classified as being "stable" or "unstable." Stable angina is characterized by cardiac-related chest pain that resolves with rest and/or nitroglycerin. Unstable angina is characterized by cardiac-related chest pain that occurs in response to progressively less physical exertion (for example, during rest).

A 50-year-old man presents with crushing chest pain that suddently began about 30 minutes ago. He is diaphoretic and anxious. The EMT should:

administer chewable aspirin

A 65-year-old man has generalized weakness and chest pressure. He has a bottle of prescribed nitroglycerin, but states that he has not taken any of his medication. The EMT should:

administer up to 325 mg of aspirin if the patient is not allergic to it. Aspirin has clearly been shown to reduce mortality and morbitiy associated with acute coronary syndrome (ACS) and should be given as early as possible; the dose is 160 to 325 mg. Even though this patient has chest pain and prescribed nitroglycerin, you must first complete a secondary assessment and obtain baseline vital signs. Medical control will need this information—specifically, the patient's blood pressure—to determine whether you should assist the patient with his nitroglycerin.

An 88-year-old female experienced a syncopal episode. She is now conscious, but complains of dizziness and generalized weakness, and her pulse is 170 beats/min and irregular. The EMT should recognize that this patient's syncope was MOST likely caused by:

an acute cardiac dysrhythmia. Because her heart is beating so fast, you should suspect that her syncope occurred because of a drop in her blood pressure secondary to reduced ventricular filling time; the faster the heart beats, the less time there is for the ventricles to fill in between contractions. A fast, irregular pulse indicates the presence of a cardiac dysrhythmia.

The coronary arteries fill with blood when the:

aortic valve closes During systole (cardiac contraction), the aortic valve opens and covers the openings to the coronary arteries. During diastole (cardiac relaxation), the aortic valve closes; this causes blood to flow back down the aorta and fill the coronary arteries. Therefore, coronary perfusion occurs when the heart relaxes.

You are treating a 60-year-old man in cardiac arrest. After delivering a shock with the AED and performing CPR for 2 minutes, you achieve return of spontaneous circulation. Your next action should be to:

assess his airway and ventilatory status.

After defibrillating a man in cardiac arrest, you resume CPR. As you are about to reanalyze his cardiac rhythm 2 minutes later, your partner tells you she can definitely feel a strong carotid pulse. You should:

assess the patient's breathing effort.

In patients with heart disease, acute coronary syndrome is MOST often the result of:

atherosclerosis Atherosclerosis 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 blood flow.

When an electrical impulse reaches the atrioventricular node, it is briefly delayed so that:

ventricular filling can occur The heart functions as a double pump; when the atria are contracting, the ventricles are filling, and when the ventricles are contracting, the atria are filling. In order to maintain the double pump effect, the electrical impulse coming from the sinoatrial node must undergo a brief delay at the atrioventricular node; this delay allows the ventricles to fill with blood. Most of the blood that fills the ventricles does so passively, with final filling occurring during atrial contraction; this is called the atrial kick. The brief delay at the AV node does not affect when the aortic valve opens, when the ventricles contract, or when the atria relax.

A patient whose artificial pacemaker has failed would MOST likely experience:

weakness and bradycardia If a pacemaker stops working, as when the battery wears out or an internal lead becomes detached, the patient often experiences syncope, dizziness, or weakness because of a slow heart rate (bradycardia).