Chapter 14: Cardiovascular Emergencies

Question 1

Discuss

Heart’s electrical system

Answer 1

Impulses from begin in sinus node (sinoatrial node) in superior right atrium, trvael across atria causing contraction, cross AV node where signal is delayed 0.1-0.2 s, then to ventricles via Purkinje fibers

Question 2

Discuss

Automaticity

Answer 2

In heart muscle, muscle can contract without nerve stimulus

Question 3

Discuss

Two parts of autonomic nervous system

Answer 3

Sympathetic: fight or flight, physical activity. Parasympathetic: Opposite of sympathetic

Question 4

Discuss

Anatomy of coronary arteries

Answer 4

Come from aorta just superior to aortic valve. Left and right. Left splits into circumflex branch which branches posteriorly to descending coronary artery in posterior interventricular groove. Right supplies right ventricle and usually the inferior wall of left ventricle.

Question 5

Discuss

Anatomy of descending aorta

Answer 5

Branches at umbilicus to the iliac arteries. They become the femoral arteries. At knee, becomes popliteal then brances to anterior and posterior tibial arteries and posterior branches to peroneal

Question 6

Discuss

Anatomy of ascending aorta

Answer 6

Branches into subclavian and carotid arteries

Question 7

Discuss

Cardiac output

Answer 7

Volume of blood pumped in 1 min

Question 8

Discuss

Atherosclerosis

Answer 8

Calcium and cholesterol buildup form plaque. Forms partial occlusion. Can crack and cause clotting, completely occluding vessel.

Question 9

Discuss

Thromboembolism

Answer 9

Blood clot embolism

Question 10

Discuss

Acute myocardial infarction

Answer 10

AMI. Blockage occuring in coronary artery leads to death of heart tissue (infarction). Pain comes from cell death. 30 minutes after flow cut off, cells begin to die.

Question 11

Discuss

Acute coronary syndrome

Answer 11

A group of symptoms caused by myocardial ischemia.

Question 12

Discuss

Angina pectoris

Answer 12

Myocardial ischemia for a short time (Typically 3-8 min, rarely longer than 15). When heart’s needs exceed supply, often during exertion or emotional stress. Described as crushing, typically under sternum but can radiate to left arm, jaw, mid back, epigastrium.

Question 13

Discuss

Stable vs. unstable angina pectoris

Answer 13

Unstable: progressively less exertion required to stimulate angina (untreated can lead to AMI). Stable: relieved by things that normally relieve it.

Question 14

Discuss

What should EMT always treat chest pain as?

Answer 14

Potential AMI

Question 15

Discuss

AMI vs. acute angina pectoris difference

Answer 15

1. AMI can occur at any time rather than just exertion.
2. AMI does not resolve in a few minutes.
3. May or may not be relieved by nitro

Question 16

Discuss

What pt groups can often have AMI without chest pain?

Answer 16

Females and diabetics

Question 17

Discuss

Consequences of AMI

Answer 17

Sudden death, cardiogenic shock, CHF

Question 18

Discuss

Arrythmias

Answer 18

Tachycardia, bradycardia, ventricular tachycardia (150-200 bpm, impulse starts in ventricles not SA node, insufficient time to refill with blood), ventricular fibrillation (quivering), asystole (absence of electrical activity)

Question 19

Discuss

CHF

Answer 19

Usually between first few hours and days after AMI, also from diseased heartvalves and chronic hypertension. Causes pulmonary edema, quickly as in AMI or over time as in chronic CHF. Right sided CHF causes dependent edema.

Question 20

Discuss

Hypertensive emergency

Answer 20

Systolic > 160 or rapid rise in systolic (Normal hypertension is systolic>140 or diastolic>90). S/S: sudden, severe headache. Can lead to stroke or dissecting aortic aneurysm.

Question 21

Discuss

Dissecting aortic aneurysm

Answer 21

Aorta likely to rupture from delamination of wall. S/S sudden onset of sharp stabbing pain, not crushing.

Question 22

Discuss

AED

Answer 22

Automated external defibrillator. Biphasic shock defibs more efficiently and with lower energy than monophasic (120 J vs. 360 J).

Question 23

Discuss

Protocol for attaching AED when cardiac arrest witnessed vs. not

Answer 23

Witnessed: Apply AED immediately. If not (>5 min to scene), perform 5 cycles of CPR.

Question 24

Discuss

Nitroglycerin

Answer 24

Vasodilator. Max of three doses usually. Contraindicated by BP<100 or ED meds in last 24 hours.

Question 25

Discuss

Cardiogenic shock

Answer 25

When heart lacks enough power to acheive adequate cardiac output. More commonly found in AMI that affects inferior and posterior regions of left ventricle.

Question 26

Discuss

Preferred position of transport for CHF pt’s

Answer 26

Sitting with legs down to avoid pooling of fluids in torso.

Question 27

Discuss

4 links in chain of survival for cardiac arrest

Answer 27

Recognition of early warning signs and activation of EMS, immediate bystander CPR, early defibrillation, early ALS

Question 28

Discuss

Bradycardia

Answer 28

<60 bpm

Question 29

Discuss

Cardiac arrest

Answer 29

Heart fails to generate effective/detectable blood flow. Pulses not palpable, even if muscular or electrical activity continues in heart

Question 30

Discuss

Tachycardia

Answer 30

>100bpm

Question 31

S/S

AMI

Answer 31

• sudden onset weakness, nausea, etc;
• chest pain or crushing feeling that doesn’t change with breath
• radiated pain
• irregular heartbeat
• syncope
• dyspnea
• pink sputum

Question 32

Discuss

Timeframe of angina pectoris?

Answer 32

3-8 min. Rarely longer than 15 min.