Chapter 17 cardiovascular emergencies

blood flow through the heart

right side vs left side of heart

pulmonary circulation artery & vein

pulmonary artery: deoxygenated blood

pulmonary vein: oxygenagted blood

heart’s electrical system

controls heart rate & coordinates atria & ventricles

automaticity

allows spontaneous contraction w/o stimulus from nerve source

if impulses come from SA node: other myocardial cells will contract

if no impulse arrives: other cells capable of creating own impulses & stimulating a contraction

autonomic nervous system

involuntary activities

2 parts: sympathetic (fight or flight) or parasympathetic

stroke volume

amount of blood ejected from each contraction

coronary arteries

blood vessels that supply blood to heart muscle, occlusion of one of these is AMI

four components of blood

red blood cells (carry hemoglobin)

white blood cells

platelets

plasma: fluid cells float in

blood pressure

force of circulating blood against artery walls

systolic: max pressure generated by left ventricle

diastolic: pressure against artery walls while left ventricle @ rest

peripheral vs central pulses

peripheral: felt in extremities

central: felt near body’s trunk

ischemia

decreased blood flow

ischemic heart disease

decreased blood flow to 1 or more portions of the heart

atherosclerosis

buildup of calcium & cholesterol in the arteries, can cause occlusion of the arteries, fatty material accumulates w/ age

thromboembolism

blood clot floating through blood vessels, if clot lodges in coronary artery AMI occurs

acute coronary syndrome (ACS) caused by?

myocardial ischemia

angina pectoris

oxygen demand exceeds supply

crushing squeezing pain, doesn’t usually result in serious damage, in field: can’t differentiate between angina & AMI

unstable vs stable angina

unstable: may not be relieved

stable: relieved by rest or nitroglycerin

AMI & treatment

acute myocardial infarction

actual death of cells in heart muscle

treatment: clot busting (thrombolytic) drugs or angioplasty w/in first few hrs prevent damage

signs & symptoms of AMI

not always due to exertion, lasts 30 min-several hrs, not always relieved by rest or nitroglycerin, arm/back pain

3 serious consequences of AMI

sudden death, cardiogenic shock, congestive heart failure

dysrhythmia

heart rhythm abnormalities

premature ventricular contractions, tachycardia, bradycardia, ventricular tachycardia

asystole

absence of all heart electrical activity, reflects long periods of ischemia

cardiogenic shock

heart lacks power to force enough blood through circulatory system, inadequate O2 to body tissues causes organ malfunction

CHF

congestive heart failure

increased heart rate & enlargement of left ventricle no longer make up for decreased heart function

left side failure: lungs become congested with fluid

right side failure: dependent edema, fluid in lower extremities

hypertensive emergencies signs/symptoms

systolic > 180 mmHg, sign/symptoms: sudden severe headache common, AMS, pulmonary edema, vision changes

aortic aneurysm

weakness in wall of aorta, susceptible to rupture, primary cause: uncontrolled hypertension

dissecting anuerysm

inner layers of aorta become separated, blood flows into those layers

care for chest pain & discomfort

position of comfort, give O2 if needed, possibly administer low dose aspirin & assist w/ prescribed nitroglycerin

electrode placement of white, black, green, red

white: right shoulder

black: left shoulder

green: right lower abdomen

red: left lower abdomen

coronary artery graft

chest or leg blood vessel is sewn from aorta to a coronary artery beyond point of obstruction

percutaneous transluminal coronary angioplasty

tiny balloon inflated inside narrowed coronary artery

cardiac pacemakers

left upper chest, maintain regular cardiac rhythm & rate, deliver electrical impulse through wires in direct contact w/ myocardium

automatic implantable cardiac defibrillators

used by some patients who have survived cardiac arrest due to ventricular fibrillation, monitor heart rhythm & shock

left ventricular assist devices (LVADs)

enhance pumping of left ventricle, possible patient doesn’t have a pulse w/ these devices

cardiac arrest

complete cessation of cardiac activity, absence of carotid pulse, start CPR & get AED

automated external defibrillation

analyzes electrical signals from heart, identifies ventricular fibrillation, administers shock to heart when needed

AED considerations

not all cardiac arrest patients require shock, pulseless electrical activity usually refers to a state of cardiac arrest

integrating AED & CPR

don’t touch patient during analysis & defibrillation, CPR shouldn’t be stopped more than 10 s

ROSC

return of spontaneous circulation

monitor for respirations, provide O2 via BVM at 10-12 breaths/min, maintain SPO2 95-99%, assess BP