NURS 20025: Exam 2

Stroke Volume (SV)

The volume of blood pumped forward with each ventricular contraction.

Preload

the amount of blood left in the left ventricle (at the end of diastole)

Afterload

resistance to left ventricular ejection

Contractility

ability of heart muscle to contract

Cardiac output

amt of blood pumped by the heart each minute

CO equation

HR x SV = CO

Cardiac conduction pathway

SA node, AV node, bundle of His, right and left bundle branches, Purkinje fibers

coronary circulation

receive blood during diastole; the right and left arteries branch off the base of the aorta

Pulse pressure

difference between systolic and diastolic pressure

pulse pressure represents what?

filling pressure of coronary arteries

electrocardiography

process of recording the electrical activity of the heart

P wave

atrial depolarization

PR wave

tracks the atrial impulse through the AV node, bundle of HIS, and bundle branches

QRS complex

ventricular depolarization

ST segement

end of ventricular conduction/depolarization; beginning of ventricular repolarization

T wave

ventricular repolarization

What are three physiological features that effect blood pressure?

vasomotor center; hormones; emotions

vasomotor center

regulates blood pressure and flow by dilating and constricting blood vessels

Baroreceptors

Cells that are sensitive to blood pressure changes.

Chemoreceptors

respond to pH; oxygen; carbon dioxide

Name some emotions that affect BP

Anger; depression; stress; lethargy

Name hormones that affect BP

ADH; RAAS

ADH

antidiuretic hormone

RAAS

renin-angiotensin-aldosterone system

Fluid loss that leads to a decrease in blood volume

dehydration

Hormones involved in fluid retention

ADH; Aldosterone

Peripheral resistance responds to which nervous system?

Sympathetic

Increase in blood viscosity effects _______.

peripheral resistance which affects blood pressure

Renin and Angiotensin II effects

peripheral resistance which affects blood pressure

Blood pressure is affected by cardiac output: T or F?

True. Along with peripheral resistance and blood viscosity.

autoregulation of blood flow

ability of organ to regulate own blood flow

Histamine

When released, blood vessels dilate and blood pressure decreases.

Bradykinin

potent vasodilator; peptide

prostaglandins include both vasodilators and vasoconstrictors: T or F

True

response to hypertension

Renal secretion increases (increase in urine output) which leads to fluid loss and lowers BP

response to hypotension

Adrenal Medulla secretes epinephrine and norepinephrine. Angiotensin II and Aldosterone are formed. Kidneys retain fluid, and BP increases.

Prehypertension

120-139/80-89

Hypertension

140/90 or higher

primary hypertension

denotes high blood pressure from an unidentified cause; also called essential hypertension; 90-95% of cases.

secondary hypertension

high blood pressure caused by the effects of another disease

Can patients be asymptomatic for years, if they have hypertension?

Yes

ADH functions

decrease urine volume output and cause vasoconstriction

RAAS function

vasoconstriction

HTN, Stage 1 Range

SBP 130-139 or DBP 80-89

HTN, Stage 2

SBP ≥ 140 or DBP ≥ 90

Elated BP

SBP 120-129 and DBP < 80

HTN: Goal for pts who are >60 years

<150/90

HTN: Goal for pts who are <60 years

<140/90

When treating HTN, before increasing dose you should

try a different medication group (pharmacological class)

ACE-I stands for

Angiotensin-converting Enzyme Inhibitors

ACE-I meds typically end in

-pril

ACE-I side effects

Cough, hyperkalemia, angioedema

Black box for ACE-I

known to cause injury or death in fetus

ARB stands for

Angiotensin II Receptor Blockers

ARB meds typically end in

-sartan

ARB side effects

Angioedema, hyperkalemia, acute renal failure

Black box for ARB

known to cause injury or death to fetus

Calcium Channel Blockers meds can end in

-dipine

Calcium Channel Blockers

agents that inhibit the entry of calcium ions into heart muscle cells, causing a slowing of the heart rate, a lessening of the demand for oxygen and nutrients, and a relaxing of the smooth muscle cells of the blood vessels to cause dilation; used to prevent or treat angina pectoris, some arrhythmias, and hypertension

Do not take ______ with Calcium Channel Blockers.

macrolide antibiotics (can lead to shock)

Macrolide Antibiotics

erythromycin, clarithromycin, azithromycin

Antiadrenergic

blocks the neurotransmission of the sympathetic nervous system (decreases HR, force of contraction, and CO)

Alpha1 adrenergic receptor blockers

Dilate blood vessels & decrease peripheral vascular resistance

alpha 1 adrenergic receptors blocker examples

doxazosin, prazosin, terazosin (-osin)

Alpha 2 receptor agonists

inhibits norepinephrine which decreases BP

Beta Blockers end in

-olol

Black Box for Beta Blockers

titrate down to prevent rebound angina, MI, or ventricular arrhythmias

Thiazide diuretics

Hydrochlorothiazide (HCTZ)

Thiazide diuretics function

Block Na reabsorption; Increase K and H2O secretion

Potassium sparing diuretics

Spironolactone (Aldactone)

Potassium sparing diuretics function

Excrete Na and retains K

Loop Diuretics

Furosemide (Lasix)

Loop Diuretics function

inhibit reabsorption of Na+,
K+ and Cl- in the ascending loop of Henle (can cause hypokalemia)

direct acting vasodilators

nitroprusside (IV only); hydralazine

When to use direct acting vasodilators?

HTN Emergencies

Nurses should monitor for _______ when patients are on hypertensive medications.

bradycardia, orthostatic hypotension, and I&O (electrolytes)

Automaticity

ability of the heart to generate an electrical impulse

Conductivity

ability of cardiac tissue to transmit electrical impulses

SA node has the fastest rate of?

automaticity

Ectopic beat (ectopic focus)

Impulse origination other than in SA node (serious)

Possible causes of ectopic beats

Hypoxia, ischemia, hypokalemia

T or F: Antidysrhythmic drugs can worsen existing dysrhythmias, or may cause new dysrhythmias.

True

Name two non-pharmacological treatments of arrhythmias

Pacemaker; cardioversion; defibrillation; radiofrequency catheter ablation

Sodium Channel blockers

blocks the opening of sodium channels; now rarely used for arrhythmias

Sodium Channel blockers can treat...

atrial dysrhythmia and supraventricular tachycardia.

The sodium channel blocker MOA depends on...

its class (IA, IB, or IC).

Sodium Channel Blockers side effects

arrhythmias, bradycardia, and hypotension

Examples of sodium channel blockers

quinidine; lidocaine

Nursing concerns of sodium channel blockers

interfere with anticoagulants and caution when giving to pts with airway or breathing issues.

Most arrhythmia pts need to be on some kind of...

anticoagulant.

Beta Blockers

decrease cardiac excitability, cardiac workload and oxygen consumption (also decreasing automaticity and HR)

Beta blockers help manage...

dysrhythmia from excessive SNS stimulation (post MI)

Beta blockers side effects are...

bradycardia, hypotension, dizziness, and syncope

What happens if you abruptly stop beta blockers?

rebound hypertension/tachycardia/dysrhythmias

Which beta blocker is used for dysrhythmias?

propranolol

Nursing concerns for beta blocker

Verapamil can increase chance for HB

Erectile dysfunction can result from which heart medicine class?

beta blockers

Potassium Channel Blockers

Prolong the refractory period of the heart

Potassium channel blocker side effects

Pulmonary toxicity (IV), Hepatotoxicity

Potassium channel blockers example

amiodarone