Med Surg Exam 3 - Cardiac Flashcards
Which two heart chambers pump deoxygenated blood to the lungs?
Right atrium and right ventricle
Which two chambers pump oxygenated blood to the rest of the body?
Left atrium and left ventricle
What are the three layers of the heart?
Endocardium, myocardium, epicardium
What is the rate of conduction for the SA node?
60-100 BMP
What is the rate of conduction for the AV node?
40-60 BPM
What is the rate of conduction for the Bundle of HIS?
20-40 BPM
What is the rate of conduction for the Purkinje fibers?
Less than 20 BPM
What are the 3 major sequential events for cardiac cycle?
Diastole, atrial systole, ventricular systole
What is ejection fraction?
The percent of end diastolic volume ejected with each heart beat from the left ventricle
What is cardiac output
The amount of blood pumped by the ventricles in L/min
What is the normal range of CO
4-6 L/min
What is the formula for CO
CO = SV x HR
What is stroke volume
The amount of blood ejected with each heartbeat (60-130 mL)
What factors affect stroke volume?
Preload, Afterload, and Contractility
2 factors that affect afterload
systemic vascular resistance and pulmonary vascular resistance
How could preload be increased
Blood products and crystalloids
How can preload be decreased
Diuretics, nitrates, morphine
What increases afterload
Vasopressors and dopamine
What decreases afterload
Nitroprusside, ACE inhibitors, ARBs
What increases contractility
Digoxin and dobutamine
What decreases contractility
Beta blockers and calcium channel blockers
What heart sound makes a ‘lub’
S1
Which heart sound makes a ‘dub’
S2
Which heart sound makes gallop sounds
S3 and S4
What does a friction rub sound like?
A harsh, grating sound
What are nursing interventions post cardiac cath?
Observe cath site for bleeding and hematoma, assess peripheral pulses, Allen’s test, cap refill, color, temp, maintain bed rest for 2-4 hours
Define blood pressure
The pressure that blood exerts against the walls of the arteries. Blood pressure increases when the heart beats and decreases when the heart rests
What is the relationship between the kidneys and the cardiovascular system?
Kidneys filter blood. When there is a decrease in cardiac output, there is a decrease in blood in the kidneys, which leads to decreased urine output
Normal blood pressure
Sys <120 Dia < 80
Elevated BP
Sys 120-129. Dia <80
Stage 1 HTN
Sys 130-130 or Dia 80-89
Stage 2 HTN
Sys >/= 140 or Dia >/=90
Which group has the highest prevalence of HTN
African Americans
Non-modifiable risk factors for HTN
Age, Male (until 45, then female at risk after 65), Family history, African American
Modifiable risk factors for HTN
Obesity, sedentary lifestyle, excessive alcohol, sleep apnea, stress, tobacco smoker
Use beta blockers with caution in which patients
asthma
Monitor for what side effects when administering ACE inhibitors
hypotension, hyperkalemia, altered renal function, periorbital and oral edema, cough, proteinuria, neutropenia, orthostatic hypotension
Suffix for ACE inhibitors
-PRIL
Suffix for ARBs
-ARTAN
Side effects and nursing implications for ARBs
hypotension, fatigue, hepatitis, renal failure, monitor liver and kidney enzymes, monitor for angioedema
What is the MOA for alpha adrenergic blockers
Peripheral vasodilation. Used in severe hypertension
S/E of alpha adrenergic blockers
Orthostatic hypotension, weakness, headache, palpitations, headaches, reflex tachycardia
Suffix for alpha adrenergic blockers
-ZOSIN
5 examples of vasodilators that decrease peripheral resistance
Hydralazine, minoxidil, nitroprusside, nitroglycerin, isosorbide dinitrate
MOA of beta blockers
Blocks sympathetic nervous system, decreases HR, lowers BP, reduced O2 consumption during myocardial contraction
Name 2 nonselective (B1 and B2) beta blockers
Propranolol and Carvedilol
Name 3 selective (B1) beta blockers
Acebutalol, Atenolol, Metoprolol
Nursing considerations for beta blockers
Monitor for orthostatic hypotension, avoid in asthmatics, diabetics and heart block. Do not discontinue abruptly or vary administration time. Can mask the signs of hypoglycemia.
Main suffix of calcium channel blockers
-Dipine
Examples of 4 calcium channel blockers
Amlodipine, Nifedipine, Diltiazem, Verapamil
What does the P wave on an EKG represent
atrial depolarization. Usually 0.08 to 0.12 seconds
What does the QRS complex represent
Ventricular depolarization (0.06 - 0.10 sec)
5 step process to interpret rhythm strip
Heart rhythm, Heart rate, P wave, PRI, QRS complex
Normal sinus rhythm (NSR)
Regular rhythm, Rate 60-100, P wave upright, PRI 0.12-0.20, QRS complex less than 0.12
PACs (Premature Atrial Contractions
Irregular rhythm, normal rate (60-100), normal p wave, normal PRI, normal QRS
Which atrial dysrhythmia can cause micro clots to form and release into circulation
Afib
What are some interventions to control heart rate
Anticoagulation, Beta blockers, Cardioversion, Digoxin
Cardioversion fast facts
Consent needed, patient sedated, synchronized with R wave, used for Afib/Flutter/SVT
Defibrillation fast facts
Emergency, unconscious, unsynchronized patient, V-Fib/Vtach
Junctional rhythms originate from
AV node or bundle of HIS
First degree heart block
Everything normal except PRI is greater than 0.20 seconds
Second degree Heart Block - Mobitz Type 1/Weinkebacke
PRI: Longer, longer, drop
Second degree heart block type 2
Regular atrial rate, but ventricular rate is irregular. May have P wave without QRS
Third degree heart block
No relationship between the atria and ventricles
