Heart Failure Flashcards
What is heart failure with reduced ejection fraction
AKA systolic heart failure. Most common form
Left ventricle cannot generate enough pressure to eject blood forward through the aorta
Ejection fraction <40%
What is heart failure with preserved ejection fraction
Aka diastolic HF. Inability of ventricles to relax and fill during diastole leading to decreased filling and cardiac output
Characterized by high-filling pressures
Often the result of left ventricular hypertrophy
How does the SNS compensate for HF?
-Release of catecholamines
-increased HR, myocardial contractility and peripheral vasoconstriction
-Eventually leads to increased cardiac workload and O2 requirements
What do the kidneys do to compensate during HF?
-Kidneys respond to decreased blood flow by producing more renin which will activate the RAAS system
-Sodium and fluid are retained, peripheral vasoconstriction and BP are increased
What does the pituitary gland do in response to HF?
The posterior pituitary gland responds to decreased cerebral perfusion pressure and secretes ADH (causes sodium and water retention) creating increased blood volume in an already overloaded state
What is ventricular dilation?
-ventricles enlarge due to chronically elevated pressure
-Allows for greater filling volumes at first but eventually, muscle fibres are too stretched to contract effectively
-Decreased CO
What is Ventricular Hypertrophy? How does it compensate for HF?
-hypertrophy of myocardial cells increasing cardiac wall thickness in response to overwork + strain
-Initially adaptive but eventually hypertrophic muscle requires more O2 and has poorer contractility
-Coronary artery circulation is poor, dysrhythmias are common
What does BNP do in HF?
-Acts as counter-regulatory system
-regulate renal, cardiovascular and hormonal effect (i.e., increase diuresis, vasodilation, inhibit aldosterone)
-Cardiac decompensation occurs when these mechanisms can no longer maintain adequate CO and tissue perfusion becomes insufficient
What are the primary risk factors for HF?
Coronary artery disease and hypertension
What are the Cardiac Output regulatory mechanisms?
-Pre load, afterload
-Cardiac contractility
-Heart rate
What are the S&S of left sided (REF) HF
-Pulmonary congestion (cough, crackles, wheeze, blood tinged sputum, tachypnea)
-Tachycardia
-Exertional dyspnea
-Cyanosis
-Nocturnal dyspnea, orthopnea
What are the S&S of right sided (PEF) HF?
-Increased peripheral venous pressure
-Ascites
-Enlarged liver and spleen
-Dependent edema
-Distended jugular veins
-Anorexia + GI distress with weight gain
What is EF and what would a decreased EF indicate?
-Indicates the percentage of blood ejected from the left ventricle with each contraction
-EF is Beverly reduced in systolic or REF HF
-Decrease in EF indicates worsening HF
What is a normal EF range?
55-65%
How do angiotensin-converting enzyme inhibitors, such as enalapril work to reduce HF?
a. Cause systemic vasodilation
b. Increase cardiac contractility
c. Reduce preload and afterload.
d. Prevent conversion of angiotensin I to angiotensin II
e. Block sympathetic nervous system stimulation to the heart.
f. Promote the excretion of sodium and water in the renal tubules.
The Dr. Orders:
Furosemide
80 mg IVP now, then 40 mg/day IVP
What is the rationale for changing the route of the furosemide from PO to IVP?
Pt is fluid-overloaded and needs to decrease fluid volume in a short period. Intravenous administration is delivered directly into the vascular system, where it can start to work immediately.
-In HF, blood flow to the entire gastrointestinal (GI) system is compromised; therefore, the absorption
of orally ingested medications may be variable and take longer to work.
What lab tests should be ordered for a pt with HF on furosemide?
a. sodium level
b. potassium level
c. magnesium level
d. coagulation studies
e. serum glucose level
f. complete blood count
g. liver function studies
A, B, C,
What is the reason for ordering the beta blocker carvedilol for a pt with HF?
a. To increase urine output
b. To cause peripheral vasodilation.
c. To increase the contractility of the heart
d. reduce cardiac stimulation from catecholamines
D
Beta-blockers reduce or prevent stimulation of the heart from circulating catecholamines.
A – Diuretics increase urine output
B – ACE inhibitors cause peripheral vasodilation
C – Inotropic medications (i.e. digoxin) increase the contractility of the heart
Which conditions would be contradictory to ordering carvedilol?
Asthma
-Nonspecific (nonselective) beta-blocking drugs may precipitate bronchoconstriction and/or increase airway resistance.
-Therefore, any preexisting respiratory condition such as asthma might be worsened by the concurrent use of any of these medications.
-Other contraindications to Beta blockers include bradycardia and 2nd or 3rd degree heart block
What is the action of digoxin?
Increases cardiac contractility and cardiac output
-cardiac output increases with a subsequent decrease in filling pressures
Digoxin also slows the heart rate
Which findings would indicate an increased possibility of digoxin toxicity?
a. Serum potassium level of 2.2 mEq/L
b. Serum sodium level of 139 mEq/L
c. Apical heart rate of 64 beats/minute
d.
d. Digoxin level 1.6 ng/mL
A
-Low potassium levels can increase the risk for digoxin toxicity
-potassium levels are are affected by loop and thiazide diuretics
-Potassium levels should be monitored carefully during digoxin therapy
What is the normal serum potassium range?
Normal serum potassium is 3.5-5 mmol/L
What is the normal serum sodium range?
Normal serum sodium is 135-145 mmol/L
The nurse takes vitals prior to administering Digoxin. What intervention would the nurse implement after reading a heart rate of 56?
Hold digoxin, contact primary provider
What are symptoms of Digoxin toxicity?
What would a nurse do if suspected digoxin toxicity?
-GI symptoms – nausea, vomiting, diarrhea, abdominal pain
Mental status changes – lethargy, confusion
Visual effects – blurred vision, colour changes (seeing yellow halos)
-If suspected obtain a digoxin level and an ECG
According to MAWDS what teaching would the nurse provide to a HF pt who is being discharged?
Medications: Take as directed, do not skip a dose, and do not run out of medications.
Activity: Stay as active as you can while limiting your symptoms.
Weight: Weigh every morning. Call if you gain or lose 2 kg overnight and 2.5 kg over a 5-day period
Diet: Follow a low-salt diet, and limit fluids to less than 2 quarts or liters per day.
Symptoms: Know what symptoms to report to your provider; report early to prevent readmission.
What conditions do ACE inhibitors put pts at risk for?
low BP, chronic cough, hyperkalemia, decreased Na+, decreased renal function (when renal function already insufficient), low risk for life-threatening angioedema
