Cardiac Failure 2: clinical management Flashcards
What should all patients with left ventricular systolic dysfunction receive
- Angiotensin-converting enzyme inhibitor (ACE inhibitor)
- Beta blocker
What should all patients with oedema receive
A diuretic
What do ACE inhibitors do
- reduce salt/water retention and so reduce circulating volume
- Reduce vasoconstriction and manage congestive heart failure by blocking production of angiotensin 2
- Reduce circulating volume by reducing salt/water retention
How should ACE inhibitors be prescribed
In low doses then titrated up
Given at night
What should you monitor when prescribing ACE inhibitors and why
Monitor creatinine/eGFR and potassium ion concentrations before and during treatment because ACE inhibitors can worsen renal function
How do you determine dose of ACE inhibitors
Measure renal function
What are the side effects of ACE inhibitors and how to overcome this
May cause severs hypotension and so you should withdraw the diuretic therapy for a few days before and also tell patient to have the ACE inhibitor at night
-If patient develops a cough, tell them to come back to change the drug
What is renal artery stenosis
Atherosclerotic plaque is in renal artery
What does the kidney do in response to renal artery stenosis
Releases lots of renin to boost blood pressure to improve the blood flow to the kidney
What do AT1 receptor antagonists do and why is this better than an ACE inhibitor
Block the action of angiotensin 2
-Far less likely to give rise to a cough
What does an AT1 receptor antagonist prevent
Vasoconstriction and formation of aldosterone (which increases retention of sodium and water and increases the excretion of K+)
What does angiotensin 2 act as
AT1 receptor
An example of a beta blocker
Bisoprolol
What do beta blockers do
Reduce sympathetic stimulation, heart rate and o2 consumption
How do beta blockers help in atrial fibrillation
Will control rate
How do beta blockers help with the neurohormonal activation
Oppose neurohormonal activation which leads to myocyte dysfunction
What dosage do you give when giving beta blockers
Start with a low dose
What do loop diuretics do
R~educe circulating volume and reduce preload on the heart
what do diuretics relieve
Pulmonary and peripheral oedema
What does spironolactone do
Reverse left ventricular hypertension
What does a positive inotrope do
Increase the force of the heart
What is digoxin used as in heart failure
Positive inotrope
How does digoxin act as a positive inotrope
Inhibits Na+/K+ ATPase
therefore Na+ accumulates in myocytes. It is exchanged with Ca2+ which leads to increased contractility
What activity does digoxin increase
Vagal activity via the CNS
What is heart block and brachycardia beneficial in heart failure with atrial fibrillation
Slowing the heart rate improves cardiac filling
How can you measure the effectiveness of digoxin
Measure the pulse
What are the problems with digoxin
Toxic
Narrow therapeutic window
Anorexia, nausea, visal disturbances
When there is evidence of LV dysfunction, what should you do
Prescribe ACE inhibitor and beta blocker
IF there is oedema what should you prescribe
Diuretic
IF there is evidence of a cough after prescribing ACE inhibitors and beta blockers, what to prescribe
ATRA
If symptoms are persistent even after prescribing beta blockers, ACE inhibitors and ATRA, what should you do
Prescribe:
- Aldosterone antagonist or ATRA
- or Hyrdalazine plus nitrate
If symptoms are persistent after prescribing aldosterone antagonist or ATRA or hydralazine plus nitrate, what should you prescribe
Digoxin
