Flashcards in Week 238 - Heart Failure Mx Deck (36)
List the 2 main symptom relieving drugs used in heart failure
How does Digoxin work?
Increases contractility force (by increasing calcium movement into myocardium)
Slows electrical conduction through the AV node to slow HR
Give common indications and one contraindication for digoxin
Rapid atrial rhythms e.g. AF, atrial flutter, Atrial tachycardia
Contraindicated in heart block
How do ACEIs work?
Reduce the conversion of angiotensin I to II by blocking ACE produced by the lungs.
Inhibit breakdown of Bradykinin (an inflammatory mediator) we in causes vascular dilatation to increase blood flow
Increases preload and afterload!
What is special about Captopril besides being the very first ACEI?
The only ACEI used in paediatrics now
Give at least 3 contraindications for ACEIs
- aortic or mitral stenosis
- bilateral renal artery stenosis
- creatinine >220
- pregnancy. - hereditary/idiopathic angioedema
What stimulates renin release from the kidneys?
Reduced blood flow through renal arteries
Where in the kidneys is renin released from?
List 2 indications for ACEIs besides HF
1st line anti-hypertensive >55
Define the term preload
Tension on the myocardium (heart walls) when filled with blood I.e. End diastole
Define the term afterload
Tension/stress on the heart walls during contraction
What must you monitor 7-10 days after starting ACEIs?
Renal function (U&Es) as if creatinine raises too high (>~300) must stop
Which two Angiotensin II Antagonists (ARBs) have most evidence for benefit in HF?
What 4 other meds is an ARB usually added to in HF and what does it add therapeutically to the mix?
ACEIs, diuretics, digoxin and beta-blockers
It is cardioprotective
What is the most commonly used mineralcorticoid receptor blocker /aldosterone antagonist in HF?
What adverse effect can Spironalactone (and digoxin) have in men and how can it be reduced?
Gynaecomastia and breast pain due to the steroid nucleus (pharmacologically)
Eplerenone has less effect in this respect
How do beta blockers act?
By reducing vasoconstriction (they effect beta-adrenoceptors have in peripheral vessels)
Which beta blockers have most evidence of benefit?
In what circumstance is labetalol particularly indicated?
Reducing HTN in pregnancy (acts as both alpha and beta adrenoceptor blocker)
List at least 3 contraindications for beta-blockers
Asthma (and severe COPD)
Cardiac conduction defects (e.g. Heart block as with digoxin)
Severe peripheral vascular disease
How does Ivabradine work?
Slows heart rate in sinus rhythm (NOT AF) by inhibiting If "funny" channel in sinus node
By slowing the HR is reduces the oxygen demand on the myocardium (used in angina Tx also)
What class of drug is the only one that can be prescribed in diastolic heart failure with any confidence?
How does Spironalactone act?
It's a potassium sparing diuretic
List the main disease-modifying pharmacological treatments used in the management of (systolic) heart failure
Angiotensin II Receptor Blockers/antagonists (ARBs)
Mineralcorticoid Receptor Antagonists
Name 2 novel anticoagulants used in the prevention of thrombosis in AF instead of warfarin. What is the the major advantage over warfarin?
Advantage: monitoring of INR is unecessary
What are the two most important medications to put someone on newly diagnosed with LVF i.e. Have prognostic benefit?
ACEIs and Beta-Blockers
(Only need to add diuretics / digoxin when relevant Sx present e.g. Swelling and rapid or rapid and irregular atrial rhythms)
What two important pieces of advice / information must you discuss with patients newly started on HF medications?
To come back if any adverse side effects appear e.g. Hypotension, cough
Inform them that they will unlikely notice any/much benefit once the medications are started but that they are intended to benefit them long term
Which 2 loop diuretics are used in LVHF?
Furosemide and Bumetanide
If symptoms persist after introduction of ACEIs or ARBs and beta-blockers (ignoring loop diuretics) what other medications might a specialist add to the prescription?
Isosorbide mono- or dinitrate and hydralazine
Ivabradine or Digoxin (depending on whether or not in sinus rhythm)
Besides reducing oedema how does furosemide act?
As a vasodilator
Which type of diuretic are used mainly in HF in the UK?
Loop (furosemide and Bumetanide)
Thiazide diuretics used more in controlling HTN
Where do Loop and Thiazides diuretic act respectively?
Loop - loop of Henle
Thiazides distal convoluted tubule
(Both act to reduced sodium resorption)
Give 4 side effects of thiazide diuretics?
Electrolyte disturbance (low sodium and potassium Na/K transporter)
Gout (high urate)
(Loop low K too but not as severely)
If thiazides (or thiazide related meds) are used in HF which do NICE recommend?
Chlortalidone (non-thiazide) -longer duration of action
Indapamide - less metabolic disturbance
Bendroflumethiazide only if pt already on
How do opiates such as diamorphine and morphine help in the management of Acute LVF?
Acute LVF can be very frightening and is an medical emergency
Diamorphine / Morphine can be used to reduce anxiety and alleviate respiratory distress