Cardiology Flashcards
(109 cards)
Pathophysiology of heart failure
Catecholamines, angiotensin, aldosterone, endothelin, cytokines –> neurohormonal activation –> peripheral vasoconstriction –> fluid retention –> decreased contractility
Neurohormonal activation –> myocyte injury –> decreased contractility
Classes of heart failure
NYHA I - no symptoms, even during exercise
NYHA II - reduced physical capacity during medium exercise
NYHA III - severely reduced physical capacity during slight exercise but OK at rest
NYHA IV - symptomatic at rest
TTE for heart failure
LV size, shape, global and regional function
Complications - MR, pulmonary HTN, thrombus
Assessment of diastolic function
MRI for heart failure
Function
Structure
Viability
Composition
Right heart catherisation transportation
R atrium > R ventricle > Main pulmonary artery > PA branch > Pulmonary artery wedge pressure
Definition of HFrEF
Symptoms of HF with LVEF < 50%
Definition of HFpEF
Symptoms of HF, LVEF > 50% and diastolic dysfunction (evidence of high filling pressure and/or object evidence of relevant structural heart disease)
Role of natriuretic peptides
ANP - originated from cardiac atria, released by atrial distension
BNP - originated from ventricular myocardium, released by ventricular overload
CNP - originated from endothelium, released by endothelial stress
BNP physiologically increases with
Age
Females
Post menopause
Treatment for HFpEF
SGLT inhibitors
Diuretics
Angiotensin receptor blockers
Salt restriction, exercise training
Manage comorbidities (AF, HTN, CAD, OSA)
MOA of SGLT2 inhibitors
Blocks reabsorption in PCT –> increases glucose excretion
Outcomes of EMPEROR study
Reduced HF hospitalisations (and CV death to lesser degree) in patients who received empagliflozin and dapagliflozin
Goals of treatment in HF
Prevent diseases causing LV dysfunction
Prevent progression to symptomatic HF
Reduce symptoms
Reverse remodelling
Improve survival
Management of HFrEF
Stage A - high risk, no symptoms
- Risk factor reduction
- Education
- ACE inhibitor
- Treat HTN, DM, hyperlipidaemia
Stage B - structural heart disease, no symptoms
- ACE inhibitor
- B blockers
Stage C - structural disease, previous or current symptoms
- AICD if EF < 35%
- Diuretics
- Aldosterone blockers
- HF rehab
- Ivabradine if HR > 77
- SGLT2 inhibitor
- CRT if LBBB
- Specialised cardiac surgery
Stage D - Refractory symptoms requiring special intervention
- Inotropes
- Transplantation
- Palliation
Four pillars of heart failure
ACEI/ARNi/ARB
Beta blockers
Mineralocorticoid receptor antagonists
SGLT2 inhibitors
ARBS vs ACEI for heart failure
Far less data for ARBS
Strongest data for candesartan, but can use valsartan
Benefits greatest in ACE-I naive patients
Beta blockers proven benefit in CCF
Carvedilol
Bisoprolol
Nebivolol
Long acting metoprolol (succinate)
Evidence for beta blockers in CCF
Demonstrated improvement in mortality and morbidity in class II-IV
Must be stabilised and euvolaemic prior to initiation
Reduction in SCD
Spironolactone in CCF
Higher doses not shown to have greater benefit but have greater adverse effects
Caution in renal impairment
Indications for ivabradine
HR > 70/min (DESPITE adequate beta blocker dose)
If lung disease precludes beta blockers
Beta blockers truly not tolerated - unacceptable symptomatic hypotension, intolerable beta blockers side effects
How does Entresto cause rise in BNP?
Entresto - Valsartan + neprolysin inhibitor (sacubitril)
Causes rise in BNP (as BNP is neprolysin substrate), however causes fall in NT pro BNP
Current indications for Entresto in HRrEF
Add on therapy if NYHA II-IV (symptomatic HF) and LVEF < 40% after 3-6 months of optimal treatment
Practice point if ACEI already commenced and wanting to start Entresto
Need to wait 36 hours after cessation of ACE inhibitor before started Entresto
Role of digoxin and diuretics in HF
Nil effect on mortality
Reduces symptoms