Heart failure and cardiomyopathy Flashcards
Risk factor for HF
AGE HTN +++ = 39% of HF in men and 59% in women MI Valvular lesions thyrotoxicosis Arrhythmias
Pathophysiology of heart failure
Index event - MI, HTN, Valvular disease –> myocyte injury
Myocyte injury:
- > Neurohormonal activation
- > Peripheral vasoconstriction
- > Fluid retention
- > Decreased contractility
–> progressive heart failure
NYHA Criteria
Class 1 = asymptomatic
Class 2 = Symptoms with exercise
Class 3 = Symptoms during everyday activities
Class 4 = Symptoms at rest
Signs of chronic heart failure
Orthopnoea = most reliable
90% of patients with PCWP >22
What is diastolic heart failure
Disordered filling of the ventricle
Stiffening ventricle –> need for increased pressures to fill
Can be isolated but most commonly with systolic HF
Caused by HTN and HOCM most commonly
Treatment for Diastolic heart failure
NIL RCTs
Avoid fluid depletion and inotropes
Improve relaxation - beta blockers and calcium channel blockers
Rate control AF
Use of BNP for heart failure diagnosis
>400pg/mL = CHF likely <100 = unlikely 100-400 = patients history - LV dysfunction, cor pulmonale or PE = CHF
Reducing heart failure in high risk patients
Risk factor reduction = Treat HTN, Diabetes, hyperlipidaemia
Education
ACE-Is in high risk groups and IHD
Treatment of structural heart disease without symptoms
ACE-Is in all
Beta blockers in IHD cardiomyopathy
Treatment of structural heart disease with symptoms for heart failure
Education Heart failure MDT ACE-Is and beta blockers for all Aldosterone blockers Diuretics = nil survival benefit Digoxin = nil survival benefit but decreases hospitalisations Ivabradine if SR and HR >77 AICD if EF >35% CRT if LBBB
HF with refractory symptoms
Inotropes
LVAD
Transplant
Palliation
Diuretic Resistance
Oral = gut oedema –> reduced uptake
IV resistance = an extension of cardiorenal syndrome –> frusemide infusion or dobutamine/levosemendan
Which is the most potent B blocker?
Carvedilol
Which is the most cardioselective B blocker?
Nebivolol
Side effects of beta blockers?
Dizziness and dyspnoea
Worse in the short term 3 months prior to the onset of improved symptoms
Benefits of beta blockers
Improved morbidity and mortality class 2-3 HF - heart failure and SCDs reduced Class 4 requires stabilization and euvolaemia prior to commencement
Dose related benefits
Which betablockers have evidence
Carvedilol, bisoprolol and nebivolol
Spironolactone and epleronone side effects
Hyperkalaemia
- -> temporary pacing
- -> renal insufficiency
- -> Discontinuation
Must monitor EUCs weekly for the first 4 weeks
Higher doses do not increase benefit
What is the mechanism of action for Spironolactone and epleronone?
Aldosterone antagonist –> inhibits ENaC –> reduced reabsorption of sodium and water in the collecting duct
What is the mechanism of action of ivabradine?
A sinus node funny/sodium channel inhibitor which slows the upstroke of depolarisation –> slower heart rate
Does not have neurohormonal effects
What is the benefit of ivabradine?
Reduces hospitalisations for heart failure in class 2-4 heart failure Reduces mortality for patients with HR <77bpm
NO SUBSTITUTE FOR BETA BLOCKERS
SHIFT trial
What is LCZ696/Entresto
Valsartan + sacubitril
What is sacubitril
A neprolysin inhibitor
Sacubitril is a prodrug that is activated to sacubitrilat by de-ethylation via esterases –> inhibits the enzyme neprilysin, a neutral endopeptidase that degrades vasoactive peptides, including natriuretic peptides, bradykinin, and adrenomedullin –> increases these peptides –> blood vessel dilation and reduction of ECF volume via sodium excretion
Which treatments decrease symptoms but don’t improve mortality?
Digoxin and diuretics
What is the mortality rate for advanced heart failure?
Advanced HF = symptoms despite max therapy
10% of CCF patients/yr
25% mortality at 1yr
Lifestyle measures to reduce HF symptoms?
Education Lifestyle changes: - Salt restriction - Water restriction - Weight reduction - Cease smoking - Cease alcohol Rehab programs Manage co-morbidities
Causes of death by NYHA class
Class 2 = Sudden death +++
Class 3 = Sudden death ++ Heart failure +
Class 4 = Heart failure
When is AICD indicated?
Class 2-3 with LVEF <35% with maximal medical therapy
If IHD = must wait at least 40 days
When is CRT indicated?
Class 3-4 with LVEF <35% and QRS > 120ms
Class 2 with LVEF <35% with LBBB + QRS >150
MUST be in SR and have ongoing symtpoms despite optimal medical therapy
Aims to pace the ventricles constantly to prevent MR
What about Bi-Ventricular pacing?
For patient with class1-3 and LVEF<50% Bi-V reduces death and HF hospitalizations
Indications for Cardiac transplant?
Refractory class 3-4 HF
VO2 max <14 mL/kg/min + anaerobic metabolism
Severe ischaemia not amenable to treatment
Recurrent refractory ventricular arrhythmias
Disadvantages of Transplantation?
Donor shortage
Long waiting times
10-20% wait list mortality
Risks of immunosuppression
Risk of rejection
Mortality of transplant patients?
4%/yr
Pathophysiology of HOCM?
Abnormal hypertrophy any any part of the ventricle
+/- LV outflow obstruction
+ Diastolic dysfunction +++
Diastolic dysfunction –> LA dilation –> AF
Presentation of HOCM?
Asymptomatic Palpitations and syncope SCD Endocarditis Angina
Signs of HOCM?
Ejection systolic murmur which varies with contractility, preload and afterload
Mitral regurgitation
ECG = T wave inversion of Lateral leads
Principles of management of HOCM
Treat heart failure
- Beta blockers
- ACEI-s
- DO NOT use digoxin and diuretics
Alcohol septal ablation
Myomectomy
Prevent SCD
- Beta blockers
- AICD
Screen relatives
Risk factors for SCD in HOCM
Family history Recurrent syncope NSVT Severe LVH Severe obstruction Abnormal BP response with exercise Specific genotype - ARG719TRP
Restrictive Cardiomyopathy
Predominant right heart failure
Preserved LVEF with diastolic dysfunction
Atria dilated
AV regurg
TREATMENT = transplant and fluid balance
Response usually poor
