Congestive heart failure Flashcards by Namood Waseem

What is atherosclerosis?

The process of progressive thickening and hardening of the walls of medium and large-sized arteries as a result of cholesterol deposition

Main pathological condition that causes ischaemic heart disease

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How can atherosclerosis cause a heart attack?

atheroma/plaque narrows lumen
patients experience angina
atheroma is very thrombogenic
if blood comes into contact thrombus/clots can form which can completely occlude the artery
it will cause heart attack/acute myocardial infarction

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What are non-modifiable Cardiovascular Disease Risk Factors?

Age
Male sex
Family History
Low Birth weight
Premature Birth

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What are modifiable Cardiovascular Disease Risk Factors?

Hypertension
Smoking
Diabetes mellitus
Hypercholesterolemia
Obesity
Physical inactivity

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Define heart failure?

“A complex of symptoms—shortness of breath, fatigue, and congestion
Due to an impairment of the heart’s ability to (contract) empty* or (relax) fill* properly,
leading to inadequate perfusion of tissues during exertion (causes forwards symptoms), and retention of fluid (causes backward symptoms)”

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What are some causes of heart failure?

• Decreased contractility, can be due to
o Coronary heart dis.
o Cardiomyopathies: Viral myocarditis 
o Drug: ß-adrenergic blockers
o Arrhythmias

• Increased Afterload
o Hypertension
o Valvular disease
o HOCM (hypertrophic obstructive cardiomyopathy)

• Increased Output
o Anaemia
o Hyperthyroidism
o AV shunts

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What is Acute Decompensation?

Means the patient had been treated, symptoms resolved but there’s a reappearance of symptoms

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What can cause acute decompensation?

Discontinuation of treatment
ACS (new event)
Arrhythmias (AF)
Infection
Anaemia
Pulmonary Embolism

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How does the New York Heart Association (NYHA) classify heart failure?

Class I
• No limitation of physical activity
• Ordinary physical activity does not cause SOB (dyspnoea) or fatigue

Class II
• Slight limitation of physical activity
• Ordinary physical activity result in dyspnoea or fatigue

Class III
• Marked limitation of physical activity
• Less than ordinary physical activity result in dyspnoea or fatigue

Class IV
• Inability to carry out any physical activity without discomfort
• Symptoms are present at rest

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How is heart failure diagnosed?

NT-proBNP (ANP derivative) – measured in the urine, if <400 ng/L then HF is unlikely
ECHO cardiogram (ultrasound of heart): can show HFrEF (heart failure with reduced ejection fraction) or HFpEF (heart failure with preserved ejection fraction)
Cardiac MRI (CMR)
Other tests: ECG, CXR, U&Es, ABGs, D-dimer
Look for cause(s) of decompensation: Troponin for ACS, ECG for Arrhythmias, etc..

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What is ejection fraction?

Ejection fraction (EF) is a percentage of how much blood the left ventricle pumps out with each contraction.
EF of 60% means that 60% of the total amount of blood in the left ventricle is pushed out with each heartbeat – 50% is normal
EF also called Fractional shortening

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What are the types of HF

• Failure of filling of blood:
o Aka Diastolic HF in the past
o HFp EF (Heart failure with preserved ejection fraction >50%)
o HFpEF patients are older, female, hypertension, obesity, anemia, and AF

• Failure of ejection of blood:
o Systolic HF
o HFr EF (Heart failure with reduced ejection fraction ≤40%)

• HFmrEF (mid-range ejection fraction) – in between normal of 50 and abnormal of 40 (41-49%), now name changed to mildly reduced ejection fraction

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Aims of heart failure treatment?

Removal of the underlying or precipitating causes
Improving survival & reducing mortality
Relief of symptoms (& Improvement in quality of life)
Prevention of re-admissions to hospital, recurrent ischaemic events, and further deterioration in left ventricular function

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Ways of treating HF by removal of precipitating causes?

Treatment of hypertension
Correction of valvular lesions
Treat anaemia, thyrotoxicosis, fluid overload, increased dietary salt intake
Improve compliance with treatment
Drugs: beta-blockers, salt-retaining drugs (NSAIDs, steroids) – can cause/worsen heart failure

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What drugs may be used to treat heart failure?

ACE inhibitors
Beta Blockers
Angiotensin receptor antagonists (ARBs)
Aldosterone antagonists
Hydralazine/nitrate
Diuretics
Digoxin
Sacubitril-Valsartan (ARNI)
SGLT2 inhibitors

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How do beta blockers and renin inhibitors work?

Prevent ANG I production - interferes with the RAAS system

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How do ACE inhibitors work?

Prevent ANG II production - interferes with the RAAS system

Reduce angiotensin II levels thus induce arteriolar vasodilatation
Reduce systemic vascular resistance
Reduce norepinephrine release
Decrease sympathetic activity
Decrease aldosterone secretion
Suppress vasopressin release
Increase bradykinin levels

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How do Angiotensin receptor antagonists/blockers (ARBs) work?

Prevent ANG II from binding to its receptor - no vasoconstriction or aldosterone
• Block angiotensin II type 1 receptors

Name a study for ACE inhibitors and say what it showed?

Acute Infarction Ramipril Efficacy (AIRE):

Effect of Ramipril on mortality and morbidity of survivors of acute MI with HF
2006 patients, EF ≤ 35% post-MI
Follow-up average 15 months
Overall mortality significantly reduced 27%
Development of severe heart failure reduced by 23%

Other uses for ACEi?

Hypertension
Post-Myocardial Infarction (LVD)
Diabetic nephropathy
Diabetic retinopathy

Side effects for ACEi?

First dose may cause hypotension
Cough
Angioedema – most dangerous, swelling of lips and tongue
Rash
Neuropathy
Deterioration of renal function (in RAS)

Contraindications for ACEi

Pregnancy & breast feeding
Renal artery stenosis (bilateral, single k)

• Caution with patients that have: 
o Peripheral vascular disease
o Low BP
o High dose diuretic, hypovolaemia
o Age >70 ys
o Creatinine >150µmol/L
o +NSAIDs

Alternatives if ACEi are contraindicated or untolerated?

Other vasodilators: Angiotensin Receptor Blockers e.g. Candesartan, Losartan
Hydrallazine & Nitrates
Angiotensin receptor-neprilysin inhibitor (ARNI )

What study showed ARBs were effective?

ELITE study: (Evaluation of Losartan In The Elderly)
• 722 patients with CHF (congestive heart failure)
• Designed to study effects of losartan on renal function (vs captopril)
• All cause mortality was 46% lower

How do beta-blockers reduce chances of HF?

* Reduce sympatho-adrenergic activity * Reduce afterload * Decrease myocardial oxygen demand – important for patients that have angina * Reduce ventricular remodelling * Reduce renin release * Coronary and peripheral vasodilatation * Negative inotropic effect/direct weaking affect on the myocardium – can make HF worse,

What study shows that beta-blockers are effective for treating HF

``` MERIT-HF: • 39991 patients in USA & Europe • NYHA II- III • Metoprolol-XL 12.5mg up to 200mg od • Total mortality: Decreased by 34% • CV mortality: Decreased by 38% • Sudden death: Decreased by 41% ``` Benefit not clear in class I or class IV

Side effects of beta blockers?

* Fatigue * Sleep disturbances * Bradycardia * Hypotension * Heart failure (start low doses, slowly increase) * Conduction disorders * Bronchospasm * GI disturbances

Cautions & Contraindications for beta blockers?

* Asthma, COPD – can be made worse * Uncontrolled heart failure * Severe bradycardia * Hypotension or shock * Pheochromocytoma (unless with a-blocker) * Peripheral vascular disease

What is a diuretic used for HF?

Spironolactone

How does Spironolactone work?

* Acts through its active metabolite, canrenone | * Blocks aldosterone receptors on the distal convoluted tubule

What study shows spironolactone was effective?

RALES (Randomised Aldactone Evaluation Study) • 1663 patients, severe heart failure (NYHA IV) (LVEF<35%) • Rx ACEi + Loop diuretic ± Digoxin • Spironolactone 25mg - 50mg od • Total mortality : 30% reduction p<0.001 • Cardiac mortality : 31% reduction • Hospitalization: 35% reduction

What are the side effects of spironolactone?

o Gynaecomastia in males (painful) – doesn’t reverse o Testicular atrophy o Menstrual irregularities o Hyperkalaemia (esp. renal impairment

What aldosterone blocking agent is also used for HF?

Epleronone: | • Eplerenone produces less painful gynaecomastia than spironolactone

What study proves epleronone as effective?

EPHESUS study: • 13% reduction in mortality from cardiovascular causes or hospitalization • 21% reduction in sudden death • Can cause hyperkalaemia and renal dysfunction

What does digoxin do?

* Inhibits Na+-K+ ATPase pump, inactivating Na+-Ca2+ exchanger, increasing Ca 2+ * Increases force of contraction • Other effects o Decrease in AV conduction o Increase in vagal activity o Decrease in heart rate

What are the uses of digoxin?

* Slowing ventricular rate in rapid AF (atrial fibrillation) | * Treatment of heart failure in patients who remain symptomatic despite optimal doses of diuretics and ACE inhibitors

Side effects of digoxin

o Nausea, vomiting, arrhythmias, confusion | o Toxicity enhanced by hypokalaemia

What trials show digoxin efficacy?

* Digoxin has no effect on mortality (DIG trial) * Clinical effects are not dramatic * Withdrawal of digoxin may cause clinical deterioration in 1/4 of patients stable on digoxin and diuretic ±ACEi (RADIANCE and PROVED trials)

What do diuretics do in treating HF?

* Only relieve symptoms * Relieve circulatory congestion and pulmonary and peripheral oedema * Reduce atrial and ventricular diastolic pressure * Do not improve LV dysfunction * Little impact on mortality

What are the side effects of Diuretics?

``` • Metabolic effects: o Hypokalaemia (low K)  (arrhythmias) – most dangerous o Hyperglycaemia (high glucose)  (diabetes) o Hyperuricaemia (high uric acid) (gout) ``` • Social disruption o Frequency, urgency, incontinence

How are Hydralazine & Nitrate used for heart failure?

* Hydralazine in combination with nitrate (especially if the patient is of African or Caribbean origin and moderate to severe heart failure [NYHA class III–IV] * V-HeFT (Vasodilator-Heart Failure Trial) - 43% reduction in mortality * A-HeFT (African American-Heart Failure Trial)

What are Non-Drug Therapy of Heart Failure?

- Cardiac-Resynchronization Therapy (RCT) | - Surgery

How does Cardiac-Resynchronization Therapy (RCT) work?

* Using atrial-synchronized bi-ventricular pacing – different pacing wires in ventricles to make the heart work as one unit * Indicated for patients with severe symptoms and intra-ventricular conduction delays i.e. QRS ≥120 msec * Leads to dys-synchronous LV contraction, impaired emptying, MR * Can reduce symptoms, improve functional capacity, reduce hospitalizations and increase survival

How does surgery work?

* Ventricular Assist Devices – a pump put into the left ventricle and aorta * Cardiac Transplantation * Xeno Cardiac transplantation (genetically modified pig heart) 7th January 2022