Cardiac failure

 

The inability of the heart to maintain sufficient cardiac output in the presence of normal venous return.

 

Incidence is approx 10 per 1 000 over 65

 

The prognosis of heart failure is poor, 5 year mortality 26–75% from disease progression or sudden death. Approx 50% of individuals with severe failure die within 2 years

 

Left ventricular failure

 

Causes

Ischaemic heart disease.

Hypertension, (increases after-load)

Cardiomyopathy.

Mitral or aortic valve disease

Aortic stenosis.

Abnormal rhythms, e.g. atrial fibrillation.

Anaemia.

Volume overload, (increaser pre-load)

Constrictive pericarditis (inhibits ventricular filling)

 

Clinical features

May start as a left or a right heart failure.

Reduced cardiac output – fatigue, exertion dyspnoea.

Venous congestion leads to systemic congestion with organ failure and pulmonary oedema, exertion dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea.

Crackles at the lung bases

Pulmonary oedema if severe

Tachycardia.

Cardiomegaly.

Crackles at the lung bases leading on to pulmonary oedema.

Anorexia

Nausea related to distension

Eventual hypotension.

 

Observations

BP, observe for lowering of systolic pressure and narrowing of the pulse pressure

Assess peripheral pulse regularly          

Look out for signs of reduced tissue perfusion

Note neck vein filling

Assess effectiveness of drug therapy

 

Investigations

CXR.

ECG.

FBC LFT U+Es.

Thyroid function.

Cardiac enzymes.

Echocardiography.

Exercise testing.

 

Treatment principles

Treat the cause.

Consider, IHD, hypertension, diabetes mellitus, cholesterol, obesity.

No smoking.

Dietary modifications.

Avoid large meals.

Weight reduction.

Salt restriction.

Alcohol is a negative inotrope.

Endurance exercise when well.

Rest during exacerbations.

Prevent  complications of immobility

 

 

ACE inhibitors

Inhibit formation of angiotensin II.

Lower systemic arteriolar resistance.

Reduction in afterload.

Allowing stroke volume and cardiac output to increase.

Renovascular resistence is reduced increasing renal perfusion.

This increased natriuresis.

Removal of angiotensin II`s stimulatory effect on aldosterone also promotes natriuretic effect.

Excess body fluids are lost which reduces venous return.

Venodilation effect increases venous capacity and further reduces pre-load.

 

Diuretics

Increase urine volumes.

Decrease systemic bloating.

Decrease pulmonary oedema.

 

Digoxin

Cardiac glycoside.

Inhibit action of the Na+ / K+ ATP–ase pump.

This increases Ca+ ions.

Causes positive inotropic response.

Increasing cardiac output.

Reduces residual volumes.

Reduces cardiac distension.

Muscle fibre length decreases allowing them to obey Starling’s law further increasing contraction.

 

Antiarrhythmics

 

Acute LVF

 

Aetiology

Usually post MI with large muscle loss. 

Acute valve failure.

Rupture of the intraventricular septum.

Obstruction second to PE.

Tamponade.

 

Features

Acute pulmonary oedema.

(In acute there may be a normal sized heart)

 

 

Right heart failure

 

Aetiology

Most commonly occurs second to LVF.

Chronic lung disease (cor pulmonale).

Pulmonary embolism.   

Tricuspid disease.

Pulmonary semi-lunar valve disease.

Left to right shunts.

Isolated RV myopathies or infarction.

 

Symptoms in RVF

Fatigue.

Breathlessness.

Nausea related to distension.

Fluid accumulation in areas drained by systemic veins.

 

Signs in RVF

Jugular venous distension

Tender smooth hepatic enlargement

Pitting oedema

Development of free abdominal fluid

Cardiomegaly

 

 

Rheumatic fever

An inflammatory disease which occurs in children and young adults (usually 5 - 15 years) as a result of group A Streptococci.

 

Probably an autoimmune reaction to the bacteria.

 

50% of those who have the disorder associated with carditis develop rheumatic valvular disease after 10 - 20 years

 

Maintain good oral hydgine

 

Mitral stenosis

Usually caused by rheumatic fever

Lumen of valve may be reduced from 5 cm to 1cm

 

Pathophysiology

Stenosis --- left atrial hypertrophy --- increase in pulmonary venous pressure --- increase in pulmonary arterial pressure ---- increased right heart pressure --- Right ventricular hypertrophy --- RV failure

 

Clinical features

AF may occur

Pulmonary oedema

Increased jugular venous pressure

Murmur caused by turbulent blood flow

P wave changes - (double humped)

 

Other valve disorders

Mitral  regurgitation

Aortic stenosis or regurgitation

Tricuspid stenosis or regurgitation

Pulmonary stenosis or regurgitation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MCQs

 

1. Which blood vessels drain blood into the left atrium? Chose 1 answer.

a. Inferior and superior vena cava

b. Pulmonary veins

c. Hepatic veins

d. Renal veins

e. Aorta

f.  Pulmonary artery

 

2. What is the name of the valve between the right atrium and right ventricle? Chose 1 answer

a. mitral

b. bicuspid

c. aortic

d. semi-lunar

e. tricuspid

f. pulmonary

 

3. The most common single cause of heart failure in the UK is; Chose 1 answer

a. Syphilis

b. Diabetes type 1

c. Diabetes type 2

d. Hyperthyroidism

e. Hypertension

f. Viral infection

 

4. Which of the following will increase afterload Chose 1 answer

a. Venoconstriction

b. Venodilation

c. Arterial vasodilation

d. Arterial vasoconstriction

e. Hypovolaemia

f. Sepsis

 

5. Starling’s law of the heart indicates that; Chose 2 answers.

a. Cardiac output is determined by venous return

b. Venous return is determined by cardiac output

c. Myocardial contraction is determined by myocardial stretching

d. Increases heart rate will cause hypertension

 

6. Which of the following may increase HDLs? Chose 3 answers.

a. Exercise

b. Moderate alcohol consumption

c. Smoking

d. Eating more monosaturated fats

e. Eating more polysaturated fats

f. Psychological stress

g. Poorly managed diabetes mellitus

h. Hypothyroidism

 

7. Which of the following may increase LDLs? Chose 4 answers.

a. Exercise

b. Moderate alcohol consumption

c. Smoking

d. Eating more monosaturated fats

e. Eating more polysaturated fats

f. Psychological stress

g. Poorly managed diabetes mellitus

h. Hypothyroidism

 

8. Which of the following is an effect of left ventricular failure? Chose 2 answers.

a. There is an increase in cardiac output

b. Cardiac output is maintained at normal levels

c. There is a decrease in cardiac output 

d. Pulmonary oedema may present as a complication  

e. Cardiac preload will be decreased

 

9. Increased jugular venous pressure is an indicator of; Chose 1 answer

a. Right ventricular failure    

b. Left ventricular failure    

c. Coronary atherosclerosis

d. Tricuspid stenosis

e. Cerebrovascular disease

 

10. One of the first complications of right ventricular failure will be: Chose 1 answer

a. Dehydration

b. Skin rashes

c. Chest pain

d. Ankle oedema

e. Hepatic congestion

f. Pulmonary oedema

 

11. In pulmonary heart disease the blood pressure in the pulmonary artery will be; Chose 1 answer.

a. Higher than normal

b. Lower than normal

c. The same as normal

d. Usually about 120 / 80 mmHg

 

12. ACE inhibiting drugs will; Chose 3 answers.

a. Increase blood pressure

b. Decrease blood pressure

c. Reduce the secretion of rennin from the kidneys

d. Lead to peripheral vasoconstriction

e. lead to peripheral vasodilation

f. Inhibit the formation of angiotensinogen