INTERNAL MEDICINE

Heart failure

Definition ‘Failure of the heart to maintain a cardiac output

sufficient to meet the metabolic demands of the body’ Physiology

Cardiac Output = Heart Rate X Stroke Volume - Latter is dependent on:

Preload = Left ventricular end diastolic volume i.e. amount of stretch of left ventricle = volume overload

Afterload = Total peripheral resistance = pressure overload

Contractility = Capacity of myocardium to 'respond to' preload and afterload

Heart failure

A)Classification:New York Heart Association Functional Classification

Class I: no limitation is experienced in any activities; there are no symptoms from ordinary activities.

Class II: slight, mild limitation of activity; the patient is comfortable at rest or with mild exertion.

Class III: marked limitation of any activity; the patient is comfortable only at rest.

Class IV: any physical activity brings on discomfort and symptoms occur at rest.

Heart failure

B)Classification of heart failure: 1.Right heart failure 2.Left heart failure 3.Biventricular failure

C) Classification of heart failure: 1.Acute heart failure 2.Chronic heart failure

Heart failure

D) Heart failure is often classified as either systolic or diastolic.

1.Systolic heart failure means,heart muscle cannot pump, or eject, the blood out of the heart very well.

2.Diastolic heart failure means, heart's pumping chamber does not fill up with blood.

Heart failure

Causes: Valve heart disease - approximately 10% of

cases.Aortic stenosis can cause left ventricular hypertrophy due to chronic excessive afterload.

Aortic or mitral regurgitation, ASD, VSD and tricuspid incompetence cause excessive preload.

Heart failure

Causes: Heart failure secondary to myocardial

disease:Coronary heart disease (myocardial infarction (MI) and ischaemia, arrhythmias, e.g. atrial fibrillation, heart block)

Hypertension (increased vascular resistance, often with left ventricular hypertrophy )

Cardiomyopathies

Heart failure

Causes: Other’s Drugs (e.g. beta-blockers, cytotoxics) Toxins (e.g.alcohol) Endocrine (diabetes)

Heart failure

Causes: Other’s Nutritional (e.g. deficiencies ) Infiltrative (e.g. connective tissue disease) Infective (e.g. HIV)

Heart failure

Causes: Other’s Anaemia Pregnancy Arteriovenous malformations

Heart failure

Local change in heart: Chamber enlargement Myocardial hypertrophy Increased heart rate

Heart failure

Clinical feature: Dyspnoea and fatigue (may limit exercise

tolerance). Fluid retention (may cause pulmonary or

peripheral oedema). Patients do not necessarily have both, and either

may dominate at any one time. In addition, patients may be depressed or complain of drug-related side-effects.

Heart failure

Clinical feature: When the left ventricle is failing (LVF): dyspnoea,

poor exercise tolerance, fatigue, orthopnoea, paroxysmal nocturnal dyspnoea (PND), nocturnal cough or wheeze.

Right ventricular failure: (RVF) peripheral oedema (up to thighs, sacrum, abdominal wall), abdominal distension (ascites), nausea, anorexia, facial engorgement, pulsation in neck and face (tricuspid regurgitation), epistaxis.

Heart failure

Clinical feature: The patient may look ill and exhausted, with

tachypnoea, cool peripheries, peripheral ± central cyanosis.

There may be a tachycardia at rest, low systolic BP, a displaced apex (LV dilatation) or RV heave (pulmonary hypertension)and a raised JVP.

Heart failure

Clinical feature: On auscultation there may be a gallop rhythm or

murmurs of mitral or aortic valve disease; wheeze , pleural effusions, tender hepatomegaly – pulsatile in tricuspid regurgitation, with ascites and often extensive peripheral oedema.

The peak expiratory flow rate may be reduced but, if it is < 150 litres/min, suspect COPD or asthma.

Right Heart Failure

Causes: Secondary to LVF LD-CB VHD- MS Congenital heart disease- ASD,VSD Pulmonary embolism Myocarditis MI

Left Heart Failure

Causes: Pressure overload- systolic hypertension, aortic

stenosis Volume overload- mitral regurgitation, aortic

regurgitation Ventricular inflow obstruction- mitral stenosis Reduced ventricular hypertrophy- MI, myocarditis

RHF/LHF

Clinical feature of RHF and LHF: See previous slide

Right Heart Failure

Investigation: RHF CXR P/A view ECG Echocardiography

Left Heart Failure

Investigation:LHF CBC RFT CXR P/A view ECG Cardiac enzymes Echocardiography Cardiac MRI Angiogram

Heart failure

Management of heart failure: A)General management- Diet Restricted alcohol Restricted smoking Exercise

Heart failure

Management of heart failure: B)Drug management- 1.Diuretics- frusemide, potassium spirolactone 2.Vasodilators- ACE inhibitors 3.Inotropic agent- digoxin, dubutamines

Heart failure

Management in acute case:LVF/PE Bed rest in propped up position O2 inhalation Inj:morphine 10 mg iv Frusemide 40-80 mg iv Glyceryl trinitrate Dubutamine 2.5-10 μg/kg/min Aminophylline 250-500 mg infused over 10 mins