Congestive Cardiac Failure

Question 1

Define congestive cardiac failure and list the common causes?

Answer 1

The impaired ability of the heart to function as a pump to support physiological circulation due to any structural or functional cardiac abnormality. Congestive heart failure often refers to when rt sided heart failure occurs following lt sided heart failure. Also known as biventricular cardiac failure.

The most common cause is coronary/ischaemic heart disease.

Other causes include:
Cardiomyopathy.
Hypertension
Valvular heart disease 
Arrhythmias
Drugs

Question 2

Describe the typical signs and symptoms of CCF? What is likely to be the presenting complaint in a history?

Answer 2

Breathlessness (on exertion/at rest), orthopnoea, paroxysmal nocturnal dyspnoea.

LVF:

Dyspnoea and fatigue (may limit exercise tolerance).
Fluid retention (basal crackles)
Orthopnoea.
Paroxysmal nocturnal dyspnoea (PND).
Nocturnal cough or wheeze.
Nocturia, cold peripheries, weight loss and muscle wasting.

Right ventricular failure (RVF):

Peripheral oedema
Abdominal distension (transudate ascites)
Hepatomegaly (due to back pressure)
Facial engorgement
Raised JVP (may indicate tricuspid regurgitation)
Epistaxis (nose bleeds)

Systemic sx:
Nausea
Anorexia

Question 3

Describe the general management of heart failure?

Answer 3

Risk Factor Management:

• Diet and exercise (restrict salt intake, and reduce fluid intake in severe disease, low intensity exercise)
• Smoking cessation.
• Treat hypertension, hyperlipidaemia, arrythmias etc.

Question 4

Describe the pharmacological management of heart failure?

Answer 4

1st line: Beta Blockers (rate control) + ACE inhibitor

Diuretics to reduce the circulating volume. (To monitor affect weigh patients daily, same time each day)

Furosemide: loop diuretic (causes potassium loss)

Vasodilators:

ACEI (ramipril). Angiotensin converting enzyme inhibitor prevents formation of angiotensin II which causes vasoconstriction. Therefore reduces BP, reduce venous pressure and return therefore less strain on the heart. Thought to protect against cardiac remodelling.

Alternative to ACEI is a angiotensin II receptor antagonist (Losartan)

Second line is with:

• Long acting nitrates.
• Aldosterone antagonist (spiranolactone)

Other mechanisms:

Digoxin:

Increases contractility, reduced circulating renin, useful anti arrhythmic.

Provides symptomatic relief but not proven to reduce mortality.

Narrow TI and renally excreted therefore use with caution in renal failure.

Question 5

Describe the mechanism of action of digoxin?

Answer 5

Inhibits Na+/K+ ATPase.
Build up of intracellular Na+.
Intracellular Na+ exchanged for Ca++ increasing contractility.

Digoxin also improves baroreceptor responsiveness therefore in response to the increased conractility baroreceptors cause vasodialtion of vessels and causes there to be a reduction in renin release.

Question 6

What are the common side effects of beta blockers, diuretics and ACEI?

Answer 6

Beta Blockers: dizziness, tiredness, bradycardia

Diuretics: postural hypotension, nausea, stomach upset

ACEI: 1st dose postural hypotension, dry cough

Question 7

What are the investigations used to diagnose the cause of a persons CCF?

Answer 7

ECG: looking for signs of ischaemia, arrhythmias and LVH

CXR: cardiomegaly

Echocardiography: Ejection fraction

• greater than 50% = normal
• 40-50% = moderate
• less than 35% = severe

Raised BNP rarely used now

Question 8

What is cor pulmonale?

Answer 8

Respiratory disease leading to increased resistance to blood flow in the pulmonary circulation, which then results in impaired right ventricular function.

Question 9

What is the mean pulmonary arterial pressure need to be for it to be cor pulmonale?

Answer 9

20mm/hg or higher

Complete right ventricular heart failure ensues if pressure is greater than or equal to 40mm/hg.

Question 10

What is the pathophysiology behind cor pulmonale?

Answer 10

Thought to be most commonly due pulmonary vasoconstriction due to:
-Chronic hypoxia
OR
-Chronic hypercapnoea

Other causes are anatomic disruption of the pulmonary vascular bed due to primary lung disease aka pulmonary fibrosis, emphysema.

Lastly it can be cause by secondary polycythaemia

Question 11

What are the symptoms of cor pulmonale?

Answer 11

Right heart failure symptoms aka oedema, fatigue etc.

Also dyspnea particularly at rest but also worse with exertion. A worsening non productive cough, (may be productive if they have underlying COPD).

Question 12

How is cor pulmonale investigated?

Answer 12

Standard tests: 
ECG
Bloods (FBC/UEs/LFTs)
ABG
CXR

Extra tests:

• Brain natriuretic peptide (BNP) assay (elevated BNP levels have been shown to correlate with raised pulmonary artery pressures and presence of cor pulmonale)
• Doppler heart scan to assess heart size
• Right heart catheterisation (gives accurate measurements of pulmonary pressure however may be poorly tolerated in frail patients)

Question 13

How is cor pulomale treated?

Answer 13

Heart failure treatment.

If preciptating factor treat this to try and minimise damage: aka if due to an exacerbation of COPD

Long term oxygen therapy (LTOT): has been shown to improve quality of life and survival in patients with severe chronic hypoxia due to lung disease as it slows the progression into cor pulomnale.