Heart Failure / Oedema

Question 1

What is heart failure?

Answer 1

A condition where the heart does not pump blood around the body as well as it should

Question 2

Symptoms of HF

Answer 2

Dyspnoea (SOB)
Orthopnoea (SOB when lying flat)
Elevated jugular venous pressure
Pulmonary congestion
Peripheral oedema

Question 3

How does HF cause oedema?

Answer 3

When blood is not circulated properly, it backs up causing increased pressure in blood vessels and this forces fluid from vessels into body tissue (fluid retention)

Question 4

What is the difference between diastolic and systolic HF?

Answer 4

Diastolic = impaired cardiac relaxation and abnormal ventricular filling = stiff muscle of ventricle cannot relax normally so less blood fills the ventricle. Heart failure with preserved ejection fraction / HfpEF . EF>50%
Systolic = reduced cardiac contractility. Weakened muscle of ventricle cannot squeeze as well so less blood is pumped out. Heart Failure with reduced ejection fraction / HFrEF. EF<40%

Question 5

How can hypertension cause HF?

Answer 5

HTN forces the heart to work harder than it should to pump blood around the body. Over time, this extra work can make heart muscle too stiff or weak to properly pump blood

Question 6

What is LV failure?

Answer 6

When fluid collects in the lungs, causing pulmonary congestion (fluid backs up in the lungs) causing SOB particularly with activity or lying down. Both systolic and diastolic HF are types of left sided HF due to LV.

Question 7

What is RV heart failure? And what can it cause?

Answer 7

Fluid backs up into belly, feet, legs, causing swelling -> peripheral oedema

Question 8

Is it possible to have left sided and right sided HF at the same time

Answer 8

This is called congestive HF. It is possible to have both at the same time. It usually starts on the left and progresses to right side when left untreated.
Many patients have stable congestive HF. But this can decompensate when a change occurs to their body e.g a patient with congestive HF may be doing well but then developed pneumonia or suffers MI

Question 9

Symptoms of congestive HF

Answer 9

Fatigue
Reduced exercise capacity
SOB
Oedema

Question 10

Causes of congestive HF

Answer 10

Ischaemic heart disease
HTN
Valve disease
AF
Chronic lung disease
Cardiomyopathy
Previous chemo

Question 11

How do you confirm congestive HF

Answer 11

Echocardiogram: will confirm whether diagnosis is correct. Possible findings:
- dilated poorly contracting LV (systolic function)
- stiff, poorly relaxing, often small diameter LV (diastolic function)
- valve disease
- pericardial disease

Question 12

Treatment of congestive HF

Answer 12

• lifestyle modification: smoking, drinking, salt
• take diuretics to decrease fluid within body so heart doesn’t have to work hard to circulate blood through blood vessels
• ACE inhibitors decreases systemic resistance and lowers strain on heart
• nitrates reduce pulmonary oedema and reduce ventricular size
• BB reduces HR to increase CO and EF
• Digoxin increases CO and controls symptoms

Question 13

What is chronic HF?

Answer 13

Inability to maintain adequate tissue perfusion at a normal filling pressure = in order to get enough force beging generated it requires a higher filling pressure ( end diastolic pressure)

Question 14

Common causes of LVHF

Answer 14

Reduced muscle mass following an MI
Exercise workload from HTN or valves disease causing LVH

Question 15

What does LVHF result in

Answer 15

• impaired stroke volume resulting from abnormal calcium regulation and electrical activity ( systolic HF)
• impaired ventricular filling (diastolic HF)
• ventricular arrhythmia causing early sudden cardiac death

Question 16

What happens when patients with HF suffer from lethal cardiac arrhythmias? How do these lethal arrhythmias occur?

Answer 16

Arrhythmias are triggered by delayed after depolarisations (DADs) = depolarisations that occur during diastole, often associated with spontaneous or unsynchronised calcium release events.
Patients commonly develop polymorphic VT, which can degenerate into VF. A definitely shock is required for heart to go back into SR.

Question 17

What alternatives can we offer patients with HF?

Answer 17

When there is evidence of LBBB - QRS duration is broad and essentially depolarisation is delayed from the septum to the lateral wall resulting in mechanical reduction. If we pace, at these two points then we can alter the QRS duration to become narrow again, the heart muscle can pump normally. This is called a **cardiac resynchronisation pacemaker (CRT) ** and is a biventricular pacemaker that shocks both ventricles at the same time so the heart pumps more efficiently.
Other special pacemakers are ICDs (implantable cardiac defibs). These do not improve symptoms but prevents sudden cardiac death by detecting and cardioverting VT/ VF