Acute LVF and Pulmonary Oedema Flashcards
Describe the pathophysiological process of acute LVF.
A structural (e.g. myocardial ischaemia) or pathophysiological problem (e.g. hypertension) results in the left ventricle being unable to adequately move blood out of the heart.
Describe the process of pulmonary oedema.
The blood in the heart that cannot be ejected in LVF backlogs to the pulmonary circulation causing fluid to leak into the lungs.
What are the causes of acute LVF?
Iatrogenic (aggressive IV fluids given to patients with impaired LV function)
Sepsis
Myocardial infarction
Arrhythmias
How may a patient with acute LVF present?
Rapid onset breathlessness (exacerbated by lying flat)
Type 1 respiratory failure
SOB
Cough (+ Frothy white or pink sputum)
What is type 1 respiratory failure?
Low oxygen without increase in co2
What may be the findings on examination of a patient with acute LVF?
Increased RR Reduced O2 sats Tachycardia Third heart sound Bilateral basal crackles (wet on auscultation) Hypotension (if severe)
What examination findings would suggest right heart failure over left heart failure?
Raised JVP Peripheral oedema (ankles, legs and sacrum)
What investigations may be performed in a patient with suspected acute LVF?
ECG ABG Chest X-ray Routine blood tests BNP blood tests Troponin Echocardiogram
What is B-type Natriuretic Peptide (BNP) and what does a high result indicate?
This is a hormone released from the cardiac ventricles when the myocardium is stretched beyond the normal range.
A high result indicates that the heart is overloaded with blood beyond its normal capacity.
How does B-type Natriuretic Peptide (BNP) normally function?
BNP acts to relax the smooth muscle in the blood vessels thus reducing the systemic vascular resistance. It also acts on the kidneys as a diuretic to promote the secretion of fluid.
What is the evaluation of the specificity/sensitivity of B-type Natriuretic Peptide (BNP)?
It is a sensitive, but not specific test.
What are causes of a raised B-type Natriuretic Peptide (BNP)?
Acute LVF Tachycardia Sepsis Pulmonary Embolism Renal Impairment COPD
What is the main measure of the left ventricular function?
Ejection fraction
What is the ejection fraction and what is the normal value?
The percentage of blood in the left ventricle squeezed out of the with each contraction.
A value of >50% is considered normal
What are the chest X-ray findings in acute LVF and pulmonary oedema?
Cardiomegaly Upper lobe venous diversion Bilateral pleural effusions Fluid in inter-lobar fissures Fluid in septal lines (Kerley lines)
