Heart failure: Difference between revisions

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'''Heart failure''' is a clinical syndrome where the patient has symptoms and/or signs of insufficient [[cardiac output]] and/or backwards congestion. This is due to an underlying decrease in systolic or diastolic function of the heart.
<section begin="clinical biochemistry" />'''Heart failure''' is a clinical syndrome where the patient has symptoms and/or signs of insufficient [[cardiac output]] and/or backwards congestion. This is due to an underlying decrease in systolic or diastolic function of the heart.<section end="clinical biochemistry" />


Decreased systolic function refers to decreased ability of the heart to eject blood, reflected as a decreased left ventricular [[ejection fraction]] (<abbr>LVEF</abbr>, usually shortened to simply EF), called '''heart failure with reduced ejection fraction''' (HFrEF). Decreased diastolic function refers to decreased ability of the heart to fill with blood, called '''heart failure with preserved ejection fraction''' (HFpEF).
Decreased systolic function refers to decreased ability of the heart to eject blood, reflected as a decreased left ventricular [[ejection fraction]] (<abbr>LVEF</abbr>, usually shortened to simply EF), called '''heart failure with reduced ejection fraction''' (HFrEF). Decreased diastolic function refers to decreased ability of the heart to fill with blood, called '''heart failure with preserved ejection fraction''' (HFpEF).
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Echo can also give valuable information on the etiology. It can show valvular abnormalities, hypertrophy, regional hypo/akinesia (due to infarction), etc.
Echo can also give valuable information on the etiology. It can show valvular abnormalities, hypertrophy, regional hypo/akinesia (due to infarction), etc.
 
<section begin="clinical biochemistry" />
=== Natriuretic peptides ===
=== Natriuretic peptides ===
The most important biomarkers for heart failure are the [[Natriuretic peptide|natriuretic peptides]], <abbr>[[NT-proBNP]]</abbr> and BNP. Of these, NT-proBNP is the most used. These biomarkers have high negative predictive value, so NT-proBNP in a normal range makes HF very unlikely. They also have prognostic value and value in monitoring progression.
The most important biomarkers for heart failure are the [[Natriuretic peptide|natriuretic peptides]], <abbr>[[NT-proBNP]]</abbr> and BNP. Of these, NT-proBNP is the most used. These biomarkers have high negative predictive value, so NT-proBNP in a normal range makes HF very unlikely. They also have prognostic value and value in monitoring progression.


The level of NT-proBNP correlates with the severity of the HF, and a high value is associated with a worse prognosis. However, while it’s a sensitive biomarker, it’s not a specific one. NT-proBNP can be elevated in other conditions, like [[Chronic kidney disease|renal failure]], [[pulmonary embolism]], etc.
The level of NT-proBNP correlates with the severity of the HF, and a high value is associated with a worse prognosis. However, while it’s a sensitive biomarker, it’s not a specific one. NT-proBNP can be elevated in other conditions, like [[Chronic kidney disease|renal failure]], [[pulmonary embolism]], etc. NT-proBNP can be false negative in HFpEF.
 
Brain natriuretic peptide (BNP) is a hormone produced in the ventricles (initially discovered in the brain, hence the name). It increases natriuresis (sodium excretion in the kidneys) in response to pressure and volume overload in the ventricles, which occurs in heart failure.  


=== Electrolytes ===
Hyponatraemia is a common feature in heart failure, due to reduction in circulating blood volume from oedema. This increases ADH secretion, giving hyponatraemia. Hyponatraemia also increases due to natriuretic peptide secretion.
<section end="clinical biochemistry" />
=== ECG ===
=== ECG ===
There are no specific ECG findings for heart failure, but the ECG is abnormal in more than 90% of cases of LV systolic dysfunction. Findings may include conduction abnormalities, arrhythmias, ST-T changes, etc.
There are no specific ECG findings for heart failure, but the ECG is abnormal in more than 90% of cases of LV systolic dysfunction. Findings may include conduction abnormalities, arrhythmias, ST-T changes, etc.