Acute Heart Failure – Diagnosis
Cardiovascular
Context
- Leading cause of hospitalization for age 65+, with 30-day mortality ~11%.
- Syndrome of impaired ventricular filling and/or ejection:
- Diminished cardiac output and/or volume overload.
- Causes of exacerbation:
- Acute coronary syndrome (ACS).
- Pulmonary embolism.
- Valvular disease.
- Arrhythmia.
- Hypertension.
- Infection (eg. pneumonia, endocarditis, sepsis).
- Diet/medication non-compliance.
Diagnostic Process
- For suspected Acute Heart Failure (AHF):
- Confirm diagnosis.
- Determine cause of exacerbation.
- Diagnostic Tool (Framingham Heart Failure Diagnostic Criteria)
- Recommended Investigations
- ECG:
- High negative predictive value if normal.
- Chest Radiograph (Examples of Findings):
- Normal CXR does not rule out heart failure.
- Cardiomegaly.
- Redistribution (of fluid into upper pulmonary vessels).
- Interstitial edema.
- Kerley-B lines = small, horizontal, peripheral straight lines demonstrated at the lung bases that represent thickened interlobular septa.
- Less commonly referred to:
- Kerley Alines = linear opacities extending from the periphery to the hila.
- Kerley Clines = reticular opacities at the lung base.
- Peribronchial cuffing.
- Hazy contour of vessels.
- Alveolar edema.
- Consolidation.
- Air bronchogram.
- Cottonwool appearance.
- Pleural effusion.
- FAST Ultrasound:
- B lines example (distinct from Kerley B lines).
- Pleural effusion example.
- Cardiac function.
- IVC volume and variability with respiration.
- Echocardiogram:
- Evaluates cardiac function and may determine underlying cause.
- Perform expeditiously when a life-threatening cardiac process is suspected.
- Lab work:
- CBC, electrolytes, urea, creatinine, liver function tests, TSH, glucose
- +/- Troponin
- Often elevated in HF without infarction.
- Elevation indicates worse prognosis.
- BNP or NT-proBNP
- Sensitive but nonspecific – various causes for elevation aside from HF.
- Most recommend use only if uncertainly remains after initial assessment. (More info – 2017 Comprehensive Update of the Canadian Cardiovascular Society Guidelines for the Management of Heart Failure)
- Caveat is that NP levels are useful to monitor ongoing management and have prognostic value.
- BNP <100 nanograms/L or NT-proBNP <300 nanograms/L strong negative predictors of heart failure.
- BNP >400 nanograms/L or NT-proBNP >900 (>1800 if age 75+) nanograms/L make heart failure more likely.
- Adjustments:
- GFR <60mL/min – halve the BNP or NT-proBNP value measured.
- BMI >35 – double the BNP or NT-proBNP value measured.
- ECG:
Quality Of Evidence?
High
We are highly confident that the true effect lies close to that of the estimate of the effect. There is a wide range of studies included in the analyses with no major limitations, there is little variation between studies, and the summary estimate has a narrow confidence interval.
Moderate
We consider that the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. There are only a few studies and some have limitations but not major flaws, there are some variations between studies, or the confidence interval of the summary estimate is wide.
Low
When the true effect may be substantially different from the estimate of the effect. The studies have major flaws, there is important variations between studies, of the confidence interval of the summary estimate is very wide.
Justification
While heart failure can be a difficult diagnosis there is overall agreement between sources on the necessary steps and investigations.
Related Information
Reference List
Relevant Resources
RELEVANT RESEARCH IN BC
Cardiovascular EmergenciesRESOURCE AUTHOR(S)
DISCLAIMER
The purpose of this document is to provide health care professionals with key facts and recommendations for the diagnosis and treatment of patients in the emergency department. This summary was produced by Emergency Care BC (formerly the BC Emergency Medicine Network) and uses the best available knowledge at the time of publication. However, healthcare professionals should continue to use their own judgment and take into consideration context, resources and other relevant factors. Emergency Care BC is not liable for any damages, claims, liabilities, costs or obligations arising from the use of this document including loss or damages arising from any claims made by a third party. Emergency Care BC also assumes no responsibility or liability for changes made to this document without its consent.
Last Updated Aug 07, 2020
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