Acute Heart Failure


  • Acute Heart Failure (AHF) is worsening or decompensation of the signs and symptoms of heart failure
  • Initial evaluation should focus on confirming diagnosis and precipitating causes
  • Treatment includes supportive measures (i.e. oxygenation and blood pressure), loop diuretics for volume overload, and escalating advanced therapies if required
  • Once out of the acute phase, guideline-directed medical therapy should be initiated (discussed in the Chronic Heart Failure topic)


CCS Diagnosis Algorithm

CCS Diagnosis of heart failure in the acute care setting.

Risk Factors

Adapted from CCS 2017 Heart Failure Guidelines
Demographic Medical History Markers
Older age Hypertension Abnormal ECG
Male CAD Widened cardiac silhouette on CXR
Heavy alcohol use Diabetes Elevated neurohormonal biomarkers
Smoking Hyperlipidemia Elevated resting heart rate
Physical inactivity Obesity Microalbuminuria


  • Progressive shortness of breath (LR+ 1.3)
  • Orthopnea (LR+ 2.2)
  • Paroxysmal Noctural Dsypnea (LR+ 2.6)
  • Ankle swelling
  • Abdominal fullness
  • Weight gain (LR+ 1.0)
  • Nausea and/or anorexia (hepatic congestion)
  • Fatigue/lethargy (LR+ 1.0)


  • Elevated JVP (LR+ 5.1)
  • Positive hepatojugular reflux (10s pressure, 3cm rise) (LR+ 6.4)
  • Crackles (LR+ 2.8)
  • Decreased air entry to bases (pleural effusion)
  • S3 (LR+ 11)
  • Laterally displaced apex beat

Note: JAMA – “Does This Dyspneic Patient in the Emergency Department Have Congestive Heart Failure?” Full article here

Search for a Precipitant

CCS 2017 Heart Failure Guidelines
  • If trigger not identified, patient may have refractory HF or recurrent admissions

Diagnostic Algorthm


  • Labs: CBC, Lytes, Creatinine, Urea, Glucose
    • BNP (use to increase/decrease pretest probability, follow treatment, and as a prognostic marker)
    • Troponin (use to assess for ischemia, and to prognosticate – persistently elevated Tn is a marker of poor prognosis)
  • Imaging:
    • CXR (cardiac size, congestion, and other pulmonary processes)
    • ECG (arrhythmia, ischemia, and structural abnormalities)
    • Transthoracic echo*
  • Any other investigations required to workup precipitant and cause of heart failure

*Perform within 72 hours of admission. If previous echo < 12 months ago, no significant change in clinical status, and responding to therapy do not need to repeat.


CCS Treatment Algorithm

CCS Treatment algorithm for acute heart failure.

Supportive Care

  • Supplemental oxygen
    • Indicated for patients who are hypoxemic, target oxygen saturation above 90%
    • Potential harm of oxygen on normoxic patients in physiologic studies
    • Indications:
      • High respiratory rate (concern for fatigue)
      • Persistent hypoxemia despite high flow oxygen
    • Note: Noninvasive ventilation is not recommended for routine use in acute heart failure (3CPO Trial)
  • Diet:
    • Cardiac diet with salt (<2g/day) and fluid (<2L/day) restriction
  • Other:
    • Urinary catheter should be considered but not needed in clinically stable patients
    • Central line and/or arterial line should be considered in hemodynamically unstable patients and those that require inotropes/vasopressors
    • Pulmonary artery catheter should not be routinely used but may be helpful in complex patients used in consultation with Cardiology/Heart Failure Service

Diuretic Therapy

  • IV Diuretics:
    • First line therapy for patients with volume overload (pulmonary or peripheral)
    • IV intermittent dosing recommended over IV continuous as no proven benefit of IV continuous but limits patient mobility
    • IV high dose (oral dose = IV dose x 2.5, ie. 40 mg PO = 100 mg IV) or low dose (oral dose = IV dose, ie. 40 mg PO = 40 mg IV) are reasonable options with high dose shown to have faster symptom resolution without a significant difference in renal function (DOSE trial)
Diuretic Dosing Guide Adapted from CCS 2017 Heart Failure Guidelines
eGFR Patient Initial IV Dose
≥60mL/min/1.73 m2 New onset HF or no current diuretic therapy Furosemide 20-40 mg 2-3 times daily
Established HF or chronic oral diuretic therapy Furosemide dose IV equivalent of oral dose
<60mL/min/1.73 m2 New onset HF or no current diuretic therapy Furosemide 20-80 mg 2-3 times daily
Established HF or chronic oral diuretic therapy Furosemide dose IV equivalent of oral dose

Other Medical Therapy

  • IV Vasodilators:
    • Indication: Relief of dyspnea in hemodynamically stable patients (SBP >100 mmHg)
    • Options: Nitroglycerin, nesiritide, or nitroprusside; and if not available, nitro patch or oral ISDN can be used
    • Note: No evidence for reduction of hospitalization or mortality thus should be used for symptom control
  • IV Inotropes:
    • Not recommended for routine use for hemodynamically stable patients (i.e. milrinone, dobutamine, dopamine, or levosimendan).
    • May be used to stabilize patients with low SBP (<90 mmHg), low cardiac output and either euvolemia or hypervolemia (further discussed in pending Cardiogenic Shock topic)
    • Continue if chronic therapy and stable kidney function but do not start new in acute setting (first 8-12 hours)
  • Beta Blockers:
    • Continue use unless symptomatic hypotension or bradycardia (consider dose reduction first then discontinuation)
    • Wait to start new until out of of acute setting and out of heart failure

Monitoring and Discharge

CCS Ongoing Therapy and Monitoring Algorithm

Stepped pharmacologic care

Monitoring and Targets

  • Monitor patient fluid intake/output and weight
  • Target net in/ outs of -1L and weight loss of 1kg
  • If not achieving target, increase diuretic dose by 50%
  • Practical Tip: If not achieving target at high dose IV lasix (160-240 mg total per day), consider adding metolazone, changing to IV continuous dosing and/or adding inotropic support in conjunction with Nephrology or Cardiology consultation


  • Once euvolemic, transition to lowest dose of oral diuretic to maintain euvolemia
  • Monitor patient for 24 hours after transition from IV to oral diuretic
  • Note: Oral furosemide has 50% bioavailability of IV furosemide (Ie. 40mg IV approximates 80mg PO)
  • Patients should be started on guideline-directed medical therapy before discharge (i.e. Beta blocker, ACE/ARB/ARNI, MRA)
    • See pending Chronic Heart Failure topic for more information
Readiness for Discharge Adapted from CCS 2017 Heart Failure Guidelines
Symptoms and disease Stability Transition
Intercurrent cardiac illness adequately diagnosed and treated Returned to “dry” weight and stable for > 24 hours Communication to primary care provider and/or specialist physician and/or multidisciplinary disease management program
Presenting symptoms resolved Vital signs resolved and stable for > 24 hours, especially blood pressure and heart rate Clear discharge plan for laboratory tests, follow-up, and other testing
Chronic oral HF therapy initiated, titrated, and optimized (or plan for same) > 30% decrease in natriuretic peptide level from time of admission and relatively free from congestion Education initiated, understood by patient, continued education planned

Test Your Knowledge

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Further Reading

  • 2017 CCS: Management of Heart Failure (html) (pdf) (pocketcard)
  • 2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure (html) (pdf)
  • 2016 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure (html)


  • Primary Author: Dr. Atul Jaidka (MD, FRCPC, Cardiology Fellow)
  • Staff Reviewer: Dr. Robert McKelvie (MD, FRCPC[Cardiology])
  • Copy Editor: Perri Deacon (medical student) 
  • Last Updated: March 28, 2020
  • Comments or questions please email