Acute heart failure

See also Chronic heart failure for non-critical care management

Background

Etiologies

• Acute coronary syndrome
• Mechanical complications of myocardial infarction
• Acute valvular regurgitation
• Hypertension
• Arrhythmia including atrial fibrillation
• Peripartum cardiomyopathy
• Complications of cardiac surgery
• Infection: myocarditis, infective endocarditis
• Endocrinopathy
• High-output heart failure: sepsis or severe infection, thyroid storm, anemia, arteriovenouss fistula, Paget disease
• Medication non-adherence

Stages

1. Increased filling pressures (i.e. pulmonary artery wedge pressure)
2. Decreased stroke volume and increased heart rate, maintaining cardiac output
3. Further increase in filling pressure and decreased cardiac output (decompensation)

Clinical Manifestations

• Hypoperfusion, with fatigue, weakness, confusion, and pale, cool, and moist extremities
• Circulatory congestion
  • RV failure: peripheral edema, JV distension, epigastric tenderness from hepatomegaly, pleural or pericardial effusions
  • LV failure: pulmonary edema with dyspnea, tachypnea, orthopnea, and crackles on auscultation
• Common symptoms include progressive exertional dyspnea, orthopnea, and paroxysmal nocturnal dyspnea

	Normal Perfusion	Hypoperfusion
Pulmonary congestion	warm and wet	cold and wet
No pulmonary congestion	warm and dry	cold and dry

Rational Clinical Examination

Sign or Symptom	LR+	LR–
CXR showing congestion	12
S3 on auscultation	11
History of heart failure	5.8	0.45
Atrial fibrillation	3.8
Paroxysmal nocturnal dyspnea	2.6
No dyspnea on exertion		0.48
No cardiomegaly on CXR		0.33
Low or normal BNP		0.11

Investigations

• ECG to assess for myocardial infarction, arrhythmia, and conduction abnormalities
• Chest x-ray for evidence of pulmonary congestion, pleural effusion, or cardiomegaly
• Echocardiography
• Laboratory tests
  • Routine, including CBC, creatinine, electrolytes, liver enzymes, ± ABG
  • Cardiac-specific, including troponin and BNP/NT-proBNP

Management

• Treat underlying condition and acute precipitant
• Continue home β-blocker and ACEi/ARB unless hypotensive or bradycardic
• Left-sided heart failure with reduced ejection fraction
  • Managed primarily with vasodilators, loop diuretics, and mechanical ventilation
  • High BP
    • Vasodilators with nitroglycerine, nitroprusside, or nesiritide
    • Diuretic therapy with furosemide for volume overload
  • Normal BP
    • Vasodilator therapy if tolerated (avoid if SBP less than 110 mmHg)
    • Alternately, inodilator therapy with dobutamine, milrinone, or levosimendan
    • Diuretic therapy with furosemide for volume overload
  • Low BP
    • Inodilator therapy with dobutamine
    • Alternately, vasoconstrictor therapy with dopamine
    • Mechanical cardiac support
  • Start ACEi 24-48h into admission, if BP and renal function allow, followed by β-blocker (if tolerated)
• Left-sided heart failure with preserved ejection fraction
  • Control blood pressure (most common cause is hypertension)
  • ACEi/ARB, especially candesartan
  • Consider aldosterone antagonist (e.g. spirolonactone)
  • Monitor and maintain volume status
• Isolated right-sided heart failure
  • Avoid vasodilators (including ACEi/ARBs) and diuretics
  • May need careful fluid administration to improve cardiac output
  • Occasionally need dopamine

Vasodilators

• Nitroglycerin 10 to 20 mcg/min IV, increased by 5 to 10 mcg/min every 3 to 5 minutes as tolerated by SBP
  • Maximum 200 mcg/min
  • Alternatively, can be given translingually 400 mcg every 5 to 10 minutes (usually the dose of 1 spray)
  • Alternatively, can be given as transdermal patch 0.4-0.8 mg/h
  • Used for short period of time because tolerance develops within 24 to 48 hours
• Sodium nitroprusside 0.3 mcg/kg/min IV, increased up to maximum of 5 mcg/kg/min
  • Preferred in hypertension or mitral regurgitation
  • Avoid in acute coronary syndrome (may cause coronary steal effect)
  • Can cause cyanide toxicity
• Avoid starting new ACEi/ARB in the acute setting, but they should be started before discharge if no contraindication

Diuretic Therapy

• Furosemide
  • Moderate volume overload: 20 to 40 mg daily PO or IV
  • Severe volume overload: 40 to 100 mg IV, or continuous infusion of 5 to 40 mg/h
• If inadequate response, can add hydrochlorothiazide 50 to 100 mg PO daily or spironolactone 25 to 50 mg daily
  • Or metolazone
• If inadequate response, consider dobutamine, dopamine, or dialysis
• Once stable, consider aldosterone antagonist (e.g. spironolactone) if LVEF ≤40% and no contraindications

β-Blockers

• Continue home β-blockers if no contraindications (e.g. hypotension or bradycardia)
• If no home β-blockers, add once stable

Supportive Treatment

• Position the patient upright, ideally with legs over bed to aid venous pooling and decrease preload
• Supplemental oxygen by nasal prongs or face mask
• Consider noninvasive positive-pressure ventilation in patients with SpO2 <90% despite supplemental oxygen
  • CPAP preferred
• Salt and fluid restriction
• Daily weights: target 1kg (0.5-1.5) weight loss with 3L urine output daily
• Hydromorphone or morphine for pain and dyspnea

Discharge

• Reinforce education
  • Low-salt diet
  • Daily weights, and logging
  • Alert CHF clinic if dizzy or gained/lost 3lbs
• Document discharge weight and discharge BNP
• Ensure β-blocker and ACEi/ARB are started, if appropriate
• See also Chronic heart failure