Identifying the underlying cause of HF is essential — some etiologies are reversible, and treatment differs accordingly. Common causes include:

• Ischemic heart disease: The most common cause of HFrEF in developed countries. All new HF patients should be assessed for CAD (coronary angiography or non-invasive testing as appropriate).
• Hypertension: Chronic pressure overload leads to LVH and eventually diastolic then systolic dysfunction. A major contributor to HFpEF.
• Valvular heart disease: Aortic stenosis, mitral regurgitation — may require surgical or percutaneous intervention.
• Non-ischemic cardiomyopathy: Dilated (idiopathic, familial), hypertrophic, restrictive, peripartum, stress (Takotsubo).
• Toxins: Alcohol (reversible with abstinence), chemotherapy (anthracyclines, trastuzumab), stimulants.
• Tachycardia-mediated cardiomyopathy: Prolonged uncontrolled tachyarrhythmia (e.g., AF with rapid ventricular response). Often reversible with rate/rhythm control.
• Infiltrative: Amyloidosis (cardiac), sarcoidosis, hemochromatosis — consider in unexplained HFpEF or HF with LVH and low voltage on ECG.
• Other: Myocarditis, thyroid disease (hyper- or hypothyroidism), high-output states (anemia, AV fistula), pericardial disease.

Etiologic workup for new HF includes echocardiography (LVEF, wall motion, valves, diastolic function), coronary assessment, and targeted investigations based on clinical suspicion (e.g., cardiac MRI for infiltrative disease, iron studies for hemochromatosis, thyroid function).

Managing diuresis day-to-day on the ward is a core internal medicine skill. Reassess volume status daily and adjust accordingly:

• Daily weights & I/Os: Target net negative 1–2 L/day (or ~0.5–1 kg/day weight loss). Weigh at the same time each morning.
• Reassess the exam daily: JVP, crackles, edema, orthopnea. Use the JAMA Rational Clinical Exam findings — JVP (LR+ 4.1) and S3 (LR+ 11) are the most specific bedside signs of persistent congestion.
• Inadequate response? First, re-consider the diagnosis — is this truly decompensated HF, or could there be another cause (e.g., hepatic cirrhosis, nephrotic syndrome, PE)? If HF is confirmed: consider adding metolazone (2.5–5 mg PO 30 min before furosemide) for sequential nephron blockade, or double the IV furosemide dose. Continuous furosemide infusion (5–20 mg/h) is an option but typically requires CCU/ICU-level monitoring.
• Monitor renal function and electrolytes: Check Cr, K+, Mg2+, and bicarbonate at least daily during active diuresis. Mild rises in Cr (“pseudo-worsening renal function”) are acceptable if decongestion is occurring. A rising bicarbonate (“contraction alkalosis”) can signal over-diuresis or dehydration — reassess volume status and consider slowing the rate of diuresis.
• Transition to PO before discharge: When euvolemic, convert IV to PO furosemide (IV:PO ratio ~1:2). Observe for 24–48h on the oral dose to confirm stability before discharge.

• Hydralazine/ISDN: Add for self-identified Black patients already on optimal GDMT, or as alternative if ACEi/ARB/ARNi not tolerated (e.g., hyperkalemia, renal dysfunction).
• Ivabradine: For patients in sinus rhythm with resting HR >70 bpm despite maximally tolerated beta-blocker.
• Digoxin: For persistent symptoms despite optimal GDMT. Aim trough 0.5–0.9 ng/mL. No mortality benefit — symptom relief and reduced hospitalization only.
• Loop diuretics: For volume management. No mortality benefit — use the lowest effective dose for euvolemia. Not a “pillar” of GDMT.

Transition of Care

• IV iron (ferric carboxymaltose): Recommended for HFrEF with iron deficiency (ferritin <100 µg/L, or 100–299 with TSAT <20%). Improves symptoms, functional capacity, and quality of life (AFFIRM-AHF). Check iron studies on all HF patients.
• In-hospital ARNi initiation: The PIONEER-HF trial showed that starting sacubitril-valsartan in hospital (once hemodynamically stable ≥24h) led to greater NT-proBNP reduction vs. enalapril. Consider initiating ARNi before discharge in eligible patients.

The CCS guidelines emphasize that pharmacotherapy alone is insufficient. Key non-pharmacologic recommendations include:

• Sodium restriction: Limit to <2 g/day. Counsel on reading food labels and avoiding processed foods.
• Exercise: Regular aerobic exercise (e.g., 30 min/day, 5 days/week) is safe and improves functional capacity and quality of life in stable HF patients. Cardiac rehabilitation referral is recommended.
• Daily weight monitoring: Patients should weigh themselves daily and have a plan for weight gain >1.5–2 kg over 2 days (e.g., prn diuretic adjustment, contact clinic).
• Multidisciplinary HF care: HF clinics with nurse-led follow-up, pharmacist medication reviews, and dietitian counselling reduce readmissions and mortality.
• Advance care planning: Discuss goals of care early, especially in patients with advanced HF (NYHA III–IV) or frequent hospitalizations. Include discussions about ICD deactivation if appropriate.
• Remote monitoring: Telemonitoring programs (daily weights, symptoms, vital signs) can facilitate early intervention and reduce hospitalizations.