Cardiology > Heart Failure (HF)

Background 

Heart failure (HF) is a clinical syndrome characterized by the heart’s inability to pump sufficient blood to meet the metabolic demands of the body. It results from structural or functional cardiac disorders impairing ventricular filling or ejection of blood. 

Classification 

Heart failure is classified based on several factors: 

A) Based on Ejection Fraction (EF): 

• • HFrEF (Heart Failure with reduced EF): EF < 40% 

• • HFpEF (Heart Failure with preserved EF): EF ≥ 50% 

• • HFmrEF (mildly reduced EF): EF 41–49% 

HFrEF is also known as systolic dysfunction.  

HFpEF is similarly referred to as diastolic dysfunction. 

B) Based on Anatomy: Left-Sided vs Right-Sided Heart Failure 

I ) Left-Sided Heart Failure (LHF) 

• Inability of the left ventricle to pump blood effectively to the systemic circulation. 

Causes:                                                          

• • Ischemic heart disease (MI, CAD)             

• • Hypertension                                                              

• • Aortic stenosis                                                      

• • Mitral regurgitation                                             

• • Dilated or hypertrophic cardiomyopathy                                                                                 

II) Right-Sided Heart Failure (RHF) 

Inability of the right ventricle to pump blood effectively into the pulmonary  circulation. 

Causes:                                                                             

• • Left-sided heart failure (most common)        

• • Pulmonary hypertension                                      

• • COPD → cor pulmonale                                       

• • Pulmonary embolism                                             

• • Tricuspid or pulmonary valve disease          

• • Right ventricular infarct (RMI)                          

III) Congestive Heart Failure (CHF) 

• • Is a term used when both sides are failing 

• • • Often starts as LHF → leads to RHF due to pulmonary pressure overload 

• • Presents with combined pulmonary and systemic congestion 

C) Based on Timing of Onset: 

• • Acute vs. Chronic: Acute HF presents suddenly, while chronic HF develops over time with periods of stability and exacerbation.  

• Acute Decompensated Heart Failure (ADHF) 

• • Acute Decompensated Heart Failure is a sudden or gradual worsening of heart failure symptoms, usually in a patient with pre-existing chronic HF. It is a medical emergency and a leading cause of hospitalization in older adults. 

• • ADHF = acute worsening of cardiac function → volume overload, poor perfusion, or both 
    May present as: 

              Worsening of chronic HF (most common) 

              New-onset (“de novo”) heart failure (e.g., from MI or

              hypertensive crisis)

D) High-Output Heart Failure 

High-output heart failure is a less common form of heart failure where cardiac output is elevated, but still inadequate to meet the body’s metabolic demands. Unlike typical low-output heart failure, the problem isn’t weak pumping — it’s the body’s excessive demand or abnormally low systemic vascular resistance. 

High-output heart failure occurs when the heart is pumping more than normal (> 8 L/min), yet the tissues remain hypoperfused due to: 

• Low systemic vascular resistance, or 

• Increased metabolic demand 

The heart itself may be structurally normal or even hyperdynamic initially, but sustained overwork leads to eventual cardiac dysfunction. 

Etiology

A) Causes of HFrEF (EF <40%) 

Primary mechanism:  

• Impaired contractility/systolic dysfunction 

I) Ischemic causes (most common) 

• • Myocardial infarction (MI) 

• • Chronic coronary artery disease (CAD) 

• • Hibernating myocardium 

II) Non-ischemic cardiomyopathies 

• • Dilated cardiomyopathy (idiopathic, familial/genetic) 

• • Toxic: Alcohol, cocaine, chemotherapy (e.g., doxorubicin, trastuzumab) 

• • Infectious: Viral myocarditis (e.g., Coxsackievirus, adenovirus) 

• • Peripartum cardiomyopathy 

• • Tachycardia-induced cardiomyopathy (e.g., from AF with RVR) 

III) Pressure/volume overload 

• • Chronic hypertension 

• • Aortic or mitral regurgitation 

• • Severe aortic stenosis (late stages) 

IV) Metabolic and systemic 

• • Thyroid dysfunction (especially hyperthyroidism) 

• • Nutritional (thiamine deficiency — wet beriberi) 

• • Iron overload (hemochromatosis) 

V) Infiltrative/autoimmune 

• • Sarcoidosis 

• • Systemic lupus erythematosus (rare) 

B) Causes of HFpEF (EF ≥50%) 

Primary mechanism:  

Impaired relaxation/diastolic dysfunction + ventricular stiffness 

I) Common comorbid conditions 

• • Chronic hypertension (leads to LV hypertrophy) 

• • Aging (decreased compliance) 

• • Obesity (increased cardiac workload) 

• • Diabetes mellitus 

• • Coronary artery disease (ischemia without infarction) 

II) Cardiomyopathies 

• • Hypertrophic cardiomyopathy 

• • Restrictive cardiomyopathy: 

• • Amyloidosis 

• • Hemochromatosis (early stage) 

• • Sarcoidosis 

III) Valvular disease 

• • Aortic stenosis (early stages) 

• • Mitral stenosis 

IV) Other 

• • Atrial fibrillation (impairs LV filling) 

• • High-output states (e.g., anemia, thyrotoxicosis — in vulnerable patients) 

• • Constrictive pericarditis 

Right-Sided vs. Left-Sided Heart Failure

Triggers/Precipitating Causes of ADHF (“FAILURES”): 

  Common Causes of Right HF (Mnemonic: AV FISTULA) 

HF Risk Factors: 

• • Diabetes mellitus 

• • Smoking 

• • Obesity 

• • Chronic kidney disease 

• • Sleep apnea 

• • Advanced age 

• • Excessive alcohol use 

• • Family history of cardiomyopathy 

Clinical Presentation 

History (Symptoms) 

• • Exertional dyspnea and/or dyspnea at rest 

• • Orthopnea 

• • Acute pulmonary edema (PND, frothy sputum, wheezing) 

• • Chest pain/pressure and palpitations 

• • Fatigue and weakness 

• • Nocturia and oliguria 

• • Anorexia, weight loss, nausea 

Physical Exam (Signs) 

Vital Signs: 

• • Blood Pressure: Hypotension in advanced HF 

• • Pulse: Tachycardia due to sympathetic stimulation 

        – Weak, rapid, and thready pulse 

• • Respiratory Rate: Tachypnea from pulmonary edema 

• • O2 sat: Hypoxia in decompensated states 

Cardiovascular: 

• • S3 gallop: Sign of volume overload and systolic dysfunction 

• • Displaced apical impulse: Suggests LV hypertrophy or dilation 

• • Jugular venous distention (JVD): Indicates elevated right-sided pressures 

• • Pulsus alternans: Alternating strong and weak pulse in advanced HF 

Respiratory: 

• • Bibasilar crackles or rales: Pulmonary edema 

• • Wheezing (“cardiac asthma”) 

• • Pleural effusions: Often bilateral, right > left 

Abdominal: 

• • Hepatomegaly and hepatojugular reflux: from hepatic congestion 

• • Ascites: Seen in severe right-sided HF 

• • Anasarca (generalized swelling) 

Peripheral Vascular: 

• • Pitting edema in lower extremities 

• • Cool extremities in low output states 

Neurological: 

• • Confusion, dizziness: Hypoperfusion in advanced cases 

Differential Diagnosis 

• • COPD/Asthma exacerbation:  

        Wheezing, no orthopnea or edema 

• • Pneumonia:  

        Fever, consolidation on imaging 

• • Pulmonary embolism:  

        Pleuritic chest pain, sudden onset dyspnea 

• • CKD/Nephrotic syndrome:  

        Edema without dyspnea 

• • Liver cirrhosis:  

        Ascites, but no pulmonary signs 

Diagnosing Heart Failure

Framingham Criteria:  

Requires ≥2 major or 1 major + 2 minor criteria to diagnose heart failure: 

Major: 

• • PND 

• • Neck vein distension 

• • Rales 

• • Cardiomegaly on CXR 

• • Pulmonary edema 

• • S3 gallop 

• • Weight loss ≥4.5 kg with treatment 

Minor: 

• • Peripheral edema 

• • Night cough 

• • Dyspnea on exertion 

• • Hepatomegaly 

• • Pleural effusion 

• • Tachycardia 

• • Nocturnal dyspnea 

Diagnostic Workup: 

Initial Tests: 

I) Echocardiogram (transthoracic):  

• • Is the best initial test to evaluate HF 

• • Most important tool for evaluating EF, chamber size, wall motion, valvular disease 

• • Classify HF as HFrEF or HFpEF 

II) 12-lead ECG:  

• • May show arrhythmias, prior MI, LV hypertrophy 

III) BNP or NT-proBNP:  

• • BNP = B-type natriuretic peptide; NT-proBNP = N-terminal proBNP (BNP precursor) 

• • Elevated in heart failure; helps distinguish from non-cardiac causes of dyspnea especially in atypical presentation 

IV) Chest X-ray:  

• • Cardiomegaly, pulmonary vascular congestion, Kerley B lines, pleural effusions 

Basic Lab Tests 

Other Imaging 

• • Cardiac MRI: For infiltrative or inflammatory cardiomyopathies 

• • Nuclear stress testing or coronary angiography: To assess for ischemic etiology 

Management of Heart Failure 

I) Acute Decompensated HF (ADHF) 

Initial Treatment (“LMNOP”): 

II) Chronic HF Management (Mortality-Reducing Medications) 

Contraindications to Beta-Blockers: 

• • Acute decompensated HF 

• • Bradycardia or heart block 

• • Severe asthma/COPD exacerbation 

• • Cardiogenic shock 

Device Therapy 

I) Implantable Cardioverter Defibrillator (ICD):  

• • • EF <35%, NYHA II–III despite optimal medical therapy 

• • An ICD (Implantable Cardioverter Defibrillator) is a device implanted in patients at high risk of sudden cardiac death (SCD) due to life-threatening ventricular arrhythmias, particularly in heart failure with reduced ejection fraction (HFrEF) 

• • Monitors heart rhythm continuously 

Delivers: 

• • Pacing for bradycardia or minor arrhythmias 

• • Anti-tachycardia pacing (ATP) or 

• • Defibrillation shocks to terminate ventricular tachycardia/fibrillation 

II) Cardiac Resynchronization Therapy (CRT):  

• • • EF <35%, wide QRS (>150 ms), LBBB morphology 

• • • Is a specialized pacing therapy used in heart failure with reduced ejection fraction (HFrEF) to improve ventricular synchrony, especially in patients with conduction delays (most commonly left bundle branch block – LBBB). 

• • • Resynchronizes contraction of the left and right ventricles 

• • • Improves: 

• • • LV systolic function 

• • • Cardiac output 

• • • Symptoms and exercise tolerance 

• • • Quality of life 

• • • Reduces hospitalization and mortality 

The New York Heart Association (NYHA) Classification 

Is a functional system that categorizes heart failure (HF) based on the severity of symptoms and limitations to physical activity. It is widely used to assess baseline status, prognosis, and response to treatment. 

Class I:  

• No symptoms with ordinary physical activity. 
• Example: Can climb stairs, walk uphill, or do moderate activity without fatigue or dyspnea. 

Class II: 

• Mild limitation of physical activity. 
• Comfortable at rest, but ordinary activity (e.g., walking up 1 flight of stairs) causes fatigue, dyspnea, or palpitations. 

Class III:  

• Marked limitation of physical activity. 
• Comfortable at rest, but less than ordinary activity (e.g., dressing, walking across the room) causes symptoms. 

Class IV:  

• Unable to carry out any physical activity without discomfort.
• Symptoms occur at rest (e.g., dyspnea, fatigue, palpitations). Any activity worsens discomfort. 

Clinical Relevance 

• • Used for staging, treatment planning, and eligibility for advanced therapies (e.g., ICDs, transplant). 

• • Often correlates with quality of life and hospitalization risk. 

• • Can change over time depending on response to therapy. 

Consults

• • Cardiology: For advanced HF, device evaluation, or unclear etiology 

• • Electrophysiology: For ICD or CRT candidacy 

• • Nephrology: If renal dysfunction limits diuretic use or electrolyte control 

• • Palliative care: For refractory symptoms or advanced disease 

Patient Education 

• • Daily weight monitoring: Report if gain >2–3 lbs in 1 day or >5 lbs in a week 

• • Recognize early signs of decompensation: increased dyspnea, edema, fatigue, orthopnea 

Adhere to: 

• • Low-sodium diet (<2 g/day) 

• • Fluid restriction (<2 L/day if volume overloaded) 

• • Maintain physical activity as tolerated (encourage cardiac rehab if eligible) 

• • Emphasize smoking cessation and limit alcohol intake 

• • Take all medications as prescribed; do not stop beta-blockers or ACEi abruptly 

• • Keep all follow-up appointments for labs, imaging, and clinic visits 

• • Encourage caregivers to be involved in monitoring symptoms and adherence 

Screen for and manage: 

• • Depression or cognitive decline (common in chronic HF) 

• • Sleep apnea (especially in HFpEF or refractory HFrEF) 

• • Iron deficiency (common even without anemia; IV iron improves symptoms) 

• • Thyroid dysfunction (both hypo- and hyperthyroidism can worsen HF) 

• • Diabetes and lipid control (optimize comorbidity management) 

• • Arrhythmias, especially atrial fibrillation or bradyarrhythmias 

• • Frailty or sarcopenia, particularly in elderly HFpEF patients 

Vaccinations before discharge: 

• • Influenza vaccine annually 

• • Pneumococcal vaccines: 

• • PCV20 (or PCV15 + PPSV23 as alternative per CDC guidelines) 

• • COVID-19 vaccination and boosters 

• • Consider Tdap/Td if not up to date 

Follow-Up 

• • Reassess EF after 3–6 months of optimal therapy 

• • Monitor weight, blood pressure, renal function, electrolytes regularly 

• • Educate on fluid (<2 L/day) and sodium (<2 g/day) restrictions 

• • Refer to cardiac rehab if stable 

• • Assess for medication side effects and adherence