Heart Failure: Types, Causes, Symptoms, Diagnosis & Management

Heart failure (HF) is the condition resulting from inability of the heart to fill and/or pump blood sufficiently to meet tissue metabolic needs. It is the final common pathway for a wide variety of cardiac diseases & it is the principal complication of heart disease.

Advances in the diagnosis and treatment of HF 

Causes & Types of heart failure 

Heart failure can be systolic or diastolic, acute or chronic, and left or right side heart failure or both (biventricular failure)

Systolic Heart Failure (SHF) or Heart Failure with reduced Ejection Fraction (HFrEF)

• SHF is the most common type of LHF, is characterized by a low ejection fraction (EF <40%) due to defect in ventricular contraction. Often due to myocardial infarction (MCC) or dilated cardiomyopathy.
• It's affects all ages and more common in males. S3 is usuallypresent. 

Causes of Systolic Heart Failure  

1. Ischemic heart disease or after a recent MI
2. Idiopathic
   
3. HTN
   
4. Myocarditis (postviral, giant cell, autoimmune)
   
5. Drugs: Alcohol, cocaine, methamphetamines, chemotherapy (anthracyclines and trastuzumab)
   
6. Infiltrative disease (amyloidosis, sarcoidosis, hemochromatosis, Wilson disease) 
7. Radiation therapy 
8. Thyroid disease 
9. Peripartum cardiomyopathy
10. Infectious disease (Chagas disease, HIV, endocarditis causing valvular disease)
11. Valvular heart disease (usually MR, aortic stenosis or regurgitation)
12. High-output heart failure (severe anemia, due to AV fistulas, pregnancy, severe thiamine deficiency) 
    
13. Congenital/hereditary  

What is High-output heart failure?

• Almost type of HF have low Cardiac output. In high-output heart failure, an increase in cardiac output is needed for the requirements of peripheral tissues for oxygen.
• Causes include: (Severe anemia, Pregnancy, Hyperthyroidism, AV fistulas, Wet beriberi [thiamine deficiency]). 
• The conditions listed above rarely cause heart failure by themselves. However, if these conditions developin the presence of underlying heart disease, heart failure can result quickly.

Diastolic Heart Failure (DHF) or Heart Failure with preserved Ejection Fraction (HFpEF)

• DHF is characterized by a normal EF (>60%) at rest. Owing to impaired ventricular filling during diastole (either impaired relaxation or increased stiffness of ventricle or both). 
• Often due to HTN which leading to myocardial hypertrophy (LV hypertrophy).
• It's affects elderly patients; occurs more often in females. 
• S4 is present (S3 may be present in patients with significantly elevated left ventricular filling pressures)

Causes of Diastolic Heart Failure

1. HTN leading to myocardial hypertrophy—most common cause of diastolic dysfunction
2. Valvular diseases such as aortic stenosis (AS), mitral stenosis, and aortic regurgitation
   
3. Restrictive cardiomyopathy (e.g., amyloidosis, sarcoidosis, hemochromatosis in their early phases)

Most patients with heart failure have a combination of systolic and diastolic dysfunction of the left ventricle.

Pathophysiology OF Left & Right side heart failure 

Left-sided heart failure (MC): Blood backs up through the left atrium into the pulmonary veins --> Pulmonary congestion and edema

1. Acute H.F: An acute increase in left atrial pressure may cause pulmonary oedema
2. Chronic H.F: A more gradual increase leads to reflex pulmonary vasoconstriction and pulmonary hypertension--> Eventually leads to biventricular failure (CHF)

Right-sided heart failure (RHF): Blood backs up into right atrium and venous circulation --> Venous congestion. The most common cause of right heart failure is left heart failure.

What is  the difference between Congestive Heart Failure (CHF) and Acute decompensated heart failure (ADHF)?

Congestive Heart Failure (CHF)

• The term congestive heart failure (CHF) is used for the chronic form of heart failure in which the patient has evidence of congestion of peripheral circulation and of lungs.
• This may develop because disease affects both ventricles (e.g. dilated cardiomyopathy), because left heart failure leads to chronic elevation of left atrial pressure, pulmonary hypertension and right heart failure. (Biventricular heart failure)

Acute decompensated heart failure (ADHF) 

• ADHF is a rapid-onset cardiac pump function impairment, resulting in inefficient perfusion, yielding symptoms due to excessive fluid accumulation and due to reduction in cardiac output. Most commonly due to LV systolic or diastolic dysfunction.
• ADHF can be a new diagnosis or worsening of preexisting chronic HF.

Signs & Symptoms of Heart Failure 

What is the features of Acute decompensated heart failure?

• In acute setting dyspnea on exertion and orthopnea are the only symptoms with high sensitivity but suffer from low specificity.
• Acute dyspnea associated with elevated left-sided filling pressures, with or without pulmonary edema. 
• Flash pulmonary edema refers to a severe form of heart failure with rapid accumulation of fluid in the lungs.
  

What is Signs & Symptoms of Congestive Heart Failure

Symptoms and signs of CHF divide into Forward & Backward symptoms & signs:

1. Forward symptoms & signs: occur due to decrease C.O.P from left side of heart. 
2. Backward symptoms & signs: occur due to congestion of blood in venous system: Pulmonary venous congestion (P.V.C) in left side heart failure. Systemic venous congestion (S.V.C) in right side heart failure.

Forward symptoms & signs of CHF

1. Brain: Dizziness, confusion, headache, syncope, insomnia. Confusion and memory impairment occur in advanced CHF as a result of inadequate brain perfusion
2. Cardiac: Palpitation, Chest pain in sever decline in C.O.P).
   
3. Respiratory: Cheyne stoke breathing: periodic breathing occur in advanced sever H.F
   
4. Kidney: Day time Oliguria & Nocturia. bed rest act as diuretic in patient with heart failure, because at time of daily activity limited cardiac output shifted from kidney to skeletal muscle lead to decrease blood flow to kidney(oliguria < 30ml/hr.) and at bed rest blood flow shifted from relaxed skeletal muscle to kidney (Nocturia).
5. Skeletal muscle: Fatigue, weakness & intermittent claudication.
   
6. Skin: Pale skin and cold extremity. Cyanosis in acute severe cases.
   
7. Sign: Weak pulse, Tachycardia unless on treatment of (digitalis or b-blockers), Alternating strong & weak beats or pulse (In advanced stage), Low BP, & Capillary refilling time increase.
   

Left sided failure (backward symptoms & signs) include:

1) Dyspnea (earliest feature of LVF): Dyspnea on exertion suggests heart failure; dyspnea at rest suggests pulmonary disease.

2) PND refers to an awakening from sleep after 2 hours with shortness of breath. 

• When classic, indicates left heart failure. MS is the commonest cause for PND. 
• Patients with PND are functionally classified into NYHA class III. 
  
• Once right ventricular failure develops (CHF), PND disappears.

3) Orthopnea: It is dyspnea that occurs in supine position and is promptly relieved by assuming upright position (sitting or standing). 

• Orthopnea is a characteristic of left ventricular failure. the absence of orthopnoea suggests that left ventricular failure is unlikely.
• The orthopnoeic patients often experience paroxysmal nocturnal dyspnoea (PND).
  
• Orthopneic patients are functionally graded to be in NYHA class IV. 
  

4) Exertional Cough: dry cough in interstitial edema, but wet (frothy binky sputum) in pulmonary edema.

5) Rust-colored sputum: Presence of hemosiderin in alveolar macrophages (heart failure cells)

6) Sign: Bibasilar inspiratory crackles (rales), Pathologic S3 (first cardiac sign of LHF)

Right side heart failure (backward symptoms & signs) include: 

1. Dependent pitting edema: Edema in CHF has both a forward (diminished renal perfusion) and backward (increased venous pressure) component.
2. Dyspnea (due to Pleural effusion): The cause of bilateral pleural effusions is almost always CHF.
3. Diaphoresis: due to sympathetic activation.
   
4. Dyspepsia & malabsorption may lead to cardiac cachexia (the wight is elevated due to edema but true wight is decreased).
   
5. Nocturia—due to increased venous return with elevation of legs
   
6. Insomnia: due to cerebral congestion.
   
7. Signs: Cyanosis, Painful hepatomegaly, Prominent JVP, +ve hepatojugular reflux, S3&S4 may hear, hepatojugular reflux (is a manifestation of increased SNS tone).

Cyanosis is more likely to occur in RHF than LHF.

Manifestation Advanced HF 

1. Bradycardia without effect of digitalis or b blockers. 
2. Hypotension.
3.  Pulses alternans. 
4. Cheyne stock breathing. 
   
5. Hyponatremia (delusional hyponatremia due to increase ADH secretion).
   

New York Heart Association Functional Classification (NYHA) of Heart failure 

1) NYHA class I: Ordinary physical activity does not cause symptoms. Symptoms only occur with vigorous activities, such as playing a sport.

2) NYHA class II: slight limitation in ordinary physical activity. Symptoms occur with prolonged or moderate exertion, such as climbing a flight of stairs or carrying heavy packages. These patients are comfortable at rest.

3) NYHA class III: Markedly limitation in ordinary physical activity. Symptoms occur with usual activities of daily living, such as walking across the room or getting dressed. These patients are comfortable at rest (Cardiac transplant indicated).

4) NYHA class IV: Symptoms occur at rest (Need cardiac transplant).

Diagnosis & Treatment 

How HF is diagnosed? 

• Heart failure is a clinical diagnosis, no gold standard; BNP in ADHF is best reserved for situations in which diagnosis of ADHF is unclear.
• β-Type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-BNP) are helpful in the acute setting to differentiate the cause of dyspnea (BNP <100 essentially rules out HF)

Diagnosis criteria of CHF

Diagnosis of CHF requires the presence of at least 2 major criteria or 1 major criterion in conjunction with 2 minor criteria.

Major criteria 

1. Paroxysmal nocturnal dyspnea 
2. Neck vein distention 
3. Rales 
4. Radiographic cardiomegaly. 
5. Acute pulmonary edema 
6. S3 gallop. 
7. Increased central venous pressure (>16 cm H2O at right atrium) 
8. Hepatojugular reflux 
9. Weight loss > 4.5 kg in 5 days in response to treatment.

Minor criteria 

1. Bilateral ankle edema 
2. Nocturnal cough 
3. Dyspnea on ordinary exertion 
4. Hepatomegaly 
5. Pleural effusion 
6. Decrease in vital capacity by one third from maximum recorded 
7. Tachycardia (heart rate> 120 beats/min.)

Right heart failure cannot be diagnosed from symptoms and signs alone. Objective evidence of cardiac dysfunction, for example from echocardiography, is needed

Investigations of patients with Heart failure 

1) Brain natriuretic peptide (BNP) is released from the ventricles in response to ventricular volume expansion and pressure overload.

• BNP levels >100 pg/mL correlate strongly with the presence of decompensated CHF.
• BNP may be useful in differentiating between dyspnea caused by CHF and COPD. 

2) N-terminal pro-BNP (NT-proBNP) is a newer assay with similar predictive value as BNP. The normal range for this value depends on the age of the patient, but an NT-proBNP <300 virtually excludes the diagnosis of HF.

3) Chest x-ray: Signs of pulmonary congestion: Congestion in the upper lobes (early finding), Kerley B line, Air bronchograms, Perihilar congestion (“bat-wing configuration” or “angel-wing configuration”)

4) Echocardiography: 

• Determining whether systolic or diastolic dysfunction predominates
• Determines whether the cause of CHF is due to a myocardial, valvular, or pericardial process.
  
• Shows chamber dilation and/or hypertrophy.
• Estimates EF (very important): Ejection fraction = Stroke volume/ End diastolic volume NB: LVEDD (Left ventricular end-diastolic dimension): 36 - 56 mm

Staging HF according to ejection fraction 

1. GradeI (EF = 60%) but there is structure heart disease.
2. Grade II (40-59%). 
   
3. Grade III (21-39%). 
   
4. Grade IV (= 20%)
   

General Principles in the Treatment of CHF 

No one simple treatment regimen is suitable for all patients. The following is a general guideline, but the order of therapy may differ among patients and/or with physician preferences.

1. Mild CHF (NYHA Classes I to II): Mild restriction of sodium intake (no-added-salt diet of 4-g sodium) and physical activity. Start a loop diuretic if volume overload or pulmonary congestion is present. Use an ACE inhibitor as a first-line agent.
2. Mild to Moderate CHF (NYHA Classes II to III): Start a diuretic (loop diuretic) and an ACE inhibitor. Add a β-blocker if moderate disease (class II or III) is present and the response to standard treatment is suboptimal.
   
3. Moderate to Severe CHF (NYHA Classes III to IV): Can add digoxin (to loop diuretic and ACE inhibitor) for the relief of symptoms in patients with systolic dysfunction. (It does not improve mortality.) Add spironolactone or eplerenone if EF <35%

General measurement For patients with HF 

1. Bed rest (Until signs of HF disappear)
2. Sedation: as diazepam.
   
3. Sodium restriction (less than 4 g/day) 
   
4. Life style modification: Mild exercise, Weight loss, Smoking cessation, Restrict alcohol use
   
5. Vaccine: Annual influenza vaccine and pneumococcal vaccine recommended
   

Long-term medication management for individuals who have CHF

1) ACE inhibitors & ARBs: benefit greatest for patients with systolic dysfunction and postMI. 

2) β-Blockers: used in systolic or diastolic HF. Carvedilol 3.125 mg PO BID to a target of 25 mg PO BID

3) Sacubitril/valsartan (Entresto) is an angiotensin receptor neprilysin inhibitor (ARNI): In patients with systolic HF and NYHA class II and III symptoms who tolerate an ACE-I or ARB, and CrCl >30, replacement by an ARNI is recommended to further reduce morbidity and mortality.

ACE-Is or ARBs should be discontinued at least 36 hours prior to starting ARNIs.

4) Diuretics are helpful to manage volume overload/reduce preload.

• Furosemide (Lasix): 20 to 320 mg/day IV/IM/PO divided dose
• Spironolactone 12.5 to 25.0 mg/day PO; maximum 50 mg/day PO Or eplerenone 25 to 50 mg/day; caution regarding hyperkalemia and chronic kidney disease (CKD) 

5) Digoxin: In patients with preserved renal function (CrCl >50 mL/min), the recommended dose is 0.125 mg/day. 

6) Intravenous iron replacement might improve functional status and quality of life in patients with NYHA II and III HF and iron deficiency (ferritin <100 ng/mL or 100 to 300 ng/mL if transferrin saturation <20%).

7) In diastolic HF, no medical therapy has improved survival. ARBs and spironolactone can be used to potentially reduce hospitalizations

NB: The combination of hydralazine (75 mg/day divided BID or TID) and isosorbide dinitrate (40 mg QID) is effective if pt. unable to take ACE-I or an ARB

Treatment of ADHF

1. Oxygenation and ventilatory assistance with nonrebreather face mask, noninvasive positive pressure ventilation, or even intubation as indicated.
2. Diuretics to treat volume overload and congestive symptoms—this is the most important intervention. Decreases preload.
3. Nitrates—IV nitroglycerin (venodilator) in patients without hypotension. Decreases preload.
4. Patients who have pulmonary edema despite use of oxygen, diuretics, and nitrates may benefit from use of inotropic agents (dobutamine). Digoxin takes several weeks to work and is not indicated in an acute setting.
5. Dietary sodium and fluid restriction.

Emergency medical services in the management of ADHF on CHF patient 

1. IV diuretics are used initially in fluid-overload acute HF, with nitrates added if needed, especially if patient is hypertensive.
2. Using early noninvasive ventilation for the treatment of pulmonary edema can bridge care while awaiting the effects of diuretics and can decrease morbidity and mortality associated with intubation.
3. The addition of ACE-I and aldosterone antagonists can be added at any time.
4. Once acute HF is stabilized, a β-blocker should be started. β-Blockers, ACE-I, and aldosterone antagonists are the core medications for management of chronic HF.
5. Consider referral for biventricular pacing in patients with LBBB and ICD in those with low EF.

NB: Avoid nonsteroidal anti-inflammatory drugs (NSAIDs), which markedly worsen HF. Avoid the use of diltiazem and verapamil in patients with systolic dysfunction as they may increase mortality and have negative inotropic effects.

Medications used to manage ADHF 

1) loop diuretics recommended for all patients with ADHF and symptoms of fluid overload in hemodynamically stable patients (contraindicated if systolic blood pressure [SBP] <90 mm Hg, severe hyponatremia, acidosis) 

• Furosemide (Lasix): New-onset ADHF patients should get boluses of 20 to 40 mg IV
• Metolazone (Zaroxolyn): 2.5 to 20.0 mg/day PO, can be added as second diuretic in cases of ineffective diuresis
  

2) Vasodilators: Consider in ADHF with SBP >90 mm Hg and patients with hypertensive ADHF should get IV vasodilators as initial therapy to reduce congestion. NB: Use in chronic HF is not effective.

• IV nitroglycerin may be of short-term benefit to decrease preload, afterload, and systemic resistance (IV 10 to 20 μg/min, increase up to 200 μg/min).
• IV nitroprusside: Administer with caution, start with 0.3 μg/kg/min and increase up to 5.0 μg/kg/min.
  

3) Tolvaptan (an oral vasopressin antagonist) for severe hypervolemic hyponatremia refractory to water restriction and medical therapy 

• Vasopressors: Consider in patients with cardiogenic shock despite treatment with another inotrope

4) Inotropes: reserved for patients with severe systolic dysfunction occurring most often in hypotensive ADHF.

• Dobutamine infusion 2 to 20 μg/kg/min requires close BP monitoring; avoid in cardiogenic shock or with tachyarrhythmias.
• Low-dose dopamine infusion may be considered (3 to 5 μg/kg/min)
• Norepinephrine 0.2 to 1.0 μg/kg/min compared with dopamine has fewer side effects and lower mortality.
• Epinephrine restricted to patients with persistent hypotension despite other agents.