Congestive Heart Failure (CHF) is a disorder of the pumping or filling ability of the heart. The most common cause is coronary artery disease and chronic hypertension. It commonly presents with symptoms suggesting volume overload.
According to the American Heart Association (AHA), heart failure is defined as a constellation of signs and symptoms caused by structural or functional impairment of ventricular filling and/or ejection of blood, leading to the cardinal symptoms (dyspnea and fatigue), and signs (edema and rales) of heart failure.
Definition of terms
| Term | Definition |
|---|---|
| Congestive Heart Failure (CHF) | A clinical syndrome in which the heart is unable to pump enough blood to meet the metabolic needs of the body |
| Heart Failure with Reduced Ejection Fraction (HFrEF) | Formerly systolic Heart failure. CHF with reduced stroke volume, reduced ejection fraction (Left Ventricular Ejection Fraction ≤ 35-40%) |
| Heart Failure with Preserved Ejection Fraction (HFpEF) | Formerly, diastolic Heart failure. CHF with reduced stroke volume, normal or reduced end-diastolic volume, and preserved ejection fraction (Left Ventricular Ejection Fraction 50-70%) |
| Borderline HFpEF | has a Left Ventricular Ejection Fraction of 40-49% |
| Right Heart Failure (RHF) | CHF due to right ventricular dysfunction resulting in congestion of blood in the vena cava and peripheral veins, which increases venous hydrostatic pressure and results in peripheral edema, increased jugular venous pressure, ascites, and hepatomegaly |
| Left Heart Failure (LHF) | CHF due to ventricular dysfunction resulting in tissue hypoperfusion and increased pulmonary capillary pressure. |
| Biventricular or Global heart failure | CHF in which both the left and right ventricles are affected, resulting in the development of both RHF and LHF symptoms |
| Chronic compensated heart failure | CHF on echocardiography, but the patient is asymptomatic or symptomatic and stable |
| Acute decompensated heart failure | Sudden deterioration of CHF or new onset of CHF due to an acute cardiac condition such as myocardial infarction |
Framingham’s diagnostic criteria for heart failure
| Category | Criteria |
|---|---|
| Major criteria | Acute pulmonary oedema, cardiomegaly, hepatojugular reflux, neck vein distension, PND or orthopnea, rales, third heart sound gallop |
| Minor criteria | Ankle edema, dyspnea on exertion, hepatomegaly, nocturnal cough, pleural effusion, tachycardia (>120) |
NYHA Heart Failure Classification – based on the patient’s functional capacity. It has prognostic value.
| NYHA Class | Limitation to physical activity | Signs and symptoms |
|---|---|---|
| Class I | No limitation of physical activity | Ordinary physical activity does not cause symptoms |
| Class II | Slight limitation of physical activity | Comfortable at rest. Ordinary physical activity causes symptoms |
| Class III | Marked limitation of physical activity | Comfortable at rest. Less than ordinary activity causes symptoms |
| Class IV | Severe limitation of physical activity | Symptoms are present even at rest |
| HFrEF | HFpEF | |
|---|---|---|
| Pathophysiology | Impaired contractility; Dilated Heart | Impaired relaxation and filling; Hypertrophic heart |
| Ejection fraction | Reduced | Normal/Preserved |
| Symptoms | Similar presentation | Similar presentation |
| Murmur | S3 | S4 |
| Patient | Coronary artery disease, Prior myocardial infarction | Long-standing hypertension, Varied history |
| Investigations | CXR, EKG, Echo | CXR, EKG, Echo |
| Echocardiography | EF <40%, Cardiomegaly | Preserved EF |
| Management | Rate control (BB); Afterload reduction (ACEi) +/- Diuretic. Treat the underlying cause | Control hypertension; Judicious use of diuretics in exacerbation. Treat the underlying cause |
- Causes of heart failure
- HFrEF
- Coronary artery disease
- Hypertension
- Dilated Cardiomyopathy
- Obstructive valvular disease – aortic stenosis
- Regurgitant valvular disease – mitral regurgitation
- Cor pulmonale
- Chronic bradyarrhythmia
- Chronic tachyarrhythmias
- HFpEF >40-50%
- Hypertrophic cardiomyopathy (hypertensive heart disease)
- Restrictive cardiomyopathy
- High-output states
- Hyperthyroidism
- Beriberi
- Arteriovenous shunting
- Chronic anemia
- HFrEF
- Pathophysiology
- Underlying mechanisms
- HFrEF: reduced contractility → ↓ LVEF → ↓ cardiac output
- HFpEF: ↓ compliance → impaired filling + ↑ diastolic pressure → ↓ cardiac output (normal LVEF)
- Left-sided HF: ↑ afterload (hypertension, aortic stenosis); ↑ preload (aortic regurgitation)
- Right-sided HF: ↑ afterload (pulmonary hypertension); ↑ preload (tricuspid regurgitation, left-to-right shunts)
- Compensatory mechanisms
- Structural changes: hypertrophy and dilation (volume overload → chamber dilation; pressure overload → wall thickening)
- Neurohumoral: RAAS (↑ TPR, ↑ fluid retention); sympathetic activation (↑ HR, ↑ contractility, ↑ venous return); ANP (↑ natriuresis)
- Frank-Starling: ↑ preload → ↑ stretch → transient ↑ stroke volume
- Effects of compensation
- Adrenergic desensitization → ↓ catecholamine response
- Myocyte loss → due to chronic stress
- Worsened congestion → fluid overload
- ↓ Cardiac output → due to ↑ afterload
- Adverse remodeling → angiotensin II & aldosterone effects
- Underlying mechanisms
- Signs and symptoms
- Shortness of Breath
- Dyspnea
- Easy fatiguability
- Peripheral oedema
- Orthopnea
- Differentials
- Deconditioning – the patient may be out of shape, which happens with age
- Isolated valvular lesions
- Primary lung disease, e.g., COPD
- Renal disease, e.g., nephrotic syndrome