Features of Left Ventricular Failure
Left ventricular failure presents with dyspnea and fatigue limiting exercise tolerance, plus fluid retention causing pulmonary and peripheral edema, driven by decreased cardiac output and elevated left-sided filling pressures. 1
Pathophysiology
Primary Mechanisms
Coronary artery disease causes approximately two-thirds of left ventricular systolic dysfunction cases, with the remaining one-third from nonischemic causes including hypertension, valvular disease, myocardial toxins, myocarditis, or idiopathic dilated cardiomyopathy. 1
The disease creates a self-perpetuating vicious cycle: 1
- Decreased cardiac output → impaired tissue oxygen delivery
- Neurohormonal activation → systemic venous congestion
- Systemic venous congestion → decreased venous return and systemic interstitial fluid accumulation
- Simultaneously increased left-sided filling pressures → pulmonary fluid accumulation
Ventricular Remodeling
The principal manifestation of disease progression is ventricular remodeling, representing homeostatic attempts to decrease wall stress through increases in wall thickness. 1 This results in geometric changes where the left ventricle dilates, hypertrophies, and becomes more spherical rather than maintaining its normal elliptical shape. 1
Clinical Features
Cardinal Symptoms
- Dyspnea (shortness of breath) 2
- Fatigue limiting exercise tolerance 1
- Fluid retention leading to edema 2
Specific Clinical Manifestations
- Pulmonary edema 1
- Peripheral edema 1
- Rales on lung examination 3
- Paroxysmal nocturnal dyspnea 3
- Orthopnea 3
- Jugular venous distention 3
- Presence of third heart sound (S3) 3
Critical Clinical Discordance
A poorly understood discordance exists between ejection fraction severity and functional impairment—patients with very low ejection fractions may be asymptomatic while those with preserved systolic function may have severe disability. 1 This highlights that LVEF alone does not determine symptom severity.
Classification by LVEF
Current Categories 2
- HFrEF (Heart Failure with Reduced EF): LVEF <40%
- HFmrEF (Heart Failure with Mildly Reduced EF): LVEF 41-49%
- HFpEF (Heart Failure with Preserved EF): LVEF ≥50%
HFpEF-Specific Features
Heart failure with preserved LVEF is most prevalent among elderly women, most of whom have hypertension, diabetes mellitus, or both, and often coronary artery disease or atrial fibrillation. 2 Aging has a greater impact on ventricular filling characteristics than on EF. 2
Structural findings in HFpEF include: 2
- Left ventricular hypertrophy
- Atrial dilation
- Mitral annular calcification
- Aortic sclerosis
- Myocardial scar
Initial Assessment
Physical Examination Findings 2
Assess volume status, orthostatic blood pressure changes, weight, height, and calculate body mass index at initial presentation.
Laboratory Evaluation 2
Initial laboratory workup must include:
- Complete blood count
- Urinalysis
- Serum electrolytes (including calcium and magnesium)
- Blood urea nitrogen
- Serum creatinine
- Fasting blood glucose (glycohemoglobin)
- Lipid profile
- Liver function tests
- Thyroid-stimulating hormone
Diagnostic Studies 2
Twelve-lead electrocardiogram and chest radiograph (PA and lateral) are mandatory in all patients presenting with heart failure.
Two-dimensional echocardiography with Doppler must be performed during initial evaluation to assess LVEF, LV size, wall thickness, and valve function. 2
Management Principles
Stage C (Symptomatic) Heart Failure with Reduced LVEF
Core pharmacologic therapy includes: 2
Diuretics and salt restriction for patients with evidence of fluid retention 2
ACE inhibitors for all patients unless contraindicated (Level of Evidence: A) 2
Beta-blockers (bisoprolol, carvedilol, or sustained-release metoprolol succinate) for all stable patients unless contraindicated (Level of Evidence: A) 2
Aldosterone antagonists (spironolactone) in selected patients with moderately severe to severe symptoms who can be carefully monitored—creatinine should be ≤2.5 mg/dL in men or ≤2.0 mg/dL in women, and potassium should be <5.0 mEq/L (Level of Evidence: B) 2, 4
Angiotensin II receptor blockers for patients who are ACE inhibitor-intolerant (Level of Evidence: A) 2
Hydralazine and nitrates combination for African-Americans with moderate-severe symptoms on optimal therapy with ACE inhibitors, beta-blockers, and diuretics (Level of Evidence: B) 2
Critical Medication Avoidance
Drugs that adversely affect clinical status must be avoided or withdrawn: 2
- Nonsteroidal anti-inflammatory drugs
- Most antiarrhythmic drugs
- Most calcium channel blocking drugs
Device Therapy
Implantable cardioverter-defibrillator (ICD) is recommended for: 2
- Secondary prevention in patients with history of cardiac arrest, ventricular fibrillation, or hemodynamically destabilizing ventricular tachycardia (Level of Evidence: A)
- Primary prevention in patients with LVEF ≤35% and NYHA class II or III symptoms on optimal medical therapy (Level of Evidence: A)
Cardiac resynchronization therapy (CRT) with or without ICD should be given to patients with: 2
- LVEF ≤35%
- Sinus rhythm
- NYHA class III or ambulatory class IV symptoms despite optimal medical therapy
- QRS duration ≥0.12 seconds (Level of Evidence: A)
Non-Pharmacologic Interventions
Exercise training is beneficial as an adjunctive approach to improve clinical status in ambulatory patients with current or prior symptoms of heart failure and reduced LVEF (Level of Evidence: B). 2
Progressive Nature and Prognosis
Left-sided heart failure is a progressive disease with established risk factors, asymptomatic phases, and symptomatic phases—analogous to the oncology model of disease progression. 1 The disease can be characterized by four stages of evolution, recognizing that treatments at each stage can reduce morbidity and mortality. 1
The occurrence of organ dysfunction during acute decompensation is associated with poor outcomes and requires aggressive management. 1
The morbidity and mortality associated with heart failure and relatively preserved LVEF may be nearly as profound as that with low LVEF, with frequent and repeated hospitalizations characterizing both groups. 2