Congestive Heart Failure and Pulmonary Edema

Author Information and Disclosures

Diagnosis and Differentials

Clinical

History:

• Anxiety

• Dyspnea at rest

• Dyspnea on exertion has been found to be the most sensitive symptom reported, yet the specificity for dyspnea is less than 60%.

• Orthopnea and paroxysmal nocturnal dyspnea (PND) are symptoms; however, sensitivity for orthopnea and PND is only 20-30%.

• Cough productive of pink, frothy sputum is highly suggestive of CHF.
• Edema

• Nonspecific symptoms reported include the following:

• Weakness

• Lightheadedness

• Abdominal pain

• Malaise

• Wheezing

• Nausea

• Past medical history may include the following:

• Cardiomyopathy

• Valvular heart disease

• Alcohol use

• Hypertension

• Angina

• Prior myocardial infarction

• Familial heart disease

Physical:

• Findings such as peripheral edema, jugular venous distention, and tachycardia are highly predictive of CHF. Overall specificity of physical examination has been reported at 90%; however, this same study reported a sensitivity of only 10-30%.

• Tachypnea, using accessory muscles of respiration

• Hypertension

• Pulsus alternans (alternating weak and strong pulse indicative of depressed left ventricle [LV] function)

• Skin may be diaphoretic or cold, gray, and cyanotic.

• Jugular venous distention (JVD) frequently is present.

• Wheezing or rales may be heard on lung auscultation.

• Apical impulse frequently is displaced laterally.

• Cardiac auscultation may reveal aortic or mitral valvular abnormalities, S₃ or S₄.

• Lower extremity edema also may be noted, especially in the subacute process.

Causes:

• A variety of cardiac diseases cause CHF and pulmonary edema.

• The most common cause of heart failure is coronary artery disease, which is secondary to loss of left ventricular muscle, ongoing ischemia, or decreased diastolic ventricular compliance.

• Other disease processes include hypertension, valvular heart disease, congenital heart disease, other cardiomyopathies, myocarditis, and infectious endocarditis.

• CHF often is precipitated by cardiac ischemia or dysrhythmias, cardiac or extracardiac infection, pulmonary embolus, physical or environmental stresses, changes or noncompliance with medical therapy, dietary indiscretion, or iatrogenic volume overload.

• One also must consider systemic processes such as pregnancy and hyperthyroidism as precipitants of CHF.

Differentials

Altitude Illness - Pulmonary Syndromes
Anaphylaxis
Anemia, Acute
Bronchitis
Chronic Obstructive Pulmonary Disease and Emphysema
Dysbarism
Hyperventilation Syndrome
Myopathies
Pericarditis and Cardiac Tamponade
Pneumonia, Aspiration
Pneumonia, Bacterial
Pneumonia, Immunocompromised
Pneumonia, Mycoplasma
Pneumonia, Viral
Pneumothorax, Iatrogenic, Spontaneous and Pneumomediastinum
Pulmonary Embolism
Shock, Septic
Venous Air Embolism

Other Problems to be Considered:

The cardiac conditions combined with asthma or symptoms of chronic obstructive pulmonary disease (COPD) are difficult clinical challenges.

Workup

• Beta-natriuretic peptide

• Until recently, differentiating asthma and other pulmonary disease has been difficult in the acute setting, particularly because of the poor sensitivities and specificities of most elements of history and physical examination. The standard of care has been shotgun therapy, namely treating patients for both CHF and an acute pulmonary process such as asthma, with both diuretics and beta-agonists.

• The Breathing Not Properly Study has suggested that serum levels of beta-natriuretic peptide (BNP) and the BNP precursor, Pro-BNP, can help identify CHF as the origin of acute dyspnea. This study found sensitivities of 90% with specificities of 76%. Positive predictive value was 79% with a negative predictive value of 89%. Mueller found a reduction in hospital length of stay of 3 days when BNP levels were utilized. However, this study assumed an average length of stay of 11 days. The average length of stay in the United States for CHF exacerbations is approximately 4 days. In addition, although the time to initiation of therapy was reduced in this study from 90 to 60 minutes, the general practice in the United States is immediate initiation of shotgun therapy.

• In the primary care setting, Wright identified 305 patients with heart failure and then reevaluated them with or without the Pro-BNP result. Diagnostic accuracy improved from 52% to 60% without Pro-BNP and from 49% to 70% with Pro-BNP.

• Maisel identified in the Breathing Not Properly Study a 20% increase in patients with CHF who presented with dyspnea and a history of asthma or COPD but no prior history of CHF.
• Mueller found that BNP reduced time to discharge from 12 to 3 days and reduced costs of hospitalization by 15%

• BNP is available as a point-of-care test, with results available within 15 minutes; however, only Pro-BNP can be utilized concomitantly with nesiritide.

• Serum levels of BNP of <100 pg/mL are unlikely to be from CHF. In the Breathing Not Properly Study, BNP of 50 pg/mL increased sensitivity from 90% to 97% at a cost of reducing specificity. Levels of 100-500 pg/mL may be CHF. However, other conditions that also elevate right filling pressures, such as pulmonary embolus, primary pulmonary hypertension, end-stage renal failure, cirrhosis, and hormone replacement therapy, may also cause elevated BNP levels in this range. BNP levels of >500 pg/mL are most consistent with CHF.

• Serum lab values may identify prerenal azotemia or elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), or bilirubin, suggestive of a congestive hepatopathy. Cardiac enzymes and other serum markers for ischemia or infarction may be useful as well.

• Arterial blood gas (ABG) may be of benefit in evaluation of hypoxemia, ventilation/perfusion (V/Q) mismatch, hypercapnia, and acidosis.

• Mild azotemia, decreased erythrocyte sedimentation rate (ESR), and proteinuria are observed in early and mild-to-moderate disease.

• Increased creatinine, hyperbilirubinemia, and dilutional hyponatremia are observed in severe cases.

Imaging Studies:

• Chest radiography

• Although diagnostic tests are of limited benefit in acute CHF, chest radiography is the most useful tool. A recent study showed that 1 out 5 patients admitted to the hospital with CHF lacked signs of congestion on chest radiograph.

• Cardiomegaly may be observed with a cardiothoracic ratio greater than 50%. Pleural effusions may be present bilaterally or if they are unilateral more commonly observed on the right.

• Early CHF may manifest as cephalization of pulmonary vessels, generally reflecting a pulmonary capillary wedge pressure (PCWP) of 12-18 mm Hg. As the interstitial fluid accumulates, more advanced CHF may be demonstrated by Kerley B lines (PCWP: 18-25 mm Hg).

• Pulmonary edema is observed as perihilar infiltrates often in the classic butterfly pattern reflecting a PCWP greater than 25 mm Hg.

• Several limitations exist to the use of chest radiographs when attempting to diagnose CHF. Classic radiographic progression often is not found, and as much as a 12-hour radiographic lag from onset of symptoms may occur. In addition, radiographic findings frequently persist for several days despite clinical recovery.

• Emergency transthoracic echocardiography

• Emergency transthoracic echocardiography (ECHO) may help identify regional wall motion abnormalities as well as globally depressed or myopathic left ventricular function.

• ECHO may help identify cardiac tamponade, pericardial constriction, and pulmonary embolus.

• ECHO is also useful in identifying valvular heart disease, such as mitral or aortic stenosis or regurgitation.

Other Tests:

• Electrocardiogram (ECG) is a nonspecific tool but may be useful in diagnosing concomitant cardiac ischemia, prior myocardial infarction (MI), cardiac dysrhythmias, chronic hypertension, and other causes of left ventricular hypertrophy.

Procedures:

• No defined role exists for invasive monitoring devices such as central venous placement (CVP) lines. Time-consuming placement of pulmonary artery catheters has not been shown to prolong survival, even in the coronary care unit and, thus far, has not been well studied in the emergency department (ED) setting.

• Cardiac catheterization may be necessary for a complete evaluation and assessment of prognosis.

• Acute Respiratory Distress Syndrome
• Altitude Illness - Pulmonary Syndromes
• Anaphylaxis
• Anemia, Acute
• Bronchitis
• Chronic Obstructive Pulmonary Disease and Emphysema
• Dysbarism
• Hyperventilation Syndrome
• Myopathies
• Pericarditis and Cardiac Tamponade
• Pneumonia, Aspiration
• Pneumonia, Bacterial
• Pneumonia, Immunocompromised
• Pneumonia, Mycoplasma
• Pneumonia, Viral
• Pneumothorax, Iatrogenic, Spontaneous and Pneumomediastinum
• Pulmonary Embolism
• Shock, Septic
• Venous Air Embolism

• Heart Center
• Congestive Heart Failure Overview
• Congestive Heart Failure Causes
• Congestive Heart Failure Symptoms
• Congestive Heart Failure Treatment