Congestive heart failure

Upon completion of this chapter, the reader will be able to:

• Understand how the clinical features of congestive heart failure (CHF) are altered in the older patient and how brain natriuretic peptide (BNP) levels may aid in making the diagnosis of CHF.

• Appreciate that CHF may be caused by systolic dysfunction or diastolic dysfunction of the heart.

• Understand the important role of angiotensin-converting enzyme (ACE) inhibitors in the prevention and treatment of CHF associated with left ventricular systolic dysfunction.

• List and justify the important additional roles of angiotensin receptor blocker (ARBs) drugs, beta-receptor blocker drugs, spironolactone, nesiritide, and biventricular pacing in the treatment of CHF associated with left ventricular systolic dysfunction.

• Implement treatment strategies for treatment of CHF associated with normal left ventricular systolic function.

CASE 1 Betty Postle (Part 1)

Betty Postle is an 83-year-old white woman who is a new patient for you, brought in by an out-of-town daughter, who notes her mother’s decreasing ability to take care of herself. Mrs. Postle is now dyspneic with minimal exertion. Her caregiver had a recent motor vehicle accident, and both Mrs. Postle and her daughter are unclear about Mrs. Postle’s medication regimen. On examination, her heart rate is 100 and blood pressure is 89/43 mmHg. She has crackles bilaterally extending halfway up the lung fields, jugular venous distention (JVD), and pedal edema. A II/VI pansystolic murmur is appreciated over her entire precordium with both S₃ and S₄ gallop. Chest x-ray (CXR) cardiac enlargement, pulmonary venous vascular congestion (enlarged hila that appear indistinct because of perivascular edema), and increased prominence of the pulmonary veins draining the upper lobes (cephalization of flow). Hemoglobin is 13 g, white blood cell count is normal, and urinalysis shows 1+ protein without active sediment. Blood urea nitrogen (BUN) and creatinine are 30 mg/dL and 1.6 mg/dL, respectively. Serum albumin is 3.6 g/dL.

1. What is the significance of the S₃ gallop? And the S₄?

2. What is the significance of the pedal edema?

3. How should treatment be initiated?

4. What further tests will guide optimal treatment? Why?

5. What factors precipitating congestive heart failure (CHF) should be ruled out?

Prevalence

CHF is the most common reason for hospitalization in Medicare patients. Prevalence is typically between 10% and 20% in elderly cohorts. The incidence increases tenfold from age 45 to age 85.¹ Five-year survival is less than 50% in both systolic and diastolic CHF.²

Risk factors and pathophysiology

Asymptomatic left ventricular systolic dysfunction (ALVSD) frequently progresses to congestive heart failure (CHF). This progression can be retarded by angiotensin-converting enzyme (ACE) inhibitors.³ ALVSD is a function of age. In community-based studies, almost all the young people with left [ventricular] systolic dysfunction (left ventricular ejection fraction [LVEF] greater than 30) are asymptomatic; in men older than age 65, half were asymptomatic, and in older women, only 27% were asymptomatic.⁴ This may be because the symptoms of CHF are manifestations of compensatory mechanisms used to maintain cardiac output. Data for patients older than age 75 are not available.

Left ventricular systolic dysfunction is the cause of CHF in the elderly patient in 50% to 60% of CHF cases. In the remainder, LVEF is normal but evidence of impaired ventricular filling is present.⁵ If significant valvular or pericardial disease is absent, CHF is then attributed to diastolic dysfunction. Normal LVEF, determined by echocardiography or nuclear techniques, is generally 50% or more. Significant left ventricular systolic dysfunction is defined as an LVEF less than 40%. There is no simple measure of diastolic function. CHF resulting from diastolic dysfunction may be so common in the elderly because aging itself results in a stiff, poorly relaxing left ventricle. Disease processes add to these aging effects.

CHF, a more advanced stage of heart failure (strictly defined as impairment in heart function leading to symptoms such as fatigue and dyspnea because of inadequate cardiac output), is defined as the presence of evidence of fluid retention manifested clinically by edema and congestion of the veins of the pulmonary and systemic circuits.

Differential diagnosis and assessment

Diagnosis

Classically, the diagnosis of CHF is based on history, physical examination, and chest x-ray (CXR) examination.⁶ Brain natriuretic peptide (BNP) testing has altered this approach. Diagnosis of CHF in the elderly may be difficult because the history is often atypical (Box 38-1), or unobtainable, or because the symptoms are minimized by the patient or attributed to age. One of the most common atypical presentations of CHF is delirium, which is frequently superimposed on preexisting dementia.

BOX 38-1 CLASSIC AND ATYPICAL MANIFESTATIONS OF CONGESTIVE HEART FAILURE IN THE ELDERLY

Classic (Noncerebral)	Atypical	Atypical (Cerebral)
Dyspnea Orthopnea Paroxysmal nocturnal Peripheral edema Unexplained weight gain Weakness Poor exercise tolerance Abdominal pain Fatigue	Chronic cough Insomnia Weight loss Nausea Nocturia Syncope	No history Falls Anorexia, dyspnea Behavioral disturbances Decreased functional status