Chapter 20 Heart Failure

Heart Failure—Definition Heart failure is a clinical syndrome characterized by shortness of breath, dyspnea on exertion (DOE), paroxysmal nocturnal dyspnea (PND), orthopnea, and peripheral or pulmonary edema. Heart failure is a general term used to describe the general clinical syndrome regardless of the kind of heart failure or the etiology that produces the symptoms. The revised guidelines recently published by a joint American College of Cardiology (ACC) and American Heart Association (AHA) task force use the preferred term heart failure rather than congestive heart failure because patients with chronic heart failure rarely demonstrate the rales and alveolar edema associated with congestion.

Acute Versus Chronic Describes the onset and intensity of symptoms Acute: sudden onset over days or hours Chronic: develop over months to years If the cause of acute symptoms is not reversed, then heart failure will become chronic.

Question Left ventricular diastolic heart failure is characterized by which of the following? A. Pulmonary congestion on CXR B. Ejection fraction greater than 40% C. Decreased contractility D. Decreased ventricular volume

Answer A. Pulmonary congestion on CXR Rationale: In left ventricular diastolic failure, the left ventricle is unable to fill completely, resulting in diminished cardiac output with a normal or high ejection fraction. Conditions associated with the development of diastolic failure are stiff and poorly compliant ventricles from aging, uncontrolled hypertension, or volume overload, combined with a fast heart rate or atrial fibrillation.

Left-Sided Heart Failure Failure of the left ventricle to fill or empty properly Leads to increase in ventricular pressures and pulmonary vascular congestion Systolic dysfunction Decrease in contractility EF less than 40% Diastolic dysfunction Impaired relaxation and filling EF may be as high as 80%.

Right-Sided Heart Failure Failure of the right ventricle to pump adequately Left-sided heart failure is the most common cause. Can result from pulmonary disease or pulmonary hypertension PE is the common cause of acute right-sided heart failure.

Classification Systems New York Heart Association Functional Classification Measure of how much the symptoms of heart failure limit the activities of patients American College of Cardiology/American Heart Association Guidelines Outline four stages of heart failure that are useful for organizing the prevention, diagnosis, management, and prognosis for patients with heart failure

Question Is the following statement true or false? The underlying result of heart failure is insufficient cardiac output.

Answer True Rationale: The underlying result of all types of heart failure is insufficient cardiac output. That is, the volume of blood pumped by the heart in 1 minute is inadequate. Some patients may have a normal cardiac output at rest, but they do not have the reserve function to increase cardiac output to meet the increased demands of exercise, hypoxemia, or anemia.

Factors That Determine Cardiac Output Underlying result of heart failure is insufficient CO. Oxygen demand CO increases to meet increased O2 demand. Mechanical factors Stroke volume and heart rate Neurohormonal mechanisms Catecholamines Renin–angiotensin–aldosterone system

Pathophysiology Cardiomyopathy Dysrhythmias Atrial dysrhythmias Ventricular dysrhythmias Acute decompensated heart failure Triggered by alcohol, anemia, hypoxemia, hypertension, ischemia, and worsening left ventricular function

Assessment History Onset Duration Comorbid diseases Medications Psychosocial factors Substance abuse

Physical Examination General findings Vital signs Neck Lungs Heart Abdomen Extremities

Laboratory Studies CBC Iron studies Thyroid function tests Electrolytes, BUN BNP LFTs HIV Lipid panel

Diagnostic Studies Electrocardiography Echocardiography Radionuclide ventriculography Chest radiography Exercise testing

Question All of the following are indications for hemodynamic monitoring except which of the following? A. The patient does not respond to empirical therapy for heart failure. B. The patient has an increased BNP. C. Differentiation between pulmonary and cardiac causes of respiratory distress is necessary. D. Complex fluid status needs to be evaluated.

Answer B. The patient has an increased BNP. Rationale: The first type is the patient who is empirically treated with inotropes and intravenous (IV) diuretics but has not responded appropriately to diuresis with improved symptoms. The second type of patient has both COPD and heart failure. At times, only pulmonary artery pressure measurements can differentiate the source of the current decompensation. The third type of patient continues to have congestion associated with peripheral edema or ascites and has renal function values indicating worsening azotemia.

Hemodynamics Indications for hemodynamic monitoring The patient does not respond to empirical therapy for heart failure. Differentiation between pulmonary and cardiac causes of respiratory distress is necessary. Complex fluid status needs to be evaluated. Pulse oximetry monitoring

Management of Acute Decompensation of Heart Failure Airway and breathing Intubation Diuresis Circulation Optimize hemodynamics. Increase contractility. Vasodilation Heart rate

Management of Chronic Heart Failure Pharmacological treatment Angiotensin-converting enzyme inhibitors Digoxin Diuretics Spironolactone Calcium channel blockers Nitrates

Nonpharmacological Treatment Role of the patient Sodium restriction, alchohol cessation, exercise, medication adherence, fluid restriction Implantable cardioverter–defibrillator For syncopal episodes or survivor of sudden death Biventricular pacing

Patient Education Medications Diet Daily weights Activity When to call the doctor