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[MEDSCAPE快速测验]:检查你对心功能衰竭关键知识的了解(5/6)
2018年05月15日 临床话题, 基本知识 暂无评论

Fast Five Quiz: Test Your Knowledge on Key Aspects of Heart Failure

Yasmine S. Ali, MD, MSCI

March 21, 2018

Heart failure is the pathophysiologic state in which the heart, via an abnormality of cardiac function (detectable or not), fails to pump blood at a rate commensurate with the requirements of the metabolizing tissues or is able to do so only with an elevated diastolic filling pressure. In general, the mortality rate following hospitalization for patients with heart failure is 10.4% at 30 days, 22% at 1 year, and 42.3% at 5 years, despite marked improvement in medical and device therapy.

Heart failure is a worldwide problem. The most common cause of heart failure in industrialized countries is ischemic cardiomyopathy, with other causes, including Chagas disease and valvular cardiomyopathy, assuming a more important role in developing countries. However, in developing nations that have become more urbanized and more affluent, eating a more processed diet and leading a more sedentary lifestyle have resulted in an increased rate of heart failure, along with increased rates of diabetes and hypertension. According to 2017 American Heart Association (AHA) data, heart failure affects an estimated 6.5 million Americans aged 20 years and older.

How much do you know about important aspects of presentation, diagnosis, and treatment? Test yourself with this quick quiz.

Question 1: Which of the following is accurate about the etiology of heart failure?

Answer 1: Thyrotoxicosis, multiple myeloma, and profound anemia can precipitate the clinical presentation of heart failure

Because of increased myocardial oxygen consumption and demand beyond a critical level, the following high-output states can precipitate the clinical presentation of heart failure:

  • Profound anemia
  • Thyrotoxicosis
  • Myxedema
  • Paget disease of bone
  • Albright syndrome
  • Multiple myeloma
  • Glomerulonephritis
  • Cor pulmonale
  • Polycythemia vera
  • Obesity
  • Carcinoid syndrome
  • Pregnancy
  • Nutritional deficiencies (eg, thiamine deficiency, beriberi)

The most common cause of decompensation in a previously compensated patient with heart failure is inappropriate reduction in the intensity of treatment, such as dietary sodium restriction, physical activity reduction, or drug regimen reduction. Uncontrolled hypertension is the second most common cause of decompensation, followed closely by cardiac arrhythmias (most commonly, atrial fibrillation).

Underlying causes of systolic heart failure include the following:

  • Coronary artery disease
  • Diabetes
  • Hypertension
  • Valvular heart disease (stenosis or regurgitant lesions)
  • Arrhythmia (supraventricular or ventricular)
  • Infections and inflammation (myocarditis)
  • Peripartum cardiomyopathy
  • Congenital heart disease
  • Drugs (either recreational, such as alcohol and cocaine, or therapeutic drugs with cardiac side effects, such as doxorubicin)
  • Idiopathic cardiomyopathy
  • Rare conditions (endocrine abnormalities, rheumatologic disease, neuromuscular conditions)

Underlying causes of diastolic heart failure include the following:

  • Coronary artery disease
  • Diabetes
  • Hypertension
  • Valvular heart disease (aortic stenosis)
  • Hypertrophic cardiomyopathy
  • Restrictive cardiomyopathy (amyloidosis, sarcoidosis)
  • Constrictive pericarditis

Underlying causes of acute heart failure include the following:

  • Acute valvular (mitral or aortic) regurgitation
  • MI
  • Myocarditis
  • Arrhythmia
  • Drugs (eg, cocaine, calcium channel blockers, or beta-blocker overdose)
  • Sepsis

Underlying causes of high-output heart failure include the following:

  • Anemia
  • Systemic arteriovenous fistulas
  • Hyperthyroidism
  • Beriberi heart disease
  • Paget disease of bone
  • Albright syndrome (fibrous dysplasia)
  • Multiple myeloma
  • Pregnancy
  • Glomerulonephritis
  • Polycythemia vera
  • Carcinoid syndrome

For more on the etiology of heart failure, read here.

Question 2: Which of the following is accurate about the presentation and physical examination of patients with heart failure?

Answer 2: In general, elevated jugular venous pressure is the most reliable indicator of fluid volume overload in older patients

Systemic venous hypertension is manifested by jugular venous distention. Normally, jugular venous pressure declines with respiration; however, it increases in patients with heart failure, a finding known as the Kussmaul sign (also found in constrictive pericarditis). This reflects an increase in right atrial pressure and, therefore, right-sided heart failure. In general, elevated jugular venous pressure is the most reliable indicator of fluid volume overload in older patients, and thorough evaluation is needed.

Protodiastolic (S3) gallop is the earliest cardiac physical finding in decompensated heart failure in the absence of severe mitral or tricuspid regurgitation or left-to-right shunts. The presence of an S3 gallop in adults is important, pathologic, and often the most apparent finding on cardiac auscultation in patients with significant heart failure.

The following may occur in elderly patients with advanced heart failure, particularly in those with cerebrovascular atherosclerosis:

  • Confusion
  • Memory impairment
  • Anxiety
  • Headaches
  • Insomnia
  • Bad dreams or nightmares
  • Rarely, psychosis with disorientation, delirium, or hallucinations

Nocturia may occur relatively early in the course of heart failure. Recumbency reduces the deficit in cardiac output in relation to oxygen demand, renal vasoconstriction diminishes, and urine formation increases. Nocturia may be troublesome for patients with heart failure because it may prevent them from obtaining much-needed rest. Oliguria is a late finding in heart failure, and it is found in patients with markedly reduced cardiac output from severely reduced left ventricular (LV) function.

For more on the presentation and physical examination of patients with heart failure, read here.

Question 3: Which of the following is accurate regarding the American College of Cardiology (ACC)/AHA staging for heart failure?

Answer 3: Stage C patients have structural heart disease and current or previous symptoms of heart failure and should undergo dietary sodium restriction

ACC/AHA stage A patients are at high risk for heart failure but do not have structural heart disease or symptoms of heart failure. Thus, management in these cases focuses on prevention through reduction of risk factors.

ACC/AHA stage B patients are asymptomatic, with LV dysfunction from previous MI, LV remodeling from LV hypertrophy (LVH), and asymptomatic valvular dysfunction, which includes patients with New York Heart Association (NYHA) class I heart failure. In addition to the heart failure education and aggressive risk factor modification used for stage A, treatment with an ACE inhibitor/angiotensin-receptor blocker (ACEI/ARB) and/or beta-blockade is indicated.

ACC/AHA stage C patients have structural heart disease and current or previous symptoms of heart failure; ACC/AHA stage C corresponds with NYHA class I-IV heart failure. The preventive measures used for stage A disease are indicated, as is dietary sodium restriction.

ACC/AHA stage D patients have refractory heart failure (NYHA class IV) that requires specialized interventions. Therapy includes all of the measures used in stages A, B, and C. Treatment considerations include heart transplantation or placement of an LV assist device in eligible patients, pulmonary catheterization, and options for end-of-life care. For palliation of symptoms, continuous intravenous infusion of a positive inotrope may be considered.

For more on the staging of heart failure, read here.

Question 4: Which of the following is accurate regarding the workup of heart failure?

Answer 4: Abnormal ECG findings are likely in patients with heart failure, and normal findings are suggestive of an alternative diagnosis

A screening ECG is reasonable in patients with symptoms suggestive of heart failure. The presence of left atrial enlargement and LVH is sensitive (although nonspecific) for chronic LV dysfunction. ECG findings are unlikely to be completely normal in the presence of heart failure; therefore, an alternative diagnosis should be sought in such cases.

Doppler echocardiography, along with 2-D echocardiography, may play a valuable role in determining diastolic function and in establishing the diagnosis of diastolic heart failure. Approximately 30%-40% of patients presenting with heart failure have normal systolic function but abnormal diastolic relaxation. The primary finding to differentiate diastolic heart failure is the presence of a normal ejection fraction; however, note that findings of diastolic dysfunction are common in the elderly and may not be associated with clinical heart failure. Because the therapy for this condition is distinctly different from that for systolic dysfunction, establishing the appropriate etiology and diagnosis is essential.

Careful evaluation of the patient's history and physical examination (including signs of congestion, such as jugular venous distention) can provide important information about the underlying cardiac abnormality in heart failure. However, other studies and/or tests may be necessary to identify structural abnormalities or conditions that can lead to or exacerbate heart failure. Endomyocardial biopsy is indicated only when a specific diagnosis is suspected that would influence therapy in patients presenting with heart failure.

BUN and creatinine levels can be within reference ranges in patients with mild-to-moderate heart failure and normal renal function, although BUN levels and BUN/creatinine ratios may be elevated.

For more on the workup of heart failure, read here.

Which of the following is accurate in the treatment of heart failure?

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