Chapter 70: The Diagnosis and Management of Chronic Heart Failure
Which of the following physical examination signs is associated with a low cardiac index?
A. Elevated jugular venous pressure
C. Proportional pulse pressure < 25%
The answer is C. (Hurst’s The Heart, 14th Edition, Chap. 70) Many findings are attributed to heart failure. However, many findings such as peripheral edema are nonspecific (option B). By contrast, findings such as elevations in jugular venous pressure and third heart sound are strongly specific for heart failure but difficult to detect, and they suffer from a lack of reproducibility (options A and D).1,2 Furthermore, they are dependent on the patient’s body habitus and can be misleading in the presence of right ventricular dysfunction and/or tricuspid regurgitation. A proportional pulse pressure [(systolic – diastolic)/systolic] of < 25% suggests a cardiac index < 2.2 L . min–1 . m–2 (option C).3 The cardiovascular response to the Valsalva maneuver is a simple and highly sensitive bedside test for the estimation of volume status and the detection of LV systolic dysfunction, but it is not specifically associated with a low cardiac output (option E).
Which of the following biomarkers is predictive of outcomes from heart failure?
A. B-type natriuretic peptide (BNP)
The answer is E. (Hurst’s The Heart, 14th Edition, Chap. 70) Natriuretic peptides have an AHA/ACC Class I recommendation for the diagnosis of acute heart failure and establishment of prognosis in chronic heart failure.4 Cardiac troponin elevations in heart failure are associated with more severe disease and prognosis, but how treatments might be adjusted based on serum elevations remains unclear.5,6 It is reasonable currently to measure levels in the hospital setting to rule out an ischemic trigger and establish prognosis. Soluble ST2 and galectin-3 are predictive of adverse outcomes in chronic heart failure and are additive in their value to natriuretic peptides.7 Along with other prognostic factors, they can provide unique and objective information about the patient and are likely be included in future multimarker approaches to heart failure care.8 In chronic heart failure, the measurement of cardiac troponins, ST2, and galectin-3 has an AHA/ACC Class IIb recommendation for risk stratification.9