KEY POINTS FOR CLINICIANS
- Heart failure is an increasingly common problem in primary care, with a mortality rate higher than that of most cancers.
- The absence of dyspnea on exertion or a normal electrocardiogram (ECG) result indicates that heart failure is unlikely; a gallop rhythm or laterally displaced apical rhythm is strong evidence in favor of heart failure.
- The history and physical examination and ECG alone are usually inadequate to confirm diagnosis of left ventricular systolic dysfunction, and echocardiography remains the gold standard to confirm the diagnosis.
Heart failure is increasing in incidence and prevalence; it currently affects 0.4% to 2% of the general population and 8% to 10% of the elderly.1,2 In the United States, heart failure is the second most common cardiovascular reason for an outpatient visit in the ambulatory care setting and remains the most common cause for hospitalization among patients older than 65 years.3 The total cost for heart failure management in 1999 was estimated to approach $56 billion.4 Those suffering with this illness experience high levels of morbidity and mortality5 that are reflected in the workloads of both primary and secondary care. Heart failure admission rates are rising, and the prognosis of heart failure has been compared with that of malignancy, with a 6-year mortality rate of 84% in men and 77% in women.6,7
A number of heart failure guidelines8-14 provide direction regarding “best practice” with regard to diagnosis and management. These guidelines have all been produced by expert panels and base their evidence on systematic critical reviews of the literature, plus expert consensus opinion. The evidence underlying the development of these guidelines ranges from well-conducted randomized controlled trials to expert opinion. These guidelines all emphasize the ways in which approaches to the diagnosis and management of heart failure have altered substantially in recent years and are continuing to change rapidly. The need to detect heart failure at an early stage to slow the progression of left ventricular systolic dysfunction (LVSD) is now well accepted.15
The following provides an overview of the current recommended approaches to diagnosis, focusing specifically on LVSD, the most common type of heart failure and also the usual focus of most guidelines. Accurate diagnosis of LVSD is the single most important step in management.16 An adequate diagnosis should establish the existence of heart failure, differentiate systolic from diastolic dysfunction, and identify the main underlying cause and any subsidiary diagnoses that may exacerbate heart failure. The etiology of heart failure and the presence of exacerbating factors or other diseases need to be carefully considered in all patients. Coronary artery disease remains the most common potentially reversible etiologic factor in heart failure.8
Using the history and physical examination
The major symptoms of heart failure are fatigue, exercise intolerance, exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and dependent edema. However, such symptoms are similar to those of many other diseases, particularly pulmonary diseases. For example, exertional dypsnea is a common symptom in heart failure but can be due to a wide range of other causes, such as chronic obstructive pulmonary disease, interstitial lung disease, asthma, respiratory infection, deconditioning, or obesity. Many patients with impaired left ventricular function may have no obvious symptoms.17 This highlights the importance of exploring past medical and medication history as these contribute to the overall clinical assessment.
Physical findings that may support a diagnosis of heart failure include raised jugular venous pressure, peripheral edema not due to venous insufficiency, presence of a third heart sound, gallop rhythm, laterally displaced apical impulse, tachycardia, and pulmonary rales that do not clear with coughing. Although clinical findings are particularly useful in acute severe heart failure at the time of hospitalization,18 it is difficult to accurately diagnose mild heart failure in the community on the basis of clinical grounds alone.2,9 The value of different symptoms and aspects of the medical history and use of medications in the evaluation of potential heart failure patients have been examined by researchers.18, 20-23 Similarly, the utility of physical examination has also undergone investigation.18,20,22-28Table 1 summarizes the study findings with regard to clinical symptoms and signs.
Davie and colleagues20 assessed the value of symptoms, past history, medications, and signs in the evaluation of patients who may have LVSD. No one clinical feature predicted LVSD, as assessed by echocardiography with sensitivity, specificity, and a high positive and negative predictive value. Absence of dyspnea on exertion essentially ruled out heart failure (negative likelihood ratio [LR-] = 0.06), while gallop rhythm (positive likelihood ratio [LR+] = 24.0), laterally displaced apical impulse (LR+ 16.4), and elevated jugular venous pulsation (LR+ = 8.9) are strong evidence in favor of the diagnosis. Furthermore, the combination of history of myocardial infarction and displaced apex on physical examination, although not particularly sensitive (39% sensitivity) was very specific (99% specificity) with high positive (89%) and negative (89%) predictive values. The authors also suggest that a breathless patient with a past history of myocardial infarction and a displaced apex beat on physical examination will almost certainly have heart failure and, if resources are limited, may not need echocardiography to confirm the diagnosis. However, less than 50% of breathless patients will have this combination, and the other half would therefore need echocardiography as the gold standard diagnostic tool for LVSD.