Letters

Can heart failure be diagnosed in primary care?

BMJ 2000; 321 doi: https://doi.org/10.1136/bmj.321.7273.1414/b (Published 02 December 2000) Cite this as: BMJ 2000;321:1414

Chest radiography is still useful

  1. Chris Davidson (chrisdavidson{at}compuserve.com), cardiologist
  1. Sussex Cardiac Centre, Royal Sussex County Hospital, Brighton BN2 5BE
  2. University of Birmingham, Birmingham B15 2TT

    EDITOR—In his editorial on diagnosing heart failure in primary care Hobbs fails to mention the value of chest radiography.1 As every medical student knows, a chest x ray film provides information on cardiac size and the major cardiac structures, and more fundamentally on any respiratory cause of breathlessness. It is even more extraordinary that Caruana et al do not mention chest radiography in the diagnostic process in their paper, although their study focused particularly on excluding other causes of the patients' symptoms.2

    The current obsession with open access echocardiography is tending to unnerve general practitioners, who feel that they cannot now diagnose heart failure without showing abnormal left ventricular function. In fact, in most patients the disease can be diagnosed and treated with a knowledge of the history, clinical findings, chest x ray film, and electrocardiography.3

    Experience of open access echocardiography at this centre over two years was that it added little to the diagnostic process for those in primary care, except in patients who had a heart murmur.4 Given the rising demands for specialist technicians and medical time, it is neither realistic nor desirable to use echocardiography as a screening test for heart failure. Assay of brain natriuretic peptide may prove better,3 but surely the first test in primary care for a breathless patient should be chest radiography.

    References

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    Author's reply

    1. Richard Hobbs (F.D.R.Hobbs{at}bham.ac.uk), professor of primary care and general practice
    1. Sussex Cardiac Centre, Royal Sussex County Hospital, Brighton BN2 5BE
    2. University of Birmingham, Birmingham B15 2TT

      EDITOR—As Davidson points out, the chest x ray film is viewed by many as having an important role in the routine investigation of suspected heart failure. But as far as I am aware there are no reliable data on the performance of chest radiography in diagnosing heart failure,1 or indeed in diagnosing respiratory causes of breathlessness. To be certain of the validity of chest radiography in this role would require empirical testing.

      If heart failure is sufficiently established, cardiac enlargement (cardiothoracic ratio >50%) may be present. But the correlation between the cardiothoracic ratio and left ventricular function is poor. Cardiomegaly depends on both the severity of haemodynamic disturbance and its duration. It will not be present in early left ventricular systolic dysfunction, which is worth identifying since treatment delays progression.2 In decompensated heart failure radiographic features other than cardiomegaly may be present, such as pulmonary congestion or pulmonary oedema. But again, such features occur when disease is well established.

      Echocardiography is therefore required to distinguish reliably between different causes of heart failure as different treatments are indicated, and to detect abnormalities at an earlier stage than chest radiography. Furthermore, echocardiography is less invasive, with no ionising dose to the patient or environment. As far as cost goes, if there was sufficient access to echocardiography it would be unlikely to cost much more than chest radiography since both need skilled operators and similar timing (and presumably capital costs for chest radiography are much higher).

      Davidson reinforces the importance of considering respiratory disease in patients presenting with breathlessness when heart failure is a possibility. But chest radiography is not necessarily reliable in diagnosing respiratory causes of breathlessness: for example, it would not exclude asthma or early stages of chronic obstructive airway disease. Indeed, spirometry rather than chest radiography is an appropriate alternative test. Naturally, the probability of respiratory disease is greater if the patient has no history of cardiovascular disease.

      In most circumstances in the United Kingdom any patient suspected of having heart failure should be offered cardiac imaging. As well as reliably diagnosing left ventricular dysfunction and valve disease, the reasonably objective information provided by echocardiography should reduce the diagnostic uncertainty that so often results in undertreatment and underdosing. Relying on less specific tests, such as chest radiography, is likely to perpetuate the current undermanagement of this complex problem. Patients with heart failure deserve evidence based treatments, which in turn require the diagnosis to be as certain as possible.3

      References

      1. 1.
      2. 2.
      3. 3.
      View Abstract

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