Investigation of a patient with collapse The history from the older patient may be less reliable, however a careful history often allows syncopal episodes to be classified into broad diagnostic categories. Elderly patients may have amnesia for their collapse. A witness history, available in only 40–60% of cases, can thus be invaluable. Witnessed features of prodrome (i.e. pallor, sweating, loss of consciousness or fitting) and clinical characteristics after the event can all help in building a diagnostic picture. Physical examination should include an assessment of blood pressure in the supine and erect position, a cardiovascular examination to look for the presence or absence of structural heart disease (including aortic stenosis, mitral stenosis, outflow tract obstruction, atrial myxoma or impaired left ventricular function) and auscultation for carotid bruits. The 12- lead electrocardiogram (ECG) remains an important tool in the diagnosis of arrhythmic syncope. Up to 11% of syncopal patients have a diagnosis assigned from their ECG. More importantly those with a normal 12-lead ECG (no QRS or rhythm disturbance) have a low likelihood of arrhythmia as a cause of their syncope and are at low risk of sudden death. Thus the history and physical examination can guide you as to the more appropriate diagnostic tests for the individual patient and would include the following:
  • ECG
  • 24 hour ECG
  • 24 hour BP
  • Carotid sinus massage – supine and erect (only if negative supine)
  • External loop recorder
  • Electrophysiological studies
  • Head up tilt test
  • CT head and EEG if appropriate
  • Implantable loop recorder
Who should have a tilt test?
Kenny et al in 1986 were the first to demonstrate the value of head up tilt testing in the diagnosis of unexplained syncope.1 There is a broad group of hypotensive syndromes and conditions where head up tilt testing should be considered – patients with recurrent syncope or presyncope and high risk patients with a history of a single syncopal episode (serious injury during episode, driving) where no other cause for symptoms is suggested by initial history, examination or cardiovascular and neurological investigations. Tilt table testing may also be of use in the assessment of elderly patients with recurrent unexplained falls and in the differential diagnosis of convulsive syncope, orthostatic hypotension, postural tachycardia syndrome, psychogenic and hyperventilation syncope and carotid sinus hypersensitivity. What do you do if you make a diagnosis of vasovagal syncope on history and head up tilt test?

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