I first started using the V scan myself over four years ago, and I have found this hand-held mobile device extremely useful for providing rapid and important diagnostic information at the bedside. The quality of the images of the V scan are usually of sufficiently high quality to make a useful clinical assessment. It is usually possible to make a fair assessment of systolic function of the left ventricle. I have also found that the identification of a dilated right heart has often been very useful for diagnosing massive pulmonary emboli – quite frequently when this diagnosis would not otherwise have been suspected. Valve lesions of significance are invariably pretty obvious and the images are usually adequate to identify vegetations as well. Pericardial effusion is readily detected.
In this issue, Fabich et al. describe the use of the V scan used by cardiac sonographers providing an outreach service to general practice. Two groups of patients were studied. The first group (n=163) had scans based on the presence of any of the following criteria: cardiac murmur, cardiac symptoms or history, atrial fibrillation, chronic obstructive pulmonary disease (COPD) with disproportionate dyspnoea or age ≥75 years. There were a further 90 patients (second group) studied with the V scan without any clear clinical indication.
The authors found that the patients with clinical indications for the V scan (i.e. the first group) had normal scans in 49%, mildly abnormal scans in 41% and there were 16 patients (10%) with significant abnormalities. In contrast, none of the patients without any obvious indication for a V scan (i.e. the second group) had significantly abnormal scans.
These findings appear to endorse the use of a hand-held ultrasound device, but does this herald the demise of the stethoscope?
The place of the stethoscope
V-scan technology is extremely useful and, undoubtedly, is an important extension of the normal clinical examination. However, the stethoscope, while not particularly sensitive, is a relatively specific tool. Apart from auscultation of the heart itself, the stethoscope is, of course, invaluable in diagnosing lung disease, and is complementary to the chest X-ray. In fact, there are findings detectable by the stethoscope, which are not apparent on chest radiography and, of course, vice versa.
With respect to the heart, a pericardial friction rub can be heard with a stethoscope but could not be identified with a V scan. The stethoscope is also a very quick tool for detecting obvious murmurs, which can be more clearly studied with the V scan and, of course, the echocardiogram.
A stethoscope, in experienced hands, can be used to assess the significance and severity of heart valve lesions. The auscultatory features of aortic stenosis do (to me) give a pretty clear indication of the severity of aortic stenosis, which is complementary to the evidence available from an echocardiogram (or V scan).
Hand-held ultrasound is undoubtedly an important addition to the clinical examination but, as the authors suggest, without any clinical indication it is a waste of time.
In conclusion, while I believe it will play an increasingly important role in the future of the cardiological clinical examination; hand-held cardiac ultrasound devices are unlikely to replace cardiac auscultation any day soon.
Conflict of interest