• erectile dysfunction;
  • cardiovascular health;
  • penile haemodynamics


  • To evaluate whether peripheral arterial tone (PAT) can predict the results of penile colour flow Doppler in the evaluation of erectile dysfunction (ED).

Patients and Methods

  • Fifty men presenting to an ED clinic were tested with an Endo-PAT2000 machine (Itamar Medical, Caesarea, Israel), which assessed augmentation index (AI), a measure of arterial stiffness, and reactive hyperaemia index (RHI), a measure of endothelial vasodilatation.
  • Penile haemodynamics were measured and used to identify both arterial insufficiency (abnormal peak systolic velocity [PSV]) and veno-occlusive disease (abnormal end diastolic velocity [EDV]) after pharmacological erection with prostaglandin E1 using colour flow Doppler.
  • Between-group comparisons were carried out using a Wilcoxon rank-sum test for continuous variables and a chi-squared test for categorical variables. Simple and multivariable logistic regression analyses were used to analyse the correlation between outcome measures.


  • Using Doppler analysis, 58% of patients were found to have arterial insufficiency (abnormal PSV) and 48% had veno-occlussive disease (abnormal EDV).
  • Using the Endo-PAT machine, 44% of patients were found to have increased arterial stiffness (abnormal AI) and 54% had decreased endothelial relaxation (abnormal RHI).
  • Neither AI nor RHI were correlated with PSV or EDV. The closest association was between high AI and low PSV, with a sensitivity of 0.55 and specificity of 0.71.


  • In our patient cohort, PAT did not reliably predict the results of penile Doppler.
  • The two tests appear to measure different although potentially complementary aspects of the local and systemic vasculature.