Exercise Capacity and Left Ventricular Function

To the Editor: In their analysis of factors associated with exercise capacity, Dr Grewal and colleagues¹ identified abnormalities of left ventricular diastolic function as a factor independent of other echocardiographic factors. However, the authors appear to have omitted left ventricular mass and left ventricular hypertrophy as one of the echocardiographic variables in their multivariate analysis.

Although left ventricular diastolic function may be independent of, or precede, left ventricular hypertrophy in patients with stage 1 or treated hypertension,^2- 3 we have previously demonstrated that both left ventricular mass and diastolic function are related to exercise capacity in patients with newly diagnosed or uncontrolled hypertension of stage 2 or greater.⁴ Because in the study by Grewal et al the impaired diastolic function group had a higher prevalence of hypertension, increased left ventricular mass could be a major confounder mediating the relationship between exercise performance and diastolic function. In addition, because of the strong relationship between left ventricular mass and cardiovascular morbidity and mortality,⁵ we believe that it is important for the authors to explore the relationship between exercise capacity and left ventricular mass in their population.