Introduction: Patients with hypertension and left ventricular hypertrophy (LVH) are at increased risk of cardiovascular complications and the current guidelines recommend echocardiography for determination of left ventricular mass.
Material and methods: We investigated the suitability of repeated measurements to determine the left ventricular mass (LVM) in 30 patients with previously untreated essential hypertension before and after one year of antihypertensive treatment. Fourteen normotensive healthy persons served as controls. Six M-mode echocardiographic measurements (transducer was turned off and on again each time) were performed.
Results: The probability of misclassifying a person with LVH (> 130 g/m(2)) as having normal LVM or vice versa was calculated as a function of the number of measurements. The probability was high for single measurements, but was substantially reduced by performing six repeated measurements. Thus, the risk of misclassification was reduced from 20% to 6% in persons with LVM of 120 g/m(2) or 140 g/m(2) and from 13% to 1% in persons with LVM of 115 or 145 g/m(2). However, for persons whose LVM were close to 130 g/m(2), the probability for misclassifications remained high 20% despite repeated measurements.
Discussion: Even though averaged LVM measurements within groups demonstrate clear results, considerable intraindividual variation remains, and in daily clinical practice repeated measurements of LVM are recommended.