Objective: To obtain information on how often electrocardiograms (ECG) should be carried out during hypertense patients' follow-up.
Design: A retrospective, descriptive study.
Setting: La Mina Primary Care Centre.
Patients: Out of 1780 hypertense patients over 14 years old monitored at our Health Centre, 352 were selected by random sampling.
Measurements and main results: Their first ECG after the AHT diagnosis was analysed. Those patients with a normal initial ECG, a minimum of one year's monitoring, and absence of a chronic limitation of air flow, diabetes mellitus or cardiopathy were included in the study. The ECGs following the first ECG were analysed sequentially until an anomalous ECG was detected. Final sample: 98 patients (average age 53, SD 12.8; 33 men and 65 women). 89 (91.8%) had light-to-moderate AHT. The average interval between the initial normal ECG and the first pathological ECG was 36 months (SD 16.9). The most common electrocardiographic irregularities were the T minor wave (34.5%), the greater unevenness of the ST (17.2%) and left ventricular hypertrophy (13.8%). A total of 29 patients presented a pathological ECG during an average monitoring period of 61 months (C.I. 95%; 50-72). These were only significantly different from the remaining 69 as regards age. Those patients over 54 (n = 51) had significantly more irregularities (21) than those under 55 (n = 47) (8 irregularities) (p = 0.006), the main increase being between the ages of 55 and 60.
Conclusions: The recommendation to carry out an ECG every 2 or 3 years when monitoring a hypertense patient with a normal initial ECG and without additional pathologies, could be extrapolated from our study. The time interval could be shortened for older patients.