[Hypertrophic myocardiopathy with isoelectric T waves]. / Miocardiopatía hipertrófica con ondas T isoeléctricas.

INTRODUCTION AND OBJECTIVES: The lack of specificity of electrocardiographic (ECG) recording showing isoelectric T-waves often leads to diagnostic doubts. This study attempts to demonstrate that asymptomatic patients who demonstrate benign forms of hypertrophic cardiomyopathy may be identified from a typical ECG pattern showing isoelectric T-waves. METHODS: In 45 out of 5,126 asymptomatic healthy aircrew members, an ECG pattern which showed isoelectric T-waves in all leads, but were normal in V2 and V3, was found. 12 of them had negative T-waves in III and aVF leads. Cardiac echo-Doppler, Bruce test and 24-hour Holter recordings were performed in 29 of the 45 cases; all were males aged 30-55 (43.1 +/- 7.1) without any associated disorder nor engaged in heavy exercise, and a control group of 15 healthy subjects. In each of the 29 cases, 2-21 ECG's (11.1 +/- 6.3) performed over a period of 2 to 20 years (13.0 +/- 5.9) were reviewed. RESULTS: In 23 of the 29 cases (79.3%), echo-Doppler criteria of non obstructive mild hypertrophic cardiomyopathy were found. T-waves became normal during exercise testing, returning to isoelectric during recovery, in 19 of the 23 cases. In 17 of these cases, reversible T-wave changes were observed between successive ECG's; T-wave changes became clearly negative when the level of exercise was increased. Holter recordings did not show pathological findings. CONCLUSIONS: We believe that echo-Doppler studies must be performed in asymptomatic patients showing the ECG pattern described above, because they are strongly suspicious of having mild hypertrophic cardiomyopathy.

[Value of heart rate recordings in selecting the initial treatment of hypertension]. / Interés de la frecuencia cardíaca en la elección del tratamiento inicial de la hipertensión.

60 patients with mild arterial hypertension are studied, divided into three groups according to their heart rate (HR): 20 with heart rate below 70 b.p.m.; 20 with heart rate between 70 and 80 b.p.m., and 20 with heart rate above 80 b.p.m. In every group, 10 patients were treated with atenolol and the other 10 patients with chlorthalidone. The cases of bad tolerance or bad response to any of these drugs were included in the other subgroup, so that a total number of 71 responses to drugs were studied. It has been found that the hypertension in patients having HR above 80 b.p.m. has a better response to atenolol. On the other hand, in patients having HR below 70 b.p.m. the response is better to chlorthalidone. In those patients with HR between 71 and 79 a similar response to both drugs is observed, nevertheless the decrease of the diastolic pressure is significantly bigger with atenolol. We arrive at the conclusion that when the HR is above 70 b.p.m. and especially above 80 b.p.m., better results are obtained using atenolol than chlorthalidone.