[Heart rate and isolated clinical tachycardia in hypertensive patients]. / Frecuencia cardíaca y taquicardia clínica aislada en pacientes con hipertensión arterial.

BACKGROUND: There is poor information for isolated clinical tachycardia (ICT), that is to say, office tachycardia but normal ambulatory heart rate (HR). Our objective was to describe it and to know differences between hypertensive subjects with and without ICT. PATIENTS AND METHOD: Comparative study after a diagnostic intervention (ambulatory blood pressure monitoring, ABPM, SpaceLabs 90202-90207), with convenience sampling of non-treated hypertensive patients attended in primary care. We excluded subjects with heart, thyroid or lung disease. ICT were defined on the basis of office and daytime HR percentile 90 of the whole sample. RESULTS: A total of 256 subjects were included, 128 (50%) women, age 49.1 (16.1) years, with mean office blood pressure (BP) 151 (17.1)/92 (11.9) mmHg. The prevalence of ICT was 7.03% (CI 95%, 4.03-11.07) (n = 18). We didn't find any association between isolated clinical hypertension and ICT (p = 0.87). Patients with ICT have lower office and systolic night time BP, lower night time variability, higher night time BP fall, although higher 24 hours-HR and daytime-HR in comparison with non ICT hypertensive patients. In the multivariate analysis only office diastolic BP (OR, 0.93 [CI 95%, 0.87-0.98], for each mmHg increment) and office HR (OR, 1.2 [CI 95%, 1.11-1.28], for each beat for minute increment) were predictive of ICT. CONCLUSIONS: In this study 7.03% of non treated hypertensive patients present ICT, which suggest a profile of more favorable cardiovascular risk than that without ICT. Only office diastolic BP and office HR were predictive variables of ICT.