Why Not All Hypertensive Patients Are Tachycardic at Rest?

Background: The importance of increased resting heart rate in hypertensive patients was highlighted in the European Society of Hypertension statement on the identification and management of hypertensive patient with elevated heart rate. Methods: Review of the available literature. Results: Increased heart rate is an independent predictor of cardiovascular morbidity and mortality even after adjustment for other conventional cardiovascular risk factors. Resting heart rate is correlated with blood pressure and prospectively related to the development of hypertension, as shown in numerous general population and hypertensive cohorts. Patients with hypertension may be characterized by increased sympathetic activation, and increased heart rate is considered a simple marker of increased sympathetic nervous activity. The definition of tachycardia is debatable as in clinical practice, tachycardia is generally defined as resting heart rate over 100 beats per minute (bpm) but this definition does not take into account epidemiological data and risk related to increased heart rate. Available evidence suggests that a lower threshold defining an increased resting heart rate should be adopted. In large hypertensive cohorts, approximately one third of the studied subjects had resting heart rate above 80-85 bpm and many of these patients had features of the metabolic/insulin resistance syndrome. Furthermore, the prevalence of hypertension increases with age and the hemodynamic pattern of hypertension in older subjects is not characterized by increased heart rate. Conclusions: These reasons, in addition to the fact that heart rate is variable and depends on multiple factors, may explain why not all patients with hypertension are tachycardic at rest.