Ambulatory monitoring of heart rate and blood pressure during the first week after smoking cessation.

To investigate the timecourse of cardiovascular changes immediately after smoking cessation, 16 subjects wore ambulatory monitors on alternate days during a 1-week residential smoking cessation program. Heart rate was significantly elevated at the time of cessation, then declined steadily until 6 h after cessation, when it reached the level of subsequent nonsmoking days. Systolic and diastolic blood pressures were elevated to a lesser degree for the same period after cessation. The timing of the decline in heart rate and blood pressure was coincident with the timing of an increase in withdrawal symptoms and has implications for laboratory and epidemiologic studies.