Objectives:

Nondipping status; probably a result of sympathetic hyperacitivity; is clinically associated with poor prognosis. In this study we aimed to evaluate the variation of daytime and nighttime heart rate among dipper and nondipper patients probably due to sympathetic hyperactivity.

Material and Method:

116 patients were enrolled and performed 24 hour ambulatory blood pressure monitoring. 24-hour daytime and nighttime systolic and diastolic blood pressures and heart rates were compared between the dipper and non dipper hypertensive patients. Statistical analysis was performed by Independent Samples t test using SPSS 11.0 for Windows.

Results:

Daytime heart rates were higher in nondipper patients than dipper patients (78,3±9 vs 75,2±9, p=0.1>0.05), but the difference was not statistically significant. Also nighttime heart rates were significantly higher in non dipper patients (65,9±8,7 vs 61,7±7,8, p=0.02<0.05). Nighttime heart rate dipping is significantly lower in nondipper patients (%14.2±6.1 vs %17.8±5.9 p<0.05).

Conclusion:

Increased heart rates of daytime and nighttime period in nondipper patients are clinical finding of sympathetic hyperactivity which was accounted for nondipping. Since nondipping status is closely associated increased risk for cardiovascular events, effective treatment of nondipper patients and modifications in drug therapy may reduce cardiovascular morbidity and mortality.

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