The incidence of nondipping state in normotensive patients with coronary slow flow and its relationship with prognosis

Abstract

Objectives: We investigated the frequency of nondipping pattern, which is thought to be related with increased sympathetic activity, and its influence on the pathogenesis and prognosis of patients with coronary slow flow. Study design: The study included 51 normotensive patients (22 females, 29 males; mean age 54 years) in whom coronary slow flow (CSF) was diagnosed by coronary angiography and TIMI (thrombolysis in myocardial infarction) frame count. Venous blood samples were obtained at the same hours of the day to determine noradrenaline and adrenaline levels and 24-hour ambulatory blood pressure monitoring was performed. At least 10% of sleep-related nocturnal decrease in systolic and diastolic pressures was accepted as dipping, while decreases below 10% were defined as nondipping. The results were compared with those of 44 subjects (18 females, 26 males; mean age 55 years) with normal coronary flow. Results: The number of nondippers compared to dippers was significantly higher in the CSF group (n=35, 68.6% vs n=16, 31.4%, p<0.001), and vice versa in the control group (n=3, 6.8% vs n=41, 93.2%, p<0.0001). Compared to controls, CSF was significantly associated with increased plasma noradrenaline (127.9 ng/ml vs 79.3 ng/ml, p<0.0001) and adrenaline (63.9 ng/ml vs 44.7 ng/ml, p<0.001) levels (p<0.001). A positive correlation was found between TIMI frame counts and noradrenaline (r=0.421, p=0.012) and adrenaline (r=0.445, p=0.008) levels in the CSF group. Nondippers in the CSF group exhibited significantly higher noradrenaline (p<0.01) and adrenaline (p<0.05) levels, existence of slow flow in three coronary arteries (p<0.01), and TIMI frame counts (p<0.05) compared to dippers. During a four-year follow-up, chest pain like that of unstable angina, recurrent chest pain, malignant ventricular arrhythmias, and sudden cardiac death were more frequently encountered in nondippers than in dippers. Conclusion: Nondipping pattern seen in patients with CSF is associated with sympathetic hyperactivity and poor prognosis.