Mitral annular calcification (MAC) is a chronic, degenerative disease characterized by accumulation of calcium and lipid in the fibrous ring of the mitral valve. Heart rate recovery index (HRR) calculated after treadmill exercise test is a predictor of autonomic dysfunction and cardiovascular mortality. The aim of this study was to investigate the relationship between MAC and HRR parameters. 64 patients with MAC (mean age 54.9±5.8, 40 males) and 44 healthy controls (mean age 55.1±6.5, 28 males) were included in the study. All subjects in the MAC group and control group underwent basal 12-lead electrocardiography, echocardiography, and treadmill exercise test at a target rate determined by age. HRR indices were calculated from the maximal heart rate by subtracting the heart rate at the 1st, 2nd and 3rd minutes of the recovery period. Baseline demographic and laboratory data were similar in both groups. Compared with healthy controls, individuals with MAC had decreased HRR at 1 (HRR1), 2 (HRR2), and 3 (HRR3) minutes [16.9 ± 4.5 vs. 19.2 ± 3.9, p = 0.009; 33.9 ± 4.6. 36.2 ± 5.1, p = 0.019; 49.6 ± 7.1. 52.4 ± 6.1, p = 0.035; respectively]. These results show that heart rate recovery after exercise is impaired in individuals with MAC. Given the independent prognostic value of HRR, these findings can be evaluated in terms of symptomology of autonomic dysfunction in people with MAC. Because HRR is a simple and inexpensive method, it may be useful in identifying high-risk patients, especially in individuals with MAC.
Key words: Heart rate recovery, Mitral annular calcification, Treadmill exercise test
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