Author + information
- Ertan Vuruşkan1,
- İdris Ardıç2,
- Emre Akkaya1,
- Cemil Zencir3,
- Mustafa Çetin3,
- Murat Akkoyun2 and
- Gürkan Acar2
Heart rate recovery after exercise is a function of vagal reactivation, and its impairment is an independent prognostic indicator for cardiovascular and all-cause mortality. The aim of our study was to evaluate heart rate recovery in patients with coronary slow flow phenomenon (CSFP).
The study population included 43 patients with CSFP (29 men; mean age, 50.0±10.5 years) and 30 control subjects (18 men; mean age, 53.7±11.3 years) with normal coronary arteries on angiography. Basal electrocardiography, echocardiography, and treadmill exercise testing were performed in all patients and control participants. Coronary flow was quantified using the corrected TIMI frame count (TFC) method. The heart rate recovery index was defined as the reduction in the heart rate from the rate at peak exercise to the rate 1st-minute (HRR1), 2nd-minute (HRR2), 3rd-minute (HRR3) and 5th-minute (HRR5) after the cessation of exercise stress testing.
There are significant differences in HRR1 and HRR2 indices between patients with CSFP and control group (28.8±6.4 versus 34.2±7.1; p=0.001 and 48.5±11.5 versus 53.9±10.5; p=0.04, respectively). The TFCs for all the epicardial coronary arteries and the mean TFC were significantly higher in the CSFP group (p<0.01). There were also remarkably negative correlations between the mean TFC and HRR1 (r=-0.27, p=0.02), and HRR2 (r=-0.24, p=0.04).
The heart rate recovery index impaired in patients with CSFP compared to control subjects. When the prognostic significance of the heart rate recovery index is considered, a useful, simple, and noninvasive test may be clinically helpful in the recognition of high-risk patients with CSFP.