en Cardiology Cardiology Original Article Original Article <span style="font-size:14px;"><span style="font-family:times new roman;"><span style="color:#0000FF;"><strong><em>Background:</em></strong></span> Chronotropic incompetence has prognostic value of all-cause and cardiovascular mortality in both patients with asymptomatic and symptomatic ischemic heart disease (IHD), regardless of traditional risk factors. The aim of this study was to investigate the relationship between chronotropic response during exercise test and the development of ventricular arrhythmias.<br> <span style="color:#0000FF;"><strong><em>Methods</em></strong><em>:</em></span> 153 patients with stable ischemic heart disease were screened and observed during the 24 months since October 2014 in a university hospital in Astana Kazakhstan. They underwent bedside electrocardiography, 24h heart rate Holter monitoring, echocardiography, exercise stress test (treadmill) for assessment of chronotropic index calculating at first contact. Holter- electrocardiography was repeated three times (at 3, 6, 12 months of follow-up period) to reveal life-threatening ventricular arrhythmias.<br> <span style="color:#0000FF;"><strong><em>Results:</em></strong> </span>The quantity of the ventricular extrasystoles was higher in the group with low chronotropic index. Low chronotropic index increased the risk of high grade ventricular extrasystoles more than two times (P=0.015); episodes of non-sustained VT more than three times (p<0.001); and episodes of sustained VT more than nine times (p<0.001).<br> <span style="color:#0000FF;"><strong><em>Conclusions:</em></strong></span> Chronotropic index less than 35.6 increases the risk for life-threatening ventricular arrhythmias in patients with stable chronicle ischemic heart disease irrespectively of severe left ventricle systolic dysfunction.</span></span><br> <p></p> Chronotropic incompetence,stable ischemic heart disease, ventricular arrhythmias, risk factor 164 170 http://caspjim.com/browse.php?a_code=A-10-568-1&slc_lang=en&sid=1 Yelena Rib tarlan186@mail.ru 100319475328460012044 100319475328460012044 No Astana Medical University, Astana, Kazakhstan Gulnar Zhussupova gulnar.zh1@gmail.com 100319475328460012045 100319475328460012045 No Astana Medical University, Astana, Kazakhstan Gaukhar Igimbayeva igt_tgt@mail.ru 100319475328460012046 100319475328460012046 No Karaganda State Medical University, Karaganda, Kazakhstan Ayan Abdrakhmanov ayan-3@mail.ru 100319475328460012047 100319475328460012047 No Department of Interventional Arrhythmology, National Research Center for Cardiac Surgery, Astana, Kazakhstan Seyedfarzad Jalali sfjalali42@yahoo.com 100319475328460012048 100319475328460012048 Yes Department of cardiology, Babol University of Medical Sciences, Babol, Iran