Objectives: A mild decrease in blood pressure and increase in heart rate (HR) are considered normal hemodynamic responses to dipyridamole. In this study, we tried to investigate the relation between the responses of heart rate to dipyridamole stress test with left ventricular perfusion and function data obtained from myocardial perfusion scintigraphy. Methods: Forty consecutive patients undergoing dipyridamole stress Technetium - 99m (Tc 99m) Sesta MIBI gated myocardial perfusion single photon emission computed tomography (SPECT) at the nuclear cardiology Lab of the cardiology department of the main university hospital of Alexandria University were prospectively enrolled from July 2013 for 6 months. Dipyridamole was infused over 4 min and TC 99m Sesta MIBI was injected 2 min after the end of infusion. Blunted heart rate response to dipyridamole considered if the HR ratio (peak HR/rest HR) was 1.20 or less. Summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for myocardial perfusion in addition to total perfusion defect TPD, ejection fraction and territory of perfusion defect were obtained.Patients were grouped according to HR response and groups were compared. A logistic regression analysis was used to determine independent predictors of reduced HR response. Results: Blunted heart rate response was found in 67.5 % of patients. Patients with abnormal heart rate response were more frequently had a history of diabetes mellitus (X2 = 4.01). High baseline heart rate (t = 1.9), low post stress ejection fraction (t = 3.21) and perfusion defect in left circumflex territory (X 2 = 4.01) was found in blunted heart rate response group more than normal group. Conclusion: Severe perfusion defectis associated with blunted heart rate group as left ventricular dysfunction is associated with reduced chronotropic response to dipyridamole.Diabetes mellitus and cardiac autonomic neuropathy may reflect higher baseline heart rate.