The Relationship Between GATED Myocardial Perfusion SPECT Findings and Heart Rate Recovery After Exercise Test

Abstract

<p><strong>Objective: </strong>Coronary artery disease has been thought that autonomic nervous system dysfunction especially increased sympathetic tonus and relatively decreased parasympathetic activity is related to coronary artery disease. Abnormal heart rate recovery after exercise test, is a simple available parameter, that reflects autonomic nervous system disfunction. GATED myocardial perfusion SPECT is used in the diagnosis and prognosis of coronary artery disease. In this study we compared heart rate recovery with myocardial perfusion scintigraphy findings.</p><p><strong>Methods:</strong> In our study there were 50 subjects (27 female, 23 male). Multiple lineer regression analysis was used to determine relationship between heart rate recovery and GATED myocardial perfusion SPECT parameters, age, gender, and history.</p><p><strong>Results:</strong> Multiple lineer regresion revealed strong independent negative assosiation between heart rate recovery and myocardial defect severity on stress images (β= -0.957; SE= 0.650; p= 0.043). Age was also an independent predictor of heart rate recovery with negative assosiation (β= -0.473; SE= 0.250; p= 0.022). Correlation coefficient (R) and R square (R<sup>2</sup>) of the model were 0.604, and 0.365 respectively.</p><strong>Conclusion:</strong> On stresss protocol, myocardial damage is more severe in patients who have decreased heart rate recovery. Since the severity of myocardial damage on stresss is a strong predictor of cardiac events and prognosis, heart rate recovery was also have prognostic value on future cardiac events.