Adenosine myocardial SPECT--its efficacy and safety and correlation with coronary angiogram.

OBJECTIVE: The aim of this study was to determine the safety and efficacy of adenosine Tc99m sestamibi myocardial perfusion study under controlled conditions and to correlate the adenosine Tc99m sestamibi perfusion defects and the coronary angiography in patients investigated for coronary artery disease. METHODS: This prospective study included 122 consecutive patients who underwent adenosine Tc99m sestamibi single photon emission computed tomography (SPECT) myocardial perfusion study. Seventy two patients had coronary angiographic correlation. All the patients who were referred by the cardiologists for stress myocardial perfusion scan who could not be stressed physiologically for one reason or the other were included in the study. RESULTS: Among the coronary angiography group the overall sensitivity, specificity, positive predictive value and negative predictive value of adenosine Tc99m sestamibi single photon emission computed tomography myocardial perfusion study for detecting significant coronary obstruction (diameter > or = 50%) were 94.4%, 79%, 85% and 92% respectively. The side effects were transient and required no treatment. CONCLUSION: We conclude adenosine Tc99m sestamibi single photon emission computed tomogram myocardial perfusion study is a reliable test with high sensitivity and specificity for the detection of coronary artery disease.

Usefulness of concomitant nitrate administration for the enhancement of viability detection with myocardial perfusion imaging.

Myocardial viability assessment is crucial in the evaluation of patients who had prior myocardial infarction for revascularisation procedures. Conventional methods include nuclear myocardial perfusion imaging, dobutamine stress echocardiography and positron emission tomography. Utility of nitrate in assessment of viability was assessed. Twenty-five patients with prior myocardial infarction underwent 99mTc-sestamibi single photon emission computed tomography protocol of stress, rest and post 5 mg sublingual isorbide dinitrate. The mean age of the patients was 51.28 years. Eight (32%) had reduction in perfusion defect and increased tracer uptake following nitrate administration. It is concluded that addition of nitrate adds to utility of conventional perfusion imaging in the assessment of myocardial viability.