Case history: a 76-year-old African-American female presented to a community hospital with complaints of chest pain. Her medical history was significant for hypertension, gastroesophageal reflux disease (GERD), hyperlipidemia, and bipolar disorder. On arrival at the emergency department, electrocardiogram showed acute inferior wall myocardial infarction (MI). The patient received thrombolytic therapy with tenecteplase (TNKase™) with successful reperfusion. On arrival at our hospital, the patient denied any chest pain and her electrocardiogram showed sinus bradycardia with small Q-waves in the inferior leads II, III, and AVF (see Figure 1). She was treated with aspirin, heparin, lisinopril, simvastatin, and clopidogrel. Beta-blocker was not started as the patient was having bradycardia. The patient was scheduled to undergo myocardial perfusion scan 48 hours following her uncomplicated inferior wall MI. Figure 1 Initial Electrocardiogram Showing Q-waves in the Inferior Leads At rest, the patient received 12.0mCi of technetium 99msestamibi. Seventy-five minutes later, rest myocardial perfusion images were obtained by non-gated single photon emission computed tomography (SPECT). Then she received adenosine infusion at 140µg/kg/minute for six minutes. Blood pressure and 12-lead electrocardiogram were obtained every minute and the patient’s symptoms were recorded. Resting heart rate was 67. Heart rate three minutes into the adenosine infusion was 73, and heart rate six minutes into the adenosine infusion was 85. Resting blood pressure was 152/69. Blood pressure three minutes into the adenosine infusion was 128/54, and blood pressure six minutes into the adenosine infusion was 70/47. Resting electrocardiogram showed normal sinus rhythm, small inferior Q-waves, and ST–T changes. There was an additional 1–2mm ST segment depression in the electrocardiographic leads I, AVL, and V2, plus 1–3mm additional ST segment elevation was noted in II, III, and AVF during and up to three minutes-post adenosine infusion (see Figure 2). There were occasional premature ventricular complexes and premature atrial complexes before, during, and post-adenosine infusion. The patient did not report chest pain during or after adenosine infusion. Figure 2 Electrocardiogram Obtained During Adenosine Infusion Showing ST Segment Elevation in the Inferior Leads Three minutes into the adenosine infusion, 44mCi of technetium 99m sestamibi was injected intravenously. One hour and 50 minutes later, the stress (adenosine) myocardial perfusion images were obtained by gated SPECT. SPECT images were acquired with a dual-head gamma camera using the step-and-shoot detector rotation, obtaining 32 projections over 180° arcs (45° right anterior oblique to 45° left posterior oblique). The camera was equipped with a low-energy, high-resolution collimator. Rest and stress images were acquired with a 20% window centered over the 140KeV photo peak. Gated acquisitions were obtained using eight frames per cardiac cycle with a 40% acceptance window. Acquisition times were 40 seconds per projection. The summed projection data sets were filtered with a butterworth filter (order 5 cut-off 0.33). Short-, vertical-, long-, and horizontal-axis images were evaluated for transient, partially reversible, and fixed perfusion defects. The rest and stress (adenosine) myocardial perfusion images revealed normal-sized left ventricle and mild to moderate transient myocardial perfusion defect (mild to moderate ischemia) superimposed on mild fixed myocardial perfusion defect (superimposed on mild scar) involving the inferior, inferoapex, and inferolateral wall of the left ventricle (see Figure 3). There were hypokinetic inferior, inferoapex, and inferolateral walls of the left ventricle, with resting global left ventricular ejection fraction (LVEF) of 40%. The right ventricle was normal in size and function. Figure 3 Stress Myocardial Perfusion Polar Map Depicting Flow Defect in the Region of the Right Coronary Artery Following the adenosine myocardial perfusion scanning, the patient underwent cardiac catheterization. Cardiac catheterization showed normal left main, left anterior descending, and circumflex arteries. The right coronary artery showed a 75% stenosis in the mid segment (see Figure 4). The patient had a 3.5×16mm stent deployed without any complications. Her post-procedure course in the hospital was uneventful and she was discharged the following day in a stable condition. Figure 4 Left Anterior Oblique View of the Right Coronary Artery