Throughout 2013, 350 cases of patients with primary coronary syndrome were considered upon admission to the Emergency Room with clinical symptoms of ischemic heart disease, electrocardiographic alterations, acute retrosternal pain, dyspnea, syncope, shock, and increased cardiac enzymes, following a reported stressful event. Each patient underwent acute Coronary Angiography. The examination took place in the Catheterization Lab using a dedicated angiographic table. With the patient in a supine position, assisted in all vital functions (pulse, blood pressure, heart rhythm), a guidewire was inserted through the femoral or radial artery and advanced to the origin of the coronary arteries. Diagnostic catheters with a diameter of 5-6 French (2 mm) were guided over the wire and, under radiological control, brought to the aortic valve level. The injection of iodinated contrast medium (50/80 ml of XENETIX, 350 mg/ml Iobitridol) using an automatic injector (ACIST model with measurement of the vessel's internal pressure, using a flow of 2, volume of 6, and pressure of 600 for the left coronary artery examination, and a flow of 2, volume of 4, and pressure of 400 for the right coronary artery examination) and the use of dedicated projections allowed visualizing the coronary arteries and collateral branches. In the absence of pathologies, left ventriculography was performed to obtain information on LV function, its working capacity, and any damage from previous infarctions and myocarditis.

To perform ventriculography, a catheter with a pigtail-shaped tip was used, where multiple holes allow the contrast medium to be introduced into the ventricle in sufficient quantity to visualize it before "wash-out" (flow 15, volume 6, and pressure 800). Left ventriculography typically shows characteristic alterations of this syndrome: apical ballooning and increased contractility of basal segments with a typical reduced contractile function of the left ventricle. In 2% of the cases considered (approximately 8/9 patients), coronary arteries were intact, and left ventricular contractility was reduced. To complete the clinical-diagnostic framework, these patients underwent a cardiac scintigraphy exam with 123I-MIBG to study neuroadrenergic innervation, highlighting reduced accumulation of the radiopharmaceutical specific to neuroadrenergic termination at the cardiac level when pathological.

The radiopharmaceutical used is a ready-to-use injectable solution of Iobenguane (123I), commercially known as "AdreView"® - GE Healthcare S.r.l. - Milan. Preparation for this exam involves thyroid inhibition 24-48 hours before Iobenguane (123I) administration and continued for at least 3 days afterward with Lugol's solution or potassium perchlorate (Pertiroid 400 mg orally). Suspension of neuroleptic drugs, tricyclic antidepressants, and amphetamines is advisable, as they may result in reduced cardiac uptake of the radiopharmaceutical. A dose of 111-185 MBq (3-5 mCi) of [123I] MIBG is administered by slow intravenous injection (lasting approximately 1-5 minutes), possibly followed by the administration of a 0.9% sodium chloride solution with a volume not exceeding that injected to ensure complete use of the dose.

Static planar images are acquired at two distinct times: at 15 minutes (for the early phase) and 240 minutes (for the late phase) after tracer administration in Anterior and Left Anterior Oblique chest projections, covering the heart and upper mediastinum with a large field of view (matrix 128 x 128, for 600 seconds each), integrated with the heart/mediastinum uptake ratio evaluation through post-processing. In the early phase (within the first 15/30 minutes), a 180° SPECT study is performed, from the 45° left anterior oblique to the 45° right posterior oblique projection, using 60 or 64 projections with a 3° angular step, as for all myocardial studies, with a not too high zoom (1.3) to include the upper mediastinum in the field of view and an acquisition time of 30/40 seconds per projection. Even visual analysis alone has allowed a diagnostic judgment in many cases; however, a semi-quantitative analysis was always performed, obtained from the ratio between counts obtained on the heart and those at the upper mediastinum levels (considered as background activity). For this purpose, two irregular or rectangular ROIs were placed on both regions in each image, and an index defined as the heart/mediastinum ratio (H/M) was calculated.