Position statement on the non-invasive diagnosis of patients with ATTR pardiac amyloidosis, endorsed by the Hellenic Society of Nuclear Cardiology, for the Nuclear Medicine practitioners.

Cardiac amyloidosis is a rare condition characterized by the accumulation of abnormal proteins called amyloids in the heart tissue. These amyloids can disrupt the normal functioning of the heart and lead to a variety of symptoms and complications.

[Acetazolamide stimulation test in the preoperative assessment of cerebrovascular reserve capacity in unilateral carotid obstruction]. / Acetazolamid-Stimulationstest bei präoperativer Evaluation zerebrovaskulärer Kapazitätsreserve bei einseitiger Karotisobstruktion.

Using the 16-detector 133Xe-NaCl technique (Novo Cerebrograph) quantitative measurements of regional cerebral blood flow (rCBF) were performed in 13 patients with unilateral carotid obstruction before and after stimulation with 1 g acetazolamide. In all patients resting studies showed no significant difference in hemispheric perfusion and a 47% flow increase after acetazolamide on the side with normal carotid artery. On the obstructed side in 8 patients the hemispheric flow increased equally indicating a sufficient and adequate intracerebral collateral circulation and capacity. In 5 patients a significant redistribution of brain flow occurred with diminished increase on the occluded side. This flow pattern indicates an inadequate vasodilator response and insufficient collateral capacity. The rCBF stimulation test identifies patients with a restricted collateral capacity and these patients could benefit from a surgical treatment.

[Cerebral circulation at rest and following CO2 stimulation in patients with unilateral carotid obstruction]. / Zerebrale Durchblutung in Ruhe und nach CO2-Stimulation bei Patienten mit einseitiger Karotisobstruktion.

Using the 16-detector 133Xe-NaCl-technique (Novo Cerebrograph) quantitative measurements of regional cerebral blood flow (rCBF) were performed in 14 patients with unilateral carotis obstruction before and during stimulation with 3% CO2 inhalation. In all patients resting studies did not show any significant differences in hemispheric perfusion. In 11 patients the hemispheric blood flow increased significantly (by more than 6%) during CO2 inhalation on the side without carotis obstruction. The following results were found after 3% CO2-stimulation over the hemisphere with the obstructed carotid artery: 1) rCBF increased significantly on both sides (n = 6) indicating the sufficiency of cerebral collateral circulation; 2) a side-to-side significant difference (n = 4) with the lower perfusion on the pathological side, indicating a decreased or suspended reserve capacity; and 3) bilateral loss of cerebrovascular reactivity (n = 4) as indicator of insufficiency of cerebral collateral circulation. Asymmetry in rCBF or missing cerebrovascular reserve are indications for surgical treatment of the carotis obstruction.