technetium-tc-99m-exametazime and Atrial-Fibrillation

The aim of our study was to determine if ablation and pacing improved brain perfusion (BP) and cognitive function (CF) in patients with medically refractory rapidly conducted atrial fibrillation (Med Refr RCAF).. The study included 17 patients with Med Refr RCAF (average age 55.3 ± 4.5 years). All patients underwent brain single photon emission computed tomography scanning with (99m) Tc-hexamethylpropylene amine oxime and comprehensive neuropsychological testing before and after 3 months following pacemaker implantation. The BP was significantly lower in all regions in patients with Med Refr RCAF compared with the control group. The greatest BP decrease was revealed in the inferior frontal (P = 0.002) and posterior parietal (P = 0.024) brain regions. These patients showed cognitive deficit in 94%. There was a direct correlation between BP and CF parameters. Ablation followed by pacemaker implantation had a positive effect on BP and CF in all patients with Med Refr RCAF. Thus, BP increased in the right inferior frontal (P = 0.01), in the left superior frontal (P = 0.007), and in the left temporal (P = 0.005) cortex. These patients demonstrated improvements in immediate and delayed verbal memory, immediate and delayed visual memory, abstract mentation, attention, psychomotor speed, as well as in learning.. Patients with atrial fibrillation and rapid ventricular rates refractory to medical treatment have marked signs of brain hypoperfusion and impaired CF. Ablation and pacing improve left ventricular systolic function, thereby increasing BP and improving CF.

Topics: Atrial Fibrillation; Atrioventricular Node; Attention; Brain; Catheter Ablation; Cognition; Female; Humans; Male; Memory; Middle Aged; Neuropsychological Tests; Pacemaker, Artificial; Radiopharmaceuticals; Technetium Tc 99m Exametazime

A 71-year-old man with atrial fibrillation suddenly had an embolism in the right middle cerebral artery. Single-photon emission CT was performed 4 hours after the onset of stroke and revealed markedly elevated 99mTc-hexamethylpropyleneamine oxime (HMPAO) uptake in the right frontotemporoparietal region. This area of HMPAO hyperfixation corresponded to the area of infarction, as determined by CT and MR. Our findings showed that HMPAO single-photon emission CT overestimated reflow hyperemia after reperfusion in the acute stage of embolic stroke, as it does in the subacute stage.

Topics: Acute Disease; Aged; Atrial Fibrillation; Frontal Lobe; Humans; Intracranial Embolism and Thrombosis; Magnetic Resonance Imaging; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Temporal Lobe; Thrombolytic Therapy; Tissue Plasminogen Activator; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed