Can an increase in the pulmonary vein volume measured by three dimensional computed tomography predict the presence of atrial fibrillation?

BACKGROUND: Left atrial (LA) dilation is associated with morbidity of atrial fibrillation (AF). However, little is known about pulmonary vein (PV) dilation. PURPOSE: We investigated the PV volume in the patients with AF. METHODS AND RESULTS: We performed 3dimensional computed tomography (3DCT) in 155 patients and divided them into three groups: 19 patients without AF (non-AF group, mean age 66 ± 12 years), 50 with paroxysmal AF (PAF group, mean age 67 ± 8 years) and 24 with persistent AF (PeAF group, mean age 64 ± 10 years). The absence of AF was diagnosed in patients with a cardiac implantable electronic device for at least 1 year (mean: 59 ± 37 months). We determined the PV volume as the total volume from the orifice to the first branch of each PV. According to the echocardiographic data, the LA dimension (LAD) and LA volume index (LAVI) were largest in the PeAF group followed by the PAF and non-AF group. According to the morphometric data obtained on 3D-CT, the PV volume was similar in PeAF and PAF groups but significantly smaller in the non-AF group (median value: 24 vs 21 vs 14 mL, respectively). According to the receiver operating characteristic curve analysis, the area under the curve for the PV volume in the presence of AF was 0.80, and the optimum cut-off value was 17 mL (sensitivity 74%, specificity 80%). CONCLUSION: The PV volume might be useful for predicting the presence of AF before increases in the LAD and LAVI on echocardiography.

Cardiac Sarcoidosis Mimicking Septal Tumor with Intermittent Complete Atrioventricular Block.

A 52-year-old woman with intermittent complete atrioventricular (AV) block detected on exercise was admitted to the hospital. Echocardiography revealed lesions on the right ventricular side of the interventricular septum and free wall of the basal inferolateral area. Gadolinium-enhanced cardiovascular magnetic resonance (CMR) imaging revealed the mass and wall thickening at the same locations with late gadolinium enhancement (LGE). Focal uptake at the septal lesion was detected using 67Ga scintigraphy. Focal on diffuse intense uptake in the lesions was observed on Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging. Whole-body CT and laboratory evaluations uncovered no signs of malignant tumors in other organs. Ophthalmologic evaluation revealed ophthalmologic sarcoidosis. Although the result of endomyocardial biopsy was negative, the presence of cardiac sarcoidosis was strongly suggested on the basis of the new Japanese guidelines published in 2017. AV conduction disturbance and tracer accumulation on 67Ga scintigraphy completely disappeared after 2 weeks of steroid therapy. The size of mass, inferolateral wall thickness in echocardiography and CMR, and standardized uptake value (SUV) of the masses on 18F-FDG PET also decreased over time.

Mechanism of decrease in the atrial potential after implantation of a single-lead VDD pacemaker: atrial histological changes after implantation of a VDD pacemaker lead in dogs.

The single-lead VDD pacemaker system (VDDPS) enables atrial synchronous ventricular pacing with only one lead in patients with an atrioventricular block. There are some cases in which the atrial potential decreases after implantation of a VDDPS, making physiological pacing difficult. The mechanism of this decrease has not been elucidated yet. To elucidate the possible relationship between the decrease of the atrial potential after implantation of a VDDPS and histopathological changes of the atrium. We implanted a VDDPS from the jugular vein under anesthesia in 10 adult dogs. The tip of the pacing lead was fixed in the right ventricular apex of the heart under fluoroscopic guidance. Then, the lead was ligated and fixed to the jugular vein at a point where a favorable atrial potential was obtained. The end of the lead was passed from the neck to the back subcutaneously; then pulled outside and fixed there to measure the atrial potential. The atrial potential was measured using a pacing system analyzer under anesthesia on days 3 (n = 9) and 7 (n = 8), as well as on weeks 2 (n = 6), 3 (n = 4), and 4 (n = 3), after the implantation. The heart was removed from the dogs on day 3 (n = 2), day 7 (n = 2), week 2 (n = 2), and week 4 (n = 4) to examine the atrial histological findings. The atrial potential was 2.7 +/- 0.7 mV at the time of the implantation, 1.7 +/- 1.1 mV (P < 0.05) on day 3, and 1.7 +/- 0.7 mV on week 4 after the implantation. Macroscopically, the pacemaker lead was covered with thrombus, and adhered to the atrial wall in 80% of animals. Microscopically, the endocardium was hypertrophic due to fibrous tissue; besides RBC extravasation, inflammatory cells infiltration and degeneration of myocardial cells, were observed under the endocardium. Inflammatory changes developed in the atrial wall after implantation of the VDDPS, and this seemed to be one of the mechanisms for the decrease of the atrial potential of the VDDPS.

Orexin-1 receptor immunoreactivity in chemically identified target neurons in the rat hypothalamus.

Immunohistochemistry and Western blotting were used to determine the distribution of orexin receptors in the rat brain. Strong orexin receptor 1 (OX1R) immunoreactivity was detected in the hypothalamus including the arcuate, ventromedial, and tuberomammillary nuclei that are involved in feeding regulation. The neuropeptide Y- and proopiomelanocortin-containing neurons of the arcuate nucleus, which act to stimulate or to inhibit feeding, respectively, displayed intense OX1R immunoreactivity by double immunostaining. Western blotting analysis yielded a 50-kDa major band of OX1R.