We investigated whether right atrial (RA) volume could be used to predict the recurrence of atrial fibrillation (AF) after pulmonary vein catheter ablation (CA). We evaluated 65 patients with ...paroxysmal AF (mean age, 60+10 years, 81.5% male) and normal volunteers (57 ± 14 years, 41.7% male). Sixty-four-slice multi-detector computed tomography was performed for left atrial (LA) and RA volume estimations before CA. The recurrence of AF was assessed for 6 months after the ablation. Both left and right atrial volumes were larger in the AF patients than the normal volunteers (LA: 99.7+33.2ml vs. 59.7+17.4ml; RA: 82.9+35.7ml vs. 43.9+12ml; P<0.0001 for both). A total of 16 patients (24.6%) showed recurrence of AF, involving both atrial volumes (LA: 125.8+36.9ml in patients AF recurrence vs. 91.1+27.1ml in 49 patients with no recurrence, P = 0.001; RA: 117.5+ 40.9ml vs. 71.6+25.5ml, P<0.0001). The sensitivity with large LA volumes (>100ml) for predicting the recurrence of AF was 81.3% in 13 of 16 patients with AF recurrence, and the specificity was 69.4% in 34 of 49 patients without recurrence. The sensitivity with large RA volumes (>87ml) was 81.3% in 13 of 16 patients with AF recurrence, and the specificity was 75.5% in 37 of 49 patients without recurrence. RA volume is a useful predictor of the recurrence of AF, similar to LA volume.
The corticocortical afferents innervating the prefrontal cortex in the monkey were studied by means of the retrograde axonal transport of horseradish peroxidase. After injection of small amounts ...(0.3-0.5 microliter) of this enzyme into various parts of the prefrontal cortex, many labeled neurons (mostly pyramids of 15-25 microns in diameter) were found in various cortical regions of the ipsilateral hemisphere. A small part of the prefrontal cortex received fibers from other parts of the same cortex. For example, area 8 receives many fibers from both the rostral part of area 9 and a small area adjacent to the inferior branch of the arcuate sulcus. On the other hand, area 9 in the inferior prefrontal convexity receives fibers from localized parts of areas 8 and 9 in the dorsolateral convexity as well as from area 6. It is also apparent that association connections from the dorsolateral to the inferior convexity are stronger than those going in the opposite direction. The prefrontal afferents from other cortical regions include many fibers originating from the posterior association cortex as well as some fibers arising in the cingulate and orbital gyri. The prefrontal cortex does not receive direct corticocortical fibers from the motor and "primary" sensory cortices. There is a topographic pattern in the prefrontal projections from the cortical walls (STs area) surrounding the superior temporal sulcus. Thus, the caudal half of the STs area projects to area 8 and a small adjacent part of area 9. The dorsal wall of the rostral half of the STs area projects to areas 9-12, the fundus to the inferior convexity, and the ventral wall only to the caudal part of the convexity. Projections from the circumjacent association cortex of the STs area to the prefrontal cortex as well as to the STs area are likewise found to be topographically organized. This suggests that certain parts of the posterior association cortex projecting to particular areas of the prefrontal cortex, also send fibers to those parts of the STs area which project to the same prefrontal areas.
Corticocortical afferents to both cortical walls of the cat middle suprasylvian sulcus (MSs area) were investigated by means of retrograde axonal transport of horseradish peroxidase (HRP). the visual ...cortex (V-I and V-II) projects to the medial wall of the MSs, the projection from V-II being heavier. The auditory cortex (A-I, A-II,. and Ep), including cortical walls of the dorsal part of the anterior and posterior ectosylvian sulci, sends fibers to the lateral wall of the MSs. Connections from the first auditory area (A-I) are heavier than from the second (A-II). In the rostral part of the MSs, both the medial and lateral walls receive fibers from the somatosensory (S-I and S-II) cortex. A larger number of association fibers appear to arise from S-II than S-I. Although the MSs as a whole apparently receives various kinds of sensory inputs, there seems to be a parcellation of th MSs area such that the areas receiving cortical association fibers from the visual, auditory, or somatosensory cortical areas also receive thalamic projections from those parts of the thalamus receiving sensory connections of the same modality. The cells of origin of the association fibers were mostly pyramidal, the majority located in layer III (e.g., 80% in the visual cortex and 74% in the auditory cortex), some in layer V, and a few in other layers. Most (76-79%) of the labeled cell bodies were of 15-20 micrometer diameter. Smaller (8-15 micrometer) and larger (20-26 micrometer) cells constituted less than 15% in each case. The mean diameters were 17.0 +/- 2.8 (SD) in the visual cortex and 17.7 +/- 3.2 micrometer (SD) in the auditory cortex.
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