Yasuhiko Ohno

Clinical Significance of QRS Duration During Ventricular Pacing

To clarify the clinical significance of an abnormally prolonged paced QRS duration, we studied 114 patients who had undergone pacing for atrioventricular block (AVB). Patients were divided into two groups: group I consisted of 29 patients with at least one paced QRS duration ≥ 180 msec during the follow‐up period; group II consisted of 85 patients with paced QRS durations < 180 msec. The clinical background, QRS complexes before pacing, and the echocardiographic findings were assessed. Males (P < 0.05), those with H‐V block (P< 0.05) and a wider QRS complex of conducted and escape beats (both P < 0.01) were dominant in group I. The incidence of underlying heart disease was greater in group I than in group II (83% vs 32%, P < 0.01). Reduced left ventricular ejection fraction (LVEF) and increased left ventricular end‐diastolic dimension (LVDd) were more prominent in group I than in group II (LVEF 0.49 ± 0.17 vs 0.68 ± 0.10, P < 0.01, LVDd 57.1 ± 7.9 mm vs 48.5 ± 5.6 mm, P < 0.01). The paced QRS duration correlated with LVEF (r = ‐0.61) and LVDd (r = 0.81). A paced QRS duration ≥ 180 msec was sensitive and specific for a LVEF < 0.5 (83.3% and 85.2%) and LVDd ≥ 60 mm (100% and 81.4%). We conclude that patients with a prolonged paced QRS duration have more serious heart disease, and the paced QRS duration can be a useful indicator of impaired LV function.

Carcinosarcoma of the esophagus characterized by myoepithelial and ductal differentiations

We report a case of carcinosarcoma of the esophagus characterized by ductal and myoepithelial differentiation. A 61‐year‐old man was operated on for a polypoid tumor of the distal esophagus. Histologically, this tumor was composed of ductal structures and sarcomatous spindle cells surrounding the ducts at the central area of the tumor. The tumor was also composed of squamous cell and basaloid carcinoma in the periphery. Immunohistochemically, a few spindle cells surrounding the ductal structures showed immunopositivity for α‐smooth muscle actin and S‐100 protein. Electron microscopy revealed that the spindle cells had tonofilament and pinocytic vesicles in the cytoplasm, and basal lamina adjacent to the cytoplasmic membrane. Both of the results strongly supported the suggestion that the spindle cells may be myoepithelial cells. Basaloid carcinoma showed a gradual transition to chondrosarcomatous cells producing the matrix, which had both immunopositivities for S‐100 protein and cytokeratin. Therefore, chondrosarcomatous cells may be derived from carcinoma cells. The histogenesis of this tumor may be associated with a totipotential stem cell of esophageal mucosa, which has the potential to differentiate into squamous cells, ductal cells or myoepithelial cells.

Laterally spreading tumor: clinicopathological study in comparison with the depressed type of colorectal tumor.

Aim: To evaluate the difference between laterally spreading colorectal tumors (LSTs) with depression and depressed‐type colorectal tumors.

Gender-related differences on signal-averaged electrocardiograms in healthy subjects

Abstract In conclusion, filtered QRS duration in time-domain analysis of SAEs was influenced by gender and body characteristics in healthy subjects; however, the parameters in spectral turbulence analysis were not.

VDD Pacing with a Previously Implanted Single Lead System

Three patients who had undergone implantation of a rate modulated, afrial sensitive RS4 pacemaker, with a single orthogonal lead underwent replacement of a depleted unit with a DDD pulse generator, reusing the original lead with an adapter that allowed conversion of the bipolar atrial electrode into unipolar configuration. The mean atrial electrogram amplitude was 1,8 mV and no significant atrial sensing defects were found during Holler monitoring. As the RS4 pulse generator is no longer available, continued VDD pacing is possible by replacing it with a DDD pulse generator using the previously implanted single lead system.

Usefulness of computed tomography with air insufflation of the stomach prior to percutaneous endoscopic gastrostomy procedure

We examined the results of computed tomography (CT) with and without air insufflation of the stomach prior to performing percutaneous endoscopic gastrostomy (PEG). We retrospectively analyzed 366 patients who underwent PEG. CT images obtained with and without air insufflation were examined for the presence or absence of contact between the gastric anterior wall and abdominal wall. PEG outcome based on CT findings was also examined. CT with and without air insufflation was performed in 272 and 94 patients, respectively. Contact between the gastric anterior wall and abdominal wall was shown in 254 (93.4%) with and 45 (47.9%) without air insufflation, all of whom underwent a successful PEG procedure. In patients without contact between the gastric anterior wall and abdominal wall, PEG was not successful in 3 of 49 (6.1%) examined by CT without and 6 of 18 (33.3%) examined with air insufflation (p = 0.004). Values for diagnostic accuracy for contact between the gastric anterior wall and abdominal wall shown by CT with and without air insufflation in successful PEG cases were 0.96 and 0.51, respectively. In conclusion, CT with air insufflation more often revealed contact between the gastric anterior wall and abdominal wall as compared to CT without air insufflation, which may help to predict PEG procedure success.

Intra-His Bundle Block Corresponds with Interruption of the Branching Portion of the His Bundle

We compared His‐bundle electrograms with pathological findings of the atrioventricular conduction system in four patients with complete atrioventricular intra‐His block with narrow QRS complexes on ECG. Split His electrograms were recorded at the time of electrophysiological study. The patients died from noncardiac causes at 10 days, 1 year, 4 years, and 9 years, respectively, after the pacemaker implantation. Serial sections through the atrioventricular conduction system revealed strictly localized more than 50% reduction of conducting cells replaced by fibrosis at the branching portion of His bundle. The proximal portions of the bundle branches also exhibited decrease of the conducting cells showing a rough positive relation with the patients age. Therefore, we considered that the H1 spikes seen on His‐bundle electrograms originated from the penetrating portion of His, which was virtually intact in our cases, and that the H2 spikes originated from the right side of the distal branching portion of His.