Impact of mapping points in high-density mapping of the left atrium.

PURPOSE: Currently, high-density mapping techniques are being discussed for more precise voltage mapping, lesion validation after pulmonary vein isolation (PVI) and superior left atrial tachycardia (LAT) mapping. However, the quality of high-density maps varies according to different mapping systems, multipolar catheter (MPC) types and numbers of mapping points. The aim of this study was to evaluate the impact of different numbers of mapping points in high-density mapping on validity. METHODS: From February 2016 to August 2018, 154 patients with previous PVI ablation and recurrent atrial fibrillation (AF) or left atrial tachycardia (LAT) were mapped by Orion™ multipolar catheter and Rhythmia HDx™ mapping system at our centre. Of those, 90 maps from 25 patients [11 male patients/14 female patients; age 76 ± 12 years] with 8000 to 16,000 mapping points in the primary map were collected. All maps were evaluated offline by two independent and blinded electrophysiologists regarding the following issues: (1) Is PVI observable in all veins? (2) Does voltage map cover the whole left atrium? (3) Does activation map display one or more isthmuses? The 90 maps consist of 30 maps with deactivated 24 of 64 electrodes of MPC with < 1000 mapping points (A), 30 maps with deactivated 16 of 64 electrodes of MPC and 2000 to 6000 mapping points (B) and 30 primary maps with 8000 to 16,000 mapping points (C). RESULTS: For (A), only in one map (3.3%), for (B) in 20 maps (66.7%, p < 0.05) and for (C) in 24 maps (80%) both investigators agreed with evaluable PVI in all veins. Investigators were able to assess whether the voltage map covered the whole left atrium and the same low voltage areas in (A) in 0 maps, in (B) in 16 maps (53%, p < 0.05) and in (C) in 23 maps (77%, p < 0.05). Also, investigators were able to locate the same critical isthmuses in the activation maps in (A) in 0 maps, in (B) in 2 maps (7%) and in (C) in 20 maps (67%, p < 0.05). CONCLUSIONS: In order to achieve comparable high-density maps which are verified by independent investigators, a minimum of 2000 to 6000 mapping points are required in the majority of voltage maps to evaluate PVI and low voltage areas. To define the critical isthmuses in activations maps, 8000 mapping points or more might be necessary. High-density maps with more than 8000 points increase the interrater reliability.

[How should patients with completely resected gastrointestinal stromal tumours (GIST) be followed up?]. / Welche Form der Nachsorge ist bei Patienten mit R0-resezierten gastrointestinalen Stromatumoren (GIST) sinnvoll?

UNLABELLED: Gastrointestinal stromal tumours are topical because of their uncertain biological behaviour and the potential of treatment with imatinib. In the following study we have examined which pattern of follow-up is both appropriate for detecting recurrences and cost-effective. PATIENTS AND METHODS: Between July 1997 and February 2004 we treated 43 patients diagnosed with a GIST. Patients with high risk (HR), intermediate risk (IR), or overtly malignant (OM) tumours were followed-up regularly. In 2004 we screened all patients independent of their risk of malignant disease with an ultrasound scan and endoscopy followed by endosonography. Further diagnostic procedures were carried out if necessary. RESULTS: Overall, we diagnosed recurrences in five out of 33 patients at risk (two in patients with OM, one in a patient with HR, and 2 in patients with IR according to the NIH criteria). The time period between resection of the primary tumour and recurrence ranged from 4.5 to 33 months. One of the patients with a recurrence was seen before the imatinib era, the other four were treated with imatinib mesylate. CONCLUSION: In our experience, regular follow-up should be restricted to patients with OM, HR, and IR GIST. We suggest that patients are initially seen in six months intervals for two years and annually for another three years thereafter.

[Glomus tumour of the stomach. A case report]. / Glomustumor des Magens. Ein Fallbericht.

Glomus tumours are benign neoplasms that usually arise in the skin of the extremities but have infrequently been found to occur in other sites including the stomach. We report on a 71-year-old female with non-specific epigastric pain who was diagnosed as having a small, intramural gastric tumour in addition to a cholecystolithiasis. Intraoperatively, the tumour was investigated by frozen section, but the diagnosis remained inconclusive. The ultimate histological examination showed clusters of uniform epithelioid cells surrounding wide vascular spaces. This led to the diagnosis of a glomus tumour. In a review of the recent literature,we discuss the methods and limitations of preoperative diagnostic measures.

[Abdominal ultrasound diagnosis of malignant lymphomas]. / Abdominale Ultraschalldiagnostik bei malignen Lymphomen.

The abdominal clinical staging in malignant lymphomas should be started from sonography. The size of detectable lymph nodes and focal lesions in liver and spleen (to 0.5 cm on favourable conditions of examination) reflects a comparable position of ultrasound, computed tomography and magnetic resonance imaging. The last called method seems to be advantageous only in the pelvic region. Involved lymph nodes in malignant lymphomas on the contrary to metastatic infiltration in carcinomas appear for the most part hypoechoic. The sonographic findings in liver, spleen, pancreas and kidneys infiltrated by lymphomas and other malignant diseases do not differ significantly. The involvement of gastrointestinal tract can be associated with the so called "bull's eye"-, "target"- or "pseudokidney"-sign. The endoscopic sonography could improve the preoperative staging by measuring thickened gastrointestinal wall structures and by detecting infiltrated neighbouring organs. Ultrasound-assisted needle biopsies are useful. However the favourable results reported (sensitivity, positive correlation, concordance-100%) seems to be connected with low number of cases involved. Remarkable proportion of false negative results should be expected. Laparotomy with splenectomy remains the most accurate staging method in Hodgkin's disease and non-Hodgkin's lymphomas.