TASK DEFINITION: Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
PROBLEM: Radiofrequency applications to the posteroseptal region can ablate the atrioventricular accessory pathway residing in this area. In conjunction with the adjacent anatomic structures, however, ablative lesions which do not effectively ablate the accessory pathway could markedly alter retrograde atrial activation sequence and confound interpretation of further mapping of an accessory pathway.', 'Electrophysiologic studies, endocardial activation mapping and radiofrequency catheter ablation were undertaken in three patients with recurrent supraventricular tachycardia. Patients were initially thought to have a single posteroseptal accessory pathway; earliest ventrioatrial activation during tachycardias and during ventricular pacing was at the coronary sinus ostium, but initial radiofrequency applications were unsuccessful to ablate the pathway. After initial radiofrequency applications to the posteroseptal region, the earliest retrograde atrial activation changed to the right atrial free wall in two patients. Additional radiofrequency application to the posteroseptal area was able to ablate the single posteroseptal accessory pathway in one patient. Radiofrequency application to the right atrial free wall was required to stop tachycardia initiation in other patient. The third patient was suspected of having a slow-slow atrioventricular nodal reentry tachycardia. Radiofrequency application to the posteroseptal area changed the earliest retrograde atrial activation to the distal coronary sinus recording site, mimicking an accessory pathway at the left atrial free wall. Radiofrequency application to the anteroseptum was able to ablate the concealed accessory pathway.

SOLUTION: Does radiofrequency application to the posteroseptal region alter retrograde accessory pathway activation?

PROBLEM: Multiple intercostal recordings were supposed to get a more comprehensive view of the depolarization vector of the outflow tract ventricular arrhythmia (OT-VA), which may help to identify the OT-VA more accurately. This study was undertaken to develop a more accurate electrocardiogram (ECG) criterion for differentiating between left and right OT-VA origins.', 'We studied OT-VA with a left bundle branch block pattern and inferior axis QRS morphology in 47 patients with successful catheter ablation in the right ventricular OT (RVOT; n = 37) or aortic coronary cusp (ACC; n = 10). Superior and inferior precordial leads were taken together with the routine 12-lead ECG. The ECG during the OT-VA and during sinus beats were analyzed. Transition ratio, transition zone (TZ) index, R/S amplitude ratio, and R-wave duration ratio were measured in the regular, superior, and inferior precordial leads.', 'The combined TZ index, TZ index inferior was significantly smaller, while the V2 inferior transition ratio was significantly larger for ACC origins than RVOT origins (P < 0.05). The area under the curve for the combined TZ index by a receiver operating characteristic analysis was 0.974, which was significantly larger than other parameters. A cutoff value 0.25 predicted an ACC origin with 94% sensitivity and 100% specificity. This advantage of the parameter over others also held true for a subanalysis of OT-VAs with a lead V3 precordial transition or TZ index = 0.

SOLUTION: Does multiple Intercostal Space Electrocardiogram allow Accurate Localization of Outflow Tract Ventricular Arrhythmia Origin?

PROBLEM: The purpose of this study was to compare prenatal versus postnatal markers of congenital diaphragmatic hernia (CDH) severity at a single fetal-care center.', 'A retrospective study was performed of patients having a complete prenatal evaluation and surgical repair (n=55). Observed-to-expected lung-to-head ratio (o/eLHR), observed-to-expected total lung volume (o/eTLV), liver position (LP), a predictive dependent variable from logistic regression of o/eLHR and liver position (o/eLHR+LP), and diaphragmatic defect size per the CDH Study Group A-D classification were plotted into receiver-operating characteristics (ROC) curves. Survival and need for extracorporeal membrane oxygenation (ECMO) were primary outcomes.', 'Survival was 69%, and ECMO utilization was 56%. Distribution was 80% left-sided defects. In the survival ROC curve, the area under the curve (AUC) for o/eLHR was 0.73, o/eTLV 0.74, LP 0.73, o/eLHR+LP 0.78, and defect size 0.84 (p=0.23). The ROC curve for ECMO support showed o/eLHR had an AUC of 0.82, o/eTLV 0.89, LP 0.79, o/eLHR+LP 0.87, and defect size 0.90 (p=0.19). The AUCs were similar when only left-sided CDH was analyzed.

SOLUTION:
Do prenatal and postnatal markers of severity in congenital diaphragmatic hernia have similar prognostic ability?