Paced P-wave morphology templates to guide atrial tachycardia localization: A derivation and validation study.

BACKGROUND: Surface ECG is a useful tool to guide mapping of focal atrial tachycardia (AT). OBJECTIVES: We aimed to construct 12-lead ECG templates for P-wave morphology (PWM) during endocardial pacing from different sites in both atria in patients with no apparent structural heart disease (derivation cohort), with the goal of creating a localization algorithm, which could subsequently be validated in a cohort of patients undergoing catheter ablation of focal AT (validation cohort). METHODS: We prospectively enrolled consecutive patients who underwent electrophysiology study, had no structural heart disease and no atrial enlargement. Atrial pacing, at twice diastolic threshold, was carried out at different anatomical sites in both atria. Paced PWM and duration were assessed. An algorithm was generated from the constructed templates of each pacing site. The algorithm was applied on a retrospective series of successfully ablated AT patients. Overall and site-specific accuracy were determined. RESULTS: Derivation cohort included 65 patients (25 men, age 37 ± 13 years). Atrial pacing was performed in 1025 sites in 61 patients (95%) in RA and in 15 patients (23%) in LA. The validation cohort included 71 patients (28 men, age 52 ± 19 years). AT were right atrial in 66.2%. The algorithm successfully predicted AT origin in 91.5% of patients (100% in LA and 87.2% in RA). It was off by one adjacent segment in the remaining 8.5%. CONCLUSIONS: A simple ECG algorithm based on paced PWM templates was highly accurate in localizing site of origin of focal AT in patients with structurally normal hearts.

Pineal cysts without hydrocephalus: microsurgical resection via an infratentorial-supracerebellar approach-surgical strategies, complications, and their avoidance.

Indications for surgery of pineal cysts without ventriculomegaly are still under debate. In view of the limited data for pineal cyst resection in the absence of hydrocephalus, and the potential risk of this approach, we have analyzed our patient cohort focusing on strategies to avoid complications according to our experience in a series of 73 pineal cyst patients. From 2003 to 2015, we reviewed our database retrospectively for all patients operated on a pineal cyst. Furthermore, we prospectively collected patients from 2016 to 2020. In summary, 73 patients with a pineal cyst were treated surgically between 2003 and 2020. All patients were operated on via a microscopic supracerebellar-infratentorial (SCIT) approach. The mean follow-up period was 26.6 months (range: 6-139 months). Seventy-three patients underwent surgery for a pineal cyst. An absence of enlarged ventricles was documented in 62 patients (51 female, 11 male, mean age 28.1 (range 4-59) years). Main presenting symptoms included headache, visual disturbances, dizziness/vertigo, nausea/emesis, and sleep disturbances. Complete cyst resection was achieved in 59/62 patients. Fifty-five of 62 (89%) patients improved after surgery with good or even excellent results according to the Chicago Chiari Outcome Scale, with complete or partial resolution of the leading symptoms. Pineal cysts resection might be an indication in certain patients for surgery even in the absence of ventriculomegaly. The high percentage of postoperative resolution of quality-of-life impairing symptoms in our series seems to justify surgery. Preoperatively, other causes of the leading symptoms have to be excluded.