Late Electrocardiographic Changes in Patients With New-Onset Left Bundle Branch Block Following Transcatheter Aortic Valve Implantation.

This study sought to determine, in patients with new-onset persistent left bundle branch block (NOP-LBBB) after transcatheter aortic valve implantation (TAVI), the incidence and factors associated with (i) LBBB recovery and (ii) permanent pacemaker implantation (PPI) at 1-year follow-up. This was a multicenter study including 153 patients (mean age: 81 ± 5 years, 56% of women) with NOP-LBBB post-TAVI (balloon-expandable valve in 112 patients). Delta PR (ΔPR) and delta QRS (ΔQRS) were defined as the difference in PR and QRS length between baseline and hospital discharge ECG, and the relative ΔPR and ΔQRS as absolute ΔPR and ΔQRS divided by baseline PR and QRS length, respectively. The patients had a clinical visit and 12-lead ECG at 1-year follow-up. LBBB recovery was observed in 50 patients (33%), and 14 patients (9%) had advanced conduction disturbances requiring PPI during the follow-up period. No clinical or ECG variables were associated with LBBB recovery, including prosthesis type (self- or balloon-expandable valve, p = 0.563), QRS width at baseline/discharge or absolute/relative ΔQRS (p >0.10 for all). The presence of atrial fibrillation at baseline (0.026), a longer PR interval at discharge (0.009), and a longer absolute and relative ΔPR (p = 0.002 and p = 0.004, respectively) were associated with an increased risk of PPI at 1-year follow-up. In conclusion, NOP-LBBB post-TAVI resolved in one-third of patients at 1-year follow-up, but no clinical or ECG variables were associated with LBBB recovery. Conversely, a nonsinus rhythm at baseline and a longer ΔPR were associated with an increased risk of PPI within the year after TAVI.

The Spinal Structure and Lung Function Relationship in an Untreated Nonambulatory Myelomeningocele Group of Patients.

INTRODUCTION: The relationship between spinal structure and respiratory function has been coined as thoracic insufficiency syndrome and is defined as the inability of the thorax to support normal respiratory function or lung growth. Little is known about what supports this relationship in untreated nonambulatory myelomeningocele patients. METHODS: A prospective cross-sectional study of nonambulatory myelodysplasia patients was performed. Anatomic, radiographic, and functional parameters were evaluated to validate the respiratory-spinal structure relationship. Thirty-one patients diagnosed with nonambulatory myelomeningocele fulfilled the inclusion criteria. RESULTS: The imaging study confirmed the spinal deformity. Lung functions measured in this patient population describe reduced lung volumes by CT lung volume reconstruction, reduced vital capacity by spirometry, and reduced total lung capacity by the nitrogen washout method. Together, these findings suggest moderate restrictive respiratory disease. The blood count study did not show evidence of anemia or other blood disturbances. Echocardiogram analysis did not show pulmonary hypertension in any patient. CONCLUSION: The data validate the relationship between spinal structure and lung function. However, there is no simple structural feature that could help to diagnose thoracic insufficiency syndrome. Thus, the diagnosis continues to be based on a combination of clinical findings and radiological and respiratory function evaluations. LEVEL OF EVIDENCE: Level III.

Intra-atrial re-entrant tachycardia in congenital heart disease: types and relation of isthmus to atrial voltage.

Background: Intra-atrial re-entrant tachycardia (IART) is a frequent and severe complication in patients with congenital heart disease (CHD). Cavotricuspid isthmus (CTI)-related IART is the most frequent mechanism. However, due to fibrosis and surgical scars, non-CTI-related IART is also frequent. Objective: The main objective of this study was to describe the types of IART and circuit locations and to define a cut-off value for unhealthy tissue in the atria. Methods and results: This observational study included all consecutive patients with CHD who underwent a first ablation procedure for IART from January 2009 to December 2015 (94 patients, 39.4% female, age: 36.55 ± 14.9 years, 40.4% with highly complex cardiac disease). During the study, 114 IARTs were ablated (1.21 ± 0.41 IARTs per patient). Cavotricuspid isthmus-related IART was the only arrhythmia in 51% (n = 48) of patients, non-CTI-related IART was the only mechanism in 27.7% (n = 26), and 21.3% of patients (n = 20) presented both types of IART. In cases of non-CTI-related IART, the most frequent location of IART isthmus was the lateral or posterolateral wall of the venous atria, and a voltage cut-off value for unhealthy tissue in the atria of 0.5 mV identified 95.4% of IART isthmus locations. Conclusion: In our population with a high proportion of complex CHD, CTI-related IART was the most frequent mechanism, although non-CTI-related IART was present in 49% of patients (alone or with concomitant CTI-related IART). A cut-off voltage of 0.5 mV could identify 95.4% of the substrates in non-CTI-related IART.