Acute performance of stylet driven leads for left bundle branch area pacing: A comparison with lumenless leads

Background

Lumenless leads (LLLs) are widely used for left bundle branch area pacing (LBBAP). Recently, stylet-driven leads (SDLs) have also been used for LBBAP.

Objective

The purpose of this study was to evaluate the acute performance of SDLs during LBBAP in comparison with LLLs.

Methods

Consecutive patients undergoing LBBAP for bradycardia or cardiac resynchronization therapy indications at 2 high-volume, early conduction system pacing adopters, tertiary centers were included from January 2019 to July 2023. Patients received either SDLs or LLLs at the discretion of the implanting physician. Acute performance and follow-up data of both lead types were evaluated.

Results

A total of 925 LBBAP implants were included, 655 using LLLs and 270 using SDLs. Overall, LBBAP acute success was significantly higher with LLLs than SDLs (95.3% vs 85.1%, respectively; P <.001) even after the learning curve (97% vs 86%; P = .013). LLLs were implanted in more mid-basal septal positions in comparison with SDLs, which tended to be implanted in more inferior and mid-apical septal positions. Acute lead-related complications were higher with SDLs than LLLs (15.9% vs 6.1%, respectively; P <.001) with 15 cases of lead damage during implant (4.4% vs 0.5%; P <.001) but decreased with acquired experience and were comparable in the last 100 patients included in each group. Lead implant and fluoroscopy times were shorter for SDLs, with lead dislodgment occurring in 0.9% with LLLs and 1.5% with SDLs (P = .489).

Conclusion

Acute lead performance proved to be different between LLLs and SDLs. A specific learning curve should be considered for SDLs even for implanters with extensive previous experience with LLLs.

Tuberculosis of the clavicle presenting as an expansile lytic lesion: a case report

An unusual case of skeletal tuberculosis, presenting as an expansile osteolytic lesion in the lateral end of the clavicle is presented. Diagnostic confusion delayed appropriate medical therapy, leading to development of a discharging sinus with secondary infection, which further confused the picture. With re-emergence of tuberculosis as an important infection worldwide, and the ability of this disease to mimic many skeletal pathologies, this has to be included in the differential diagnosis, especially at unusual sites.

Tuberculosis of the sternoclavicular joints

From May 1991 to December 1997, we treated 9 patients with tubercular arthritis in 10 sternoclavicular joints. The patients presented with a painful swelling (7 joints), painless swelling (2 joints) and a painless (?) discharging sinus (1 joint) having a mean duration of symptoms of 13 (6-32) months. The diagnosis was made with fine-needle aspiration or open biopsy. In 1 patient debridement of the joint was combined with open biopsy. All patients were initially put on a 4-drug regimen of antitubercular therapy (ATT). 2 joints not responding to closed treatment were surgically debrided after 2-3 months of ATT. Total duration of ATT was 14-18 months. At final follow-up after average 4.5 (1.5-7.5) years, all lesions had healed. 3 patients had mild limitation of shoulder motion, with no pain, and 2 patients had a cosmetically ugly scar at the site of the sinus or biopsy.

Effects of elevated atmospheric CO(2) and temperature on leaf optical properties in Acer saccharum

Elevated partial pressures of atmospheric carbon dioxide, similar to numerous causes of plant stress, may alter leaf pigmentation and structure and thus would be expected to alter leaf optical properties. Hypotheses that elevated CO(2) pressure and air temperature would alter leaf optical properties were tested for sugar maple (Acer saccharum) in the middle of its fourth growing season under treatment. The saplings had been growing since 1994 in open-top chambers and partial shade at Oak Ridge, Tennessee under the following treatments: (1) ambient CO(2) pressure and air temperature (control); (2) CO(2) pressure approximately 30 Pa above ambient; (3) air temperatures 3 degrees C above ambient; and (4) elevated CO(2) and air temperature. Under elevated CO(2) or temperature, spectral reflectance, transmittance and absorptance in the visible spectrum (400-720 nm) tended to change in patterns that generally are associated with chlorosis, with maximum differences from the control near 700 nm. However, these changes were not significant at P=0.05. Although reflectance, transmittance and absorptance at 700 nm correlated strongly with leaf chlorophyll concentration, variability in chlorophyll concentration was greater within than among treatments. The lack of treatment effects on pigmentation explained the non-significant change in optical properties in the visible spectrum. Optical properties in the near-infrared (721-850 nm) were similarly unresponsive to treatment with the exception of an increased absorptance throughout the 739-850 nm range in leaves that developed under elevated air temperature alone. This response might have resulted from effects of air temperature on leaf internal structure.

Steffee variable screw placement system in the management of unstable thoracolumbar fractures: a Third World experience

Twenty consecutive patients with unstable thoracolumbar fractures were taken up for posterior spinal stabilization using the Steffee VSP system at the earliest opportunity. Patients were followed up from 20 to 38 months. 70% patients were operated within 3 weeks of sustaining injury (group 1) while injury-operation interval exceeded 3 weeks in 30% (group II). The average preoperative kyphotic angle was 19.35 degrees which improved to 8.70 degrees, the correction being much more in group I (17.60 degrees to 5.3 degrees) compared to group II (22.90 degrees to 14.40 degrees). The average preoperative vertebral body height was 57.75% which improved to 79.75%, the correction being much more in group I (61.20 to 88.40%) compared to group II (51.40 to 63.70%). No patients deteriorated neurologically while 7 out of 16 patients with neurological deficit showed improvement by one or more Frankel Grade (43.75%). It is concluded that reasonable correction of deformity, fair chance of neurological recovery and significant reduction of recumbency associated complications can be expected even when surgery is delayed.

Venous haemodynamics in both legs after total knee replacement

We studied the effect of total knee replacement on venous flow in 110 patients. Resting venous blood flow was measured using strain-gauge plethysmography before operation, after surgery and after discharge from hospital. There was a significant reduction in mean venous capacitance (p < 0.001) and mean venous outflow (p < 0.004) affecting only the operated leg. Both improved significantly after mobilisation in the early postoperative period, returning to preoperative levels by six days after surgery and before discharge from hospital. Our findings showed that venous stasis may contribute to deep-vein thrombosis only in the first few days after total knee replacement. This would be the most important period for the use of flow-enhancing prophylactic devices. Comparison with changes in blood flow after total hip replacement identified different patterns of altered haemodynamics suggesting that there are different mechanisms of venous stasis and thrombogenesis in hip and knee arthritis and during surgery for these conditions.