Effect of implantation site of the His bundle pacing leads on pacing parameters: a single-center experience.

BACKGROUND: HB pacing is a promising approach to achieve physiological pacing, but its efficacy and long-term effects require further validation. In current study, we deemed to investigate the effect of the His bundle pacing (HBP) lead location on pacing parameters. METHODS: 2D echocardiography imaging was performed after successful implantation, according to which the patients were divided into groups A (whose His lead tips were at the atrial side) and B (whose His lead tips were at the ventricular side). The capture thresholds, sensing values, and H-V intervals between the two groups were compared. RESULTS: Thirteen patients were in group A and 16 patients were in group B. The average capture thresholds during, 1 month, and 1 year after operation were 1.20 ± 0.34, 0.69 ± 0.29, and 0.92 ± 0.80 V/0.5 ms for group A and 1.14 ± 0.43, 0.81 ± 0.39, and 0.98 ± 0.59 V/0.5 ms for group B, respectively. The difference between the two groups was not significant. The threshold values in both groups decreased significantly in 1 month and slightly increased in 1 year. The sensing values of group A were 1.87 ± 0.82, 1.95 ± 0.76, and 1.88 ± 0.75 mV, while those of group B were 4.53 ± 1.37, 4.69 ± 1.38, and 4.59 ± 1.42 mV. The difference among the three time points was not significant. However, the sensing values in group A were consistently significantly lower than those in group B. The HV interval in group A was significantly longer than that in group B. CONCLUSIONS: The implantation site of HBP leads has a significant effect on sensing values for that His leads crossing the tricuspid annulus toward the ventricle are associated with higher sensing values, compared to a more proximal location. Meanwhile, lead location has no evident effect on capture thresholds that is improved significantly shortly after operation.

Inflammatory myofibroblastic tumor of the upper arm: A case report.

RATIONALE: Inflammatory myofibroblastic tumor (IMT) is an uncommon benign myofibroblastic tumor that usually occurs in the lung, mediastinum, abdomen and vulvovaginal region. IMT of the upper arm is exceedingly rare with unknown etiology. Pathology plays a major role in the diagnosis of IMT, and radiological characteristics of the condition are crucial for differential diagnosis. PATIENT CONCERNS: A 62-year-old woman was admitted to our hospital for a complaint of a mass in her left upper limb with progressive numbness in the extremity. Ultrasound examination of the brachial artery (BA) revealed a hypoechoic mass with well-defined borders and a substantial blood flow, and the mass was also shown to be greatly enhanced on computed tomography (CT) and magnetic resonance imaging (MRI). DIAGNOSIS: The subsequent histopathological and immunohistochemical studies led to the diagnosis of IMT. INTERVENTION: The patient was referred for surgery. The soft tissue tumor resection, left median nerve release operation, brachial artery vascular grafting, and arterial anastomosis were performed. OUTCOME: Favorable outcome was observed. The patient recovered well from the procedure and did not experience any further complications or tumor recurrence. LESSONS: In this report, we describe a case of IMT of the upper arm with BA involvement. The case expands the differential diagnosis of limb neoplasm and broadens the understanding of its ultrasonic and radiological imaging features. It also serves as a further example of an uncommon region distinct from conventional IMT. Further studies on the etiology and therapeutic strategies are needed.