Phrenic nerve stimulation is a rare but recognized complication of pacemaker implantation. The unique presentation of singultus in the presence of a pacemaker does not warrant initial concerns for pacemaker dislodgement, however in conjunction with muscle twitching and recent insertion of said pacemaker, lead dislodgement becomes more likely. We describe a 62-year-old male with history of right nephrectomy and recent placement of dual-chamber pacemaker for complete heart block presented seven days post procedure with right pectoralis muscle twitching and persistent singultus. Electrocardiogram showed an atrial-ventricular paced rhythm. Chest radiography revealed interval retraction of the right atrial lead with ventricular lead remaining in place. Device interrogation confirmed atrial lead dislodgement with subsequent phrenic nerve stimulation. The device was reprogrammed to ventricular-only pacing mode (VVIR), resulting in resolution of symptoms, however it was not a permanent solution. The patient was discharged with plans for outpatient lead revision. Atrial lead dislodgement can result in phrenic nerve stimulation and uncommon symptoms such as singultus and twitching of chest muscles. Prompt recognition of the underlying etiology and reprogramming of the pacemaker can alleviate symptoms and guide further management.
Importance:Babesiosis is a worldwide emerging tick-borne disease with an expanding geographic range in the US, Europe, and Asia. Red blood cell exchange transfusion (ET) is often used as an adjunctive treatment for severe illness from babesiosis, particularly in patients with high parasitemia, acute organ injury, or severe hemolytic anemia. Data supporting its clinical effectiveness, however, are lacking. Objective:To test whether ET improves clinical outcomes among hospitalized adult patients with severe babesiosis. Design, Settings, and Participants:This target trial emulation used data from a multicenter cohort study of 3233 consecutive adults hospitalized with babesiosis from 2010 to 2024 at 82 sites across the northeastern US. Patients were eligible if they had parasitemia greater than 10%, or 5% to 10% with either acute organ injury or severe hemolytic anemia. Data were analyzed from April to August 2025. Exposure:Treatment with ET in the first 7 days of hospitalization. Main Outcomes and Measures:A composite of in-hospital death or 30-day readmission. Outcomes were compared between patients who received ET within the first 7 days of admission and those who did not. The analysis used logistic regression, with inverse probability of treatment weighting (IPTW) to adjust for potential confounders. Results:The analysis included 629 patients (median [IQR] age, 71 [63-79] years; 446 male [70.9%]), among whom 209 (33.2%) received ET in the first 7 days of hospitalization. Patients treated with ET were more severely ill at baseline than those not treated with ET (median parasitemia, 14.0% vs 7.2%); however, severity of illness characteristics were well balanced after applying IPTW. In the main analysis, the primary end point occurred in 3.6% of patients who received ET and in 9.8% who did not (adjusted odds ratio, 0.22; 95% CI, 0.09-0.51). The benefit of ET was confirmed in multiple sensitivity analyses. Conclusions and Relevance:This multicenter cohort study found that among severely ill adults hospitalized with babesiosis, the adjusted risk of in-hospital death or 30-day readmission was nearly 5-fold lower in those treated with ET vs those not treated with ET. These data support ET for severely ill patients with babesiosis, although the findings may be susceptible to unmeasured confounding. Further research is needed to identify which patients are most likely to benefit.
Abstract Introduction Durvalumab, a PD-L1 inhibitor used as consolidation therapy for stage III non-small cell lung cancer (NSCLC), has been associated with severe immune-related pneumonitis as a treatment-related side effect. While Checkpoint inhibitor pneumonitis (CIP) is primarily considered an autoimmune-mediated toxicity, infectious factors may amplify pulmonary inflammation and alter disease severity. We report a case of grade 4 durvalumab induced pneumonitis associated with concurrent Pneumocystis jirovecii infection (PJP). Case Report A 69-year-old female with a past medical history of stage IIIB NSCLC (Status post chemoradiation followed by durvalumab therapy 3 months prior to admission), psoriatic arthritis (Discontinued infliximab 8 months ago and methotrexate 2 months prior to admission) and remote smoker but no underlying lung disease, presented to the emergency department with progressive dyspnea. She was initially hemodynamically stable but developed worsening hypoxemia, eventually requiring high-flow nasal cannula. Laboratory workup was significant for positive beta-d-glucan, but otherwise was unremarkable. Autoimmune testing revealed a positive P-ANCA but negative MPO and PR3 antibodies. Chest CT demonstrated diffuse bilateral perihilar ground-glass opacities notably in left upper lobe and known cavitation of left lower lobe mass, with imaging consistent with CIP. Bronchoscopy with bronchoalveolar lavage was notably positive for Pneumocystis jirovecii PCR, but negative for Direct Fluorescent Antibody (DFA), for which she was started on trimethoprim-sulfamethoxazole. Durvalumab was discontinued, and the patient required high-dose intravenous corticosteroids and three days of IVIG for her severe pneumonitis. Her oxygenation and symptoms slowly improved. She was discharged on a prolonged three-month prednisone taper and placed on trimethoprim-sulfamethoxazole prophylaxis during steroid therapy. Discussion This case highlights that P. jirovecii infection, whether active or colonizing, may serve as an immune trigger, amplifying pulmonary inflammation and precipitating or worsening durvalumab-associated pneumonitis. Linkage between P. jirovecii colonization and CIP development has not previously been explored. Our case suggests that PJP colonization or active infection may worsen the clinical course and outcomes of pneumonitis primarily driven by durvalumab and proposes that concomitant PJP infection be considered a novel risk factor for the severity of durvalumab-induced pneumonitis. This abstract is funded by: None
Objective To examine bidirectional longitudinal associations between MRI-detected structural changes and pain between knees (within a person) with or at risk for osteoarthritis (OA). Design Using data from the Osteoarthritis Initiative (OAI) with a bidirectional knee-based design, each participant contributed two observations by alternating one knee as the exposure knee and the other as the contralateral (outcome) knee. MRI-based composite metrics of disease activity and cumulative damage were assessed over two years. Knee pain was measured using The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Multinomial logistic regression estimated associations between baseline or changes in MRI from one knee and changes in the contralateral knee pain. Linear regression assessed associations between baseline or changes in structural metrics of one knee and changes in the contralateral knee. Results The sample included 625 knee pairs (1,250 knees) from 303 participants, with some contributing data from multiple intervals. Baseline measures or longitudinal changes in disease activity or cumulative damage in the one knee were not associated with two-year changes in pain in the contralateral knee. Two-year changes in disease activity (adjusted β=0.16, 95% CI: 0.05 to 0.27) and cumulative damage (adjusted β=0.16, 95% CI: 0.03 to 0.30) were associated with contralateral knee disease activity and cumulative damage changes, respectively. Conclusions Structural worsening in one knee was not associated with contralateral pain but correlated with concurrent structural worsening in the other knee, suggesting parallel bilateral progression and the need to consider both knees in OA studies and therapeutic trials.
