Background: Bortezomib is a novel, first-in-class peptide which reversibly inhibits the proteasome and is Food and Drug Administration approved for the treatment of multiple myeloma, non-Hodgkin lymphoma, Waldenström’s macroglobulinemia, and systemic light chain amyloidosis, among others. Case Report: Very few cases of bortezomib-induced cardiotoxicity have been reported in the literature, and most of them have been confounded by the previous use of anthracyclins. We reviewed the case of a 56-year-old woman with a medical history of well-controlled hypertension who was newly diagnosed with International Staging System stage I multiple myeloma. She presented with new symptoms of exertional dyspnea, paroxysmal nocturnal dyspnea, and orthopnea after a 4th cycle of a bortezomib/dexamethasone-based chemotherapy. Clinical examination was consistent with heart failure. 2-D echocardiogram showed an left ventricular ejection fraction of 25%, abnormal wall motion, severe eccentric mitral regurgitation, and moderate pericardial effusion. Coronary angiogram showed normal coronaries, and cardiac magnetic resonance did not show delayed gadolinium enhancement. Conclusion: We reviewed the possible mechanisms involved in cardiotoxicity caused by bortezomib, and the diagnostic methods and importance of early identification of this adverse event. Differential diagnoses such as cardiac amyloidosis and viral myocarditis are also discussed. To our knowledge, this is the first case where pericardial effusion and mitral regurgitation were described after bortezomib treatment.

Subclavian artery stenosis has long been treated with great success with bypass surgery. Percutaneous intervention, often used in combination with stent placement, has come into vogue for the past few years as a safe and effective therapeutic modality. This study aimed to compare angioplasty alone with angioplasty followed by stent placement by combining available data. The objective of this study was to perform a review of the available literature to compare the efficacy of percutaneous transluminal angioplasty (PTA) alone with PTA followed by stent placement for proximal subclavian artery stenosis. Successful recanalization was defined as patency at the end of 1 year, and reocclusions and restenoses were noted as events for the purpose of pooling the data. The authors searched the Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, PubMed, EMBASE, and CINAHL databases for relevant trials/studies comparing PTA and PTA with stenting. Review authors independently assessed the methodological quality of studies (focusing on the adequacy of the randomization process, allocation concealment, blinding, completeness of follow-up, and intention-to-treat analysis) and selected studies for inclusion. All retrospective observational studies were also included in the analysis in the absence of double-blinded randomized trials for increasing sample size. All analyses were done using RevMan 5.0. Odds ratio was calculated using Mantel-Haenszel test with a fixed effect model. All included studies were assessed by all authors for potential sources of bias. Eight studies were included in the analysis having 544 participants. Stenting after PTA was significantly superior to angioplasty alone for treatment of subclavian artery stenosis and maintenance of patency at 1 year, as indicated by absence of events (P = 0.004; 95% confidence interval, odds ratio 2.37 [1.32-4.26]) without significant complication rates for either procedure. There is evidence in favor of stent placement after angioplasty for successful recanalization of stenosed subclavian arteries and long-term maintenance of patency without significant increase in risk for major complications in subjects.

Introduction: Ventricular pacing (VP) may impact the accuracy of QT interval measurement, as it increases the QT by increasing the QRS duration amongst other mechanisms. We aimed to investigate the accuracy of the commonly used clinical practice of subtracting 50 ms from the corrected QT (QTc) in ventricular paced rhythms. Methods: We conducted a prospective observational study on 23 consecutive pacemaker patients. Four ECGs were recorded for each subject, 2 in their native rate and 2 following an atrial paced, atrial sensed and inhibited response to sensing and then a dual pacing, dual sensing and dual response pacing of 100 bpm to allow for an intrinsic and a ventricular paced QRS, respectively. The averaged QTc in the ventricular paced rhythm was then compared with the non-ventricular-paced QTc for individual subjects. Results: At a mean spontaneous heart rate of 66 bpm (SD ±8), the mean difference in QTc between the ventricular paced and nonpaced QRS was 48.27 ms (95% CI = 32-64.6 ms, p < 0.001). At faster paced rates, the mean QTc difference was 81.3 ms (95% CI = 35.8-126.8 ms, p = 0.002). Conclusions: The QTc measurement during VP confirms the current 50-ms subtraction assumption rule within a range of ±16 ms at an average heart rate of 66 bpm. However, at faster heart rates, the 50-ms adjustment may underestimate the QTc discrepancy between a wide and normal QRS.