How to Estimate QT Interval in Patients With Left or Right Bundle Branch Block: A Systematic Review.

PURPOSE/BACKGROUND: Prolonged QT interval related to psychopharmacological treatment is a risk factor for potentially life-threatening arrhythmias. Electrocardiographic measurements are recommended in patients with cardiovascular risk factors before initiating treatment with potentially QT-prolonging medications, such as certain antidepressants or antipsychotics. In patients with left bundle branch block (LBBB) or right bundle branch block (RBBB), conventional QT-estimation methods will lead to overestimation of the QT interval, as the conduction defect, reflected by the QRS duration, will increase the QT interval without representing longer repolarization as in drug-induced QT prolongation. METHODS/PROCEDURES: We conducted a systematic review of methods to estimate QT interval in the presence of LBBB or RBBB. We searched electronic databases Embase and Medline (last search, August 12, 2020). FINDINGS/RESULTS: We found 8 different methods, including linear correction formulae with and without correction for heart rate, or simpler formula correcting QRS duration with empirically derived modifiers. Only 3 of 8 methods were applicable in the presence of RBBB, whereas all 8 methods could be applied in the presence of LBBB. IMPLICATIONS/CONCLUSIONS: The QT interval is overestimated in patients with LBBB or RBBB, when using conventional measurements. Several alternative correction formulae exist, which can be applied using standard measurements from ordinary electrocardiographic readings. However, it is currently unknown whether or not the QT prolongation observed in the presence of bundle branch block significantly increases the risk of arrhythmias, as these formulae have not been tested against patient-specific clinical outcomes.

Cutdown Technique is Superior to Fascial Closure for Femoral Artery Access after Elective Endovascular Aortic Repair.

OBJECTIVES: Arterial access closure after endovascular aneurysm repair (EVAR) can be achieved using three different approaches: percutaneous closure devices, surgical exposure and direct suture ("cutdown"), and the less invasive fascial closure technique. The aim of this study was to report on the intra-operative, in hospital, and three month outcome of fascial closure and cutdown, and to determine risk factors for failure. METHODS: The primary outcome was assessed in 439 groins in 225 elective EVAR patients recruited consecutively and prospectively from February 1, 2011 to August 31, 2014. During the study period, fascial closure and cutdown were first and second line closing techniques. Compared with fascial closure, procedures completed with cutdown had lower BMI, thinner subcutaneous tissue of the groin and more complex femoral anatomy. Computed tomographic angiography (CTA) and duplex ultrasound (DUS) of the groin were performed pre-operatively and three months after EVAR. Retrospective review of medical records and CTA were used to determine intra-operative and in hospital outcome, and risk factors for failure. RESULTS: In total, 64%, 33%, and 3% were completed with fascial closure, cutdown, and closure device, respectively. Intra-operative, in hospital, and three month technical success rates of fascial closure vs. cutdown were 91% (283/310 groins) vs. 99% (114/115 groins), 89% (277/310 groins) vs. 99% (114/115 groins), and 89% (275/310 groins) vs. 99% (114/115 groins) (p < .001). Wound complications within three months were infrequent for both methods. No risk factor was significantly associated with failure after fascial closure. CONCLUSION: This study shows that cutdown is superior to fascial closure for femoral artery access after elective EVAR. In acute EVAR, however, fascial closure is still considered to be a good and fast method, and it has been kept in the present authors' armamentarium for this indication.