Long-term prognostic value of vasodilator stress cardiac magnetic resonance in patients with atrial fibrillation.

AIMS: Although the prevalence of coronary artery disease (CAD) is high among patients with atrial fibrillation (AF), studies on stress perfusion cardiac magnetic resonance (CMR) imaging frequently exclude patients with AF, and its prognostic and diagnostic value in high-risk patients with suspected or known CAD remains unclear. METHODS AND RESULTS: In this longitudinal cohort study, we included 164 consecutive patients with AF during vasodilator perfusion CMR. Diagnostic value was evaluated regarding invasive coronary angiography in a subset of patients. We targeted a follow-up of >5 years and used CMR results as stratification, and the primary outcome was major adverse cardiac events [MACE, cardiovascular (CV) death and myocardial infarction (MI)]. Secondary outcomes included late coronary revascularization or stroke and the components of the primary outcome. Of the whole cohort (73.8% male, mean age 72.2 years ± 7.8 SD), 99.4% were successfully scanned (163/164 patients). Median CHA2DS2-VASc score was 4 [interquartile range (IQR) 3-5], and median 10-year risk for CV events based on SMART risk score was high (24%, IQR 16-32%). Thirty-two patients (19.6%) presented with ischaemia and 52 patients (31.9%) with late gadolinium enhancement (LGE). A combination of LGE and inducible ischaemia was present in 20 patients (12.3%). Diagnostic accuracy was 86.2% [confidence interval (CI) 68.3-96.1%]. The median follow-up was 6.6 years (IQR 3.6-7.8). Ischaemia in vasodilator perfusion CMR was significantly associated with the occurrence of MACE [P < 0.01; hazard ratio (HR) 2.65, CI 1.39-5.08], as well as LGE (P = 0.03; 1.74, CI 1.07-3.64) and the combination of both (P < 0.01; HR 2.67, CI 1.59-5.62). After adjustment by age, left ventricular ejection fraction, and the presence of diabetes, ischaemia in vasodilator perfusion CMR remained significantly associated with the occurrence of MACE (2.10, CI 1.08-4.10; P = 0.03). In secondary endpoint analysis, there was a significant association of ischaemia in CMR with CV death (P < 0.05; HR 1.93, CI 0.95-3.9) and MI (P < 0.01; HR 13, CI 1.35-125.4), while no significant association was found regarding the occurrence of revascularization (P = 0.45; HR 1.43, CI 0.57-3.58) or stroke (P = 0.99; HR 0.99, CI 0.21-2.59). CONCLUSIONS: Vasodilator stress perfusion CMR demonstrated an excellent diagnostic and significant prognostic value at long-term follow-up in high-risk patients with persistent AF and suspected or known CAD.

Anatomy of strike-slip fault tsunami genesis.

Tsunami generation from earthquake-induced seafloor deformations has long been recognized as a major hazard to coastal areas. Strike-slip faulting has generally been considered insufficient for triggering large tsunamis, except through the generation of submarine landslides. Herein, we demonstrate that ground motions due to strike-slip earthquakes can contribute to the generation of large tsunamis (>1 m), under rather generic conditions. To this end, we developed a computational framework that integrates models for earthquake rupture dynamics with models of tsunami generation and propagation. The three-dimensional time-dependent vertical and horizontal ground motions from spontaneous dynamic rupture models are used to drive boundary motions in the tsunami model. Our results suggest that supershear ruptures propagating along strike-slip faults, traversing narrow and shallow bays, are prime candidates for tsunami generation. We show that dynamic focusing and the large horizontal displacements, characteristic of strike-slip earthquakes on long faults, are critical drivers for the tsunami hazard. These findings point to intrinsic mechanisms for sizable tsunami generation by strike-slip faulting, which do not require complex seismic sources, landslides, or complicated bathymetry. Furthermore, our model identifies three distinct phases in the tsunamic motion, an instantaneous dynamic phase, a lagging coseismic phase, and a postseismic phase, each of which may affect coastal areas differently. We conclude that near-source tsunami hazards and risk from strike-slip faulting need to be re-evaluated.

Total knee replacement with tibial tubercle osteotomy in rheumatoid patients with stiff knee.

PURPOSE: Total knee arthroplasty (TKA) is a well-proven modality that can provide pain relief and restore mobility for rheumatoid arthritis (RA) patients with advanced joint destruction. Patellar ligament avulsion, especially in presence of poor bone quality and knee stiffness, is one of the special considerations that must be addressed in this unique population of patients. This study aimed to determine the functional results in a series of rheumatoid patients with stiff knee and end-stage joint destruction who underwent tibial tubercle osteotomy during TKA. METHODS: Twenty-three knees in 20 patients (16 women; four men) at a mean age of 54 years with end-stage arthritis and knee stiffness due to RA were operated upon for TKA using tibial tubercle osteotomy as a step during the operation. Patients were reviewed clinically and radiographically with a minimum follow-up of two years. Complications were noted. Hospital for Special Surgery (HSS) score was recorded pre-operatively and at six and 12 months postoperatively. RESULTS: Union occurred at the osteotomy site in 21 of 23 cases. One case had deep venous thrombosis (DVT). There was no infection or periprosthetic fracture, and at last follow-up, no patient required revision. HSS score improved from 46 (15-60) pre-operatively to 85 (71-96) post-operatively. CONCLUSION: Tibial tubercle osteotomy during TKA in patients with RA and stiff knee is technically demanding yet proved to be effective in improving post-operative range of movement and minimising the complication of patellar ligament avulsion.

Laryngeal mask airway vs. uncuffed endotracheal tube for nasal and paranasal sinus surgery: paediatric airway protection.

BACKGROUND AND OBJECTIVE: Risks are anticipated for laryngeal mask airway (LMA) anaesthesia during nasal and sinus surgeries because blood can trickle posteriorly into the hypopharynx and contaminate the airway. This study was conducted to determine whether a LMA could provide adequate airway protection from the expected intraoperative bleeding. METHODS: After obtaining ethics committee approval, 60 children ASA status I or II, 1-12 years of age, and scheduled for nasal and sinus surgery were randomized to one of two groups, endotracheal tube (ETT) or LMA, with 30 patients in each. Topical lidocaine with adrenaline was used in all patients, and throat packs were used for the ETT group. The airway was examined using a fibreoptic endoscope in order to determine whether blood or tissue debris soiled the supraglottic airway or trachea. After extubation, LMAs and ETTs were examined for soiling by blood and graded on a scale of 0-3. For ETT, the grades were 0, none; 1, contamination above the mark for vocal cord depth; 2, contamination below the mark for vocal cord depth; and 3, contamination interiorly. For LMA, they were 0, no staining; 1, staining on the anterior aspect of the cuff of the LMA; 2, staining inside the cup of the LMA; and 3, staining found in the tube. RESULTS: Blood stains were found in the larynx of one child in the LMA group. In the ETT group, there were three cases of staining (two supraglottic and one in the trachea, P = 0.161). With the LMA, 12 (40%) and 18 (60%) patients had visual contamination scores of 0 and 1, respectively. With the ETT, 14 (46.7%), 10 (33.3%), and six (20%) patients had visual contamination scores of 0, 1, and 2, respectively (P = 0.0123). CONCLUSION: LMA is a suitable method for paediatric patients undergoing sinonasal surgery because it offers airway protection from blood contamination comparable to that of a standard uncuffed ETT with throat pack.

Comparison of the outer diameter of the 'best-fit' endotracheal tube with MRI-measured airway diameter at the cricoid level.

BACKGROUND AND OBJECTIVE: In this study, we evaluated the ratio of the outer diameter of an uncuffed Mallinckrodt endotracheal tube (ETT, Mallinckrodt Tyco Healthcare UK Ltd) to the MRI-measured internal transverse airway diameter (ITD) at the cricoid level in children. METHODS: With institutional ethics committee approval and parental consent, we measured the ITD at the cricoid level from MRI images of children undergoing MRI diagnostic procedures requiring general anaesthesia with orotracheal intubation. The ITD at the cricoid level was compared with the outer diameter of the utilized ETT. Linear regression analysis was employed to assess the correlation of tracheal diameter with age, height and weight. For all tests, a P value of less than 0.05 was considered to be statistically significant. RESULTS: Fifty patients were studied (21 girls and 29 boys). The difference between the ITD at the cricoid level and the outer tracheal tube diameter ranged from 0.1 to 1.7 mm (median 0.7 mm). The internal transverse tracheal diameters had a strong association with age (r=0.7077, P<0.001), a moderate association with height (r=0.5928, P<0.001), and a mild association with weight (r=0.2437, P<0.001). CONCLUSION: The outer diameter of the 'best-fit' ETT was less than the ITD at the cricoid level by 0.1-1.7 mm. The correlation of the outer diameter of the 'best-fit' ETT with age was stronger than with height or weight.