Investigating factors that influence change from a traditional to asocio-constructive teaching paradigm: Teachers’ beliefs, alternate conceptions and external factors

This study sought to better understand teachers’ implementation of reform initiatives. Multiple research methods, including surveys (N=198 teachers), interviews and observations (N=15 case study teachers) highlighted an incongruence between teachers’ perceived and observed practice. Important factors that influenced implementation were identified, including: lack of knowledge of constructivist practice; misinterpretation of terminology; time constraints; and lack of support from the school administration. The findings could assist in better understanding change in teachers’ practice during education reform

Surgical cure of the Wolff-Parkinson-White syndrome a comparison of two techniques

Curative arrhythmia surgery for patients with symptomatic Wolff-Parkinson-White syndrome (WPW) was first performed in South Africa in November 1987. Pre-operatively all patients were symptomatic despite medical therapy, and 32% were assessed as being at risk for sudden death. The first 9 patients (November 1987 to December 1989) underwent either epicardial or localised endocardial surgical dissections, and a cure was obtained in 66%. Aberrant atrioventricular conduction recurred in 2 patients, 30 atrioventricular heart block occurred in 2 patients, and there was 1 postoperative death in a patient who had undergone simultaneous coronary artery bypass grafting. In contrast, a standardised endocardial technique was used in the subsequent 10 patients. Surgical cure was obtained in all 10 patients (P < 0,01). However, 1 patient required reoperation 24 hours after the first procedure because of early postoperative recurrence due to initial incorrect pathway localisation. This was successful. There were no deaths, and no patient developed atrioventricular heart block. In view of the excellent surgical results, arrhythmia surgery should be considered in select WPW patients who either have refractory symptoms or are at risk for sudden death. Furthermore, this reliable surgical technique provides an essential back-up should alternative interventionalprocedures such as percutaneous radiofrequency ablation fail

Surgery for the Wolff-Parkinson-White syndrome - the Groote Schuur Hospital experience

Surgical division of accessory atrioventricular (AV) connections has been performetl on 9 patients with the WolffParkinson- White (WPW) syndrome at Groote Schuur Hospital. All patients had symptomatic paroxysmal tachycardia. The indication for surgery in 5 patients was poor control on antiarrhythmic drugs. Surgery was performed on a 15-year-old boy to prevent lifelong dependence on drugs, although his atrial fibrillation (ventricular rate> 300/min) was controllable with sotalol 1 280 mg daily. The remaining 3 patients required cilrdiac surgery for other indications and therefore their accessory pathways (APs) were divided concurrently. The AP was localised by pre-operative endocardial mapping and intra-operative epicardial mapping. There were 4 posteroseptal, 3 left free-wall and 2 right free-wall pathways. An endocardial approach was used to divide the pathways. All 5 free-wall APs were successfully divided without complications or recurrence. However, 1 patient with paroxysmal atrial fibrillation and severe unstable angina·due to coronary artery disease died unexpectedly 10 days after 4-vessel coronary bypass grafting and division of a posteroseptal AP. Postoperative complications occurred in a further 2 patients with posteroseptal APs. One patient developed complete heart block and is now asymptomatic with a DDD pacemaker, while the other had recurrence of retrograde bypass conduction postoperatively, but is now successfully controlled on sotalol. Therefore 7 of the 8 survivors are free of recurrence of tachycardia on no anti-arrhythmic drugs after a mean follow-up of 14,3 months. New insights into the surgical technique, particularly for division of posteroseptal pathways, can be expected to improve the outlook

Traumatic rupture of the descending thoracic aorta

The management of acute traumatic rupture of the descending thoracic aorta at Groote Schuur Hospital between January 1984 and December 1989 is reviewed. Aortic rupture was diagnosed angiographically in 18 of 150 patients (12%), who underwent aortography because this injury was suspected. However. 3 of these patients had false-positive angiograms. The diagnosis was initially missed in 31% of patients, and this contributed to morbidity and mortality. Simple aortic crossclamping (N = 8) was used before September 1988 and 3 patients died - 1 intra-operatively from cardiac arrhythmia and 2 postoperatively, where major peri-operative haemorrhage had occurred. In contrast, partial heparin-less bypass (N = 5) using a centrifugal vortex pump was used after September 1988, and there were no haemorrhagic or paraplegic complications or mortality in this group. This technique is safe and appears to be superior to simple aortic crossclamping in managing this condition

X marks the spot: catheter aspiration using the Inari FlowTriever device to debulk defibrillator lead vegetations prior to transvenous lead extraction—a case report

Background: When cardiac implantable electronic device infection occurs, standard therapy is usually total system extraction. Transvenous lead extraction is preferable to open heart surgical extraction, unless contraindicated because of the presence of very large vegetations on the intravenous leads according to the European Society of Cardiology guidelines. Extraction of transvenous leads with vegetations risks distal embolism resulting in obstruction and/or infection in the pulmonary arteries. Catheter aspiration of vegetations or thrombi has been performed prior to transvenous lead extraction using a partial veno-venous extracorporeal bypass circuit. We report the use of a single-access aspiration system using the Inari FlowTriever 24 French system to debulk a defibrillator lead before percutaneous extraction. Case summary: A 79-year-old male presented with fever 18 years after his first implantable cardioverter defibrillator implant and 9 years after his most recent pulse generator change. Two large vegetations were identified on his transvenous defibrillator lead on the atrial aspect, near the tricuspid annulus, which were aspirated using the Inari Medical 24Fr FlowTriever aspiration catheter. We describe anatomical considerations during the approach and a technique to localize the vegetations based on a combination of fluoroscopy and transoesophageal echocardiogram guidance. Discussion: This case demonstrates the safe and effective use of the Inari Medical 24Fr FlowTriever aspiration catheter in debulking a defibrillator lead before transvenous lead extraction. This method uses a single venous puncture and is not dependent on extracorporeal bypass. Apart from reducing complexity, this technique may be advantageous in patients where anticoagulation needs to be minimised

Hybrid Procedure for a Traumatic Aortic Rupture Consisting of Endovascular Repair and Minimally Invasive Arch Vessel Transposition without Sternotomy

Emergency surgical repair for acute traumatic aortic ruptures has been associated with a high peri-procedural mortality rate. Endovascular stent-grafting, as a less invasive procedure, has shown encouraging results. This report describes a patient with a short landing zone, who was treated by transposing the supra-aortic branch without sternotomy, followed by covered stent-grafting with an extended proximal bare portion to enhance fixation

Outcome of major cardiac injuries at a Canadian trauma center

BACKGROUND: Canadian trauma units have relatively little experience with major cardiac trauma (disruption of a cardiac chamber) so injury outcome may not be comparable to that reported from other countries. We compared our outcomes to those of other centers. METHODS: Records of patients suffering major cardiac trauma over a nine-year period were reviewed. Factors predictive of outcome were analyzed. RESULTS: Twenty-seven patients (11 blunt and 16 penetrating) with major cardiac trauma were evaluated. Injury severity scores (ISS) were similar for blunt (49.6 ± 16.6) and penetrating (39.5 ± 21.6, p = 0.20) injuries. Five of 11 blunt trauma patients, and 9 of 16 penetrating trauma patients, had detectable vital signs on hospital arrival (p = 0.43). Ten patients underwent emergency department thoracotomy and 11 patients had cardiac repair in the operating theatre. Eleven patients survived and 16 died. Survivors had a lower ISS (33.7 ± 15.4) than non-survivors (50.4 ± 20.4; p = 0.03). Two of 11 blunt trauma patients and 9 of 16 penetrating trauma patients survived (p = 0.06). Eleven of 14 patients with detectable vital signs survived; all 13 without detectable vital signs died (p = 0.00003). Ten of eleven patients treated in the operating theatre survived, while only one of the other 16 patients survived (p = 0.00002). CONCLUSIONS: Patients with major cardiac injuries and detectable vital signs on hospital arrival can be salvaged by prompt surgical intervention in the operating theatre. Major cardiac injuries are infrequently encountered at our center but patient survival is comparable to that reported from trauma units in other countries