Directed Reading: Designing a Professional Development Program for Medical Radiation Technologists.

By participating in some form of professional development, medical radiation technologists can increase their skill, knowledge, and competence, leading to improved quality, safety, and standards of practice. Participation will also demonstrate acceptance of the responsibility for medical radiation technologists' own professional development. Over the past 10 years, the profession of medical radiation technology has progressed dramatically, with many changes in technology. The need for medical radiation technologists to keep up-to-date on these advancements is evident. Many medical radiation technologists participate in some form of professional development, and the decision to do so is either mandated at the provincial level or it remains a personal one. Because education is a provincial matter, the continuity of professional development or continuing education for medical radiation technologists across the country does not exist. The purpose of this directed reading is to review the options available to medical radiation technologists for professional development, to provide an overview of professional development programs from various health care professional groups, to outline how to effectively introduce a professional development program to medical radiation technologists, and to recommend the most appropriate program to implement for medical radiation technologists.

Locations of ectopic beats coincide with spatial gradients of NADH in a regional model of low-flow reperfusion.

We studied the origins of ectopic beats during low-flow reperfusion after acute regional ischemia in excised rat hearts. The left anterior descending coronary artery was cannulated. Perfusate was delivered to the cannula using an high-performance liquid chromatography pump. This provided not only precise control of flow rate but also avoided mechanical artifacts associated with vessel occlusion and deocclusion. Optical mapping of epicardial transmembrane potential served to identify activation wavefronts. Imaging of NADH fluorescence was used to quantify local ischemia. Our experiments suggest that low-flow reperfusion of ischemic myocardium leads to a highly heterogeneous ischemic substrate and that the degree of ischemia between adjacent patches of tissue changes in time. In contrast to transient ectopic activity observed during full-flow reperfusion, persistent ectopic arrhythmias were observed during low-flow reperfusion. The origins of ectopic beats were traceable to areas of high spatial gradients of changes in NADH fluorescence caused by low-flow reperfusion.

Controlled regional hypoperfusion in Langendorff heart preparations.

We describe a new approach that combines several techniques to allow abnormal electrical and calcium activity to be visualized within hypoperfused myocardial tissue. A flexible microcannula was inserted into the left anterior descending artery of Langendorff perfused rat hearts, an air-tight seal between the coronary artery and the cannula was created, and an HPLC pump was used to deliver a specified flowrate through the microcannula. High resolution optical mapping of NADH/calcium, NADH/voltage or calcium/voltage was then conducted using a dual camera system. The ECG was acquired using surface electrodes. This perfusion technique is superior to occluding a vessel by either a tie or a clamp because it allows precise control of the composition and amount of flow to a defined ischemic bed. Another advantage is that flow can be stopped and resumed remotely, without touching the heart. This allows ectopic beats, or other arrhythmogenic activity, such as alternans, to be recorded immediately after changes in flow are imposed. Altogether, the described method provides a powerful new tool to assess how coronary flow rate affects the degree of local ischemia by the ability to record abnormal patterns of electrical activity and associated intracellular calcium transients with high spatiotemporal resolution from epicardial areas as small as 100 x 100 microm.