Optimizing physicians' instruction of PACS through e-learning: cognitive load theory applied.

This article outlines the strategy used by our hospital to maximize the knowledge transfer to referring physicians on using a picture archiving and communication system (PACS). We developed an e-learning platform underpinned by the cognitive load theory (CLT) so that in depth knowledge of PACS' abilities becomes attainable regardless of the user's prior experience with computers. The application of the techniques proposed by CLT optimizes the learning of the new actions necessary to obtain and manipulate radiological images. The application of cognitive load reducing techniques is explained with several examples. We discuss the need to safeguard the physicians' main mental processes to keep the patient's interests in focus. A holistic adoption of CLT techniques both in teaching and in configuration of information systems could be adopted to attain this goal. An overview of the advantages of this instruction method is given both on the individual and organizational level.

[Do hospital physicians really want to go digital? --Acceptance of a picture archiving and communication system in a university hospital]. / Möchten Krankenhausärzte wirklich auf digitale Systeme umsteigen?--Die Akzeptanz gegenüber einem Bildarchivierungs- und Ubermittlungssystem in einer Universitätsklinik.

PURPOSE: Radiology departments are making the transition from analog film to digital images by means of PACS (Picture Archiving and Communication System). It is critical for the hospital that its physicians adopt and accept the new digital work method regarding radiological information. The aim of this study is to investigate hospital physicians' acceptance of PACS using questionnaires pre- and post-implementation and to identify main influencing factors. MATERIALS AND METHODS: The study was conducted in an 1169 bed university hospital. The UTAUT (Unified Theory of Acceptance and Use of Technology) questionnaire was administered at two times: one month pre-implementation (T1) and 1.5 years post-implementation (T2) of PACS, targeting all hospital physicians with the exemption of radiologists. The UTAUT scales (Behavioral Intention BI; Facilitating Conditions FC; Effort Expectancy EE; Performance Expectancy PE; Anxiety ANX; Social Influence SI; System Use USE; Attitude toward technology ATT; Self-Efficacy SE) were used to assess questions regarding: a) PACS' usefulness, b) PACS' ease of learning/using, c) PACS support availability, d) the perceived pressure to use PACS, e) physicians' attitude towards PACS and f) physicians' intention to use and actual use of PACS. RESULTS: At T 1 scale ratings were positive toward the PACS implementation. The ratings on all scales with the exception of self-efficacy improved at T 2. Regression analysis revealed that the key factor for intention to use PACS at T 1 was the usefulness of PACS, while the availability and awareness of support was its most important predictor at T 2. Overall, PE was the best predictor of BI, but all four UTAUT-determinants (PE, FC, EE and SI) were salient for its prediction. Variance explained in BI ranged from 31 to 37 % while variance explained in USE was very low (3 %). CONCLUSION: The implementation of PACS has succeeded. At T 1 the physicians were welcoming PACS and this was confirmed at T 2. Experience with PACS led to an overall improved attitude toward PACS. The key factors for physicians' intentions to use PACS were the usefulness of PACS (at T 1 and overall) and the availability of support (at T 2).

User acceptance of a picture archiving and communication system. Applying the unified theory of acceptance and use of technology in a radiological setting.

OBJECTIVE: The aim of this study is to gain insight into the individual user acceptance of PACS by the radiology department staff of the Ghent University Hospital. Hereto a basic--direct effects only--form of UTAUT was assessed. METHODS: Ninety-four questionnaires were distributed and 56 usable questionnaires were returned (19 radiologists - 37 technologists). The questionnaire consisted of scales of Venkatesh et al. [13] for performance expectancy (PE), effort expectancy (EE), facilitating conditions (FC), social influence (SI), self-efficacy (SE), attitude (ATT), anxiety (ANX) and behavioral intention (BI), and a scale of Moore et al. [22] to assess the perceived voluntariness of PACS-use. RESULTS: The reliability of all scales, except FC and voluntariness, was acceptable to good. The voluntariness scale was divided into a mandatoriness (MAN) and a voluntariness (VOL) measure. Both radiologists and technologists seem to welcome PACS, with radiologists having higher ratings on PE, EE, ATT, VOL and BI. Only PE and FC were salient for predicting BI, while EE and SI were not salient. Variance explained in behavioral intention to use PACS was 48%. CONCLUSION: Both radiologists and technologists were positive towards PACS and had strong intentions to use PACS. As other healthcare professionals, they appear to make their technology acceptance decision independent from their superiors, hereby focusing on usefulness rather than on ease of use. It is also important that support is supplied. Basic UTAUT is an adequate model to assess technology acceptance in a radiological setting.

Embolic stroke after unanticoagulated cardioversion despite prior exclusion of atrial thrombi by transoesophageal echocardiography.

Recent studies in patients with atrial fibrillation, not on anticoagulation, suggest that if transoesophageal echocardiography (TEE) excludes the presence of thrombi, early cardioversion can be performed safely without the need for anticoagulation before the procedure. Immediately after successful cardioversion, however, left atrium or left atrial appendage stunning may be present, potentially carrying a risk for de novo thrombus formation. Furthermore, the presence of spontaneous contrast is considered as a contraindication for unanticoagulated cardioversion since it has been associated with postcardioversion thromboembolism. We present a case in which stroke developed in relation to unanticoagulated cardioversion regardless of careful prior evaluation with TEE.

Exercise performance and diastolic filling in essential hypertension.

OBJECTIVES: To investigate the relationship between arterial blood pressure, left ventricular mass, diastolic filling and maximal exercise capacity in patients with newly diagnosed essential hypertension. DESIGN: Asymptomatic untreated patients with office blood pressure > 140/90 mmHg were studied prospectively after exclusion of associated disease. METHODS: Twenty consecutive white patients (14 male, 6 female; age 43 +/- 12 years) with office blood pressure 164 +/- 23/103 +/- 10 mmHg, mean 24-h ambulatory blood pressure 142 +/- 25/89 +/- 15 mmHg and normal systolic cardiac function underwent an echocardiographic examination to determine left ventricular mass and diastolic filling parameters and performed a bicycle ergometer test to determine maximal voluntary exercise capacity. RESULTS: In single regression analysis exercise time and maximal oxygen uptake were related to sex and age. A multiple regression showed that only age was related to exercise capacity, however. On subgroup analysis of male patients between 30 and 50 years (n = 10), exercise time (659 +/- 134 s) was significantly inversely related to mean 24-h ambulatory diastolic blood pressure (92 +/- 11 mmHg) (r = -0.67; p = 0.03) and positively to diastolic filling expressed as ratio of peak early to peak atrial filling velocity (Emax/Amax ratio; 1.34 +/- 0.40) (r = 0.65; p = 0.04) or as ratio of velocity time integral (VTI) of early filling phase to VTI of atrial filling phase (VTIE/VTIA ratio; 1.94 +/- 0.72) (r = 0.02). Maximal oxygen consumption (22.3 +/- 4.1 ml/kg/min) was significantly inversely correlated with mean 24-h ambulatory diastolic blood pressure (r = -0.67; p = 0.03), mean 24-h ambulatory systolic blood pressure (147 +/- 25 mmHg) (r = -0.82; p < 0.01), left ventricular mass (312 +/- 143 g) (r = -0.86; p < 0.01), left ventricular mass index (135 +/- 41 g/m2) (r = -0.76, p = 0.01) and positively with diastolic filling expressed as Emax/Amax ratio (r = 0.71; p = 0.02) or as VTIE/VTIA ratio (r = 0.70; p = 0.02). CONCLUSION: This study shows the important interrelation between blood pressure, cardiac mass, diastolic filling and exercise capacity. High blood pressure entrains a larger cardiac mass but slows cardiac filling and decreases exercise capacity.

Delayed restoration of atrial function after conversion of atrial flutter by pacing or electrical cardioversion.

It is often suggested but never proven that atrial function is not affected during atrial flutter, nor after its conversion to normal sinus rhythm. To evaluate this hypothesis, a prospective study was performed in 22 patients (age range 20 to 88 years) with atrial flutter. Diastolic transmitral flow was analyzed with echo-Doppler before and after conversion. After randomization, conversion was attempted with overdrive pacing or up to two 50 J shocks. If the initial method was unsuccessful, a 200 J shock was administered. All patients were converted to sinus rhythm with this protocol. Shortly after conversion (at 1 and 6 hours), atrial contribution to ventricular filling was absent in 4 of 22 patients. In the remaining 18 patients, atrial contribution to ventricular filling was small. Atrial contribution to transmitral flow improved from 20 to 27% within 24 hours (p < 0.01) and increased further to 38% at 6 weeks (p < 0.005). Peak velocity of late diastolic filling increased from 0.28 m/s after 1 hour to 0.39 m/s after 24 hours (p < 0.0001) and improved even further during later follow-up. In 1 patient, an effective atrial systole was not observed until the 14th day. Cardiac output did not change significantly during the study period. No differences were observed between the conversion modalities. In conclusion, atrial dysfunction is present immediately after conversion of atrial flutter to normal sinus rhythm. This dysfunction occurs also after overdrive pacing and can last > 1 week. The findings suggest that stasis in the atria can remain temporarily present after successful conversion of atrial flutter to sinus rhythm.

Cardiac anatomy and diastolic filling in professional road cyclists.

In the literature two divergent types of exercise-induced cardiac hypertrophy have been described: isotonic exercise induced eccentric hypertrophy with proportional increase in end-diastolic left ventricular dimension and wall thickness and isometric exercise induced concentric hypertrophy with normal end-diastolic left ventricular dimension but increased wall thickness. Using echocardiography, cardiac anatomy and diastolic filling were studied in 26 professional road cyclists. Compared to 21 control subjects, matched according to age, sex and morphometry the athletes had significantly larger left atrial dimension [41.3 (SD 4.8) vs 36.6 (SD 4.5) mm], left ventricular dimension [56.0 (SD 3.8) vs 53.2 (SD 4.7) mm], end-diastolic septum thickness [11.1 (SD 2.5) vs 8.4 (SD 1.9) mm], end-diastolic posterior wall thickness [11.6 (SD 2.2) vs 8.4 (SD 1.5) mm] and left ventricular mass index [170.4 (SD 40.6) vs 107.0 (SD 27.7) g.m-2]. We concluded that the hypertrophy in the road cyclists was of the mixed type (concentric-eccentric) with an increase in the internal dimension of the left ventricle and an even larger increase in the thickness of the ventricular walls. Diastolic filling however was similar in the athletes and control subjects. No correlations were found between the left ventricular mass index and diastolic filling parameters. We concluded therefore that professional road cycling causes mixed cardiac hypertrophy without diastolic filling abnormalities and can therefore be considered benign.

Right atrial invasive thymoma with protrusion through the tricuspid valve.

A patient with superior caval vein compression due to malignant thymoma with infrequent intracavitary cardiac growth is presented. Diagnostic accuracy of cardiac involvement was higher using transesophageal echocardiography compared to transthoracic echocardiography. The majority of the rare intracavitary cardiac thymomas seem to be confined to the right side of the heart.