Quantitative assessment of the presence of a single leg separation in Björk-Shiley convexoconcave prosthetic heart valves.

RATIONALE AND OBJECTIVES: The authors developed an analytic software package for the objective and reproducible assessment of a single leg separation (SLS) in the outlet strut of Björk-Shiley convexoconcave (BSCC) prosthetic heart valves. METHODS: The radiographic cinefilm recordings of 18 phantom valves (12 intact and 6 SLS) and of 43 patient valves were acquired. After digitization of regions of interest in a cineframe, several processing steps were carried out to obtain a one-dimensional corrected and averaged density profile along the central axis of each strut leg. To characterize the degree of possible separation, two quantitative measures were introduced: the normalized pit depth (NPD) and the depth-sigma ratio (DSR). The group of 43 patient studies was divided into a learning set (25 patients) and a test set (18 patients). RESULTS: All phantom valves with an SLS were detected (sensitivity, 100%) at a specificity of 100%. The threshold values for the NPD and the DSR to decide whether a fracture was present or not were 3.6 and 2.5, respectively. On the basis of the visual interpretations of the 25 patient studies (learning set) by an expert panel, it was concluded that none of the patients had an SLS. To achieve a 100% specificity by quantitative analysis, the threshold values for the NPD and the DSR were set at 5.8 and 2.5, respectively, for the patient data. Based on these threshold values, the analysis of patient data from the test set resulted in one false-negative detection and three false-positive detections. CONCLUSIONS: An analytic software package for the detection of an SLS was developed. Phantom data showed excellent sensitivity (100%) and specificity (100%). Further research and software development is needed to increase the sensitivity and specificity for patient data.

Noninvasive long-term follow-up after coarctation repair.

Thirty patients operated on for aortic coarctation while less than 3 years of age underwent magnetic resonance imaging, digital subtraction angiography, and bicycle exercise testing 14 to 33 years (mean, 22 years) after operation. Diameters of the aorta at the site of the anastomosis, of the distal arch, and of the aorta at the level of the diaphragm were measured in the images. Blood pressures were obtained from the right arm and leg before and after exercise. Patients were divided into three groups according to blood pressure data: group I, resting gradient less than 30 mm Hg and exercise gradient less than 50 mm Hg; group II, resting gradient less than 30 mm Hg and exercise gradient greater than 50 mm Hg; and group III, resting gradient 30 mm Hg or greater. A control group underwent the same test. The frequency of hypertensive patients was greater in groups II (58%) and III (100%) than in group I (20%). The anastomosis/descending aorta ratio seen in digital subtraction angiograms was smaller in group II and III patients. Exercise blood pressure gradient correlated significantly (r = -0.48; p = 0.009) with anastomosis/descending aorta ratio in digital subtraction angiograms but not in magnetic resonance images. Twenty of 30 patients (67%) had a significant anatomic narrowing at the site of the anastomosis. Blood pressure data correlated with diameters measured in digital subtraction angiograms but not with diameters measured in magnetic resonance images.

Medical, social and psychological recovery after cardiac rehabilitation.

A multidisciplinary study was undertaken to determine the number of patients that recovered, deteriorated or remained unchanged during a cardiac rehabilitation programme, as assessed in medical, social and psychological terms. In addition, the relationship between the medical, social and psychological aspects of recovery were investigated. Criteria for improvement, deterioration and an unchanged condition had been developed for the different aspects of recovery. These criteria were based on the degree of change during the rehabilitation programme (expressed in an effect size index) and the outcome at completion of the programme (expressed in terms of good, moderate or poor according to external standards). Although more patients improved than deteriorated, quite a few patients remained unchanged in medical, social or psychological condition. We conclude that cardiac rehabilitation might not be necessary for some patients and is not sufficient for others. Further, the relationship between the several aspects of recovery investigated was found to be weak.

Work resumption and leisure activities after cardiac rehabilitation: the development of criteria to measure social recovery.

In a multicentered trial, the authors investigated 280 cardiac patients to determine the level of recovery of their social life after they had completed a physical training program. Data on work and leisure activities (sports, hobbies, social contacts, and odd jobs) were obtained immediately before and after rehabilitation and again 12 months later by means of semistructured interviews and an inventory of leisure activities. For the analysis of leisure variables, they developed a classification procedure to assign patients to one of five categories indicating an unchanged good outcome, significant recovery, nonparticipation, significant deterioration, or an unchanged poor outcome. The results after rehabilitation showed that some patients had benefited more than others. In addition, improvement or deterioration in one aspect of social recovery appeared to be independent from other aspects. Further systematic research is needed to determine which factors influence the amount of benefit derived from rehabilitation.

Predictors of physical activity one year after myocardial infarction.

A number of factors predicting habitual physical activity, duration of night's rest, return to work and exercise tolerance one year after acute myocardial infarction (AMI) are studied in fifty-five male patients. Except for exercise tolerance three months after AMI, the results of this prospective study suggest that psychologic factors are more important predictors of the four outcome variables than angina pectoris, infarction size and participation in a physical training program. The most important predictor appears to be the patient's subjective opinion of his physical capabilities, measured by the perceived exercise tolerance scale. The expectation of the eventual return to work three months after MI plays also a significant role as a predictor. Both are predictors of the exercise tolerance and return to work one year after AMI. These findings suggest that physical activity--defined as exercise tolerance, habitual physical activity and duration of night's rest--and return to work are closely related.

Anastomotic pseudoaneurysm after aorto-coronary bypass grafting.

A patient with a pseudoaneurysm at the site of the distal anastomosis of a saphenous vein coronary bypass graft is described. The aneurysm was resected. To our knowledge this is the first report of this complication after coronary bypass surgery.

The potential of simple clinical information and electrocardiogram to predict mortality of primary elective abdominal aortic reconstruction.

OBJECTIVE: To assess the importance of simple clinical information to predict mortality after primary elective aortic reconstruction. DESIGN: Retrospective clinical study. MATERIALS: Four hundred-three consecutive patients (206 with aortic occlusive disease (51%) and 197 with aneurysmal disease of the abdominal aorta (49%) who underwent primary elective aortic reconstruction during an 8 year study period. METHODS: Eight potential clinical risk variables and six electrocardiogram related risk variables were studied. The predictive value for postoperative mortality was evaluated univariately for all separate variables by calculation of the odds ratio (OR). Determination of the most predictive sets of risk factors was performed by stepwise logistic regression. RESULTS: Five clinical risk factors showed significant odds ratio's: > 70 years (OR: 4.1), aortic aneurysm (OR: 9.0), myocardial infarction (OR: 8.6), angina pectoris (OR: 4.6), congestive heart failure (OR: 8.1), all p < 0.01. Furthermore, four electrocardiogram related factors showed significant odds ratio's: infarction pattern (OR: 4.3, p = 0.003), ischaemic changes (OR: 6.2, p < 0.001), conductance disturbances (OR: 3.2, p = 0.04), and non-sinus rhythm (OR: 6.2, p = 0.003). Stepwise logistic regression analysis demonstrated that 3 clinical risk factors (aneurysm (OR: 6.1, p = 0.02), myocardial infarction (OR: 3.7, p = 0.01), and congestive heart failure (OR: 5.3, p = 0.006)) contributed significantly to mortality. Addition of any of the electrocardiogram risk factors did not contribute to the prediction of mortality in the presence of these factors. CONCLUSIONS: The patients' history and clinical examination provides the most useful information for further selection of additional cardiac tests before elective primary aortic reconstruction. The additional value of the electrodiogram is somewhat overestimated.

Evaluation of the Penàz servo-plethysmo-manometer for the continuous, non-invasive measurement of finger blood pressure.

Blood pressure in the finger was measured by a servo-plethysmomanometer constructed after the design of Penàz, which uses the principle of the unloaded arterial wall. The device contains a photoelectric plethysmograph mounted in an inflatable cuff and an electro-pneumatic transducer to control air pressure in the cuff via a servosystem. Comparison of simultaneous measurements of intra-arterial pressure in the brachial artery was performed on 33 patients suspected of having hypertension. In 12 patients evaluation of the technique could not be carried out due to technical failures or distorted blood pressure wave forms. Results of the remaining 21 patients show a mean underestimation of intra-arterial blood pressure by finger cuff blood pressure of 0.8 kPa (6 mm Hg), both for systolic and diastolic levels. The scatter range of the difference is from 1.9 to -3.5 kPa for systolic and 0.1 to -2.5 kPa for diastolic values. It appears that, although not all technical problems are solved, the Penàz servo-plethysmo-manometer is potentially an elegant method by which to arrive at the fully calibrated wave form of blood pressure in a finger in a non-invasive and continuous fashion.