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Biomedical subjects

J A Paraskos

Publications and source records attributed to J A Paraskos.

32 records · Page 2Linked to original sources
PubMed1979

Assessment of operative risk with electrocardiographic exercise testing in patients with peripheral vascular disease.

Doppler ankle blood pressures were performed inere obtained in 100 consecutive patients with peripheral arterial insufficiency after treadmill exercise. A twelve lead electrocardiogram was monitored during and after exercise. Despite a restricted ability to exercise because of peripheral vascular insufficiency, forty-six patients had ventricular dysrhythmia or ischemia, or both, usually without associated symptoms. Electrocardiographic monitoring during treadmill exercise proved a useful predictor of postoperative complications. Thirty-two vascular operations were performed in patients with no electrocardiographic evidence of ischemia. No patient had a postoperative myocardial infarction or died. Sixteen vascular procedures were performed in patients with ischemic responses on exercise electrocardiography. Six patients had postoperative myocardial infarctions, two of which were fatal. Electrocardiographic monitoring during treadmill exercise for peripheral vascular insufficiency in recommended (1) to assess the severity of coronary artery disease and the likehood of postoperative complications, and (2) as a precautionary measure to identify potentially dangerous dysrhthmias or ischemia during exercise before the development of clinical symptoms.

Aged↗
PubMed1979

Fatal pulmonary hemorrhage after use of the flow-directed balloon-tipped catheter.

The flow-directed balloon-tipped catheter is extensively used in intensive care units, catheterization laboratories, operating rooms, and emergency wards. Major complications associated with its use have not been frequently reported. In a recent 2-year period in four hospitals, we identified five cases of fatal pulmonary hemorrhage resulting from balloon-tipped catheters. We review here four additional cases previously cited in the literature and discuss possible mechanisms and predisposing factors associated with this complication and guidelines for safe use of these catheters. Pulmonary artery rupture is probably commoner than previously reported.

Adult↗
PubMed1977

Pulmonary embolism, pulmonary hemorrhage and pulmonary infarction.

We compared 41 patients with angiographic proof of pulmonary embolism and clinical signs of pulmonary infarction (as evidenced by an infiltrate on x-ray study and pleuritic pain in the area of the embolus) with 24 patients with pulmonary embolism but without infarction. Only 18 of the 41 patients with pulmonary infarction had associated heart disease. Pulmonary infarction was uncommon when emboli obstructed central arteries but frequent when distal arteries were occluded. Follow-up x-ray examination showed that the infiltrates resolved in the patients with pulmonary infarction without heart disease, but persisted when heart disease was present. We suggest that obstruction of distal arteries results in pulmonary hemorrhage owing to an influx of bronchial arterial blood at systemic pressure. Hemorrhage causes symptoms and x-ray changes usually attributed to pulmonary infarction. However, hemorrhage resolves without infarction in patients without, but progresses to infarction in those with, heart disease.

Angiography↗
PubMedDate not supplied

Studies of systolic mechanics and diastolic behavior of the left ventricle in the trained racing greyhound.

Despite much interest in the effects of exercise on the myocardium, and the need to develop animal models which mimic conditions leading to cardiac hypertrophy, little attention has been focused on the trained racing greyhound. The current study compared two groups of anesthetized trained racing greyhounds (a total of 20 animals, 12 of whom were maintained for serial studies and 8 of whom were sacrificed for anatomic correlations) with 3 detrained greyhounds and 6 comparably sized mongrels. Systemic blood pressures, right and left heart pressures, ventricular mechanics and indices of diastolic behavior were compared. All measured indices of contractility (dp/dt, dp/dtDP40, Vce and Vmax) were lower in trained racing greyhounds than in mongrels although none achieved statistical significance. No significant difference in diastolic behavior was found between trained greyhounds and mongrels. While caution should be applied because of the small numbers of animals and the use of anesthesia, the lower than expected contractility found in trained racing greyhounds may reflect increased parasympathetic tone in the immediate post-training period. The normal diastolic behavior of the trained greyhound left ventricle contrasts to abnormal diastolic behavior found in models of chronic pressure overload.

Animals↗
PubMedDate not supplied

Effects of the cessation of training on left ventricular function in the racing greyhound. Serial studies in a model of cardiac hypertrophy.

Exercise-induced cardiac hypertrophy has been associated with normal resting left ventricular function and, after cessation of training, variable degrees of regression. The racing greyhound is an animal with cardiac hypertrophy said to be part congenital and part exercise-induced. Racing greyhounds underwent serial cardiac catheterization three times during an 8-month period after cessation of racing/training to determine the functional consequences of the cessation of training. At the end of 8 months of inactivity the animals' hearts were excised and weighed in order to compare heart weight/body weight (HW/BW) ratios with those obtained in a group of racing greyhounds killed within one month, 19 +/- 16 days (mean +/- SD), of the cessation of training. Comparison of HW/BW ratios failed to reveal a significant difference between the serially studied group, 12.1 +/- 1.9 g/kg (mean +/- SD), and the more recently exercising group, 12.7 +/- 1.4 g/kg (mean +/- SD) of dogs. After 2 months of inactivity, 9 of 12 greyhounds in the serially studied group showed increases in max dP/dt and dP/dt normalized to a pressure of 50 mmHg. Modified pre-ejection period and peak negative dP/dt also increased significantly (p less than .004) during this same period. No further changes in these variables were found at the final 8-month study. Our failure to demonstrate a difference in HW/BW ratios between these two groups of dogs suggests that the exercise-induced component of cardiac hypertrophy in the trained racing greyhound is probably very small and, if it exists, regresses very early (less than 1 month). Changes in contractility indices that were observed occurred after this time period (between 1 and 2 months) and are therefore probably not due to regression of cardiac hypertrophy.

Animals↗