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J A Paraskos

Publications and source records attributed to J A Paraskos.

16 recordsLinked to original sources

The innocent murmur.

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Diagnosis, Differential

Noninvasive evaluation of cardiac risk before elective vascular surgery.

The prognostic utility for predicting cardiac events was determined for dipyridamole-thallium scintigraphy, exercise stress testing (when possible; n = 69) and multiple clinical variables in 100 consecutive patients admitted for elective surgical repair of peripheral vascular disease. After initial noninvasive evaluation, 11 patients were referred for coronary angiography and the remaining 89 patients had surgery without further cardiac studies. Fifteen patients (17%) had a postoperative myocardial infarction, one of which was fatal. Of these 15 patients, 14 had thallium redistribution and 3 had positive ST segment depression during stress testing. Among the many variables tested, the presence of redistribution on serial dipyridamole-thallium images was the most significant predictor of serious cardiac events. All 11 patients who had coronary angiography had both redistribution and multivessel coronary artery disease. Four of these 11 patients died during follow-up and 6 had coronary artery bypass surgery. It is concluded that dipyridamole-thallium imaging has significant prognostic utility in predicting postoperative myocardial infarction and death in patients with severe peripheral vascular disease, and is superior to exercise testing or clinical variables in determining cardiac risk. The odds for a serious cardiac event were 23 times greater in a patient with thallium redistribution than in a patient without redistribution, strongly suggesting that myocardial imaging may be used as a primary screening test before elective vascular surgery.

Aged

Cardiovascular pharmacology. III: Atropine, calcium, calcium blockers, and beta-blockers.

Atropine, calcium, calcium-channel blockers, beta-adrenergic-receptor blockers, oxygen, morphine, vasodilators, and potent diuretics are frequently used in advanced cardiac life support (ACLS). Since the last AHA conference on ACLS standards, little controversy has arisen regarding the use of oxygen, morphine, vasodilators, or potent diuretics. In 1979, a full vagolytic dose of atropine was recommended for use early in the course of asystolic or bradycardiac arrest. Since then reports suggest that this higher dose of atropine may be of some limited value in treating this highly resistant form of arrest. The routine use of calcium for asystole, bradycardiac arrest, and electromechanical dissociation has come under intense scrutiny. Studies have failed to demonstrate improved survival and have found potentially deleterious levels of serum calcium when calcium was administered according to AHA standards. It is also possible that postanoxic cerebral injury is exacerbated by the use of calcium. No controversy exists, however, concerning the use of calcium for the moribund patient with possible hypocalcemia or with an excess of calcium-channel blockers. The use of calcium-channel blockers has been advocated to prevent or retard the intracellular accumulation of calcium, which may cause irreversible postanoxic tissue damage. Calcium-channel blockers may also be useful in preventing or decreasing cerebral and coronary arteriospasm. These drugs have antianginal properties that may decrease ischemia. The antiarrhythmic effect of verapamil is particularly useful in the treatment of uncomplicated paroxysmal supraventricular tachycardia. Verapamil and diltiazem slow conduction through the atrioventricular node and may be used to slow the ventricular response in atrial fibrillation and flutter.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists

External compression without adjuncts.

Over the past decade many exciting and promising new approaches of delivering CPR have been studied. Considerable data have accumulated suggesting that forward flow during CPR is generated, at least in part, by the development of elevated intrathoracic pressure with an extrathoracic arteriovenous pressure difference. This mechanism, known as the "thoracic pump," has been documented during "cough-CPR" and has led to numerous attempts at optimizing the outcome by increasing intrathoracic pressure in CPR. Studies have demonstrated improved flows with simultaneous ventilation and sternal compression, with static or interposed abdominal compression, with longer duration compression, and with various combinations of these maneuvers. Other recent studies have suggested that the cardiac compression mechanism may indeed be operative, at least under certain circumstances, and that CPR may be optimized by increasing the force and rate of compression. Still others have advocated a simple change in the sequence of initiating ventilation and compression. Which, if any, of these newly advocated methods improve the outcome when applied to man remains to be established. If any of these techniques is shown to be more advantageous, its widespead use will depend on its applicability without adjuncts and its teachability to the lay public.

Heart Massage

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

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

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