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Biomedical subjects

J M Atkins

Publications and source records attributed to J M Atkins.

49 records · Page 3Linked to original sources
PubMed1975

The diving reflex used to treat paroxysmal atrial tachycardia.

Induction of the diving reflex, by immersion of the face in cold water (2 degrees C) while the breath was held, converted paroxysmal atrial tachycardia to sinus rhythm within 15-35 seconds in seven patients (aged 22-66). Four had histories of heart attacks that had previously required vasopressor therapy, and two had been digitalised; three had no history of prior paroxysmal atrial tachycardia or heart-disease. The reported procedure, which is convenient, non-invasive, and can be self administered by the patient after brief instruction, may offer a useful adjunct to carotid-sinus massage and intravenous infusion of vasopressors for the treatment of paroxysmal atrial tachycardia.

Adult↗
PubMed1975

Left ventricular dynamics during recovery from exercise.

Left ventricular dynamics during recovery were measured in dogs, 3 min after brief periods of mild, moderate, and severe treadmill exercise. As compared with resting values, stroke volume was unchanged, and the maximum first derivative of the left ventricular pressure was either unchanged or slightly elevated. Increases in heart rate of 20, 26, and 46 beats/min for mild, moderate, and severe exercise appear to be the major factor in augmenting cardiac output during recovery. With moderate and severe exercise, left ventricular end-diastolic diameter increased and continued to be elevated during recovery, whereas end-systolic diameter decreased during exercise but was elevated above resting values during recovery. Therefore, with strenuous exercise, a sympathetic-mediated increase in contractility recedes promptly during the postexercise period but the Frank-Starling mechanism continues to be a factor.

Animals↗
PubMed1975

Technetium stannous pyrophosphate myocardial scintigrams in patients with chest pain of varying etiology.

Technetium-99m stannous pyrophosphate was utilized for myocardial imaging in 202 patients admitted to the hospital with chest pain of uncertain etiology. One hundred and one patients had clinical and evolved electrocardiographic and enzymatic evidence of acute myocardial infarction. Ninety-six of these 101 patients had increased myocardial uptake of the technetium stannous pyrophosphate and positive myocardial scintigrams; there was nearly precise correlation between the ECG and myocardial imaging localization of the area of infarction for acute transmural myocardial infarctions. In the five patients with negative myocardial images the scintigrams were obtained after seven or more days had elapsed following the myocardial infarction. In the remaining 101 patients no clinical, ECG, or enzymatic evidence of infarction developed; 92 of these patients had negative myocardial scintigrams. Seven of the remaining nine patients were admitted with "unstable angina pectoris", and despite the absence of diagnostic ECG and enzyme evolution each of these patients had faintly and diffusely positive myocardial scintigrams. The remaining two patients had positive myocardial scintigrams but no definite ECG or enzymatic evidence of acute myocardial infarction. Thus the technetium pyrophosphate imaging technique appears safe, inexpensive and to correlate well with ECG and enzyme identification of the presence of infarction and with ECG localization of myocardial infarction. In addition the positive myocardial scintigrams in some patients with "unstable angina" suggest that there may be limited myocardial necrosis that is ordinarily undetected by ECG and enzymes in these patients. The incidence of false positive and false negative scintigrams appears to be small.

Angina Pectoris↗
PubMed1975

Influence of hypertonic mannitol on ventricular performance and coronary blood flow in patients.

The influence of a relatively small increase in serum osmolality produced by hypertonic mannitol on ventricular and systemic arterial hemodynamics and coronary blood flow was studied in 20 patients undergoing cardiac catheterization. Mannitol given to increase serum osmolality 10 mOsm resulted in a small but significant increase in mean systemic arterial pressure, maximum LV dp/dt, left ventricular end-diastolic pressure and cardiac output but no significant change in heart rate or hematocrit. The most prominent change in the patients studied, however, was in coronary blood flow which increased 39% after mannitol. Patients with severe two and three vessel coronary artery disease had increased in coronary blood flow similar to those in patients without coronary artery disease. The data suggest the need to further evaluate the physiological importance of the increase in coronary blood flow produced by mannitol in patients with coronary artery disease and indicate the possibility that mannitol might be of value in treating certain problems in patients with coronary artery disease,

Blood Pressure↗
PubMedDate not supplied

Hyperphosphatemia from lipid emulsion in a patient on total parenteral nutrition.

The clinical course of a patient is described in whom hyperphosphatemia occurred on total parenteral nutrition with lipid emulsion providing half of the nonnitrogenous caloric support. Renal insufficiency, hypoparathyroidism, pseudohypoparathyroidism, and severe catabolism are excluded as causes of this hyperphosphatemia. Changes in serum phosphate are attributed to metabolism of phospholipid present in the lipid emulsion, the sole phosphate source in this patient. These observations suggest that the phosphate of phospholipids can contribute significantly to the metabolic pool of inorganic phosphate. Lipid emulsion, most commonly thought of as a major caloric source, should not be neglected when one is confronted with hyperphosphatemia during total parenteral nutrition.

Fat Emulsions, Intravenous↗