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Biomedical subjects

M J Sands

Publications and source records attributed to M J Sands.

At least 37 records · Page 2Linked to original sources
PubMed1983

Gold-195m for serial first pass radionuclide angiocardiography during upright exercise in patients with coronary artery disease.

Sequential first pass radionuclide angiocardiography can be performed in rapid succession using gold-195m because of its low radiation dose and short half-life (30.5 seconds). In 25 patients with known or suspected coronary artery disease, first pass studies with gold-195m were obtained using a computerized multicrystal gamma camera at rest (n = 29), at the end of each 3 minute stage of exercise (n = 25) and immediately after exercise (n = 23). In 13 patients, assessment of left ventricular function during exercise with gold-195m was combined with thallium-201 stress scintigraphy. Left ventricular ejection fraction at rest assessed with technetium-99m and gold-195m correlated well (r = 0.93). In addition, repeat left ventricular ejection fractions at rest with gold-195m correlated closely (r = 0.96). Comparing peak exercise left ventricular ejection fraction with ejection fraction at rest, abnormal left ventricular reserve was found in 20 of 25 patients. Various abnormal patterns of left ventricular ejection fraction response were noted, showing the diagnostic potential of serial exercise angiocardiography. Thallium-201 myocardial images, obtained on a single crystal gamma camera after multiple gold-195m injections, were all of good diagnostic quality and were abnormal in 10 of 13 patients. Thus, multiple high count rate first pass studies can be obtained with gold-195m during and after exercise, allowing serial study of physiologic changes in left ventricular function during exercise. Thallium-201 myocardial imaging can be performed using the same exercise test, providing direct comparison of myocardial function and perfusion.

Adult↗
PubMed1982

Radionuclide angiographic exercise left ventricular performance in chronic aortic regurgitation: relationship to resting echographic ventricular dimensions and systolic wall stress index.

Forty-five patients with chronic aortic regurgitation (AR) underwent first-pass radionuclide angiocardiography (RNA) at rest and during upright bicycle exercise, as well as M-mode echocardiography at rest. Abnormal left ventricular (LV) exercise reserve, defined by the absolute change in ejection fraction (EF), was present in 16 of 45 patients (36%). Seven of ten patients with abnormal resting EF (less than 50%) and three of seven symptomatic patients had normal LV exercise responses. Patients with normal LV exercise reserve by RNA had LV dimensions by echo at end diastole (5.9 +/- 0.2 vs 6.5 +/- 0.3 cm, p = NS) and end systole (3.9 +/- 0.2 vs 4.4 +/- 0.3 cm, p = NS) comparable to those in patients wht abnormal LV exercise reserve. However, the mean corrected LV end-diastolic (LVED) radius/wall thickness ratio was significantly greater in AR patients with abnormal LV exercise reserve than in those with normal LV exercise reserve (395 +/- 15 vs 315 +/- 16, p less than 0.01). There data suggest that resting echocardiographic LV dimensions as well as the corrected echo LVED radius/wall thickness ratio have a variable relationship to RNA LV exercise performance in patients with chronic AR.

Adolescent↗
PubMed1982

Progressive heart failure and death associated with Mycoplasma pneumoniae pneumonia.

A case of progressive CHF and death associated with serologically confirmed Mycoplasma pneumoniae pneumonia in a previously healthy man is described. The association between the organism and significant cardiac or pericardial dysfunction discussed, the literature reviewed, and speculation made as to the underlying pathophysiologic mechanisms.

Adult↗
PubMed1981

Exercise left ventricular performance in patients with chest pain, ischemic-appearing exercise electrocardiograms, and angiographically normal coronary arteries.

Left ventricular performance was evaluated using first-pass radionuclide angiocardiography in 31 patients with chest pain, an ischemic-appearing exercise electrocardiogram, and angiographically normal coronary arteries at rest and during maximal upright bicycle exercise. Thallium-201 (201 TI) imaging was done in all patients after treadmill exercise and in selected patients after ergonovine provocation. Resting left ventricular performance was normal in all patients. An abnormal ejection fraction response to exercise was detected in 12 of 31 patients. Regional dysfunction was present during exercise in four patients, all of whom also had abnormal global responses. Three of these 12 patients and two additional patients had exercise-induced 201 TI perfusion defects. In all nine patients who underwent ergonovine testing, there was no suggestion of coronary arterial spasm. Thus, left ventricular dysfunction during exercise, in the presence of normal resting performance, was found in a substantial number of patients with chest pain, an ischemic-appearing exercise electrocardiogram, and normal coronary arteries.

Adult↗
PubMed1980

Longevity comparisons among lithium anode power cells for cardiac pacemakers.

Of over 10,000 lithium-powered pacemakers followed by a commercial transtelephone monitoring service, 148 have been explanted due to rate decline. A breakdown according to the power cell manufactures shows that the longevity is not uniform, indicating that significant differences exist among the power cell designs even though all have lithium anodes. One tenth of all lithium-powered pacemakers in the study were explanted for rate declines within 4 years.

Data Collection↗
PubMed1977

Pericarditis and perimyocarditis associated with active Mycoplasma pneumoniae infection.

In 13 patients an association existed from 1970-73 between Mycoplasma pneumoniae infection and acute pericarditis (in eight) or perimyocarditis (in five). In 12 patients the association was moderately probable, with a fourfold rise in complement-fixing antibody titers between acute and convalescent phase sera being noted. In the last patient, a lesser-order association was found using only convalsecent phase serum. The presence of influenza, herpes simplex, Coxsackie B, or adenovirus was excluded by serologic testing. Acute illness was variable, with four patients developing heart failure. Long-term evaluation (mean, 47 months) found eight patients asymptomatic and three symptomatic. Two patients died. Residual effects of the Mycoplasma infection seemed at least partially responsible in one compromised patient and in one who died. Mycoplasma infection should be considered in the presence of acute cardiovascular decompensation, especially when preceded by upper respiratory infection, and added to the possible causes of idiopathic cardiomyopathy.

Acute Disease↗
PubMed1975

The evaluation of left ventricular function in man. A comparison of methods.

Comparisons of the sensitivities of parameters for assessing left ventricular performance in man were made in 38 patients. The parameters compared were the ejection fraction, ventriculographic contraction patterns, the left ventricular end-diastolic pressure, and the contractile indices including the contractile element velocity at 10 mm Hg (Vce 10) and maximal contractile element velocity (Vmax). The contractile indices were obtained by catheter tip manometry, utilizing developed pressure (DP) to calculate the velocity of contractile element shortening (Vce) from the formula: dp/dt divided by 32 DP. Vce 10 was measured directly and Vmax was derived by linear manual extrapolation of the pressure-velocity plot to 0 mm Hg. Vmax values derived from linear manual extrapolation were compared with values obtained by computer least squares fitting of the Vce and developed pressure data points to single and double exponential equations. The Vce and developed pressure data points fit the single exponential equation better than the double exponential equation but the use of either equation resulted in slightly higher values for Vmax than obtained with linear manual extrapolation. The effect of heart rate on myocardial contractility was eliminated by making comparisons at both a basal and atrial paced rate of 100. Utilizing all methods, 24 patients were identified to have ventricular dysfunction. The contractile indices were significantly less sensitive than any other parameter (P smaller than 0.05) and identified seven patients while the left ventricular end-diastolic pressure, ejection fraction, and presence of asynergy identified 15, 15, and 12 patients, respectively. The use of a common atrial paced rate of 100 did not increase the sensitivity of the contractile indices. Since there was only partial overlapping between parameters in the identification of left ventricular dysfunction, the combination of different parameters was more sensitive than any single parameter alone. It is concluded that several methods are required to identify all patients with left ventricular dysfunction and that the contractile indices are the least sensitive indicator of left ventricular dysfunction.

Blood Pressure Determination↗
PubMed1975

Hypoglycemia complicating the use of solution of glucose, insulin and potassium.

A patient is described who developed hypoglycemia and generalized neurologic depression after cardiac surgery, while receiving an infusion of glucose, insulin, and potassium (GIK). Hypoglycemia as a complication of the use of GIK solution in patients with hepatic dysfunction, malnutrition and low cardiac output is discussed.

Cardiac Catheterization↗