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L S Goodenday

Publications and source records attributed to L S Goodenday.

13 recordsLinked to original sources
PubMed2001

Knowledge discovery approach to automated cardiac SPECT diagnosis.

The paper describes a computerized process of myocardial perfusion diagnosis from cardiac single proton emission computed tomography (SPECT) images using data mining and knowledge discovery approach. We use a six-step knowledge discovery process. A database consisting of 267 cleaned patient SPECT images (about 3000 2D images), accompanied by clinical information and physician interpretation was created first. Then, a new user-friendly algorithm for computerizing the diagnostic process was designed and implemented. SPECT images were processed to extract a set of features, and then explicit rules were generated, using inductive machine learning and heuristic approaches to mimic cardiologist's diagnosis. The system is able to provide a set of computer diagnoses for cardiac SPECT studies, and can be used as a diagnostic tool by a cardiologist. The achieved results are encouraging because of the high correctness of diagnoses.

Artificial Intelligence↗
PubMed1996

A neuro-fuzzy algorithm for diagnosis of coronary artery stenosis.

In this paper a method of fuzzy decision making applied to diagnosis of coronary artery stenosis is presented. The method uses a neural network approach for the diagnosis of stenosis in the three main coronary arteries (left anterior descending, right coronary artery, and circumflex). First, the knowledge base domain, 201Tl scintigram training data, is explained and the method of preprocessing the original heart images is given. Next, the method of dealing with the uncertainties present in the data using the fuzzy approach is outlined. Finally, the algorithm and the results are discussed and compared with other approaches.

Algorithms↗
PubMed1990

An expert system for diagnosis of coronary artery stenosis based on 201Tl scintigrams using the Dempster-Shafer theory of evidence.

An expert system for the diagnosis of stenoses in the three main coronary arteries (left anterior descending, right coronary artery and circumflex) is described. First, the knowledge base domain--201Tl scintigrams--is explained and the method of preprocessing the original heart images is given. Next, the method of dealing with the uncertainties present both in the cardiologist-specified rules and the data using the Dempster-Shafer theory of evidence is explained. Finally, the constructed expert system and the results are discussed and several graphical examples are shown.

Coronary Disease↗
PubMed1987

Alterations in left ventricular diastolic function with doxorubicin therapy.

To determine whether impaired diastolic function may be an early sign of doxorubicin cardiotoxicity, a retrospective study was performed in 12 patients who had undergone serial radionuclide angiography and were found to have a left ventricular ejection fraction of 55% or more before doxorubicin (Adriamycin) treatment and during follow-up. Average rapid filling velocity and slow filling velocity were both significantly reduced after doxorubicin treatment. Rapid filling velocity decreased from 5.17 +/- 1.52 to 4.18 +/- 0.96 units/s (p less than 0.01), and slow filling velocity decreased from 2.20 +/- 1.32 to 1.42 +/- 0.62 units/s (p less than 0.05). There were no significant changes in filling volume ratio, total diastolic time or diastolic time ratio. Because a change in left ventricular diastolic function can occur before ejection fraction falls to subnormal levels, diastolic function as well as systolic function should be examined for the early detection of doxorubicin cardiotoxicity. The clinical implications of our observations can only be established by a longer-term prospective analysis of left ventricular function in patients receiving doxorubicin therapy.

Adolescent↗
PubMed1984

Hyponatremia in patients treated with lorcainide, a new antiarrhythmic drug.

The effects of lorcainide, a new antiarrhythmic drug, on serum electrolytes and osmolality are described in a series of 33 patients with organic heart disease and complex ventricular arrhythmias treated with lorcainide. In eight patients, a mean decrease in serum Na+ of 8.25 +/- 3.2 mEq/L was observed after a single 200 mg intravenous dose of lorcainide. Sixteen of 33 patients developed significant hyponatremia and hypoosmolality during oral treatment with lorcainide. In all except two patients, serum Na+ returned to normal values within 3 to 12 months of continued lorcainide therapy. Low serum Na+ and hypoosmolality in the absence of volume depletion, clinically manifest edema, and unaltered renal, adrenal, cardiac, or thyroid function suggest that this antiarrhythmic drug produced the syndrome of inappropriate antidiuretic hormone secretion (SIADH). SIADH appeared to be transient and asymptomatic in our patients. One patient developed severe hyponatremia with serum Na+ of 108 mEq/L when hydrochlorothiazide was given to control hypertension. It is concluded that SIADH is an important side effect of lorcainide therapy. We recommend that serum Na+ be carefully monitored in patients started on lorcainide therapy, and extreme caution should be exercised in prescribing diuretics to patients with persistent hyponatremia.

Adult↗
PubMed1983

Scintigraphic detection of ventricular aneurysm with thallium-201.

We present two patients who exhibited striking abnormalities on stress thallium-201 scintigrams, suggesting ventricular aneurysm before documentation of this diagnosis by contrast ventriculography. The features of the scintigrams included: (a) a large perfusion defect overlying the cavity of the left ventricle, the defect extending to the periphery of the cardiac image and containing fewer counts than the lung background; (b) relatively increased lung background; (c) increased right-ventricular prominence; and (d) abnormal cardiac contour. Although large aneurysms of the left ventricle can usually be diagnosed from history and physical examination, occasionally they can be more subtle in their manifestations. Appearance of a myocardial perfusion image as described above should alert the physician to the possibility of this diagnosis.

Adult↗
PubMed1976

Noninvasive measurement of cardiac function during exercise, using resaturation curves.

The resaturation curve, a noninvasive indicator-dilution test using an ear oximeter to detect rates of change in arterial oxygen saturation during breathing of various concentrations of oxygen, was used to assess cardiac performance in normal subjects and in 108 patients with cardiac valvular disease. Measurements made during exercise included the time constant of resaturation (tau) and beat-to-beat changes in arterial oxygen saturation (the left heart clearance fraction). At maximum rates of voluntary work, patients had a significantly reduced clearance fraction and longer tau than normal subjects. Clearance fraction and tau improved in patients after aortic valve replacement; deterioration occurred in tau and clearance fraction over time in patients treated medically, as compared to normal subjects who showed little change during a ten-year period. Clearance fraction and tau correlated with hemodynamic data obtained during cardiac catheterization. The resaturation curve provides an objective measure of cardiac impairment that can be readily repeated during follow-up of patients with heart disease.

Adult↗
PubMed1970

Abnormal distribution of pulmonary blood flow in aortic valve disease. Relation between pulmonary function and chest radiograph.

Wasted ventilatory volume (V(D)) and its ratio to tidal volume (V(D)/V(T)) were measured at rest and during exertion in 17 patients with aortic valve disease. We considered V(D)/V(T) to indicate abnormal ventilation: perfusion relations if it did not decrease on exertion, or if the exercising value was greater than 40 per cent. Plain chest radiographs were independently examined for evidence of diversion of pulmonary blood to the upper lobes. There was significant agreement (p<0.05) between radiographic and pulmonary function estimations of abnormality. This suggests that the raised pulmonary venous pressure associated with left ventricular failure creates an abnormal pattern of blood flow through the lung, which is responsible for causing inadequate perfusion with respect to ventilation.

Aortic Valve Insufficiency↗