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Biomedical subjects

S A Kane

Publications and source records attributed to S A Kane.

41 records · Page 3Linked to original sources
PubMed1982

Changes in pulmonary blood volume during upright exercise. Clinical implications.

Forty patients with coronary artery disease and 12 normal subjects underwent symptom-limited upright exercise. The pulmonary blood volume was measured by first-pass radionuclide angiography. There was no significant change in pulmonary blood volume during exercise in the normal subjects. Twenty-seven patients (68 percent) with coronary artery disease had an increase in pulmonary blood volume during exercise. Seventeen of the 19 patients (89 percent) with coronary artery disease who stopped the exercise because of shortness of breath had an increase in pulmonary blood volume during exercise compared with ten of 21 patients (48 percent) who stopped because of angina or an abnormal exercise ECG or both (P less than 0.02). We concluded that an increase in pulmonary blood volume was seen in 68 percent of our patients with coronary artery disease. The change in pulmonary blood volume was affected by the exercise end-points.

Adult↗
PubMed1981

Quantitative radionuclide angiography in assessment of hemodynamic changes during upright exercise: observations in normal subjects, patient with coronary artery disease and patients with aortic regurgitation.

Quantitative radionuclide angiography (with the first pass technique and a computerized multicrystal camera) was used to evaluate hemodynamic changes in three subject groups during symptom-limited upright exercise. The 12 normal subjects had significant increases in heart rate, stroke volume, left ventricular ejection fraction and cardiac output during exercise; changes in end-diastolic and end-systolic volumes were not significant. In the 24 patients with coronary artery disease there were significant increases in heart rate and cardiac output during exercise, but insignificant changes in end-diastolic, end-systolic and stroke volumes and ejection fraction. The change in diastolic volume in these patients was determined by the extent of coronary artery disease, propranolol therapy, end point of exercise and presence of collateral vessels. Furthermore, patients with previous myocardial infarction had a lower ejection fraction and higher end-diastolic and end-systolic volumes during exercise than those without myocardial infarction. In the 12 patients with chronic aortic regurgitation of moderate to severe degree, there was a decrease in the end-diastolic volume during exercise. This response was distinctly different from that of the normal subjects or the patients with coronary artery disease. All three groups had a significant decrease in pulmonary transit time during exercise. It is concluded that changes in cardiac output in normal subjects during upright exercise are related to augmentation of stroke volume and tachycardia, whereas in patients with coronary artery disease they are related mainly to tachycardia. Left ventricular dilatation during exercise occurred in some normal subjects and in patients with coronary artery disease but was not a consistent finding. However, a decrease in left ventricular end-diastolic volume is common in patients with aortic regurgitation. Such a decrease may be explained by a reduction in the regurgitant volume per beat caused by shortening of the diastolic filling period or a decrease in systemic vascular resistance, or both.

Adult↗
PubMed1981

Real-time inferior vena caval ultrasonography: normal and abnormal findings and its use in assessing right-heart function.

We studied the inferior vena cava (IVC) as an index of right-heart function in 111 patients. A two-dimensional echocardiographic sector was used to visualize the IVC, and its M-mode cursor was used to generate a time-motion record of the IVC size and pulsation. Normal subjects had a small presystolic A wave (less than 125% of the end-diastolic IVC dimension), a small systolic V wave (less than 140% of the end-diastolic IVC dimension), and a 50% inspiratory decrease in IVC dimension. The A wave was absent in patients with atrial fibrillation. When normalized for body surface area, mean end-diastolic IVC dimension correlated with mean right atrial pressure (r = 0.72, p less than 0.001). An A wave greater than or equal to 125% of end-diastolic IVC dimension was recorded in 71% of patients with sinus rhythm and an elevated right ventricular end-diastolic pressure of 10 mm Hg or greater, but in no patient with right ventricular end-diastolic pressure of less than 10 mm Hg (p less than 0.001). A V wave greater than or equal to 140% of end-diastolic IVC dimension was recorded in 75% of patients with severe tricuspid insufficiency, but in no patient with mild or no tricuspid insufficiency (p less than 0.001). The inspiratory decrease in IVC dimension correlated with radionuclide right ventricular ejection fraction (r = 0.75, p less than 0.001); no respiratory variation in end-diastolic IVC dimension occurred in patients with significant right ventricular dysfunction (right ventricular ejection less than 25%) or in patients with constrictive pericarditis.

Blood Pressure↗
PubMed1981

Exercise thallium 201 scintigraphy in evaluating aortocoronary bypass surgery.

Thirty patients with recurrent symptoms after aortocoronary bypass graft surgery underwent angiography as well as exercise thallium 201 imaging. Exercise imaging has been shown to be highly specific (100 percent in our study) in evaluating patients after bypass surgery. Patients with complete revascularization have normal thallium 201 images. Similarly, exercise-induced defects are seen only in the presence of incomplete revascularization. There are patients, however, with incomplete revascularization with normal exercise images, but these generally limited to the right coronary artery or the diagonal vessels or their grafts.

Adult↗