Search PubMed⌕ Search

Biomedical subjects

D T Kelly

Publications and source records attributed to D T Kelly.

At least 109 records · Page 6Linked to original sources

Coronary spasm management with verapamil (Isoptin).

Because of recurrent chest pain, 17 patients with documented spasm in coronary arteries without severe atherosclerotic obstructions were treated with verapamil in an open trial, using doses of 120 mg/day to 480 mg/day (mean, 240 mg/day). Thirteen patients received additional oral isosorbide dinitrate (30 mg/day). Eleven patients became asymptomatic, and four experienced marked reduction in frequency of attacks (one to four a month). While two patients did not respond, in most patients verapamil was effective in preventing attacks of angina due to coronary spasm.

Administration, Oral↗

Uremic cardiomyopathy--effect of hemodialysis on left ventricular function in end-stage renal failure.

Left ventricular ejection fraction was measured by radionuclide left ventriculography before and immediately after hemodialysis in 20 uremic patients, 11 of whom presented with congestive heart failure. Ejection fraction and contraction were normal in 15 patients (Group A), six of whom had signs of congestive failure; they were abnormal in five patients (Group B), all of whom were in clinical heart failure. Mean arterial pressure and body weight decreased by a similar amount after dialysis in both groups, and heart rate did not change. In Group A ejection fraction was unchanged by dialysis (0.63 +/- before vs. 0.62 +/- 0.09 after) (mean +/- S.D.), but in Group B it was improved significantly (0.32 +/- 0.04 before vs. 0.44 0.08 after) (P less than 0.01). In three patients in Group B cardiomegaly and ejection fraction returned to normal with long-term hemodialysis. In end-state renal failure, radionuclide left ventriculography can separate patients with circulatory congestion due to fluid overload from patients with left ventricular dysfunction in whom hemodialysis can provide immediate and long-term improvement.

Adolescent↗

Coronary artery spasm: use of ergonovine in diagnosis.

Ergonovine maleate was administered to 69 patients with chest pain but without significant coronary artery disease (less than 10% luminal diameter obstruction) to determine whether coronary artery spasm could be provoked. Coronary artery spasm was seen at angiography, or inferred from ECG or thallium myocardial perfusion scan changes. The test was positive in 16 patients: all five patients with documented variant angina (Group A); ten of the 19 patients with suspected variant angina (Group B); one of the 11 patients with exercise-induced chest pain (Group C); and none of the 34 patients with atypical chest pain (Group D). Patients with a positive test usually smoked, complained of recurrent nocturnal or early morning chest pain, showed ST changes during spontaneous chest pain and had minot degrees of fixed coronary obstruction (30--70%), when compared to those with a negative test. The only major side effect of the test was transient ventricular tachycardia which occurred in three patients and was reverted by sublingual and parenteral nitroglycerine.

Aged↗

Serial thallium-201 myocardial perfusion scanning in acute myocardial infarction.

Serial myocardial perfusion scanning was performed in 30 patients with acute myocardial infarction. Scanning was commenced less than six hours after onset of symptoms in 12 patients, 6-24 hr in eight and 24-120 hr in ten. All 30 patients showed thallium defects corresponding to the ECG site of infarction. When initial and four-hour scans were compared, constant defects were present in ten patients and changing defects in 20. Of the 169 segments with defects on the initial scan, 117 (69%) remained constant, 41 (24%) improved, and 11 (7%) deteriorated. More defects changed in the patients scanned earlier (less than 6 hr) than in the patients scanned later (more than 6 hr) (42% vs 23% P less than 0.025), and more defects changed in patients with subendocardial compared to transmural infarction (49% vs 26% P less than 0.025). During a mean follow-up period of 18 months, seven patients died, two developed left ventricular failure, seven had angina and 14 remained asymptomatic. The non-survivors had significantly larger thallium defects than the survivors (55 +/- 15% vs 37 +/- 14%, P less than 0.005). Serial change on thallium scanning was not related to the clinical course. Perfusion defects on serial thallium scanning are useful in detecting and localising early myocardial infarction and the size of defects is related to the subsequent clinical course. Changing perfusion defects on serial scanning suggesting peri-infarctional ischaemia are common, and make assessment of therapeutic interventions to limit infarct size difficult, but are not related to the clinical course.

Adult↗

The value of exercise electrocardiography and exercise thallium-201 myocardial perfusion scanning in determining the presence of single vessel coronary artery obstruction.

In 39 patients with single vessel coronary artery disease and no previous myocardial infarction, exercise thallium-201 myocardial perfusion scanning and 12 lead exercise electrocardiography (ECG) were compared to see how reliably each method identified the site of coronary artery obstruction. Significant (greater than or equal to 70% diameter) stenosis was present in the left anterior descending (LAD) coronary artery in 21 patients, in the right coronary artery (RCA) in 14 patients and in the left circumflex (LCX) in four patients. Thallium defects on the scan in the septal (SEPT), anteroseptal (ANT SEPT) and anterior (ANT) segments correlated (P less than 0 . 0005) with LAD disease and defects in the inferior (INF), posteroinferior (POST INF), and posterior (POST) segments correlated (P less than 0 . 0005) with RCA or LCX disease. Exercise induced ST segment elevation in VI and/or AVL correlated with LAD disease. The site of ischaemic ST depression did not correlate with disease in any vessel. ST segment depression in leads L2, 3, AVF (67%) and in leads V4--6 (67%) was most sensitive for detecting patients with LAD disease and ST depression in leads V4--6 was most sensitive (56%) for detecting patients with RCA or LCX disease but neither differentiated LAD from RCA/LCX disease.

Adult↗

Noninvasive prediction of multivessel disease after myocardial infarction.

In 65 patients with a previous transmural myocardial infarction (anterior in 33, inferior in 32), exercise thallium scanning was compared with 12-lead exercise electrocardiography to see if multivessel disease could be detected. At coronary arteriography 40 patients were shown to have multivessel disease ( greater than or equal to 70% diameter stenosis in two or three vessels) and 25 patients had one-vessel disease. On the exercise scan thallium defects corresponding to the electrocardiographic site of infarction were present in all patients. Patients wih one-vessel and multivessel disease were separated by exercise-induced angina, perfusion defects on the exercise thallium scan in more than one specific vasculare area, and a positive exercise ECG associated with angina, but not by a positive exercise ECG alone. Of the 40 patients with multivessel disease, 85% had defects in more than one vascular area on the thallium scan and 70% had a positive exercise ECG (p = NS). Of the 37 patients with thallium defects in more than one specific vascular area, 92% had multivessel disease, compared with 72% of the 39 patients who had a positive exercise ECG (p < 0.05). periinfactional ischemia was present in 38 of the 65 patients (58%) ( 14 of 25 with one-vessel disease and 24 of 40 with multivessel disease), and did not correlate with the severity of the corresponding coronary artery disease. When thallium defects that resolved were noted in a second vascular area, they were associated with a resolving rather than a constant defect in the vascular area where the infarction had occurred ( p < 0.005). In patients after a transmural myocardial infarction, multivessel disease can be better differentiated from one-vessel disease by thallium scanning than by exercise electrocardiography.

Adult↗

Effect of dietary salt, arsenic and copper additions and waste management systems on selected microbial organisms in swine wastes.

Selected microbial organisms were counted in swine wastes during three studies in which the primary objective was to investigate the effects of feed additives and waste management systems on swine waste composition. Dietary salt (NaCl) levels (.2, .5%), dietary arsanilic acid levels (0, 100, 200 ppm), supplemental copper levels (0, 125, 250 ppm) and waste management systems (oxidation ditch, anaerobic deep pit, anaerobic lagoon) were compared in this series of studies. Dietary salt level did not affect total coliform and fecal streptococci concentrations in swine waste. Supplemental copper and arsanilic acid increased total coliform counts (dry matter basis) in anaerobic pit wastes over counts observed with the control. Salmonella spp concentrations were increased in the anaerobic pit waste at the end of the 104-day feeding trial, especially with the 250-ppm copper diet. Staphylococci spp organisms were not affected by supplemental copper. In all studies, concentrations of the microorganisms cultured were higher in freshly excreted waste than in waste stored and partially treated in the waste systems studies. Temperature, diultion and waste handling systems had some effects on microbial populations.

Animals↗

Exercise thallium imaging: location of perfusion abnormalities in single-vessel coronary disease.

Exercise-induced thallium defects were segmentally analyzed in four standard views (anterior, 40 degrees left anterior oblique, 60 degrees left anterior oblique, and left lateral) and correlated with the arteriographic findings in 49 patients with single-vessel disease (> 70% diameter narrowing). Defects in the septal (SEPT), anteroiseptal (ANT SEPT), and anterior (ANT) segments correlated (p < 0. 0005) with stenosis of the left anterior descending coronary artery (LAD). For LAD disease the ANT SEPT segment had the highest sensitivity (84%) and specificity (100%). Defects in the inferior (INF), posteroinferior (POST INF), and posterior (POST) segments correlated (p < 0.0005) with either right (RCA) or circumflex (LCX) stenosis. For RCA or LCX disease, the POST segment had the highest sensitivity (82%) and specificity (100%). The site of single-vessel coronary artery disease can be accurately predicted noninvasively by segmental analysis of thallium images in four anatomical projections.

Adult↗

Serial exercise thallium myocardial perfusion scanning and exercise electrocardiography in the diagnosis of coronary artery disease.

Serial exercise thallium-201 myocardial perfusion scanning (exercise and 4-hour redistribution) was compared to rest and exercise electrocardiography (ECG) for the detection of coronary artery disease in 125 patients with known or suspected coronary artery disease. All patients underwent coronary arteriography and 108 were found to have significant coronary artery lesions. The serial exercise thallium scan was significantly more sensitive than rest and exercise ECG in detecting coronary artery disease (94% v. 83% P less than 0.01). The sensitivity of a reversible thallium perfusion scan abnormality and a positive exercise ECG for detecting exercise induced myocardial ischaemia in coronary artery disease was similar (69% v. 63%). The exercise thallium scan complemented the exercise ECG, and the sensitivity of the combined test was significantly greater than the exercise ECG alone (84% v. 63% P less than 0.001). The specificity for coronary artery disease of the exercise ECG was 65% and that of the exercise thallium-201 myocardial perfusion scan was 82% (P = NS). Thallium-201 myocardial perfusion scanning complements the rest and exercise ECG in the non-invasive detection of coronary artery disease.

Adult↗

Multivessel coronary artery spasm.

A 60-year-old patient with variant angina was shown to have myocardial ischemia in two different regions supplied by separate major coronary arteries. Neither artery had significant coronary atherosclerotic obstruction. Ventricular fibrillation was noted during ST-segment elevation in anteroseptal leads. The attacks of pain and arrhythmias disappeared during nifedipine therapy.

Angina Pectoris↗

Preoperative and postoperative technetium-99m pyrophosphate myocardial scintigraphy in the assessment of operative infarction in coronary artery surgery.

The incidence of operative myocardial infarction was assessed by electrocardiogram (ECG) and technetium-99m pyrophosphate (99mTc-PyP) myocardial scintigrams in 89 consecutive patients undergoing coronary artery bypass grafting (CABG). Myocardial scintigrams were performed on the day before operation and repeated 2 to 3 days postoperatively. All patients survived operation, with three in-hospital deaths not related to myocardial infarction (mortality rate 3 percent). Operative infarction was assessed to have occurred in four of 89 patients (4 percent). Two had new Q waves and positive scintigrams; one, major ST-T wave changes and a positive scintigram; and the fourth, new Q waves without a positive scintigram. Three further patients (3 percent) had Q waves and positive scintigrams postoperatively, but myocardial infarction was evolving before anesthesia and operation. Twenty-seven of 89 patients (30 percent) were found to have abnormal scintigrams preoperatively. In two patients, both operated upon with evolving myocardial infarction, the scintigram was worse postoperatively. In 13 patients the scintigram was improved after operation. In 12 patients (13 percent) the abnormal preoperative scintigram was unchanged after operation. Preoperative and postoperative myocardial scintigrams and ECG's must be compared to assess the incidence of operative myocardial infarction in patients undergoing CABG.

Adult↗

Myocardial perfusion scanning with thallium--201 for the non-invasive diagnosis of coronary artery disease.

Thallium--201 myocardial perfusion scanning has been evaluated in Australia in patients with coronary artery disease. Myocardial scans reliably detect both acute myocardial infarction and the transient myocardial ischaemia of angina pectoris. The non-invasive nature, ease of study, and the ability to scan patients with conventional cameras makes thallium--201 an attractive additional diagnostic agent for patients with suspected coronary artery disease. Although thallium--201 reliably indicates perfusion defects in the myocardium, its diagnostic use at the moment should be reserved to clarify such diagnostic problems in patients with coronary artery disease which cannot be satisfactorily explained by conventional investigation.

Angina Pectoris↗

Radionuclide imaging to assess myocardial damage during open heart surgery.

Technetium 99m Pyrophosphate imaging before and after open heart surgery was performed in 38 patients to estimate the incidence of peri-operative infarction. Positive images were present pre-operatively in 11 of 30 patients with coronary artery disease. In three patients the images changed from negative to positive and in two this was thought to be due to infarction produced at operation. The high incidence of positive pre-operative images emphasises that many patients with evolving myocardial infarction, unstable angina or severe heart failure are now operated upon without delay. Because many patients have positive images before surgery pre-operative and post-operative images must be compared to assess myocardial damage due to surgery.

Adult↗

"Hot spot" myocardial scanning: experiences with a mobile nuclear camera in a coronary care unit.

Twenty-nine patients with suspected or actual myocardial infarction have had myocardial "hot spot" scans with technietium 99m pyrophosphate, using a mobile nuclear camera in a coronary care unit. Nine patients with transmural infarcts had positive scans. Nine out of 12 patients thought to have had endocardial infarction had positive scans. Two patients who had had intramuscular injections presented with chest pain and abnormally high serum enzyme levels, but had negative scans. Myocardial radionuclide scanning with a mobile nuclear camera is a rapid, easy, repeatable, non-invasive method of helping to confirm or exclude the diagnosis of myocardial infarction and, used together with other available tests, is a valuable additional diagnostic aid.

Adult↗