Search PubMed⌕ Search

Biomedical subjects

H B Karunaratne

Publications and source records attributed to H B Karunaratne.

10 recordsLinked to original sources
PubMed1994

The role of imaging techniques in stress testing.

The addition of various cardiac imaging techniques to standard ECG stress testing has permitted enhanced diagnostic capability in the evaluation of patients with suspected coronary artery disease. In addition, the prognostic and pathophysiologic information provided by such imaging modalities has given us insight not previously available by standard stress testing alone. This has been helpful in guiding management decisions in patients with known coronary artery disease. The modalities include myocardial perfusion imaging, stress echocardiography, and radionuclide ventriculography. These techniques can provide complementing and unique information in the evaluation of myocardial blood flow, function, and viability.

Echocardiography↗
PubMed1992

Exercise stress testing for the family physician: Part I. Performing the test.

Equipment required for exercise stress testing includes a monitor, a recorder and a treadmill or ergometer, and costs from about $13,000 to $18,000. Primary candidates for the procedure include asymptomatic patients at high risk for coronary artery disease and patients with atypical chest pain. Careful pretest patient selection will usually prevent complications such as precipitation of an acute myocardial infarction. The physician performing the test is responsible for selecting the appropriate exercise protocol, monitoring the patient during the test and determining when to terminate the test.

Clinical Protocols↗
PubMed1992

Exercise stress testing for the family physician: Part II. Interpretation of the results.

Information gained from exercise stress testing includes the heart rate and blood pressure response, the presence of symptoms or dysrhythmias, functional aerobic capacity and evidence of myocardial ischemia. Certain ST-segment patterns correlate with various degrees of ischemia. Overall, stress testing has a sensitivity and a specificity of about 70 and 75 percent, respectively, but the results are even more useful than this when considered in light of the pre- and post-test probability of coronary artery disease. Use of the exercise test score and decision-tree algorithms is helpful in clinical decision making.

Algorithms↗
PubMed1979

Calcific stenosis of the porcine heterograft.

We have encountered two cases of late calcification of the porcine heterograft. A patient in chronic renal failure died of sepsis and endocarditis fifteen months after replacement of the mitral and tricuspid valves. At postmortem examination, both heterograft valves exhibited severe calcification and thrombosis. A second patient with rheumatic heart disease and sickle cell disease underwent mitral valve replacement for severe regurgitation. Thirty months later, cardiac catheterization revealed prosthetic valve stenosis. The valve was replaced successfully, and the excised heterograft exhibited severe calcification with restriction of leaflet motion. Although calcification of the porcine heterograft is known to occur in patients with infection or disorders of calcium metabolism, dysfunction of the heterograft is rare in our experience.

Adolescent↗
PubMed1979

Detection, prediction, and significance of perioperative myocardial infarction following aorta-coronary bypass.

One hundred consecutive patients undergoing aorta-coronary bypass grafting (ACBG) alone, without ventricular venting, were prospectively studied to determine the incidence and consequence of perioperative myocardial infarction (PMI) and the clinical variables that were predictive of PMI. Incidence was determined by serial electrocardiography (ECG) 100 patients; serum CK, GOT, and LDH (100 patients). CK isoenzymes (qualitative 100 patients, quantitated 50 patients); vectorcardiography (VCG) (78 patients); and 99mtechnetium pyrophosphate scintigraphy (TcPyp) (52 patients). The incidence of PMI by ECG was 9%; an additional 8% of cases was diagnosed by enzymes alone. The incidence of diagnostic change by VCG was 19% and by scintigraphy, 25%. Using at least one changed variable of the remaining three as the reference standard, the relative sensitivity and relative specificity of given variables in the diagnosis of PMI were as follows: ECG 67% and 100%, respectively; VCG 85% and 94%; scintigraphy 92% and 97%; and serum enzymes 86% and 96%. By univariate analysis, unstable angina was the only significant predictor of PMI. The operative mortality rate was 2% and the mortality rate at 12 months was 5%. There was a significantly greater mortality rate in patients with PMI diagnosed by ECG (p less than 0.01), in patients with unstable angina pectoris before operation (p less than 0.05), and in women (p less than 0.05).

Analysis of Variance↗
PubMed1977

Hypertrophic cardiomyopathy with midventricular obstruction associated with mitral stenosis: partial relief of the obstruction by papillary muscle and trabecular resection.

A patient is reported with hypertrophic cardiomyopathy where midventricular obstruction was found in association with mitral stenosis. Partial relief of the intraventricular obstruction was obtained by extensive papillary and trabecular muscle resection in the mid-left ventricular area, in conjunction with mitral valve replacement with a porcine heterograft.

Adult↗
PubMed1977

Assessment of diagnostic value of technetium-99m pyrophosphate myocardial scintigraphy in 80 patients with possible acute myocardial infarction.

The diagnostic value of technetium-99m-pyrophosphate (Tc-pyrophosphate) myocardial scintigraphy was determined in 80 consecutive patients who had been admitted to the coronary care unit in order to rule out an acute myocardial infarction. Scintigraphic findings obtained within 5 days of admission were correlated with the final cardiac diagnosis determined for each patient. Significant myocardial uptake of Tc-pyrophosphate (positive scans) occurred in 13 of 22 patients (59%) who had enzyme and/or electrocardiographic proven acute myocardial infarct: 3 out of 5 with transmural myocardial infarct, 9 of 16 with nontransmural myocardial infarct, and 1 patient with left bundle-branch block. Of 58 patients who showed no evidence of acute myocardial infarction, positive scans occurred in 14 of 33 patients who had unstable angina pectoris (42%), 0 of 6 who had congestive heart failure, 6 of 9 who had other acute cardiac syndromes, and in 0 of 10 who had noncardiac chest pain. In the patients with unstable angina pectoris positive scans could not be predicted on the basis of the history, electrocardiographic findings or the arteriographically determined severity of the coronary artery disease. Blood levels of Tc-99m activity measured in 21 cardiac patients and in 6 volunteers did not correlate with the uptake intensity of Tc-pyrophosphate. These findings suggest caution in the use of this imaging method for the diagnosis of acute myocardial infarct in patients admitted with 'rule out myocardial infarction'.

Acute Disease↗