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Biomedical subjects

A Righetti

Publications and source records attributed to A Righetti.

83 records · Page 5Linked to original sources
PubMed1977

Detection of perioperative myocardial damage after coronary artery bypass graft surgery.

In order to evaluate methods for detecting peri-operative myocardial damage we studied 41 patients before and serially following coronary artery bypass graft surgery utilizing the 12-lead ECG, serum MB-CPK measurements, and 99mTc pyrophosphate myocardial scans. Six of the 41 patients (15%) developed persistent new Q waves after surgery. Six other patients demonstrated ischemic ST-T wave changes that persisted for 48 hours or more. Mean total MB-CPK released was highest for the group with new Q waves [1598+/-545 (SE) I.U./L-hr] as compared to the group with ischemic ST-T wave changes 708+/-65 I.U./L-hr) or the group with no ECG changes (262+/-47 I.U./L-hr). Ten patients (24%) has positive postoperative pyrophosphate scans consistent with myocardial infarction. The three techniques were compared in these 41 patients utilizing 465 I.U./L.-hr as the upper limit of normal MB-CPK released after uncomplicated coronary bypass surgery (no ECG changes, negative scan). Five patients with ischemic ECG changes had a positive scan and high MB-CPK; six patients with no ECG changes had high MB-CPK but a negative scan; and one patient with high MB-CPK and new Q wave had a negative scan. We conclude 1) new Q waves on ECG underestimate the incidence of myocardial damage after coronary artery surgery; 2) MB-CPK alone overestimates the incidence of infarction; and 3) a combination of the three techniques is the best means for detecting myocardial damage after coronary artery bypass graft surgery.

Adult↗
PubMed1977

Echocardiographic and roentgenographic determination of left ventricular size after coronary arterial bypass graft surgery.

In 38 patients undergoing elective coronary arterial bypass graft surgery, the radiographic dimension of the left side of the heart was determined and echocardiographic studies were performed before and after surgery. On the plain chest x-ray film one week after surgery, all patients showed an increase in the size of the left side of the heart, which usually was not accompanied by an increase in the echocardiographic left ventricular end-diastolic dimension; however, in 25 patients, pericardial fluid was detected soon after surgery, which would explain the enlarged cardiac silhouettes. Several months after surgery, the radiographic size of the heart returned to the preoperative value in most patients, and pericardial fluid was no longer demonstrated on the echocardiogram. Thus, pericardial fluid frequently is found in the first week following coronary arterial bypass graft surgery and may give the impression of increased cardiac size on plain chest x-ray films; however, echocardiographic studies provide a more accurate estimate of left ventricular size and reveal the presence of pericardial effusion.

Adult↗
PubMed1970

Induction of rat liver alkaline phosphatase: the mechanism of the serum elevation in bile duct obstruction.

Bile duct ligation in the rat leads to a rapid increase in hepatic and serum alkaline phosphatase activity. Within 12 hr after bile duct ligation, hepatic alkaline phosphatase has increased 7-fold and serum alkaline phosphatase activity 2(1/2)-fold. The elevation in the serum activity is completely due to an increase in an isozyme that appears to originate in the liver. This serum isozyme and liver phosphatase, both partially purified by DEAE-cellulose column chromatography, have identical Michaelis constants, pH optima, and rates of heat denaturation. These isozymes migrate identically when subjected to electrophoresis on polyacrylamide gel, and their migration rates are equally slowed after neuraminidase digestion. The data suggest that the rise in hepatic alkaline phosphatase activity is dependent on de novo protein synthesis. Cycloheximide, in a dose that inhibited incorporation of leucine-(14)C into protein by 68%, inhibited the rise in liver phosphatase by 98% and that in serum by 80%. The rise in liver phosphatase activity could not be accounted for by simple retention of alkaline phosphatase that would normally appear in bile. The rise in liver activity after bile duct ligation was 240 times greater than the amount of phosphatase that normally appears in bile over a similar period of time. Cycloheximide had no effect on the bile duct ligation-induced changes in the serum and liver glutamic pyruvic transaminase.

Alanine Transaminase↗
PubMedDate not supplied

Evaluation of left ventricular diastolic function at rest and during exercise by gated radionuclide angiocardiography in coronary artery disease patients.

The peak filling rate (PFR) is an index of the diastolic function and has been proposed as an excellent parameter for the evaluation and early detection of left ventricular (LV) dysfunction. This study contributes to the assessment of LV diastolic function at rest and during submaximal exercise in 19 normal subjects and in 42 patients with coronary artery disease (CAD). The PFR was compared to the ejection fraction (EF) and the peak ejection rate (PER)--both indexes of systolic LV function--after acquiring a high-resolution time-activity curve (time/frame between 10 and 30 msec) with gated radionuclide angiocardiography. In 23 patients with normal EF at rest (greater than or equal to 50%), PFR and PER were abnormally low in 87% and 43% of the cases respectively. During submaximal exercise in 13 CAD patients, EF, PFR and PER varied very little from baseline values but were significantly reduced compared to the values of normal subjects. The PFR proved to be a very sensitive indicator of LV dysfunction in coronary patients but was not capable of discriminating between one-, two- or three-vessel disease. Our results tend to show the PFR to be a good indicator of LV dysfunction at rest and during exercise and its usefulness for the assessment of LV function is becoming more and more evident in clinical practice.

Adult↗