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Biomedical subjects

B Pitt

Publications and source records attributed to B Pitt.

At least 271 records · Page 15Linked to original sources

Predictors of clinical course, coronary anatomy and left ventricular function after recovery from acute myocardial infarction.

Patients who survive an acute myocardiac infarction (AMI) have significant coronary disease and are at risk for angina pectoris, recurrent myocardiac infarction and sudden death. This study provides data gathered prospectively for 106 patients surviving myocardial infarction who had coronary arteriography, left ventriculography and 24-hour electrocadiographic recordings before hospital discharge and were followed 30 months. Univariate analysis showed that low ejection fraction, proximal left anterior descending coronary disease and significant disease in all three coronary arteries were associated with a high risk of sudden cardial death. The ECG location or type of infarction was not helpful in predicting mortality, reinfarction or continuing angina. Multivariate analysis of 30 clinical and laboratory variables identified previous myocardial infarction and an ejection fraction less than 40% as the best predictors of mortality; all 13 patients who died were identified by these two variables. Three-vessel coronary artery disease, proximal left coronary disease and complicated late hospital-phase ventricular arrhythmias did not provide additional information about mortality once the information provided by the first two variables was considered. Multivariate analysis identified hypertension, three-vessel coronary disease, postinfarction angina pectoris and previous AMI as significant predictors of recurrent AMI during the 30 month follow-up.

Adult↗

Disopyramide-induced ventricular tachycardia.

A patient with ischemic cardiomyopathy and congestive heart failure was treated with disopyramide phosphate for ventricular arrhythmias. The development of ventricular tachycardia was associated with elevated plasma disopyramide levels and prolongation of the QRS and QT intervals, suggesting a disopyramide-induced depression of ventricular conduction and a prolongation of recovery. Thus, in patients with congestive heart failure, as well as in patients with renal and/or hepatic dysfunction, special care must be exercised with respect to the use of disopyramide.

Alcoholism↗

Segmental wall-motion analysis in the right anterior oblique projection: comparison of exercise equilibrium radionuclide ventriculography and exercise contrast ventriculography.

Thirty-nine patients with known or suspected coronary artery disease were studied at rest and during supine bicycle exercise with radionuclide and contrast left ventriculography. Analysis of regional wall motion was made by visual evaluation of the five standard 30 degrees right anterior oblique (RAO) wall segments in the contrast images and the corresponding 10 degrees RAO radionuclide segments. The radionuclide studies were evaluated independently by three observers using a five-point grading system. The interobserver wall-motion grading agreed completely in more than 80% of segments at rest and exercise, and agreed within one wall-motion grade in more than 95% of segments. The comparison of wall-motion grades between radionuclide and contrast ventriculograms showed complete agreement in 86% of segments at rest and in 78% during exercise, and agreement within one wall-motion grade in 97% of rest and 96% of exercise segments. Visual evaluation of 10 degrees RAO rest and exercise radionuclide ventriculograms compares favorably with rest and exercise 30 degrees RAO contrast ventriculograms and demonstrates satisfactory interobserver agreement.

Coronary Disease↗

Cardiac function in patients with prior myocarditis.

Gated cardiac blood-pool imaging under rest and exercise was used to assess left-ventricular functional reserve in six asymptomatic patients with prior myocarditis and six age matched control subjects. Coronary artery disease was excluded in three of the six patients by coronary arteriography. In the remaining three, coronary artery disease was thought unlikely on the basis of history and the presence, during exercise, of a normal ECG and normal Tl-201 myocardial image. Conventional indices of resting left-ventricular function--including cardiothoracic ratio, echocardiographic left-ventricular diameter, and percentage change in minor diameter--were normal in those with prior myocarditis. The mean resting left-ventricular ejection fraction was also normal by gated blood-pool imaging, and not significantly different from that for control patients: 0.58 +/- 0.05 and 0.65 +/- 0.02, respectively. Three patients with prior myocarditis had resting left-ventricular ejection fractions of less than 0.50. On exercise, the patients with prior myocarditis decreased their mean left-ventricular ejection fraction by an average of 8% compared with an increase of 15% in the control group (p less than 0.01). This study suggests that asymptomatic patients with prior myocarditis have left-ventricular dysfunction that may not be clinically apparent, and suggests the need for further long-term follow-up.

Adult↗

The importance of adequate exercise in the detection of coronary heart disease by radionuclide ventriculography.

Rest and exercise radionuclide ventriculograms were obtained on 77 symptomatic patients without prior documented coronary artery disease (CAD). Coronary artery disease was present by angiograms in 48. Radionuclide ventriculography (RNV) was abnormal in 41 patients (overall sensitivity 85%). In 29 patients with normal coronary arteries, RNV was normal in 24 (specificity 83%). To determine if the exercise level affects sensitivity, the studies were graded for adequacy of exercise. It was considered adequate if patients developed (a) chest pain, or (b) ST segment depression of at least 1 mm, or (c) if they achieved a pressure rate produce greater than 250. Among the 48 patients with coronary artery disease, 35 achieved adequate exercise. Thirty-three had an abnormal RNV (sensitivity 94%). In 13 patients who failed to achieve adequate exercise, RNV was abnormal in eight (sensitivity of only 62%). Some patients with coronary artery disease may have a normal ventricular response at inadequate levels of stress.

Angiography↗

Thallium-201 myocardial imaging in evaluation of asymptomatic individuals with ischaemic ST segment depression on exercise electrocardiogram.

Asymptomatic adults with normal physical examination, normal resting electrocardiogram, and normal routine laboratory evaluation who have a positive exercise electrocardiogram and abnormal exercise thallium-201 myocardial image have a very high probability of angiographically significant coronary artery disease. If, on the other hand, the exercise electrocardiogram is positive for "ischaemic" ST segment changes, but the exercise thallium image is normal, the probability for coronary disease is low. The exercise electrocardiogram combined with thallium-201 myocardial image are safe non-invasive methods which can be performed on an out-patient basis.

Adult↗

Exercise radionuclide ventriculography: practical considerations and sensitivity of coronary artery disease detection.

Eighty-nine patients were evaluated for coronary artery disease (CAD) with exercise radionuclide ventriculography (ERV) and contrast coronary angiography. In 70 patients with documented lesions the ERV was abnormal in 65 for a sensitivity of 93%. In patients with normal coronary arteries, the ERV was abnormal in none for a specificity of 100%. Sensitivity of ERV for detecting CAD was affected by the level of exercise achieved. In patients with documented CAD who achieved adequate exercise (i.e., pressure rate product (PRP) greater than 250 or the development of angina or ST segment depression during exercise), the sensitivity was 98% (56 of 57 patients). In those with documented CAD who failed to achieve adequate exercise, the sensitivity was 69% (9 of 13 patients).

Angiography↗

Exercise radionuclide ejection fraction: correlation with exercise contrast ventriculography.

Thirty-one patients with known or suspected coronary artery disease or aortic valvular disease were studied at rest and during supine bicycle exercise with radionuclide and contrast left ventriculography. The radionuclide ejection fractions calculated independently by three observers correlated well at rest (r = 0.96) and with exercise (r = 0.94). The calculated values also correlated well with those obtained for contrast ventriculography using the area-length method Dodge (r = 0.89 at rest and r = 0.90 with exercise). The results suggest that further clinical applications of exercise radionuclide ventriculography are justified.

Cardiac Output↗