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Biomedical subjects

P D Bourdillon

Publications and source records attributed to P D Bourdillon.

At least 19 recordsLinked to original sources
PubMed1997

Evaluation of patterns of perfusion and metabolism in dobutamine-responsive myocardium.

OBJECTIVES: We investigated the patterns of perfusion and metabolism in dysfunctional myocardium whose contractility improved with dobutamine. BACKGROUND: Clinical studies have suggested that dobutamine echocardiography can identify hibernating myocardium, but laboratory studies suggest that reduced perfusion limits the response to dobutamine. METHODS: Twenty-five patients with coronary disease and ventricular dysfunction underwent low (5 and 10 micrograms/kg body weight per min) and high dose (maximum of 50 micrograms/kg per min) dobutamine echocardiography and positron emission tomography (PET) using nitrogen-13 (N-13) ammonia and fluorine-18 fluorodeoxyglucose (FDG) for imaging of perfusion and metabolism. Wall motion and tracer uptake were scored in 16 left ventricular segments. RESULTS: Perfusion and metabolism were normal in 56.4%, mildly reduced in 29.1% and mismatched (reduced perfusion, preserved FDG uptake) in 14.5% of dysfunctional segments viable on PET. Wall motion improved with dobutamine in 89 dysfunctional segments (62 at low dose, 27 only at peak dose), and 86 of these (97%) were viable on PET. Improvement in wall motion with dobutamine was more common in segments with normal perfusion and metabolism (56.5%) than in those with mildly reduced tracer uptake (28.5%, p < 0.001) and those with mismatch (32%, p = 0.03). All the segments with a biphasic response were supplied by vessels with > or = 70% stenosis, and 88% had normal perfusion and metabolism. CONCLUSIONS: The majority of viable segments with rest dysfunction had normal perfusion and metabolism, suggesting that myocardial stunning was common. Improvement of wall motion at low and high doses of dobutamine was highly correlated with myocardial viability on PET and was more common in myocardium with normal perfusion. A biphasic response to dobutamine identified segments with normal perfusion and metabolism supplied by severely diseased vessels.

Ammonia↗
PubMed1996

Exercise echocardiography, angiography, and intracoronary ultrasound after cardiac transplantation.

Fifty-one consecutive patients underwent exercise echocardiography, angiography, and intracoronary ultrasound (ICUS) 2.5 years (range from 1 to 6) after cardiac transplantation. The average age of the donor was 29 years (range 13 to 50), and the average age of the recipient was 49 +/- 12 years. In total, 78 studies were performed, as 25 patients had >1 annual evaluation and 2 patients had 3 consecutive annual evaluations. Of the 78 angiographic studies, 40 (26 patients) had evidence of coronary artery disease, defined as a focal stenosis (>20%, n=4) or luminal irregularities (n=36). However, by ICUS all 51 patients had intimal thickening at some point, with 34 patients possessing diffuse disease and 17 focal intimal thickening only. Of the 25 serial studies, 12 progressed by at least 1 Stanford class. The sensitivity of angiography for determination of class III to IV intimal thickening was 64% and the specificity was 76%. On exercise echocardiography, 6 examinations revealed resting wall motions abnormalities, whereas 6 had inducible wall motion abnormalities with exercise. The sensitivity of exercise echocardiography to determine class III to IV intimal thickening was 15%, and the specificity was 85%. In conclusion, exercise echocardiography is an insensitive method for predicting transplant-mediated coronary artery disease, whereas luminal irregularities on angiography may predict the presence of Stanford grade III to IV intimal thickening.

Adult↗
PubMed1993

Intracoronary artery thrombus formation in unstable angina: a clinical, biochemical and angiographic correlation.

OBJECTIVES: We examined the relation between the level of urinary fibrinopeptide A and the presence of angiographic intracoronary thrombus in patients with unstable angina to determine whether this marker predicts active thrombus formation. BACKGROUND: Although it is known that thrombus plays a role in acute ischemic syndromes, a noninvasive method to predict its presence in individual patients with unstable angina has not been determined. Fibrinopeptide A is a polypeptide cleaved from fibrinogen by thrombin and thus is a sensitive marker of thrombin activity and fibrin generation. METHODS: Angiographic thrombus, graded 0 to 4, and the presence of ST segment depression or T wave inversions, or both, on the electrocardiogram (ECG) were related to fibrinopeptide A levels in 24 patients with rest angina of new onset, 18 with crescendo angina, 19 with stable angina and 9 with chest pain but without coronary artery disease. All patients had chest pain within the 24 h of sample acquisition. RESULTS: The angiographic incidence of thrombus was significantly higher in patients with new onset of rest angina (67%, p < 0.001) and crescendo angina (50%, p < 0.001) as were fibrinopeptide A levels (p = 0.002). Fibrinopeptide A levels correlated significantly (p < 0.001) with the presence of a filling defect (grade 4 intracoronary thrombus) or contrast staining (grade 3). All patients with fibrinopeptide A > or = 8 ng/mg creatinine showed grade 3 to 4 thrombus and 15 of 16 patients with levels > or = 6.0 ng/mg creatinine exhibited angiographic evidence of thrombus (13 with grades 3 to 4). Patients with reversible ST changes on the ECG had significantly higher levels of fibrinopeptide A (p < 0.001), and ST changes correlated significantly with the presence of angiographic thrombus (p < 0.001). Nonetheless, a significant minority of patients with unstable angina had neither angiographic nor biochemical evidence of thrombus. CONCLUSIONS: Elevated fibrinopeptide A levels in unstable angina reflected active intracoronary thrombus formation and were present in patients with angina of new onset as well as crescendo angina. Reversible ST changes are accompanied by thrombin activity and angiographic thrombus formation. However, a sizable percentage of patients with unstable angina had no evidence of thrombus and these patients may have had transient platelet aggregation without fibrin thrombus formation.

Angina, Unstable↗
PubMed1993

Double balloon mitral valvuloplasty through dual femoral vein punctures and a single atrial septal puncture.

A modification of a previously described double balloon mitral valvuloplasty procedure is described. This involves dual femoral vein punctures with a single atrial septal puncture. After initial transseptal catheterization and predilatation of the interatrial septum with an 8-mm balloon, a second catheter is advanced through the resulting atrial septal defect allowing access to the left atrium and left ventricle through the mitral valve via two separate femoral vein puncture sites. In comparison with the previously described technique using two balloon catheters inserted through a single femoral vein puncture site, this modification has reduced the amount of bleeding from the femoral vein and the need for transfusion. Furthermore, the potential for subsequent interatrial shunting is less than with the alternative previously described technique utilizing two femoral vein punctures with two separate punctures in the interatrial septum. In utilizing two separate femoral vein punctures with only one atrial septal puncture this technique combines advantages of the two previously described techniques.

Catheterization↗
PubMed1993

Low-dose dobutamine echocardiography detects reversible dysfunction after thrombolytic therapy of acute myocardial infarction.

BACKGROUND: Dysfunction after thrombolytic therapy of acute myocardial infarction (MI) may be reversible. Early after myocardial infarction, both reversible and irreversible injury may be manifested by regional wall motion abnormalities. Improved wall thickening during dobutamine infusion (dobutamine-responsive wall motion) may accurately identify reversibly injured segments. METHODS AND RESULTS: To determine whether dobutamine-responsive wall motion accurately detects reversible postischemic dysfunction irrespective of infarct location, multistage (baseline, 4 and 12 micrograms.kg-1.min-1, and peak) dobutamine echocardiography (DE) was performed within 7 days of thrombolytic therapy. Resting echocardiography was repeated > or = 4 weeks after MI, and reversible dysfunction was defined as improved wall motion. The accuracy of dobutamine-responsive wall motion was compared with that of signs of early reperfusion, non-Q-wave MI, and peak creatine kinase (CK). Sixty-three patients underwent DE without complications. Follow-up echocardiograms were done in 51 (81%) of these patients, and wall motion improved in 22 (41%). Dobutamine-responsive wall motion during all stages of DE was very specific for reversible dysfunction (90% to 93%) but sensitive (86%) only when hemodynamics were not altered (low dose, 4 micrograms.kg-1.min-1). Non-Q-wave MI and a low peak CK (< 1000 IU/mL) were also specific (89% to 93%) but less sensitive (64% [P = .16] and 55% [P < .05], respectively). Signs of early reperfusion did not identify postischemic dysfunction. Low-dose dobutamine-responsive wall motion and non-Q-wave MI independently identified reversible dysfunction, but only dobutamine-responsive wall motion was sensitive in all infarct locations. Non-Q-wave MI was sensitive only in anterior infarction. CONCLUSIONS: Multistage dobutamine echocardiography can be performed safely early after thrombolytic therapy. Low-dose dobutamine-responsive wall motion accurately detected reversible dysfunction in all infarct locations. Dobutamine-responsive wall motion and non-Q-wave infarction may be very useful for accurately identifying reversible dysfunction early after thrombolytic therapy for acute MI.

Adult↗
PubMed1992

Use of sideholes for diagnostic coronary arteriography by Judkins technique in patients with ostial coronary stenosis.

Patients with ostial left main coronary artery stenosis are at increased risk from diagnostic cardiac catheterization. In order to reduce this risk a modified Judkins coronary catheter with a sidehole 1.5-2 cm from the tip has been used in 6 patients in whom pressure damping was observed after initial use of a standard end-hole Judkins left coronary catheter. This eliminates damping and allows forceful hand injection with good proximal and distal vessel opacification. It also allows the acquisition of multiple views without the need for catheter removal after each injection, thereby reducing the risk involved in multiple cannulations of a vessel with a potentially unstable lesion at its origin. The technique has also been used for ostial lesions in a right coronary artery and a vein graft.

Cardiac Catheterization↗
PubMed1991

Restrictive hemodynamic patterns after cardiac transplantation: relationship to histologic signs of rejection.

Hemodynamic and echocardiographic data from 33 consecutive patients undergoing cardiac transplantation were correlated with endomyocardial biopsy results to determine whether reversible restrictive hemodynamics accompany histologic evidence of transplant rejection. During the study period 251 biopsy specimens were obtained during periods of no histologic evidence of transplant rejection and 52 episodes of mild, 20 episodes of moderate, and one episode of severe rejection. Right atrial mean pressure increased significantly during episodes of moderate transplant rejection (9.9 +/- 6.2 mm Hg, p less than 0.001) compared with pressures obtained during periods when there was no evidence of rejection (4.6 +/- 3.2 mm Hg), mild rejection (5.8 +/- 3.9 mm Hg), or resolving rejection (4.3 +/- 3.4 mm Hg). Y descent was elevated during moderate rejection (9.6 +/- 4.2 mm Hg, p less than 0.001) compared with pressures during episodes of no rejection (5.6 +/- 2.5 mm Hg), mild rejection (6.6 +/- 2.7 mm Hg), and resolving rejection (5.8 +/- 3.1 mm Hg) and showed a wave morphology consistent with a restrictive hemodynamic pattern. Pulmonary capillary wedge pressure was increased during moderate rejection (14.4 +/- 6.4 mm Hg) when compared with pressures obtained during episodes of no rejection (10.2 +/- 5.8 mm Hg) or resolving rejection (10.2 +/- 5.4 mm Hg) (p less than 0.02). Sensitivity for a right atrial mean pressure of 11 mm Hg indicating moderate rejection was 41% with a specificity of 96%. Sensitivity for Y descent (greater than or equal to 10 mm Hg) was 52% and specificity was 94%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Comparison of contrast angiography and two-dimensional echocardiography for the evaluation of left ventricular regional wall motion abnormalities after acute myocardial infarction.

Regional left ventricular wall motion abnormalities were assessed using 2-dimensional echocardiography and contrast ventriculography within 12 hours of the onset of chest pain in 20 patients with acute myocardial infarction (AMI); 10 patients had anterior infarctions and 10 had inferior. End-diastolic and end-systolic sinus beats from right anterior oblique contrast ventriculograms were analyzed using the center-line chord technique with both a standard overlap method of chord assignment and a nonoverlap method. Echocardiograms were obtained in parasternal long- and short-axis and apical 2- and 4-chamber views and analyzed using a 16-segment scoring system to derive anterior and infero-posterolateral wall motion indexes using both overlap (10 segments for anterior, 8 inferior) as well as nonoverlap (9 segments anterior, 7 inferior) methods of segment assignment. There was a significant inverse correlation between the standard (nonoverlap) echocardiographic analysis and the standard (overlap) angiographic analysis for infarct regions (y = -0.43 X +1.11, r = -0.59, p less than 0.05). Fifteen of 18 patients with angiographic infarct regional score less than or equal to -1 standard deviation/chord had an echocardiographic index greater than or equal to 1.5, while 15 of 16 patients with echocardiographic regional infarct index greater than or equal to 1.5 had an angiographic score less than or equal to -1 standard deviation/chord. Correlation between the 2 methods for noninfarct territories was poor (r = -0.34) because the angiographic method assesses hyperkinesis while the echocardiographic method does not.(ABSTRACT TRUNCATED AT 250 WORDS)

Contrast Media↗
PubMed1990

Improvement in rest and exercise-induced wall motion abnormalities after coronary angioplasty: an exercise echocardiographic study.

Exercise echocardiography was performed in 36 patients to evaluate functional improvement after coronary angioplasty. Thirty-one patients (86%) had provokable ischemia before angioplasty including 22 with an abnormal exercise electrocardiographic test (angina or ST depression), 25 with an abnormal exercise echocardiogram (exercise-induced wall motion abnormalities) and 16 with both tests abnormal. Nineteen patients had no induced ischemia after angioplasty. Seventeen (47%) continued to have ischemia that was limited in 12 to exercise-induced wall motion abnormalities, which were less severe compared with those of preangioplasty studies. Fifteen (65%) of 23 patients had improvement in rest wall motion abnormalities after angioplasty. The rest to immediate postexercise change in global wall motion score was significantly improved after angioplasty. The change in regional wall motion score was significantly improved after angioplasty in patients with single vessel right or left circumflex coronary artery disease and approached significant improvement (p = 0.06) in those with single vessel disease of the left anterior descending coronary artery. Exercise echocardiography improves the sensitivity of functional testing for ischemia, aids in localizing the ischemic zone and documents improvement in regional function after coronary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1990

Peripheral cardiopulmonary support during high-risk angioplasty.

We report the safety and feasibility of the first three patients using cardiopulmonary bypass support at the Indiana University Medical Center during PTCA. All patients had severe left ventricular dysfunction. Cannulation was performed using 18- or 20-French cannulae of the femoral vessels, either surgically or percutaneously. After heparinization with an activated clotting time of greater than 450 seconds, cardiopulmonary bypass was instituted using the Bard CPS system. Flows ranged from 3.0 to 4.3 L/min. Normasol was used to prime the pump. Blood was retransfused back into the patient at the end of the procedure. Bleeding was a problem in case 1 at the arterial cannulation site and subsequently was corrected for cases 2 and 3. Coronary angioplasties were deemed technically successful. We conclude that high-risk angioplasty can be performed in patients with poor left ventricular function using cardiopulmonary bypass support in the cardiac catheterization laboratory. Further study is indicated.

Aged↗
PubMed1989

Early recovery of regional left ventricular function after reperfusion in acute myocardial infarction assessed by serial two-dimensional echocardiography.

Although global and regional left ventricular (LV) function has been demonstrated to improve after reperfusion in acute myocardial infarction (AMI), the timing of these changes has not been well established. In this study, serial 2-dimensional echocardiography was used to assess regional LV function in 23 patients with AMI in whom reperfusion was accomplished by thrombolysis alone, by coronary angioplasty alone or by both interventions within 6 hours after onset of chest pain. Echocardiograms were performed before or within 6 hours after reperfusion (n = 23) and at 1 (n = 19), 3 (n = 21) and 7 (n = 20) days after reperfusion. Wall motion index and percentage of normally functioning muscle were calculated using a 16-segment scoring system analyzed in blinded fashion without knowledge of patient identity, therapy or time of study. The mean wall motion index improved from 1.78 +/- 0.48 to 1.56 +/- 0.38 at 1 day (n = 19, p less than 0.01), and to 1.48 +/- 0.37 at 3-7 days (p less than 0.01), with no significant difference between 3 days (1.49 +/- 0.39) and 7 days (1.42 +/- 0.30). There was a corresponding improvement in the percentage of normally functioning muscle, from 53 +/- 24% at 6 hours to 62 +/- 20% at 1 day (p less than 0.05) and to 67 +/- 18% at 3-7 days (p less than 0.01), again with no significant difference between 3 days (67 +/- 21) and 7 days (70 +/- 20).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Comparison of iced and room temperature injectate for thermodilution cardiac output.

Cardiac output estimation by thermodilution is carried out using room temperature or iced injectate, but the accuracy and variability of the two methods is not well documented. Room temperature and iced injectate were compared in 21 patients undergoing diagnostic cardiac catheterization. Dextrose injectate (10 ml) was administered in prefilled syringes left to stand either in iced water or in room air. Four injections were made sequentially with room temperature and iced injectate. Cardiac output by room temperature and iced injectate were not significantly different (4.70 +/- 1.22 for room temperature and 4.90 +/- 1.37 for iced injectate, n = 21, P = 0.155). There was a significant difference in the variance of the estimations by the two methods (room temperature = 0.296, iced = 0.120, P less than 0.005). From this variance the calculated number of measurements needed to estimate cardiac output to +/- 0.5 L/min with 95% confidence is seven for room temperature and four for iced injectate. For five patients with cardiac output less than 4.00 L/min with room temperature injectate, cardiac output with iced injectate was significantly higher (3.33 +/- 0.34 for room temperature vs. 3.69 +/- 0.49 for iced injectate, P = 0.05). Thus room temperature injectate generally gives a satisfactory cardiac output estimation but with significantly greater variability than iced injectate. Sample size for accurate cardiac output estimation must be greater with room temperature injectate. Iced injectate may over-estimate output when cardiac output is low.

Cardiac Catheterization↗