PubMed Health⌕ Search

Biomedical subjects

B de Bruyne

Publications and source records attributed to B de Bruyne.

34 records · Page 2Linked to original sources
PubMed1996

Dobutamine-induced wall motion abnormalities: correlations with myocardial fractional flow reserve and quantitative coronary angiography.

OBJECTIVES: This study evaluated both the relation between dobutamine-induced wall motion abnormalities and the physiologic and morphologic features of epicardial coronary artery stenoses and the impact of the extent of the area at risk on the sensitivity of dobutamine echocardiography. BACKGROUND: The accuracy of dobutamine echocardiography has traditionally been assessed by comparing results with stenosis geometry. Myocardial fractional flow reserve is a functional index of coronary stenosis severity that takes into account both antero-grade and collateral flow and may therefore be a more appropriate standard for comparison. METHODS: Seventy-five patients with normal left ventricular function, good echocardiographic images and an isolated coronary stenosis underwent, within 6 h, dobutamine echocardiography, quantitative coronary angiography and intracoronary pressure measurements. Myocardial fractional flow reserve was calculated as the ratio of mean hyperemic distal coronary to aortic pressure. RESULTS: The degree of dobutamine-induced dyssynergy correlated significantly with percent diameter stenosis (r = 0.68), area stenosis (r = 0.68) and minimal lumen diameter (r = -0.60) and markedly better with myocardial fractional flow reserve (r = -0.77). However, marked dispersion of the individual data was observed. The sensitivity of dobutamine echocardiography in detecting lesions with a minimal lumen diameter < or = 1 mm and diameter stenosis > or = 50% was 83% and 80%, respectively. All but one patient with a myocardial fractional flow reserve >0.75 had a normal stress test result. Among patients with a myocardial fractional flow reserve < or = 0.75, the sensitivity of dobutamine echocardiography was significantly lower for lesions in vessels with a reference diameter < or = 2.6 mm than for lesions in larger vessels (58% vs. 90%, p = 0.008). CONCLUSIONS: 1) The magnitude of wall motion abnormalities induced by dobutamine infusion correlates with angiographic and, more closely, with functional indexes of stenosis severity, even though a wide scatter is observed. 2) In patients with a functionally significant stenosis, the amount of myocardium at risk is a critical determinant of the accuracy of dobutamine echocardiography.

Coronary Angiography↗
PubMed1996

Clinical and angiographic outcome of elective stent implantation in small coronary vessels: an analysis of the BENESTENT trial.

We examined the influence of vessel size using an intention-to-treat approach in 259 patients who underwent stent implantation and in 257 patients who underwent balloon angioplasty alone in the BENESTENT trial. In the stented population, smaller vessel size was associated with a higher stent:vessel ratio, a greater relative gain and a greater subsequent loss index, and a higher risk of adverse cardiac events. In the balloon angioplasty population small vessel size conveyed an increased requirement for revascularization but did not increase the risk of procedural failure or myocardial infarction during follow-up. Logistic regression indicated that decreasing vessel size (as a continous variable) was associated with an increasing risk of a cardiac event for both the stent and balloon angioplasty populations.

Angioplasty, Balloon, Coronary↗
PubMed1995

Dynamic left ventricular outflow tract obstruction after anterior myocardial infarction. A potential mechanism of myocardial rupture.

This study describes a dynamic left ventricular outflow tract gradient complicating an acute anterior myocardial infarction in two patients. In both cases, hyperdynamic contraction of the non-infarcted segments were noted in addition to large antero-apical a- or dyskinesia. Both patients had evidence of mitral annular calcifications, and the occurrence of dynamic outflow tract obstruction preceded sudden death. Early recognition of the underlying pathophysiological mechanism might have major therapeutic implications and could decrease the risk of myocardial rupture.

Aged↗
PubMed1995

Effect of aging on myocardial perfusion reserve.

UNLABELLED: Myocardial perfusion reserve (hyperemic divided by basal myocardial blood flow) describes vasodilator responsiveness of coronary-resistive vessels. The effect of aging and gender on myocardial perfusion reserve remains controversial. METHODS: We studied 56 normal volunteers (21 women, 35 men; aged 50 +/- 20 yr, range 21-86 yr) with 15O-water PET to measure myocardial blood flow during basal and hyperemic states with intravenous dipyridamole (0.56 mg/kg, n = 46) or adenosine (140 micrograms/kg/min, n = 10). For comparative analysis, patients were grouped according to age: < 30 yr (n = 11), 30-49 yr (n = 18), 50-69 yr (n = 15) and > or = 70 yr (n = 12). RESULTS: Overall, basal flow was 1.00 +/- 0.26 ml/min/g and hyperemic flow was 3.31 +/- 1.38 ml/min/g, resulting in a myocardial perfusion reserve of 3.38 +/- 1.35. There was an increase in basal flow with age (r = 0.45, p < 0.025), although hyperemic flow was only lower in patients > or = 70 yr, causing a significant reduction in myocardial perfusion reserve: 3.54 +/- 0.96 in < 30 yr, 4.23 +/- 1.35 in 30-49 yr, 3.51 +/- 1.21 in 50-69 yr and 1.94 +/- 0.46 in > or = 70 yr (p < 0.05 versus all groups < 70 yr). CONCLUSION: Myocardial blood flow during basal and hyperemia conditions are roughly comparable up to 60 yr of age. Above this age, there is significant increase in basal flow associated with an increase in systolic blood pressure. Above 70 yr, there is a significant reduction in hyperemic flow, and thus myocardial perfusion reserve independent of hemodynamic response to vasodilator stress.

Adenosine↗
PubMed1991

Cardiac tamponade early after thrombolysis for acute myocardial infarction: a rare but not reported hemorrhagic complication.

Among 392 consecutive patients admitted for acute myocardial infarction and treated with thrombolytic drugs, 4 patients (1%) developed an early hemorrhagic pericardial effusion (without ventricular wall rupture) evolving within 24 h to cardiogenic shock consequent to cardiac tamponade. They all suffered from a large anterior myocardial infarction treated within 4 h after onset of symptoms with intravenous anisoylated plasminogen streptokinase activator complex (one case), recombinant tissue-type plasminogen activator (rt-PA) (two cases) or streptokinase (one case), anticoagulation with heparin (all cases) and aspirin (three cases). As soon as pericardial effusion was established by echocardiography, emergency percutaneous pericardiocentesis was performed at the bedside 20 +/- 6 h after thrombolytic therapy was started. This corrected immediately the clinical and hemodynamic status of each patient and a catheter was left in the pericardial space for 34 +/- 18 h. Thus, in the presence of unexplained clinical and hemodynamic deterioration occurring during the first 24 h after thrombolytic treatment of a large myocardial infarction, cardiac tamponade should be suspected. Immediate percutaneous pericardiocentesis followed by continuous drainage is a simple and definitive treatment for this complication.

Aged↗
PubMed1991

Comparative effects of pacing-induced and balloon coronary occlusion ischemia on left ventricular diastolic function in man.

BACKGROUND: Effects of pacing-induced and coronary occlusion myocardial ischemia on left ventricular (LV) function have been compared only in anesthetized dogs. Diastolic properties of the same LV anterior wall segment were therefore compared in 12 patients with single-vessel proximal left anterior descending coronary artery stenosis at rest, immediately after 7 +/- 1.2 minutes of pacing, and at the end of a 1-minute balloon occlusion of coronary angioplasty (CO). METHODS AND RESULTS: Shifts of the diastolic LV pressure-length relation, derived from simultaneous tip-micromanometer LV pressure recordings and digital subtraction LV angiograms, were used as an index of regional diastolic LV distensibility of the anterior wall segment. Immediately after pacing, LV end-diastolic pressure rose from 13.5 +/- 3.5 to 23.8 +/- 7.0 mm Hg (p less than 0.01 versus at rest) without a significant change of the LV end-diastolic volume index (83.1 +/- 18.9 versus 88.4 +/- 16.5 ml/m2), percentage systolic shortening (%SS) of the ischemic segment fell from 40.1 +/- 10.6% to 25.2 +/- 8.6% (p less than 0.01), and the diastolic LV pressure-radial length (P-RL) plot of the ischemic segment was shifted upward by 7.1 +/- 5.0 mm Hg for portions of the plot that overlapped with the diastolic LV P-RL plot at rest. At the end of CO, LV end-diastolic pressure rose to 20.8 +/- 7.8 mm Hg (p less than 0.01 versus at rest) and the LV end-diastolic volume index rose to 95.6 +/- 16.3 ml/m2 (p less than 0.05 versus at rest, p less than 0.05 versus after pacing). Ejection fraction and %SS of the ischemic segment fell respectively from 76.6 +/- 6.8% to 46.6 +/- 11.4% (p less than 0.01 versus at rest, p less than 0.01 versus after pacing) and from 40.1 +/- 10.6% to 6.4 +/- 8.6% (p less than 0.01 versus at rest, p less than 0.01 versus after pacing). The diastolic LV P-RL plot of the ischemic segment was shifted upward by 3.1 +/- 2.3 mm Hg for portions of the plot that overlapped with the diastolic LV P-RL plot at rest. This upward shift at the end of CO was significantly smaller (p less than 0.05) than that immediately after pacing. At the end of CO, a correlation (p less than 0.03) was observed for the ischemic segment between %SS and upward shift of the diastolic LV P-RL plot. CONCLUSIONS: The upward shift of the diastolic LV P-RL plot, which was used as an index of decreased regional diastolic LV distensibility, was larger immediately after pacing than at the end of CO. Persistent systolic shortening of ischemic myocardium seems to be a prerequisite for a decrease in diastolic distensibility of the ischemic segment because of the higher %SS of the ischemic segment immediately after pacing, and because of the correlation at the end of CO between the upward shift of the diastolic LV P-RL plot and %SS of the ischemic segment.

Adult↗
PubMed1989

Doppler assessment of left ventricular diastolic filling during brief coronary occlusion.

To assess left ventricular diastolic filling in patients with single-vessel coronary artery disease, Doppler-derived transmitral velocity was studied in 22 normal subjects and in 15 patients with isolated proximal stenosis of the left anterior descending coronary artery (LAD) and normal systolic function of the left ventricle. Transmitral velocity was recorded before and after balloon inflation during coronary angioplasty. At baseline the transmitral velocity pattern in patients with LAD stenosis differed from that of normal subjects with a significant (p at least less than 0.05) decrease in the early diastolic filling phase (E area 0.094 +/- 0.022 m in normal subjects vs 0.078 +/- 0.008 m in patients) and an increase in the late diastolic filling phase (A area 0.034 +/- 0.007 m vs 0.042 +/- 0.008 m). Correspondingly the ratio E area/A area decreased (2.7 +/- 0.51 vs 1.9 +/- 0.4) and the ratio A area/total area increased (0.28 +/- 0.04 vs 0.35 +/- 0.05). During coronary occlusion the E area and the ratio E area/A area decreased further, whereas the A area and the ratio A area/total area increased. The results suggest that patients with single-vessel disease and normal systolic function often exhibit an altered pattern of transmitral velocity even in the absence of overt ischemia, and that during acute regional ischemia early diastolic filling is further compromised with compensatory enhancement of the late diastolic filling phase.

Adult↗
PubMed1988

Assessment of regional coronary flow reserve by digital angiography in patients with coronary artery disease.

Digital angiography provides a convenient means to quantify the progression of a contrast medium bolus injected into a coronary artery throughout the myocardium, which in turn yields information on myocardial perfusion. Sixteen patients presenting a single critical proximal stenosis (estimated diameter reduction greater than 80%) on either the left anterior descending coronary artery (LAD) or the left circumflex coronary artery (LCX) were studied. First, 12 consecutive end-diastolic images of an ECG-triggered intracoronary injection of 4 ml of iopamidol were acquired on 60 degree left anterior oblique projection under basal conditions. This was repeated 30 s after intracoronary injection of 12 mg of papaverine. For each image sequence, a densogram was computed in each pixel by fitting a curve through its 12 consecutive intensity values. The 'time of maximal pixel opacification' (TMAX) and the 'mean ascending time' (TMAT), expressed in cardiac cycles, were determined from each curve. Two myocardial regions of interest (ROI) were defined for each patient, one in the perfusion bed of the LAD, the other in the bed of the LCX. The mean values of TMAX and TMAT in each ROI were computed, at rest and during hyperemia. At rest, the mean values of TMAX and TMAT obtained from the ROI associated to the stenosis artery were not significantly different from the values obtained in the ROI associated with the intact artery. During hyperemia, a significant decrease of the mean TMAX and TMAT was observed in the normally perfused regions (p less than 0.001). The rest to hyperemia ratios of both TMAX and TMAT mean values were considered to be indices of coronary flow reserve.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Potential protective effect of high coronary wedge pressure on left ventricular function after coronary occlusion.

To assess the potential of coronary collateral circulation to protect myocardium after occlusion of a coronary vessel, the mean coronary wedge pressure, the angiographic grade of collateral channels, and the left ventricular function were studied in 47 consecutive patients with mechanical recanalization of totally occluded coronary arteries. Coronary wedge pressure measurements were obtained 39 +/- 51 days (range, 2 hours to 361 days) after the presumed time of occlusion. The patients were divided into two groups: 31 with a coronary wedge pressure more than 30 mm Hg (group 1) and 16 with a coronary wedge pressure of or less than 30 mm Hg (group 2). Patients in group 1 had a significantly higher mean global left ventricular ejection fraction than those in group 2 (63 +/- 9% vs. 49 +/- 7%, p less than 0.001). Regional left ventricular function (artery-related area change) was also superior in group 1 compared with group 2 (47 +/- 11% vs. 36 +/- 10%, p less than 0.01). Global left ventricular function was significantly correlated to coronary wedge pressure (r = 0.51, p less than 0.001) but not to the angiographic presence of collaterals. The data suggest that a high coronary wedge pressure is associated with improved left ventricular function after coronary artery occlusion and that coronary wedge pressure more accurately reflects the physiological role of collaterals than their angiographic presence.

Angiography↗
PubMed1987

[Percutaneous coronary angioplasty in unstable angina and acute infarction].

Unstable angina represents an indication for percutaneous transluminal coronary angioplasty (PTCA) provided it is based on a significant fixed lesion. A primary success rate of about 90% can be expected, but in 5% to 10% the intervention will cause a myocardial infarction. Mortality is higher than in patients with stable angina and does not differ from that of bypass surgery; however, it is still below 1%. At 1 year, 50% to 90% of the patients treated with initial success are asymptomatic if redilatations for recurrences (occurring in about one third) are included. - Acute myocardial infarction was introduced as an indication for PTCA in about 1980. PTCA was first used for failures, then for incomplete successes of intracoronary streptokinase therapy, and finally in patients without pretreatment. Currently, PTCA is being evaluated in multicenter studies as an adjunct to early intravenous fibrinolysis with clot specific agents (e.g., tissue-type plasminogen activator). PTCA achieves adequate initial reperfusion in about 80% irrespective of concomitant fibrinolytic therapy. It is complicated by occlusion of an already partially recanalized vessel in 4%. Late reocclusions occur in 15%, half of them accompanied by reinfarction. Intrahospital mortality is about 5% and increases by 1% up to 1 year. PTCA has its place in the treatment of unstable angina and acute infarction. In the latter it may be advantageous to precede it with early intravenous fibrinolysis.

Angina Pectoris↗
PubMed1987

[Change in indications for coronary angiography in a decade].

To characterize the changes in indications for coronary angiography we compared indications and therapeutic conclusions of cardiac catheterization, including coronary angiography, in 100 consecutive patients in 1975 and 100 consecutive patients in 1985. The baseline characteristics of the patients in the two groups were similar, except for age (50 +/- 10 vs 56 +/- 9 years, p less than 0.0001) and prior angioplasty (0 vs 12, p less than 0.0001). The main indications for coronary angiography in the two groups were (1975 vs 1985) chest pain in 67 vs 62 (n.s.), myocardial infarction in 10 vs 17 (n.s.), prior coronary surgery in 3 vs 0 (n.s.), major arrhythmias in 1 vs 1 (n.s.), and incidental (coronary pathology not the primary issue) in 19 vs 8 (p less than 0.05). We further analyzed each of the main indications in the two groups. Chest pain: angina ruled out in 21% vs 26% (n.s.), stable angina 64% vs 61% (n.s.), unstable angina 15% vs 13% (n.s.), positive non-invasive tests 39% vs 44% (n.s.). Myocardial infarction: acute intervention 0 vs 12% (n.s.), angina after infarction 20% vs 47% (n.s.), positive non-invasive tests after myocardial infarction 20% vs 41% (n.s.). Incidental: valvular heart disease 57% vs 63% (n.s.), cardiomyopathy 26% vs 13% (n.s.), congenital heart disease 11% vs 0 (n.s.), aortic dissection 5% vs 25% (n.s.), other 5% vs 0 (n.s.). Overall, clinical suspicion of coronary artery disease was confirmed and documented in 80% (65/81) vs 77% (61/79) of patients (n.s.), and normal coronary arteries were found in 20% (16/81) vs 23% (18/79) of patients respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Coronary wedge pressure: a predictor of restenosis after coronary balloon angioplasty.

Coronary wedge pressure is the pressure recorded distal to a stenosis while the inflated balloon occludes the coronary artery during angioplasty. This pressure has been shown to reflect actual (visible) and potential (recruitable) collateral flow to the stenosed artery, distal to the angioplasty site. In 100 consecutive vessels (91 patients) for which coronary wedge pressure had been measured at the time of angioplasty, the long-term (7 +/- 3 months) angiographic results was evaluated. The overall angiographic restenosis rate was 37%. It was 52% (25 of 48) in arteries with a coronary wedge pressure greater than or equal to 30 mm Hg and 23% (12 of 52) in arteries with a coronary wedge pressure less than 30 mm Hg (p less than 0.01). The mean coronary wedge pressure was 30 +/- 10 mm Hg for vessels with restenosis and 26 +/- 9 mm Hg for those without restenosis (p less than 0.01). The prevalence of angiographically visible collateral flow was 42% and 29%, respectively (p = NS). Neither age, sex, presence of unstable angina, left ventricular function, number of diseased vessels nor initial and final transstenotic pressure gradient and degree of stenosis were significantly associated with the long-term outcome after angioplasty. Restenosis rate is significantly increased when coronary wedge pressure measured at the time of angioplasty is high (greater than or equal to 30 mm Hg). This suggests a negative influence of competitive collateral flow on long-term results of angioplasty.

Angiography↗
PubMed1987

Quantification of valvular regurgitation by cardiac blood pool scintigraphy: correlation with catheterization.

UNLABELLED: The diagnosis of valvular regurgitation (R) is usually based on clinical signs. Quantification conventionally requires catheterization (C). We have quantified R with cardiac blood pool scintigraphy (CBPS) and compared the results with those obtained by C. Regurgitant fraction (RF) determined by C was calculated with the technique of Dodge. Forward output was measured by thermodilution or cardiogreen dilution. The RF at CBPS was obtained by the stroke index ratio (SIR) minus 1.2 divided by SIR, where SIR is the ratio of the stroke counts of left ventricle over those of the right ventricle. Stroke counts are calculated directly from the time-activity curves. Each time-activity curve was obtained by drawing one region of interest around each diastolic image. The correction factor (1.2) was calculated from a large normal population. 22 patients had aortic R, 7 mitral R, 12 both, 8 patients had no evidence of regurgitation. RF of the patients with R varied from 27 to 71% (x = 42%) at C and from 26 to 74% (y = 41%) at CBPS. Linear regression shows a good correlation coefficient (r = 0.82). The regression equation is y = 0.93x + 1.8. No correlation was found between RF (CBPS or C) and the severity of R assessed visually from angiography. IN CONCLUSION: CBPS, a non-invasive method, allows easy and repeatable determination of RF and correlates well with data obtained at catheterization.

Adult↗
PubMed1985

[Determination of pulmonary capillary wedge pressure by M-mode echocardiography].

Many workers have tried to define echocardiographic criteria of left ventricular function. The Q-MVC/AVC-E index (ratio of the interval between the start of the Q wave and mitral valve closure and the interval between aortic valve closure to the E point of maximal mitral opening) was proposed to quantify mean pulmonary capillary pressure. The valve of this index was assessed in 62 consecutive patients by 67 simultaneous measurements of mean pulmonary capillary pressure by catheterisation and M mode echocardiography. After the exclusion of pacemaker patients and those with arrhythmias (atrial fibrillation or flutter) or conduction defects, a close correlation was observed between the two methods. In 66% of patients in sinus rhythm without a conduction defect, the difference between the results obtained by the two methods was less than or equal to 2 mmHg. In 96% of cases, the difference was less than or equal to 5 mmHg (r = 0.97; n = 52, p less than 0.0001). In addition, the results of the echocardiographic measurements were reproducible in the same patient when the electrocardiographic parameters were the same. However, there is a large number of electrical and haemodynamic factors which can affect the two terms of this index, and a good quality echocardiographic recording in essential for the measurement of these intervals. Therefore, these theoretical and practical limitations oppose the substitution of echocardiography for right cardiac catheterisation for the determination of mean pulmonary capillary pressure.

Adult↗