Biomedical subjects

M D Winniford

Publications and source records attributed to M D Winniford.

At least 19 recordsLinked to original sources

PubMed1996

Perforation of saphenous vein graft during coronary stenting: a case report.

We report on a case of coronary perforation during stenting of a saphenous vein graft with a biliary stent. Sealing of the perforation was achieved with another biliary stent deployed within the first stent at the site of the perforation, and with prolonged balloon inflation. This case illustrates that vein graft perforation can occur with coronary stenting, and could potentially be treated with prolonged balloon inflation and/or stenting at the site of the first stent.

Coronary Angiography↗

PubMed1996

Does pharmacologic coronary flow reserve reflect vasodilator responsiveness to increased myocardial demand in humans?

OBJECTIVE: To assess the relationship between maximal pharmacologic coronary flow reserve and metabolic coronary vasodilation in nonstenotic coronary arteries. BACKGROUND: Evaluation of the coronary microcirculation in humans during cardiac catheterization is commonly performed by assessment of coronary hemodynamics during administration of potent coronary vasodilators. However, the relationship between maximal pharmacologic vasodilation and flow increases occurring in response to increased myocardial demand has not been evaluated. METHODS: The coronary blood flow responses to a maximally dilating dose of intracoronary adenosine or papaverine and to a standardized atrial pacing stress were assessed in 49 patients using intracoronary Doppler velocimetry. The blood flow responses to a maximally dilating dose of intracoronary adenosine and to intravenous infusion of dobutamine were determined in 13 patients. RESULTS: The maximal pharmacologic coronary flow reserve averaged 3.2 +/- 0.1 (mean +/- SEM). The coronary blood flow velocity increased by 32 +/- 3% during atrial pacing, and the change in coronary flow velocity was correlated with the change in the mean arterial pressure x heart rate product during pacing. Regression analysis revealed no relationship between the pharmacologic coronary flow reserve and the change in coronary flow velocity during atrial pacing or the response of the flow to pacing normalized with respect to the magnitude of stress reflected by the change in rate x pressure product. The coronary blood flow velocity increased by 135 +/- 16% during dobutamine infusion. Regression analysis revealed no relationship between the pharmacologic coronary flow reserve and the change in coronary flow velocity during dobutamine infusion. CONCLUSIONS: Knowledge of the maximal pharmacologic coronary flow reserve is an inadequate surrogate for assessment of coronary vasodilation in response to increases in myocardial metabolic demand in nonstenotic arteries.

Adenosine↗

PubMed1996

The effect of aminophylline on pharmacological stress with intravenous adenosine.

Myocardial perfusion imaging with adenosine pharmacological stress may be useful in patients with obstructive lung disease who are unable to exercise. However, these patients are often treated with medications containing theophylline, which is an adenosine antagonist. This study assessed the effect of aminophylline on coronary vasodilation produced by intravenous adenosine as commonly used during cardiac imaging. Changes in coronary flow velocity (measured by intracoronary Doppler catheter) heart rate, arterial pressure and changes in coronary resistance were measured during intravenous infusion of adenosine at 140 micrograms/kg/min before and after aminophylline, 6 mg/kg intravenously in 12 patients. After aminophylline infusion, the theophylline level averaged 14 +/- 1 microgram/mL. The coronary hemodynamic effects of adenosine were markedly attenuated by aminophylline. Adenosine increased coronary blood flow velocity by 192 +/- 39% at control and 78 +/- 16% after aminophylline (P < .05 v control). Adenosine produced a 63 +/- 5% decrease in coronary vascular resistance at control and 40 +/- 6% (P < .05) after aminophylline. The utility of myocardial imaging techniques using coronary vasodilation with intravenous adenosine may be reduced in patients treated with theophylline-containing preparations.

Adenosine↗

PubMed1995

Maximal coronary flow reserve and metabolic coronary vasodilation in patients with diabetes mellitus.

BACKGROUND: Structural and functional abnormalities of the coronary microcirculation have been reported in experimental diabetes mellitus. The purpose of this study was to evaluate coronary microvascular function in human diabetes. METHODS AND RESULTS: Twenty-four diabetic and 31 nondiabetic patients were studied during cardiac catheterization. A Doppler catheter or guidewire was used to measure changes in coronary blood flow velocity in a nonstenotic artery. Maximal coronary blood flow reserve was determined by using intracoronary adenosine or papaverine. Coronary dilation in response to an increase in myocardial metabolic demand was assessed by using rapid atrial pacing. Maximal vasodilator responses to papaverine and adenosine were compared in 12 diabetic patients. Maximal pharmacologic coronary flow reserve was depressed in diabetic (2.8 +/- 0.2, n = 19) compared with nondiabetic (3.7 +/- 0.2, n = 21, P < .001) patients. During atrial pacing, the decrease in coronary vascular resistance was attenuated in the diabetic (-14 +/- 3%) compared with the nondiabetic (-24 +/- 2%, P < .05) patients. Differences in coronary microvascular function between diabetic and nondiabetic patients were not attributable to differences in drug therapy, resting hemodynamics, or incidence of hypertension. In 12 diabetic patients the maximal coronary vasodilator responses to papaverine and adenosine were similar. CONCLUSIONS: This study demonstrates both reduced maximal coronary vasodilation and impairment in the regulation of coronary flow in response to submaximal increases in myocardial demand in patients with diabetes mellitus. These microvascular abnormalities may lead to myocardial ischemia in the absence of epicardial coronary atherosclerosis in some circumstances, and thus contribute to adverse cardiovascular events in diabetic patients.

Adenosine↗

PubMed1995

Electron-beam computed tomographic detection of coronary calcification in patients undergoing percutaneous transluminal coronary angioplasty: predictability of restenosis. A preliminary report.

Coronary artery calcification is a recognized marker for coronary atherosclerosis; however, the relationship between calcification and the success of balloon angioplasty at a calcification site has not been determined. The purpose of this study was to evaluate whether the presence of coronary artery calcification, as detected by electron bean computed tomography (EBCT), was predictive of restenosis after percutaneous transluminal coronary angioplasty (PTCA). Site- specific coronary calcification was determined by EBCT in 20 patients with 24 lesions before, immediately after, and 2 to 18 month after PTCA. Calcification was scored using >130 Hounsfield units and >1.02-mm2 area criteria. Coronary calcium at the PTCA site was significantly greater in restenosed versus nonrestenosed patients (109.16 +/- 198.16 mm2 v 4.39 +/- 9.50 mm2) (P < .025). The amount of coronary calcium did not change as a result of the PTCA procedure (+2.72 +/- 22.31 mm2 v -4.81 +/- 7.82 mm2) (P = NS). The rate of progression of calcification was not greater in restenosed versus nonrestenosed patients (1.78 +/- 3.32 mm2/month v 0.09 +/- 0.19 mm2/mo) (P = NS). Site-specific coronary calcification as determined by EBCT appeared to be predictive of patients with an increased likelihood to restenose after PTCA. Further studies are needed to verify these observations in a considerably larger patient population.

Angioplasty, Balloon, Coronary↗

PubMed1994

Coronary-artery vasoconstriction induced by cocaine, cigarette smoking, or both.

BACKGROUND: In humans, the use of cocaine and cigarette smoking each increase the heart's metabolic need for oxygen but may also decrease the supply of oxygen. As cocaine abuse has proliferated, cocaine-associated chest pain, myocardial infarction, and sudden death have occurred, especially among smokers. We assessed the influence of intranasal cocaine and cigarette smoking, alone and together, on myocardial oxygen demand and coronary arterial dimensions in subjects with and subjects without coronary atherosclerosis. METHODS: In 42 smokers (28 men and 14 women; age, 34 to 79 years; 36 with angiographically demonstrable coronary artery disease), we measured the product of the heart rate and systolic arterial pressure (rate-pressure product) and coronary arterial diameters before and after intranasal cocaine at a dose of 2 mg per kilogram of body weight (n = 6), one cigarette (n = 12), or intranasal cocaine at a dose of 2 mg per kilogram followed by one cigarette (n = 24). RESULTS: No patient had chest pain or ischemic electrocardiographic changes after cocaine use or smoking. The mean (+/- SE) rate-pressure product increased by 11 +/- 2 percent after cocaine use (n = 30, P < 0.001), by 12 +/- 4 percent after one cigarette (n = 12, P = 0.021), and by 45 +/- 5 percent after both cocaine use and smoking (n = 24, P < 0.001). As compared with base-line measurements, the diameters of nondiseased coronary arterial segments decreased on average by 7 +/- 1 percent after cocaine use (P < 0.001), by 7 +/- 1 percent after smoking (P < 0.001), and by 6 +/- 2 percent after cocaine use and smoking (P < 0.001). The diameters of diseased segments decreased by 9 +/- 2 percent after cocaine use (n = 18, P < 0.001), by 5 +/- 5 percent after smoking (n = 12, P = 0.322), and by 19 +/- 4 percent after cocaine use and smoking (n = 12, P < 0.001). The increase in the rate-pressure product and the decrease in the diameters of diseased segments caused by cocaine use and smoking together were greater (P < 0.001 and P = 0.037, respectively) than the changes caused by either alone. CONCLUSIONS: The deleterious effects of cocaine on myocardial oxygen supply and demand are exacerbated by concomitant cigarette smoking. This combination substantially increases the metabolic requirement of the heart for oxygen but simultaneously decreases the diameter of diseased coronary arterial segments.

Adult↗

PubMed1994

Assessment of cardiac volumes and left ventricular mass by cine computed tomography before and after mitral balloon commissurotomy.

We used cine computed tomography (CT) to determine whether decreased mitral valve gradients and pulmonary artery pressures resulted in decreased right ventricular and atrial volumes after percutaneous mitral balloon commissurotomy (MBC). In patients treated for severe mitral stenosis, previous studies have shown that after the mitral valve gradient decreases, the left atrial volume is reduced and left ventricular stroke volume is increased. The effects of commissurotomy on right heart chamber sizes have been difficult to assess with angiography and echocardiography. Moreover, in follow-up studies performed after surgery, changes in cardiac chamber volumes occurring after the mitral valve gradient and pulmonary pressure are reduced are confounded by the effects of thoracotomy. Our group has previously demonstrated that cine CT can accurately measure both left and right cardiac chamber volumes. We studied 11 female patients before, immediately after, and at 1 year after MBC, and 9 female control subjects of comparable age. To assess cardiac chamber volumes, we used cine CT. To assess the effects of MBC, we used cardiac catheterization and Doppler echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗

PubMed1994

Effect of adenosine antagonism on metabolically mediated coronary vasodilation in humans.

OBJECTIVES: This study was performed to assess the importance of adenosine in mediating metabolic coronary vasodilation during atrial pacing stress in humans. BACKGROUND: Numerous animal studies have examined the role of adenosine in the regulation of coronary blood flow, with inconsistent results. METHODS: The effect of the adenosine antagonist aminophylline (6 mg/kg body weight intravenously) on coronary functional hyperemia during rapid atrial pacing was determined in 12 patients. The extent of inhibition of adenosine vasodilation was assessed using graded intracoronary adenosine infusions before and after aminophylline administration in seven patients. Coronary blood flow changes were measured with a 3F intracoronary Doppler catheter. RESULTS: After aminophylline administration, the increase in coronary flow velocity during adenosine infusions was reduced from 84 +/- 48% (mean +/- SD) to 21 +/- 31% above control values (p < 0.001) at 10 micrograms/min and from 130 +/- 39% to 59 +/- 51% above control values (p < 0.001) at 40 micrograms/min. During rapid atrial pacing under control conditions, coronary blood flow velocity increased by 26 +/- 16%. The flow increment during paced tachycardia after aminophylline (23 +/- 10%) was unchanged from the control value, despite substantial antagonism of adenosine coronary dilation by aminophylline. CONCLUSIONS: These data suggest that adenosine does not play an important role in the regulation of coronary blood flow in response to rapid atrial pacing in humans.

Adenosine↗

PubMed1994

Prediction of change in mitral valve area after mitral balloon commissurotomy using cine computed tomography.

RATIONALE AND OBJECTIVES: Mitral balloon commissurotomy (MBC) can successfully increase the mitral valve area (MVA) in mitral stenosis, but the outcome is variable. In multicenter studies, qualitative echocardiographic scores obtained before MBC are only weakly predictive of the increase in MVA after MBC. METHODS: To evaluate whether the change in MVA after MBC can be predicted by evaluating mitral valve morphology using cine computed tomography (CT), we studied 12 women with mitral stenosis and 11 female control subjects. RESULTS: In the patients with mitral stenosis, MVA increased from 1.13 +/- 0.24 to 1.93 +/- 0.56 cm2 (P < .0001) after MBC. A standard echocardiographic score assessment of mitral valve morphology before MBC was not associated with the change in MVA after MBC in these patients (P > .20). However, the total mitral valve morphology score evaluated by cine computed tomography was strongly associated with the change in MVA after MBC (r = -.87; P < .0005). In addition, the individual morphologic characteristics of mitral valve mobility (P < .0025), leaflet thickness (P < .05), and subvalvular disease (P < .05) were significant predictors of the change in MVA after MBC. CONCLUSION: Cine computed tomography may be useful for predicting immediate increases in MVA in patients after MBC and may be helpful for preoperative assessment of these patients.

Catheterization↗

PubMed1994

Lumen centerline detection in complex coronary angiograms.

We have developed a method for lumen centerline detection in individual coronary segments that is based on simultaneous detection of the approximate positions of the left and right coronary borders. This approach emulates that of a clinician who visually identifies the lumen centerline as the midline between the simultaneously-determined left and right borders of the vessel segment of interest. Our lumen centerline detection algorithm and two conventional centerline detection methods were compared to carefully-defined observer-identified centerlines in 89 complex coronary images. Computer-detected and observer-defined centerlines were objectively compared using five indices of centerline position and orientation. The quality of centerlines obtained with the new simultaneous border identification approach and the two conventional centerline detection methods was also subjectively assessed by an experienced cardiologist who was unaware of the analysis method. Our centerline detection method yielded accurate centerlines in the 89 complex images. Moreover, our method outperformed the two conventional methods as judged by all five objective parameters (p < 0.001 for each parameter) and by the subjective assessment of centerline quality (p < 0.001). Automated detection of lumen centerlines based on simultaneous detection of both coronary borders provides improved accuracy in complex coronary arteriograms.

Algorithms↗

PubMed1993

Acute effect of cigarette smoking on the coronary circulation: constriction of epicardial and resistance vessels.

OBJECTIVES: This study was performed to determine the acute effect of cigarette smoking on proximal and distal epicardial conduit and coronary resistance vessels. BACKGROUND: Cigarette smoking causes constriction of epicardial arteries and a decrease in coronary blood flow in patients with coronary artery disease, despite an increase in myocardial oxygen demand. The role of changes in resistance vessel tone in the acute coronary hemodynamic effect of smoking has not been examined. METHODS: Twenty-four long-term smokers were studied during cardiac catheterization after vasoactive medications had been discontinued. The effect of smoking one cigarette 10 to 15 mm long on proximal and distal conduit vessel segments was assessed before and immediately after smoking and at 5, 15 and 30 min after smoking (n = 8). To determine the effect of smoking on resistance vessels, coronary flow velocity was measured in a nonobstructed artery with a 3F intracoronary Doppler catheter before and for 5 min after smoking (n = 8). Eight patients were studied without smoking to control for spontaneous changes in conduit arterial diameter (n = 5) and resistance vessel tone (n = 3). RESULTS: The average diameter of proximal coronary artery segments decreased from 2.56 +/- 0.12 mm (mean +/- SEM) before smoking to 2.41 +/- 0.09 mm 5 min after smoking (-5 +/- 2%, p < 0.05). Distal coronary diameter decreased from 1.51 +/- 0.07 to 1.39 +/- 0.06 mm (-8 +/- 2%, p < 0.01). Marked focal vasoconstriction after smoking was observed in two patients. Coronary diameter returned to baseline by 30 min after smoking. There was no change in vessel diameter in control patients. Despite a significant increase in the heart rate-mean arterial pressure product, coronary flow velocity decreased by 7 +/- 4% (p < 0.05) and coronary vascular resistance increased by 21 +/- 4% (p < 0.01) 5 min after smoking. There was no change in these variables in the control subjects. CONCLUSIONS: Smoking causes immediate constriction of proximal and distal epicardial coronary arteries and an increase in coronary resistance vessel tone, despite an increase in myocardial oxygen demand. These acute coronary hemodynamic effects may contribute to the adverse cardiovascular consequences of cigarette smoking.

Analysis of Variance↗

PubMed1993

Effect of increases in heart rate and arterial pressure on coronary flow reserve in humans.

OBJECTIVES: The objective of this study was to determine the effect of increases in heart rate and arterial pressure on maximal pharmacologic coronary blood flow reserve. BACKGROUND: Coronary flow reserve measurements are useful in assessment of the physiologic significance of coronary lesions. However, animal studies suggest that alterations in hemodynamic status may influence coronary flow reserve independent of coronary stenosis. METHODS: Coronary flow reserve was measured during cardiac catheterization with the use of a 3F coronary Doppler catheter and intracoronary papaverine. Flow reserve was measured under control conditions and during increases in heart rate produced by atrial pacing (18 patients) or during elevation of arterial pressure by intravenous phenylephrine infusion (9 patients) with intracoronary alpha-adrenergic blockade by phentolamine. RESULTS: Coronary flow reserve progressively decreased from 3.7 +/- 0.9 (mean +/- SD) at the rate of 71 +/- 8 beats/min at rest to 3.0 +/- 0.6 during pacing at 100 beats/min and to 2.6 +/- 0.5 during pacing at 120 beats/min. Flow reserve decreased because of a progressive increase in rest coronary flow velocity during pacing (122 +/- 16% of control value at 100 beats/min, 139 +/- 16% of control value at 120 beats/min), whereas papaverine hyperemia peak velocity remained unchanged. Flow reserve decreased with pacing tachycardia whether the initial flow reserve was normal or depressed. Mean arterial pressure increased from 95 +/- 12 mm Hg to 130 +/- 8 mm Hg during intravenous phenylephrine infusion and to 123 +/- 10 mm Hg during combined intravenous phenylephrine and intracoronary phentolamine infusions. Coronary flow reserve was not affected by the blood pressure increases (control value 4.3 +/- 1.0, phenylephrine 4.4 +/- 1.5, phenylephrine and phentolamine 4.4 +/- 2.0). CONCLUSIONS: Sudden increases in heart rate but not mean arterial pressure lead to a substantial reduction in maximal coronary blood flow reserve. These data suggest that the diagnostic utility of all flow reserve measurement techniques might be improved by standardization of heart rate during measurement or extrapolation of the measured flow reserve to that expected at a reference heart rate.

Blood Flow Velocity↗

PubMed1992

Simultaneous measurement of coronary flow reserve by left anterior descending coronary artery Doppler and great cardiac vein thermodilution methods.

OBJECTIVES: The objective of this study was to compare left anterior descending coronary artery Doppler blood flow velocity and great cardiac vein thermodilution blood flow measurements of coronary flow reserve and submaximal coronary vasodilation in humans. BACKGROUND: Reported maximal coronary flow reserve values obtained with the coronary venous thermodilution method are lower than those obtained with other measurement methods. METHODS: Thermodilution measurements of great cardiac vein flow in 11 subjects were compared with simultaneous Doppler measurements of changes in left anterior descending coronary flow velocity after intracoronary administration of papaverine, nitroglycerin, iohexol and intravenous administration of dipyridamole. RESULTS: Coronary flow reserve (papaverine peak/rest flow ratio) was 3.7 +/- 1.7 (mean +/- SD) by the Doppler method and 2.0 +/- 0.7 by the thermodilution technique (p less than 0.001). Thermodilution flow changes were also smaller than Doppler-measured changes during submaximal vasodilation and during prolonged coronary dilation after dipyridamole administration. CONCLUSIONS: Coronary flow reserve and submaximal flow increases measured with the thermodilution method were consistently and substantially smaller than Doppler-derived measurements. This discrepancy has important implications for the comparison of coronary flow reserve measurements performed with the use of different techniques.

Blood Flow Velocity↗

PubMed1992

Histological and angiographic effects of a pulsed holmium:YAG laser in normal and atherosclerotic human coronary arteries and aorta.

OBJECTIVE: The aims were (1) To determine the histological and angiographic effects of holmium:YAG laser energy delivered through clinical multifibre laser catheters on fresh cadaveric coronary arteries; and (2) to relate the placement of optical fibres in the catheter to patterns of tissue ablation in cadaveric aorta. METHODS: Eight fresh cadaveric hearts and segments of aorta were used. Hearts were mounted on a new pressure perfusion device. The laser catheter was delivered over a guidewire in the lumen until it met an area of resistance. The coronary artery lumen was perfused at approximately 100 mm Hg mean pressure. These arterial areas were identified on angiography, marked, and then exposed to laser energy in the range 600-3000 mJ.mm-2. Normal and atherosclerotic areas of fresh cadaveric aortic strips were exposed to increasing laser energies using either constant or increasing fluence. Coronary arteries were pressure perfused with formalin for 18-24 h at 100 mm Hg mean pressure, and aortic strips were immersed in 5% formalin. Light and scanning electron microscopy studies were carried out. RESULTS: There were no perforations or dissections by angiography in the fresh coronary arteries. One of 15 normal coronary artery segments and 10 of 16 of the pressure perfused, fixed, atherosclerotic coronary artery segments showed thermal changes associated with atherosclerotic plaque ablation. In aortic tissue, thermal effects extended 0 to 0.6 mm lateral to the ablated crater. Acoustic effects were seen only in the aortic strips after ablation at fluences > 1000 mJ.mm-2. The "dead spaces" around the optical fibres in the catheter resulted in significant amounts of coagulated tissue fragments remaining in the crater. CONCLUSIONS: Holmium:YAG laser energy delivered through multifibre catheters ablated atherosclerotic tissue in coronary arteries with minimal damage to the normal walls. The cadaveric coronary artery perfusion apparatus is useful for assessing catheter delivery and mobility and the effects of laser energy on the coaxially orientated normal and atherosclerotic coronary arterial wall.

Aorta↗

PubMed1991

Cocaine-induced myocardial infarction in patients with normal coronary arteries.

OBJECTIVE: To review the reported cases of myocardial infarction temporally related to recreational and topical anesthetic use of cocaine, with special regard for underlying etiologic factors in patients subsequently found to have normal coronary arteries. DATA SOURCES: Personal records of three cases and a comprehensive literature review using MEDLINE and supplemented by Index Medicus and the bibliographies of case reports. DATA SYNTHESIS: A total of 114 cases of cocaine-induced myocardial infarction were identified. The coronary anatomy was defined by angiography or autopsy in 92 patients, 38% of whom had normal coronary arteries. In these 35 patients (average age, 32; range, 21 to 60 years), myocardial infarction typically involved the anterior left ventricular wall (77%). Moderate cigarette smoking with one or fewer associated coronary risk factors was prevalent (68%). Focal coronary vasospasm was shown convincingly in only two cases. Intracoronary thrombus was initially found on 9 of 11 angiograms (82%) done within 12 hours of the myocardial infarction. Experimental evidence suggests that cocaine has direct and indirect sympathomimetic effects on vascular smooth muscle, attenuates endothelium vasodilator capacity, exerts a potent depressant effect on cardiac myocytes, and promotes atherogenesis. CONCLUSIONS: Cocaine-induced myocardial infarction in patients with normal coronary arteries probably involves adrenergically mediated increases in myocardial oxygen consumption, vasoconstriction of large epicardial arteries or small coronary resistance vessels, and coronary thrombosis. Accelerated atherosclerosis and impairment of endothelium vasodilator function may occur after chronic cocaine use.

Adult↗

PubMed1991

Comparison of coronary vasodilation with intravenous dipyridamole and adenosine.

Although both intravenous dipyridamole and adenosine have been used to produce coronary vasodilation during cardiac imaging, the relative potency of the commonly administered doses of these agents has not been evaluated. Accordingly, the coronary and systemic hemodynamic effects of intravenous adenosine (140 micrograms/kg per min) and intravenous dipyridamole (0.56 mg/kg over 4 min) were compared with a maximally dilating dose of intracoronary papaverine in 15 patients. Coronary blood flow responses were assessed using a Doppler catheter in a nonstenotic coronary artery. The protocol was discontinued in two patients because of transient asymptomatic atrioventricular (AV) block during adenosine infusion. The mean heart rate increased more with adenosine (11 +/- 9 beats/min) and dipyridamole (11 +/- 7 beats/min) than with papaverine (4 +/- 3 beats/min, p less than 0.05 vs. adenosine and papaverine). The mean arterial pressure decreased less with dipyridamole (-10 +/- 3 mm Hg) and papaverine (-9 +/- 4 mm Hg) than with adenosine (-16 +/- 5 mm Hg, p less than 0.01 vs. dipyridamole and papaverine). The peak/rest coronary blood flow velocity ratio was greater with papaverine (3.9 +/- 1.1) than with adenosine (3.4 +/- 1.2, p less than or equal to 0.05 vs. papaverine) or dipyridamole (3.1 +/- 1.2, p less than 0.01 vs. papaverine). A larger decrease in coronary resistance as measured by the coronary vascular resistance index occurred with papaverine (0.25 +/- 0.06) and adenosine (0.26 +/- 0.09) than with dipyridamole (0.31 +/- 0.10, p less than 0.01 vs. papaverine, p less than 0.05 vs. adenosine).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

PubMed1991

A prospective study of the incidence and natural history of femoral vascular complications after percutaneous transluminal coronary angioplasty.

Over a 14-month period patients undergoing 144 percutaneous transluminal coronary angioplasty procedures were evaluated for the presence of complications at the femoral puncture site. After percutaneous transluminal coronary angioplasty each patient was examined by a surgeon, and then a color-flow duplex scan of the groin was obtained. On the initial scan eight pseudoaneurysms, three arteriovenous fistulas, one combined arteriovenous fistula-pseudoaneurysm, and one thrombosed superficial femoral artery were detected for a major vascular complication rate of 9%. Pseudoaneurysm formation was associated with the use of heparin after removal of the arterial sheath. Seven pseudoaneurysms (initial extravascular cavity size range 1.3 to 3.5 cm) were followed with weekly duplex scans, and all thrombosed spontaneously within 4 weeks of detection. The three patients with isolated arteriovenous fistulas were each followed for at least 8 weeks, and the arteriovenous fistulas persisted. Early surgical intervention for postcatheterization femoral pseudoaneurysms is usually unnecessary as thrombosis often occurs spontaneously. We would advocate an operative approach for pseudoaneurysms that are symptomatic, expanding, or associated with large hematomas. Iatrogenic femoral arteriovenous fistulas should be considered for elective repair, but this may be delayed for several weeks without adverse sequelae.

Adult↗

PubMed1991

Physiological assessment of sensitivity of noninvasive testing for coronary artery disease.

The sensitivity of three noninvasive tests for coronary artery disease was assessed by means of quantitative indexes of disease severity in three different groups of patients. The overall population consisted of 110 subjects with limited coronary artery disease and no myocardial infarction. Planar dipyridamole-201Tl scintigraphy was evaluated in 31 patients, computer-assisted exercise treadmill in 28, and high-dose dipyridamole echocardiography testing in 51. Sensitivity was assessed by rigorous gold standards to define disease severity, such as measurement of minimum cross-sectional area and percent area of stenosis, by quantitative computerized coronary angiography (Brown/Dodge method). On the basis of the results of previous studies, the presence of physiologically significant coronary artery disease was indicated by a stenotic minimum cross-sectional area (MCSA) of less than 2.0 mm2 or a greater than 75% area of stenosis. With MCSA as the gold standard, dipyridamole-201Tl scintigraphy, computerized exercise treadmill, and dipyridamole echocardiography testing showed sensitivities of 52%, 54%, and 61%, respectively, in the three different patient cohorts enrolled. With percent area of stenosis as the gold standard, the sensitivity figures obtained for dipyridamole-201Tl, computerized exercise treadmill, and dipyridamole echocardiography testing were 64%, 54%, and 69%, respectively. For each of the three tests, sensitivity increased with increasing lesion severity. Sensitivity was also better in patients with left anterior descending coronary (LAD) disease when compared with patients with left circumflex or right coronary artery disease. Results of these studies, which were obtained with more strict patient selection criteria and by more rigorous gold standards than previous studies, demonstrate that in patients with limited coronary artery disease none of the tests evaluated is definitely superior in sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗