Effect Of Coronary Angioplasty Research Articles

Effects of coronary angioplasty on left ventricular diastolic filling in patients with old myocardial infarction: A study with pulsed Doppler echocardiography

To examine the effects of percutaneous transluminal coronary angioplasty (PTCA) on left ventricular diastolic filling in patients with an old myocardial infarction, transmitral flow velocity pattern was measured using pulsed Doppler echocardiography before and after PTCA for the peak early diastolic filling velocity (E) and the ratio of the early diastolic filling to peak atrial filling velocities (E/A ratio) in 73 patients with coronary artery disease. These patients were classified into three groups: 34 patients without previous myocardial infarction (no MI group), 16 patients with an old myocardial infarction in whom a non-infarct-related vessel was reperfused by PTCA (MI-1 group), and 23 patients with an old myocardial infarction in whom the infarct-related vessel was reperfused by PCTA (MI-2 group). The degree of improvement in left ventricular diastolic filling was calculated using the values before PTCA as controls. The % increases in E and E/A ratio were 20 +/- 15 and 25 +/- 19%, respectively, in the no MI group and 27 +/- 20 and 18 +/- 16%, respectively, in the MI-1 group and there was no significant difference between these groups. The % increases in E and E/A ratio in the MI-2 group were 7 +/- 19 and 6 +/- 17%, respectively, and were significantly (P less than 0.05) less than those in the no MI and MI-1 groups. An increase in E, E/A ratio or both by 20% or more was observed in 21 of the 34 (62%) patients of the no MI group, in 10 of the 16 (63%) patients of the MI-1 group and in six of the 23 (26%) patients of the MI-2 group. Thus, reperfusion of a non-infarct-related vessel in patients with an old myocardial infarction improves left ventricular diastolic filling to the same degree and with the same frequency as in patients without myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of coronary angioplasty on electrocardiographic changes in patients with unstable angina secondary to left anterior descending coronary artery disease

The effect of semiemergent percutaneous transluminal coronary angioplasty on clinical and electrocardiographic (ECG) variables was assessed in 76 patients with unstable angina secondary to an isolated severe proximal left anterior descending coronary artery stenosis. All patients manifested symmetric T wave inversion in two or more anterior ECG leads. Wall motion abnormalities were present in 37 patients on ventriculography before dilation.Angioplasty was successful in 70 patients (92%), resulting in a reduction in luminal diameter stenosis from 91 ± 8% to 21 ± 6%, with no major acute procedure-related complications observed. The other six patients underwent semiurgent (< 48 h) coronary artery bypass surgery and three patients experienced a myocardial infarction (before bypass surgery in two). Serial ECGs revealed complete resolution of ST-T wave changes in 51% of patients at 14 weeks and in 90% at 28 weeks. In contrast, prolongation of the corrected QT interval, which was present in 16 patients (8%), normalized within 48 h of successful angioplasty. Twelve of these 16 patients with a prolonged QT interval had nonocclusive thrombus formation and poor collateral circulation on angiography.Patients were followed up for 6 to 43 months (mean 23 ± 10). Angiographic evidence of restenosis was present in 34% of patients, all of whom underwent a successful second or third procedure. One death occurred at 8 months alter successful aagiophsty. Wall motion abnormalities had completely resolved in 13 of 15 patients who underwent repeat ventriculography, at which time 10 had a normal ECG.This study demonstrates that ECG changes may persist for up to 7 months in patients who undergo successful angioplasty for severe left anterior descending coronary artery disease and unstable angina. Semiemergent angioplasty was associated with a high initial success rate and excellent long-term outcome.

Augmented myocardial perfusion reserve after coronary angioplasty quantified by positron emission tomography with H215O

Effects of coronary angioplasty on myocardial flow reserve have been difficult to characterize noninvasively because conventional imaging techniques cannot quantitate blood flow in absolute terms. The effects of coronary angioplasty on myocardial perfusion and perfusion reserve were delineated with positron emission tomography and oxygen-15-labeled water (H215O) in 13 patients before and after single vessel angioplasty. In 11 patients, angioplasty was successful (minimal cross-sectional area increased from 0.60 ± 0.59 to 3.45 ± 1.09 mm2, p < 0.001). In these patients, regional H215O radioactivity (the ratio of nutritional perfusion in regions distal to the stenosis compared with regions supplied by angiographically normal arteries) at rest before angioplasty was 55 ± 22% of peak myocardial radioactivity and did not increase significantly afterward (70 ± 16%, p = NS). However, after administration of intravenous dipyridamole, hyperemic perfusion in regions distal to a stenosis averaged only 39 ± 18% of peak myocardial counts before angioplasty, but increased to 66 ± 22% after angioplasty (p < 0.02). Perfusion reserve in the two patients in whom angioplasty was angiographically unsuccessful showed no change.Quantitative estimates of perfusion in absolute rather than relative terms were obtained with positron emission tomographic data from seven of the patients with successful angioplasty. At rest, perfusion in regions distal to a stenosis was not different from the values in regions supplied by normal coronary arteries (1.54 ± 0.54 compared with 1.46 ± 0.38 ml/g per min, p = NS). After dipyridamole, however, perfusion distal to a stenosis increased to only 64 ± 14% of flow observed in normal regions (1.98 ± 0.97 compared with 3.24 ± 1.92 ml/g per min, p < 0.04). In contrast, after angioplasty, hyperemic perfusion unproved in regions supplied by vessels subjected to angioplasty with values similar to those in regions supplied by normal vessels (4.36 ± 1.61 compared with 4.04 ± 1.28 ml/g per mm). Eight patients, all without symptoms of recurrent ischemia, were studied again an average of 7.5 months after angioplasty. In all, the enhanced perfusion reserve capacity was maintained.The results obtained indicate that angiographically successful coronary angioplasty improves myocardial perfusion reserve and demonstrate the utility of positron emission tomography with H215O for quantitative delineation of the efficacy of specific means of revascularization on nutritional perfusion and perfusion reserve.

The Effects of Coronary Angioplasty on Nitroglycerin‐Induced Augmentation of Regional Myocardial Blood Flow

Percutaneous transluminal coronary angioplasty (PTCA) may improve coronary vasomotor responses after relief of flow limiting luminal narrowings. To evaluate the effects of PTCA on nitro‐glycerin‐induced augmentation of coronary blood flow, great cardiac vein (thermodilution) blood flow and systemic hemodynamic responses to low (50 meg) and high (200 meg) dose intracoronary nitroglycerin (NTG) before and after PTCA were measured in 20 patients undergoing left anterior descending artery (LAD) balloon dilatation. Before PTCA, low dose NTG increased great vein flow 44 ±31% (from 56 ± 21 to 81 ± 33 mL/min, P &lt; 0.01). High dose NTG increased great vein flow 55 + 30% (56 ± 23 to 87 ± 38 mL/min, P &lt; 0.01). PTCA reduced LAD stenosis (79 ± 13 to 20 ± 9%, P &lt; 0.01) and translesional pressure gradient (49 ± 10 to 15 ± 13 mmHg, P &lt; 0.01) increasing post‐PTCA basal great vein flow 45% (56 ± 21 mL/min to 81 ±27 mL/min, P &lt; 0.01).After PTCA, low dose NTG increased great vein flow only 26 ± 23% (81 ± 27 to 101 ± 39mL/min, P &lt; 0.01; P &lt; 0.05 versus 44 ± 31% before PTCA). The high dose NTG‐induced coronary hy‐peremic responses were unchanged after PTCA (55 ± 30, 55 ± 34%, P = ns). When compared to dose related NTG hyperemic responses in 10 patients with normal LAD, the post‐PTCA responses remained attenuated.These data indicate that NTG‐induced augmentation of coronary blood flow remains unchanged or attenuated and does not appear to be improved by PTCA. These findings should be considered when evaluating pharmacological coronary blood flow responses after PTCA. These data also suggest that epicardial coronary resistance plays a limited role in NTG‐induced augmentation of coronary blood flow inpatients with atherosclerotic coronary disease. (J Interven Cardiol 1988:1:2)

Assessment of myocardial perfusion in humans by contrast echocardiography. I. Evaluation of regional coronary reserve by peak contrast intensity

Myocardial contrast echocardiography was performed during coronary angiography with 2 ml of sonicated meglumine diatrizoate sodium 76% (meglumine) in 40 patients (ranging in age from 25 to 79 years) before and 10 to 15 s after intracoronary injection of papaverine, 8 mg into the right coronary artery (n = 43) and 10 mg into the left (n = 46). The same protocol was repeated in 17 patients 5 to 10 min after completion of coronary angioplasty. In 13 patients with normal coronary angiograms, peak contrast intensity corrected for background myocardial intensity was measured in 36 regions and was found to increase after papaverine from 36 ± 16 to 55 ± 22 U (p < 0.001). In contrast, in the 27 patients with angiographic evidence of coronary artery disease, peak intensity in 64 regions remained unchanged after papaverine (35 ± 22 versus 36 ± 23 U). An increase in peak intensity ≥10 U was 80% sensitive and 92% specific for coronary artery disease. After successful coronary angioplasty, peak intensity in the involved regions improved significantly (p < 0.001) during baseline contrast injections (from 32 ± 16 to 50 ± 25 U) as well as in the postpapaverine contrast injections (from 30 ± 12 to 60 ± 26 U). In conclusion, measurement of peak contrast intensity after intracoronary injections of sonicated meglumine provides a relative index of myocardial perfusion that allows assessment of regional coronary reserve in patients with coronary artery disease. This may be of particular value in evaluating the immediate effects of coronary angioplasty on myocardial perfusion.

Quantitative analysis of thallium-201 uptake and washout before and after transluminal coronary angioplasty

Transluminal coronary angioplasty has become an important therapeutic modality in the treatment of coronary artery disease. The effects of coronary angioplasty on regional myocardial perfusion have been reported in only a small series of patients, employing subjective analysis of thallium-201 perfusion scintigrams. Thus, we studied 61 patients with quantitative analysis of thallium-201 uptake and washout before and after undergoing angioplasty. Prior to angioplasty, there were 105 areas in 47 patients with abnormal thallium-201 uptake during exercise, with a mean uptake of 49 ± 1.3%. The uptake of thallium-201 in these same areas increased to 71.3 ± 1.9% post angioplasty ( P < 0.0001), and 68 (65%) of the areas showing abnormal uptake returned to normal. Abnormalities in washout of thallium-201 before angioplasty were seen more frequently than in uptake (150 vs 105 areas, P < 0.05), with 8 patients having abnormal washout in the presence of totally normal uptake. Thallium-201 washout in the abnormal areas improved from 16 ± 2.8 pre angioplasty to −23 ± 1.8% post angioplasty ( P < 0.001). Normalization resulted in 6 of the 8 patients with exclusively washout abnormality. Residual abnormalities in uptake and/or washout were seen in 53% of the patients, usually in areas with prior myocardial infarction or supplied by a vessel with significant stenosis which did not undergo angioplasty. Improved thallium-201 uptake and washout corresponded to reductions in percent coronary area stenosis (89 ± 1.0 to 36 ± 2.0%, P < 0.001) and transstenotic pressure gradient (42 ± 3.0 to 9.0 ± 2.0 mm Hg, P < 0.001). Thus, quantitative analysis of thallium-201 uptake and washout provided objective evidence for improved myocardial perfusion after coronary angioplasty. Due to a fairly high prevalence of residual perfusion abnormalities after this procedure, optimal assessment of benefits requires quantitative comparison of thallium uptake and washout before and after coronary angioplasty.

Contrast echocardiography for evaluation of myocardial perfusion: Effects of coronary angioplasty

Assessment of viable myocardium before and after interventional therapy has become a critical issue in modern cardiology. This report describes a new contrast echocardiographic technique using conventional two-dimensional imaging during direct intracoronary injections of small volumes (1.5 to 2.0 cc) of sonicated Renografin-76. Contrast echocardiography was performed before and after coronary angioplasty in seven patients with single vessel coronary artery disease. Before angioplasty a contrast (that is, perfusion) defect was noted in all seven patients. This defect correlated with the anatomic distribution of the epicardial coronary stenosis. After angioplasty the mean gradient across the stenotic lesion decreased from 52 +/- 11 to 13 +/- 14 mm Hg (p less than 0.01) in association with a fall in the mean diameter of the lesion from 84 +/- 8 to 29 +/- 13% (p less than 0.001). Increased myocardial perfusion to the area of "contrast defect" was demonstrated in only five of the seven patients, despite hemodynamically and angiographically successful angioplasty. Thus, contrast echocardiographic techniques performed during interventional therapy and used in conjunction with standard coronary angiographic procedures may provide additional physiologic information regarding regional myocardial perfusion after attempts at revascularization.

The effects of coronary angioplasty and reperfusion on distribution of myocardial flow.

To assess the effects of angioplasty (PTCA) and intracoronary streptokinase (ICSK) on relative myocardial perfusion, we administered 99mTc-macroaggregated albumin (MAA) to the uninvolved coronary artery before successful PTCA in 33 patients and before successful infusion of ICSK in eight patients and of 111In-MAA into the same vessel after the intervention. In 10 patients who underwent PTCA, MAA was injected into the involved, instrumented coronary artery. Computer-processed images were acquired in registry and compared. Similar scintigraphic studies were performed in six control patients and in 11 in whom planned interventions were not performed or were unsuccessful. Distribution of MAA was also compared with angiographic results and with the distribution of 201Tl on images obtained in patients at rest or on redistribution images obtained before and soon after intervention in 22 patients. In control patients and those studied after aborted or unsuccessful intervention, scintigraphic results showed excellent correlation with the angiographic anatomy and were without serial change. When MAA was injected into the uninvolved vessel, the scintigram revealed evidence of collateral perfusion with retraction of the perfusion zone from that of the involved coronary in 19 of 33 patients undergoing PTCA and in three of eight of those receiving ICSK. When MAA was injected into the involved artery, a relative increase in perfusion was seen in eight of 10 patients after PTCA. Although 30 patients demonstrated scintigraphic evidence of collateral vessels, only 10 patients had angiographic evidence of collateral circulation before intervention. The distribution of 201Tl demonstrated little change in its global pattern and regions previously supplied by collaterals were generally well perfused after intervention. Coronary collateral perfusion may be inapparent angiographically and regress rapidly after angioplasty or reperfusion. Native perfusion is generally and quickly restored after successful PTCA or ICSK infusion, which obviates the need for collaterals. After intervention, the distribution of total perfusion may not change, but its regional source may demonstrate beneficial alterations, shifting from collateral to native circulation.