Cardiac release of chemoattractants after ischaemia induced by coronary balloon angioplasty.

OBJECTIVE--To investigate the release of chemoattractants after myocardial ischaemia during balloon angioplasty. DESIGN--Sampling of femoral arterial and coronary sinus blood before and immediately after the first balloon inflation during angioplasty. In a study group of 16 patients the balloon was kept expanded for two minutes, whereas in a control group of eight patients the first balloon inflation was brief (< 10 s). MAIN OUTCOME MEASURES--Chemotaxis of neutrophils from healthy donors towards patient plasma (Boyden chamber), superoxide anion production by normal neutrophils after incubation with patient plasma (cytochrome C reduction). RESULTS--In the study group, coronary sinus plasma after balloon deflation was more chemoattractive to normal neutrophils (median relative increase 24% (quartiles: 4%, 45%), p = 0.008) and induced a higher superoxide anion production in normal neutrophils (44% (10%, 97%), p = 0.013) than arterial plasma. Concomitantly, the degree of activation of patient neutrophils was increased in coronary sinus blood compared with arterial blood, as shown by an increased proportion of neutrophils reducing nitro-blue tetrazolium (21% (9%, 38%), p = 0.006) and a decreased neutrophil filter-ability (-16%(-3%, -40%), p = 0.003) in coronary sinus blood. In the study group before balloon inflation and in the control group before and after balloon inflation differences between arterial and coronary sinus blood were not significant. Signs of ischaemia (lactate release, ST segment changes) were only detected in the study group. CONCLUSION--After transient myocardial ischaemia during balloon angioplasty there is a local release of chemoattractants, associated with neutrophil activation.     

Plasma-mediated stimulation of neutrophil superoxide anion production during coronary artery bypass grafting: role of endothelin-1.

BACKGROUND: Activation of polymorphonuclear neutrophils (PMN) and subsequent release of free oxygen radicals, including the superoxide anion (O2-) has been shown to result in postischaemic myocardial dysfunction during coronary artery bypass grafting (CABG). Several neutrophil-oriented stimuli are known to be released from myocardium during ischaemia and reperfusion. Release of endothelin-1 has been documented during CABG. The aim of the current study was to evaluate plasma-mediated neutrophil stimulation and to verify whether endothelin-1, known to be a stimulus for PMN, is involved in plasma-mediated stimulation of PMN during coronary artery bypass grafting. METHODS: Plasma samples from peripheral artery, peripheral vein, and coronary sinus were obtained from 21 patients undergoing CABG before aortic clamping (global ischaemia), immediately after beginning reperfusion, and 30 min after reperfusion as well as from healthy controls. Plasma was incubated with PMN isolated from healthy donors preincubated in the presence of saline or specific endothelin-1 receptor antagonist (ET-A). PMN O2- production was measured spectrophotometrically. RESULTS: Plasma samples taken from the coronary sinus at the beginning of reperfusion were capable of higher stimulation of neutrophil superoxide anion production (24.2 +/- 2.0 nmol/5 x 10(6)PMN/30 min) than plasma obtained before reperfusion (15.6 +/- 1.5; p < 0.05) or plasma taken from peripheral artery (17.1 +/- 1.7; p < 0.05). Preincubation of PMN with endothelin-1 receptor antagonist decreased superoxide anion production by cells exposed to plasma taken from coronary sinus at the beginning of reperfusion (17.6 +/- 2.0, p < 0.05). CONCLUSIONS: Transcardiac release of soluble stimuli for PMN occurs as a result of myocardial ischaemia during CABG. Endothelin-1 may be involved in the plasma-mediated stimulation of neutrophil superoxide anion production.     

Changes in myocardial energy metabolism in elective coronary angioplasty.

STUDY OBJECTIVE--The aim was to investigate the effect of coronary angioplasty on myocardial energy metabolism, and to assure the safety of the procedure in patients with coronary heart disease. DESIGN--Before angioplasty a catheter was introduced into the coronary sinus. Blood samples were taken simultaneously from femoral artery and coronary sinus before balloon inflation, upon balloon deflation, and two minutes later, and arteriovenous differences in myocardial substrates, pH, PCO2, oxygen saturation, and adenosine catabolites were determined. PATIENTS--14 patients with angiographically documented coronary artery disease with lesions in the left coronary artery suitable for elective coronary angioplasty were included in the study. RESULTS--During balloon inflation the positive femoroarterial-coronary sinus difference of lactate turned negative, from 0.21(SEM 0.05) mM to -0.10(0.11)mM, p less than 0.02. At the same time pH and PCO2 differences increased: from 0.04(0.00) U to 0.07(0.01) U, p less than 0.01, and from -1.15(0.10) kPa to -1.41(0.10) kPa, p less than 0.01, respectively. The changes were, however, transient and the arteriovenous differences in these metabolic variables rapidly returned towards preinflation levels after balloon deflation. The femoroarterial-coronary sinus concentration differences in glucose and free fatty acids became positive in coronary angioplasty. The energy state remained good during the procedure as assessed from the negligible net efflux of adenosine and its degradation products. CONCLUSIONS--Elective coronary angioplasty can be performed without any persistent derangements in myocardial metabolism, and may in fact lead to improvement of utilisation of some myocardial substrates. Lactate appears to be a more sensitive indicator of short term ischaemia than adenosine degradation products.     

Coronary venous lipid peroxide concentrations after coronary angioplasty: correlation with biochemical and electrocardiographic evidence of myocardial ischaemia.

BACKGROUND--Raised lipid peroxide concentrations in coronary venous plasma have been reported after coronary angioplasty in humans. This may reflect increased free radical activity after myocardial ischaemia and reperfusion. If so, it may be possible to correlate lipid peroxide concentrations with the degree of myocardial ischaemia produced during angioplasty. METHODS--15 patients (age range 42-70; 12 men) with stable angina pectoris undergoing angioplasty of a proximal left anterior descending coronary artery stenosis were studied. Plasma lipid peroxide and lactate concentrations were measured in sequential blood samples taken from the great cardiac vein before and immediately after one to five serial 60 second balloon inflations. The maximum ST segment shift during each balloon inflation was also measured. RESULTS--Lipid peroxide concentrations in coronary venous plasma were raised from pre-angioplasty values by more than 2 SDs of the relevant measurement error after 27 out of 46 (59%) balloon inflations. Lactate concentrations were raised after 43 out of 46 (93%) balloon inflations. No significant difference was found between the peak percentage change of either lipid peroxide or lactate concentrations after any of the first three serial inflations. The maximum ST segment shift after each of the first three serial inflations was also similar. Coronary venous lactate concentrations after balloon inflation correlated positively with the maximum ST segment shift, but did not correlate with lipid peroxide concentrations. CONCLUSIONS--Raised lipid peroxide concentrations in coronary venous plasma can be detected in humans after balloon angioplasty. There is no positive correlation between lipid peroxide concentrations in coronary venous plasma after angioplasty and the degree of preceding myocardial ischaemia as assessed by either ST segment shift or lactate production. These indices showed that one to three serial 60 second balloon inflations each produce a similar degree of myocardial ischaemia. The origin of the raised lipid peroxide concentrations in coronary venous plasma after angioplasty remains unknown.     

冠状动脉粥样硬化及其介入治疗后血浆尾加压素Ⅱ水平变化的研究

目的　探讨冠状动脉轻度粥样硬化及冠心病血管成形术前后血浆尾加压素Ⅱ (UⅡ )水平的变化。方法　采用放射免疫法测定 17例冠状动脉轻度粥样硬化患者和 10例冠心病患者血浆中UⅡ水平。结果　两组患者静脉血浆UⅡ水平明显低于健康对照 (P <0 .0 0 1) ,冠心病患者股动脉血浆UⅡ水平低于冠状动脉轻度粥样硬化患者(P <0 .0 0 1) ;术后即刻血浆UⅡ水平有升高趋势 ,但无统计学意义 ,术后 2 4h静脉血浆UⅡ水平比术前增高 2 41%(2 2 .75pg/mlvs 6 .6 7pg/ml) (P <0 .0 0 1) ,术后 72h略有下降 ,但仍显著高于术前 (P <0 .0 1)。结论　UⅡ可能参与了冠状动脉粥样硬化的发病过程 ,但其确切的病生理意义以及它是否参与经皮冠状动脉腔内成形术和 /或支架术后再狭窄尚需进一步深入研究。     

Coronary Angioplasty Results in Leukocyte and Platelet Activation With Adhesion Molecule Expression: Evidence of Inflammatory Responses in Coronary Angioplasty

Objectives. This study sought to characterize leukocyte and platelet activation and adhesion molecule expression after coronary angioplasty.Background. Coronary angioplasty can be regarded as a clinical model of postischemic inflammation because this intervention leads to the release of inflammatory mediators as a result of plaque rupture and endothelial injury.Methods. In 13 patients with stable angina (mean [±SEM] age 56.0 ± 2.4 years, range 44 to 79), blood samples were drawn from the aorta and coronary sinus immediately before and immediately and 15 min after coronary angioplasty. Subsequently, leukocyte and platelet functions were determined. Eleven control patients (57.5 ± 2.3 years, range 52 to 78) underwent coronary arteriography.Results. Coronary arteriography and angioplasty showed no difference in number of leukocytes between the coronary sinus and the aorta. However, 15 min after coronary angioplasty, there was an increase in neutrophil CD18 and CD11b, monocyte CD14 and platelet glycoprotein IIb/IIIa expression and a decrease in neutrophil L-selectin expression (189 ± 25%, 163 ± 27%, 158 ± 35%, 141 ± 22% and 31 ± 10%, respectively, p < 0.01). In the control subjects, no change in adhesion molecule expression occurred. Superoxide production and aggregation in ex vivo-stimulated neutrophils collected from the coronary sinus 15 min after coronary angioplasty was significantly decreased compared with that after coronary arteriography (54 ± 12% vs. 106 ± 30% and 58 ± 11% vs. 102 ± 29%, respectively, p < 0.01). The reduced responses to phorbol ester stimulation may be explained by previous in vivo activation of neutrophils during coronary angioplasty.Conclusions. Coronary angioplasty increases neutrophil, monocyte and platelet adhesion molecule expression and induces a significant decrease in ex vivo-stimulated neutrophil superoxide generation and aggregation. These findings suggest that coronary angioplasty triggers cellular activation with an inflammatory response that could contribute to restenosis.(J Am Coll Cardiol 1997;29:1276–83)     

Coronary venous lipid peroxide concentrations after coronary angioplasty: correlation with biochemical and electrocardiographic evidence of myocardial ischaemia

Background—Raised lipid peroxide concentrations in coronary venous plasma have been reported after coronary angioplasty in humans. This may reflect increased free radical activity after myocardial ischaemia and reperfusion. If so, it may be possible to correlate lipid peroxide concentrations with the degree of myocardial ischaemia produced during angioplasty.

Methods—15 patients (age range 42-70; 12 men) with stable angina pectoris undergoing angioplasty of a proximal left anterior descending coronary artery stenosis were studied. Plasma lipid peroxide and lactate concentrations were measured in sequential blood samples taken from the great cardiac vein before and immediately after one to five serial 60 second balloon inflations. The maximum ST segment shift during each balloon inflation was also measured.

Results—Lipid peroxide concentrations in coronary venous plasma were raised from pre-angioplasty values by more than 2 SDs of the relevant measurement error after 27 out of 46 (59%) balloon inflations. Lactate concentrations were raised after 43 out of 46 (93%) balloon inflations. No significant difference was found between the peak percentage change of either lipid peroxide or lactate concentrations after any of the first three serial inflations. The maximum ST segment shift after each of the first three serial inflations was also similar. Coronary venous lactate concentrations after balloon inflation correlated positively with the maximum ST segment shift, but did not correlate with lipid peroxide concentrations.

Conclusions—Raised lipid peroxide concentrations in coronary venous plasma can be detected in humans after balloon angioplasty. There is no positive correlation between lipid peroxide concentrations in coronary venous plasma after angioplasty and the degree of preceding myocardial ischaemia as assessed by either ST segment shift or lactate production. These indices showed that one to three serial 60 second balloon inflations each produce a similar degree of myocardial ischaemia. The origin of the raised lipid peroxide concentrations in coronary venous plasma after angioplasty remains unknown.

     

Neutrophil and platelet activation at balloon-injured coronary artery plaque in patients undergoing angioplasty

Objectives. This study sought to investigate changes in the expression of activation-dependent adhesion receptors on neutrophils and platelets after exposure to the balloon-injured coronary artery plaque.Background. Activation of blood cells at the balloon-injured coronary artery plaque may contribute to abrupt vessel closure and late restenosis after percutaneous transluminal coronary angioplasty.Methods. In 30 patients undergoing elective coronary angioplasty, blood specimens were obtained through the balloon catheter proximal to the plaque before dilation and distal to the plaque after dilation. Simultaneous blood samples obtained through the guiding catheter served as control samples. Total surface expression of the inducible fibrinogen receptor (CD41) and surface expression of the activated fibrinogen receptor (LIBS1) on platelets as well as Mac-1 (CD11b) and L-selectin (CD62L) surface expression on neutrophils were assessed by flow cytometry.Results. After exposure to the dilated coronary artery plaque, surface expression of LIBS1 on platelets increased by 40.5 ± 11.0 mean (±SE) fluorescence (p = 0.001) and that of CD11b on neutrophils increased by 20.1 ± 4.4 mean fluorescence (p = 0.018). Concomitantly, anti-CD62L binding on neutrophils decreased by 6.6 ± 2.4 mean fluorescence (p = 0.022). In contrast, surface expression of the adhesion receptors did not change significantly between the coronary ostium and the prestenotic coronary segment.Conclusions. The results of this study demonstrate neutrophil and platelet activation at the balloon-injured coronary artery plaque. This cellular activation may serve as a target for pharmacologic interventions to improve the outcome of coronary angioplasty.     

The effects of PAF antagonists on arrhythmias and platelets during acute myocardial ischaemia and reperfusion

The aim of the study was to examine a possible role for platelet activating factor (PAF) in experimental myocardial ischaemia and reperfusion. Anaesthetized open-chest greyhounds were subjected to 40 min of coronary artery (LAD) occlusion followed by reperfusion. Blood samples for platelet counting were obtained from a local coronary vein draining the ischaemic region. Pretreatment with PAF antagonists BN52021 (5 mg kg-1 i.v.) or SRI63441 (10 mg kg-1 i.v.), 15 min prior to occlusion reduced the ventricular ectopic count during the ischaemic period from 614 +/- 82 (controls) to 296 +/- 145 (BN52021) and 474 +/- 200 (SRI63441). Both drugs also reduced the incidence of ventricular fibrillation (VF) (during ischaemia and reperfusion) from 90% (controls), to 50% (BN52021) and 43% (SRI63441). Ischaemia was accompanied by a 32 +/- 7% reduction in coronary venous platelets; this was attenuated by both BN52021 (-2 +/- 6%) and SRI63441) (-1 +/- 5%). These results suggest that PAF may contribute to ischaemia and reperfusion-induced arrhythmias by activating platelets.     

Comparison of activation process of platelets and neutrophils after coronary stent implantation versus balloon angioplasty for stable angina pectoris

The pathophysiologic features of stent-induced cellular responses of platelets and leukocytes have not been established. This study was designed to clinically investigate the activation of platelets and neutrophils after coronary stenting and to identify its effects on the long-term results of coronary stents. Forty-eight consecutive patients with left anterior descending coronary artery disease indicating coronary intervention were randomly assigned to either a balloon angioplasty group or a coronary stent group. Flow cytometric analysis demonstrated that the transcardiac gradient (the value of coronary sinus blood minus the value of peripheral blood) of platelet surface expression of CD62P (p < 0.001) and CD63 (p < 0.01) increased immediately after coronary stenting, but increased less significantly immediately after balloon angioplasty (CD62P, p < 0.01; CD63, p < 0.05). These increases were persistently observed after coronary stenting but transiently after balloon angioplasty alone during a 48-hour observation period after the procedures. The gradient for neutrophil surface expression of CD11b increased, and that of CD62 L decreased 48 hours after coronary stenting (CD11b, p < 0.001; CD62 L, p < 0.05), but these changes showed less significance 48 hours after balloon angioplasty alone (CD11b, p < 0.05; CD62 L, p = NS). The gradients 48 hours after the procedures for both CD62P (r = 0.39, p < 0.05) and CD11b (r = 0.44, p < 0.01) were independently correlated with the late loss in the stent group, whereas the correlation was seen only for CD11b (r = 0.38, p < 0.05) in the balloon angioplasty group. Both platelet and neutrophil activation was greater after coronary stenting than after balloon angioplasty. Cellular interactions between platelets and neutrophils may be related to the progression of neointimal proliferation leading to restenosis after coronary stent implantation.     

Percutaneous transluminal angioplasty involving internal mammary artery bypass grafts: a femoral approach

Percutaneous transluminal coronary angioplasty is an effective technique for the treatment of selected patients with ischemic heart disease due to coronary artery stenosis. Successful angioplasty in saphenous vein bypass grafts has been documented, but little experience has been reported using angioplasty in internal mammary artery to coronary artery bypass grafts. Nine of ten patients with stenosis in the internal mammary artery to coronary artery anastomosis or in the coronary vessel distal to the anastomosis site were successfully treated with angioplasty. One patient developed restenosis 1 month after the procedure, and a repeat angioplasty was successful. In one patient, the balloon catheter could not be advanced through the left internal mammary artery to the stenosis site. Technical features of internal mammary artery angioplasty are discussed, including the use of specially designed guiding wires, guiding catheters, and balloon catheters that facilitate angioplasty involving internal mammary arteries from the femoral approach.     

Granulocyte activation after coronary angioplasty in humans

To determine whether percutaneous transluminal coronary angioplasty (PTCA) would lead to neutrophil activation with subsequent discharge of proteolytic enzymes, like elastase, and oxygen free radicals, like superoxide anion, blood samples were taken from the coronary sinus and aorta in 14 patients with stable angina and one-vessel disease who underwent PTCA. Neutrophils were separated by means of the Ficoll-Hypaque system and were stimulated to detect release of elastase and generation of superoxide anion. Plasma levels of elastase were also measured by an immunoenzymatic method. PTCA was successful in all patients. Plasma elastase levels increased significantly at the end of the procedure compared with pre-PTCA values both in the coronary sinus (from 129.2 +/- 16.6 to 286.6 +/- 39.7 micrograms/l, p less than 0.005) and in the aorta (from 117.4 +/- 13.6 to 258.1 +/- 41.3 micrograms/l, p less than 0.005). On the other hand, superoxide anion released in the supernatants after neutrophil stimulation by phorbol-myristate-acetate decreased after PTCA in the coronary sinus (before PTCA, 60.1 +/- 7.1; after PTCA, 40.7 +/- 6.8 nmol 1 x 10(7) granulocytes/ml/15 min, p less than 0.05), whereas a mild but not significant decrease was observed in the aorta (from 58.3 +/- 10.9 to 55.3 +/- 8.6 nmol 1 x 10(7) granulocytes/ml/15 min, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary sinus potassium concentration recorded during coronary angioplasty.

Coronary sinus potassium concentration was measured continuously in two patients undergoing angioplasty of a significant stenosis of the left anterior descending coronary artery. After each coronary occlusion there was a transient rise in coronary sinus plasma potassium concentration caused by washout of potassium which had accumulated in the extracellular fluid during the short period of ischaemia. There were no significant changes in the surface electrocardiogram and the patients experienced no chest pain. Changes in coronary sinus potassium concentration provide a sensitive and early indication of myocardial ischaemia in man.     

Coronary sinus pH during percutaneous transluminal coronary angioplasty: early development of acidosis during myocardial ischaemia in man

Coronary sinus pH was measured continuously in eight patients undergoing angioplasty to the left anterior descending coronary artery. A catheter tip pH sensitive electrode with a response time of less than 300 ms and an output of greater than or equal to 57 mV/pH unit was placed high in the coronary sinus. Recordings were obtained during a total of 24 balloon occlusions of the left anterior descending coronary artery varying in duration from 5 to 45 s. Continuous 12 lead surface electrocardiograms were recorded. During or after balloon inflation of greater than or equal to 12 s (n = 4) there was no change in coronary sinus pH or the electrocardiogram. During balloon inflation of greater than or equal to 15 s (n = 20) coronary sinus pH was unaltered but between 4 and 6 s after balloon deflation coronary sinus pH fell transiently by between 0.010 and 0.120 pH units before returning to the control value within 65 s. Ischaemic changes were seen on the electrocardiogram during 15 balloon occlusions. In individual patients the peak fall in coronary sinus pH was related to the duration of occlusion of the left anterior descending coronary artery. A rise in coronary sinus pH (alkalosis) was never seen. In man acidosis occurs in the myocardium after short periods (greater than or equal to 12 s) of ischaemia. The fall of pH precedes ischaemic changes on the surface electrocardiogram and occurs concurrently with the earliest reported changes in contractile function.     

Hemorheological and oxygen free radical associated alterations during and after percutaneous transluminal coronary angioplasty

Percutaneous transluminal coronary angioplasty (PTCA) is a frequently used method in the treatment of coronary artery disease. Coronary stenosis, endothelial injury, and ischemia-reperfusion caused by the balloon inflation and deflation during this procedure can cause several changes in blood flow. In our study 19 patients (mean age: 58 +/- 9 years) undergoing PTCA were examined. For the laboratory measurements several blood samples were taken from the femoral vein and the coronary sinus before and 30 minutes after PTCA, and from the cubital vein 1, 2, 5 days and 1, 6 months after PTCA. Among hemorheologic parameters hematocrit, plasma fibrinogen level, plasma and whole blood viscosities were measured and corrected blood viscosity value was calculated. To characterize the oxidative stress, samples were analyzed for thiobarbituric acid reactive substances (TBARS) of blood as a marker of lipidperoxidation and changes in the antioxidant system were investigated by measuring the activity of superoxide dismutase, catalase and the concentration of glutathione; superoxide generating capacity of isolated leukocytes and platelet aggregation were examined as markers of cellular activation. Plasma fibrinogen concentration increased markedly during the first and second day after PTCA (p < 0.001), which was accompanied by the elevation of plasma viscosity (p < 0.05). Plasma fibrinogen returned to the baseline at the one-month check-up visit, but there was a significant increase in its concentration by the end of the sixth month follow-up. Apparent whole blood viscosity at 90 s (-1) showed gradually increasing values up to the one- and six-month check-up visits (p < 0.01), which can partially be explained by the elevation of hematocrit. Corrected blood viscosity was significantly elevated on the fifth day already (p < 0.01), and one month later also. Superoxide production of leukocytes showed an increasing tendency (p = 0.05), and blood TBARS was elevated after one day (p < 0.05) and remained higher during the following days. Catalase activity showed significantly increasing values (p < 0.01) during the hospital phase, then at the end of the first month. SOD activity and spontaneous platelet aggregation were higher in the samples from the coronary sinus than in those from the peripheral vein before the procedure; 30 minutes after PTCA increased levels in the peripheral sample were found (p < 0.01). Our findings indicate that PTCA may cause significant changes in the hemorheologic and free radical associated parameters, which can affect the final outcome of this intervention.     

Coronary sinus pH during percutaneous transluminal coronary angioplasty: early development of acidosis during myocardial ischaemia in man.

Coronary sinus pH was measured continuously in eight patients undergoing angioplasty to the left anterior descending coronary artery. A catheter tip pH sensitive electrode with a response time of less than 300 ms and an output of greater than or equal to 57 mV/pH unit was placed high in the coronary sinus. Recordings were obtained during a total of 24 balloon occlusions of the left anterior descending coronary artery varying in duration from 5 to 45 s. Continuous 12 lead surface electrocardiograms were recorded. During or after balloon inflation of greater than or equal to 12 s (n = 4) there was no change in coronary sinus pH or the electrocardiogram. During balloon inflation of greater than or equal to 15 s (n = 20) coronary sinus pH was unaltered but between 4 and 6 s after balloon deflation coronary sinus pH fell transiently by between 0.010 and 0.120 pH units before returning to the control value within 65 s. Ischaemic changes were seen on the electrocardiogram during 15 balloon occlusions. In individual patients the peak fall in coronary sinus pH was related to the duration of occlusion of the left anterior descending coronary artery. A rise in coronary sinus pH (alkalosis) was never seen. In man acidosis occurs in the myocardium after short periods (greater than or equal to 12 s) of ischaemia. The fall of pH precedes ischaemic changes on the surface electrocardiogram and occurs concurrently with the earliest reported changes in contractile function.     

Thrombin activity induced by balloon angioplasty of the coronary artery in Macaca fascicularis (cynomolgus monkey)

In this paper we address the question of whether balloon angioplasty induces thrombin action. In the studies reported here we measured fibrinopeptide A levels in a group of atherosclerotic monkeys undergoing coronary angioplasty. A blood collection catheter was introduced into the inferior vena cava through a femoral vein, and the angioplasty catheter introduced via the femoral artery. Heparin was administered immediately after insertion of the arterial catheter. Serial blood samples were collected for 20 min before angioplasty and for 10 min after angioplasty. Baseline levels of FpA were high, presumably in response to the trauma of introducing the catheters. After heparin administration the FpA concentration declined with a half-time of 1.1 min. In response to balloon inflation there was a clear increase in the concentration of FpA, despite the presence of a therapeutic concentration of heparin. The magnitude of the FpA rise was markedly different between animals, but was evident in the aggregate data after subtraction of background levels of FpA. By integration of the plasma FpA concentration curve, the amount of fibrinogen converted to fibrin in response to angioplasty was calculated to be approximately 0.4 mg/animal. We conclude that angioplasty induces significant activation of the coagulation system.     

Haemodynamic observations during percutaneous transluminal coronary angioplasty in the presence of synchronised diastolic coronary sinus retroperfusion

Animal studies have demonstrated that synchronised coronary sinus retroperfusion with arterial blood can provide effective perfusion of ischaemic myocardium. Preliminary clinical studies have shown that the technique can also be used with safety in human beings, and in the present study its effectiveness was assessed in three patients undergoing repeated coronary artery occlusions during percutaneous transluminal coronary angioplasty. Arterial blood was removed via an 8F catheter positioned in the femoral artery and delivered by a retroperfusion pumping system to a 7F retroperfusion balloon catheter positioned in the anterior cardiac vein. Ischaemia-related indices were monitored both before and during coronary sinus retroperfusion. These indices included high fidelity left ventricular pressure recordings and pressure derived indices (including velocities of isovolumic contraction and relaxation), as well as electrocardiographic changes and symptoms. Analysis of these variables showed that the ischaemic changes induced during coronary artery occlusion were not prevented by this type of coronary sinus retroperfusion. There was no major complication in any of the patients. It may be that adaptation of the technique or the use of alternative end points will establish a benefit, but further modifications of the delivery system are necessary for effective clinical use.     

Haemodynamic observations during percutaneous transluminal coronary angioplasty in the presence of synchronised diastolic coronary sinus retroperfusion.

Animal studies have demonstrated that synchronised coronary sinus retroperfusion with arterial blood can provide effective perfusion of ischaemic myocardium. Preliminary clinical studies have shown that the technique can also be used with safety in human beings, and in the present study its effectiveness was assessed in three patients undergoing repeated coronary artery occlusions during percutaneous transluminal coronary angioplasty. Arterial blood was removed via an 8F catheter positioned in the femoral artery and delivered by a retroperfusion pumping system to a 7F retroperfusion balloon catheter positioned in the anterior cardiac vein. Ischaemia-related indices were monitored both before and during coronary sinus retroperfusion. These indices included high fidelity left ventricular pressure recordings and pressure derived indices (including velocities of isovolumic contraction and relaxation), as well as electrocardiographic changes and symptoms. Analysis of these variables showed that the ischaemic changes induced during coronary artery occlusion were not prevented by this type of coronary sinus retroperfusion. There was no major complication in any of the patients. It may be that adaptation of the technique or the use of alternative end points will establish a benefit, but further modifications of the delivery system are necessary for effective clinical use.     

Effect of percutaneous transluminal coronary angioplasty on arrhythmias complicating angina.

Four patients who had stenosis of a single major coronary artery which was treated by percutaneous transluminal coronary angioplasty are described. Three had exercise induced myocardial ischaemia complicated by ventricular tachycardia, fibrillation, and sinus bradycardia, respectively. Asystole developed in a fourth patient who had spontaneous chest pain. After successful percutaneous transluminal coronary angioplasty these arrhythmias did not recur spontaneously or on treadmill exercise testing. Percutaneous coronary angioplasty can be effective in preventing arrhythmias complicating acute myocardial ischaemia secondary to stenosis of a single major coronary artery.