Evaluation of electron beam tomographic coronary arteriography with three-dimensional reconstruction in healthy subjects

In this study, the authors evaluated the performance characteristics of contrast-enhanced electron-beam tomography (EBT) with three-dimensional reconstruction in defining the coronary artery lumen in healthy subjects. Thirty patients with normal coronary angiograms by selective coronary arteriography (SCA) underwent contrast-enhanced EBT examination. Measured parameters included degree of luminal enhancement, intravascular contrast-to-noise ratio (CNR), and diameter and length of visualized lumen. Ventricular cavity, aortic blood pool, and coronary artery attenuation were found to be significantly different before and after intravenous injection of contrast material (p < 0.001). CNR decreased from proximal to distal segments within each vessel (p < 0.001), with a peak of 11.2 +/- 2.3 occurring in the proximal left anterior descending coronary artery (LAD) to a low of 4.8 +/- 2.0 in the distal left circumflex (LCX). Luminal diameters visualized by EBT had no significant difference with that of SCA (p > 0.05). Therefore, EBT angiography with three-dimensional reconstruction allows for noninvasive coronary arteriography revealing long segments of the major coronary arteries in normal subjects.     

Responses of atherosclerotic human coronary arteries in vivo to the endothelium-dependent vasodilator substance P.

BACKGROUND. The effects of the endothelium-dependent vasodilator substance P (SP) on atherosclerotic human coronary arteries was studied. METHODS AND RESULTS. [125I]-SP binding to luminal cells was shown to be preserved in the atherosclerotic epicardial coronary arteries of four patients. No binding to medial smooth muscle cells was demonstrated. Intracoronary infusions of SP were undertaken in patients with coronary artery disease. SP was infused for 2-minute periods starting at a dose of 2.8 pmol/min rising by doubling increments to 22.4 pmol/min. Analysis of the epicardial coronary artery diameter, using a computerized analysis system (CAAS) of the angiograms, was performed at the end of each infusion. Analysis of seven smooth vessel segments from seven coronary vessels, which were stenosed at more proximal sites, was performed. Significant dose-dependent dilatation was seen (p = 0.04), which was maximal at 5.6 pmol/min SP. No additional dilatation was produced with 2 mg intracoronary isosorbide dinitrate (ISDN). Two of these seven patients showed no response to SP, and only one of these appeared to sustain dilatation with ISDN (2 mg intracoronary). In a second group of six patients with discrete coronary stenoses, analysis at the site of the stenosed segments appeared to reveal dilatation in response to SP in only one instance. One other stenotic segment dilated with isosorbide dinitrate but failed to dilate with SP; the remaining four were fixed. The segment immediately proximal to the stenosis preserved a dose-dependent vasodilator response. CONCLUSIONS. These findings demonstrate that the endothelium-dependent vasodilator substance P can still produce epicardial vasodilatation in vivo in the presence of coronary atherosclerosis.     

The site of plaque rupture in native coronary arteries: a three-vessel intravascular ultrasound analysis

OBJECTIVES: We evaluated the axial location of plaque ruptures in native coronary arteries. BACKGROUND: It is clinically important to understand the potential sites of plaque rupture. METHODS: We performed three-vessel intravascular ultrasound (IVUS) examination in 392 patients; 231 had acute coronary syndrome (ACS) and 161 had stable angina pectoris (SAP). The IVUS detected plaque ruptures in 206 patients: 158 ACS patients and 48 SAP patients. The distance between each coronary plaque rupture segment and the respective coronary ostium was measured with motorized IVUS transducer pullback in all three coronary arteries. RESULTS: There were a total of 273 plaque ruptures in these 206 patients; 143 in the left anterior descending artery (LAD), 40 in the left circumflex artery (LCX), and 90 in the right coronary artery (RCA). There were 67 plaque ruptures in SAP patients and 206 in ACS patients; there were 197 culprit/target lesion plaque ruptures and 76 non-culprit/non-target lesion plaque ruptures. The LAD plaque ruptures were predominantly located between 10 and 40 mm from the LAD ostium (83%, 119 of 143). The LCX plaque ruptures were evenly distributed in the entire LCX tree. Most RCA plaque ruptures were located in segments between 10 and 40 mm (48%, 43 of 90) and in segments >70 mm from the ostium (32%, 29 of 90). CONCLUSIONS: Three-vessel IVUS imaging showed that plaque ruptures occurred mainly in proximal segments of the LAD (83% of LAD plaque rupture), the proximal and distal segments of the RCA (48% and 32% of RCA plaque ruptures, respectively), and the entire LCX.     

Coronary reactivity to ergonovine--possible relationship to accelerated coronary arterial disease in cardiac transplant recipients

Severe coronary artery spasm can occur in orthotopic cardiac transplant recipients. To investigate the possible mechanisms and relevance of coronary spasm to the subsequent development of coronary disease, the response of the coronary arteries to intracoronary ergonovine maleate was studied in 10 patients who had undergone orthotopic cardiac transplantation and were shown to have normal coronary arteries at angiography. Ergonovine in doses of 1, 5 and 10 micrograms was injected into the left coronary artery followed by 2 mg of isosorbide dinitrate. Proximal coronary artery luminal diameters were measured using automated computerized quantitative angiography of the left anterior descending (LAD) and circumflex (LCX) vessels. Five patients (responders) demonstrated a dose response curve to intracoronary ergonovine which was similar to that previously seen in non-transplant patients (mean percentage diameter change +/- SEM, -24.68 +/- 1.93 for LAD, -24.06 +/- 3.91 for LCX). The remaining five patients (non-responders) demonstrated a virtually flat dose response curve significantly different from that of the responders (P = 0.001 for LAD, P = 0.013 for LCX). Angiography after 2 years demonstrated significant coronary disease in four of the five responders to ergonovine. In contrast, the five non-responders to ergonovine continue to have no detectable disease by angiography.     

Responses of angiographically normal human coronary arteries to intracoronary injection of acetylcholine by age and segment. Possible role of early coronary atherosclerosis

We examined the response of left coronary arteries to intracoronary injection of acetylcholine (ACh) 50 micrograms in 74 patients by measuring the diameter changes with a videodensitometric analysis system. Patients with angiographically normal coronary arteries were subdivided into a younger group of 26 patients (age, 9-29 years) and an older group of 23 patients (age, 31-68 years). In the younger group, the diameter at the distal segment of the left anterior descending artery (LAD) and at the proximal, middle, and distal segments of the left circumflex artery (LCx) increased significantly (16.7 +/- 19.3%, p less than 0.01, for LAD and 8.0 +/- 18.8%, p less than 0.05; 11.0 +/- 16.1%, p less than 0.01; and 19.8 +/- 17.5%, p less than 0.01, for LCx segments, respectively) in response to ACh. In the older group, on the other hand, the diameter at the proximal and middle segments of LAD and LCx decreased significantly (-20.8 +/- 16.9%, p less than 0.01; and -17.9 +/- 28.4%, p less than 0.01, for LAD segments and -14.6 +/- 17.4%, p less than 0.01; and -11.3 +/- 21.4%, p less than 0.05, for LCx segments, respectively). The dilator response to ACh in the younger group was significantly greater in the distal segment than in the proximal segment in both LAD and LCx (p less than 0.01 for LAD and p less than 0.05 for LCx). The constrictor response to ACh in the older group was significantly greater in the proximal than the distal segment in both LAD and LCx (p less than 0.05 for LAD and LCx, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Transesophageal Three-Dimensional Echocardiographic Assessment of Normal and Stenosed Coronary Arteries

We describe our preliminary experience in assessing normal and stenosed coronary arteries using transesophageal three-dimensional echocardiography (3-D echo) in 27 adult patients. Multiplane transesophageal two-dimensional images of the coronary arteries (20 left, 3 right, 3 both left and right, and 1 posterior descending) were first acquired in the TomTec computer in 3 degrees sequential increments, from 0 degrees to 180 degrees, and then 3-D reconstruction was performed. The entire left main (LMC, measuring 0.5 to 1.7 cm, mean 1.0 cm) as well as variable lengths of proximal or both proximal and middle segments of the left anterior descending (LAD, measuring 0.2 to 2.5 cm, mean 0.8 cm) and circumflex (LCX, measuring 0.2 to 2.8 cm, mean 0.9 cm) coronary arteries together with some of their branches could be visualized in 3-D in 22 of 23 patients. In the remaining patient, the LMC was absent, and both LAD and LCX could be visualized in 3-D as having separate but adjacent origins from the left sinus of Valsalva (proven by angiography). In two patients, long segments of interventricular and great cardiac veins were also visualized accompanying the LAD and LCX, respectively. The right coronary artery (RCA, measuring 0.7 to 3.0 cm, mean 1.9 cm) was also successfully delineated in 3-D in all six patients in whom an attempt was made to visualize it during echo examination. Using the transgastric approach, a long (1.8 cm) segment of the posterior descending branch (PDA) of RCA was imaged in one patient. In addition, nine significantly stenotic lesions (>50% lumen diameter) were identified by 3-D in eight patients involving LMC (1), proximal LAD (1), mid LAD (1), proximal LCX (2), proximal RCA (3), and mid PDA (1). Eight of these 9 lesions were confirmed by coronary angiography. The remaining lesion (mid PDA) could not be confirmed since the patient did not undergo angiography. Our preliminary study demonstrates the usefulness of transesophageal 3-D echo not only in delineating normal coronary arteries but also diagnosing significant atherosclerotic stenosis in these vessels. (ECHOCARDIOGRAPHY, Volume 13, September 1996)     

Pathological and angiographic regression of coronary atherosclerosis by LDL-apheresis in a patient with familial hypercholesterolemia.

We present the case of a 42-year-old male with familial hypercholesterolemia (FH) who had received long-term low-density lipoprotein (LDL)-apheresis before death occurred, presumably from an arrhythmia. He had been treated with double filtration plasmapheresis (DFPP) for 4 years and selective LDL adsorbent plasmapheresis (LAPP) for 2 years and 7 months. During the period of treatment (6 years and 7 months) he had received a total of 129 sessions of LDL-apheresis. Serum total cholesterol of the patient before the treatment was 638 mg/dl and during the treatment, the time-averaged values ranged from 336 mg/dl to 411 mg/dl for the first 4 years (with DFPP) and from 257 mg/dl to 364 mg/dl for the sequential 2 years and 7 months (with LAPP). Coronary angiograms were analysed for 13 segments of the coronary arteries using a digitized processing system. Analysis documented regression by identifying a reduction in percent stenosis from 34% to 20% in the proximal left circumflex artery (LCX), from 78% to 61% in the proximal right coronary artery (RCA), and from 92% to 72% in the middle RCA. In the other 10 segments analysed no significant regression and no progression were observed. The autopsy findings of the step-wise serial sections of the native coronary arteries did not record the formation of new and/or typical atheroma. In addition, a thickened intima, and an eccentric thickened wall lesion rich in collagen fiber were observed, although an accumulation of foam cells in the thickened wall lesions was found in some segments. This observation suggested scarring of the atheromatous plaque. We confirmed that LDL-apheresis performed over a period of 6 years and 7 months induced angiographic regression of coronary atherosclerosis in the patient with FH, and found that most of the atherosclerotic lesions were changed pathologically into sclerotic lesions rich in collagen fiber.     

The diameter of coronary artery is enlarged in patients with dilated cardiomyopathy

Background Dilated cardiomyopathy(DCM) is a primary cardiomyopathy characterized by the enlargement of left ventricle or biventricular and left ventricular systolic dysfunction, without any obvious stenosis of coronary arteries. However, it remains unclear that whether the diameter of coronary artery is different from those of normal population, because few studies directly assessed the diameter of the coronary artery in patients with DCM. The study aimed to evaluate the diameter of coronary arteries in DCM patients and its influence on prognosis for DCM patients. Methods Fifty-seven DCM patients and fifty-nine patients presenting with atypical chest pain and normal coronary angiography were enrolled in the study. A coronary angiography image analysis system was used to measure the diameters at 5 mm from the opening of the left main coronary artery(LM), left anterior descending(LAD) and left circumflex coronary(LCX) arteries, and the right coronary artery(RCA) of both groups. Follow-up study through telephone over a period of 2 years was performed. Spearman rank correlation and logistic regression were used to evaluate the correlations of the diameter of coronary arteries with the risk of nonfatal heart failure event. Results Diameters of the LM, LAD, LCX, and RCA in DCM group were significantly larger than those of the control group(P 0.001). During a follow-up of 2 years, the nonfatal heart failure event occurred in 9 patients of DCM group, but not in control group. Spearman rank correlation analysis showed diameters of the LM, LAD, and LCX were correlated with the risk of nonfatal heart failure event, respectively(P 0.05). While the diameter of RCA showed no correlation with the risk of nonfatal heart failure event(P =0.583). Whereas logistic regression analysis showed there were no correlation between diameters of the LM,LAD, LCX, and RCA and the risk of nonfatal heart failure event(P 0.05). Conclusions The coronary arteries of DCM patients show a larger diameter without any obvious stenosis, which may not correlate with the risk of heart failure event.     

A rare coronary anatomy comprising dual (Type IV) left anterior descending arteries and an anomalous left circumflex artery from the right coronary artery

We present the case of a rare coronary anomaly in a 64-year-old male who presented with exertional angina. The right coronary artery (RCA) was dominant, giving origin proximally to an anomalous left circumflex (LCX) artery and a left anterior descending (LAD) artery which supplied the conventional mid and distal LAD territory. The left main artery (LM) arose from the left coronary sinus and branched into a large first septal and an intermediate artery. There was associated non-critical atherosclerotic disease. We report this because of the rare division of the LAD area of supply by arteries from both coronary sinuses (dual LAD) with an anomalous LCX also arising from the proximal RCA. The clinical implications are discussed.     

Coronary angioscopy: a monorail angioscope with movable guide wire

A new angioscope was devised for easier visualization of the coronary artery. In its tip, the angioscope (Olympus) with an outer diameter of 0.8 mm had a metal lumen, through which a 0.014-in steerable guide wire passed. Using a 8F guiding catheter and a guide wire, it was introduced into the distal coronary artery. With injection of warmed saline through the guiding catheter, the coronary segments were visualized. In the attempted 70 vessels (32 left anterior descending [LAD], 10 right coronary [RCA], 28 left circumflex [LCX]) from 48 patients, 60 vessels (86%) were successfully examined. Twenty-two patients who underwent attempted examination of both LAD and LCX; both coronary arteries were visualized in 19 patients (86%). In the proximal site of the lesion, 40 patients have the diagonal branch or the obtuse marginal branch. In 34 patients (85%) the angioscope was inserted beyond these branches. In 12 very tortuous vessels, eight vessels (67%) were examined. In conclusion, the new monorail coronary angioscope with movable guide wire is useful to examine the stenotic lesions of the coronary artery.     

Successful transradial intervention for two lesions with dual anomalous origins of coronary arteries

A 76-year-old male was admitted to our hospital for effort angina pectoris. His coronary computed tomography and coronary angiography revealed anomalous origins of the left anterior descending artery (LAD) from the proximal right coronary artery (RCA) and the left circumflex coronary artery (LCX) from the separate ostium in the right coronary cusp. Severe stenoses were present in the proximal segment of the LAD and in the middle segment of the LCX, which were successfully treated by 5 French (Fr) transradial approach intervention. Congenital coronary anomalies are relatively rare, with a prevalence of approximately 1.3% in a large-series study undergoing coronary angiography. Such anomalies occur in several anatomical arrangements, which have been classified in a number of research reports. Here we describe previously unreported dual anomalous origins of coronary arteries associated with significant atherosclerotic lesions, which were successfully treated by 5 Fr transradial approach intervention.     

Evidence of partially preserved endothelial dilator function in diseased coronary arteries

OBJECTIVE—To examine the effects of substance P (endothelium dependent vasodilator) and glyceryl trinitrate (endothelium independent vasodilator) on epicardial coronary arteries in patients with normal coronary angiograms and patients with coronary artery disease.
DESIGN—Intracoronary infusions of normal saline, the receptor mediated nitric oxide stimulant substance P (5.6 and 27.8 pmol/min each for five minutes), and glyceryl trinitrate (250 µg bolus) were given in 24 patients with coronary artery disease and stable angina, and in nine patients with normal angiograms. The diameter of proximal and distal coronary segments was measured by computerised quantitative angiography
RESULTS—Proximal segments of patients with coronary artery disease dilated less than those of patients with normal angiograms in response to 27.8 pmol/min substance P (mean (SEM): 7.9 (1.3)% v 15 (2.3)% respectively, p < 0.01). The proximal segments of diseased arteries also dilated less than those of "normal" arteries in response to glyceryl trinitrate (10.2 (1.6)% v 18.4 (2.9)%, respectively, p < 0.01). The responses of distal segments to substance P and glyceryl trinitrate were similar in the two patient groups. There were correlations (all p < 0.001) between the coronary diameter after substance P and after glyceryl trinitrate in normal proximal segments (r = 0.94) and normal distal segments (r = 0.64), in diseased proximal segments (r = 0.95) and diseased distal segments (r = 0.89), and for coronary stenoses (r = 0.93).
CONCLUSIONS—Proximal segments of patients with coronary disease dilated less than the proximal segments of "normal" patients in response to substance P and glyceryl trinitrate. The response to substance P is substantial and closely correlated with the response to glyceryl trinitrate in both "normal" patients and those with coronary disease. This suggests that although the proximal segments of diseased coronary arteries have a reduced capacity to dilate in response to direct stimulation of smooth muscle cell relaxation, they retain much of their endothelium dependent vasodilator function.


Keywords: endothelium; nitric oxide; coronary artery disease; glyceryl trinitrate     

Correspondence between left ventricular 17 myocardial segments and coronary arteries.

AIMS: The last guidelines recommend a standardized 17-segment model for tomographic imaging of the left ventricle. The aim of this study is to analyse the correspondence of the 17 left ventricular segments with each coronary artery by myocardial perfusion SPECT studies. METHODS AND RESULTS: Fifty patients selected for percutaneous revascularization of one coronary artery [24 left anterior descending (LAD), 15 right coronary artery (RCA), and 11 left circumflex (LCX)] were included. The (99m)Tc-labelled compound was injected immediately after the inflation of the balloon during percutaneous coronary angioplasty. At least 90 s of complete occlusion time was required. Maximal contour of regions of hypoperfusion corresponding to each coronary artery occlusion were delineated over the polar map of 17 segments. Nine segments corresponded to only one coronary artery: eight to LAD (basal anterior, basal anteroseptal, mid-anterior, mid-anteroseptal, apical anterior, apical septal, apical lateral, and apex) and one to LCX (basal anterolateral). Basal inferoseptal, mid-inferoseptal, and apical inferior segments could correspond to LAD or RCA. Basal inferior, basal inferolateral, mid-inferior, and mid-inferolateral segments could correspond to RCA or LCX, whereas the mid-anterolateral segment could correspond to LAD or LCX. CONCLUSION: The most specific segments (anterior, anteroseptal, and all apical segments except the infero-apical) correspond to LAD but no segment can be exclusively attributed to the RCA. Inferoseptal segments can be attributed to LAD or RCA, inferior and inferolateral segments to RCA or LCX, and mid-anterolateral segment to LAD or LCX.     

Coronary to pulmonary artery fistulas: an incidental finding with challenging therapeutic options

We report the incidental finding of 2 coronary to pulmonary artery fistulas observed at coronary angiography performed in a 48-year-old man presenting with acute inferior ST-elevation myocardial infarction (STEMI). Coronary angiography revealed an acute thrombotic occlusion of the mid segment of the right coronary artery (RCA), which was treated with thromboaspiration and bare-metal stenting. Significant stenoses of the left anterior descending (LAD) and left circumflex (LCX) arteries were also observed during angiography, as well as the presence of 2 large coronary to pulmonary artery fistulas, one originating from the proximal LAD and the other from the ostial RCA. The clinical evolution was uneventful and the patient underwent successful coronary bypass grafting of the LAD and LCX lesions associated with ligation of the coronary artery fistulas 6 weeks later. The fact that 2 large coronary to pulmonary artery fistulas were observed during an acute coronary syndrome in a previously asymptomatic patient with extensive coronary artery disease is of particular interest, because it allowed early surgical correction of this rare inborn coronary anomaly before the development of late and irreversible left ventricular dysfunction.     

Congenital absence of left circumflex coronary artery presented with vasospastic angina and myocardial bridge in single left coronary artery

Congenital absence of left circumflex coronary artery (LCX) is a very rare congenital anomaly of the coronary circulation, and few cases have been reported in the literature. We report a case of a 48-year-old male who had congenital absence of LCX presented with vasospastic angina. Routine coronary angiography showed congenital absence of the LCX, typical myocardial bridge in the mid left anterior descending coronary artery (LAD) and super-dominant right coronary artery (RCA). The dominant LAD showed a spastic appearance at the baseline coronary angiography and significant spasm was induced by incremental intracoronary acetylcholine (ACh) provocation test at mid LAD where the myocardial bridge site was observed and was extended to the distal LAD. Typical anginal chest pain was documented during the Ach provocation test and the patient was stabilized with conventional anti-anginal medication. Precise morphological and functional evaluation of the anomalous coronary artery is important for selecting the best treatment modality and better prognosis.     

冠状动脉管径与分叉角度的CT冠状动脉成像研究

目的 在冠状动脉CT图像上分析测量成人血管直径与血管分叉的生体信息,进一步加深对冠状动脉应用解剖的认识.方法 选择64排螺旋CT冠状动脉扫描图像质量优秀、血管完全正常的526例成人为观察对象,测量左主干及前降支、回旋支、右冠状动脉自开口至直径2 mm处每间隔1 cm处的管腔直径,计算管腔渐变率;测量大的对角支、钝缘支、锐缘支、后降支、左室后支(直径大于2 mm)开口直径,与同平面交角的主支血管直径和其上方1 cm处主干血管的直径以及分叉的角度.结果 前降支管径从开口的平均3.92 mm经过13 cm后移行为2.10 mm,呈逐渐变细的趋势,所有管腔的平均变化率为7.7％(男性7.0％,女性8.4％),管腔在距开口3 ～5 cm处变化率最大,达8.0％～10.0％;回旋支管径从开口平均的3.57 mm经过13 cm后移行为2.10 mm,呈逐渐变细的趋势,所有管腔的平均变化率为9.7％(男性9.6％,女性9.7％),开口至近端3 cm处管径变化率约3.0％,其后各点变化在8.3％～10.7％;右冠状动脉管径从开口平均的3.97 mm经过18 cm后移行为2.15 mm,呈逐渐变细的趋势,所有管腔的平均变化率为5.1％(男性4.9％,女性5.3％),开口至10 cm处管径变化率＜4.0％,其后变化率加大,在6.1％～15.2％之间.前降支与对角支、回旋支与钝缘支、右冠状动脉与后降支(左室后支)、右冠状动脉与锐缘支的夹角分别约为50°、55°、66°和76°.结论 64排螺旋CT冠状动脉成像可在生体上测量冠状动脉,获取三支主干血管的渐变率与最大渐变部位以及冠状动脉血管分叉的数据,进一步加深对冠状动脉应用解剖的认识.     

Effect of atrial natriuretic factor on coronary vascular tone

To test whether atrial natriuretic factor (ANF) may be involved in the modulation of coronary vasomotor tone, ANF was injected into angiographically normal left coronary arteries. Measurement of epicardial diameters of the circumflex (Cx) and left anterior descending artery (LAD) were made from biplane angiograms by an automatic contour-detection system. Bolus injection of ANF (0.07 micrograms/kg, diluted in 1 ml 0.9% NaCl, n = 7) increased diameter of proximal segments of LAD (11 +/- 4%) and Cx (10 +/- 4%) (p less than 0.02 each vs control) without altering heart rate and mean arterial pressure (MAP). Intracoronary nitroglycerin (NTG, 0.3 mg) increased diameters of identical LAD and Cx segments by 18 +/- 3% and 20 +/- 4%. Intracoronary ANF infusion (0.02 micrograms/kg/min over 5 min, followed by 0.1 micrograms/kg/min, n = 10) exerted dose-dependent increases in diameters of LAD and Cx (low dose: + 5 +/- 2%, p less than 0.05 vs control; high dose: + 13 +/- 3%, p less than 0.01 vs control). ANF-infusion increased arterial plasma ANF levels from 280 +/- 80 pg/ml during control to 894 +/- 82 pg/ml (low dose; + 614 pg/ml vs control) and to 2290 +/- 228 pg/ml (high dose). Severe ischemia in four patients undergoing angioplasty exerted substantial increase in arterial ANF levels (160 +/- 60 to 608 +/- 111 pg/ml; + 448 pg/ml vs control), similar to the increase elicited by low dose ANF infusion in man.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary flow velocity dynamics in normal and diseased arteries

Distal coronary flow velocity measurements were previously limited to open heart or experimental procedures. Unlike previous Doppler catheter techniques, a Doppler angioplasty flow wire permits flow velocity measurements in both the proximal and distal segments of normal and diseased coronary arteries. In order to determine the potential clinical application of the Doppler flow wire, we performed baseline and hyperemia flow velocity measurements in proximal and distal segments of 20 angiographically normal arteries (right coronary = 8; left circumflex = 7; left anterior descending = 5) and 29 significantly stenosed arteries. All 3 normal coronary arteries had a diastolic-predominant pattern in both proximal and distal segments; the right coronary artery showed significantly toss diastolic predominance. The coronary vasodilator reserve was similar in all three normal coronary arteries, and in the proximal and distal arterial segments. Abnormal arteries had significantly tower coronary vasodilator reserve (normal vs abnormal, 2.3 ± 0.8/ 1.6 ± 0.7; p < 0.02). Normal arteries had preservation of velocity parameters in the distal segments; abnormal arteries had a significant decrease in distal velocity parameters. The proximal-to-distal velocity ratio was thus significantly higher in abnormal arteries (2.4 ± 0.7 vs 1.1 ± 0.2; p < 0.001). The coronary vasodilator reserve in proximal and distal arteries—in addition to the proximal to distal velocity ratio—may provide functional and hemodynamic data complementary to coronary angiography in the assessment of coronary artery stenosis.     

数字电影计帧法对冠状动脉狭窄程度的功能性评价

目的:通过对经皮冠状动脉腔内成形术(PTCA)前后病变血管的电影充盈帧数的计测,探讨数字电影计帧法对冠状动脉狭窄程度的功能性评价.方法:选择冠状动脉前降支单支病变择期PTCA患者(PTCA组)68例,同期冠状动脉造影正常者(对照组)38例.用德国西门子Angiostar plus血管造影机,以30帧/秒进行数字电影图像采集.计测PTCA前后冠状动脉左前降支和回旋支的电影帧数,并计算前降支与回旋支电影帧数比值(LAD/LCX).结果:病变血管的电影帧数PTCA后显著低于PTCA前,有极显著性差异(P＜0.01),而回旋支的电影帧数PTCA前后无显著变化.PTCA前PTCA组LAD的电影帧数显著高于对照组,有极显著性差异(P＜0.01),PTCA后两者对比无显著差异.PTCA前的电影帧数LAD/LCX显著高于PTCA后,有极显著性差异(P＜0.01).结论:左前降支的电影帧数及LAD/LCX随病变程度的加重而增加.计帧法能够更准确地反映狭窄局部的功能状况.     

Does Passive Smoking Impair Endothelium-Dependent Coronary Artery Dilation in Women?

Objectives. This study sought to examine whether passive smoking is associated with endothelial dysfunction in the coronary arteries.Background. Long-term exposure to cigarette smoking has been reported to suppress endothelium-dependent arterial dilation in humans. Endothelial dysfunction is an early feature of atherogenesis, and the impairment of acetylcholine (ACh)-induced coronary artery dilation indicates coronary endothelial dysfunction.Methods. We studied 38 women (40 to 60 years old) who had no known risk factors for coronary artery disease other than tobacco smoking: 11 nonsmokers who had never smoked and had never been regularly exposed to environmental tobacco smoke; 19 passive smokers with self-reported histories of exposure to environmental tobacco smoke of ≥1 h/day for ≥10 years; and 8 active smokers. We examined the response of the epicardial coronary artery diameters (proximal and distal segments of the left anterior descending [LAD] and left circumflex [LCx] coronary arteries) to the intracoronary injection of ACh into the left coronary artery by means of quantitative coronary angiography.Results. ACh significantly dilated the distal segment in nonsmokers (percent change from baseline diameter: LAD 13.7 ± 3.4%, p < 0.05; LCx 18.8 ± 2.9%, p < 0.01) but not the proximal segment (LAD 7.4 ± 3.5%; LCx 3.1 ± 5.0%). ACh significantly constricted all segments of the left coronary artery in passive smokers (LAD: proximal −20.3 ± 3.7%, p < 0.05; distal −22.3 ± 4.1%, p < 0.01; LCx: proximal −20.8 ± 3.1%, p < 0.05; distal −17.3 ± 2.9%, p < 0.01) and active smokers (LAD: proximal −14.8 ± 3.4%, p < 0.05; distal −27.2 ± 6.0%, p < 0.01; LCx: proximal −14.5 ± 6.6%, p < 0.05; distal −22.4 ± 4.0%, p < 0.01). Thus, ACh constricted most coronary arteries in both passive and active smokers and dilated the coronary arteries in nonsmokers.Conclusions. Impairment of ACh-induced coronary artery dilation, indicating coronary endothelial dysfunction, may occur diffusely in passive smokers as well as in active smokers.