Detection of coronary artery disease by two-dimensional echocardiography and transesophageal atrial pacing

Two-dimensional echocardiography was performed at rest and during rapid transesophageal atrial pacing in 85 patients undergoing coronary arteriography for evaluation of chest pain. Transesophageal atrial pacing was performed with 10 ms pulses of 6 to 27 mA intensity; the rate was progressively increased up to 150 beats/min. Four patients were excluded: two because atrial capture was not achieved and two because of chest discomfort induced during transesophageal atrial pacing. Of the remaining 81 patients, 56 had significant coronary artery disease (greater than or equal to 75% stenosis of at least one major coronary vessel) and 25 had no significant coronary artery disease; 25 of the 56 patients with coronary artery disease had no wall motion abnormalities at rest. The test was considered positive if wall motion abnormalities were detected during pacing. Wall motion abnormalities occurred in 3 of 25 patients without coronary artery disease (specificity 88%) and in 51 of 56 patients with coronary artery disease (sensitivity 91%). Wall motion abnormalities developed in 20 of the 25 patients with coronary artery disease and normal regional wall motion at rest (sensitivity 80%); sensitivity for one, two and three vessel disease was 85% (17 of 20 patients), 94% (15 of 16 patients) and 95% (19 of 20 patients), respectively. In patients without coronary artery disease, wall motion score was 18 at rest and 17.7 +/- 0.9 during pacing (p = NS). In patients with coronary artery disease, wall motion score decreased from 15.2 +/- 3.6 at rest to 11.6 +/- 4.1 during pacing (p less than 0.001). In patients with coronary artery disease and normal regional wall motion at rest, wall motion score decreased from 18 at rest to 14.4 +/- 3.1 during pacing (p less than 0.001). Thus, two-dimensional echocardiography during transesophageal atrial pacing appears both sensitive and specific in detecting patients with coronary artery disease. This new procedure is a feasible and reliable alternative to exercise two-dimensional echocardiography.     

Comparison of postexercise and transesophageal atrial pacing two-dimensional echocardiography for detection of coronary artery disease

Two-dimensional (2-D) echocardiography during transesophageal atrial pacing (TAP) was recently proposed as an alternative to exercise 2-D echocardiography for the diagnosis of coronary artery disease (CAD). To compare these 2 methods, 78 consecutive patients with good-quality echocardiographic (echo) examinations at rest were studied. Two-dimensional echocardiography was performed immediately after supine bicycle exercise and at peak atrial pacing obtained with transesophageal atrial stimulation. Twenty patients were excluded: 16 because of poor quality of 2-D echo images after exercise and 4 because of inadequate TAP studies (atrial capture not achieved in 2 and intolerance in 2). Of the remaining 58 patients, 39 had significant CAD (at least 75% diameter stenosis of at least 1 major coronary artery) and 19 had no significant CAD. The 2 test responses were considered positive if a wall motion abnormality was detected during pacing or after exercise. Sensitivity and specificity were 82% and 95% after exercise and 90% and 84% during TAP. In patients with significant CAD but without wall motion abnormalities at rest, sensitivity was 75% during pacing and 56% after exercise. In patients with significant CAD, the wall motion score index decreased significantly with both types of stress; during pacing wall motion score index was significantly lower than after exercise. Thus, 2-D echo during TAP appears to be a feasible and reliable alternative to postexercise echo for the detection of CAD.     

Quantitative assessment of transient left ventricular asynergy in coronary artery disease

The purpose of this study was to determine the diagnostic value of quantitative two-dimensional echocardiography during transesophageal atrial pacing in assessing the presence and severity of coronary artery disease. Apical four- and two-chamber views were registered at rest and at different pacing rates. Computerized quantitative evaluation of left ventricle wall motion was performed. On the basis of left ventricle wall motion analysis data of 22 individuals with no coronary pathology, as assessed by angiography and with negative exercise ECG and transesophageal atrial pacing ECG test, nomograms for assessment of wall motion abnormalities and for calculation of asynergy area as a measure of wall motion abnormality extent were obtained. The method revealed new transient wall motion abnormalities during pacing or exacerbation of old ones present at rest in 83 of the 89 patients with angiographically proven coronary artery stenosis greater than or equal to 70% and in 3 of the 32 controls with no changes in their coronary angiograms. Thus, it showed high sensitivity (93%), specificity (91%), predictive value of positive result (96%), predictive value of negative result (83%), and efficiency of the test (93%). These values appeared to be higher than those calculated for transesophageal atrial pacing ECG, recorded simultaneously with echocardiographic images (81, 87, 95, 62, and 83%, respectively) and for exercise ECG test which was performed in 66 coronary patients and in 29 controls (68, 86, 92, 54, and 74%, respectively). The extent of pacing-induced left ventricular regional wall motion abnormalities appeared to be directly correlated to the extent of coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Simultaneous transesophageal atrial pacing and transesophageal two-dimensional echocardiography: a new method of stress echocardiography

The diagnostic use of exercise echocardiography has been widely reported. However, transthoracic exercise echocardiography is inadequate in up to 20% of patients because of poor image quality related to exercise. In an attempt to overcome these limitations, a system was developed in which transesophageal echocardiography is combined with simultaneous transesophageal atrial pacing by means of the same probe. In a prospective study, transesophageal echocardiography was performed before, during and immediately after maximal atrial pacing in 50 patients with suspected coronary artery disease. Results of transesophageal stress echocardiography were considered abnormal when new pacing-induced regional wall motion abnormalities were observed. Correlative routine bicycle exercise testing was carried out in 44 patients. Cardiac catheterization was performed in all patients. The success rate in obtaining high quality diagnostic images was 100% by transesophageal echocardiography. All nine patients without angiographic evidence of coronary artery disease had a normal result on the transesophageal stress echocardiogram (100% specificity). Thirty-eight of 41 patients with coronary artery disease (defined as greater than or equal to 50% luminal diameter narrowing of at least one major vessel) had an abnormal result on the transesophageal stress echocardiogram (93% sensitivity). The sensitivity of the technique for one, two or three vessel disease was 85%, 100% and 100%, respectively, compared with 44%, 50% and 83%, respectively, for bicycle exercise testing; the 12 lead electrocardiogram (ECG) during rapid atrial pacing showed a sensitivity of 25%, 64% and 86%, respectively. Thus, rapid atrial pacing combined with simultaneous transesophageal echocardiography is a highly specific and sensitive technique for the detection of coronary artery disease. Ischemia-induced wall motion abnormalities were detected earlier than observed ECG changes. The technique appears to be particularly suited to patients who are unable to perform an active stress test or those with poor quality transthoracic echocardiograms.     

Stress echocardiography with transesophageal atrial pacing: preliminary report of a new method for detection of ischemic wall motion abnormalities

We performed two-dimensional echocardiography in 19 patients with significant coronary artery disease and in six normal volunteers at rest and during transesophageal atrial pacing. Technically adequate resting echocardiograms were obtained in 18 of the 19 patients and in all six normal volunteers. In two subjects, atrial capture was not possible, and in one subject, discomfort from the pacing at the beginning of the study precluded its completion. In all subjects (n = 21) who completed the protocol satisfactory two-dimensional echocardiograms were obtained during pacing. Wall motion was normal at rest and during atrial pacing in five normal volunteers. New transient wall motion abnormalities developed in 13 of the 16 patients during pacing. Twelve of the 13 patients had significant coronary lesions in the coronary arteries supplying the abnormal wall segment. Only three of the patients developed significant ST segment depression during pacing. We conclude that stress echocardiography with transesophageal atrial pacing is safe and practical and can be used in patients who cannot perform dynamic exercise, this technique can detect ischemic segmental wall motion abnormalities corresponding to the distribution of coronary arterial obstruction, and the technique provides high-quality echocardiographic images during stress and thus may expand the usefulness of resting two-dimensional echocardiography in patients who have ischemic heart disease.     

Simultaneous transesophageal two-dimensional echocardiography and atrial pacing for detecting coronary artery disease.

This study describes a new technique for assessing wall motion abnormalities, combining transesophageal echocardiography (TEE) and transesophageal atrial pacing in 71 patients. Stable capture was reached in 70 patients (99%). In 3 patients (4%) pacing was discontinued prematurely because of discomfort. TEE during pacing was performed in 52 patients with and in 18 patients without coronary artery disease (CAD). In 43 of 52 patients with CAD, regional wall motion abnormalities occurred (sensitivity 83%). No wall motion abnormalities occurred in 17 of 18 patients without CAD (specificity 94%, positive predictive value 98%). Wall motion abnormalities related to another vascular region were observed in 17 of 22 patients with previous myocardial infarction (sensitivity 77%, specificity 100%, positive predictive value 100%). Simultaneous 12-lead electrocardiography during atrial pacing was performed in 57 patients and yielded positive results in 21 of 40 patients with (sensitivity 52%) and in 3 of 17 patients without (specificity 82%, positive predictive value 88%) CAD. Exercise stress testing was performed in 66 patients. Twenty-four of 48 patients with CAD had a positive exercise electrocardiogram (sensitivity 50%); a false-positive exercise electrocardiogram was observed in 3 of 18 patients (specificity 83%, positive predictive value 89%). It is concluded that TEE during transesophageal atrial pacing is a feasible and promising alternative technique for the assessment of CAD, with a higher sensitivity than simultaneous 12-lead and exercise electrocardiography.     

Stress-Doppler echocardiography in the diagnosis of ischemic heart disease in an ambulatory setting]

Coronary arteriography, bicycle ergometry and transesophageal atrial pacing (TAP) in combination with Doppler echocardiography (stress-Doppler echocardiography) were used to evaluate cardialgias in 30 outpatients. Stress-Doppler echocardiography showed a high (94%) sensitivity and a high (86%) specificity to detect coronary heart disease (CHD). There was a high correlation (r = 0.79, p less than 0.001) between the wall motion values obtained by echocardiography during TAP and coronary rating. The left ventricular (LV) diastolic filling (DF) was studied by pulsed wave Doppler echocardiography in the postpacing period. The Doppler-derived parameters of LV DF obtained in that period appeared to be moderately sensitive (75%) and specific (64%) in detecting CHD. In post-pacing ischemia, the "pseudonormalized" LV filling pattern was observed in 5 of 6 patients (sensitivity 80%) having three-vessel disease and major left (or equivalent) coronary stenosis.     

Influence of pacing-induced myocardial ischemia on left atrial regurgitant jet: A transesophageal echocardiographic study

Objectives. We investigated the influence of pacing-induced myocardial ischemia on systolic regurgitant jet in the left atrium, using simultaneous transesophageal echocardiography and transesophageal atrial pacing.Background. In vitro studies have shown that ischemia-induced mitral regurgitation may occur as a result of mitral leaflet malcoaptation or (global) left ventricular dysfunction. However, no transesophageal echocardiographic study has thus far been performed to demonstrate the mechanism and extent of mitral regurgitation during myocardial ischemia in patients.Methods. In 24 patients (mean [±SD] age 57 ± 10 years) with (15 patients) and without (9 control subjects) coronary artery disease, heart rate, blood pressure and systolic regurgitant jet were assessed before and immediately after pacing. Pacing was increased stepwise up to 160 beats/min to provoke wall motion abnormalities while the left ventricular short axis was monitored at the midpapillary muscle level. Other variables obtained before and at peak pacing included left ventricular end-diastolic and end-systolic areas and left ventricular end-diastolic and end-systolic endocardial segmental lengths.Results. Heart rate and blood pressure before and after pacing were not significantly different in control subjects or in patients. At baseline, a jet was present in all but three control subjects. New or increased anterior or posterior wall motion abnormalities were observed during pacing in seven and eight patients, respectively. End-systolic left ventricular areas and segment lengths were significantly reduced in control subjects compared with patients with coronary artery disease at peak pacing (p < 0.05). The increase in systolic regurgitant jet was significantly greater in patients (2.0 ± 1.1 to 3.1 ± 1.8 cm²vs. 0.7 ± 0.7 to 0.9 ± 0.9 cm²[after pacing], p < 0.01). This effect was greater in patients with posterior than with anterior wall motion abnormalities (3.5 ± 1.6 vs. 2.1 ± 1.2 cm²[after pacing], p < 0.05).Conclusions. Quantitative changes in geometry and function of the left ventricle caused by pacing-induced myocardial ischemia augments systolic regurgitant jet size. An increase in the jet during atrial pacing is associated with new or increased wall motion abnormalities, especially of the posterior wall. Pacing-induced anterior wall motion abnormalities appear not to be related directly to an increase in the jet.     

食管心房调搏负荷试验联合平板运动试验对男性冠心病患者的诊断价值

目的 探讨食管心房调搏负荷试验联合平板运动试验对男性冠心病患者的诊断价值.方法 选择拟诊冠心病的男性患者82例,入选病例全部行冠状动脉造影,且造影前或后1个月行食管心房调搏负荷试验和平板运动试验,观察对比直径法确定的冠状动脉狭窄程度和范围与食管心房调搏负荷试验和平板运动试验结果.结果 以冠状动脉造影结果为标准,食管心房调搏负荷试验联合平板运动试验诊断冠心病的敏感度为72.9％,特异度为52.6％,阳性预测价值为90.4％,阴性预测价值为78.7％,食管心房调搏负荷试验及平板运动试验显示冠状动脉狭窄支数越多,ST段压低出现越早、压低程度越大、持续时间越长（P＜0.001）.冠状动脉造影阳性而食管心房调搏负荷试验、平板运动试验阴性者,多为单支病变或病变较轻.结论 简便易行且无创的食管心房调搏负荷试验联合平板运动试验能提高冠心病的诊断率,并可初步估测冠状动脉狭窄程度.     

Feasibility and safety of transesophageal stress echocardiography.

To determine the feasibility and safety of transesophageal stress echocardiography (TSE), 86 patients with chest pain syndrome were studied. The TSE test consists of transesophageal atrial pacing during simultaneous monitoring of left ventricular contractility by the use of transesophageal echocardiography. An octapolar pacing catheter attached to the transesophageal echoscope was used in conjunction with a cardiac stimulator to induce pacing-tachycardia. The optimal pair of electrodes was chosen from 13 possible combinations of the 8-electrode catheter. The pacing rate was increased until greater than or equal to 90% maximal age-predicted heart rate was reached or significant wall motion abnormalities were developed. The test was also stopped if ischemic electrocardiographic changes or progressive chest pain occurred. A successful TSE test was performed on 77 patients (90%). Twenty-one patients (24%) developed Wenckebach AV block during pacing that was resolved by intravenous atropine sulfate in all but one of them. The TSE test could not be completed in nine patients (10%) because we were unable to capture in four patients (5%), there were suboptimal images in three patients (3%), and two patients suffered intolerable epigastric discomfort (2%). Pacing-induced wall motion abnormalities were identified in 53 patients (69%). No serious complications were noted. We conclude that TSE is a feasible nonexercise stress test that can be performed safely in patients with suspected coronary artery disease.     

Interrelation between the extent of atherosclerosis in the thoracic aorta, carotid intima-media thickness and the extent of coronary artery disease

Intima-media thickness (IMT) of the common carotid artery and atherosclerosis of the thoracic aorta have been shown to correlate with coronary artery disease (CAD). This study compares the relation between wall changes in the thoracic aorta and the carotid arteries and the angiographic severity and extent of atherosclerotic lesions in the coronary arteries in patients with verified CAD. Atherosclerotic wall changes in the carotid arteries and the thoracic aorta were measured by B-mode ultrasonography and transesophageal echocardiography (TEE), respectively, in 37 subjects aged 65+/-10 years with angiographically verified CAD. The mean value of the common carotid IMT of the right and left sides was 0.87+/-0.21 mm. All subjects had carotid plaques. TEE detected grades II-IV atherosclerotic plaques in the thoracic aorta in 32 of the 37 (86%) patients. A significant correlation was seen between the extent of coronary artery stenosis and aortic plaques score (r=0.46, p=0.008). Mean carotid IMT was also significantly correlated with coronary artery stenosis extent score (r=0.44, p=0.007). Moreover, a significant correlation was seen between the aortic plaque score and the mean carotid IMT (r=0.39, p=0.02). In conclusion, we found a clear and significant relationship between wall changes in the thoracic aorta, common carotid IMT and the angiographic extent of coronary artery stenosis in patients with severe CAD. These findings indicate a potential of B-mode ultrasonography of the carotid arteries and transesophageal echocardiographic aortic examination in the diagnostic and prognostic evaluation of patients with suspected CAD.     

Dobutamine stress echocardiography: its role in the diagnosis of coronary artery disease.

We have assessed the usefulness of dobutamine infusion for the diagnosis of coronary artery disease by using two-dimensional echocardiography and 12-lead electrocardiogram. Dobutamine was infused at incremental doses (up to a maximum of 40 micrograms kg-1 min-1) in 52 patients with chest pain; all the patients underwent coronary angiography; significant coronary artery disease was quantitatively defined as greater than or equal to 50% diameter stenosis. Thirty-six patients were on betablockers. The test was considered positive when new regional wall motion abnormalities appeared during dobutamine infusion. No significant side effects occurred in any patient during the test. Transient wall motion abnormalities were detected in 20 of 37 patients with coronary artery disease (sensitivity = 54%); ischaemic ST segment changes were present on ECG in nine patients (sensitivity = 24%). Dobutamine stress echocardiography was negative in 12 of 15 patients with coronary artery diameter stenosis less than 50% (specificity = 80%). Exercise electrocardiography (ECG) was performed in 35 of these 52 patients. Maximum heart rate and systolic blood pressure were significantly higher during exercise than during dobutamine stress test (127 +/- 23 vs 99 +/- 24 beats min-1, P less than 0.0001; 179 +/- 25 vs 152 +/- 30 mmHg, P less than 0.0001). The exercise ECG test was positive in 12 of the 26 patients with significant coronary artery disease (sensitivity = 46%), and dobutamine stress echocardiography in 16 (sensitivity = 62%). Dobutamine stress echocardiography test is a safe and feasible diagnostic test for the noninvasive diagnosis of coronary artery disease and can be performed in patients unable to exercise.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dobutamine stress echocardiography: Detection of coronary artery disease in patients with dilated cardiomyopathy

Objectives. This study attempted to determine the safety and accuracy of dobutamine stress echocardiograpby for detection of coronary artery disease in patients with dilated cardiomyopathy.Background. Detection of regional wall motion abnormalities at rest does not reliably distinguish ischemic front nonischemic cardiomyopathy. Previous studies have shown that dobutamine stress echocardiography safely and accurately identifies coronary artery disease in patients without dilated cardiomyopathy.Methods. Seventy patients with dilated cardiomyopathy under-went dobutamine stress echocardiography. Echocardiograms were obtained at baseline and at low (5 to 10 μg/kg body weight per min) and peak doses of dobutamine. Rest and stress left ventricular wall motion scores were derived from analysis of regional wall motion. Fifty-four subjects underwent coronary angiography.Results. Dobutamine infusion was terminated after achievement of the target heart rate or maximal protocol dose in 49 patients (70%), ischemia in 12 (17%), arrhythmia in 4 (6%) and side efects in 5 (7%). No patient had prolonged ischemia or sustained arrhythmia. Of those with angiographic studies, 40 had significant coronary artery disease (≥50% diameter stenosis). Use of the change in global wall motion score index from low to peak dose resulted in a sensitivity of 83% for dobutamine stress echocardiography and a specificity of 71% for detection of coronary artery disease. Sensitivity for detection of triple-,double-and single-vessel disease was 100%, 83% and 69%, respectively.Conclusions. Dobutamine stress echocardiography safely provides diagnostic information in patients with dilated cardiomyopathy. This technique has high sensitivity for multivessel coronary artery disease but only moderate specificity.     

The echo-dobutamine test for the diagnosis of myocardial ischemia. Study on 20 patients with normal kinetics at rest

We have assessed the value of dobutamine stress echocardiography for the diagnosis of myocardial ischemia in 20 consecutive patients referred for chest pain, without a previous myocardial infarction and with a normal left ventricular wall motion at rest. The test was considered positive when wall motion abnormalities appeared during dobutamine infusion (from 5 to a maximum of 40 micrograms/Kg/min). The results were compared to the % diameter stenosis (%DS) quantitatively measured on coronary arteriography. "Significant" coronary artery disease was defined as greater than or equal to 50% DS. No significant side effects occurred in any patients during the test. Transient wall motion abnormalities were detected in 8 of the 12 patients with significant coronary artery disease (sensitivity = 66%) and in 1 of the 8 patients without significant coronary artery disease (specificity = 88%). All the patients with false-negative dobutamine stress echocardiography had distal stenosis or stenosis in a collateral vessel; moreover, all the patients with true-positive dobutamine stress echocardiography had proximal (7 patients) or middle (1 patient) stenosis. The results of this study show that dobutamine stress echocardiography is a safe and feasible test for the noninvasive diagnosis of myocardial ischemia.     

High Quality Stress Echocardiography Using Simultaneous Transesophageal Echocardiographic Imaging and Atrial Pacing

The combination of transesophageal atrial pacing and transesophageal echocardiography (TEE) provides an alternative stress echocardiographic technique capable of assessing pacing-induced wall-motion abnormalities and ischemia-induced mitral regurgitation. The rationale for combining pacing with TEE resulted from experiences with inadequate transthoracic stress studies in up to 15% of the patients and second, from failure of transesophageal atrial pacing with a single lead in another 15% of the patients. Simultaneous TEE and transesophageal atrial pacing was performed in 90 consecutive patients using continuous short-axis monitoring obtained at papillary muscle level. All but one patient had good image quality at rest and during pacing. No complications occurred, in five patients (6%) pacing had to be discontinued prematurely because of discomfort. Early atrio-ventricular Wenckebach block occurred in eight patients (9%). In 83 patients (92%) coronary artery angiography was performed. Sensitivity for assessment of suspected coronary artery disease was 83%, and specificity 94%. Multivessel disease in patients with prior myocardial infarction was assessed with sensitivity of 77%, and specificity of 100%. In 6 of 25 patients (24%) new or increasing mitral regurgitation after induction of wall-motion abnormalities was observed. In conclusion, TEE in conjunction with atrial pacing is feasible, safe, and an alternative echocardiographic stress technique, capable of detecting wall-motion abnormalities and changes in mitral regurgitation. Because of its semi-invasive nature, only patients with a poor transthoracic window are candidates.     

老年冠心病患者冠状动脉病变程度及其侧支循环对左室舒张功能的影响

目的　探讨老年冠心病患者冠状动脉病变程度及侧支循环对左室舒张功能 (LVDF)的影响。方法　 6 8例选择性冠状动脉造影主要分支狭窄≥ 75 %的老年冠心病患者作Leaman冠状动脉记分 ,左室造影测左室射血分数 (LVEF) ,左室壁运动作Cortina记分 ,经胸多谱勒超声血流仪测LVDF ,研究侧支循环对Leaman冠状动脉记分与LVEF、LVDF及Cortina记分间关系的影响。结果　全组Leaman冠状动脉记分与LVEF及Cortina左室壁运动记分无相关 ,与LVDF相关。有侧支循环建立两亚组LVDF差异无显著性意义 ,无侧支循环建立两亚组LVDF差异有显著性意义。结论　老年冠心病患者冠状动脉病变程度与LVDF有关 ,侧支循环的建立对老年冠心病患者的LVDF有保护作用。     

Transoesophageal stress echocardiography for pre-operative detection of patients at risk of intra-operative myocardial ischaemia.

Patients with coronary artery disease have an increased risk of developing intra-operative myocardial ischaemia and peri-operative myocardial infarction. Pre-operative identification of patients at risk of developing peri-operative myocardial ischaemia is often difficult or even impossible due to the inability of the patient to perform an exercise test. For those unable to perform physical exercise a system has recently been described combining transoesophageal echocardiography with simultaneous transoesophageal atrial pacing via the same probe to detect pacing-induced wall motion abnormalities, a sign of coronary artery disease. In a prospective study, 20 patients with clinically suspected coronary artery disease undergoing hip replacement were examined pre-operatively by transoesophageal stress echocardiography. During the subsequent operation the incidence of intra-operative ischaemia was evaluated again in all 20 patients by transoesophageal echocardiography. In eight of the 20 patients (40%) wall motion abnormalities could be induced by transoesophageal stress echocardiography pre-operatively. Intra-operative wall motion abnormalities occurred in six of these eight patients. In two patients with wall motion abnormalities induced by transoesophageal stress echocardiography no abnormalities occurred during surgery. However, in those in whom wall motion abnormalities did occur during operation they occurred in the same left ventricular segment as those initiated by stress echocardiography. None of the patients without pre-operatively inducible wall motion abnormality developed them during surgery. No patient developed a myocardial infarction intra- or post-operatively. Thus, preoperative transoesophageal stress echocardiography is a valuable technique for the detection of patients who may develop ischaemic wall motion abnormalities during surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Exercise echocardiography and single photon emission computed tomography in patients with left anterior descending coronary artery stenosis

To compare the diagnostic value of exercise echocardiography and perfusion single photon emission computed tomography (SPECT) in the detection of the presence and the severity of coronary artery disease, we studied 21 patients with isolated stenosis of different degree of the left anterior descending artery. Both echocardiography and SPECT were performed in conjunction with the same symptom-limited bicycle exercise test. Positivity of the test was based on the presence of exercise-induced wall motion abnormalities and transient perfusion defects, respectively. For both tests, an ischemic score was derived, as index of extent and severity of myocardial ischemia. Coronary arteriography was evaluated by caliper.The agreement between exercise echocardiography and SPECT for the presence of coronary artery disease was 90%; the discordance was due to two patients with positive echocardiography and negative SPECT. A good correlation between ischemic wall motion and perfusion score indices was found (r=0.78, p<0.0001. Moreover, the percent diameter stenosis was well correlated with both ischemic indices (r= 0.75, p<0.0001; r=67, p<0.001, respectively). In patients with a positive test, the mean value of ischemic wall motion score index was higher in patients with a diameter stenosis 70% than in patients with a diameter stenosis <70% (0.59 ± 0.19 vs 0.29 ± 0.12, p < 0.01); a similar trend was found for ischemic perfusion score index (0.51 ± 0.35 vs 0.27± 0.12, ns).The results of this study indicate that in patients with single vessel disease of left anterior descending artery exercise echocardiography and SPECT give the same information on the presence, the extent and the severity of myocardial ischemia.     

Transesophageal echocardiography in combination with atrial stimulation for detection of ischemia-induced disorders of myocardial wall motion]

The diagnostic value of exercise echocardiography has been widely reported. In up to 20% of patients conventional transthoracic exercise echocardiography however is impossible due to impaired image quality related to exercise. In addition some patients will not be able to perform a conventional bicycle exercise test due to joint disease or peripheral vascular disease or a sufficient stress is not possible because of lack of patient motivation. In an attempt to overcome these limitations, a system has been developed which combines transesophageal echocardiography with simultaneous transesophageal atrial pacing via the same probe. Three circular silver pacing electrodes were installed at a distance of 7,9 and 12 cm from the tip of the echoscope. Square wave pulses of 10 ms and an intensity of 7 to 20 mA were delivered. After baseline recording at the patient's spontaneous heart rate, atrial pacing was initiated at a rate of 100 beats/min and increased stepwise every 2 min by 20 beats/min up to 85% of the age-predicted maximal heart rate. Pacing endpoints were designated to be the development of angina pectoris or dyspnea, persisting horizontal or downsloping ST-segment depression (0.2 mV 80 ms after the J-point in the 12-lead ECG) or the development of new segmental wall motion abnormalities. In a group of 50 patients with suspected coronary artery disease, coronary artery disease (luminal narrowing of more than 70% of at least one major vessel) was detected with high sensitivity (greater than 93%) and specificity (greater than 100%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Release of adenosine and lactate from human hearts during atrial pacing in patients with ischemic heart disease

Thirty-eight patients treated by atrial pacing were divided into three groups (Group I, patients with neither coronary stenosis nor anginal pain during pacing; Group II, patients with no coronary stenosis but having anginal pain during pacing; Group III, patients with coronary stenosis). The concentrations of adenosine and lactate were measured in the coronary sinus blood and in the arterial blood before, during, and after atrial pacing. During atrial pacing, significant levels of adenosine were released from the heart of patients in Group III, whereas significant lactate release was observed in Groups II and III. In Group II, the concentration of adenosine in coronary sinus blood appeared to increase during pacing, but not significantly. There was no significant correlation between the release of adenosine and that of lactate. A significant release of adenosine due to atrial pacing may be observed only in patients with coronary artery disease.