Does motion analysis in postexercise gated sestamibi SPECT reflect rest left ventricular motion even in severe coronary artery disease?

PURPOSE: Evidence has suggested that postexercise gated Tc-99m sestamibi SPECT (GSPECT) provides combined information about resting wall motion and exercise perfusion. No data have been published about possible differences in wall motion analysis between postexercise and resting GSPECT. METHODS: Fifty patients underwent postexercise (symptom-limited bicycle stress) and rest GSPECT and cardiac catheterization with contrast ventriculography. In 35 patients, additional rest planar Tc-99m RBC radionuclide ventriculography (RNV) was performed. Four observers independently performed left ventricular ejection fraction (LVEF) calculations and visual analysis of regional wall motion (graded in four stages) for all studies. RESULTS: The LVEF calculations in GSPECT revealed a statistically significant difference between postexercise (45.8 +/- 15.7%) and rest (48.0 +/- 16.1%; P < 0.05) determination. Postrest GSPECT LVEF showed a better correlation with LVEF determination performed with contrast ventriculography and RNV than did postexercise GSPECT LVEF. The reduced postexercise wall motion could be shown in segments with exercise-induced ischemia and in those with normal regional perfusion but not in segments with irreversibly abnormal perfusion. CONCLUSIONS: Postexercise GSPECT provides reliable information regarding global wall motion even in severe coronary artery disease, but regional wall motion is underestimated compared with rest GSPECT, because of an imprecise surface detection algorithm in ischemic wall segments and possibly postexercise stunning in severe coronary artery disease.

ROC analysis of three perfusion display options for ECG-gated perfusion SPECT in severe CAD.

AIM: The simultaneous computation and display of wall motion and perfusion patterns in a single 3D ventricular model would considerably ease the assessment of ECG-gated Tc-99m-sestamibi SPECT, yet the effect on the accuracy of allocating regional perfusion has so far not been validated. METHODS: 3D perfusion mapping (3D Perfusion/Motion Map Software) was compared to the visual assessment of ungated tomographic slices and polar perfusion mapping (Cedars-Sinai PTQ) by correlation analysis and receiver operating characteristics (ROC) analysis at different cut-off levels for coronary stenoses in 50 patients (11 single-, 22 two-, 16 three-vessel disease). Ungated SPECT data were obtained by adding the intervals prior to reconstruction and displaying conventional tomographic slices. All display options were visually assessed in 8 ventricular segments according to a 4-point scoring system and compared to the graded results of coronary angiography. RESULTS: All three display options showed a comparable diagnostic performance for the detection of severe stenoses. The diagnostic gain for the detection of stenoses above 59% was highest for ungated tomographic slices, followed by ungated polar mapping and 3D mapping. Regional assessment revealed a limited performance of 3D mapping in the proximal anterior and distal lateral wall. Polar mapping showed a balanced regional performance. CONCLUSION: 3D Perfusion mapping provides comparable information to conventional display options with the highest diagnostic strength in severe stenoses. Further improvement of the algorithm is needed in the definition of the valve plane.

[Transthoracic recording of pulmonary venous flow for diagnosis of high pulmonary capillary wedge pressure]. / Transthorakale Registrierung des Lungenvenenflusses zur Diagnose eines hohen Pulmonalkapillar-Druckes.

69 patients (46 men, 23 women, age 34 to 78 mean 56 years, all in sinus rhythm) with suspected cardiac insufficiency underwent transthoracic Doppler echocardiography followed by hemodynamic measurement of the pulmonary capillary wedge pressure (= PCP). The echocardiographic measurements included: 1) the peak systolic (S) and diastolic (D) pulmonary venous flow (PVF) velocity (all patients); 2) the E and A peak velocity (62 patients) and 3) the deceleration time (DT, 57 patients) of the mitral flow curve (mean values from 5 to 15 beats). PCP was high (> or = 15 mm Hg) in 27 patients and low (< or = 14 mm Hg) in 42. There were significant correlations between the PCP and all 3 echo parameters: (PCP-S/D: r = -0.69, PCP-E/A: r = 0.66 PCP-DT: r = -0.48, p < 0.05 for all correlations). The sensitivity, specificity, positive and negative predictive accuracy of a pulmonary venous S/D ratio < 1.0 for detecting a high PCP were 82, 83, 76 and 88% respectively, which is similar to the results of previous transesophageal studies. However, slightly reduced S/ID ratios (0.8 to 0.99) were often associated with a normal PCP, and only ratios below 0.8 should be considered as indicative of a high PCP. The mitral flow parameters E/A > or = 1.5 and DT < or = 0.12 s were equally useful in detecting a high PCP: sensitivity, specificity, positive and negative predictive accuracy were 68 and 86, 90 and 80%, 79 and 73%, 84 and 90% respectively. However, E/A ratios between 1.0 and 1.49 were not very useful, representing a high PCP in one third of the cases. There were significant correlations and a high degree of agreement in predicting a high or low PCP between the three Doppler echo parametes, particularly between S/D and E/A ratios. The analysis of pulmonary venous flow by transthoracic echocardiography is a useful method for the non-invasive detection of a high PCP. However, this method no more accurate than the much simpler analysis of mitral flow. The application of the pulmonary venous flow method is indicated when mitral flow cannot be interpreted, for example because of tachycardia, aortic incompetence or an E/A ratio in the ambiguous range (1.0 to 1.49).

Transesophageal echocardiography to assess embolic risk in patients with atrial fibrillation. ELAT Study Group. Embolism in Left Atrial Thrombi.

BACKGROUND: Transesophageal echocardiography visualizes the left atrium and its appendage, thrombi, and spontaneous echocardiographic contrast. OBJECTIVE: To assess the association of transesophageal echocardiographic characteristics with stroke or embolism in atrial fibrillation. DESIGN: Multicenter observational follow-up study. SETTING: Hospitals in Austria and Slovakia. PATIENTS: 409 outpatients with nonrheumatic atrial fibrillation and without recent stroke. INTERVENTION: Patients with thrombi received anticoagulation, and patients without thrombi received aspirin. MEASUREMENTS: Primary events were stroke or embolism. Secondary events were death not caused by stroke or embolism and need for anticoagulation. RESULTS: In the left atrium or left atrial appendage, 10 patients (2.5%) had thrombi and 47 (12%) had spontaneous echocardiographic contrast. The appendage had a mean (+/- SD) length of 44+/-10 mm, a mean width of 23+/-6 mm, and a mean area of 5.8+/-2.5 cm2. Follow-up ranged from 1 to 74 months (mean, 58 months). Fifty patients had stroke or embolism, 53 died of a cause other than stroke or embolism, and 38 required anticoagulation. On univariate analysis, thrombi (risk ratio, 3.9 [95% CI, 1.4 to 10.1]; P = 0.009), length of the left atrial appendage (risk ratio, 1.6 [CI, 1.05 to 2.5]; P = 0.03), and width of the left atrial appendage (risk ratio, 2.4 [CI, 1.2 to 4.81; P = 0.01) were associated with stroke or embolism. Multivariate analysis identified hypertension (risk ratio, 3.6 [CI, 1.8 to 8.4]; P = 0.001), previous stroke (risk ratio, 3.7 [CI, 1.5 to 7.5]; P = 0.002), and age (risk ratio, 1.1 [CI, 1.0 to 1.11; P < 0.001) as risk factors for stroke or embolism and provided evidence of an association between thrombi and stroke or embolism (risk ratio, 2.4 [CI, 0.9 to 6.9]; P = 0.09). CONCLUSIONS: In outpatients with atrial fibrillation and without recent stroke, thrombi of the left atrium or left atrial appendage and length and width of the left atrial appendage were associated with stroke or embolism in univariate analysis. In a multivariate analysis, age, hypertension, and previous stroke were risk factors for stroke or embolism, and thrombi of the left atrium or left atrial appendage were possible risk factors. In these patients, history may be more useful than transesophageal echocardiography for the assessment of embolic risk.

[Pseudo-abnormal venous lung blood flow in trained endurance athletes]. / Pseudo-abnormer Lungenvenenfluss bei trainierten Ausdauersportlern.

Pulmonary venous flow was recorded by transthoracic pulsed Doppler echocardiography in 10 endurance trained male athletes and in 10 age matched sedentary male controls. The ratio of peak systolic (S) to peak diastolic (D) flow velocity was much lower in athletes than in controls (0.8 +/- 0.22 vs. 1.13 +/- 0.37 p < 0.05). 5 out of 10 athletes had values less than 0.82 which was the lowest value in the control group. Athletes also hat significantly higher mitral flow E/A ratios and lower heart rates. Physical fitness caused by endurance training should be acknowledged one of the causes for an abnormally low S/D ratio.

[Embolism in left-atrial thrombi (ELAT Study): are spontaneous echo contrast, thrombi in the left atrium/appendage and size of the left atrial appendage predictors of possible embolisms?]. / Embolien bei linksatrialen Thromben (ELAT-Studie): Sind spontaner Echokontrast, Thromben im linken Vorhof/Herzohr und Grösse des linken Herzohrs Prädiktoren für das Auftreten von Embolien?

Transesophageal echocardiography visualizes the left atrium, the left atrial appendage, thrombi and spontaneous echo contrast within them. The role of these findings as predictors for embolism in atrial fibrillation is unknown. We performed transesophageal echocardiography in 409 non-rheumatic atrial fibrillation outpatients (62 +/- 12 years, 36% female) with no recent (< 1 year) history of embolism. Patients with left atrial/appendage thrombi received oral anticoagulation, those without thrombi Aspirin. The patients were followed up over 2 years. Primary events were stroke, embolism and non stroke/embolism related deaths. Secondary events were initiation of anticoagulation in patients primarily assigned to Aspirin. Left atrial/appendage thrombi were diagnosed in 2.5%. They were associated with diabetes, heart failure and decreased left ventricular fractional shortening (p < 0.05 for each variable). Spontaneous echo contrast was diagnosed in 12%. It was associated with increased age, constant atrial fibrillation, hypertension, heart failure, valvular abnormalities and increased left atrial diameter (p < 0.05 for each variable). Increased left atrial appendage size was associated with constant atrial fibrillation, etiology of atrial fibrillation and valvular abnormalities (p < 0.05 for each variable). Follow-up was 25 +/- 7 months. 29 patients suffered a stroke, 33 further patients died of non stroke/embolism related causes. Secondary events occurred in 19 patients. Neither left atrial/appendage thrombi nor left atrial appendage size were predictors for embolism. Predictors for embolism were increased age (p = 0.003), hypertension (p = 0.01) and increased diastolic blood pressure (p = 0.04). In non-rheumatic atrial fibrillation outpatients with no recent history of embolism, transesophageal echocardiography is of limited value to assess embolic risk. Hypertension and increased diastolic blood pressure have been confirmed in their significance as clinical predictors for embolism.

Interobserver variability in the detection of spontaneous echo contrast, left atrial thrombi, and left atrial appendage thrombi by transoesophageal echocardiography.

OBJECTIVE: To assess the interobserver variability between two observers from different echocardiographic laboratories. DESIGN: Two observers reviewed video recordings blinded to the other's diagnosis. In part I (n = 88), they determined interobserver variability for spontaneous echo contrast, left atrial thrombi, and appendage thrombi. No diagnostic criteria for thrombi were defined. In part II (n = 85), diagnostic criteria for thrombi were defined. RESULTS: Part I: Both observers agreed in diagnosing spontaneous echo contrast in 97%, left atrial thrombi in 90%, left atrial appendage thrombi in 94%. Part II: With predefined criteria no disagreement occurred in diagnosing left atrial thrombi. In the diagnosis of left atrial appendage thrombi both observers agreed in 89%. The mean diameters of the 10 thrombi on which the observers agreed were greater than of the nine appendage thrombi on which they disagreed. CONCLUSIONS: Interobserver variability in the diagnosis of spontaneous echo contrast is low. Defined criteria decrease interobserver variability for left atrial and appendage thrombi, although one third of the thrombi diagnosed by one observer were not confirmed by the other. Interobserver variability is high in the assessment of small structures (< 15 mm) within the left atrial appendage.

[Transesophageal echocardiography in non-rheumatic atrial fibrillation: a moderately sensitive method for assessment of risk of cerebrovascular complications]. / Transösophageale Echokardiographie bei nicht-rheumatischem Vorhofflimmern: eine mässig sensitive Methode zur Abschätzung des Risikos zerebrovaskulärer Komplikationen.

120 consecutive unselected patients with chronic non-rheumatic atrial fibrillation without anticoagulant therapy were examined by transthoracic and transoesophageal echocardiography. Patients with a history of an ischaemic cerebrovascular event (n = 4) had left atrial thrombi, spontaneous contrast or both significantly more often (n = 25, 61%) than patients in the control group (24/79 = 30%). However, when compared with controls, patients with a history of cerebrovascular events were also older, and had hypertension and left ventricular disease (ejection fraction < 45%) more often. Abnormal carotid duplex scans were also very common in this group (71%). Transoesophageal echocardiography is useful for evaluating the risk of cerebrovascular complications in non-rheumatic atrial fibrillation. However, the method is quite insensitive (61%) and therefore insufficient as the sole parameter for deciding the need for anticoagulation. It is likely that cerebrovascular complications in these polymorbid patients are partially caused by other factors than embolism from the left atrium.

Intercoronary collateral flow detected by Doppler colour flow mapping is an additional diagnostic sign in children with anomalous origin of the left coronary artery from the pulmonary artery.

Intercoronary collateral flow within septal collaterals was detected by colour-coded Doppler echocardiography in three children with anomalous origin of the left coronary artery from the pulmonary artery. In each of the three patients angiography confirmed the presence of septal collaterals.

[Acute management of myocardial infarct patients in Austria (cross-sectional study of 8 intensive care units)]. / Akutversorgung von Herzinfarktpatienten in Osterreich (Querschnittsuntersuchung an 8 Intensivstationen).

8 Austrian Intensive Care Units provided data from 6,317 cases (including 1,667 cases with acute myocardial infarction) admitted during 1990 and 1991 for a documentation system offered by the Austrian Heart Foundation. Significant differences were observed between the units concerning admission policies and the use of diagnostic methods. 71% of the AMI cases were first infarctions, 10% were Non-Q-infarcts. The median of the prehospital period varied between 2.5 and 6.5 hours. The evaluation of the admission mode showed that on average 42% of the AMI cases had contact to their G.P. before hospital admission, this figure varying, however, between 24 and 90% in different areas. It seems that this contact takes place to a much lower extent in big cities. On average G.P. contact before hospital admission in AMI resulted in doubling of the duration of the prehospital period. Thrombolytic treatment was applied in 24.7% of AMI cases with a variation between 13.9 and 48.4% in the different centers. It is suggested that regular use of this kind of quality control should offer means for optimizing the acute care of infarct patients on a regional and on a national level.

Value of echocardiography in atrial fibrillation.

In patients with non-valvular atrial fibrillation one must differentiate between those without a clinically suspected embolic event and those who have sustained embolism or stroke of uncertain origin. All of the latter should undergo echocardiography as part of a comprehensive search for a possible source of embolism. A positive finding will enhance the probability that the ischaemic event was indeed caused by a cardiac embolus. It must be kept in mind, especially in stroke patients, that long-term anticoagulation will expose many of them to a far higher risk of haemorrhage [26] due to multimorbidity, propensity to repeated falls and difficulties in compliance than it did to the carefully selected cohorts of the recent warfarin studies. Whenever transthoracic echocardiography (TTE) fails to disclose an unequivocal cardiac source of embolism, transesophageal echocardiography (TEE) should be performed. In persons with atrial fibrillation but no history of systemic embolisation the only rationale for performing echocardiography is to rule out heart disease in clinically suspected lone atrial fibrillation. For the rest of this group TEE remains an investigative tool.

[The effect of concomitant aortic valve insufficiency on the values of Doppler sonographic gradient determination in patients with aortic stenosis]. / Einfluss der begleitenden Aorteninsuffizienz auf das Ergebnis der dopplersonographischen Gradientenbestimmung bei Patienten mit Aortenstenose.

We examined the influence of concomitant significant aortic incompetence (AI) on Doppler-gradient measurements in valvular aortic stenosis (AS) by comparing catheter and Doppler gradients of 51 patients with isolated AS and of 24 patients with additional AI. In patients with additional AI there was a significantly greater overestimation of the peak-to-peak gradient by the maximal instantaneous Doppler gradient (AS + AI: overestimation 31.0 +/- 17.6 mm Hg, AS: overestimation 10.5 +/- 20.2 mm Hg; p less than 0.01) and also by the maximal instantaneous catheter gradient (AS + AI: overestimation 32.8 +/- 11.8 mm Hg, AS: overestimation 20.4 +/- 14.0 mm Hg; p less than 0.01). Comparison of the respective catheter-derived and Doppler-sonographically measured instantaneous and mean gradients showed no differences between the two patient subgroups. Higher instantaneous gradients in patients with additional AI are mainly explained by the lower end-diastolic aortic pressure. However, Doppler-sonographic overestimation of the severity of stenosis in patients with combined AS + AI, due to the sole measurement of the instantaneous gradient in clinical practice, should be of limited importance because in these patients significant AI already sufficiently indicates aortic valve replacement.

Day to day reproducibility of Doppler sonographic measurements in patients with valvular aortic stenosis.

High reproducibility of Doppler gradient measurements is necessary for both the reliable noninvasive assessment of the severity of aortic stenosis and for repeated follow-up examinations in individual patients. We therefore studied day to day reproducibility of Doppler sonographically measured peak pressure drops in 46 patients with valvular aortic stenosis. Clinically stable patients were examined twice within 29 +/- 18.2 days by the same examiner. Peak pressure drop (PPD) and peak flow velocity differed between the two examinations by 8.6 +/- 7.0 (range 0-29) mmHg and by 0.25 +/- 0.18 (range 0-0.7) m/s, respectively. Reproducibility was comparable in patients with excellent, good, and moderate quality examinations, but was lower in the 6 patients with poor quality examination. Variability of PPD, but not of peak flow velocity was higher (p less than 0.05) in patients with severe (PPD greater than 60 mmHg) stenosis. Reproducibility was comparable in patients with or without concomitant aortic incompetence and in patients with normal or reduced left ventricular function. Similar reproducibility was obtained in patients with heart rate changes below or above 10 beats/min between the two examinations. It is concluded that good reproducibility of Doppler measurements in patients with aortic stenosis allows reliable noninvasive assessment of the severity of the stenosis. In follow-up studies of patients with mild to moderate aortic stenosis increases in peak flow velocity in excess of 15% (mean day to day variability +2 SD) are highly indicative of the true progress of the stenosis.

[Doppler echocardiographic determination of aortic valve gradients]. / Doppler-Echokardiographische Bestimmung des Aortenklappengradienten.

Doppler-echocardiography is the most important non invasive method for the assessment of the severity of aortic stenosis. After measuring the maximal transstenotic flow velocity (= Vmax) the maximal pressure drop between left ventricle and aorta (= maximal instantaneous gradient) can bei calculated according to a simple formula. The accurate determination of Vmax may be difficult and time consuming, however, and when interpreting the Doppler-data it is important to realize that there is always a systematic numerical difference between the instantaneous gradient and those gradients which one usually measures at catheterization (peak to peak and mean gradient respectively). In mixed aortic valve disease the aortic insufficiency will distort the relationship between the various gradients still further. Despite these problems Doppler-echocardiography is extraordinarily useful in quantitating aortic stenosis and obviates the need for catheterization in most patients.

Implantation of the Duromedics bileaflet cardiac valve prosthesis in 400 patients.

From September, 1983, to April, 1986, 451 Duromedics bileaflet cardiac valve prostheses were implanted in 400 patients at our institution in Vienna. Aortic valve replacement was done in 190 patients, 157 underwent mitral valve replacement (1 patient also underwent tricuspid valve replacement), 52 underwent double valve replacement, and 1 patient underwent isolated reoperation for tricuspid valve replacement. Concomitant procedures were performed in 86 patients (21.5%). Sixty-one patients (15.2%) had undergone previous cardiac surgery; 32 (8%) had undergone earlier valve replacement. The early mortality rate (within 30 days) was 6.25% (25 patients). Follow-up was done on 337 surviving Austrian citizens; this represents 429 patient-years. The late mortality rate was 2.1% per patient-year (9 patients). We observed paravalvular leak in 3 patients (0.7% per patient-year), thromboembolism in 4 (0.9%), prosthetic valve endocarditis in 5 (1.2%), and anticoagulant-related hemorrhage in 10 (2.3%). Valve failure occurred in 8 patients (1.8%). We conclude, therefore, that good clinical results and a low complication rate can be achieved with this new type of valve.

[Sudden cardiac death during long-term ECG monitoring of a patient with aortic stenosis]. / Plötzlicher Herztod im Langzeit-EKG bei einem Patienten mit Aortenstenose.

Sudden cardiac death was documented on a Holter-monitor ECG in a 71-year-old man with known, but unoperated, calcific aortic stenosis (peak transvalvar gradient of 90 mm Hg). The tracing showed the development of a, presumably stress-induced, sinus tachycardia with broad QRSs and rapid transition to ventricular fibrillation. This rarely documented example of cardiac death in a patient with aortic stenosis during long-term ECG monitoring is of special interest because the patient had neither an inverse therapy effect nor impaired left-ventricular function.

Pseudoidiopathic hypertrophic subaortic stenosis in a patient with cardiac tamponade.

A 53-year-old woman with a large pericardial effusion and tamponade presented with signs of IHSS including a grade 4/6 apical systolic murmur, severe SAM, early systolic aortic valve closure and a small hypercontractile left ventricle but at most borderline left ventricular hypertrophy. Following pericardiocentesis, the clinical and echocardiographic signs of subvalvular obstruction resolved completely. One year later the patient died of bronchial carcinoma and no evidence of hypertrophic cardiomyopathy was found at autopsy. Pericardial tamponade should be added to the list of possible causes of dynamic subvalvular obstruction in a structurally normal heart.

[Doppler sonography quantification of mitral valve stenosis in patients with and without mitral valve insufficiency]. / Doppler-sonographische Quantifizierung der Mitralstenose bei Patienten mit und ohne Mitralinsuffizienz.

Fifty-three patients with mitral stenosis (MS) were examined by two dimensional (2DE) and Doppler echocardiography (Dop). Twenty-nine of them also had mitral insufficiency (MI) as judged by Dop. The mitral valve area (MVA) was calculated from Doppler using the "pressure half time" and was compared with MVA by 2 DE. There was a good correlation between both methods in all 53 patients (r = 0.88; SEE = 0.34 cm2) but also in the subgroups with pure MS (r = 0.86; SEE = 0.29 cm2) and MS + MI respectively (r = 0.90; SEE = 0.38 cm2). The accuracy and the reproducibility of the Doppler method was highly dependent on the severity of the stenosis. In 19 cases with mild MS (MVA by 2 DE greater than 1.5 cm2) the absolute difference between MVA 2 DE and Dop averaged 0.39 cm2. The difference between the maximal and minimal Doppler MVA which reflects the variability of this method averaged 0.65 cm2 in this group. In cases with significant MS (MVA by 2 DE less than or equal to 1.5 cm2) the average difference 2 DE -Dop and Dop max-Dop min was only 0.20 cm2 and 0.27 cm2 respectively. In patients with comparable degrees of stenosis additional MI did not adversely affect the accuracy of the Doppler method. We conclude that Doppler echo allows an accurate quantitation of mitral stenosis even in patients with associated MI.

Two years' experience with the duromedics bileaflet heart valve prosthesis.

The new Duromedics Bileaflet Cardiac Valve prosthesis has a special moving hinge mechanism for its two leaflets to wash the critical articulation area and thus reduce thrombus formation. Between October 1983 and June 1985, we implanted 278 of these prostheses in 254 patients. We did 114 aortic valve replacements, 109 mitral valve replacements, 34 double valve replacements, and two tricuspid valve replacements. Nearly 20% of the patients had had previous cardiac procedures. The hospital mortality was 5.9%. Follow-up was started with 214 surviving Austrian patients, and up to the present time, we have a follow-up period of 1704 patient months. Five patients died late after the operation (3.5 per 100 patient years). We observed 10 valve-related complications in nine patients (7 per 100 patient years). There were three cases of prosthetic endocarditis (2.1 per 100 patient years), two paravalvular leaks, and four bleeding episodes (2.8 per 100 patient years). The mechanical hemolysis was minimal, and the postoperative hemoglobin value averaged 15 g%. The LDH increased from 230 IU to 307 in the aortic valve replacements, 406 in the mitral valve replacements, and 435 in the double valve replacements. Intraoperative pressure gradients and postoperative Doppler echocardiography showed good hemodynamic performance. We conclude that good clinical results and a low complication rate can be achieved with the Duromedics Valve.

[Significance of the stress test for the diagnosis of stenosis of the left main coronary artery. Distinctly different results in relation to the degree of stenosis]. / Die Bedeutung des Belastungsversuches für die Diagnose der Hauptstammstenose der linken Koronararterie. Deutlich unterschiedliche Ergebnisse in Abhängigkeit vom Stenosegrad.

Coronary anatomy and the results of treadmill exercise testing were compared in two partially overlapping groups of patients. In the first part of the study, treadmill tests of 29 patients with significant (greater than or equal to 50%) left main stenosis were compared to those of 40 patients each with proximal 1-, 2-, and 3-vessel disease, respectively. Two distinct subgroups were identified among the patients with greater than or equal to 50% left main stenosis: Of those with greater than or equal to 70% left main stenosis all had a positive (ST decreases greater than or equal to 0.1 mV) stress test, 79% had a markedly positive (ST decreases greater than or equal to 0.2 mV) test and this group had the lowest exercise capacity. In patients with only moderate left main stenosis (50-70%) ST-segment depression was significantly less and occurred significantly later than in patients with severe left main stenosis and 3-vessel disease. Patients with 1-, and 2-vessel disease could be clearly separated from patients with either severe left main stenosis or 3-vessel disease, but not from those with only moderate left main stenosis. In the second part of the study the coronary anatomy of 62 patients with a markedly positive stress test was analysed. In these patients left main stenosis, 3-, 2-, and 1-vessel disease was observed in 10%, 50%, 23% and 16%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)