[Non-invasive assessment of coronary flow reserve - valuable functional information in cardiac workflow]. / Erfassung der koronaren Flussreserve mit hochauflösender Echokardiographie - Klinischer Stellenwert in der kardiologischen Diagnostik.

Coronary flow reserve can be determined echocardiographically in the LAD in about 90 % and in the RCA in more than 80 % of patients respectively by the use of modern high-resolution ultrasound equipment. For this purpose either high frequency fundamental imaging or echo-contrast enhanced harmonic Doppler technology is used. The main advantage of the method lies in its noninvasiveness and the lack of radiation exposure. In combination with coronary morphologic findings obtained from heart catheterization, CFR is helpful in the planning of further invasive procedures for coronary artery disease and in the estimation of the prognosis of such procedures. The functional status after PTCA of LAD/RCA or mammary bypass surgery can be evaluated during follow-up monitoring. Alteration in the coronary microcirculation can also be discovered in a non-invasive way, improvement of microcirculatory disorders by adequate therapy can be assessed by serial measurements of CFR.

[Non-invasive assessment of coronary flow reserve--valuable functional information in cardiac workflow]. / Nicht invasive Bestimmung der koronaren Flussreserve mittels Echokardiographie. Klinische Wertigkeit in der kardiologischen Diagnostik.

Coronary flow reserve (CFR) can be determined echocardiographically in the LAD in about 90% and in the RCA in more than 70% of patients, respectively, by the use of modern high-resolution ultrasound equipment. For this purpose either high frequency fundamental imaging or echo-contrast enhanced harmonic Doppler technology is used. The main advantage of the method lies in its noninvasiveness and the lack of radiation exposure. In combination with coronary morphologic findings obtained from heart catheterization, CFR is helpful in the planning of further invasive procedures for coronary artery disease and in the estimation of the prognosis of such procedures. The functional status after PTCA of LAD/RCA or mammary bypass surgery can be evaluated during follow-up monitoring. Alteration in the coronary microcirculation can also be discovered in a non-invasive manner; improvement of microcirculatory disorders by adequate therapy can be assessed by serial measurements of CFR

Refinements in stress echocardiographic techniques improve inter-institutional agreement in interpretation of dobutamine stress echocardiograms.

AIMS: To determine the degree of inter-institutional agreement in the assessment of dobutamine stress echocardiograms using modern stress echocardiographic technology in combination with standardized data acquisition and assessment criteria. METHOD AND RESULTS: Among six experienced institutions, 150 dobutamine stress echocardiograms (dobutamine up to 40 microg x kg(-1) min(-1) and atropine up to 1 mg) were performed on patients with suspected coronary artery disease using fundamental and harmonic imaging following a consistent digital acquisition protocol. Each dobutamine stress echocardiogram was assessed at every institution regarding endocardial visibility and left ventricular wall motion without knowledge of any other data using standardized reading criteria. No patients were excluded due to poor image quality or inadequate stress level. Coronary angiography was performed within 4 weeks. Coronary angiography demonstrated significant coronary artery disease (> or = 50% diameter stenosis) in 87 patients. Using harmonic imaging an average of 5.2+/-0.9 institutions agreed on dobutamine stress echocardiogram results as being normal or abnormal (mean kappa 0.55; 95% CI 0.50-0.60). Agreement was higher in patients with no (equal assessment of dobutamine stress echocardiogram results by 5.5+/-0.8 institutions) or three-vessel coronary artery disease (5.4+/- 0.8 institutions) and lower in one- or two- vessel disease (5.0+/-0.9 and 5.2+/-1.0 institutions, respectively; P=0.041). Disagreement on test results was greater in only minor wall motion abnormalities. Agreement on dobutamine stress echocardiogram results was lower using fundamental imaging (mean kappa 0.49; 95% CI 0.44-0.54; P<0.01 vs harmonic imaging). CONCLUSION: Modern echocardiographic technology in combination with standardized digital image processing and uniform reading criteria results in a higher inter-institutional agreement in the interpretation of dobutamine stress echocardiogram compared to historic reports.

[Echocardiographic measurements of coronary flow reserves in the left anterior descending artery allows detection of significant stenosis]. / Die echokardiographische Bestimmung der koronaren Flussreserve im Ramus interventrikularis anterior ermöglicht die Erkennung signifikanter Stenosen.

BACKGROUND AND OBJECTIVE: CFR has proven to be useful in the selection of patients undergoing invasive treatment of coronary artery disease and in estimating their prognosis. However, CFR could only be determined in everyday practice invasively during catheterization procedures. Recent development of high-resolution transthoracic color Doppler echocardiography (TTCD) allows transthoracic visualization of distal LAD and supra-apical intra-myocardial perforator branches, and non-invasive measurement of CFR. The feasibility of non-invasive assessment of coronary flow reserve (CFR) in the left anterior descending artery (LAD) using echo-enhanced high resolution TTCD was investigated. The results were compared with the degree of coronary diameter-stenosis obtained during cardiac catheterization. CFR was determined by measuring to ratio of pulsed wave Doppler time velocity integral during adenosine-induced hyperemia (140 micrograms/kg/min i.v.) to baseline value. If Doppler signal of LAD flow was insufficiently at basal condition, an echo enhancer (Levovist) was used. PATIENTS AND METHODS: 70 patients were examined by TTCD (7 MHz B-Mode, 5 MHz color Doppler, 3.5 MHz PW-Doppler) after coronary angiography had been performed. Gr I consisted of 14 patients without heart disease, Gr II of 26 patients with 40-75% isolated LAD diameter-stenosis, and Gr III of 30 patients with > 75% LAD diameter-stenosis. RESULTS: CFR could be quantified in 56/70 patients (80%), in 42/70 patients without echo enhancer, and in 14/28 patients with an echo-enhancing agent. CFR in Gr I was 3.84 +/- 0.57, in Gr II 2.31 +/- 0.20 (vs Gr I p < 0.01) and in Gr III 1.60 +/- 0.30 (vs Gr II p < 0.02). CONCLUSION: CFR of LAD can be determined in 80% of patients by the synergistic use of high resolution TTCD combined with intravenous given ultrasound echo-enhancing agent. A coronary flow reserve of less than 2.1 detected in this patient cohort significant LAD-stenosis with a sensitivity and specificity of 91% and 76%.

Extent and severity of test positivity during dobutamine stress echocardiography. Influence on the predictive value for coronary artery disease.

AIMS: Recent studies have evaluated the diagnostic accuracy and predictive value of dobutamine echocardiography without considering the additional information implied by the magnitude of induced wall motion abnormalities. We sought to evaluate the positive predictive value of dobutamine echocardiography for coronary artery disease from the extent and severity of the induced wall motion abnormality. In addition, we intended to determine factors associated with false-negative dobutamine echocardiography. METHODS AND RESULTS: Two hundred and eighty-three consecutive patients with suspected coronary artery disease underwent dobutamine echocardiography (up to 40 microg x kg(-1) x min(-1)+atropine up to 1 mg) and coronary angiography. The number of segments and the degree of deterioration were used to describe the extent and severity of induced wall motion abnormality. Analysis of clinical, procedural and echocardiographic variables was performed to determine factors associated with false-negative results. The positive predictive value of dobutamine echocardiography increased from 85% to 90%, 94% and 94% with deterioration of wall motion by one grade in >/=1, >/=2, >/=3 and >/=4 segments, respectively (P<0.05). Deterioration of wall motion by two grades in one segment had a positive predictive value of 96% as compared to 85% for deterioration by only one grade in one segment (P<0.05). Patients with false-negative test results received atropine more frequently (28% vs 13%, odds ration [OR]=3.87, 95% confidence interval [CI]=1.54-9.75, P=0.028) than patients with a correct positive result. However, angina (15 vs 37%, OR=0.26, 95% CI=0.09-0.71, P=0.010), ECG changes during dobutamine stress (15% vs 35%, OR=0.49, 95% CI 0.19-1.25, P=0.014) and high image quality (OR 1.59, 95% CI 1.07-2.37, P=0.015) were less frequent. The sensitivity of dobutamine echocardiography increased from 67% to 71% and 86% (P<0.05) with increasing achieved maximal heart rate (<75%, 75-85% and >85% of maximal heart rate). CONCLUSION: The positive predictive value of dobutamine echocardiography increases significantly as the extent and severity of induced wall motion abnormality increases. Thus, the degree of test positivity should be reported in clinical practice. Despite high pharmacological drug doses, the haemodynamic response may still be insufficient in some patients to induce myocardial ischaemia, resulting in false-negative dobutamine echo tests. To maximize the sensitivity of dobutamine echocardiography, the highest haemodynamic stress level, with a heart rate above 85% of the predicted heart rate, should be reached.

Noninvasive assessment of coronary flow reserve with transthoracic signal-enhanced Doppler echocardiography.

OBJECTIVES: The feasibility of noninvasive assessment of coronary flow reserve (CFR) in the distal left anterior descending artery (LAD) with echocardiography-enhanced transthoracic pulsed wave Doppler guided by high-resolution transthoracic color Doppler (TTCD) was investigated. The results were compared with the degree of coronary diameter stenosis obtained during cardiac catheterization. BACKGROUND: Assessment of CFR has proven to be useful in the selection of patients undergoing invasive treatment of coronary artery disease and in estimating their prognosis. However, CFR could only be determined invasively in everyday practice during catheterization procedures. Recent development of high-resolution TTCD allows transthoracic visualization of distal LAD and supra-apical intramyocardial perforator branches and noninvasive measurement of CFR with pulsed wave Doppler technique. METHODS: CFR was determined by measuring the ratio of pulsed wave Doppler time velocity integral during adenosine-induced hyperemia (140 microgram/kg/min intravenously) to baseline value. If the baseline Doppler signal of LAD flow was insufficient, an echocardiography (echo) enhancer (Levovist) was used. Forty-five patients were examined by TTCD (7-MHz B-mode, 5-MHz color Doppler, and 3.5-MHz pulsed wave Doppler) after coronary angiography had been performed. Group 1 consisted of 15 patients without heart disease, group 2 of 15 patients with 50% to 85% isolated LAD diameter stenosis, and group 3 of 15 patients with >85% LAD diameter stenosis. RESULTS: Peripheral LAD coronary flow at baseline condition was assessed in 40 (88%) patients with TTCD. CFR could be quantified in 36 (80%) of the 45 patients: in 18 patients without echo enhancer, and in 18 patients with echo-enhancing agent. CFR could not be assessed in 9 (20%) patients. CFR in the various groups was as follows: group 1, 3. 13 +/- 0.57; group 2, 2.23 +/- 0.20 (vs group 1: P <.01); and group 3, 1.64 +/- 0.30 (vs group 2: P <.02). CONCLUSION: CFR in the LAD can be determined in 80% of patients with pulsed wave Doppler guided by high-resolution TTCD combined with intravenously administered echo-enhancing agent.

Standardized guidelines for the interpretation of dobutamine echocardiography reduce interinstitutional variance in interpretation.

Subjective interpretation of dobutamine echocardiograms provides only moderate interinstitutional observer agreement if nonunified data acquisition and assessment criteria are applied. The present study was undertaken to evaluate parameters associated with low interinstitutional observer agreement in the interpretation of dobutamine echocardiograms and to analyze whether standardized interpretation criteria improve interinstitutional observer agreement. One hundred fifty dobutamine echocardiograms (dobutamine up to 40 microg/kg/min body weight and atropine up to 1 mg) were evaluated at 5 centers. Clinical, procedural, and echocardiographic parameters were included in the analysis of variables with significant impact on interinstitutional agreement. Standardized interpretative criteria were established, and 90 dobutamine echocardiograms were reanalyzed by 3 observers using a standardized image display. Multivariate analysis demonstrated low image quality (odds ratio [OR] 0.19, 95% confidence interval [CI] 0.08 to 0.45, p=0.0002), low severity of induced wall motion abnormality (OR 0.17, 95% CI 0.07 to 0.40, p <0.0001), and a low peak rate-pressure product (OR 0.93, 95% CI 0.43 to 2.27, p=0.0382) to result in a low interinstitutional agreement. Standardization of image display in cine loop format and of dobutamine stress echo interpretation criteria resulted in improvement in test result categorization as normal or abnormal, with a kappa value of 0.50, compared with 0.39 using the original subjective interpretation. In conclusion, image quality, the severity of induced wall motion abnormalities, and the obtained rate-pressure product have a significant impact on the interpretation homogeneity of dobutamine echocardiograms. Standardization of image display in cine loop format and of reading criteria results in improved interinstitutional agreement in interpretation of stress echocardiograms.

[Noninvasive determination of coronary flow reserve with signal enhanced high resolution transthoracic Doppler color echocardiography]. / Nichtinvasive Bestimmung der koronaren Flussreserve mittels signalverstärkter hochauflösender transthorakaler Farb-Doppler-Echokardiographie.

UNLABELLED: The feasibility of non-invasive assessment of coronary flow reserve (CFR) in the left anterior descending artery (LAD) using echo-enhanced high-resolution transthoracic color Doppler echocardiography (TTCD) was investigated. The results were compared with the degree of coronary diameter-stenosis obtained during cardiac catheterization. CFR has proven to be useful in the selection of patients undergoing invasive treatment of coronary artery disease and in estimating their prognosis. However, CFR could only be determined in everyday practice invasively during catheterization procedures. Recent development of high-resolution TTCD allows transthoracic visualization of distal LAD and supra-apical intramyocardial perforator branches, and non-invasive measurement of CFR. CFR was determined by measuring the ratio of pulsed-wave Doppler time velocity integral during adenosine-induced hyperemia (140 micrograms/kg/min i.v.) to baseline value. If Doppler signal of LAD flow was insufficiently at basal condition, an echo enhancer (Levovist) was used. 45 patients were examined by TTCD (7 MHz B-mode, 5 MHz color Doppler, 3.5 MHz PW Doppler) after coronary angiography had been performed. Group I consisted of 15 patients without heart disease, Group II of 15 patients with 40 to 70% isolated LAD diameter stenosis, and Group III of 15 patients with > 70% LAD diameter stenosis. Peripheral LAD coronary flow at baseline condition was assessed in 40 patients (88%) using TTCD. CFR could be quantified in 36/45 patients (80%), in 18 patients without echo enhancer, and in 18 patients with echo-enhancing agent. In 9/45 patients CFR could not be assessed. CFR in Group I was 3.13 +/- 0.57, in Group II 2.23 +/- 0.20 (vs Group I p < 0.01) and in Group III 1.64 +/- 0.30 (vs Group II p < 0.02). CONCLUSION: CFR of LAD can be determined in 80% of patients by the synergistic use of high-resolution TTCD combined with intravenous given ultrasound echo-enhancing agent.

Frequency of deep vein thrombosis in patients with patent foramen ovale and ischemic stroke or transient ischemic attack.

To evaluate the additional value of transesophageal (TEE) compared with transthoracic (TTE) echocardiography and the role of patent foramen ovale (PFO) and deep vein thrombosis in the work-up of embolic events, patients with presumed cardiac embolic stroke or transient ischemic attack (neurovascular etiology was excluded) were prospectively studied by transthoracic and transesophageal contrast echocardiography. If PFO was detected echocardiographically, PFO size was assessed semiquantitatively and phlebography of both legs was performed. Two hundred forty-two consecutive patients (153 men, 60 +/- 15 years) were studied. In 197 patients, neuroimaging showed evidence of embolic infarction. TEE identified 138 potential cardiac sources of embolism in 111 patients, compared with 69 by TTE (p <0.01) in 59 patients. TEE detected potential cardiac sources in 52 patients with negative TTE examination and was significantly superior compared with TTE for identifying left atrial thrombi, spontaneous echo contrast, PFO, atrial septal aneurysm, and atheroma of the ascending aorta. In patients with a positive TTE, additional diagnostic information by TEE was found in only 6 patients and did not change therapy. Phlebography was performed in 53 patients with PFO and revealed deep vein thrombosis in 5 patients (9.5%); all had medium or large PFOs. Thus, in patients with cerebral ischemia of suspected cardiogenic origin and a normal TTE examination, TEE detects potential causes of embolism in 31% of patients and is therefore of diagnostic relevance. Conversely, in the presence of a diagnostic TTE an additional TEE confers only marginal diagnostic benefit. Deep venous thrombosis was detected in nearly 10% of patients with PFO as the sole identifiable cardiac risk factor. Given that in 4 of 5 patients deep vein thrombosis was clinically silent, phlebography should be performed in patients with medium or large interatrial shunts if paradoxical embolism is suspected.

Transoesophageal stress echocardiography.

Transoesophageal echocardiography has been performed in conjunction with pacing, dobutamine, or dipyridamole stress to detect stress-inducible ischaemia, and has proved to be a highly accurate diagnostic tool. Its advantages of improved image quality and high diagnostic accuracy have to be weighed against the disadvantages of semi-invasiveness and patient discomfort. The existing data on this stress echo modality and on special applications (diastolic dysfunction, ischaemic mitral regurgitation, hibernating myocardium, peri-operative risk assessment) are reviewed.

Analysis of interinstitutional observer agreement in interpretation of dobutamine stress echocardiograms.

OBJECTIVES: This study sought to determine the degree of interinstitutional agreement in the interpretation of dobutamine stress echocardiograms. BACKGROUND: Dobutamine stress echocardiography involves subjective interpretation. Consistent methods for acquisition and interpretation are of critical importance for obtaining high interobserver agreement and for facilitating communication of test results. METHODS: Five experienced centers were each asked to submit 30 dobutamine stress echocardiograms (dobutamine up to 40 micrograms/kg body weight per min and atropine up to 1 mg) obtained in patients undergoing coronary angiography. Thus, a total of 150 dobutamine stress echocardiograms were interpreted by each center without knowledge of any other patient data. Left ventricular wall motion was assessed using a 16-segment model but was otherwise not standardized. No patient was excluded because of poor image quality or inadequate stress level. Echocardiographic image quality was assessed using a five-point scale. RESULTS: Angiographically significant coronary artery disease (> or = 50% diameter stenosis) was present in 95 patients (63%). By a majority decision (three or more centers), the sensitivity, specificity and accuracy of dobutamine echocardiography were 76%, 87% and 80%, respectively. Abnormal or normal results of stress echocardiography were agreed on by four or all five of the centers in 73% of patients (mean kappa value 0.37, fair agreement only). Agreement on the left anterior descending artery territory (78%) was similar to that for the combined right coronary artery/left circumflex artery territory (74%), and for specific segments the agreement ranged from 84% to 97% and was highest for the basal anterior segment and lowest for the basal inferior segment. Agreement was higher in patients with no (82%) or three-vessel coronary artery disease (100%) and lower in patients with one- or two-vessel disease (61% and 68%, respectively). Agreement on positivity or negativity of stress test results was 100% for patients with the highest image quality but only 43% for those with the lowest image quality (p = 0.003). CONCLUSIONS: The current heterogeneity in data acquisition and assessment criteria among different centers results in low interinstitutional agreement in interpretation of stress echocardiograms. Agreement is higher in patients with no or advanced coronary artery disease and substantially lower in those with limited echocardiographic image quality. To increase interinstitutional agreement, better standardization of image acquisition and reading criteria of stress echocardiography is recommended.

Dobutamine stress echocardiography after coronary artery bypass grafting. Transthoracic vs biplane transoesophageal imaging.

Graft failure or progressive native vessel disease can be a serious problem after coronary artery bypass grafting. However, because of poor image quality it may be difficult to evaluate these patients by transthoracic stress echocardiography. The purpose of this study, therefore, was to evaluate the effectiveness of dobutamine stress echocardiography in the detection of myocardial territories with compromised vascular supply (due to either an obstructed native vessel without graft, and obstructed graft, or a native vessel obstructed distal to bypass graft insertion with < or = 50% luminal diameter reduction on angiography) after coronary artery bypass grafting and to determine additional information obtained by biplane transoesophageal stress echocardiography. Sixty patients (54 men, mean age 59 +/- 8.5 years) who had undergone coronary bypass grafting (total number of graft vessels 198) were evaluated from 6 months to 14 years (mean 6.2 years) after surgery. Transthoracic dobutamine stress echocardiography, biplane transoesophageal dobutamine stress echo, and coronary angiography were performed and evaluated by independent examiners. An infusion of dobutamine up to a maximum of 40 micrograms.kg-1.min-1 was administered, and additional atropine (0.25-1.0 mg) was given if 85% of age-predicted maximal heart rate was not reached. Biplane transoesophageal echocardiography was performed in the transgastric short-axis view as well as transoesophageal 4- and 2-chamber views, allowing division of the left ventricle into a 14-segment scheme. Wall motion abnormalities induced with dobutamine stress were used to predict regional vascular insufficiency. A 4-point scale, ranging from 'excellent' (1) to 'impossible' (4) was used to assess each system's ability to evaluate all left ventricular segments. Forty-five patients, of whom 35 were identified by transthoracic echocardiography (sensitivity 78%), had at least one territory with a compromised vascular supply. In 15 patients, the vascular supply was uncompromised, with 13 showing no wall motion abnormalities inducible by transthoracic echocardiography (specificity 86%). However, biplane transoesophageal echocardiography had a higher sensitivity and specificity than transthoracic echocardiography in detecting compromised vascular supply, 93% and 93%, respectively. The former system correctly classified the vascular supplies in 113 of 120 vascular territories (94%), according to whether they were compromised or uncompromised. This was significantly more (P < 0.05) than by classification with transthoracic dobutamine echocardiography, by which system only 102 of the 120 vascular territories were correctly assessed (85%). Compared with the conventional transgastric monoplane short-axis view, examination using three different views via a biplane probe results in a higher sensitivity (93% vs 84%). Assessed on a 4-point scale, the ability to evaluate all left ventricular segments was 2.3 +/- 0.7 (mean +/- SD) for transthoracic echocardiography and 1.7 +/- 0.7 (P < 0.01) for biplane transoesophageal echocardiography. After coronary artery bypass grafting transthoracic dobutamine stress echocardiography has acceptable accuracy in the detection of regional vascular insufficiency. However, this accuracy can be improved using the higher image quality of transoesophageal echocardiography, combined with the advantages of several different views obtained by biplane transoesophageal echocardiography.

[Dobutamine stress echocardiography and perfusion scintigraphy for detection of myocardial ischemia in patients with and without previous myocardial infarct]. / Dobutamin-Stressechokardiographie und Perfusionsszintigraphie zur Erfassung myokardialer Ischamien bei Patienten mit und ohne vorausgegangenen Myokardinfarkt.

UNLABELLED: Dobutamine stress echocardiography has proven to be a method with high diagnostic accuracy in the detection of coronary artery disease. In case of previous myocardial infarction it is of importance to detect additional regions with inducible myocardial ischemia. This study aimed at the detection of inducible ischemia by dobutamine stress echocardiography and stress perfusion scintigraphy in patients without and with previous myocardial infarction. 50 patients without as well as 50 patients with previous transmural myocardial infarction were investigated. In all patients coronary angiography, technetium-99m methoxy-isobutyl-isonitrile (MIBI)-SPECT after bicycle ergometry and dobutamine stress echocardiography (up to 40 mcg/kg/min dobutamine, 1 mg atropine) were performed within 14 days. In patients with previous myocardial infarction dobutamine stress echocardiography and MIBI-SPECT had similar sensitivities (91 vs. 94%, n.s.) and specificities (81 vs. 75%; n.s.) in the detection of significant coronary artery disease. Agreement on the presence or absence of inducible ischemia was 84% (Kappa = 0.60). In patients with previous transmural myocardial infarction sensitivity of stress echocardiography and perfusion scintigraphy in the detection of significant coronary artery disease is lower with 63% and 77%, respectively. In this patient group transient perfusion defects were found more frequently than inducible wall motion abnormalities, 76% and 60%, respectively. There was a lower agreement (76%; Kappa = 0.49) in the detection of abnormal or normal results between dobutamine echocardiography and stress perfusion scintigraphy for this group of patients. CONCLUSION: This study demonstrates high agreement of dobutamine stress echocardiography and stress perfusion scintigraphy in the evaluation of inducible ischemia in patients without previous transmural myocardial infarction and equal diagnostic accuracy in the detection of coronary artery disease. In patients with previous myocardial infarction there is a lower agreement in the interpretation of patients as having ischemia due to negative dobutamine echo results in patients having positive perfusion scintigraphies.

Exercise echocardiography performed early and late after percutaneous transluminal coronary angioplasty for prediction of restenosis.

The purpose of this prospective study was to examine the incidence of exercise-induced ischaemia before and after angioplasty as well as 4 months later by exercise echocardiography, to evaluate the prognostic value of exercise echocardiography performed after angioplasty as regards the development of restenosis and to determine whether serial exercise tests increase the accuracy of detecting angiographically relevant restenosis. Fifty patients (39 males; mean age 52 +/- 9 years) without prior Q wave infarction entered the study protocol. Exercise echocardiography was performed 2 days prior to angioplasty, 13 +/- 6 days after successful angioplasty as well as at routine follow-up angiography 3.8 +/- 1.6 months after angioplasty. Angiographically successful angioplasty was achieved in 94% (47150) of patients, and early and late follow-up examinations were performed in all 47 patients. Average luminal diameter stenosis decreased from 65 +/- 5% to 26 +/- 9% immediately after angioplasty. Control angiography showed significant restenosis in 30% (14147) of patients. Exercise echocardiography before angioplasty was positive in 90%, continued to be positive in 30% of patients after angioplasty and was positive in 43% at control angiography. The exercise echocardiogram performed early after angioplasty had an overall accuracy for prediction of restenosis of 70%, with a positive predictive value of 50%, and a negative predictive value of 79%. Sensitivity for detection of restenosis at control angiography was high (86%), but specificity (76%) was moderate. Exercise echocardiograms showing deterioration from 2 weeks to 4 months after angioplasty were taken as a sign of restenosis and resulted in an increased specificity of 94%. Sensitivity, however, decreased to 36%, indicating that some patients with an early positive stress echo had already suffered restenosis 13 days after angioplasty. In conclusion, exercise echocardiography documents improvement in regional function after angioplasty. However, a significant proportion of patients continue to have a positive exercise echocardiogram even though angioplasty was angiographically successful, probably due to persistent ischaemic regions or early restenosis. While exercise echocardiography performed early after angioplasty is of insufficient value for the prediction of restenosis, if performed at late follow-up it has a good diagnostic accuracy for detecting restenosis.

Evidence for cardioembolic stroke in a case of Kearns-Sayre syndrome.

BACKGROUND: Cerebral infarction is a known complication in patients with mitochondrial encephalomyopathies (MELAS, MERRF, Kearns-Sayre syndrome), but the etiology in the different types remains uncertain. CASE DESCRIPTION: A 33-year-old woman who had suffered from ophthalmoplegia, bilateral ptosis, ataxia, retinitis pigmentosa, and epilepsy since childhood was diagnosed to have Kearns-Sayre syndrome. The diagnosis was confirmed by muscle biopsy when she was 17 years old. A pacemaker was implanted because of the occurrence of bradyarrhythmias when she was 24 years old. The patient was admitted to the hospital with left-sided hemiparesis of sudden onset due to right striatocapsular infarction. Results of Doppler sonography of the carotid arteries were normal; however, transesophageal echocardiography revealed a thrombus in the left atrial appendage. CONCLUSIONS: Stroke in Kearns-Sayre syndrome is likely to be due to cardiac embolism. Anticoagulant therapy should be considered even for mild forms of cardiomyopathies leading to left ventricular dysfunction.

Functional assessment of PTCA results by stress echocardiography: when and how to test.

Angiographic follow-up has shown that restenosis after PTCA is a continuous and ubiquitous process rather than a dichotomous event. Since the functional significance of restenosis involves more factors than minimal lumen diameter, functional tests after PTCA cannot be expected to match exactly the degree of angiographic restenosis. In the past, nuclear perfusion imaging has been the most accurate non-invasive method to predict restenosis, but now there is a new technique: stress echo. This uses physical (treadmill, exercise), pharmacological (dipyridamole, dobutamine), or pacing stress (together with transoesophageal imaging) for the detection of stress-inducible wall motion abnormalities; resolution of resting abnormalities may also be observed. These stress modalities have been employed to detect restenosis in limited numbers of patients, with diagnostic accuracies (so far, except for dobutamine) comparable to nuclear imaging. Therefore, it seems that the decision to use echo stress testing depends on patient characteristics, availability of methods, and, importantly, experience of the echo laboratory. Timing of the test after PTCA must take into account delayed functional recovery after PTCA; this has been well described by nuclear perfusion imaging. Thus, very early (< 1 month) tests lack specificity. On the other hand, development of restenosis after 6 months is rare. Stress tests therefore should be performed within the time window of 1 to 6 months after PTCA.

Incremental value of biplane and multiplane transesophageal echocardiography for the assessment of active infective endocarditis.

In 41 patients with clinical evidence of active infective endocarditis, transesophageal echocardiography was performed in a stepwise manner, starting with evaluation of the monoplane views, followed by the longitudinal plane, and finally by the intermediate planes. Number, location, length, area, density, extent, and mobility of vegetations and abscesses were assessed in the monoplane, biplane, and best intermediate planes to identify and quantify the incremental value of the longitudinal and intermediate planes. Eighty-three vegetations and 6 abscesses were found. In 4 patients (10%) monoplane evaluation yielded false-negative results. There were no false-negative results using the biplane evaluation. However, when compared with multiplane evaluation, additional vegetations were missed in 23% of patients after monoplane and in 9% of patients after biplane evaluation. Three abscesses were missed using the monoplane and 1 was missed using the biplane technique. The area was underestimated in 60% of all vegetations (mean underestimation, 37% +/- 23% [SD] of maximal area) and length in 49% of cases (mean underestimation, 38% +/- 23% [SD] of maximal length) of all vegetations when biplane was compared with multiplane evaluation. Also, with monoplane and biplane evaluation, mobility and density were misinterpreted in 6% and 5% and 17% and 9% of all vegetations, respectively. Thus, multiplane transesophageal echocardiography is more accurate than the monoplane and biplane techniques in assessing patients with active infective endocarditis.

Advances in noninvasive assessment of valvular heart disease.

Echocardiography continues to be the noninvasive method of choice in the evaluation of valvular heart disease. Important recent developments include clinical validation of approaches used to quantify valvular regurgitation, in particular the proximal flow convergence zone method; use of transesophageal imaging to monitor and evaluate surgical or percutaneous interventions in valvular heart disease, in particular mitral valve repair; insight into flow-related stretch of the orifice area in aortic stenosis; and validation of nuclear magnetic resonance imaging in small series for quantification of left-sided valvular stenotic and regurgitant lesions.