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F A Flachskampf

Publications and source records attributed to F A Flachskampf.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Transesophageal Doppler echocardiography assessment of mitral valve insufficiency: Comparison of jet area, pulmonary venous flow profile, proximal jet diameter, maximal regurgitation flow rate and regurgitation orifice area with angiography].

UNLABELLED: In transesophageal echocardiography several methods have been used to grade mitral regurgitation. For a direct comparison of these techniques, 36 patients (60 +/- 13 years) with native mitral regurgitation underwent multiplane transesophageal echocardiography and angiography within 5 days. We compared the following measurements: 1) The maximal color jet area of mitral regurgitation, 2) the ratio of maximal systolic to diastolic pulmonary venous flow velocity in the left upper pulmonary vein, 3) the proximal jet width of mitral regurgitation, 4) the maximal regurgitant flow rate Qmax, measured by the proximal convergence method, 5) the regurgitant office area Areg, calculated by dividing Qmax by maximal regurgitant velocity obtained by continuous wave Doppler. RESULTS: The correlation between color jet area (r = 0.4; p < 0.05) or pulmonary venous flow (r = -0.3; p = n.s.) with angiographic severity of mitral regurgitation is low. The sensitivity of the retrospective best cut-off values is 69% (color jet area) and 83% (pulmonary venous flow). Using retrospective best cut-off values all patients with mitral regurgitation Sellers grade III and IV are correctly identified by a proximal jet width > or = 0.7 cm, Qmax > or = 300 ml/s or a Areg > or = 0.5 cm2 (sensitivity and specificity of 83-100%). Spearman's rank coefficient demonstrated a high correlation (r = 0.75-0.77; p < 0.001) between proximal jet width, Qmax and Areg and with angiographic severity. CONCLUSION: Multiplane transesophageal echocardiographic grading of mitral regurgitation by proximal jet width or proximal convergence zone shows comparably good results and is clearly superior to grading by color jet area or pulmonary venous flow, if adequate image quality is achieved.

Adult↗
PubMed1997

[Overestimation of regurgitation velocities of intact mechanical heart valve prostheses and other small orifices with 10 mm2 Doppler echocardiography].

A systematic evaluation of the accuracy of continuous wave echo Doppler measurements across prosthetic valve leakages and regurgitant lesions has not been performed. Continuous echo Doppler velocity measurements in an in vitro, steady flow model, across the leaks of 12 intact mechanical prostheses and across six circular nozzles (area, 0.5-20 mm2) at pressure drops between 30 and 105 mm Hg were analyzed and compared to the velocities predicted by the modified Bernoulli equation. Laser Doppler anemometry of flow velocities through the nozzles was performed in addition. Despite excellent correlation, there was substantial overestimation of "Bernoulli predicted"-velocities by echo Doppler in the prosthetic leaks (mean +12.3 +/- 9.4%; range, 90.3-143.4%). Also in nozzles < or = 10 mm2, but not in those > 20 mm2, an overestimation of the "Bernoulli predicted"-velocities was observed (mean +6.2 +/- 2%). Laser Doppler anemometry of flow velocities through the nozzles showed slightly lower values than predicted by the Bernoulli equation. This effect apparently is due to transit time effects leading to spectral broadening and should be taken into account when using echo Doppler measurements in very small (< 10 mm2) orifices, such as mild to moderate regurgitant lesions and prosthetic valve leakage.

Artifacts↗
PubMed1997

Determination of left ventricular mass and circumferential wall thickness by three-dimensional reconstruction: in vitro validation of a new method that uses a multiplane transesophageal transducer.

Elevated left ventricular mass and increased wall thickness have important prognostic implications in clinical medicine. However, these parameters have been incompletely characterized by one- and two-dimensional echocardiography. Therefore this study was performed to validate in vitro measurement of left ventricular mass and circumferential wall thickness with a multiplane transesophageal transducer and three-dimensional reconstruction. Results for mass measurements were also compared with a standard method for the determination of left ventricular mass, the Penn convention. Fourteen necropsied left ventricles were scanned in a water bath by a volume-rendering, three-dimensional reconstruction system. There was an excellent correlation and high agreement for determination of three-dimensional left ventricular mass (r = 0.98; standard error of the estimate [SEE] = 9.6 gm; y = 1.02x + 0.46) and wall thickness (r = 0.93; SEE = 1.4 mm; y = 0.95x + 1.64) compared with anatomic measurements. Left ventricular mass by a simulated Penn convention revealed a lower correlation and larger error compared with three-dimensional measurements (r = 0.72; SEE = 42.8 gm; y = 1.01x + 9.61). Therefore determination of left ventricular mass by three-dimensional reconstruction was validated in vitro and was superior to one-dimensional echocardiographic methods.

Algorithms↗
PubMed1997

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.

Angioplasty, Balloon, Coronary↗
PubMed1996

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.

Cardiotonic Agents↗
PubMed1996

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.

Aged↗
PubMed1996

Left ventricular volume calculations using a multiplanar transoesophageal echoprobe; in vitro validation and comparison with biplane angiography.

BACKGROUND: Biplane angiographic and transthoracic echocardiographic volume calculations have shown to be sufficiently reliable in symmetric hearts; however, they are unreliable in the presence of aneurysmatic distortions. Multiplane transoesophageal echocardiography offers unobstructed cross-sectional views of the heart from one stable transducer position with the potential of imaging irregular cavity forms more accurately. It was the purpose of this in vitro study to compare the precision of multiplanar transoesophageal echocardiography to that of biplane angiography in determining left ventricular volumes, especially in aneurysmatic models. METHODS: Seven silicon rubber models of the left ventricle from post-mortem specimens (four with aneurysms) were filled with 30 different volumes (range 153-256 ml, 197 +/- 30 ml). Echocardiographic cross-sections (20 degree rotational steps) were obtained from different transducer positions, utilizing a multiplanar probe with a central rotational axis. Volumes were calculated using the disc-summation method. For comparison the same volumes were determined by standard biplane angiography. The minimum number of echo cross-section necessary to optimize precision was analysed by calculating volumes for each increasing equidistant rotational step. RESULTS: Linear correlation between measured volume using a multiplanar transoesophageal echoprobe and true volume was high (r = 0.97) and significantly better than for biplane angiography (r = 0.88; P < 0.001). Measurement bias and imprecision were also significantly lower with multiplanar echocardiography than with biplane angiography (3.9 +/- 7.1% vs 11.1 +/- 15.4%, and 2.0 +/- 3.7% vs 5.9 +/- 8.3%; P < 0.001). Precision of biplane angiographic volume measurements was significantly influenced by the presence of aneurysmatic distortions. Multiplanar echo volumes, however, were not influenced by left ventricular geometry and transducer positions. Nine echo cross-sections provided optimal precision. CONCLUSIONS: Three-dimensional echocardiographic volume calculations using a multiplanar transoesophageal echoprobe and the disc-summation method provide precise measurements unaffected by left ventricular geometry and transducer position in an in vitro setting. Standard biplane angiography is significantly less precise.

Angiography↗
PubMed1996

[Dobutamine stress echocardiography and perfusion scintigraphy for detection of myocardial ischemia in patients with and without previous myocardial infarct].

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.

Adult↗
PubMed1996

[Quadricuspid aortic valve: diagnosis by multiple transesophageal echocardiography].

The case of a quadricuspid aortic valve diagnosed in adult age is reported. A 67-year-old patient, who had no previous diseases or cardiovascular complaints, presented in the clinic for an embolic occlusion of the left retinal artery. Isolated moderate aortic regurgitation was diagnosed clinically and echocardiographically. For its further evaluation and for seeking embolic sources, multiplane transesophageal echocardiography was performed, which discovered a quadricuspid aortic valve as the cause of aortic regurgitation and major atherosclerotic lesions in the ascending aorta and the aortic arch as possible cause of the embolic event. The fourth, accessory cusp, smaller than the other three, was localized between the non-coronary and left coronary cusp. In the short axis view the quadricuspid aortic valve showed in diastole a "X"-configuration, with a persistent central orifice between the commissures, which was the cause of the regurgitation jet in color Doppler examination, and in the systole a trapezoid opening pattern. In the long-axis view the valve showed a tricuspid closing pattern. The quadricuspid aortic valve can be exactly diagnosed by multiplane transesophageal echocardiography.

Aged↗
PubMed1995

Long-term clinical and echocardiographic follow-up after surgical correction of hypertrophic obstructive cardiomyopathy with extended myectomy and reconstruction of the subvalvular mitral apparatus.

BACKGROUND: The standard surgical approach to hypertrophic obstructive cardiomyopathy (HOCM) was modified in the present series with a combination of extended myectomy with partial excision and mobilization of the papillary muscles. METHODS AND RESULTS: Between 1979 and 1992, 58 patients (38 men and 20 women; mean age, 49 +/- 24 years) with HOCM were operated on with the use of this different technique. Their intraventricular gradients were 79 +/- 33 (+/- SD) mm Hg at rest and increased to 147 +/- 48 mm Hg with provocative maneuvers. Mild-to-moderate mitral regurgitation was present in 60% of the patients, and severe regurgitation was present in 5%. Ten patients required additional aortocoronary bypass graft surgery. Follow-up (mean, 84 months) was complete (100%). Hemodynamic improvement was documented by a significant (P < .01) decrease in left ventricular end-diastolic pressure from 19 +/- 9 to 14 +/- 6 mm Hg and reduction of basal outflow tract gradients to 5 +/- 7 mm Hg at rest and 16 +/- 24 mm Hg after provocation. Late mortality was 1.4% per patient-year, and no sudden cardiac deaths occurred during follow-up. Functional status was excellent for 84% of the patients; 8 patients were in New York Heart Association functional class III, and none were in class IV. Echocardiography revealed no outflow tract obstruction. CONCLUSIONS: Extended myectomy and reconstruction of the subvalvular mitral apparatus in HOCM result in excellent functional improvement with relief of outflow tract obstruction. The technique can be performed safely despite its more aggressive surgical nature and allows an individualized strategy depending on the patient's extent and distribution of left ventricular hypertrophy.

Adolescent↗
PubMed1995

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.

Abscess↗
PubMed1995

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.

Angioplasty, Balloon, Coronary↗
PubMed1995

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.

Adult↗
PubMed1995

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.

Blood Flow Velocity↗
PubMed1995

Application and perspectives of transesophageal stress echocardiography using monoplane and biplane instruments.

Transesophageal stress echocardiography has been reported to have a high sensitivity and specificity for noninvasive identification and assessment of coronary artery disease. Its advantage is the virtually never obstructed acoustic window on the heart yielding superior image quality in almost all patients. Pharmacological stress as well as simultaneous atrial pacing--attaching electrodes to the echoscope--have been applied as stress modalities. Both transesophageal stress echocardiography modalities have been shown to be well tolerated, safe, and feasible in most patients. These promising initial experiences led to clinical application of this method for preoperative risk evaluation, for detection of restenosis after PTCA, and for evaluation of hibernating myocardium. This technique was also successful for evaluation of stress induced changes of transmitral and pulmonary venous flow in patients with left ventricular hypertrophy and coronary artery disease. Although all studies published so far were performed with monoplane technique, the sensitivity for detection of one-vessel and, even more so, multivessel disease was high. However, apical and basal wall-motion abnormalities may go undetected using monoplane equipment. The advent of biplane transesophageal imaging enables the visualization of more ventricular segments. Future studies will show to which degree biplane transesophageal stress echocardiography improves the diagnostic accuracy.

Angioplasty, Balloon, Coronary↗