Uwe Nixdorff

Prediction of Rapid versus Prolonged Healing of Infective Endocarditis by Monitoring Vegetation Size

The diagnostic value of transesophageal echocardiography in monitoring the clinical course has been evaluated in 83 patients with echocardiographic evidence of infective endocarditis. A total of 103 vegetations attached to the aortic or mitral valves were detected by use of the transesophageal approach. The patients were monitored for a mean of 74 weeks and underwent a minimum of two consecutive transesophageal echocardiographic examinations. Group A included patients with increasing or remaining constant size of vegetation (8.2 +/- 1.5 to 11.2 mm, p less than 0.05) during 4 to 8 weeks of antimicrobial therapy, whereas group B was formed by patients with decreasing vegetation size (8.3 +/- 0.8 to 4.9 +/- 0.8 mm, p less than 0.05). The incidences of complications after diagnosis and onset of therapy was higher in group A than in group B: valve replacement (45% versus 2%, p less than 0.05), embolic events (45% versus 17%, p less than 0.05), perivalvular abscess formation (13% versus 2%, p less than 0.05), and mortality (10% versus 0%, respectively, p less than 0.05). Staphylococcus aureus was the most frequent organism isolated in group A (44% versus 11% in B, p less than 0.05) and Streptococcus viridans in group B (33% versus 18% in A, p less than 0.05). Blood cultures were negative in nearly 50% of the patients in each group. There was no difference in the incidences of complications in patients with positive or negative blood cultures. We conclude that an increase in vegetation size during antibiotic therapy predicts a prolonged healing phase of infective endocarditis. This prolonged healing period is associated with a significantly increased risk of complications, independent of blood culture results. Monitoring vegetation size contributes important information concerning prognosis and stage of risk, and it aids in the choice of patient management in infective endocarditis. Because embolic events after diagnosis and onset of treatment are less frequent in rapid-healing endocarditis, surgery cannot be recommended to prevent further events taking into account the high risk of surgery.

Detection of thromboembolus of the right pulmonary artery by transesophageal two-dimensional echocardiography

Abstract Standard diagnostic procedures in patients with suspected pulmonary artery embolism are ventilationperfusion lung scan and pulmonary artery angiography. Some indirect signs can be detected by echocardiography. 1–3 Direct visualization of pulmonary embolism has been described previously. 4,5 Transthoracic echocardiography is of limited value in approximately 20 to 30% of patients because of thorax deformity, adiposity, lung emphysema or mechanical ventilation. Using transesophageal 2-dimensional echocardiography, assessment is possible in these patients with high resolution. 6

Exercise echocardiography for the evaluation of patients after nonsurgical coronary artery revascularization

OBJECTIVES The purpose of this study was to demonstrate the accuracy of stress echocardiography for detecting the progression of coronary artery disease after nonsurgical revascularization. BACKGROUND The expanding role of nonsurgical coronary revascularization procedures mandates the development of sensitive noninvasive techniques for the detection of recurrent ischemia. METHODS Bicycle stress echocardiography was performed in a series of 86 patients 6.5 +/- 1.3 months after a revascularization procedure. Seven patients were excluded from analysis because of poor echocardiographic image quality. RESULTS Digital analysis achieved a sensitivity of 83% for the entire group and a specificity of 85% for stress echocardiographic detection of significant coronary artery disease. Sensitivity was greater in patients with (88%) than in those without (75%) prior myocardial infarction, but this difference did not reach statistical significance. Additional analysis using an increase in end-systolic volume index or a decrease in ejection fraction during stress as an additional marker for ischemia tended to enhance sensitivity (90% for the entire group and 93% for the subgroup with prior myocardial infarction). CONCLUSIONS Stress echocardiography is a useful and sensitive method for the follow-up of patients undergoing nonsurgical revascularization procedures. The addition of volume determination to routine wall motion analysis may be helpful in patients with prior infarction who have scar tissue that may be difficult to distinguish from an adjacent exercise-induced wall motion abnormality.

Tissue Doppler echocardiography: a new method of evaluating perfusion-dependent myocardial function during PTCA

The increasing demand for insight into the relationship between coronary perfusion and myocardial function stimulated the development of tissue Doppler echocardiography. This new technique was applied simultaneously with PTCA of a subtotal LAD lesion (single vessel disease, no collaterals) in a 68-year-old patient suffering from unstable angina pectoris. Prior to the conventional signs of ischaemia a decrease in myocardial tissue velocities and a loss of color-coded heart cycle intervals was observed. A myocardial velocity gradient calculated from the higher subendocardial and lower subepicardial velocity decreased from 3.3 to 1.3. This decrease was prevented by an active autohaemoperfusion device which supplied blood distally to an insufflated balloon (60 ml/min). Thus, contractility and viability might be maintained by preserving myocardial velocity gradients.

Long-term follow-up of global and regional left ventricular function by two-dimensional echocardiography after thrombolytic therapy in acute myocardial infarction

In order to evaluate changes in left ventricular volumes and regional left ventricular function after thrombolytic therapy in acute myocardial infarction serial two-dimensional echocardiography was performed during a follow-up of 2 years in 206 consecutive patients treated with streptokinase and adjunctive angioplasty in a randomized group of patients. Unexpected progressive left ventricular enlargement was detected both with and without angioplasty. In anterior wall infarction, end-diastolic volume index increased from 55 +/- 14 to 91 +/- 28 ml/m2 (+65%, P < 0.01) and end-systolic volume index increased from 31 +/- 11 to 55 +/- 23 ml/m2 (+79%, P < 0.01), whereas ejection fraction decreased from 45 +/- 9 to 41 +/- 7% (-9%, P = NS). Averaged regional anterior wall motion improved during the first 4 weeks (11 +/- 10 to 16 +/- 12%), but subsequently deteriorated (16 +/- 12 to 10 +/- 6, P < 0.05). The number of segments with pathological wall motion increased. Similar volumetric and regional wall motion data were demonstrated in inferior wall infarction. We believe this reflects a chronic ventricular remodelling phenomenon. This process takes place predominantly during the first 3 months, but continues over the whole follow-up period. Forty percent of the patients suffered symptoms of heart failure on long-term follow-up. Attenuation of progressive ventricular enlargement remains a therapeutic challenge in the long-term care of these patients. Angiotensin-converting enzyme inhibitors are promising agents in this regard.

Sum of ST-segment elevations on admission electrocardiograms in acute myocardial infarction predicts left ventricular dilation

In summary, ST-segment elevations on the admission electrocardiogram not only diagnose acute myocardial infarction but also provide predictive information with respect to developing infarct size and left ventricular remodeling as well as survival.

Dobutamine stress Doppler echocardiography: reproducibility and physiologic left ventricular filling patterns

Qualitatively, dobutamine stress echocardiography has become an established procedure. Quantitative results are in great demand but this is still difficult due to limited endo- and epicardial border definition. Transmitral Doppler variables are strictly quantitative and less subjective. Furthermore, ischemic alterations precede systolic ones (ischemic cascade). There are preliminary reports of the utility of dobutamine stress Doppler echocardiography, but proof of reproducibility and left ventricular filling patterns are still lacking. Fourteen healthy volunteers (10 men, 4 women, median age 25.9 years, range 21-32 years) were investigated according to the usual dobutamine stress echocardiographic protocol (5, 10, 15, 20, 30, 40 and 40 micrograms/kg/min + 0.5 mg atropine). At each titration step a standardized transmitral PW-Doppler recording with the sample volume positioned at the opened mitral leaflet tips was analyzed three times by two independent, experienced investigators. Of the early, late, and mean velocities (VmaxE, VmaxA, Vmean), time integrals (VTI-E, VTI-A, VTI), their ratios (E/A, E/A VTI), and various time intervals (Tacc, Tdec, E- and A-duration, FillT), VmaxE (0.82 to 1.09 m/s; P < 0.0001), VTI-E (16.17 to 17.19 cm; P < 0.0001) and Vmean (0.29 to 0.82 m/s; P < 0.0001) were found to have the greatest discriminatory power, commencing already at a dose of 10-15 micrograms/kg/min dobutamine. VmaxE and VTI-E demonstrated the smallest intra- and interobserver variation without any increase in variability during incremental dose titration. Assessment of the early diastolic filling pattern by Doppler echocardiography is a valuable quantitative and reproducible adjunct to conventional dobutamine stress echocardiography. Further controlled studies in coronary artery disease patients have to confirm, whether lower dobutamine doses could be used in the test and sensitivity increased due to better data acquisition in cases of limited echogenicity, less subjectivity, and earlier onset of ischemic alterations.

Diagnose eines intramyokardialen Hämatoms nach traumatischem Myokardinfarkt durch Magnetresonanztomographie

Thoraxverletzungen treten bei etwa 30% aller traumatisierten Patienten auf, wobei in den meisten Fällen Verkehrsunfälle die Ursache sind. Wir berichten über den Fall eines Patienten, der nach einem Skiunfall einen traumatischen Vorderwandinfarkt erlitt. Im weiteren Verlauf kam es zu einer ausgedehnten intramyokardialen Einblutung. Differentialdiagnostisch kam zunächst ein linksventrikuläres Pseudo- bzw. Pseudopseudoaneurysma in Frage, kernspintomographisch konnte jedoch durch den Nachweis eines schmalen Myokardsaums sowohl ventral als auch dorsal der Raumforderung die Diagnose eines intramyokardialen Hämatoms gestellt werden. Bei dem Patienten wurde daraufhin eine aortokoronare Bypass-Operation sowie eine Resektion des intramyokardialen Hämatoms durchgeführt. Die Diagnose konnte intraoperativ sowie histologisch bestätigt werden. Traumatic cardiac lesions occur in about 30% of all traumatized patients, in most cases they are due to traffic accidents. We report a patient who suffered from a traumatic anterior wall infarction following a ski accident. Consecutively, an extended intramyocardial hemorrhage occurred. A left ventricular pseudoaneurysm was considered first by echocardiography. Using MRI, an intramyocardial hemorrhage could be diagnosed because of a thin myocardial border surrounding the hematoma. Consecutively, the patient underwent CABG surgery as well as a resection of the intramyocardial hematoma. This diagnosis could be manifested surgically and histologically.

High-Frequency Rotational Angioplasty

High-speed rotational coronary atherectomy is an alternative method to treat complex, especially calcified coronary stenoses. A rotating burr tip removes the occlusive plaque tissue. The applied rotating frequency is between 160 000 to 190 000 rpm. The primary technical success-rate for high frequency rotational atherectomy alone yields between 50 to 60% on average. Associated with consecutive additional balloon angioplasty, the success rate is between 80 and 95% when treating complex type B II or C stenoses. Today, the usage of a single burr tip size with adjunctive balloon angioplasty has become a standard procedure. The occurrence of serious complications such as extensive dissections or thrombotic vessel occlusion is a rare phenomenon after high-speed rotational atherectomy compared to coronary balloon angioplasty, whereas coronary spasm is more common after high-speed rotational atherectomy. According to the actual results, high-speed rotational angioplasty did not lower the rate of long-term restenosis, compared to the results achieved by balloon angioplasty alone. The rate of long-term restenosis is reported to be between 40 to 50% after highspeed rotational angioplasty with or without adjunctive balloon angioplasty.

Dynamic stress echocardiography for evaluating anti-ischemic drug profiles in post-MI patients

Exercise ECG is an established method of evaluating the anti-ischemic properties of drugs. However, there are considerable methodologic limitations to this procedure and its use is restricted to patients with exercise-provoked ECG alterations which can be interpreted as ischemia. The principal, earlier onset of wall motion abnormalities according to the ischemic cascade can be detected by stress echocardiography and might be utilized as a pharmacological stress testing modality. Sixteen consecutive patients (15 men, one woman; 53 ± 9 years old) with angiographically proven coronary artery disease (8 with one-, 5 with two-, and 3 with three-vessel disease) and exercise-induced wall motion abnormalities were examined by dynamic stress echocardiography (50 watt followed by 20-watt increases/min). Anti-ischemic drugs were withdrawn prior to and on day 1; on the following day 2, 0.2 µg/kg/min nisoldipine was infused intravenously during the test after a 3 µg/kg bolus was given. At maximum comparable workload 15/16 patients showed an improved wall motion score on treatment (day 1: 22.9 ± 4.9 vs day 2: 20.0 ± 3.9; normal score: 12; one-sided binomial test: p = 0.0003). Eight of 16 patients demonstrated ST-segment deviations on day 1 and day 2. The double product did not differ at any workload stage until the maximum of 130 watt (day 1: 14101 ± 3140 vs day 2: 13365 ± 2865; n.s.). Dynamic stress echocardiography seems to be a valuable tool in pharmacologic stress testing and in terms of accuracy is supposed to be superior to conventional exercise ECG. Nisoldipine reduces exercise-induced wall motion abnormalities in patients with and without exercise-induced ECG alterations. The data result from a controlled pilot study, and further studies are required to confirm these promising methodological and therapeutic findings.