Heinz Völler

Improvement of endocardial border delineation in suboptimal stressechocardiograms using the new left heart contrast agent SH U 508 A

Recent studies have shown that the saccharide based echocardiographic contrast agent SH U 508 A opacifies the left ventricle after i.v. injection, thus possibly improving endocardial border definition. This study was performed to determine whether SH U 508 A can enhance the wall motion analysis in suboptimal echocardiographic images at rest and following pharmacological stress. Ten male patients (mean 58 years) exhibiting ≥30% endocardial border dropout were examined prior to a diagnostic left heart catheterization. Five patients were stressed with Dobutamine, 5 with Dipyridamole. The wall motion was assessed visually (qualitatively) as well as computer-aided (quantitatively). The concordance between left ventricular angiography as ‘gold standard’ and resting echocardiography regarding the wall motion analysis was significantly improved from 64.5% to 90.3% following the injection of SH U 508 A (p < 0.05). A delineation score (0 = not delineated, 1 = delineated) of 12 individual wall segments was used. The mean delineation score at baseline was 6.1 ±1.4 at rest and 6.6 ±1.9 during stress. SH U 508 A significantly (p < 0.01) increased the score to 9.6 ±1.9 and 10.3 ±1.7, respectively. The intraobserver variability for assessing the delineation score was significantly (p < 0.04) improved by SH U 508 A. SH U 508 A, however, did not improve the quantitative assessment of the left ventricular function. Only 40% of the patients could be analyzed following SH U 508 A injection. No severe adverse reactions were seen. SH U 508 A led to a significant, clinically important, improvement in the interpretation of stress echocardiograms in patients with inconclusive routine echocardiograms.

Comparison of the Prognostic Value of Dipyridamole and Dobutamine Stress Echocardiography in Patients With Known or Suspected Coronary Artery Disease

Direct comparison of the utility of dipyridamole stress echocardiography and dobutamine stress echocardiography was performed to identify patients at risk of future cardiac events in 134 patients with suspected or known coronary artery disease. The predictive values of dobutamine and dipyridamole were remarkably similar.

Comparison of the diagnostic potential of four echocardiographic stress tests shortly after acute myocardial infarction: submaximal exercise, transesophageal atrial pacing, dipyridamole, and dobutamine-atropine

This study assessed and compared the diagnostic potential of submaximal exercise, transesophageal atrial pacing, dipyridamole, and dobutamine-atropine stress echocardiography tests shortly after acute myocardial infarction. In 121 study patients, 325 digital echocardiographic stress tests were attempted 10 to 11 days after acute myocardial infarction: 83 submaximal exercise tests, 121 high-dose dipyridamole echocardiography tests (DET), 69 transesophageal atrial pacing tests (< 150 beats/min), and 52 dobutamine tests, starting at 10 microgram/kg per minute, increasing stepwise to 40 microgram kg/min, and coadministering atropine in 12 patients (dobutamine-atropine stress echocardiography [DASE]). Results were correlated to a coronary artery diameter stenosis > or = 50% as determined by quantitative angiography. Feasibility to perform submaximal exercise echocardiography, atrial pacing echocardiography, DET, and DASE was 89%, 52%, 98%, and 88%, respectively. Atrial pacing was not tolerated by 18 patients and refused by 6 (9%). Severe but not life-threatening side effects were hypotension in DET (2%) and tachyarrhythmias in DASE (6%). Test positivity in multivessel disease with submaximal exercise, DET, and DASE was 55%, 93%, and 90%, respectively, and in 1-vessel disease 47%, 65%, 71%, and for atrial pacing, 82%, respectively. We conclude that submaximal exercise has limited sensitivity and atrial pacing limited feasibility. The pharmacologic stressors provide a useful, safe diagnostic approach: DET with slightly lower sensitivity in 1-vessel disease and DASE with insignificantly less feasibility.

Evaluation of late cardiotoxicity with pulsed Doppler echocardiography in patients treated for Hodgkin's disease

Summary. The impact of valvular, myocardial and pericardial abnormalities on cardiac haemodynamics in patients treated for Hodgkins disease with COPP/ABVD with and without mediastinal irradiation was determined in 49 patients 2–10 years after induction therapy. Diagnostic procedures to evaluate cardiac function consisted of history, physical examination, exercise bicycle stress test, M‐mode two‐dimensional and pulsed Doppler echocardiography. No patient reported symptoms related to cardiomyopathy, and only one of the 49 had evidence of coronary heart disease. Pericardial thickening was seen on echocardiograms in 19/49 patients (38.8%), valvular thickening in 21/49 (42·9%), and reduced fractional shortening in 9/49 (18·4%). The Doppler‐derived mean E and A (±SD) of transmitral flow were 0·75 ± 0·14 m/s and 0·56 ± 0·09 m/s, respectively, in patients receiving chemotherapy and 0·81 ± 0.19 m/s and 0·63 ± 0·20 m/s in those with additional mediastinal irradiation. There was no statistically significant difference between mean E and A in transmitral flow in patients treated for Hodgkins disease and control subjects. Furthermore, the transtricuspid and hepatic vein flow velocities did not differ significantly. Although the present study demonstrates high frequencies of pericardial and valvular thickening in patients treated for Hodgkins disease with the COPP/ABVD regimen with or without mediastinal irradiation, it showed no impact on cardiac flow velocities. The abnormalities might thus be of minor clinical relevance in these patients.

Heart rate variability from Holter monitoring in a normal population

The determination of the normal heart rate variability (HRV) range in the time and frequency domain with a commercially available Holter monitoring system in a group of carefully selected normal subjects is addressed. Spectral analysis of HRV using the fast Fourier transformation technique revealed total-, low-, and high-frequency standard variation. Time-domain HRV parameters were also calculated from the same recording. The total-, low-, and high-frequency standard deviation as well as the pNN50 were found to be lower in subjects over 45 yrs than in those under (p=0.04-0.07). Furthermore, gender-related differences in HRV were also observed: the total- and low-frequency standard deviation as well as the standard deviation of all normal coupling intervals were lower in women than in men (p=0.002-0.06). The authors conclude that HRV in normals is age- and gender-related.<<ETX>>

Cranial Computerized Tomography Stroke Patterns in Patients with Cardiac Sources of Embolism, Extracranial Large-Artery Disease or No Extracranial Source

The hypothesis of an association between stroke mechanisms (cardiac sources of embolism, extracranial large-artery disease, hypertension) and cranial computerized tomography stroke patterns was tested in a prospective study. 200 consecutive patients with focal brain ischemia were investigated by echocardiography (transthoracic and transesophageal approach), Doppler sonography, electrocardiography, and cranial computerized tomography (rated masked). Except for low-flow infarcts and carotid artery stenoses the association between stroke mechanisms and stroke patterns was weak. Lacunes were found with almost equal frequencies in patients with cardiac sources of embolism, extracranial large-artery disease or no extracranial source (with or without hypertension). The predictive value of cranial computerized tomography stroke patterns for the finding of possible stroke mechanisms is low. An embolic etiology of lacunes cannot be excluded.

Factors influencing the diagnostic accuracy of dobutamine stress echocardiography

Background: While Dobutamine stress echocardiography is a well established tool, the range of the diagnostic accuracy found in the literature is rather large. The main reason for this is the fact, that different test protocols were used. Aim of this study was to assess the effects of both addition of atropine as well as consideration of a hyperdynamic response while interpreting the stress echocardiogram on the diagnostic accuracy. Methods and results: 120 consecutive patients were examined and divided into the following groups: A) achieving their age predicted heart rate with dobutamine, B) termination of the test due to ischemia, C1) negative test without reaching the predicted heart rate, and C2) C1 following addition of atropine. All of the echocardiograms were analyzed twice: 1) regarding the lack of a hyperdynamic response to dobutamine as ischemia (Hyper analysis), and 2) ignoring the hypercontractility (Conventional analysis). The accuracy of A and B were 88% and 90% resp. Group C1 had a very poor accuracy of 60%. This rose significantly (p < 0.01) after atropine (C2 = 84%), without leading to an increase of adverse effects. Conventional wallmotion analysis lead to an overall accuracy of 87% (groups A, B, and C2), while Hyper analysis showed an accuracy of 90% (p < 0.01). Conclusions: To achieve a high accuracy Dobutamine stress echocardiography should always be combined with atropine to reach a target heart rate. The wallmotion analysis should be based on the assumption that a hyperdynamic response to dobutamine is normal, while its lack is indicative of ischemia.

Acute alterations of pre- and afterload: Are Doppler-derived diastolic filling patterns able to differentiate the loading condition?

The net effects of acute changes in pre- and afterload on left ventricular filling, were examined by altering loading conditions in normal subjects. The specific purpose of this study was to investigate whether Dopplerderived transmitral flow patterns are able to differentiate the type of loading conditions. In 24 normal subjects (13 females, 11 males, mean age 44.1±11.5 years), the following Doppler variables were determined at baseline, after rapid volume infusion (preload increase), after nitroglycerin administration (preload decrease), during isometric exercise (afterload increase), and after application of a converting enzyme inhibitor (afterload decrease): the peak and integrated early (E, Ei) and late (A, Ai) diastolic flow velocities, their ratios (E/A, Ei/Ai), the percentage of atrial contribution (ACON), and the acceleration and deceleration times (Ac, dc) of early filling. Reduced preload and increased afterload led to similar filling patterns characterized by a significant E and Ei decrease (p<0.05, compared to baseline) accompanied by an A and Ai increase with a resultant reduction of E/A and Ei/Ai. Both changes increased the atrial contribution to filling and reduced Ac and dc. Increased preload only significantly increased E and Ei, while reduced afterload did not induce any significant changes.Different loading conditions alter Doppler-derived diastolic filling patterns. However, the transmitral flow profile is not specific enough to distinguish the manner in which loading conditions have been altered.

Messung der Belastungshämodynamik im kleinen Kreislauf in der stationären Phase nach Myokardinfarkt: Eine zu Recht “vergessene” Untersuchung?

Bei 123 konsekutiven Patienten mit akutem Myokardinfarkt und systemischer Lyse wurde 7–10 Tage nach Infarkt in gleicher Sitzung wie der Linksherzkatheter auch ein Rechtsherzkatheter (RHK) mit ergometrischer Belastung durchgeführt. Nach 6 Monaten wurden beide Untersuchungen wiederholt. Es sollte untersucht werden, ob der RHK das Ergebnis der Koronarographie, d.h. das Vorliegen einer 1-, 2- oder 3-Gefäß-Erkrankung, das Ergebnis der Ventrikulographie, speziell die globale Ventrikelfunktion, und insbesondere den möglichen Profit von einer Intervention (PTCA/OP) beim Postinfarktpatienten voraussagen kann. Ergebnisse: 1. Ruhe- und Belastungshämodynamik korrelieren nicht zum Ausmaß der Koronarerkrankung. Es gibt jedoch eine Korrelation zwischen Belastbarkeit und Anzahl der stenosierten Koronarien. 2. Ruhe- und Belastungshämodynamik korrelieren nur schwach zur angiographischen Ventrikelfunktion. 3. Nur Patienten mit pathologischer Belastungshämodynamik profitieren von der Revaskularisation (definiert als Anstieg der Ejektionsfraktion > 5%). Dieser Profit ist allerdings eng zum Ausmaß der postinfarziellen Ventrikelschädigung korreliert. Folgerungen: Die individuelle Belastbarkeit kann einfach durch die Ergometrie erfaßt werden, die Ventrikelfunktion und damit das Ausmaß der postinfarziellen Ventrikelschädigung werden zuverlässig nichtinvasiv durch die Echokardiographie dargestellt. Die Belastungsuntersuchung mit RHK führt in der Planung der weiteren Strategie für den Postinfarktpatienten (insbesondere in der Frage nach der Notwendigkeit einer Koronarographie und evtl. Revaskularisation) nicht entscheidend weiter und ist u.E. deshalb verzichtbar. In 123 consecutive patients pulmonary hemodynamics at rest and during exercise were measured 7–10 days after acute myocardial infarction and systemic thrombolysis. Right- and left-heart catheterizations were performed at the same session and repeated after 6 months. We investigated if right-heart catheterization could predict the number of stenotic or occluded coronaries, the angiographic ventricular function and/or, most important, if the patient would profit from revascularization by PTCA or coronary surgery. Results: 1) Pulmonary hemodynamics at rest and during exercise did not correlate to the number of stenotic or occluded coronaries, but exercise tolerance did. 2) Correlation between ventricular function and pulmonary hemodynamics was weak. 3) Only patients with pathologically elevated pulmonary pressures at exercise showed profit from revascularization (increase of ejection fraction > 5% at control). This profit was closely correlated to the angiographic extent of ventricular damage. Consequences from our results: Individual exercise tolerance can easily be measured non-invasively. Ventricular function can be measured non-invasively as well as by echocardiography. Measurement of pulmonary hemodynamics at rest and during exercise does not contribute to planning the future management of the postinfarction patient and does not replace coronarography when indicated by clinical or non-invasive parameters.

Heart rate variability for risk stratification after acute myocardial infarction in the thrombolytic era

Investigations involving large populations of post myocardial infarction (MI) patients from the pre-thrombolytic era have demonstrated that a reduced heart rare variability (HRV) is an important factor for the prediction of cardiac mortality. However, little is known whether this prognostic value will persist in an era where thrombolytic therapy and other interventions such as PTCA are available. Therefore, 322 patients of less than 75 years were studied prospectively in a study of consecutively included post MI patients with a total follow-up of 12 months each. Thrombolytic therapy was applied in 69% of the cases. 24-hour ambulatory ECG monitoring included an analysis of arrhythmias and ST segment changes as well as the calculation of 12 HRV parameters in time domain. In addition, the ejection fraction (EF) was determined using radionuclide ventriculography at hospital discharge. Furthermore data from the medical history and the clinical course were recorded. Univariate as well as multivariate analysis revealed an independent prognostic value of HRV parameters from the low frequency range for cardiac mortality in the first year after acute MI. However, the most important factor was older age and an impaired left ventricular function.<<ETX>>