Strukturierter Datensatz zur Befunddokumentation in der Echokardiographie?Version 2004

Avoiding implantation of a cardioverter-defibrillator by bridging with wearable defibrillator vest

BACKGROUND

Patients with a left ventricular ejection fraction (LVEF) ≤35% should be protected from sudden cardiac death with an implantable cardioverter-defibrillator (ICD). The onset of the effect of optimal medical therapy (OMT) is unclear, and a wearable cardioverter-defibrillator (WCD) can bridge this period.

PATIENTS AND METHODS

Our study analyzed 104 patients (age, 68.9 ± 11.7 years; 81% [84/104] male) whose first diagnosis included an LVEF <35%. After exclusion of reversible causes for LVEF reduction and initiation/adjustment of the OMT, the WCD was employed. The LVEF and indication for ICD were re-evaluated after 62 ± 36 days. The LVEF development and implantation rate were correlated with underlying disease (ischemic [ICM] or nonischemic cardiomyopathy [NICM]), comorbidities, and age/gender.

RESULTS

The wearing time of the WCD was 22.8 ± 1.9 h/day. An LVEF improvement from 28.5 ± 6.4% to 40 ± 11.7% was achieved through OMT (p < 0.0001). An improvement in LVEF of up to more than 35% was achieved in 66 of 104 patients (63%), and only 37% of patients were subsequently given an ICD. This affected 41% of patients with ICM and 30% of patients with NICM (p = 0.205). Notably, no ICD interventions were observed over 362 ± 89.5 days after implantation in the ICD-receiver group.

CONCLUSION

The indication for ICD can be re-evaluated after 2 months. Patients with NICM respond better to OMT compared with ICM patients. The LVEF recovered to >35% in >60% of cases.

Fine-grained information extraction from German transthoracic echocardiography reports

Background

Information extraction techniques that get structured representations out of unstructured data make a large amount of clinically relevant information about patients accessible for semantic applications. These methods typically rely on standardized terminologies that guide this process. Many languages and clinical domains, however, lack appropriate resources and tools, as well as evaluations of their applications, especially if detailed conceptualizations of the domain are required. For instance, German transthoracic echocardiography reports have not been targeted sufficiently before, despite of their importance for clinical trials. This work therefore aimed at development and evaluation of an information extraction component with a fine-grained terminology that enables to recognize almost all relevant information stated in German transthoracic echocardiography reports at the University Hospital of Würzburg.

Methods

A domain expert validated and iteratively refined an automatically inferred base terminology. The terminology was used by an ontology-driven information extraction system that outputs attribute value pairs. The final component has been mapped to the central elements of a standardized terminology, and it has been evaluated according to documents with different layouts.

Results

The final system achieved state-of-the-art precision (micro average.996) and recall (micro average.961) on 100 test documents that represent more than 90 % of all reports. In particular, principal aspects as defined in a standardized external terminology were recognized with f₁=.989 (micro average) and f₁=.963 (macro average). As a result of keyword matching and restraint concept extraction, the system obtained high precision also on unstructured or exceptionally short documents, and documents with uncommon layout.

Conclusions

The developed terminology and the proposed information extraction system allow to extract fine-grained information from German semi-structured transthoracic echocardiography reports with very high precision and high recall on the majority of documents at the University Hospital of Würzburg. Extracted results populate a clinical data warehouse which supports clinical research.

Electronic supplementary material

The online version of this article (doi:10.1186/s12911-015-0215-x) contains supplementary material, which is available to authorized users.

Effects of auto-servo ventilation on patients with sleep-disordered breathing, stable systolic heart failure and concomitant diastolic dysfunction: subanalysis of a randomized controlled trial

BACKGROUND

Systolic heart failure (HF) is frequently accompanied by diastolic dysfunction and sleep-disordered breathing (SDB).

OBJECTIVES

The objective of this subset analysis was to determine effect sizes of auto-servo ventilation (ASV and biphasic positive airway pressure ASV) on echocardiographic measures of diastolic function in patients with systolic HF and SDB.

METHODS

Thirty-two patients with stable systolic HF, concomitant diastolic dysfunction [age 66 ± 9 years old, left ventricular (LV) ejection fraction: 30 ± 7% and New York Heart Association class II: 72%] and SDB (apnea-hypopnea index, AHI: 48 ± 19/h; 53% had predominantly obstructive sleep apnea) receiving either ASV (n = 19) or optimal medical treatment (control, n = 13) were analyzed in a randomized controlled clinical trial. Polysomnographic and echocardiographic measurements were obtained at baseline and after 12 weeks.

RESULTS

AHI significantly improved in the ASV group compared to the control group (-39 ± 18 vs. -0.2 ± 13.2/h, p < 0.001). At baseline, 24 (75%) patients had impaired LV relaxation, and 8 (25%) had a pseudo-normalized filling pattern. At the 12-week control visit, diastolic function assessed by the isovolumetric relaxation time (-10.3 ± 26.1 vs. 9.3 ± 49.1, p = 0.48) and deceleration time (-43.9 ± 88.8 vs. 12.4 ± 68.8, p = 0.40) tended to improve after ASV treatment, but did not reach statistical significance. Likewise, the proportion of patients whose diastolic dysfunction improved was nonsignificantly higher in the ASV than in the control group, respectively (37 vs. 15%, p = 0.25).

CONCLUSIONS

ASV treatment efficiently abolishes SDB in patients with stable systolic HF and concomitant diastolic dysfunction, and was associated with a statistically nonsignificant improvement in measures of diastolic dysfunction. Thus, these data provide estimates of effect size and justify the evaluation of the effects of ASV on diastolic function in larger randomized controlled trials.

Do induced tachycardias within the scope of electrophysiological studies lead to elevated plasma troponin I levels?

AIMS

Troponin I (TNI) is an established marker for the diagnosis of acute coronary syndrome (ACS). The study evaluated if (induced) tachycardiac arrhyhthmias within the scope of the electrophysiological studies (EPS) led to elevation of TNI serum levels.

METHOD

TNI was measured in the serum of 28 patients before and after the EPS. The left ventricular ejection fraction (LV-EF) was investigated by two-dimensional echocardiography. Left ventricle hypertrophy (LVH) was measured according to the recommendations of the American Society of Echocardiography. All patients underwent coronary angiography prior to the EPS, and significant coronary heart disease was defined as stenosis > 50%. The EPS revealed supraventricular and ventricular tachycardias using the 18-step protocol with one, two, and three extrastimuli.

RESULTS

Indications for the EPS were syncope (n = 15), atrioventricular tachycardia (n = 4), non-sustained VT (n = 6), and sustained VT (n = 3). Coronary heart disease (CHD) was detected in 8 patients (1-vessel: n = 3; 2-vessel: n = 4; 3-vessel: n = 1), and 2 patients underwent percutaneous coronary intervention before EPS. Echocardiography revealed normal LV-EF in 18 patients and a reduction in the others (low n = 3, middle n = 5, high n = 2). Thirteen patients suffered from LVH. In 2 patients, external cardioversion was required during the EPS. TNI was elevated over 0.1 ng/ml (risk stratification cut-off for ACS) in 4 patients before and in 12 patients after EPS. There was no relationship between LV-EF, CHD, and the elevation of TNI after the EPS.

CONCLUSION

TNI can be elevated by (induced) tachycardias within the scope of electrophysiological studies without a relationship to LV-EF, LVH, and CHD.

Echokardiographische Funktionsdiagnostik bei Patienten mit rheumatoider Arthritis und Kollagenosen

Cardiac manifestations were observed in patients with rheumatoid arthritis and other collagenoses. Echocardiography is a method of choice to detect pathologies in morphology and function of the heart. Pathophysiologically inflammatory alterations of the endo- as well as perimyocardium can be explained in these patients. In addition, in patients with collagenoses, the coagulation system is activated and the reactivity of the endothelium is reduced. Thus, thrombus formation at the heart valves with consecutive stenosis and/or regurgitations as well as ischemia-induced regional wall motion defects due to reduced vasodilator response of the coronary arteries can be expected. In the literature in patients with rheumatoid arthritis and other collagenoses, pericardial effusion and pulmonary hypertension are most frequently described. The echocardiographic analysis, however, is more complex due to the variability of the patient cohort. Quantification of valve defects and the analysis of wall motion and perfusion at rest and during stress is necessary to detect early changes of the diseases. The prerequisites for successful diagnostic echocardiography in these patients are the knowledge of modern echocardiographic techniques like tissue Doppler and contrast echocardiography and clinical experience with patients with rheumatoid arthritis and other collagenoses. The standardization of the echocardiographic diagnostic procedure becomes more and more important for reproducibility and comparability of the results.