Claus Graff

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Digital stethoscopes offer new opportunities for computerized analysis of heart sounds. Segmentation of heart sound recordings into periods related to the first and second heart sound (S1 and S2) is fundamental in the analysis process. However, segmentation of heart sounds recorded with handheld stethoscopes in clinical environments is often complicated by(More)
The long QT syndrome (LQTS) is a genetic disorder, typically characterized by a prolonged QT interval in the ECG due to abnormal cardiac repolarization. LQTS may lead to syncopal episodes and sudden cardiac death. Various parameters based on T-wave morphology, as well as the QT interval itself have been shown to be useful discriminators, but no single ECG(More)
BACKGROUND We sought to perform a study assessing the association between electrocardiographic ST-segment deviations and cardiovascular death (CVD), in relation to sex and age (≥ and <65 years), in a large primary care population without overt ischemic heart disease. METHODS AND RESULTS Using computerized analysis of ECGs from 285 194 persons, we(More)
OBJECTIVE Recent research suggests that other surrogate markers than QTc, including QTc dispersion and Tpeak-Tend, may better correlate with cardiac arrhythmia risk. While sertindole significantly prolongs the QTc interval, the effects on other markers of arrhythmia risk, such as QTc dispersion and Tpeak-Tend are unknown. METHOD Digital 12-lead ECG was(More)
Certain antipsychotics increase the risk of heart rate-corrected QT (QTc) prolongation and consequently Torsades de Pointes (TdP) and sudden cardiac death (SCD). Drug-induced Brugada syndrome (BrS) is also associated with SCD. Most SCDs occur in patients with additional cardiac risk factors. Aripiprazole’s cardiac safety has not been assessed in patients at(More)
Various parameters based on QTc and T-wave morphology have been shown to be useful discriminators for drug induced I(Kr)-blocking. Using different classification methods this study compares the potential of these two features for identifying abnormal repolarization on the ECG. A group of healthy volunteers and LQT2 carriers were used to train classification(More)
Sertindole's propensity to prolong the QT interval relates to blockade of the KCNH2 (HERG) encoded Ikr potassium channel, but there has been limited detailed data on T-wave morphology changes. Digital 12-lead ECG was recorded at baseline and at steady-state in 37 patients switched to sertindole. ECG was analyzed for quantitative T-wave morphology changes(More)
A noninvasive method for detection of coronary artery disease (CAD) with an electronic stethoscope is proposed. Heart sounds recorded in clinical settings are often contaminated with background noise and noise caused by friction between the skin and the stethoscope. A method was developed to reduce the influence of the noise artifacts. The diastolic parts(More)
AIMS Using a large, contemporary primary care population we aimed to provide absolute long-term risks of cardiovascular death (CVD) based on the QTc interval and to test whether the QTc interval is of value in risk prediction of CVD on an individual level. METHODS AND RESULTS Digital electrocardiograms from 173 529 primary care patients aged 50-90 years(More)
Digital stethoscopes offer new opportunities for computerized analysis of heart sounds. Segmentation of hearts sounds is a fundamental step in the analyzing process. However segmentation of heart sounds recorded with handheld stethoscopes in clinical environments is often complicated by recording and background noise. A Duration-dependent Hidden Markov(More)