J Kraatz

Universität Heidelberg, Heidelburg, Baden-Württemberg, Germany

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Publications (3)3.69 Total impact

  • R Elfner, J Buss, J Kraatz, D L Heene
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    ABSTRACT: We compared the annotation of the AHA and MIT databases beat-to-beat with the classification preformed by the microprocessor of a 24-hour ambulatory electrocardiographic device, based on real-time analysis. Sensitivity and positive predictive accuracy for QRS detection were 99.9% (99.9%) and 99.9% (99.8%) for the AHA database (MIT database respectively). Sensitivity and positive predictive accuracy were 99.1% (96.6%) and 98.3% (94.9%) for ventricular ectopic beats, 98.3% (91.8%) and 96.0% (63.0%) for couplets and 96.4% (74.2%) and 99.2% (41.1%) for salvoes. On 90% of the AHA tapes (MIT tapes) sensitivity and positive predictive accuracy were at least 93.8% (76.6%) and 92.7% (65.5%) for ventricular ectopic beats, at least 98.0% (96.3%) and 54.5% (0%) for couplets and at least 100% (66.6%) and 100% (0%) for salvoes. A sensitivity of 100% was achieved for ventricular ectopic beats on 56% (45%), for couplets on 90% (82%) and for salvoes on 95% (84%) of the AHA tapes (MIT tapes). A positive predictive accuracy of 100% was achieved for ventricular ectopic beats on 49% (52%), for couplets on 76% (61%) and for salvoes on 97% (75%) of the AHA tapes (MIT tapes). Real-time analysis of the Oxford Medilog 4500 proved sufficient for QRS detection and classification of ventricular ectopic beats. The quantification of frequent couplets and salvoes was sufficient, too. Sporadic false-positive detections of complex ventricular ectopic beats produced the false Lown grade IVA/IVB on 10% of the tapes as a consequence. The final computer report must hence be edited by a physician.
    Zeitschrift für Kardiologie 09/1987; 76(8):492-500. · 0.97 Impact Factor
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    ABSTRACT: Noninvasive recordings in a 69-year-old woman showed two distinct PR intervals of about 0.21 and 0.58 s, suggestive of dual AV nodal conduction. Various unusual mechanisms of transition from short to long and from long to short conduction intervals and phenomena of concealed conduction were due to the presence of two functionally separated intranodal pathways. Refractoriness of the slow pathway was associated with bradycardia. Episodes of tachycardia exhibited a one-to-two relationship between P-waves and ventricular activations as a consequence of simultaneous anterograde fast and slow conduction leading to double ventricular responses to single P-waves.
    Pacing and Clinical Electrophysiology 04/1985; 8(2):235-41. · 1.75 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Noninvasive recordings in a 69-year-old woman showed phasic shifts between two distinct PR intervals of about 0.21 and 0.58 s suggestive of dual AV nodal conduction in the presence of two intranodal pathways. Episodes of tachycardia exhibited a one to two relationship between P waves and QRS complexes, with the same short and long PR intervals interpreted as simultaneous anterograde fast and slow conduction via the two AV nodal pathways, leading to a double ventricular response to single P waves. Various mechanisms of transition from short to long or long to short conduction times and concealed conduction phenomena could be demonstrated supporting the concept of two functionally separated intranodal pathways.
    Zeitschrift für Kardiologie 04/1985; 74(3):180-4. · 0.97 Impact Factor

Publication Stats

16 Citations
3.69 Total Impact Points

Institutions

  • 1985–1987
    • Universität Heidelberg
      • I. Medical Clinic
      Heidelburg, Baden-Württemberg, Germany