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Left ventricular geometry immediately following defibrillation: shock-induced relaxation.

Publication ,  Journal Article
De Jongh, AL; Ramanathan, V; Hoffmeister, BK; Malkin, RA
Published in: American journal of physiology. Heart and circulatory physiology
March 2003

A previous two-dimensional (2D) ultrasound study suggested that there is relaxation of the myocardium after defibrillation. The 2D study could not measure activity occurring within the first 33 ms after the shock, a period that may be critical for discriminating between shock- and excitation-induced relaxation. The objective of our study was to determine the left ventricular (LV) geometry during the first 33 ms after defibrillation. Biphasic defibrillation shocks were delivered 5-50 s after the induction of ventricular fibrillation in each of the seven dogs. One-dimensional, short-axis ultrasound images of the LV cavity were acquired at a rate of 250 samples/s. The LV cavity diameter was computed from 32 ms before to 32 ms after the shock. Preshock and postshock percent changes in LV diameter were analyzed as a function of time with the use of regression analysis. The normalized mean pre- and postshock slopes (0.2 +/- 2.2 and 3.3 +/- 7.9% per 10 ms) were significantly different (P < 0.01). The postshock slope was positive (P < 0.005). Our results confirm that the bulk of the myocardium is relaxing immediately after defibrillation.

Duke Scholars

Published In

American journal of physiology. Heart and circulatory physiology

DOI

EISSN

1522-1539

ISSN

0363-6135

Publication Date

March 2003

Volume

284

Issue

3

Start / End Page

H815 / H819

Related Subject Headings

  • Ventricular Fibrillation
  • Time Factors
  • Heart Ventricles
  • Electrophysiologic Techniques, Cardiac
  • Electrocardiography
  • Electric Countershock
  • Echocardiography
  • Dogs
  • Cardiovascular System & Hematology
  • Cardiac Volume
 

Citation

APA
Chicago
ICMJE
MLA
NLM
De Jongh, A. L., Ramanathan, V., Hoffmeister, B. K., & Malkin, R. A. (2003). Left ventricular geometry immediately following defibrillation: shock-induced relaxation. American Journal of Physiology. Heart and Circulatory Physiology, 284(3), H815–H819. https://doi.org/10.1152/ajpheart.00093.2002
De Jongh, Amy L., Vijaya Ramanathan, Brent K. Hoffmeister, and Robert A. Malkin. “Left ventricular geometry immediately following defibrillation: shock-induced relaxation.American Journal of Physiology. Heart and Circulatory Physiology 284, no. 3 (March 2003): H815–19. https://doi.org/10.1152/ajpheart.00093.2002.
De Jongh AL, Ramanathan V, Hoffmeister BK, Malkin RA. Left ventricular geometry immediately following defibrillation: shock-induced relaxation. American journal of physiology Heart and circulatory physiology. 2003 Mar;284(3):H815–9.
De Jongh, Amy L., et al. “Left ventricular geometry immediately following defibrillation: shock-induced relaxation.American Journal of Physiology. Heart and Circulatory Physiology, vol. 284, no. 3, Mar. 2003, pp. H815–19. Epmc, doi:10.1152/ajpheart.00093.2002.
De Jongh AL, Ramanathan V, Hoffmeister BK, Malkin RA. Left ventricular geometry immediately following defibrillation: shock-induced relaxation. American journal of physiology Heart and circulatory physiology. 2003 Mar;284(3):H815–H819.

Published In

American journal of physiology. Heart and circulatory physiology

DOI

EISSN

1522-1539

ISSN

0363-6135

Publication Date

March 2003

Volume

284

Issue

3

Start / End Page

H815 / H819

Related Subject Headings

  • Ventricular Fibrillation
  • Time Factors
  • Heart Ventricles
  • Electrophysiologic Techniques, Cardiac
  • Electrocardiography
  • Electric Countershock
  • Echocardiography
  • Dogs
  • Cardiovascular System & Hematology
  • Cardiac Volume