Public Defence: Lars Gunnar Klæboe Lars Gunnar Klæboe at Institute of Clinical Medicine will be defending the thesis “Strain imaging in aortic stenosis” for the degree of PhD (Philosophiae Doctor).

Photo: Maren Leifson

Trial Lecture – time and place

See Trial Lecture.

Adjudication committee

  • First opponent: Professor Jacob Eifer Møller, Odense University Hospital, Denmark
  • Second opponent: Professor Mai Tone Lønnebakken, University of Bergen
  • Third member and chair of the evaluation committee: Professor II Arnt Fiane, University of Oslo

Chair of the Defence

Professor II Johny Kongerud, Faculty of Medicine, University of Oslo

Principal Supervisor

 Professor II Thor Edvardsen, Faculty of Medicine, University of Oslo


Aortic stenosis is a prevalent valvular disease with progressive obstruction of blood flow across the orifice of the aortic valve leading to gradual impairment of myocardial function. Conventional cardiac ultrasound (echocardiography) often recognizes altered myocardial function in later stages of aortic stenosis. Speckle tracking echocardiography (STE) allows earlier identification of myocardial dysfunction through accurate and sensitive assessment of myocardial performance but has not been fully explored in aortic stenosis. Transcatheter aortic valve implantation (TAVI) causes abrupt hemodynamic changes, but is frequently complicated by left bundle branch block, providing an opportunity to evaluate whether changes in afterload and ventricular conduction affect parameters from STE.

Using STE, we observed prognostically relevant myocardial dysfunction and dyssynchrony in patients with severe aortic stenosis undergoing open heart surgery, TAVI, or receiving medical treatment. Subtle abnormalities of myocardial function were associated with increased mortality both after TAVI and open surgery. Myocardial dyssynchrony improved after TAVI in patients with unchanged ventricular conduction. TAVI-induced left bundle branch block did not have the typical dyssynchronous activation pattern associated with significant electrical delay, but rather more homogeneous contractions. Overall, our observations provide new insights regarding dyssynchrony, STE and cardiac function in aortic stenosis.

Additional information

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Published Dec. 5, 2019 5:00 PM - Last modified Dec. 5, 2019 5:03 PM