News
Dec 9, 2016

CCI at AHA Scientific Sessions


 

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AHA Scientific Sessions took place in mid-November in New Orleans, Louisiana, USA. Several center members participated and presented the most recent results of their research. Read the program here.

Some of the highlights include results showing that strain by FTMRI in combination with noninvasive LV pressure demonstrates marked asymmetry in distribution of segmental work in patients with LBBB, and that mechanical dispersion by speckle tracking echocardiography is associated with adverse outcome in conservatively treated patients with aortic stenosis independently of left ventricular ejection fraction and age.

Category: General
Posted by: Piritta

Center director professor Thor Edvardsen had an invited lecture titled "Myocardial strain imaging in hypertrophic cardiomyopathy" under the session for Myocardial Strain Imaging. Inherited hypertrophic cardiomyopathy (HCM) is often benign with few symptoms and normal life expectancy, but some patients suffer from sudden cardiac death as the first manifestation of the disease. Left ventricular ejection fraction (LVEF) might be normal or even supernormal in HCM patients with severely depressed longitudinal systolic function. Global longitudinal strain by speckle tracking echocardiography is related to myocardial thickness, scar and arrhythmias, and adds important information to LVEF on ventricular function in these patients.

Klæboe LG, Leren IS, ter Bekke RM, Røsjø H, Omland T, Gullestad L, Haugaa KH, Edvardsen T
Altered myocardial mechanics have prognostic value in conservatively treated patients with aortic stenosis

In aortic stenosis clinical exacerbation is fast after onset of symptoms. Impairment of left ventricular ejection fraction is a late occurring phenomenon in the disease process, but early alterations of left ventricular function is detectable by strain echocardiography. Our main finding was that mechanical dispersion by speckle tracking echocardiography was associated with adverse outcome in conservatively treated patients with aortic stenosis independently of left ventricular ejection fraction and age.

Remme EW, Simseth OA
Impaired Subendocardial Contractility and Longitudinal Shortening with Aging, Reduce Midwall Fiber Stress, Increasing Circumferential Shortening and Preserving Ejection Fraction

The poster, presented by senior scientist Espen Remme, was a theoretical study using a mathematical finite element model where subendocardial contractility could be selectively adjusted. The model was used to investigate reduced subendocardial contractility’s effects on and the interaction between longitudinal and circumferential strains and fiber stresses.

Larsen CK, Aalen J, Stokk C, Fjeld JG, Kongsgaard E, Smiseth OA, Hopp E
Regional Myocardial Work by Magnetic Resonance Imaging and Noninvasive Left Ventricular Pressure: A Feasibility Study in Left Bundle Branch Block

We aimed to determine if regional myocardial work can be measured clinically by MRI and noninvasive LV pressure, and to test the feasibility of this approach in left bundle branch block (LBBB).
Regional work was estimated according to the principle of Russell et al., which is based upon an estimated LV pressure curve in combination with strain. The durations of the different cardiac phases were measured by valvular event timing, and the normalized standard LVP curve was adjusted according to the measured phase durations. The amplitude of the estimated LV pressure curve was scaled by the patient’s systolic brachial cuff pressure, which was used a substitute for peak LVP.

By definition, work during myocardial shortening is positive and work during lengthening is negative. Net work is the sum of positive and negative work. We concluded that strain by FTMRI in combination with noninvasive LV pressure demonstrated marked asymmetry in distribution of segmental work in patients with LBBB. Work distribution corresponded well with regional glucose metabolism. These results imply that strain by FTMRI in combination with non-invasive LV pressure is feasible as a clinical tool to measure regional myocardial work.

McLeod K, Wall S, Leren IS, Saberniak J, Haugaa KH
Ventricular shape correlates to arrhythmic events in ARVC patients

Kristin McLeod presented two posters for the CCI at this year’s American Heart Association Scientific Sessions at New Orleans. The first poster showed that ventricular shape, when quantified in 3D and used in conjunction with volumes and ejection fraction, could be potential predictors of ventricular arrhythmias in patients with Arrhythmogenic Right Ventricular Cardiomyopathy. The second study was an investigation into ventricular shape in adolescent patients with arterial switch operated Transposition of the Great Arteries, for which the authors found that despite being asymptomatic and have seemingly normal anatomy via visual analysis of CMR images, these patients undergo ventricular remodelling which could suggest the need for further intervention later in life.

Heart SFI