Naslov
The impact of acute pressure overload on regional changes in the timing of myocardial contraction. Insight from a closed chest, closed pericardium animal model.

Autori
Čikeš, Maja ; Jakuš, Nina ; Sutherland, George ; Haemers, Peter ; D'Hooge, Jan ; Claus, Piet.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
European Heart Journal / - , 2013

Skup
ESC Congress 2013

Mjesto i datum
Amsterdam, Nizozemska, 31.08.2013. - 04.09.2013

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Acute afterloading; pressure surge; animal model; echocardiography; LV contraction

Sažetak
Purpose: Most interventional studies providing insight to left ventricular (LV) mechanics during afterload increase have been performed on open chest/pericardium animals. However, little is known about the impact of acute afterload on LV wall contraction timing in the setting of a more physiological, closed chest, closed pericardium model. Thus, we aimed to study the impact of acute LV pressure overload on the timing of regional myocardial contraction in such a model. Methods: 7 anesthetised, closed chest/closed pericardium pigs were instrumented with a balloon positioned in the descending aorta, partially inflated during 5-10 heartbeats creating an approx. 30% LV pressure increase. Echocardiographic LV LAX B-mode cine-loops were acquired in cine-loops including 5 preinflation and 5-10 inflation beats. Anatomic M-mode images of the LV base and apex were created and the time from Q wave on the simultaneous ECG trace to end- systolic (ES) septal and posterior wall thickening was measured. Results: At baseline, septal ES thickening occurred sooner at the apex (309.7±47.8 ms) than at the LV base (362.6±47.4 ms, p<0.01) in all pigs (Figure 1). Conversely, during acute afterload, the septal thickening was the earliest at the LV base (299.6±99.7 vs. 387.3±90 ms for apex, p=0.01). The same timing pattern was noted at the posterior wall (baseline: apex 364.3±45 vs base 392±31.5 ms, p=0.05 ; inflation: apex 415.1±45.7 vs base 353.9±87.8 ms, p=0.01). Conclusions: The study demonstrates the inversion of regional timing of LV wall contraction during acute afterload increase such that with loading LV contraction commences at the base and is the latest at the apex. This might provide further insight to electromechanical wave propagation and its potential relation to reflected waves in pressure overload.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

POVEZANOST RADA