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Animal models of dyssynchrony.

Strik M, van Middendorp LB, Vernooy K - J Cardiovasc Transl Res (2011)

Bottom Line: Cardiac resynchronization therapy (CRT) is an important therapy for patients with heart failure and conduction pathology, but the benefits are heterogeneous between patients and approximately a third of patients do not show signs of clinical or echocardiographic response.This calls for a better understanding of the underlying conduction disease and resynchronization.In this review, we discuss to what extent established and novel animal models can help to better understand the pathophysiology of dyssynchrony and the benefits of CRT.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. m.strik@maastrichtuniversity.nl

ABSTRACT
Cardiac resynchronization therapy (CRT) is an important therapy for patients with heart failure and conduction pathology, but the benefits are heterogeneous between patients and approximately a third of patients do not show signs of clinical or echocardiographic response. This calls for a better understanding of the underlying conduction disease and resynchronization. In this review, we discuss to what extent established and novel animal models can help to better understand the pathophysiology of dyssynchrony and the benefits of CRT.

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Typical examples of 3D electrical activation in canine hearts during normal conduction (left panel) and after creation of LBBB (right panel). Plotted activation times were derived from ≈110 epicardial and endocardial contact electrodes and referenced to the onset of the Q wave. In the right panel, the ablation catheter is shown with the approximate location of ablation after which a LBBB pattern occurred
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Fig2: Typical examples of 3D electrical activation in canine hearts during normal conduction (left panel) and after creation of LBBB (right panel). Plotted activation times were derived from ≈110 epicardial and endocardial contact electrodes and referenced to the onset of the Q wave. In the right panel, the ablation catheter is shown with the approximate location of ablation after which a LBBB pattern occurred

Mentions: To investigate the effects of LBBB and CRT, a LBBB model was developed in canine hearts [11–13]. Through the aortic valve, an ablation catheter is positioned against the basal septum. Guided by the local endocardial electrogram derived from the tip of the catheter, the left bundle branch is located as evidenced by a sharp deflection between A-wave and V-wave and subsequently ablated (Fig. 1) [13]. Electrical mapping during dyssynchronous activation is discussed more extensively elsewhere in this edition. In short, in the healthy canine heart electrical activation is very synchronous but ablation of the proximal left bundle branch causes a severe delay in the electrical activation of the LV postero-lateral wall (Fig. 2). As shown in Fig. 3, the morphology and duration of the QRS complex change and in agreement to the observations of Wiggers, dyssynchronous contraction causes reduction in ejection time and slows rates of rise and fall of LV and aortic pressure and increases duration of isovolumic contraction and relaxation [14, 15]. For animated echocardiographic short-axis LV examples of normal conduction and left bundle branch block, see Online Resource 1 and 2.Fig. 1


Animal models of dyssynchrony.

Strik M, van Middendorp LB, Vernooy K - J Cardiovasc Transl Res (2011)

Typical examples of 3D electrical activation in canine hearts during normal conduction (left panel) and after creation of LBBB (right panel). Plotted activation times were derived from ≈110 epicardial and endocardial contact electrodes and referenced to the onset of the Q wave. In the right panel, the ablation catheter is shown with the approximate location of ablation after which a LBBB pattern occurred
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3306020&req=5

Fig2: Typical examples of 3D electrical activation in canine hearts during normal conduction (left panel) and after creation of LBBB (right panel). Plotted activation times were derived from ≈110 epicardial and endocardial contact electrodes and referenced to the onset of the Q wave. In the right panel, the ablation catheter is shown with the approximate location of ablation after which a LBBB pattern occurred
Mentions: To investigate the effects of LBBB and CRT, a LBBB model was developed in canine hearts [11–13]. Through the aortic valve, an ablation catheter is positioned against the basal septum. Guided by the local endocardial electrogram derived from the tip of the catheter, the left bundle branch is located as evidenced by a sharp deflection between A-wave and V-wave and subsequently ablated (Fig. 1) [13]. Electrical mapping during dyssynchronous activation is discussed more extensively elsewhere in this edition. In short, in the healthy canine heart electrical activation is very synchronous but ablation of the proximal left bundle branch causes a severe delay in the electrical activation of the LV postero-lateral wall (Fig. 2). As shown in Fig. 3, the morphology and duration of the QRS complex change and in agreement to the observations of Wiggers, dyssynchronous contraction causes reduction in ejection time and slows rates of rise and fall of LV and aortic pressure and increases duration of isovolumic contraction and relaxation [14, 15]. For animated echocardiographic short-axis LV examples of normal conduction and left bundle branch block, see Online Resource 1 and 2.Fig. 1

Bottom Line: Cardiac resynchronization therapy (CRT) is an important therapy for patients with heart failure and conduction pathology, but the benefits are heterogeneous between patients and approximately a third of patients do not show signs of clinical or echocardiographic response.This calls for a better understanding of the underlying conduction disease and resynchronization.In this review, we discuss to what extent established and novel animal models can help to better understand the pathophysiology of dyssynchrony and the benefits of CRT.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. m.strik@maastrichtuniversity.nl

ABSTRACT
Cardiac resynchronization therapy (CRT) is an important therapy for patients with heart failure and conduction pathology, but the benefits are heterogeneous between patients and approximately a third of patients do not show signs of clinical or echocardiographic response. This calls for a better understanding of the underlying conduction disease and resynchronization. In this review, we discuss to what extent established and novel animal models can help to better understand the pathophysiology of dyssynchrony and the benefits of CRT.

Show MeSH
Related in: MedlinePlus