Passive ventricular constraint amends the course of heart failure: a study in an ovine model of dilated cardiomyopathy

Abstract

In this model of heart failure, ventricular constraint with a polyester jacket diminished the deterioration in cardiac function associated with progressive dilated cardiomyopathy. These results suggest that maintainance of a more normal cardiac size and shape may be beneficial in patients with dilated cardiomyopathy.

Adjustable, Physiological Ventricular Restraint Improves Left Ventricular Mechanics and Reduces Dilatation in an Ovine Model of Chronic Heart Failure

“…[1][2][3][4][5][6][7][8]20,21 To date, no study has evaluated LV mechanics in restraint or the effect of adjustable restraint. Current ventricular restraint techniques, such as the Acorn Cardiac Support Device (Acorn Cardiovascular, St. Paul, Minn) and the Paracor (Paracor Medical Systems, Sunnyvale, Calif), do not allow for either the quantitative adjustment of restraint level or the measurement of P tm .…”

“…Current ventricular restraint techniques, such as the Acorn Cardiac Support Device (Acorn Cardiovascular, St. Paul, Minn) and the Paracor (Paracor Medical Systems, Sunnyvale, Calif), do not allow for either the quantitative adjustment of restraint level or the measurement of P tm . 3,10 A standard for wrap tightness does not exist. Surgeons are instructed to apply the Acorn Cardiac Support Device in such a way that it fits not too loosely and not too tightly, but "snugly."…”

“…Numerous studies have demonstrated that passive ventricular restraint may prevent or reverse left ventricular (LV) dilation and remodeling in HF. [3][4][5][6][7][8] The precise mechanics of this, however, are not known. Our hypothesis is that ventricular restraint decreases transmural myocardial pressure (P tm ) by pressure application on the epicardium at end diastole.…”

Passive Ventricular Constraint Prevents Transmural Shear Strain Progression in Left Ventricle Remodeling

“…A CSD has been shown to halt progressive LV dilation and improve ejection fraction. [17][18][19][20][21][22][23][24] Although multiple laboratory and clinical studies have been performed to examine the possible mechanisms of CSD on LV remodeling, its effects on regional 3D myocardial transmural strain adjacent to and remote from an infarct are unknown. This study was designed to test the hypothesis that placement of passive external cardiac constraint would decrease postinfarction LV dilatation and sphericalization and prevent abnormal transmural LV wall shear strains.…”

Preservation of Cardiac Extracellular Matrix by Passive Myocardial Restraint

“…This device, called the CorCap Cardiac Support Device (CSD), is made from a polyester fabric mesh (ACORN Cardiovascular) and is surgically placed around the heart to provide passive diastolic circumferential restraint. 11 Surgical implantation of this device in several different animal models has been shown to attenuate ventricular dilation, reduce mitral regurgitation, and improve overall ventricular pump function without causing pathological diastolic restriction. [12][13][14][15] Preliminary nonrandomized studies of CSD placement with or without concomitant coronary bypass or mitral valve surgery in patients with moderate to severe heart failure have produced encouraging results in as far as improvements in ventricular size, shape, function, and hemodynamics are concerned without raising concerns about significant side effects.…”