Use of cardiac magnetic resonance imaging in surgical ventricular restoration

Surgical ventricular restoration (SVR) is a promising modality for treatment of heart failure due to left ventricular systolic dysfunction, particularly that due to ischemic heart disease. The role of MRI in improving diagnosis, operative planning, and follow-up is reviewed to analyze how one examination may define a spectrum of important considerations.

Proper patient selection and optimal surgical planning relies on accurate assessment of measures of ventricular volume, function, and viability, and of the mechanics of the mitral valve apparatus. A complete preoperative imaging evaluation includes assessment of the left ventricular volume (both systolic and diastolic), regional and global systolic function, viability of the target area for surgical exclusion and of the remote myocardium, determination of the adequacy of the remote myocardium remaining after proposed SVR to support circulatory function, and of the mitral annular dilatation and inter papillary muscle spacing, factors which contribute to functional mitral regurgitation.

Cardiac magnetic resonance imaging (MRI) allows a complete evaluation of these quantities: the ventricular systolic and diastolic volumes (and hence ejection fraction) are easily assessed reproducibly and accurately; the regional wall motion of the asynergic area and the remote myocardium can be measured by several quantitative means, including with myocardial tagging, and the presence or absence of nonviable, irreversible scar can be detected with gadolinium-based interstitial contrast agents. Furthermore, an accurate measurement of the mitral annular dimensions and the papillary muscle spacing can be easily performed using cardiac MRI, allowing planning of effective therapy for mitral regurgitation.

The entire imaging study can be performed in less than 1h, making cardiac MRI a truly useful and comprehensive tool in planning SVR, and for subsequently evaluating results.