| ObjectiveTo date, some essential problems concerning left ventricular surgical reconstruction are still controversial. This study aimed to evaluate the change of left ventricular geometry, wall stress, function and dyssynchrony of non-infarction area after left ventricular reconstruction in patients with postinfarction left ventricular aneurysm. In addition, to compare the geometric and functional results of different techniques:linear repair, endocardial plasty and endocardial patch.MethodsDuring January 2008 to June 2009, a total of 116 selected subjects underwent magnetic resonance imaging,28 healthy volunteers,29 patients with dilated cardiomyopathy and 59 patients with ischemic heart disease (26 left ventricular aneurysm,33 non-left ventricular aneurysm).26 patients with postinfarction ventricular aneurysm underwent left ventricular reconstruction operation. All patients accepted routine preoperative examinations, such as echocardiography, electrocardiogram, X-ray, coronary angiography, left ventricular angiography, and Magnetic resonance imaging (MRI) examination with Seimens Magnetom Avanto 1.5T MR applying routine cine-MRI. Operations were performed on cardiopulmonary bypass. Among them 7 cases were linear repair,12 were endoventricular purse-string suture,7 were endoventricular patch repair, and 25 cases underwent coronary artery bypass graft (CABG) concomitantly. All patients recovered from operation without severe commodities. After operation, MRI examination was rechecked with same sequences. Left ventricular geometric parameters and segmental thickening were obtained with accessory image analysis software. The apical conicity ratio (ACR) was calculated as the ratio of left ventricular apical area over apical triangle. In 16 left ventricular patients, non-invasive blood pressure was acquired in order to compute ventricular wall stress. The revascularized and unrevascularized segments were defined by comparing the revascularization of the blood-supply coronary artery of the certain segment with preoperative coronary angiography results. The postoperative change of segmental wall stress and thickening was tested by paired t test. Tagging sequence was added in 12 left ventricular patients when underwent MRI examination and tagging images were analysis by using HARP software to extract the data and the data were put into calculator software to calculate dyssynchrony index.First, the clinical significant of apical conical ratio was demonstrated, then we compared the geometric and functional results of different techniques:linear repair, endocardial plasty and endocardial patch. Finally, we investigated dyssynchrony of non-infarction area before and after surgical ventricular reconstruction.ResultsIn dilated cardiomyopathy patients, sphericity index and eccentricity index increased significantly without apical conicity ratio changes. Among ischemic heart disease patients, apical conicity ratio of left ventricular aneurysm group was significantly higher than that of non-left ventricular aneurysm group when the other indices between the two groups showed no statistically difference. Receiver operating character curves showed only apical conicity ratio had high power of discriminating left ventricular aneurysm from non-left ventricular aneurysm. All of techniques:linear repair, endocardial plasty and endocardial patch decreased the left ventricular volume and increased systolic function. Compared with other two techniques, endocardial plasty technique achieved better left ventricular shape and function. The perioperative segmental thickening and stress were presented below. After operation, segmental thickening improving and wall stress decreasing in both unrevascularized and revascularized segments were observed and the correlation of them was apparent. After operation, left ventricular ejection fraction improved and indexed left ventricular end-systolic volume decreased significantly. However, left ventricular dyssynchrony index of non-infarction area remained.ConclusionsThe new index, apical conicity ratio, can be used to quantify the regional left ventricular deformation, especially in patients with myocardial infarcted left ventricular aneurysm. Left ventricular reconstruction can decrease ventricular wall stress and improve myocardial contractive function. Among those three techniques, endocardial plasty can achieve better left ventricular geometry and function. Surgical ventricular restoration resulted in improvement of left ventricular ejection fraction, significant left ventricular volume reduction. However, left ventricular synchrony index of non-infarction area remained.
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