Regional dynamics of fractal dimension of the left ventricular endocardium from cine computed tomography images

We present a method to leverage the high fidelity of CT to quantify regional left ventricular function using topography variation of the endocardium as a surrogate measure of strain. 4DCT images of 10 normal and 10 abnormal subjects, acquired with standard clinical protocols, were used. The topography of the endocardium was characterized by its regional values of fractal dimension (FD), computed using a box-counting algorithm developed in-house. The average FD in each of the 16 American Heart Association segments was calculated for each subject as a function of time over the cardiac cycle. The normal subjects showed a peak systolic percentage change in FD of 5.9% ± 2% in all free-wall segments, while the abnormal cohort experienced a change of 2% ± 1.2% (p < 0.00001). Septal segments, being smooth, did not undergo large changes in FD. Additionally, a principal component analysis was performed on the temporal profiles of FD to highlight the possibility for unsupervised classification of normal and abnormal function. The method developed is free from manual contouring and does not require any feature tracking or registration algorithms. The FD values in the free wall segments correlated well with radial strain and with endocardial regional shortening measurements.

Presence of reduced regional left ventricular function even in the absence of left ventricular wall scar tissue in the long term after repair of an anomalous left coronary artery from the pulmonary artery

BackgroundWe sought to assess left ventricular regional function in patients with and without left ventricular wall scar tissue in the long term after repair of an anomalous origin of the left coronary artery from the pulmonary artery.MethodsA total of 20 patients aged 12.8±7.4 years were assessed 10 (0.5–17) years after the repair of an anomalous origin of the left coronary artery from the pulmonary artery; of them, 10 (50%) patients showed left ventricular wall scar tissue on current cardiac MRI. Left ventricular regional function was assessed by two-dimensional speckle-tracking echocardiography in 10 patients with scar tissue and 10 patients without scar tissue and in 10 age-matched controls.ResultsIn patients with scar tissue, MRI-derived left ventricular ejection fraction was significantly reduced compared with that in patients without scar tissue (51 versus 61%, p<0.05), and echocardiography-derived longitudinal strain was significantly reduced in five of six left ventricular areas compared with that in healthy controls (average relative reduction, 46%; p<0.05). In patients without scar tissue, longitudinal strain was significantly reduced in two of six left ventricular areas (average relative reduction, 23%; p<0.05) and circumferential strain was reduced in one of six left ventricular areas (relative reduction, 56%; p<0.05) compared with that in healthy controls.ConclusionsRegional left ventricular function is reduced even in patients without left ventricular wall scar tissue late after successful repair of an anomalous origin of the left coronary artery from the pulmonary artery. This highlights the need for meticulous lifelong follow-up in all patients with a repaired anomalous origin of the left coronary artery from the pulmonary artery.

New Imaging-Based Tools for the Assessment of Ventricular Function in Ischemic Heart Diseases

Ischemic heart disease morbidity and mortality are closely related to global and regional left ventricular function. The evaluation of left ventricular global function is a relevant part in the evolution of ischemic heart disease because it plays a significant role in prognosis prediction and patient management after revascularization. Regional function is also a critical part of the evolution, offering a possible and reliable mode for the assessment of myocardial disease. Currently several techniques for the evaluation of left ventricular parameters and function are in use. In this review we will discuss and compare currently available methods for the evaluation of global and regional left ventricular function such as 2D and 3D echocardiography, 3D speckle-tracking echocardiography, multi-slice computed tomography, and cardiac magnetic resonance imaging.

Improvements in Regional Left Ventricular Function Following Late Percutaneous Coronary Intervention for Anterior Myocardial Infarction

Background: Late revascularization following a myocardial infarction has questionable clinical benefit. Methods: We studied 13 patients with anterior wall myocardial infarction who underwent percutaneous coronary intervention within 2 weeks of the primary event, by quantitative analysis of 2-dimensional echocardiographic images. Endocardial segmentations of the left ventricular (LV) endocardium from the 4-chamber views were studied over time to establish cumulative wall displacements (CWDs) throughout the cardiac cycle. Results: Left ventricular end-systolic volume decreased to 42 ± 8 mL/body surface area ( P = .034) and LV ejection fraction improved to 52% ± 7% ( P = .04). Analysis of LV endocardial CWD demonstrated significant improvements in mid-systolic to late-systolic phases in the apical LV segments, from 3.5 ± 0.32 to 5.89 ± 0.43 mm ( P = .019). Improvements in CWD were also observed in the late-diastolic phase of the cardiac cycle, from 1.50 ± 0.42 to 1.76 ± 0.52 mm ( P = .04). Conclusions: In our pilot patient cohort, following late establishment of infarct-related artery patency following an anterior wall myocardial infarction, regional improvements were noted in the LV apical segments during systole and late diastole.