Cardiac magnetic resonance assessment of diastolic dysfunction in acute coronary syndrome

Clinical research progress of myocardial work in assessment and prediction of coronary artery disease in noninvasive pressure-strain loop technique

Early identification and treatment of high-risk coronary artery disease (CAD) is the main goal of current cardiovascular disease treatments. Speckle-tracking ultrasound technology can quantify myocardial work using pressure-strain loops. Because myocardial work takes into account the effect of the left ventricular systolic function afterload, it can more objectively reflect left ventricular myocardial mechanical function than the overall left ventricular longitudinal strain. Therefore, this technique is more widely used in diseases caused by CAD. This article reviews the evaluation and prediction of different CAD types using a variety of myocardial work parameters and provides a new method for clinical research to assess myocardial function, which is expected to become a new prediction method for CAD.

Diastolic Cardiac Function by MRI-Imaging Capabilities and Clinical Applications

Most cardiac studies focus on evaluating left ventricular (LV) systolic function. However, the assessment of diastolic cardiac function is becoming more appreciated, especially with the increasing prevalence of pathologies associated with diastolic dysfunction like heart failure with preserved ejection fraction (HFpEF). Diastolic dysfunction is an indication of abnormal mechanical properties of the myocardium, characterized by slow or delayed myocardial relaxation, abnormal LV distensibility, and/or impaired LV filling. Diastolic dysfunction has been shown to be associated with age and other cardiovascular risk factors such as hypertension and diabetes mellitus. In this context, cardiac magnetic resonance imaging (MRI) has the capability for differentiating between normal and abnormal myocardial relaxation patterns, and therefore offers the prospect of early detection of diastolic dysfunction. Although diastolic cardiac function can be assessed from the ratio between early and atrial filling peaks (E/A ratio), measuring different parameters of heart contractility during diastole allows for evaluating spatial and temporal patterns of cardiac function with the potential for illustrating subtle changes related to age, gender, or other differences among different patient populations. In this article, we review different MRI techniques for evaluating diastolic function along with clinical applications and findings in different heart diseases.

Predictive factors for new-onset atrial fibrillation in acute coronary syndrome patients undergoing percutaneous coronary intervention

BACKGROUND

The aim of this study is to investigate the predictive factors for new-onset atrial fibrillation (AF) in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI).

METHODS

A total of 934 ACS patients admitted into the Department of Cardiology from February 2015 to February 2017 were collected. All patients were treated with PCI after admission and followed up for 1 year. Data of patients, such as age, gender, past medical history, dyslipidemia, cardiogenic shock, heart failure, medication, culprit vessel, echocardiographic characteristics and types of ACS were collected. Patients enrolled were divided into AF group and non-AF group according to whether there was new-onset AF or not. The clinical baseline data, coronary angiographic results and echocardiographic characteristics were compared between the two groups. The left atrial volume index (LAVI) and incidence rate of AF were compared using the histogram, and multivariate Logistic regression analyses were conducted for independent risk factors for new-onset AF in ACS patients undergoing PCI.

RESULTS

In terms of clinical baseline data and coronary angiographic results, the average age and proportions of female, hypertension, heart failure, cardiogenic shock and application of β-receptor blockers and antiarrhythmic drugs in AF group were significantly increased compared with those in non-AF group (P<0.05). In terms of echocardiographic characteristics, the mitral E peak, LAVI, and proportions of E/Em>15 and proportions of left ventricular ejection fraction (LVEF) <40% were significantly increased (P<0.05), but LVEF was obviously decreased (P<0.05) in AF group compared with those in non-AF group. According to multivariate Logistic regression analyses, cardiogenic shock, LAVI and age were independent risk factors for new-onset AF in ACS patients undergoing PCI. The comparison among patients with different LAVI showed that with the increase of LAVI, the incidence rate of AF was gradually increased.

CONCLUSIONS

Cardiogenic shock, LAVI and advanced age are independent predictive factors for new-onset AF in ACS patients undergoing PCI. The incidence rate of AF was gradually increased with the increase of LAVI.