Value of three-dimensional echocardiography study of left ventricle function correlated to coronary arterial dominance in predicting the outcome of primary percutaneous coronary intervention

Clinical Significance of Coronary Arterial Dominance: A Review of the Literature

Coronary dominance describes the anatomic variation of coronary arterial supply, notably as it relates to perfusion of the inferior cardiac territories. Differences in the development and outcome in select disease states between coronary dominance patterns are increasingly recognized. In particular, observational studies have identified higher prevalence of poor outcomes in left coronary dominance in the setting of ischemic, conduction, and valvular disease. In this qualitative literature review, we summarize anatomic, physiologic, and clinical implications of differences in coronary dominance to highlight current understanding and gaps in the literature that should warrant further studies.

The Role of Strain by Cardiac Magnetic Resonance Imaging in Predicting the Prognosis of Patients with Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by thrombotic obstruction of the pulmonary arteries, and right ventricular (RV) dysfunction is a major cause of death. Cardiac magnetic resonance (CMR) is the gold standard for assessing heart wall deformation; therefore, we aimed to determine the prognostic value of CMR strain in patients with CTEPH. Strain derived by CMR was measured at the time of diagnosis in 45 patients with CTEPH, and the relationship between RV strain and prognosis was determined through follow-up. The value of RV strain in the prognostic model was compared with that of pulmonary arterial hypertension (PAH) risk stratification. The RV global peak longitudinal strain (GLS) and global peak circumferential strain (GCS) in CTEPH patients were lower than the normal references of RV strain in the control group. GLS and longitudinal strain in the basal segment were independent risk factors for adverse events (P < .050). Adding CMR parameters to PAH risk stratification improved its predictive power in patients with CTEPH. GLS and GCS scores were impaired in patients with chronic RV overload. RV strain derived by CMR imaging is a promising noninvasive tool for the follow-up of patients with CTEPH.

Age- and gender-related normal references of right ventricular strain values by tissue tracking cardiac magnetic resonance: results from a Chinese population

Background

Myocardial deformation is a sensitive marker for sub-clinical myocardial dysfunction and carries independent prognostic significance across a broad range of cardiovascular diseases. Reproducible and repeatable assessment of right ventricular (RV) function is vital for monitoring congenital and acquired heart diseases. The purpose of this study was to determine the normal references of RV strain and strain rate values using tissue tracking cardiac magnetic resonance imaging (MRI).

Methods

A cohort of 120 normal human subjects from each decade of life between 20 and 70 without cardiac diseases were enrolled in this study. Retrospectively, electrocardiogram (ECG) gating cardiac MRI imaging was performed at 3.0T with balanced steady-state free precession (bSSFP) imaging. RV global and segmental myocardial strains were analyzed by tissue tracking by two experienced observers.

Results

The global peak longitudinal strain (GLS) and global peak radial strain (GRS) was -24.3±4.7 and 23.0±8.5 respectively. For the peak circumferential strains (GCS), the values for global, basal, mid-cavity, and apical segments were -13.3±4.1, -13.1±4.0, -12.5±4.7, and -15.9±5.8, respectively. There were significant gender differences in peak GRS (P=0.009) and at the base (P=0.017) and the mid-cavity (P=0.011) with greater deformation in females than in males. There were also significant age differences in GRS (P<0.001), GCS for basal (P<0.001), and mid-cavity segments (P=0.037). On Bland-Altman analysis, peak GLS and GRS had the best intra-observer agreement (mean bias, -0.13±0.51; 95% CI, -1.13-0.87) and inter-observer (mean bias, 0.054±0.31; 95% CI, -0.55-0.66) agreement, respectively.

Conclusions

Normal values of RV deformation for healthy individuals using tissue tracking cardiac magnetic resonance (CMR-TT) provided good RV peak strain reproducibility. There was a significant correlation between RV strain or strain rate parameters with either age or sex.