Atrium electromechanical interval in left ventricular diastolic dysfunction

Echocardiography-derived total atrial conduction time (PA-TDI duration): risk stratification and guidance in atrial fibrillation management

Atrial fibrillation (AF) is a major cause of cardiovascular morbidity and mortality. To early detect and to avoid AF-related complications, several cardiac imaging modalities and approaches aim to quantify the severity of the underlying atrial cardiomyopathy (i.e., the extent of atrial remodeling). However, most established cardiac imaging modalities just incorporate single components of atrial remodeling and do not reflect the complete multifactorial process, which may contribute to their limited predictive value. Echocardiography-derived PA-TDI duration is a sophisticated echocardiographic parameter to assess total atrial conduction time and directly reflects both electrical and structural changes to the atria. Therefore, PA-TDI duration provides a more comprehensive quantification of the extent of atrial remodeling than other imaging modalities. In this article we review the role of PA-TDI duration as a marker of atrial remodeling and summarize the available data on PA-TDI duration to identify patients at risk for AF, as well as to guide AF management. Moreover, we discuss how to assess PA-TDI duration and provide recommendations on the implementation of PA-TDI duration into routine clinical care.

P wave peak time: A time window to evaluate left ventricular diastolic function

The activation time from electrical signals to chamber conformational change has long been demonstrated to associate with LV performance and ventriculo-arterial coupling with prognostic implications in heart failure patients. P wave peak time (PWPT), an easily obtainable parameter from conventional surface electrocardiography, represents the time taken for excitation spreading from sinoatrial node to the maximal summation of positive deflection from both atria. Increased PWPT denotes prolonged intra- or inter-atrial conduction time and indicates elevated intra-atrial pressure. As shown in a recently published study, PWPT was highly correlated with LV end diastolic pressure (LVEDP) derived from direct measurement during cardiac catheterization. With its objective and easily obtainable nature, clinical application of PWPT to evaluate diastolic function can be expected, if more studies in different populations can confirm its clinical utility.

Assessment of atrial conduction times in patients with mild diastolic dysfunction and normal atrial size

Objective:

Abnormalities in atrial electromechanical delays (EMDs) are considered independent predictors of atrial fibrillation and can reflect atrial remodeling. The main purpose in this study was to compare inter-left and right intra-atrial EMDs of patients with mild left ventricular (LV) diastolic dysfunction, without left atrial (LA) structural remodeling in the absence of high filling pressure, with healthy individuals.

Methods:

In this prospective study, a total of 41 consecutive outpatients who were referred to our echocardiography laboratory with mild diastolic dysfunction (age: 60.9±9.6 years) and 45 healthy control subjects who were referred from an outpatient clinic for check-up (age: 32.2±10.3 years) with normal diastolic function were enrolled into this study. All subjects had normal LA volume and normal right atrial area and did not have high filling pressure. Diastolic dysfunction were determined per American Society of Echocardiography recommendations; so, the following indices were measured: peak early (E) and atrial (A) flow velocities (cm/s), E/A ratio, and deceleration time (DT) (ms) of mitral inflow, systolic (S) and diastolic (D) pulmonary vein wave velocities (cm/s) by pulse wave Doppler, and e’ in septal and lateral mitral annulus by pulse wave tissue Doppler. Time interval from the onset of P wave on the ECG to the beginning of the late diastolic wave (Am wave) on tissue Doppler trace, which is named PA, was obtained from the lateral and septal mitral annulus and right ventricular (RV) tricuspid annulus as atrial conduction times (ACTs) and were named lateral PA, septal PA, and RV PA, respectively. The difference between lateral PA and septal, PA septal and RV PA was defined as left and right intra-atrial EMD, respectively. The difference between lateral PA and RV PA was defined as inter-atrial EMD. Data analysis was done by independent student’s t-test, Mann-Whitney U test, χ² test, Spearman rank order, Pearson’s correlation coefficient, and multivariate regression analysis in the appropriate site.

Results:

A, DT, S/D ratio, and E/e’ (average) were significantly lower in the control group, and E, D, E/A ratio, e’ septal, and e’ lateral wall were significantly lower in the patient group. Atrial conduction times were longer in the patient group, but in the multivariate analysis, there was no correlation between ACTs and diastolic dysfunction. There was no significant difference in left intra-atrial EMD (14.2±9.7 ms vs. 16.4±11.4 ms; p=0.336), right intra-atrial EMD (12.8±12.2 ms vs. 15.4±12.1 ms; p=0.321), and inter-atrial EMD (26.9±13.7 ms vs. 31.7±13.7 ms; p=0.108) between the two groups. Multivariate analysis showed no correlation between inter- and intra-atrial EMDs and diastolic dysfunction.

Conclusion:

There was no significant difference in ACTs and inter-atrial and left and right intra-atrial EMD in patients with mild LV diastolic dysfunction and normal LA volume in the absence high filling pressure compared with normal subjects.

Placental growth factor may predict increased left ventricular mass index in patients with mild to moderate chronic kidney disease--a prospective observational study

Background

Placental growth factor [PlGF) is a cardiovascular (CV) risk marker, which is related to left ventricle hypertrophy (LVH) in animal models. Currently there are no data available regarding the possible relationship of PlGF and the development of LVH or diastolic dysfunction in patients with chronic kidney disease (CKD) and the relationship of PlGF to other CV risk factors in CKD patients. The aim of our study was to determine the possible association of PlGF and several other CV risk markers to echocardiographic parameters in CKD population.

Methods

We prospectively examined selected laboratory (PlGF, fibroblast growth factor-23 -FGF23, vitamin D, parathyroid hormone, extracellular newly identified RAGE-binding protein - EN-RAGE, B-type natriuretic peptide - BNP) and echocardiographic parameters in 62 patients with CKD 2–4. Mean follow-up was 36 ±10 months. Laboratory and echocardiographic data were collected 2–3 times, at the shortest interval of 12 months apart. Multivariate regression analysis was used to detect independent correlations of variables.

Results

Increased left ventricular mass index (LVMI, g/m^2.7) was found in 29% patients with CKD 2–4, left ventricular (LV) diastolic dysfunction was detected in 74.1% patients (impaired LV relaxation in 43.5% patients and pseudonormal pattern in 30.6% patients). After 36 ± 10 months increased LVMI was found in 37.1% patients with CKD 2–4, LV diastolic dysfunction was detected in 75.8% patients (impaired LV relaxation in 43.5% patients and pseudonormal pattern in 32.3% patients). Following independent correlations were found: LVMI was related to PlGF, cholesterol, BNP, systolic blood pressure and serum creatinine. EN-RAGE correlated positively with left atrial diameter and inversely with E/A ratio. During the follow-up we found a significant increase in LVMI and left atrial diameter, whereas a significant decrease in LVEF was noted.

Conclusion

According to our data, PlGF is independently related to increased LV mass in CKD, whereas EN-RAGE is more likely related to diastolic dysfunction in this population.