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Echocardiographic Assessment of Left Atrial Systolic Function after Percutaneous Mitral Balloon Valvuloplasty Using Tissue Doppler Imaging

Hasan MN, Banarjee SK, Ahsan SA, Habib SM, Mahmood M

Mymensingh Med J, 2018 Oct;27(4):851-858.
PMID: 30487504

Mitral stenosis (MS) affects left atrial (LA) function as a result of hemodynamic and myocardial factors that causes significant symptoms and complications. Conventional echocardiographic methods have been practicing to see the improvement of left atrial function after successful percutaneous mitral balloon valvuloplasty (PMBV). Introduction of tissue doppler imaging allows direct and non-invasive measurement of myocardial velocities. The aim of the study was to evaluate LA functions after PMBV using colour tissue doppler imaging. This cross sectional study was performed in Cardiology department of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from March 2014 to February 2015. Forty six (46) patients (28 females, mean age: 28.96±5.78 years) presenting with mitral valve stenosis who fulfilled the indications for PMBV were included in the study. Within 24 hours before PMBV, all the patients underwent colour tissue doppler study in addition to routine conventional echocardiographic examinations. Late diastolic velocities (A') measured at the septal and lateral annuli were recorded. All the measurements were repeated 24 hours after PMBV. The PMBV was done using the Inoue technique. After PMBV mitral valve areas (MVA) were significantly increased. Maximum and mean gradients, LA diameter, LA area, LA volume, systolic pulmonary arterial pressure and mean LA pressures were decreased while septal and lateral A' were significantly (p<0.001) increased. Lateral and septal A' velocities were correlated with MVA and inversely related to LA pressure measured invasively during PMBV. Tissue doppler velocities illustrated improvement of left atrial systolic function after PMBV in relation to decreased mean left atrial pressure and increased mitral valve area. Therefore, tissue doppler Imaging is a useful tool to detect improvement of left atrial systolic function after PMBV in patients with mitral stenosis.

Matched MeSH terms: Atrial Function, Left
Fulltext Effects of extracts and fractions of Gynura procumbens on rat atrial contraction

Abrika OS, Yam MF, Asmawi MZ, Sadikun A, Dieng H, Hussain EA

J Acupunct Meridian Stud, 2013 Aug;6(4):199-207.
PMID: 23972242 DOI: 10.1016/j.jams.2013.01.020

There is currently a great deal of research interest in utilizing plant compounds against human diseases, including hypertension. The present study investigated the effects of different extracts and fractions from leaves of Gynura procumbens Merr. on rat atrial contraction in vitro. Isolated left and right atria, mounted in a 20-ml organ bath, were allowed to equilibrate for 15 min before the application of the extracts or fractions. The extracts (petroleum-ether extract (PE) and methanol extract (ME)) and the fractions (chloroform fraction (CHL), ethyl-acetate fraction (EA), n-butanol fraction (NB) and water fraction (WA) of the methanol extract) were tested at three concentrations (0.25, 0.5 and 1.0 mg/ml), with a β-adrenergic agonist (isoprenaline) as a control. All data on contraction responses were log-transformed and analyzed. When exposed to the different extracts, both atria tended to exhibit greater contractive responses with the NB whereas cardiac contractions had a tendency to be reduced with most other extracts. For a given extract, the contraction responses were particularly greater at 0.5 mg/ml for the right atrium and at 1 mg/ml for the left atrium. Further analysis focusing on the NB fraction revealed that positive inotropism was greater in left atria exposed to highly-concentrated F2 and F3 sub-fractions. Taken together, our results suggest that NB extracts and fractions from the G. procumbens-leaf methanol extract have positive inotropic activities and, hence, can be considered as an alternative/traditional medicine against increased blood pressure in humans or can be used in strategies aimed at finding antihypertensive biomolecules from an accessible source.

Matched MeSH terms: Atrial Function/drug effects
Left atrial strain: a multi-modality, multi-vendor comparison study

Pathan F, Zainal Abidin HA, Vo QH, Zhou H, D'Angelo T, Elen E, et al.

Eur Heart J Cardiovasc Imaging, 2021 01 01;22(1):102-110.
PMID: 31848575 DOI: 10.1093/ehjci/jez303

AIMS: Left atrial (LA) strain is a prognostic biomarker with utility across a spectrum of acute and chronic cardiovascular pathologies. There are limited data on intervendor differences and no data on intermodality differences for LA strain. We sought to compare the intervendor and intermodality differences between transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) derived LA strain. We hypothesized that various components of atrial strain would show good intervendor and intermodality correlation but that there would be systematic differences between vendors and modalities.
METHODS AND RESULTS: We evaluated 54 subjects (43 patients with a clinical indication for CMR and 11 healthy volunteers) in a study comparing TTE- and CMR-derived LA reservoir strain (ƐR), conduit strain (ƐCD), and contractile strain (ƐCT). The LA strain components were evaluated using four dedicated types of post-processing software. We evaluated the correlation and systematic bias between modalities and within each modality. Intervendor and intermodality correlation was: ƐR [intraclass correlation coefficient (ICC 0.64-0.90)], ƐCD (ICC 0.62-0.89), and ƐCT (ICC 0.58-0.77). There was evidence of systematic bias between vendors and modalities with mean differences ranging from (3.1-12.2%) for ƐR, ƐCD (1.6-8.6%), and ƐCT (0.3-3.6%). Reproducibility analysis revealed intraobserver coefficient of variance (COV) of 6.5-14.6% and interobserver COV of 9.9-18.7%.
CONCLUSION: Vendor derived ƐR, ƐCD, and ƐCT demonstrates modest to excellent intervendor and intermodality correlation depending on strain component examined. There are systematic differences in measurements depending on modality and vendor. These differences may be addressed by future studies, which, examine calibration of LA geometry/higher frame rate imaging, semi-quantitative approaches, and improvements in reproducibility.

Matched MeSH terms: Atrial Function, Left/physiology*
Left atrial volume index is an independent predictor of major adverse cardiovascular events in acute coronary syndrome

Gunasekaran R, Maskon O, Hassan HH, Safian N, Sakthiswary R

Can J Cardiol, 2012 Sep-Oct;28(5):561-6.
PMID: 22560463 DOI: 10.1016/j.cjca.2012.02.015

Left atrial volume index (LAVI) is well proven to be a reliable method of determining left atrial size, which has prognostic implications in cardiovascular diseases. Studies demonstrate that increased LAVI is a predictor of mortality in myocardial infarction, but its association with other major adverse cardiovascular events (MACEs) among patients post acute coronary syndrome (ACS) has not been adequately evaluated.

Matched MeSH terms: Atrial Function, Left/physiology
Comparison of relaxin receptors in rat isolated atria and uterus by use of synthetic and native relaxin analogues

Tan YY, Wade JD, Tregear GW, Summers RJ

Br J Pharmacol, 1998 Feb;123(4):762-70.
PMID: 9517397

1. The receptors for relaxin in the rat atria and uterus were investigated and compared by use of a series of synthetic and native relaxin analogues. The assays used were the positive chronotropic and inotropic effects in rat spontaneously beating, isolated right atrium and electrically driven left atrium and the relaxation of K+ precontracted uterine smooth muscle. 2. Relaxin analogues with an intact A- and B-chain were active in producing powerful chronotropic and inotropic effects in the rat isolated atria at nanomolar concentrations. Single-chain analogues and structural homologues of relaxin such as human insulin and sheep insulin-like growth factor I had no agonist action and did not antagonize the effect of the B29 form of human gene 2 relaxin. 3. Shortening the B-chain carboxyl terminal of human gene 1 (B2-29) relaxin to B2-26 reduced the activity of the peptide and removal of another 2 amino acid residues (B2-24) abolished the activity. This suggests that the B-chain length may be important for determination of the activity of relaxin. More detailed studies are needed to determine the effect of progressive amino acid removal on the structure and the bioactivity of relaxin. 4. Porcine prorelaxin was as active as porcine relaxin on a molar basis, suggesting that the presence of the intact C-peptide did not affect the binding of the prorelaxin to the receptor to produce functional responses. 5. Relaxin caused relaxation of uterine longitudinal and circular smooth muscle precontracted with 40 mM K+. The pEC50 values for human gene 2 and porcine relaxins were lower than those in the atrial assay, but rat relaxin had similar pEC50 values in both atrial and uterine assays. Rat relaxin was significantly less potent than either human gene 2 or porcine relaxin in the atrial assay, but in the uterine assay they were equipotent. The results suggest that the relaxin receptor or the signalling pathway in rat atria may differ from that in the uterus.

Matched MeSH terms: Atrial Function