scholarly journals Left atrial fibrosis: an essential hallmark in chronic mitral regurgitation

2021 ◽  
Vol 31 (1) ◽  
pp. 36-45
Author(s):  
Maria Concetta Pastore ◽  
Giulia Elena Mandoli ◽  
Aleksander Dokollari ◽  
Gianluigi Bisleri ◽  
Matteo Lisia ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Left Atrial ◽  
Surgical Techniques ◽  
Volume Overload ◽  
Optimal Timing ◽  
Minimally Invasive Surgical ◽  
Noninvasive Estimation ◽  
Lv Remodeling ◽  
Left Atrial Fibrosis

Chronic mitral regurgitation (MR) is the second valvular heart disease for incidence, which worsening severity gradually affects all cardiac chambers and leads to poor outcome if untreated. The recent development of minimally invasive surgical techniques and percutaneous intervention has reduced the operative risk, allowing a more confident referral of these patients for intervention. Therefore, there is a growing need of reliable markers to select the best therapeutic strategies and to identify the optimal timing for intervention. Myocardial fibrosis (MF) gradually occurs as a result of left atrial and ventricular (LA and LV) remodeling due to MR pressure and volume overload. It has been identifi ed as an index of clinical outcome and arrhythmic risk in patients with MR. Particularly, the assessment of LA fi brosis not only allows to define different MR etiology, but also was associated with prognosis and atrial fibrillation (AF) burden. Nowadays, noninvasive estimation of MF is possible through the use of advanced imaging modalities, particularly cardiac magnetic resonance and speckle tracking echocardiography. This review discusses the role of LA fibrosis as a diagnostic and prognostic marker in patients with MR and its quantification by noninvasive multimodality cardiac imaging.

scholarly journals Dissociation between cardiomyocyte function and remodeling with β-adrenergic receptor blockade in isolated canine mitral regurgitation

2008 ◽  
Vol 295 (6) ◽  
pp. H2321-H2327 ◽  
Author(s):  
Betty Pat ◽  
Cheryl Killingsworth ◽  
Thomas Denney ◽  
Junying Zheng ◽  
Pamela Powell ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Adrenergic Receptor ◽  
Volume Overload ◽  
Left Ventricular ◽  
Ultrastructural Changes ◽  
Receptor Blockade ◽  
Lv Mass ◽  
Lv Remodeling ◽  
Fractional Shortening ◽  
Adrenergic Receptor Blockade

The low-pressure volume overload of isolated mitral regurgitation (MR) is associated with increased adrenergic drive, left ventricular (LV) dilatation, and loss of interstitial collagen. We tested the hypothesis that β1-adrenergic receptor blockade (β1-RB) would attenuate LV remodeling after 4 mo of MR in the dog. β1-RB did not attenuate collagen loss or the increase in LV mass in MR dogs. Using MRI and three-dimensional (3-D) analysis, there was a 70% increase in the LV end-diastolic (LVED) volume-to-LV mass ratio, a 23% decrease in LVED midwall circumferential curvature, and a >50% increase in LVED 3-D radius/wall thickness in MR dogs that was not attenuated by β1-RB. However, β1-RB caused a significant increase in LVED length from the base to apex compared with untreated MR dogs. This was associated with an increase in isolated cardiomyocyte length (171 ± 5 μm, P < 0.05) compared with normal (156 ± 3 μm) and MR (165 ± 4 μm) dogs. Isolated cardiomyocyte fractional shortening was significantly depressed in MR dogs compared with normal dogs (3.73 ± 0.31 vs. 5.02 ± 0.26%, P < 0.05) and normalized with β1-RB (4.73 ± 0.48%). In addition, stimulation with the β-adrenergic receptor agonist isoproterenol (25 nM) increased cardiomyocyte fractional shortening by 215% ( P < 0.05) in β1-RB dogs compared with normal (56%) and MR (50%) dogs. In summary, β1-RB improved LV cardiomyocyte function and β-adrenergic receptor responsiveness despite further cell elongation. The failure to attenuate LV remodeling associated with MR could be due to a failure to improve ultrastructural changes in extracellular matrix organization.

P4379Pathophysiology of left atrial filling in mitral regurgitation. A new volumetric flow rate index describing disturbed left atrial filling behavior in mitral regurgitation by 3D TTE

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D Frumkin ◽  
K Stangl ◽  
A Muegge ◽  
T Buck ◽  
B Plicht
Keyword(s):  
Mitral Regurgitation ◽  
Left Atrium ◽  
Flow Rate ◽  
Left Atrial ◽  
Volume Overload ◽  
Volumetric Flow Rate ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Mean Flow ◽  
Flow Rates

Abstract Background In chronic mitral regurgitation (MR) the left atrium (LA) is one of the first cardiac structures involved in remodeling by progressive volume overload. Real-time three-dimensional echocardiography is able to monitor volumetric changes of the left atrium during the heart cycle. Purpose We hypothesized that chronic volume overload due to MR leads to detectable changes in the LA filling behavior described by mean and maximum filling flow rates and their relation called volumetric flow rate index. Methods We prospectively analyzed data of 36 patients in different stages of chronic MR and 13 patients without MR. Transthoracic echocardiography was conducted using the Epiq 7G Ultrasound System. Standard 2D- and 3D apical 4-chamber views were recorded and stored for offline analysis. We generated volume-time-curves by 3D volume analysis to derive mean and maximum volumetric flow rates during LA reservoir, conduit and pump phase. Volumetric flow rate index was calculated as the quotient of mean flow rate/maximum flow rate. Results Average MR severity, calculated with the MR Scoring system introduced from Buck et al. and implicated in the ESC Guidelines, was 6.2 points (±2.5) according to Grade I-II. We included 13 patients without MR, 18 with mild MR, 12 patients with moderate MR, 6 patients with severe MR. Left ventricular ejection fraction was similar in the different groups (51,2±12,3%). Maximum and mean flow rate showed no significant correlation with MR severity. Correlation of MR severity with LA dilation (ml/m2 BSA) was r=0.41; p<0.001. Flow rate index showed strong significant correlation with MR severity in left atrial reservoir phase (r=−0.75; p<0.001). There was no statistically relevant difference of volumetric flow rate parameters in left atrial pump and conduit phase. Line chart Conclusions We observed a significant correlation of the volumetric flow rate index to MR severity in the left atrial reservoir phase with stronger correlation than MR severity to left atrial dilation. The results of this work encourage further investigations to establish the presented volumetric flow rate index as a progression marker of MR and to evaluate its prognostic value.

Stiff Left Atrial Syndrome; Prospects and Possibilities. Retrospective Analysis and Review of the Literature

2019 ◽  
Vol 15 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Muhammad Ali Chaudhry ◽  
Allen Johnson ◽  
James Thomas Heywood
Keyword(s):  
Atrial Fibrillation ◽  
Mitral Regurgitation ◽  
Left Atrial ◽  
Diuretic Therapy ◽  
Volume Overload ◽  
Right Heart Catheterization ◽  
Venous Hypertension ◽  
Heart Catheterization ◽  
Right Heart

Objectives: Stiff left atrial syndrome is an intriguing clinical phenomena characterized by reduced left atrial compliance, pulmonary venous hypertension and exacerbations of volume overload. We conducted a retrospective review of patients diagnosed with stiff left atrial syndrome at our center. Methods: All patients admitted to our hospital with volume overload and pulmonary venous hypertension who were diagnosed with stiff left atrial syndrome based on evidence by echocardiogram and right heart catheterization between July 2011 and July 2013 were included in this retrospective review. Results: Twentythree patients (mean age 73 ± 11 years, 39% male and 61% female) were diagnosed with stiff left atrial syndrome at our center. Thirty-five percent had persistent while 39% had permanent atrial fibrillation. Mean duration of atrial fibrillation was 7.6 ± 2.1 years. Forty-three percent of patients had long standing hypertension. There was no mitral regurgitation in 39% of patients while 48% had mild mitral regurgitation. On right heart catheterization, mean right atrial pressure was 12.6±4.8 mm of Hg, mean pulmonary arterial pressure was 33±7.2 mm of Hg, mean pulmonary capillary wedge pressure was 24.8± 4.2mm of Hg while peak V waves were seen at mean of 37.8± 5.3 mm of Hg. Mean left atrial volume index was 49.8±17.1 mL/m 2. After the initial diagnosis with a two year follow- up, there were no readmissions in 65% of patients who were on appropriate diuretic therapy and had regular clinical visits. Frequent readmissions were seen in 35% of patients inspite of appropriate diuretic therapy. All-cause mortality rate was 4.3% at two year follow up. Conclusion: In patients with stiff left atrial syndrome, the presence of left atrial dilation, long standing atrial fibrillation and hypertension are the key factors associated with pathogenesis and clinical course. Close follow up and monitoring of volume status is essential to prevent hospital readmissions and improve long term prognosis.

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