Reduction In Atrial Size Research Articles

Abstract 11477: Assessing New Onset of Atrial Arrhythmia in Patients Undergoing Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy

Introduction: Alcohol septal ablation (ASA) is an effective percutaneous procedure used to treat refractory hypertrophic obstructive cardiomyopathy (HOCM). ASA relieves left ventricular outflow tract (LVOT) obstruction by creating a targeted infarction in the septal muscle. Diastolic dysfunction and mitral regurgitation are responsible for increased left atrial pressure which contributes to left atrial ectopy. We seek to assess the incidence of atrial arrhythmias post-ASA and identify predictors to risk stratify these patients. Methods: Using a patient database maintained internally, 144 consecutive patients who underwent ASA for HOCM between March 2017 and February of 2022 at MUSC were retrospectively reviewed. Patients were selected based on the need for cardiac event monitoring after ASA. Patients were retrospectively analyzed for a previous history of atrial fibrillation (AF) as well as a new onset of AF after ASA. SPSS statistics was used for statistical analysis. Results: A total of 31 patients met final inclusion criteria. During the monitored time, seven patients (22.58%) developed a new onset of AF after ASA. Patients who developed AF post-ASA were found to have a statistically higher left atrial end-systolic volume index (LAESVi, mL/m 2 ) and left ventricular end-diastolic pressure (LVEDP, mmHg) (59.96 ± 8.93, 34.33 ± 11.54) when compared to those who did not develop AF (41.13 ± 13.93, 23.33 ± 9.06 (p=0.0003, p=0.0331)). Conclusions: In this high-risk proportion of patients who required cardiac monitoring post-ASA, there is a higher-than-expected risk for new onset of AF. The left atrial size and left ventricular filling pressures before ablation were the only significant predictors for development of atrial arrhythmias after ASA. Longer-term evaluation will be able to address if the expected reduction in atrial size and LVOT gradient after ASA will reduce the overall long-term burden of atrial arrhythmias.

Reduction of Atrial Septal Defect Size After Catheter Ablation for Atrial Tachyarrhythmia and Its Predictive Factors

<h2>Abstract</h2> The prevalence of atrial tachyarrhythmia is high in patients with atrial septal defect (ASD), and catheter ablation (CA) is often performed before percutaneous ASD closure. We aimed to clarify the effect of CA on the ASD size. We analysed 16 patients with secundum ASD who had a history of CA for atrial tachyarrhythmia and underwent ASD size evaluation before and after CA. The size of ASD significantly decreased after CA. Younger age and lower tricuspid regurgitation pressure gradients and pulmonary arterial systolic pressures were associated with size reduction. These factors are crucial for making strategies of percutaneous ASD closure.

Asymmetric Hapln1a drives regionalized cardiac ECM expansion and promotes heart morphogenesis in zebrafish development.

AimsVertebrate heart development requires the complex morphogenesis of a linear tube to form the mature organ, a process essential for correct cardiac form and function, requiring coordination of embryonic laterality, cardiac growth, and regionalized cellular changes. While previous studies have demonstrated broad requirements for extracellular matrix (ECM) components in cardiac morphogenesis, we hypothesized that ECM regionalization may fine tune cardiac shape during heart development.Methods and resultsUsing live in vivo light sheet imaging of zebrafish embryos, we describe a left-sided expansion of the ECM between the myocardium and endocardium prior to the onset of heart looping and chamber ballooning. Analysis using an ECM sensor revealed the cardiac ECM is further regionalized along the atrioventricular axis. Spatial transcriptomic analysis of gene expression in the heart tube identified candidate genes that may drive ECM expansion. This approach identified regionalized expression of hapln1a, encoding an ECM cross-linking protein. Validation of transcriptomic data by in situ hybridization confirmed regionalized hapln1a expression in the heart, with highest levels of expression in the future atrium and on the left side of the tube, overlapping with the observed ECM expansion. Analysis of CRISPR-Cas9-generated hapln1a mutants revealed a reduction in atrial size and reduced chamber ballooning. Loss-of-function analysis demonstrated that ECM expansion is dependent upon Hapln1a, together supporting a role for Hapln1a in regionalized ECM modulation and cardiac morphogenesis. Analysis of hapln1a expression in zebrafish mutants with randomized or absent embryonic left–right asymmetry revealed that laterality cues position hapln1a-expressing cells asymmetrically in the left side of the heart tube.ConclusionWe identify a regionalized ECM expansion in the heart tube which promotes correct heart development, and propose a novel model whereby embryonic laterality cues orient the axis of ECM asymmetry in the heart, suggesting these two pathways interact to promote robust cardiac morphogenesis.

A study to assess the impact of left atrial size reduction in outcome of the patients undergoing mitral valve surgery for mitral valve disease with left atrial enlargement in a tertiary care hospital

Background: Rheumatic mitral valve disease (mitral stenosis or regurgitation) remains the common heart disease in developing countries. Mitral valve is involved in 99% of cases. The prognostic implication of LA (left atrium) size has also been shown in high-risk subgroups, such as patients with acute myocardial infarction, atrial arrhythmia, LV dysfunction, or dilated cardiomyopathy, and patients undergoing valve replacement for aortic stenosis and mitral regurgitations. Objective of the study was to study the impact of left atrial size reduction in patients undergoing mitral valve surgery for mitral valve disease with left atrial enlargement on clinical outcome and echocardiographic parameters.Methods: A prospective study was done at department of cardiovascular and thoracic surgery, Sri Venkateshwara institute of medical sciences, Tirupati from June 2012 and June 2013.The study population consisted of patients with rheumatic mitral valve disease with or without tricuspid valve disease with left atrial size enlargement who underwent mitral valve surgery alone and mitral valve surgery with left atrial reduction. Twenty consecutive subjects were taken in each group during the study period. Results: The age range is 21 to 61 years. There means age is 39.7±10.3 years. in the study group. Following MVR significant improvement in the NYHA (New York Heart Association) functional class was noted in all the patients. The decrease in RVSP, LA size, and TR was noted in all the patients.Conclusions: It seems reasonable to suggest that patients who undergo LA reduction along with MVR have significant improvement in clinical outcome and NYHA functional class with less thromboembolic complications during long term follow up.

A Giant Left Atrium due to Rheumatic Mitral Regurgitation, Outcome after Left Atrial Reduction Surgey with Mitral Valve Replacement

A trans-thoracic echocardiography and chest radiograph of a 26 year old lady diagnosed as rheumatic mitral regurgitation with atrial fibrillation revealed a giant left atrium of 10.9 cm size with symptoms of dyspnoea and palpitation. The patient was treated with left atrial size reduction along with mitral valve replacement surgery and showed an excellent and quick recovery with total disappearance of symptoms and restoration of sinus rhythm only within few days.University Heart Journal Vol. 14, No. 1, Jan 2018; 42-44

Rapid Reduction in Right Atrial Size after Amplatzer Septal Occluder Placement Results in Disc Distortion and Chest Pain Necessitating Device Removal

Rapid Reduction in Right Atrial Size after Amplatzer Septal Occluder Placement Results in Disc Distortion and Chest Pain Necessitating Device Removal

Early and long-term outcomes and quality of life after concomitant mitral valve surgery, left atrial size reduction, and radiofrequency surgical ablation of atrial fibrillation.

Objective:Atrial fibrillation (AF) is the most formidable supraventricular tachyarrhythmia, which worsens the natural course of mitral valve disease. In this study, we evaluated early and long-term results and quality of life (QOL) after simultaneous surgical radiofrequency ablation (RFA) of AF, left atrial reduction and mitral valve repair or replacement.Methods:Overall, 147 patients with mitral valve diseases who underwent mitral valve surgery were included in this prospective cohort study. Patients were divided into two groups according to the type of operation: the study group—patients after mitral valve surgery with concomitant radiofrequency surgical ablation and left atrial reduction procedure (54 patients), and the control group—patients undergoing only mitral valve surgery (93 cases). We assessed AF recurrence and sinus rhythm restoration rates and mortality rates, QOL measures, postoperative complications rates, and left atrial size during follow-up.Results:In the study group, sinus rhythm restoration rate in the early postoperative period was 63%, but at the time of discharge it reduced to 29%; after 6 months, it significantly increased to 72% and after 3 years, to 81% (p=0.02). In the control group, the sinus rhythm restored only in 14% after 1 year, and at 3 years, it was 22%, although in the early postoperative period it, was 43%. Analysis of left atrial size before and after surgery showed that dimension significantly reduced in both groups (study group, p=0.013; control group, p=0.024). In addition, in patients undergoing surgical RFA procedure, there was a significant association between shorter heart disease history (p=0.02) and shorter AF history (p=0.074) with maintenance of sinus rhythm. The mortality rate in the study group was 4% (two patients) and in the control group 5% (five patients). Comparison of QOL measures between study and control groups after 1 year showed that patients undergoing concomitant atrial reduction surgery and RFA had significant improvement of QOL physical (p=0.03) and role (p=0.03) functioning, heartbeat (p=0.01), general (p=0.03) and mental health (p=0.01), vitality (p=0.007), and social role (p=0.02) functioning measures as compared to preoperative state, being higher than in patients who underwent only mitral valve surgery.Conclusion:Application of surgical RFA using irrigated cooling electrode and atrial reduction during mitral valve surgery is associated with higher restoration and maintenance of SR as compared to patients undergoing only mitral valve surgery. We did not observe complications related to AF surgery that required permanent pacemaker implantation. Performing concomitant surgery as surgical RFA, atrial reduction along with mitral valve surgery, improves QOL in the short- and long-term and reduces the feeling of heartbeat and discomfort. (Anatol J Cardiol 2016; 16: 797-803)

Effect of Left Atrial Reduction on Restoration and Maintenance of Sinus Rhythm in Patients Undergoing Mitral Valve Replacement: A Pilot Study.

Background This pilot study aimed to evaluate the effectiveness of posterior left atrial wall plication (T-plasty) in patients with persistent atrial fibrillation (AF) (> 7 days) undergoing mitral valve surgery. Materials and Methods A total of 60 patients who were scheduled for mitral valve replacement were randomly allocated into two groups: one would receive (Group 1; n = 32, mean age; 49.37 ± 9.00) and one would not receive (Group 2; n = 28; mean age 48.64 ± 8.6) left atrial size reduction using T-plasty technique. Patients with a clear indication for combined procedures other than tricuspid valve disease, aortic valve disease, and coronary artery stenosis were not included. Follow-up was performed at 6th, 12th, and 18th months after the operation. Results After the operation, 21 patients (65.6%) in Group 1 and 13 patients (46.4%) in Group 2 regained sinus rhythm (p = 0.13). Mortality did not occur. AF recurrence rates were not significantly different between the groups in three follow-ups. Restoration of sinus rhythm was significantly more common in Group 1 patients than in Group 2 patients during follow-up. Patients in Group 1 had lower left atrial volume indexes than those in Group 2 at the 6th and 12th months, whereas the difference at the 18th month was at the limit of significance. Conclusion We achieved satisfactory results using the T-plasty technique for left atrial size reduction in terms of mid-term restoration and preservation of normal sinus rhythm in patients undergoing mitral valve surgery. Further study may be justified to reveal the prognostic importance of the technique described herein.

Left atrial reduction in modified maze procedure with concomitant mitral surgery.

An association between mitral valve disease and atrial fibrillation is common. Modifications of energy sources have simplified surgical ablation. Left atrial size reduction should improve outcomes of the maze operation. Between 2004 and 2011, 236 patients with permanent atrial fibrillation and mitral valve disease underwent mitral valve surgery and modified biatrial radiofrequency ablation. The study evaluated cardiac rhythm, atrial size, atrial contractility, and survival. The mitral valve was repaired in 88 (37.3%) patients and replaced in 148 (62.7%). The left atrium was reduced in 192 (81.4%) patients: 31 (13.1%) had posterior wall reduction and 161 (68.2%) had right lateral and posterior wall resection. The 30-day mortality was 4.2% (10/236). The median follow-up was 41 months. Actuarial freedom from atrial fibrillation at 1 year and last follow-up was 87.7% and 84.9%, respectively. Predictors of recurrence were preoperative left atrial diameter >60 mm (p = 0.002), postoperative diameter >50 mm (p < 0.001), atrial fibrillation on day 7 (p < 0.001), and technique of reduction (posterolateral/posterior) in patients with atrial size >60 mm (p = 0.017). Atrial fibrillation during follow-up (p = 0.002) and age >60 years (p = 0.003) were significant predictors of poorer survival. During 5-year follow-up, non-atrial fibrillation patients survived significantly longer than atrial fibrillation patients (p = 0.002). Radiofrequency ablation is an effective option for treatment of permanent atrial fibrillation concomitant with mitral valve surgery. Atrial reduction to <50 mm improves success. Elimination of atrial fibrillation significantly prolongs patient survival.

Pinhole Mitral Stenosis

Mini‐AbstractA 46‐year‐old male with known rheumatic heart disease presented in cardiac arrest. He was successfully resuscitated. Two‐dimensional echocardiography showed severe calcific rheumatic mitral stenosis with pinhole opening of the valve. The mitral valve area in planimetry was 0.14 cm2. Three‐dimensional echocardiography confirmed the severity of the stenosis. Patient underwent successful mitral valve replacement with tricuspid valve annuloplasty, Left atrial size reduction, and maze procedure on emergency basis. A mitral valve area of 0.14 cm2 is rarely encountered in clinical practice.

Obstructive sleep apnoea: new associations and approaches

Obstructive sleep apnoea: new associations and approaches

Abstract 9471: Reverse Left Atrial Remodeling, Contraction and Compliance after Radiofrequency Catheter Ablation in Patients with Fixed Atrial Fibrillation

Background &amp; Objectives: Restoration and maintenance of regular rhythm can be achieved by radiofrequency catheter ablation (RFCA) in patients with fixed atrial fibrillation (AF). However, it still remains undetermined whether this reversal is accompanied with amelioration of atrial function, which is associated with reduced risk of subsequent thromboembolic events. Methods: We studied 35 consecutive patients (age: 63±10 years) who had received RFCA for fixed AF. Serial changes in left atrial (LA) size and function were evaluated with echocardiography at baseline, 2 weeks, 3 months and 12 months after the procedure. Results: Thirty-one of 35 patients had recovered and maintained regular rhythm over 12 months following RFCA. Of these 31 patients, 7 patients required second or third sessions. LA size and biplane volume index significantly and progressively reduced over the time during 12-month follow-up periods (p&lt;0.001 and p&lt;0.001, respectively). Atrial contractibility, assessed by time-velocity integral of atrial wave and atrial filling fraction (p&lt;0.001 and p&lt;0.001, respectively), was improved after the procedure. In addition, atrial compliance, assessed by peak systolic strain of LA inferior and septal wall (p&lt;0.001 and p&lt;0.001, respectively), was also improved over the time. LA active contraction, assessed by LA late diastolic strain of LA inferior and septal wall, was appeared at 2 weeks after the procedure, and preserved during the follow-up periods. In addition, this improvement of atrial function was accompanied with that of left “ ventricular ” ejection fraction (p&lt;0.001). Conclusion: Restoration and maintenance of regular rhythm achieved by RFCA was associated with reduction in atrial size and volume as well as improvement in contraction and compliance. Our findings may encourage usefulness of RFCA for fixed AF, expecting risk of reduction of subsequent thlomboembolic events.

Invited Commentary

Invited Commentary

Left Atrial Reduction Plasty: A Novel Technique

We describe a novel technique of left atrial volume reduction in a patient presenting with severe dyspnea from severe mitral insufficiency, giant left atrium, and compressive symptoms of dysphagia and dysphonia. Resection involved circumferential excision of the left atrium anterior to the pulmonary venous vestibule and posterior to the mitral valve and fossa ovalis, including the left atrial appendage. A chordal-sparing bioprosthetic mitral valve replacement, tricuspid valve annuloplasty, and coronary bypass were also performed. Significant reduction of left atrial volume by 50% was achieved and clinical resolution of compressive symptoms was seen at 6-month follow-up.

In patients with an enlarged left atrium does left atrial size reduction improve maze surgery success?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was: In [adults undergoing a maze procedure for atrial fibrillation (AF)], [does left atrial size reduction] compared to [maze surgery alone] improve [maze surgery success]? A total of 58 papers were found using the reported search, of which eight represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Four out of eight papers compared a volume reduction technique as an adjunct to the maze procedure to a maze procedure alone--all four papers reported that atrial volume reduction significantly increased restoration of sinus rhythm: 89.3% vs. 67.2%, P<0.001; 85% vs. 68%, P<0.05; 84% vs. 68%, P<0.05; 90% vs. 69%, P<0.05. Three out of eight papers had no control group but reported good rates of sinus rhythm restoration at last follow-up--90%, 92% and 89%, respectively--despite the study population including atrial enlargement, a risk factor for failure of a maze procedure. One paper reported no benefit of an atrial reduction plasty in patients with a left atrium (LA) >70 mm. An enlarged LA is a risk factor for failure of a maze procedure, and various models of AF suggest that reducing atrial mass and/or diameter may help to abolish the re-entry circuits underlying AF. Furthermore, AF is uncommon when left atrial diameter is <40 mm, so there is at least some physiological basis for atrial reduction surgery in aiding the success of a maze procedure. The evidence suggests that patients with an enlarged (≥ 55 mm) or giant (≥ 75 mm) LA who are at risk of failing to obtain sinus conversion after a standard maze procedure may derive benefit from concomitant atrial reduction surgery using either a tissue excision or a tissue plication technique. However, the evidence is not strong since the papers available are not readily comparable owing to substantial variations in the populations and procedures involved. We therefore, emphasise the need for prospective randomised studies in this area.

Reverse Left Atrial Remodeling after Radiofrequency Catheter Ablation for Non-Paroxysmal Atrial Fibrillation

Background & Objectives: Restoration and maintenance of regular rhythm can be achieved by radiofrequency catheter ablation (RFCA) in patients with non-paroxysmal atrial fibrillation (non-PAF). However, it still remains undetermined whether this reversal is accompanied with amelioration of atrial function, which is associated with reduced risk of subsequent thromboembolic events. Methods: We studied 19 consecutive patients (age: 60±12 years) who had received RFCA for non-PAF. Serial changes in left atrial (LA) size and contraction were evaluated with echocardiography at baseline, 2 weeks, 3 months and 12 months after the procedure. Results: Fourteen of 19 patients had recovered and maintained regular rhythm during the follow-up. LA size and biplane volume index reduced over the time (p<0.01 and p<0.01, respectively). Atrial contractibility, assessed by time-velocity integral of atrial wave and atrial filling fraction (p<0.05 and p<0.05, respectively), was improved after the procedure. In addition, atrial compliance, assessed by peak systolic strain of LA inferior and septal wall (p<0.001 and p<0.001, respectively), was also improved over the time. These improvements of LA function were accompanied with that of left ventricular ejection fraction (p<0.001). Conclusion: Restoration and maintenance of regular rhythm achieved by RFCA was associated with reduction in atrial size and volume as well as improvement in contraction. Our findings may encourage usefulness of RFCA for non-PAF, expecting risk of reduction of subsequent thlomboembolic events.

Differential requirement for BMP signaling in atrial and ventricular lineages establishes cardiac chamber proportionality

The function of an organ relies upon the proper relative proportions of its individual operational components. For example, effective embryonic circulation requires the appropriate relative sizes of each of the distinct pumps created by the atrial and ventricular cardiac chambers. Although the differences between atrial and ventricular cardiomyocytes are well established, little is known about the mechanisms regulating production of proportional numbers of each cell type. We find that mutation of the zebrafish type I BMP receptor gene alk8 causes reduction of atrial size without affecting the ventricle. Loss of atrial tissue is evident in the lateral mesoderm prior to heart tube formation and results from the inhibition of BMP signaling during cardiac progenitor specification stages. Comparison of the effects of decreased and increased BMP signaling further demonstrates that atrial cardiomyocyte production correlates with levels of BMP signaling while ventricular cardiomyocyte production is less susceptible to manipulation of BMP signaling. Additionally, mosaic analysis provides evidence for a cell-autonomous requirement for BMP signaling during cardiomyocyte formation and chamber fate assignment. Together, our studies uncover a new role for BMP signaling in the regulation of chamber size, supporting a model in which differential reception of cardiac inductive signals establishes chamber proportion.

Size and function of the atria

Size and function of the atria

Long-Term Effects of the Maze Procedure on Atrial Size and Mechanical Function

The Maze procedure is effective in restoring sinus rhythm, but the extensive procedure may have negative effects on atrial mechanical function. Decreased atrial contractility has been observed early after the Maze procedure. The purpose of this study was to determine the long-term effect of the Maze procedure on atrial size and mechanical function. Fifty-two patients with symptomatic atrial fibrillation, without structural heart or valvular disease, underwent the Cox Maze III procedure. Atrial size and mechanical function were assessed by echocardiographic examination at baseline and postoperatively at a mean +/- SD of 6 +/- 1 and 56 +/- 12 months. The left atrial area was decreased 6 months after the procedure compared with baseline (mean, 15.4 +/- 3.3 vs 17.6 +/- 3.2 cm2, p < 0.01). By 56 months, however, the left atrial area had increased compared with the 6-month follow-up (19.5 +/- 3.9 vs 15.4 +/- 3.3 cm2, p < 0.001), resulting in no difference in left atrial size compared with the baseline values. The left atrial contractility, measured as fractional area change, was significantly reduced at 6 and 56 months of follow-up (0.20 +/- 0.09 and 0.19 +/- 0.07 vs baseline 0.36 +/- 0.09), as was the transmitral A-wave velocity (30 +/- 12 and 28 +/- 8 cm/s vs baseline 40 +/- 15). The same pattern was seen for the right atrium. This study shows that the Maze procedure results in a sustained decrease in atrial contractility. The initial reduction in atrial size is later reversed. These findings contradict late improvements in atrial mechanical function after Maze surgery and may have important implications for the risk of thromboembolic complications.

Simplified technique for surgical ligation of the left atrial appendage in high-risk patients

Simplified technique for surgical ligation of the left atrial appendage in high-risk patients