-
International Journal of Molecular... May 2024The high incidence of atrial fibrillation (AFib) following cardiac surgery (postoperative atrial fibrillation, POAF) relies on specific surgical features. However, in...
The high incidence of atrial fibrillation (AFib) following cardiac surgery (postoperative atrial fibrillation, POAF) relies on specific surgical features. However, in the setting of POAF, the role of the microbiome in the modulation of cardiac fibrosis is still not clear. This study aimed to analyze the effect of the microbiome and its main metabolic product (trimethylamine-N-oxide, TMAO) in the fibrosis of myocardial tissue, to investigate its role in POAF. Patients undergoing elective cardiac surgery with cardiopulmonary bypass, central atrio-caval cannulation and no history of AFib, were included. A fragment of the right atrium was analyzed for qualitative and mRNA-quantitative evaluation. A preoperative blood sample was analyzed with enzyme-linked immunosorbent assay (ELISA). A total of 100 patients have been included, with POAF occurring in 38%. Histologically, a higher degree of fibrosis, angiogenesis and inflammation has been observed in POAF. Quantitative evaluation showed increased mRNA expression of collagen-1, collagen-3, fibronectin, and transforming growth factor beta (TGFb) in the POAF group. ELISA analysis showed higher levels of TMAO, lipopolysaccharide and TGFb in POAF, with similar levels of sP-selectin and zonulin. TMAO ≥ 61.8 ng/mL (odds ratio, OR 2.88 [1.35-6.16], = 0.006), preoperative hemoglobin < 13.1 g/dL (OR 2.37 [1.07-5.24], = 0.033) and impaired right ventricular function (OR 2.38 [1.17-4.83], = 0.017) were independent predictors of POAF. Also, TMAO was significantly associated with POAF by means of increased fibrosis. Gut microbiome product TMAO is crucial for myocardial fibrosis, which is a key factor for POAF. Patients in preoperative sinus rhythm who will develop POAF have increased genetic expression of pro-fibrotic genes and enhanced fibrosis in histological staining. Elevated TMAO level (≥61.8 ng/mL) is an independent risk factor for POAF.
Topics: Humans; Atrial Fibrillation; Male; Female; Gastrointestinal Microbiome; Aged; Fibrosis; Middle Aged; Myocardium; Postoperative Complications; Methylamines
PubMed: 38892223
DOI: 10.3390/ijms25116037 -
Journal of Thoracic Disease May 2024Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice, which leads to cardiac decompensation, cardiovascular and cerebrovascular... (Review)
Review
BACKGROUND AND OBJECTIVE
Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice, which leads to cardiac decompensation, cardiovascular and cerebrovascular infarction, and other thromboembolic diseases. AF is one of the most common comorbidities of valvular heart disease, especially in mitral valve disease. At the time of their mitral valve surgery, 20-42% of patients have AF. It is beneficial to maintain postoperative sinus rhythm and minimize complications when AF surgery is performed concurrently with mitral valve surgery. This review describes the surgical management of AF in mitral valve surgery, including AF surgical route, surgical ablation technology and surgical approaches. The aim of this review is to enable more patients with AF to receive more appropriate and individualised treatment.
METHODS
A narrative review was conducted on the literature on PubMed, Embase including all relevant studies published until November 2023.
KEY CONTENT AND FINDINGS
This review focuses on the surgical management of AF during mitral valve surgery, including AF surgical route, surgical ablation technology and surgical approaches.
CONCLUSIONS
Mitral valve surgery combined with AF surgery facilitates the maintenance of postoperative sinus rhythm in patients, reduces the risk of postoperative stroke, and improves survival. Advances in ablation technology have reduced the difficulty of the procedure, making it possible for more patients to undergo surgical ablation. In the future, it will be possible to tailor specific lesion sets and ablation modalities for individual patients. This would make surgical treatment of AF more effective and applicable to a larger population of patients with AF and mitral valve disease.
PubMed: 38883625
DOI: 10.21037/jtd-23-1984 -
Cureus May 2024Atrial fibrillation (AF) represents the most prevalent cardiac arrhythmia globally, with a significant burden on mortality and morbidity. While rhythm control...
BACKGROUND
Atrial fibrillation (AF) represents the most prevalent cardiac arrhythmia globally, with a significant burden on mortality and morbidity. While rhythm control strategies, particularly electrical cardioversion (EC), have gained traction in recent years, the precise impact of sinus rhythm (SR) restoration on cardiac reverse remodeling remains a subject of debate.
METHODS
In this study, 23 AF patients underwent elective EC. AF diagnosis was made via ECG by a cardiologist, and candidates for cardioversion were selected by an electrophysiologist. Transthoracic echocardiography (TTE) by utilizing two-dimensional, three-dimensional, and tissue Doppler imaging modalities was performed before cardioversion. Patients who maintained SR after six months underwent a second TTE evaluation.
RESULTS
SR was restored successfully in all 23 patients and 15 patients (65.2%) maintained SR after six months. SR group had significantly lower baseline cardiac output (CO) and indexed left ventricular end-systolic volume (LVESVi), and better European Heart Rhythm Association (EHRA) scores after six months. Within the SR group, patients exhibited significant changes in mitral regurgitation, tricuspid regurgitation, EHRA score, LVESVi, stroke volume, left ventricle ejection fraction, left ventricle global longitudinal strain, indexed minimum left atrial volume, left atrial emptying fraction, and left and right atrial diameters. Reduced CO was associated with AF recurrence. Receiver operating curve analysis revealed that CO value can predict six-month AF recurrence with a cut-off point of 2.3.
CONCLUSION
Our study underscores the beneficial effects of SR restoration on cardiac parameters in AF patients post EC. Notably, CO value emerged as a predictor of AF recurrence, emphasizing the importance of comprehensive assessments for predicting long-term outcomes.
PubMed: 38883085
DOI: 10.7759/cureus.60504 -
Journal of Interventional Cardiac... Jun 2024The innovative peak frequency mapping facilitates the quantification of electrogram sharpness. However, reference values for normal atrial tissue are currently...
BACKGROUND
The innovative peak frequency mapping facilitates the quantification of electrogram sharpness. However, reference values for normal atrial tissue are currently undefined. In this study, we explored the distribution of peak frequency and omnipolar peak-to-peak voltage (V-max) in a normal heart.
METHODS
Twenty-two patients with structurally normal heart were included. Either the right atrium (RA) and superior vena cava (SVC) or the left atrium (LA) and pulmonary veins (PVs) were mapped during sinus rhythm.
RESULTS
In total, 13,654 points in the RA and 4143 points in the SVC from 15 patients and 4662 points in the LA and 2761 points in PVs from 7 patients were analyzed. The correlation between peak frequency and V-max was weak (R = 0.223). The median peak frequency was larger in the SVC than in the RA (441 [358-524] Hz vs. 358 [291-441] Hz, P < 0.0001) and in PVs than in the LA (346 [253-441] Hz vs. 323 [262-397] Hz, P < 0.0001). Conversely, the median V-max was smaller in the SVC than in the RA (1.96 [0.77-3.75] mV vs. 4.11 [2.10-6.83] mV, P < 0.0001) and in PVs than in the LA (1.16 [0.33-3.17] mV vs. 4.42 [2.63-6.84] mV, P < 0.0001). More than 95% of peak frequencies were > 174 Hz in the RA and > 185 Hz in the LA, and > 95% of V-maxes were > 0.52 and > 1.07 mV in the RA and LA, respectively.
CONCLUSION
Given the limited correlation between peak frequency and V-max, and recognizing their potential to provide distinct information, they can be used complementarily. Employing these parameters to extract varied insights can provide comprehensive understandings of tissue characteristics.
PubMed: 38880852
DOI: 10.1007/s10840-024-01845-4 -
Heart Rhythm Jun 2024It remains unclear what causes symptoms in patients with paroxysmal atrial fibrillation (AF).
BACKGROUND
It remains unclear what causes symptoms in patients with paroxysmal atrial fibrillation (AF).
OBJECTIVE
This study aimed to correlate the magnitudes of the skin sympathetic nerve activity (SKNA) with symptoms in patients with AF.
METHODS
We prospectively enrolled patients with symptomatic paroxysmal AF for ambulatory electrocardiogram and SKNA recording. Heart rhythms at time of symptoms were categorized as AF or normal sinus rhythm (NSR). Maximal and average SKNA (aSKNA) and heart rate (HR) were compared between symptomatic and asymptomatic AF and NSR episodes using mixed effects models to account for within-patient correlations.
RESULTS
Among the 31 enrolled patients, 16 (52%) had at least one episode of AF, and 24 (77%) endorsed symptoms during the monitoring period. Compared with asymptomatic AF episodes, symptomatic AF episodes had higher maximal aSKNA (1.260 [IQR 1.114-1.723] μV vs. 1.108 [IQR 0.974-1.312] μV, p<0.001) and higher maximal HR (152±24 bpm vs. 132±19 bpm, p<0.001). Symptomatic NSR episodes were associated with higher maximal aSKNA (1.612 [IQR 1.287-2.027] μV vs. 1.332 [IQR 1.033-1.668] μV, p=0.001) and higher maximal HR (152±24 bpm vs. 105±16 bpm, p<0.001) than asymptomatic NSR episodes. Of the symptomatic episodes, 66 (73%) occurred during NSR and 24 (27%) during AF. All p-values were obtained from mixed effects models.
CONCLUSION
Symptomatic episodes in patients with paroxysmal AF were more frequently associated with NSR than AF. Symptomatic AF and NSR episodes were associated with higher aSKNA than asymptomatic episodes. In patients with paroxysmal AF, symptoms correlate better with SKNA than heart rhythm.
PubMed: 38880203
DOI: 10.1016/j.hrthm.2024.06.015 -
Pediatric Cardiology Jun 2024There is renewed interest in septation of the double-inlet ventricle as an alternative to Fontan palliation. We examined our septation experience with over 30 years of...
There is renewed interest in septation of the double-inlet ventricle as an alternative to Fontan palliation. We examined our septation experience with over 30 years of follow-up. We retrospectively reviewed patients with double-inlet ventricle from 1990 to 2011. Patients with two adequate atrioventricular valves, a volume-overloaded ventricle, and no significant subaortic obstruction were septation candidates. Of 98 double-inlet ventricle patients, 9 (9.2%) underwent attempted septation via a one-stage (n = 2, 22.2%) or two-stage (n = 7, 77.8%) approach. Ages at primary septation were 7.5 and 20.2 months. In the staged group, median age at the first and second stage was 8.3 months [range 4.1-14.7] and 22.4 months [range 11.4-195.7], respectively. There were no operative mortalities. Median follow-up was 18.8 years [range 0.4-32.9] and 30-year transplant-free survival was 77.8% ± 13.9%. Both single stage patients are alive and in sinus rhythm; 1 underwent bilateral outflow tract obstruction repair 27 years later. Of 7 patients planned for two-stage septation, there was 1 interval mortality and 1 deferred the second stage. Five patients underwent the second stage; 1 required early reintervention for a residual neo-septal defect and 1 underwent right atrioventricular valve replacement 28 years later. Three patients required a pacemaker preoperatively (n = 1) or after partial septation (n = 2). At latest follow-up, 7 patients have normal biventricular function and no significant valvulopathy. All remain NYHA functional class I. Select double-inlet ventricles may be septated with excellent long-term outcomes. Reconsideration of this strategy is warranted to avoid the sequelae of Fontan circulation.
PubMed: 38879596
DOI: 10.1007/s00246-024-03510-z -
JACC. Clinical Electrophysiology May 2024Purkinje fibers play an important role in initiation and maintenance of ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PMVT). Fascicular...
BACKGROUND
Purkinje fibers play an important role in initiation and maintenance of ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PMVT). Fascicular substrate modification (FSM) approaches have been suggested to treat recurrent VF in case reports and small case series.
OBJECTIVES
The aim of this study was to investigate outcomes of catheter-based FSM to treat VF and PMVT.
METHODS
Of 2,212 consecutive patients with ventricular arrhythmia undergoing catheter ablation, 18 (0.81%) underwent FSM of the Purkinje fibers as identified with high-density mapping during sinus rhythm. Fascicular substrate and VF initiation were mapped using a multipolar catheter. The endpoint of the ablation was noninducibility of VF and PMVT. In select patients, remapping revealed elimination of the targeted Purkinje potentials. Demographic, clinical, and follow-up characteristics were prospectively collected in our institutional database.
RESULTS
A total of 18 patients (mean age 56 ± 3.8 years, 22% women) were included in the study. Of those, 11 (61.1%) had idiopathic VF, 3 (16.7%) had nonischemic cardiomyopathy, and 4 (22.2%) had mixed cardiomyopathy. The average left ventricular ejection fraction was 42.5%. At least 2 antiarrhythmic drugs had failed preablation. At baseline, all patients had inducible VF or PMVT. At the end of the procedure, no patient demonstrated new evidence of fascicular block or bundle branch block. There were no procedure-related complications. After a median follow-up period of 24 months, 16 patients (88.9%) were arrhythmia free on or off drugs: 11 of 11 patients (100%) with idiopathic VF vs 5 of 7 patients (71.4%) with underlying cardiomyopathy (P = 0.06).
CONCLUSIONS
Catheter ablation of human VF and PMVT with FSM is feasible and safe and appears highly effective, with high rates of acute VF noninducibility and long-term freedom from recurrent VF.
PubMed: 38878012
DOI: 10.1016/j.jacep.2024.03.035 -
Clinical Cardiology Jun 2024The ambulatory arterial stiffness index (AASI) is an indirect measure of blood pressure variability and arterial stiffness which are atrial fibrillation (AF) risk... (Observational Study)
Observational Study
BACKGROUND
The ambulatory arterial stiffness index (AASI) is an indirect measure of blood pressure variability and arterial stiffness which are atrial fibrillation (AF) risk factors. The relationship between AASI and AF development has not been previously investigated and was the primary aim of this study.
METHODS
This was an observational cohort study of adults (aged 18-85 years) in sinus rhythm, who underwent 24-h ambulatory blood pressure monitoring (ABPM) for the diagnosis of hypertension or its control.
RESULTS
Eight hundred and twenty-one patients (49% men) aged 58.7 ± 15.3 years were followed up for a median of 4.0 years (3317 patient-years). In total, 75 patients (9.1%) developed ≥1 AF episode during follow-up. The mean AASI was 0.46 ± 0.17 (median 0.46). AASI values (0.52 ± 0.16 vs. 0.45 ± 0.17; p < .001) and the proportion of AASI values above the median (65.3% vs. 48.4%; p = .005) were greater among the patients who developed AF versus those that did not respectively. AASI significantly correlated with age (r = .49; 95% confidence interval: 0.44-0.54: p < .001). On Kaplan-Meier analysis, higher baseline AASI by median, tertiles, and quartiles were all significantly associated with AF development (X: 10.13; p < .001). On Cox regression analyses, both a 1-standard deviation increase and AASI > median were independent predictors of AF, but this relationship was no longer significant when age was included in the model.
CONCLUSIONS
AASI is an independent predictor of AF development. However, this relationship becomes insignificant after adjustment for age which is higher correlated with AASI.
Topics: Humans; Atrial Fibrillation; Middle Aged; Male; Female; Aged; Adult; Blood Pressure Monitoring, Ambulatory; Vascular Stiffness; Risk Factors; Aged, 80 and over; Adolescent; Incidence; Young Adult; Hypertension; Blood Pressure; Risk Assessment; Time Factors; Predictive Value of Tests; Follow-Up Studies; Retrospective Studies
PubMed: 38873860
DOI: 10.1002/clc.24299 -
Frontiers in Medicine 2024BRASH syndrome is a vicious cycle of hyperkalemia and bradycardia and is an under-recognized life-threatening clinical diagnosis. It is usually initiated by hypovolemia...
BRASH syndrome is a vicious cycle of hyperkalemia and bradycardia and is an under-recognized life-threatening clinical diagnosis. It is usually initiated by hypovolemia or hyperkalemia. We report here on the case of a 92-year-old man with hypertension and heart failure who presented to the emergency department with weakness following diarrhea. He was on amlodipine, benazepril, metoprolol, furosemide and spironolactone. The patient's blood pressure was 88/53 mmHg and the serum creatinine was 241 μmol/L. Within 2 h, the patient's heart rate decreased from 58 beats per minute to 26 beats per minute, and serum potassium levels gradually increased from 6.07 mmol/L to 7.3 mmol/L. The electrocardiogram showed a junctional escape rhythm with accidental sinus capture. The diagnosis of BRASH syndrome was made based on clinical symptoms, a biochemical profile and the results of an electrocardiogram. The patient was rapidly stabilized with the administration of intravenous calcium gluconate, dextrose and insulin, 5% sodium bicarbonate, 0.9% sodium chloride, furosemide, and oral zirconium cyclosilicate. Sinus rhythm at a heart rate of 75 bpm was detected 5 h later, along with normal serum potassium levels. After 2 weeks, kidney function returned to normal. Clinicians should be alert to patients with hyperkalemia and maintain a high index of suspicion for BRASH syndrome. Timely diagnosis and comprehensive intervention are critical for better outcomes in managing patients with BRASH.
PubMed: 38873207
DOI: 10.3389/fmed.2024.1405494 -
Anatolian Journal of Cardiology Jun 2024Atrial fibrillation (AF) and heart failure (HF) are prevalent cardiovascular conditions in East Asia, with a complex interrelationship. The directionality of the causal...
BACKGROUND
Atrial fibrillation (AF) and heart failure (HF) are prevalent cardiovascular conditions in East Asia, with a complex interrelationship. The directionality of the causal impact of AF on HF risk remains uncertain. This study employs Mendelian randomization (MR) to investigate the potential causal effect of AF on HF.
METHODS
Utilizing summary data from genome-wide association studies (GWAS) within the Medical Research Council Integrative Epidemiology Unit open GWAS database, we analyzed 8180 AF cases and 28 612 controls, alongside 9413 HF cases and 203 040 controls, all of East Asian descent. We conducted MR analysis using the inverse variance weighted (IVW) method, complemented by various sensitivity analyses, including bidirectional MR to assess causality in the reverse direction.
RESULTS
Genetically predicted AF was found to be causally associated with an increased risk of HF in East Asian populations (odds ratio = 1.14, 95% CI: 1.10-1.19, P <.001) as per the IVW method. These findings were consistent across multiple MR methods. Sensitivity analyses revealed no significant heterogeneity or pleiotropy. Notably, bidirectional MR analysis showed no causal effect of HF on the risk of developing AF.
CONCLUSIONS
The MR analysis supports a unidirectional causal relationship between AF and increased HF risk in East Asian individuals. The absence of a reverse causal effect reinforces the importance of maintaining sinus rhythm to mitigate HF risk. Further research is warranted to corroborate these findings and to explore their clinical implications in depth.
PubMed: 38872495
DOI: 10.14744/AnatolJCardiol.2024.4369