Unraveling the interplay: early-stage atrial functional mitral regurgitation and left atrial electrical substrate in atrial fibrillation patients.

Background: Atrial fibrillation (AF) triggers atrial remodeling, impacting atrial function and ablation efficacy. This remodeling leads to atrial cardiomyopathy and dilatation, linked to mitral regurgitation, forming atrial functional mitral regurgitation (aFMR). Our study explores the relationship between early-stage-aFMR and the atrial electrical architecture, focusing on left atrial bipolar voltage and low-voltage areas (LVAs) in AF patients. Methods: We enrolled 282 patients undergoing redo-PVI after AF recurrence post-PVI. Echocardiography was performed prior to ablation, and only patients with no, mild, or mild-to-moderate aFMR were included. Ablation used radiofrequency and a 3D mapping system, with atrial voltage documented on each atrial wall. LVAs were calculated using high-density maps, and patients were followed for 15 months. Results: Significant differences in left atrial voltage and LVA extent were observed based on aFMR severity. Patients with aFMR 1 + had significantly lower atrial voltage compared to no-aFMR, but no significant increase in LVAs. Patients with aFMR 2 + showed lower voltage amplitudes in all atrial regions and larger LVAs compared to no-aFMR patients. AF recurrence was significantly higher in the aFMR group (62.9% vs. 48.3%, p = 0.027) within 1 year. aFMR was associated with AF recurrence after adjusting for sex, age, and AF types (HR: 1.517, 95% CI: 1.057-2.184, p = 0.025). Conclusion: aFMR in AF patients may indicate progressive atrial remodeling and left atrial cardiomyopathy, characterized by reduced atrial voltage and increased LVAs. aFMR is linked to PVI outcomes, suggesting its consideration in AF therapy decision-making.

Coronary sinus signal amplitude: A predictor of the atrial substrate and low voltage areas.

BACKGROUND: Low voltage areas (LVA) are pivotal in atrial fibrillation (AF) pathogenesis, influencing local left atrial LA excitation and perpetuating AF occurrences. While pulmonary vein isolation (PVI) with cryo-balloon (CB) ablation is effective for AF, it doesn't provide insights into the LA substrate or detect LVA, which affects ablation success rates. This study examines whether LA voltage and LVAs can be anticipated by analyzing the voltage signal amplitude at the coronary sinus (CS) catheter, which is standard in CB and radiofrequency ablation procedures. METHODS: A retrospective analysis of 284 patients with recurrent AF undergoing RF catheter ablation was conducted at a high-volume EP center in Germany. The correlation between LA voltage and LVA with the CS signal was explored. RESULTS: The signal amplitude in the CS significantly correlated with voltage in LA walls, particularly in the proximal CS (correlation coefficient ρ = 0.81, p < 0.001). A CS signal cut-off of 1.155 mV effectively predicted severe atrial LVAs (>40%) with a sensitivity of 90.7% and a specificity of 100%. While a threshold of 1.945 mV identified patients with no significant atrial LVAs (<5%) with a sensitivity of 88% and a specificity of 50% (AUC: 0.81, 95% CI: 0.71-0.89, p < 0.001). CONCLUSION: The CS signal amplitude is associated with the LA voltage. Due to its potential as a diagnostic tool for atrial LVAs, the signal amplitude in the CS could provide valuable information about the LA substrate, especially when 3D mapping is not feasible.

Catheter-directed thrombolysis guided by pulmonary artery pressure registration in pulmonary embolism: a case report.

Background: Duration and dosage of thrombolysis for ultrasound-assisted catheter-directed thrombolysis (UACDT) in patients with intermediate high-risk pulmonary embolism remain controversial and treatment protocols vary. Case summary: A 58-year-old female patient suffered from a right-sided urolithiasis. The clinical course was complicated by an intermediate high-risk pulmonary embolism [pulmonary embolism severity index (PESI) score 108 points and simplified PESI ≥1] with bilateral proximal thrombus and significant right heart dysfunction. The pulmonary embolism response team (PERT) made a decision towards UACDT. The standard duration of UACDT ranges between 6 and 15 h depending on clinical parameters. In this particular case, the clinical parameters such as heart rate (no tachycardia) or oxygen saturation (chronic obstructive pulmonary disease) might lead to premature termination of UACDT. Therefore, PERT decided to additionally monitor pulmonary artery pressure (PAP) continuously during the UACDT via a separate pigtail catheter in the pulmonary artery. Ultrasound-assisted catheter-directed thrombolysis was performed using 1 mg/h recombinant tissue plasminogen activator (rtPA) per catheter, while PAP was registered continuously. Heart rate and oxygen saturation remained unchanged during UACDT. However, after 6 h of UACDT, systolic PAP decreased slightly from 62 to 55 mmHg and therapy was prolonged to 15 h. Pulmonary artery pressure dropped to 46 mmHg after 15 h. The patient was discharged from hospital at Day 7, and echocardiography revealed no signs of right heart dysfunction. Discussion: Dosage of the thrombolysis agent and duration of UACDT are still a matter of debate. Besides clinical parameters and transthoracic echocardiography, invasive real-time PAP monitoring during UACDT could facilitate important information for therapy guidance in selected cases.

Optimizing fibrosis detection: a comparison of electroanatomical mapping and late enhancement gadolinium magnetic resonance imaging.

BACKGROUND: Fibrotic atrial cardiomyopathy plays an important role in determining the outcome of ablation in patients with atrial fibrillation (AF). Two main methods are being used for the evaluation of fibrosis: voltage-based high-density (HD) electroanatomical mapping (EAM) and late gadolinium enhancement MRI (LGE-MRI). The comparability between both methods in detecting fibrosis has not been systematically investigated. METHODS: LGE-MRIs of the left atrium (LA) were performed in 21 patients. LA-fibrosis was evaluated using a custom-designed software generating a 3D-model of the LA. HD-electroanatomical maps were recorded in each patient. After processing the maps and the MRI models by excluding the mitral valve, pulmonary veins, and the left atrial appendage, the LGE areas were measured and compared to the low voltage areas (LVA) in the HD maps using three different cutoff values of 0.5 mV, 0.7 mV, and 1.0 mV. RESULTS: The analysis revealed significant differences between EAM and LGE-MRI in assessing LA-fibrosis at 0.5-mV (for anterior and posterior walls) and 1.0-mV cutoffs (for anterior and posterior wall and septum). However, no significant differences were found between EAM and LGE-MRI when using a 0.7-mV cutoff for all the investigated areas. CONCLUSIONS: A voltage cutoff of 0.7 mV provided the best correlation between EAM and LGE MRI for detecting left atrial fibrosis. It supports the idea that a 0.5-mV cutoff may underestimate fibrosis, as areas with local signal voltages between 0.6 and 0.8 mV could also show LGE on MRI. Further research is needed to determine the ideal voltage cutoff for detecting left atrial fibrosis.

Clinical significance of the rivaroxaban-dronedarone interaction: insights from physiologically based pharmacokinetic modelling.

Patients with atrial fibrillation may require rhythm control therapy in addition to anticoagulation therapy for the prevention of stroke. Since 2012, the European Society of Cardiology and European Heart Rhythm Association guidelines have recommended non-vitamin K antagonist oral anticoagulants, including rivaroxaban, for the prevention of stroke in patients with atrial fibrillation. During the same period, these guidelines have also recommended dronedarone or amiodarone as second-line rhythm control agents in certain patients with atrial fibrillation and no contraindications. Amiodarone and dronedarone both strongly inhibit P-glycoprotein, while dronedarone is a moderate and amiodarone a weak inhibitor of cytochrome P450 3A4 (CYP3A4). Based on these data and evidence from physiologically based pharmacokinetic modelling, amiodarone and dronedarone are expected to have similar effects on rivaroxaban exposure resulting from P-glycoprotein and CYP3A4 inhibition. However, the rivaroxaban label recommends against the concomitant use of dronedarone, but not amiodarone, citing a lack of evidence on the concomitant use of rivaroxaban and dronedarone as the reason for the different recommendations. In this report, we discuss evidence from clinical studies and physiologically based pharmacokinetic modelling on the potential for increased rivaroxaban exposure resulting from drug-drug interaction between rivaroxaban and dronedarone or amiodarone. The current evidence supports the same clinical status and concomitant use of either amiodarone or dronedarone with rivaroxaban, which could be considered in future recommendations.

Fast anatomical mapping of the carina and its implications for acute pulmonary vein isolation.

BACKGROUND: Fast anatomical mapping (FAM) of the left atrium and pulmonary veins (PV) during PV isolation (PVI) generates anatomical information about the carina region additionally. We aimed to investigate the utility of these data in relation to conduction abilities of the intervenous carina. METHODS: We investigated 71 patients with drug-refractory atrial fibrillation (AF) who underwent first-time circumferential PVI using an electroanatomical mapping system. Carina width between ipsilateral PV was measured using FAM and an integrated distance measurement tool. Encirclings were divided into carina ablation and noncarina ablation groups based on the necessity of carina ablation to achieve PVI. RESULTS: In total, 142 encirclings were analyzed and first-pass isolation was observed in 102 (72%) encirclings. Nonfirst-pass PVI solely due to a gap on the line or persistent carina conduction was observed in 10 (7%) and 30 (21%) encirclings, respectively. Encirclings were classified into a carina ablation group (n = 30, 21%) and noncarina ablation group (n = 112, 79%). Carina width was significantly larger in the carina ablation vs nonarina ablation group (right: 11.9 ± 1.5 mm vs 8 ± 1.4 mm, P < .001/left: 12.1 ± 1.3 mm vs 8.1 ± 1.1 mm, P < .001) requiring additional carina ablation. CONCLUSION: Carina-related PV conduction is a common finding after the first-pass ablation during PVI. Measurement of carina width using FAM is feasible and its value correlates with the necessity of carina ablation to achieve PVI.

Diagnostic role of coronary CT angiography in paroxysmal or first diagnosed atrial fibrillation.

OBJECTIVES: The presence of coronary artery disease (CAD) in patients hospitalised with paroxysmal or first diagnosed atrial fibrillation (AF) has major implications for antithrombotic therapy and cardiovascular event rate. Coronary CT angiography (CCTA) is a feasible tool to identify patients with concealed CAD. We aimed to evaluate the diagnostic role of early CCTA in patients hospitalised with paroxysmal or first diagnosed AF. METHODS: In a 5-year single-centre retrospective analysis, 566 patients with paroxysmal or first diagnosed AF who underwent CCTA were enrolled to investigate the presence of CAD. RESULTS: In patients with paroxysmal or first diagnosed AF, CCTA revealed CAD (coronary artery stenosis ≥50%) in 39.2%. Cardiac catheterisation was performed in 31.6%, confirming CAD in 13.1% of all patients. In 8.0% percutaneous coronary intervention and in 0.5% coronary artery bypass grafting was performed. In patients with paroxysmal or first diagnosed AF: (1) angina pectoris per se does not predict CAD; (2) multivariable regression analysis revealed age, male sex and diabetes as risk factors for CAD in AF; (3) Framingham Risk Score for coronary heart disease and CHA2DS2-VASc-Score were relevant risk scores of CAD and (4) the classification of Coronary Artery Calcium score reference values according to the Multi-Ethnic Study of Atherosclerosis was a predictor of CAD. CONCLUSION: Patients with paroxysmal or first diagnosed AF are at risk for CAD, while CCTA is a feasible diagnostic tool for CAD. We recommend to integrate CT calcium scoring and CCTA into the diagnostic workup of patients with new-onset or paroxysmal AF.

Case Report: Living on the Edge-Transcatheter Mitral Valve Repair Related Infective Endocarditis.

Background: Infective endocarditis (IE) following mitral valve edge-to-edge repair is a rare complication with high mortality. Case summary: A 91-year-old male patient was admitted to intensive care unit with sepsis due to urinary tract infection after insertion of a urinary catheter by the outpatient urologist. Two weeks ago, the patient was discharged from hospital after successful transcatheter edge-to-edge mitral valve repair (TEER) using a PASCAL Ace device. The initially withdrawn blood revealed repeatedly Proteus mirabilis bacteremia as causal for the sepsis due to urinary tract infection. An antibiotic regime with Ampicillin/Sulbactam was initiated and discontinued after 7 days. During the clinical course the patient again developed fever and blood cultures again revealed P. mirabilis. In transesophageal echocardiography (TOE), IE of the PASCAL Ace device was confirmed by a vegetation accompanied by a mild to moderate mitral regurgitation. While the patient was stable at this time and deemed not suitable for cardiac surgery, the endocarditis team made a decision toward a prolonged 6-week antibiotic regime with an antibiotic combination of Ampicillin 2 g qds and Ciprofloxacin 750 mg td. Due to posterior leaflet perforation severe mitral regurgitation developed while PASCAL Ace vegetations were significantly reduced by the antibiotic therapy. Therefore, the patient underwent successful endoscopic mitral valve replacement. Another 4 weeks of antibiotic treatment with Ampicillin 2 g qds followed before the patient was discharged. Discussion: P. mirabilis is able to form biofilms, resulting in a high risk for endocarditis following transcatheter mitral valve repair especially when device endothelization is incomplete. Endoscopic mitral valve replacement could serve as a bailout strategy in refractory Clip-endocarditis.

Long-term impact of a bonus freeze on clinical outcome: Analysis of effective and non-effective bonus freezes in cryoballoon ablation.

PURPOSE: Data on bonus freeze characteristics and their impact on complication rates and long-term clinical outcome are limited. METHODS: Pulmonary vein isolation (PVI) using a 28 mm 2nd-generation cryoballoon (CB) was performed in 169 patients (pts). The isolation temperatures, time to isolation and minimal temperatures of the cryoapplications were documented. RESULTS: The study included 92 pts who received one bonus freeze after PVI in group I and 77 pts who did not receive a bonus freeze in group II. After a mean follow-up time of 19.0±8.6 months in group I and 16.4±7.5 months in group II, 67 of 92 pts (72.8%) and 49 of 75 pts available to follow up (65.3%; p = 0.221) were free of atrial tachyarrhythmia, respectively. Phrenic nerve palsy occurred in 5.4% of the pts in group I (5/92 pts) and 1.3% of the pts in group II (1/77 pts; p = 0.22). Both the mean nadir temperatures of the bonus freezes and mean nadir temperatures of the isolation freezes differed significantly between the recurrent and non-recurrent pts in group I. The predilection sites of the reconduction for both groups were the inferior aspect of the inferior pulmonary veins. CONCLUSION: The impact of a bonus freeze on long-term clinical outcome was not significant for two reasons: 1) The necessity of a bonus freeze was low because the long-term clinical success rate without a bonus freeze was high; and 2) the majority of bonus freezes, especially at the predilection sites, such as the inferior PV, appeared to be ineffective.