Rypko J. Beukema

Ablation of focal atrial tachycardia from the non-coronary aortic cusp: case series and review of the literature

AIMS Focal atrial tachycardia successfully ablated from the non-coronary cusp (NCC) is rare. Our aim was to describe the characteristics of mapping and ablation therapy of NCC focal atrial tachycardias and to provide a comprehensive review of the literature. METHODS AND RESULTS Seven patients (age 40 ± 9 years) with symptomatic, drug-refractory atrial tachycardia were referred for electrophysiological study. Extensive right and left atrial mapping revealed atrial tachycardia near His in all patients but either failed to identify a successful ablation site or radiofrequency applications only resulted in temporary termination of the tachycardia. Mapping and ablation of the NCC were performed retrogradely via the right femoral artery. Mapping of the NCC demonstrated earliest atrial activation during atrial tachycardia 38 ± 14 ms (ranging 17-56 ms) before the onset of the P-wave. Earliest atrial activation in the NCC was earlier than earliest activation in the right atrium and left atrium in all patients. The P-wave morphology was predominantly negative in the inferior leads and biphasic in leads V1 and V2. The tachycardia was successfully terminated by radiofrequency application in 10 ± 6 s (2-16 s), without complications. All patients were free of symptoms during a follow-up of 19 ± 9 months. Literature search revealed 18 reports (91 patients) describing NCC focal atrial tachycardia, with 99% long-term ablation success with a 1% complication rate. CONCLUSION Symptomatic focal atrial tachycardia near His may originate from the NCC and can be treated safely and effectively with radiofrequency ablation.

Electrophysiological effects of acute atrial stretch on persistent atrial fibrillation in patients undergoing open heart surgery

BACKGROUND The electrophysiologic effects of acute atrial dilatation and dedilatation in humans with chronic atrial fibrillation remains to be elucidated. OBJECTIVE To study the electrophysiological effects of acute atrial dedilatation and subsequent dilatation in patients with long-standing persistent atrial fibrillation (AF) with structural heart disease undergoing elective cardiac surgery. METHODS Nine patients were studied. Mean age was 71 ± 10 years, and left ventricular ejection was 46% ± 6%. Patients had at least moderate mitral valve regurgitation and dilated atria. After sternotomy and during extracorporal circulation, mapping was performed on the beating heart with 2 multielectrode arrays (60 electrodes each, interelectrode distance 1.5 mm) positioned on the lateral wall of the right atrium (RA) and left atrium (LA). Atrial pressure and size were altered by modifying extracorporal circulation. AF electrograms were recorded at baseline after dedilation and after dilatation of the atria afterward. RESULTS At baseline, the median AF cycle length (mAFCL) was 184 ± 27 ms in the RA and 180 ± 17 ms in the LA. After dedilatation, the mAFCL shortened significantly to 168 ± 13 ms in the RA and to 168 ± 20 ms in the LA. Dilatation lengthened mAFCL significantly to 189 ± 17 ms in the RA and to 185 ± 23 ms in the LA. Conduction block (CB) at baseline was 14.3% ± 3.6% in the RA and 17.3% ± 5.5% in the LA. CB decreased significantly with dedilatation to 7.4% ± 2.9% in the RA and to 7.9% ± 6.3% in the LA. CB increased significantly with dilatation afterward to 15.0% ± 8.3% in the RA and to 18.5% ± 16.0% in the LA. CONCLUSIONS Acute dedilatation of the atria in patients with long-standing persistent AF causes a decrease in the mAFCL in both atria. Subsequent dilatation increased the mAFCL. The amount of CB decreased with dedilatation and increased with dilatation afterward in both atria.

Atrial fibrillation after but not before primary angioplasty for ST-segment elevation myocardial infarction of prognostic importance.

AimIn patients with ST-segment elevation myocardial infarction (STEMI), it is uncertain whether atrial fibrillation has prognostic implications. There may be a difference between atrial fibrillation before and after reperfusion therapy.Methods and resultsIn patients with STEMI treated with primary percutaneous coronary intervention (PCI), ECGs were analysed before and after primary PCI. Of the 1623 patients with electrocardiographic data before primary PCI, 53 patients (3.3%) had atrial fibrillation. Patients with atrial fibrillation were older, were more often female, and less often had anterior MI location. Of the 1728 patients with electrocardiographic data after primary PCI, 52 patients (3.0%) had atrial fibrillation. Atrial fibrillation was more common in older patients and in those with Killip class >1. Also patients with occlusion of the right coronary artery or TIMI flow 0 before primary PCI more commonly had AF after the procedure. Not successful reperfusion was also associated with a higher incidence of AF after primary PCI. Although both atrial fibrillation before and after primary PCI were associated with increased mortality, multivariable analyses, adjusting for differences in age, gender and Killip class on admission, revealed that atrial fibrillation after PCI (OR 3.69, 95% CI 1.87–7.29) but not before PCI (OR 1.86, 95% CI 0.89–3.90) was independent and statistically significantly associated with long-term mortality.ConclusionIn patients with STEMI, atrial fibrillation after but not before primary PCI has independent prognostic implications. Possibly, atrial fibrillation after the PCI is a symptom of failed reperfusion and a sign of heart failure.

Association of serial high sensitivity troponin T with onset of atrial fibrillation in ST elevation myocardial infarction patients undergoing primary percutaneous coronary intervention

Aims: Previous reports claimed that high sensitivity troponin T (HsTnT) is not associated with atrial fibrillation (AF) in the setting of acute ST-elevation myocardial infarction (STEMI) and primary percutaneous coronary intervention. However, the association of serial HsTnT levels and new-onset AF is unknown. We therefore assessed the temporal association between HsTnT levels and post-infarction AF. Methods and results: 830 patients enrolled in On-TIME II were included. HsTnT was assessed at baseline, and 24h and 72h after admission for STEMI. New-onset AF episodes were divided into three subgroups: AF during the first 24h of admission, AF 24–72h after admission and AF >72h after admission. ROC analysis and binary logistic regression were performed. Mean age was 62±12 years and 76% were male. Seventy-three patients developed new-onset AF: 41 patients developed AF during the first 24h of admission, 14 patients developed AF 24–72h after admission and 18 patients developed AF >72h after admission. HsTnT at baseline was associated with new-onset AF (area under curve (AUC) 0.596, p=0.008), but not with AF during the first 24h of admission (AUC: 0.539, p=0.414). HsTnT after 24h (AUC 0.792, p=0.001) and after 72h (AUC: 0.884, p<0.001) were associated with AF 24–72h and >72h after admission. HsTnT after 24h and 72h were stronger predictors of AF compared with HsTnT at baseline. In regression analysis, age (odds ratio 1.056, p<0.001), Killip Class >1 (odds ratio: 2.694, p=0.010) and HsTnT after 24h (odds ratio: 1.012, p=0.017) and after 72h (odds ratio: 1.035, p<0.001) showed the strongest association with post-infarction AF. Conclusion: Serial HsTnT plasma levels are associated with post-infarction, new-onset AF.

Catheter ablation of symptomatic postoperative atrial arrhythmias after epicardial surgical disconnection of the pulmonary veins and left atrial appendage ligation in patients with atrial fibrillation

OBJECTIVES Minimally invasive thoracoscopic epicardial pulmonary vein isolation (MIPI) has an important role in the surgical treatment of atrial fibrillation (AF). However, the management of recurrent atrial arrhythmias after MIPI and long-term success rate of catheter ablation have not been well studied. METHODS Electrophysiological study was performed in 23 patients, 378 ± 282 days after MIPI surgery, because of recurrent symptomatic atrial arrhythmias. RESULTS A total of 20 patients presented with paroxysmal and persistent AF, 2 patients had a combination of AF and atrial tachycardia (AT) and 1 patient had a combination of AF and atrial flutter. All patients showed pulmonary vein (PV) reconnection. ATs were micro-re-entry PV-related ATs and atrial flutter was cavotricuspid isthmus dependent. Eighteen of 23 patients (78.3%) were free of atrial arrhythmias after one catheter ablation procedure at a mean follow-up of 50 ± 16 months. Three patients underwent a second ablation procedure for recurrent AF and macro-re-entry left atrial flutter. Eventually 20 of 23 patients (87%) remained free of atrial arrhythmias after a mean of 1.1 ± 0.3 ablation procedures. CONCLUSIONS Catheter ablation of recurrent atrial arrhythmias following MIPI for paroxysmal and persistent AF is a feasible and effective treatment with a good long-term success rate. Reconnection of PVs accounts for most recurrences.

The KHENERGY Study: Safety and Efficacy of KH176 in Mitochondrial m.3243A>G Spectrum Disorders

KH176 is a potent intracellular reduction–oxidation‐modulating compound developed to treat mitochondrial disease. We studied tolerability, safety, pharmacokinetics, pharmacodynamics, and efficacy of twice daily oral 100 mg KH176 for 28 days in a double‐blind, randomized, placebo‐controlled, two‐way crossover phase IIA study in 18 adult m.3243A>G patients without cardiovascular involvement. Efficacy parameters included clinical and functional outcome measures and biomarkers. The trial was registered within ClinicalTrials.gov (NCT02909400), the European Clinical Trials Database (2016‐001696‐79), and ISRCTN (43372293) (The KHENERGY study). Twice daily oral 100 mg KH176 was well tolerated and appeared safe. No serious treatment‐emergent adverse events were reported. No significant improvements in gait parameters or other outcome measures were obtained, except for a positive effect on alertness and mood, although a coincidence due to multiplicity cannot be ignored. The results of the study provide first data on safety and efficacy of KH176 in patients with mitochondrial disease and will be instrumental in designing future clinical trials.

Serial N-Terminal Pro Brain Natriuretic Peptide Assessments in PredictingNew-Onset Atrial Fibrillation in ST Elevation Myocardial InfarctionPatients who Undergo Primary Percutaneous Coronary Intervention

Background: N-terminal pro-Brain Natriuretic Peptide(NT-proBNP)is associated with atrial fibrillation(AF) in the setting of acute ST-elevation myocardial infarction (STEMI), and the present study was aimed at assessing the temporal association between NT-proBNP and incident AF. Methods: 830 patients enrolled in On-TIME II were included. NT-proBNP was assessed at baseline, 24 h and 72 h after admission for STEMI. Patients with new-onset AF 72 h after admission. NT-proBNP serum levels at the three assessment intervals was used to predict the timing of AF with a receiver-operator characteristic, and a binary logistic model was created to predict the AF at the various timings. Results: Mean age was 62 ±12 years and 76% were male. 73 patients developed incident AF, 41 developed AF on admission, 14 patients developed AF 24-72 h after admission and 18 patients developed AF >72 h after admission. NT-proBNP at baseline (area under curve (AUC) 0.657, P<0.001), after 24 h (AUC 0.829, P<0.001) and after 72 h (AUC 0.891, P<0.001) predicted AF. However, NT-proBNP at baseline did not predict AF on admission (AUC 0.591, P=0.058). NT-proBNP after 24 h and 72 h were stronger predictors of AF compared to NT-proBNP at baseline. In regression analysis, NT-proBNP after 24 h (OR:1.220, P<0.001) and 72 h (OR:1.290, P<0.002) showed a significant association with postinfarction AF. Conclusion: This study shows serial NT-proBNP plasma level assessments enhance risk stratification for incident AF in STEMI patients.