Pulmonary Vein Isolation in Elderly Patients ≥ 75 Years: A Propensity Score-Matched Analysis With Focus on Differences Among Atrial Fibrillation Types.

BACKGROUND: Age is a major risk factor for development of atrial fibrillation (AF) and associated with increased recurrence rates in the setting of rhythm control. Current data tend to support catheter ablation in elderly patients, but uncertainties exist regarding efficacy and safety of ablation in elderly patients. METHODS: This was a prospective single-centre observational study with propensity score matching (PSM) to investigate the influence of age on efficacy and safety of cryoballoon ablation (CBA) stratified by age (< 75 years vs ≥ 75 years) and AF phenotype (paroxysmal vs persistent). Primary efficacy endpoint was recurrence of atrial arrhythmia after a 90-day blanking period. Safety endpoints were death, stroke, or procedure-associated complications. RESULTS: Consecutive patients (n = 953) underwent CBA for first-time AF ablation. Median follow-up was 18 months. By means of PSM, 268 matches were formed. At 1 year, primary efficacy endpoint occurred in 22.4% of young vs 33.2% of elderly patients, including both AF phenotypes (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.47-0.90; P = 0.01). AF relapse occurred in 19.7% of young vs 28.5% of elderly patients with paroxysmal (HR, 0.63; 95% CI, 0.40-0.99; P = 0.046) compared with 25.9% (30 of 116, young) vs 38.8% (45 of 116, elderly) patients with persistent AF (HR, 0.62; 95% CI, 0.39-0.97; P = 0.038). No difference was observed regarding the incidence of safety endpoints between young and elderly patients (P = 0.38). CONCLUSIONS: CBA is associated with higher recurrence rates in elderly (≥ 75 years) than in younger patients, with highest recurrence rates in elderly patients with persistent AF.

Zero-fluoro atrioventricular-nodal reentrant tachycardia ablation.

BACKGROUND: Atrioventricular-nodal reentrant tachycardia (AVNRT) is a common supraventricular tachycardia, particularly in younger patients. The treatment of choice is radiofrequency catheter ablation (RFCA), traditionally necessitating ionizing radiation for catheter guidance. OBJECTIVE: The authors aimed to demonstrate the feasibility and safety of zero-fluoroscopy RFCA of AVNRT using EnSite™ NavX™ as a three-dimensional (3D) electroanatomical mapping system (EAM). METHODS: The authors retrospectively analyzed 68 patients that underwent AVNRT-RFCA. One group was a priori allocated to conventional fluoroscopy mapping (convFluoro, n = 30). In 38 cases, the electrophysiologist chose to use 3D-EAM for ablation. Of these patients, 20 could be ablated without fluoroscopy use (zeroFluoro). In 18 cases that were initially intended as 3D-EAM, additional fluoroscopy use was necessary due to difficult anatomic conditions (convertedFluoro). Procedure duration, fluoroscopy duration and dose, as well as complications were analyzed. RESULTS: Procedure duration was similar for the convFluoro and zeroFluoro groups (74 ± 24 min vs. 80 ± 26 min, p = ns). The convertedFluoro group showed longer procedure duration compared to the convFluoro group (94 ± 30 min vs. 74 ± 24 min, p < 0.05). The use of 3D-EAM significantly reduced fluoroscopy duration comparing the convFluoro with the convertedFluoro group (12 ± 9 min vs. 7 ± 6 min, p < 0.05). The difference in fluoroscopy dose between convFluoro and convertedFluoro did not reach significance (169 ± 166 cGycm2 vs. 134 ± 137 cGycm2, p = ns). In zeroFluoro cases, no radiation was used at all. 3D-EAM-guided RFCA was primarily successful in all patients. Overall, there were only few minor complications in the different groups. No major complications occurred. CONCLUSION: Zero-fluoro RFCA in patients with AVNRT is feasible and safe. 3D-EAM can reduce radiation exposure in the majority of patients without prolonging procedure duration or increasing complications.

Cryoballoon pulmonary vein isolation for atrial fibrillation in obese patients: A non-inferiority analysis.

Background: Patients with obesity are at higher risk of developing atrial fibrillation (AF) and benefit from radiofrequency ablation. Potentially, cryoballoon ablation (CBA) may be equally effective and safe in such patients. Methods: We conducted a prospective, single-center study to investigate whether CBA for pulmonary vein isolation is as effective and safe in obese patients as it is in non-obese controls. Primary efficacy endpoint was recurrence of AF, atrial flutter or atrial tachycardia after a 90-day blanking period. Safety endpoints were death, stroke or procedure-associated complications. Conduction of a subgroup analysis regarding the impact of additional diabetes was predefined in case the primary efficacy endpoint was met. The study was event driven and powered for noninferiority. Results: A total of 949 patients underwent CBA (251 obese with mean body-mass-index 33.5 ± 3 kg/m2 and 698 non-obese with mean body-mass-index 25.3 ± 3 kg/m2) during a 5-year recruitment period. Median follow-up was 15 months. The primary efficacy endpoint occurred in 78/251 obese and 247/698 non-obese patients (12-months Kaplan-Meier event-rate estimates, hazard ratio 0.79; 95% confidence interval [CI], 0.58 to 1.07; log-rank P = 0.0002 for noninferiority). No differences were observed in safety end point occurrence (P = 0.78). The occurrence of primary efficacy end point was found to be unaffected by the presence of diabetes in the prespecified subgroup analysis (log-rank P = 0.57). Conclusion: CBA is effective and safe in obese and DM patients. Weighing the high cardiovascular risk of obese patients against a reduction of cardiovascular events by early rhythm control, CBA should be offered to this patient population.

Frame-rate reduction to reduce radiation dose for cardiac device implantation is safe.

Background: Radiation exposure to patient and surgeon during cardiac implantable electrical device (CIED) procedures remains a substantial health hazard to date. Advanced technical options for radiation dose reduction often pose considerable financial hurdles. We propose a near-zero cost, low-effort modification to a clinical x-ray system significantly reducing radiation dose during CIED implantation. Objective: We aim to evaluate a reduced frame rate protocol in CIED implantation for complication rates and reduction in radiation exposure. Methods: Starting May 2019, the frame rate during CIED implantations at our hospital was halved from 7.5 frames/s to 3.8 frames/s, and no further technical changes were made. During the following year, 264 patients were operated using this protocol and retrospectively compared with 231 cases implanted in the year before the protocol change, totaling 495 cases. Of these, 17%, 63%, and 19% were single-chamber, dual-chamber, or resynchronization devices, respectively. Incidence of complication prior to hospital discharge was considered the primary endpoint of the analysis. Radiation dose and procedural parameters were secondary endpoints. Results: There was no increase in complications with the reduced frame rate protocol. Regression analysis further supported that the reduced frame rate radiation protocol was not associated with complication rates. Radiation exposure measured as dose area product was significantly reduced by ∼62% (median 369 [interquartile range 154-1207] cGy·cm2 via the reduced frame rate protocol vs median 970 [interquartile range 400-1906] cGy·cm2 with the standard frame rate; P < 0.01). Conclusion: A reduction of frame rate during CIED implantation is safe in terms of complication incidence and effective in terms of reducing radiation exposure.

Impact of cryoballoon application abortion due to phrenic nerve injury on reconnection rates: a YETI subgroup analysis.

AIMS: Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an effective treatment for atrial fibrillation (AF). The most frequent complication during CB-based PVI is right-sided phrenic nerve injury (PNI) which is leading to premature abortion of the freeze cycle. Here, we analysed reconnection rates after CB-based PVI and PNI in a large-scale population during repeat procedures. METHODS AND RESULTS: In the YETI registry, a total of 17 356 patients underwent CB-based PVI in 33 centres, and 731 (4.2%) patients experienced PNI. A total of 111/731 (15.2%) patients received a repeat procedure for treatment of recurrent AF. In 94/111 (84.7%) patients data on repeat procedures were available. A total of 89/94 (94.7%) index pulmonary veins (PVs) have been isolated during the initial PVI. During repeat procedures, 22 (24.7%) of initially isolated index PVs showed reconnection. The use of a double stop technique did non influence the PV reconnection rate (P = 0.464). The time to PNI was 140.5 ± 45.1 s in patients with persistent PVI and 133.5 ± 53.8 s in patients with reconnection (P = 0.559). No differences were noted between the two populations in terms of CB temperature at the time of PNI (P = 0.362). The only parameter associated with isolation durability was CB temperature after 30 s of freezing. The PV reconnection did not influence the time to AF recurrence. CONCLUSION: In patients with cryoballon application abortion due to PNI, a high rate of persistent PVI rate was found at repeat procedures. Our data may help to identify the optimal dosing protocol in CB-based PVI procedures. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT03645577?term=YETI&cntry=DE&draw=2&rank=1 ClinicalTrials.gov Identifier: NCT03645577.

Persistent Atrial Fibrillation in Elderly Patients: Limited Efficacy of Pulmonary Vein Isolation.

(1) Background: Cryoballoon pulmonary vein isolation (cryoPVI) is established for symptomatic paroxysmal atrial fibrillation (AF) treatment, but its value in persistent AF is less clear. In particular, limited data are available on its efficacy in elderly patients (≥75 years) with persistent AF. Age is an important modifier of AF progression and represents a risk-factor for AF recurrence. (2) Methods: Prospective, single-center observational study to evaluate the impact of age on efficacy and safety of cryoPVI in elderly patients. Primary efficacy endpoint was symptomatic AF recurrence after 90-day blanking period. Primary safety endpoints were death from any cause, procedure-associated complications or stroke/transient ischemic attack. Median follow-up was 17 months (range 3−24). (3) Results: We included 268 patients with persistent AF (94 ≥ 75 years of age). Multivariate Cox regression analysis identified age as the only independent factor influencing AF recurrence in the overall cohort (p = 0.006). To minimize confounding bias in efficacy and safety analysis of cryoPVI, we matched younger and elderly patients with respect to baseline characteristics. At 24 months, primary efficacy endpoint occurred in 13/69 patients <75 years and 31/69 patients ≥75 years of age (24 months Kaplan−Meier event-rate estimates, HR 0.34; 95% CI, 0.19 to 0.62; log-rank p = 0.0004). No differences were observed in the occurrence of safety end points. (4) Conclusions: Elderly (≥75 years) patients with persistent AF undergoing cryoPVI had an approximately threefold higher risk of symptomatic AF recurrence than matched younger patients. Accordingly, other treatment modalities may be evaluated in this population.

Process optimization for atrial fibrillation ablation.

AIMS: In the light of an increasing prevalence of atrial fibrillation (AF) and growing evidence for the superiority of early invasive rhythm control, the demand for ablation therapy is rising. Accordingly, ablation centres will have to maximize their capacity by either adding electrophysiology laboratory resources or optimizing process management. In order to optimize process management, we applied "Lean Six Sigma" method to a single ablation center. We compared procedural parameters, acute efficacy and safety of cryoballoon pulmonary vein isolation (cryoPVI) before and after modifications. METHODS AND RESULTS: Patients (n = 713) undergoing cryoPVI (108 before and 605 after process optimization) were analysed. Within 3 years of process optimization, electrophysiology laboratory occupancy time (150.7 ± 44.4 vs. 94 ± 22.1 min, P < 0.001), procedure time (84.5 ± 21-47.4 ± 12 min, P < 0.001), left-atrial dwell time (53.9 ± 18.4-31.9 ± 9.9 min, P < 0.001), and fluoroscopy time (15.8 ± 5.1 vs. 6.2 ± 2.8 min, P < 0.001) decreased. Contrast dye use (116 ± 35 vs. 27 ± 15 mL, P < 0.001) and radiation dose (893 ± 1078 vs. 253 ± 249 cGy cm2, P < 0.001) were reduced by ∼77 and ∼72%, respectively. There was no difference in safety endpoint occurrence (3.7 vs. 1.5%, P = 0.11). CONCLUSION: The process optimization of cryoPVI for AF therapy using the 'Lean Six Sigma' method significantly increases efficiency without compromising patient safety.

Prospective randomized trial of skin closure for pacemaker implantation: absorbable vs. non-absorbable suture : PRO-PACE.

BACKGROUND: Pacemaker implantations have been performed for > 50 years, reaching 1.25 million implants worldwide per year. Despite this, only few randomized studies exist regarding technical aspects of the implantation procedure-in particular, wound closure. Accordingly, the authors compared absorbable vs. non-absorbable suture regarding wound healing. METHODS: Consecutive patients scheduled for de novo pacemaker implantation without defibrillation therapy were prospectively randomized into two groups: non-absorbable (Prolene®, Ethicon Inc.) or absorbable suture (Monocryl®, Ethicon Inc.). The wound was systematically assessed for cosmetic outcome at 1 day, 6 weeks, and 1 year post implantation using the patient and observer scar assessment scale (POSAS). Adverse events noted included bleeding, pocket hematoma, infection, suture insufficiency, and revision surgery. RESULTS: A total of 114 patients (mean age: 79 ± 10 years, n = 60 male) were randomized into the two groups. Of these, 105 completed follow-up (lost to follow-up: 7.9%). Groups were comparable for clinical characteristics or use of oral anticoagulants. There was no difference in cosmetic outcome and incidence of adverse events at any follow-up visit. POSAS scores were: 1 day: 1.4 ± 0.4 vs. 1.3 ± 0.4, P = 0.44, 6 weeks: 1.4 ± 0.6 vs. 1.4 ± 0.7, P = 0.57; 1 year: 1.4 ± 1.4 vs. 2.1 ± 3, P = 0.60. No pocket hematoma or infection occurred in either group. No additional surgery was necessary for local findings. Retrospectively, scar development was straight in the Prolene® group and slightly wavy with Monocryl®. CONCLUSION: Suture material does not influence wound healing as represented by the cosmetic result and the occurrence of adverse events. The choice of suture material used should be left to the physician's discretion.

Telemedical cardiac risk assessment by implantable cardiac monitors in patients after myocardial infarction with autonomic dysfunction (SMART-MI-DZHK9): a prospective investigator-initiated, randomised, multicentre, open-label, diagnostic trial.

BACKGROUND: Cardiac autonomic dysfunction after myocardial infarction identifies patients at high risk despite only moderately reduced left ventricular ejection fraction. We aimed to show that telemedical monitoring with implantable cardiac monitors in these patients can improve early detection of subclinical but prognostically relevant arrhythmic events. METHODS: We did a prospective investigator-initiated, randomised, multicentre, open-label, diagnostic trial at 33 centres in Germany and Austria. Survivors of acute myocardial infarction with left ventricular ejection fraction of 36-50% had biosignal analysis for assessment of cardiac autonomic function. Patients with abnormal periodic repolarisation dynamics (≥5·75 deg2) or abnormal deceleration capacity (≤2·5 ms) were randomly assigned (1:1) to telemedical monitoring with implantable cardiac monitors or conventional follow-up. Primary endpoint was time to detection of serious arrhythmic events defined by atrial fibrillation 6 min or longer, atrioventricular block class IIb or higher and fast non-sustained (>187 beats per min; ≥40 beats) or sustained ventricular tachycardia or fibrillation. This study is registered with ClinicalTrials.gov, NCT02594488. FINDINGS: Between May 12, 2016, and July 20, 2020, 1305 individuals were screened and 400 patients at high risk were randomly assigned (median age 64 years [IQR 57-73]); left ventricular ejection fraction 45% [40-48]) to telemedical monitoring with implantable cardiac monitors (implantable cardiac monitor group; n=201) or conventional follow-up (control group; n=199). During median follow-up of 21 months, serious arrhythmic events were detected in 60 (30%) patients of the implantable cardiac monitor group and 12 (6%) patients of the control group (hazard ratio 6·33 [IQR 3·40-11·78]; p<0·001). An improved detection rate by implantable cardiac monitors was observed for all types of serious arrhythmic events: atrial fibrillation 6 min or longer (47 [23%] patients vs 11 [6%] patients; p<0·001), atrioventricular block class IIb or higher (14 [7%] vs 0; p<0·001) and ventricular tachycardia or ventricular fibrillation (nine [4%] patients vs two [1%] patients; p=0·054). INTERPRETATION: In patients at high risk after myocardial infarction and cardiac autonomic dysfunction but only moderately reduced left ventricular ejection fraction, telemedical monitoring with implantable cardiac monitors was highly effective in early detection of subclinical, prognostically relevant serious arrhythmic events. FUNDING: German Centre for Cardiovascular Research (DZHK) and Medtronic Bakken Research Center.

Phrenic Nerve Injury During Cryoballoon-Based Pulmonary Vein Isolation: Results of the Worldwide YETI Registry.

BACKGROUND: Cryoballoon-based pulmonary vein isolation (PVI) has emerged as an effective treatment for atrial fibrillation. The most frequent complication during cryoballoon-based PVI is phrenic nerve injury (PNI). However, data on PNI are scarce. METHODS: The YETI registry is a retrospective, multicenter, and multinational registry evaluating the incidence, characteristics, prognostic factors for PNI recovery and follow-up data of patients with PNI during cryoballoon-based PVI. Experienced electrophysiological centers were invited to participate. All patients with PNI during CB2 or third (CB3) and fourth-generation cryoballoon (CB4)-based PVI were eligible. RESULTS: A total of 17 356 patients underwent cryoballoon-based PVI in 33 centers from 10 countries. A total of 731 (4.2%) patients experienced PNI. The mean time to PNI was 127.7±50.4 seconds, and the mean temperature at the time of PNI was -49±8°C. At the end of the procedure, PNI recovered in 394/731 patients (53.9%). Recovery of PNI at 12 months of follow-up was found in 97.0% of patients (682/703, with 28 patients lost to follow-up). A total of 16/703 (2.3%) reported symptomatic PNI. Only 0.06% of the overall population showed symptomatic and permanent PNI. Prognostic factors improving PNI recovery are immediate stop at PNI by double-stop technique and utilization of a bonus-freeze protocol. Age, cryoballoon temperature at PNI, and compound motor action potential amplitude loss >30% were identified as factors decreasing PNI recovery. Based on these parameters, a score was calculated. The YETI score has a numerical value that will directly represent the probability of a specific patient of recovering from PNI within 12 months. CONCLUSIONS: The incidence of PNI during cryoballoon-based PVI was 4.2%. Overall 97% of PNI recovered within 12 months. Symptomatic and permanent PNI is exceedingly rare in patients after cryoballoon-based PVI. The YETI score estimates the prognosis after iatrogenic cryoballoon-derived PNI. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03645577. Graphic Abstract: A graphic abstract is available for this article.

Impact of the COVID-19 pandemic on cardiovascular mortality and catherization activity during the lockdown in central Germany: an observational study.

AIMS: During the COVID-19 pandemic, hospital admissions for cardiac care have declined. However, effects on mortality are unclear. Thus, we sought to evaluate the impact of the lockdown period in central Germany on overall and cardiovascular deaths. Simultaneously we looked at catheterization activities in the same region. METHODS AND RESULTS: Data from 22 of 24 public health-authorities in central Germany were aggregated during the pandemic related lockdown period and compared to the same time period in 2019. Information on the total number of deaths and causes of death, including cardiovascular mortality, were collected. Additionally, we compared rates of hospitalization (n = 5178) for chronic coronary syndrome (CCS), acute coronary syndrome (ACS), and out of hospital cardiac arrest (OHCA) in 26 hospitals in this area. Data on 5,984 deaths occurring between March 23, 2020 and April 26, 2020 were evaluated. In comparison to the reference non-pandemic period in 2019 (deaths: n = 5832), there was a non-significant increase in all-cause mortality of 2.6% [incidence rate ratio (IRR) 1.03, 95% confidence interval (CI) 0.99-1.06; p = 0.16]. Cardiovascular and cardiac mortality increased significantly by 7.6% (IRR 1.08, 95%-CI 1.01-1.14; p = 0.02) and by 11.8% (IRR 1.12, 95%-CI 1.05-1.19; p < 0.001), respectively. During the same period, our data revealed a drop in cardiac catherization procedures. CONCLUSION: During the COVID-19-related lockdown a significant increase in cardiovascular mortality was observed in central Germany, whereas catherization activities were reduced. The mechanisms underlying both of these observations should be investigated further in order to better understand the effects of a pandemic-related lockdown and social-distancing restrictions on cardiovascular care and mortality.

[Supraventricular tachycardia - ECG interpretation and clinical management]. / Vorgehen und Behandlungsoptionen bei supraventrikulären Tachykardien.

Supraventricular tachycardia (SVT) is a very common cause of hospital admission and its diagnostic and treatment may be difficult sometimes. While vagal maneuvers or intravenous adenosis administration during 12-lead ECG recording should be performed in hemodynamically stable patients for diagnosis and treatment, hemodynamically unstable patients should be carioverted immediately. The new ESC guideline (2019) on diagnosis and clinical management of SVT significantly upgrades catheter ablation and gives it a new preferential status. For example, in patients with symptomatic recurrence, atrioventricular nodal re-entrant tachycardia should be ablated due to the very low risk of AV block. Furthermore, catheter ablation should also be offered as first-line therapy to patients with reentrant and focal arrhythmias. The diagnosis and therapy of tachycardiomyopathy is of particular importance and treatment should incorporate the ablation of the underlying supraventricular tachycardia. The therapy of supraventricular tachycardia during pregnancy should be free of antiarrhythmic medication, especially in the first trimester. If ablation is necessary during pregnancy, only fluoroscopy-free mapping systems should be used. This review covers aspects of ECG diagnosis and guideline-based treatment of SVT.

[Unusual complication during pacemaker implantation]. / Ungewöhnliche Komplikation einer Schrittmacherimplantation.

Bradycardic arrhythmias have a broad spectrum of symptoms which range from mild dizziness to cardiac syncope. Pacemaker therapy continues to be the cornerstone of treatment and can effectively treat symptoms. Despite an implanted cardiac pacemaker, patients may experience continued or even new symptoms. We report on a 73-year-old woman with postoperative new palpitations due to a very rare intraoperative complication.

Percutaneous transluminal renal angioplasty of global kidney ischemia improves renal function and blood pressure.

BACKGROUND: Renal artery stenosis (RAS) can lead to hypertension and renal failure. Nevertheless, its treatment by percutaneous transluminal renal angioplasty (PTRA) remains controversial. It is unknown, whether patients with global kidney ischemia (GKI), that means patients with bilateral RAS or RAS with a single functioning kidney, may benefit from PTRA or not. METHODS: We retrospectively analyzed 93 patients with RAS (25 bilateral or single functioning kidney) undergoing PTRA. Patients had refractory hypertension (≥3 medications). Blood pressure, antihypertensive drugs and serum-creatinine were compared pre-/post-intervention and at 1 year's follow-up. RESULTS: At 1 year after PTRA of patients with GKI, systolic and diastolic blood pressure were significantly reduced compared to patients with unilateral PTRA (systolic: -19.1 ± 10.5 [bilateral] vs. -11.4 ± 12.1 mmHg [unilateral], P < 0.01; diastolic: -10.1 ± 6.8 mmHg vs. -6.3 ± 6.6 mmHg, P < 0.05). The number of antihypertensive drugs was reduced by -0.8 ± 3.0 at 1 year in patients with GKI, while it increased by +0.1 ± 3.5 in the unilateral RAS group (P < 0.001). Furthermore, post-interventional serum-creatinine decreased by -34.6 ± 31.4 µmol/I after of patients with GKI (P < 0.001 vs. baseline). In patients with unilateral PTRA, a non-significant increase in serum-creatinine was observed (+8.3 ± 2 µmol/l). CONCLUSION: PTRA in patients with GKI led to improved blood pressure and renal function. A large, well-designed, randomized clinical trial targeting this population is still needed. The benefit of PTRA should be measured with the risks in each patient individually.

Acupuncture at the auricular branch of the vagus nerve enhances heart rate variability in humans: An exploratory study.

BACKGROUND: Recent animal and human studies have shown antiarrhythmic effects inhibiting inducibility of atrial fibrillation through low-level transcutaneous electrical stimulation at the auricular branch of the vagus nerve (ABVN). OBJECTIVE: The present study investigated effects of acupuncture at the ABVN on the autonomic cardiac nervous system in humans through analysis of heart rate and heart rate variability (HRV) parameters. METHODS: We enrolled 24 healthy male volunteers and compared acupuncture at the ABVN to placebo-acupuncture performed at the Ma-35 point (an acupuncture point used in traditional Chinese medicine to treat pain caused by gonarthrosis). An additional measurement without acupuncture served as control. We analyzed the following heart rate and HRV parameters: standard deviation of normal-to-normal intervals (SDNN), root mean square of successive R-R interval differences (RMSSD), high frequency (HF), low frequency (LF), LF/HF ratio. RESULTS: In comparison to placebo acupuncture, acupuncture at the ABVN led to a significant reduction in heart rate (approximately 4%-6%, P < .05) and an increase in overall HRV demonstrated by SDNN (approximately 19%, P < .05). RMSSD and power spectral density parameters (HF, LF, LF/HF) showed statistical trends (P < .1) induced by auricular acupuncture in favor of vagal tone. No relevant difference was shown between control and placebo group. CONCLUSION: Acupuncture of the region innervated by the ABVN may activate the parasympathetic nervous system, as suggested by reduction in heart rate and increase in SDNN. However, given the lack of clear significant changes in other HRV parameters, this effect seems modest and its evaluation requires further investigation.

Age-related regulation and region-specific distribution of ion channel subunits promoting atrial fibrillation in human left and right atria.

AIMS: Age-induced changes and electrical remodelling are important components of the atrial fibrillation (AF) substrate. To study regional distribution and age-dependent changes in gene expression that may promote AF in human atria. METHODS AND RESULTS: Human left atrial (LA) and right atrial (RA) tissue samples were obtained from donor hearts unsuitable for transplantation and from patients undergoing mitral valve repair. Atrial fibrillation was mimicked in vitro by tachypacing of human atrial tissue slices. Ionic currents were studied by the whole-cell patch-clamp technique; gene expression was analysed by real-time qPCR and immunoblotting. Both healthy RA and RA from older patients showed greater CACNA1c mRNA and CaV1.2 protein expression than LA. No age-dependent changes of Kir2.1 expression in both atria were seen. Remodelling occurred in a qualitatively similar manner in RA and LA. IK1 and Kir2.1 protein expression increased with AF. MiR-1, miR-26a, and miR-26b were down-regulated with AF in both atria. ICa,L was decreased. CACNA1c and CACNA2b expression decreased and miR-328 increased in RA and LA during AF. Ex vivo tachypacing of human atrial slices replicated these findings. There were age-dependent increases in miR-1 and miR-328, while miR-26a decreased with age in atrial tissues from healthy human donor hearts. CONCLUSION: Features of electrical remodelling in man occur in a qualitatively similar manner in both human atria. Age-related miR-328 dysregulation and reduced ICa,L may contribute to increased AF susceptibility with age.