Repeat cryoablation as a redo procedure for atrial fibrillation ablation: Is it a good choice?

BACKGROUND: Ablation of atrial fibrillation (AF), both cryoablation ablation (CBA) and radiofrequency catheter ablation (RFCA), have demonstrated to be safe and effective. About 1 in 3 patients may face a redo due to recurrence and the best technique is unknown. The aim of this study is to assess the efficacy of CBA as a repeat procedure in patients with prior CBA or RFCA. METHODS: A nation-wide CBA registry (RECABA) was analyzed and patients were compared who had previously undergone CBA (Prior-CB) or RFCA (Prior-RF). The primary endpoint was AF recurrence at 12 months after a 3-month blanking period. A survival analysis was performed, univariate and multivariate Cox models were also built. RESULTS: Seventy-four patients were included. Thirty-three (44.6%) were in the Prior-CB group and 41 (55.4%) in the Prior-RF. There were more reconnected pulmonary veins in the Prior-RF than in Prior-CB group (40.4% vs.16.5%, p = 0.0001). The 12-month Kaplan-Meier estimate of freedom from AF recurrence after the blanking period was 61.0% (95% confidence interval [CI] 41.4-75.8%) in the Prior-CB, and 89.2% (95% CI 73.6-95.9%) in the Prior-RF group (p = 0.002). Multivariate Cox regression pointed Prior-CB as the sole independent predictor of AF recurrence, with an adjusted HR of 2.67 (95% CI 1.05-6.79). CONCLUSIONS: Repeat CBA shows higher rates of AF recurrences compared to CBA after a previous RFCA despite presenting less reconnected veins at the procedure. These data suggest that patients with AF recurrence after CBA may benefit from other ablation techniques after a recurrence. RECABA is registered at clinicaltrials.gov with the Unique Identifier NCT02785991.

Multimodality Imaging in the Study of the Left Atrium.

The left atrium (LA) plays a vital role in maintaining normal cardiac function. Many cardiac diseases involve the functioning of the LA directly or indirectly. For this reason, the study of the LA has become a priority for today's imaging techniques. Assessment of LA size, function and wall characteristics is routinely performed in cardiac imaging laboratories when a patient undergoes transthoracic echocardiography. However, in cases when the LA is the focus of disease management, such as in atrial fibrillation or left atrial appendage closure, the use of multimodality is critical. Knowledge of the usefulness of each cardiac imaging technique for the study of LA in these patients is crucial in order to choose the most appropriate treatment. While echocardiography is the most widely performed technique for its evaluation and the study of wall deformation analysis is increasingly becoming more reliable, multidetector computed tomography allows a detailed analysis of its anatomy to be carried out in 3D reconstructions that help in the approach to interventional treatments. In addition, the evaluation of the wall by cardiac magnetic resonance imaging or the generation of electroanatomical maps in the electrophysiology room have become essential tools in the treatment of multiple atrial pathologies. For this reason, the goal of this review article is to describe the basic anatomical and functional information of the LA as well as their study employing the main imaging techniques currently available, so that practitioners specializing in cardiac imaging techniques can use these tools in an accurate and clinically useful manner.

Merged two-way mapping technique: an alternative 3D electroanatomical mapping approach to guide challenging ablation procedures of accessory pathways with bidirectional conduction properties.

BACKGROUND: Catheter ablation of accessory pathways (AP) with bidirectional conduction may be challenging due to issues related to anatomical course or location. OBJECTIVE: We describe an alternative electro-anatomical mapping technique which aims at depicting the entire anatomic course of the AP from the atrial toward the ventricular insertion in order to guide catheter ablation. METHODS: Twenty consecutive patients with confirmed bidirectional AP conduction and at least one previous ablation procedure or para-Hisian location were included. 3-D electro-anatomical mapping was used to depict the merged 10-ms isochrone area of maximum early activation of both the ventricular and atrial signals during sinus rhythm and ventricular pacing/orthodromic tachycardia, respectively. Catheter ablation was performed within the depicted earliest isochrone area. RESULTS: Acute bidirectional AP conduction block was achieved in all patients 4.2 ± 1.7 s after the first radiofrequency energy pulse was delivered, without reconnection during a 30 ± 10 min post-ablation observation time. No procedural complications were seen. After a mean follow-up period of 9 ± 7 months (range 3 to 16), no recurrences were documented. CONCLUSION: This merged two-way mapping technique is a safe, efficient, and effective technique for ablation of APs with bidirectional conduction.

Cardiac Resynchronization Therapy Response Is Equalized in Men and Women by Electrical Optimization: PR Matters.

OBJECTIVES: This study hypothesized that the shorter intrinsic PR interval observed in women allows a greater degree of fusion with intrinsic conduction, achieving a shorter QRS interval duration and, thus, a better response. BACKGROUND: Women benefit more from cardiac resynchronization therapy (CRT) than men. However, the reason for this difference remains elusive. METHODS: A cohort of 180 patients included in the BEST (Fusion based optimization in resynchronization therapy [ECG Optimization of CRT: Evaluation of Mid-Term Response]; NCT01439529) study were retrospectively analyzed. Patients were initially randomized to either nonoptimized CRT (NON-OPT group; n = 89) or electrocardiographically optimized CRT based on the fusion-optimized intervals (FOI) method (FOI group; n = 91). Echocardiographic response was defined as a >15% decrease in left ventricular end-systolic volume at the 12-month follow-up. RESULTS: The basal PR interval was shorter in women as compared to men. In the NON-OPT group, CRT resulted in a shorter paced QRS interval in women than in men (134 ± 21 ms vs. 151 ± 21 ms, respectively; p = 0.003, 95% confidence interval [CI]: -27 to -5.6) and better response in women than in men: 70.4% vs. 46.4%, respectively (odds ratio: 0.37; p = 0.04; 95% CI: 0.14 to 0.97). There were no differences in paced QRS interval duration (126 ± 13 ms vs. 129 ± 17 ms; p = 0.47) or response between women and men in the FOI group (68% vs. 70.5%; odds ratio: 1.12; p = 0.82; 95% CI: 0.41 to 3.07). FOI extended the atrioventricular interval to obtain the best fusion; the atrioventricular intervals tended to require greater extension in men than in women (22 ± 33 ms vs. 8 ± 28 ms, respectively; p = 0.07). CONCLUSIONS: Women had a shorter PR interval, which was associated with a shorter QRS interval and better response to CRT. The difference in QRS interval duration and response between men and women did not persist when CRT was optimized using fusion with intrinsic conduction (FOI programming).

Reduction in new cardiac electronic device implantations in Catalonia during COVID-19.

AIMS: During the COVID-19 pandemic, concern regarding its effect on the management of non-communicable diseases has been raised. However, there are no data on the impact on cardiac implantable electronic devices (CIED) implantation rates. We aimed to determine the impact of SARS-CoV2 on the monthly incidence rates and type of pacemaker (PM) and implantable cardiac defibrillator (ICD) implantations in Catalonia before and after the declaration of the state of alarm in Spain on 14 March 2020. METHODS AND RESULTS: Data on new CIED implantations for 2017-20 were prospectively collected by nine hospitals in Catalonia. A mixed model with random intercepts corrected for time was used to estimate the change in monthly CIED implantations. Compared to the pre-COVID-19 period, an absolute decrease of 56.5% was observed (54.7% in PM and 63.7% in ICD) in CIED implantation rates. Total CIED implantations for 2017-19 and January and February 2020 was 250/month (>195 PM and >55 ICD), decreasing to 207 (161 PM and 46 ICD) in March and 131 (108 PM and 23 ICD) in April 2020. In April 2020, there was a significant fall of 185.25 CIED implantations compared to 2018 [95% confidence interval (CI) 129.6-240.9; P < 0.001] and of 188 CIED compared to 2019 (95% CI 132.3-243.7; P < 0.001). No significant differences in the type of PM or ICD were observed, nor in the indication for primary or secondary prevention. CONCLUSIONS: During the first wave of the COVID-19 pandemic, a substantial decrease in CIED implantations was observed in Catalonia. Our findings call for measures to avoid long-term social impact.

Very high pacing thresholds during long-term follow-up predicted by a combination of implant pacing threshold and impedance in leadless transcatheter pacemakers.

BACKGROUND: Micra transcatheter pacemaker system (TPS) usually achieves low implant pacing threshold (IPT). However, IPT may increase in some patients during follow-up. AIM: To apply implant parameters in predicting long-term occurrence of very high pacing threshold (VHPT) in patients with Micra-TPS. METHODS: A cohort of 110 consecutive patients implanted with a Micra-TPS from 2014 to 2018 was evaluated at discharge and at 1, 12, 24, 36, and 48 months follow-up. VHPT was defined as greater than 2 V/0.24 ms. VHPT predictors were identified. RESULTS: Micra-TPS was implanted successfully in 108 patients (98.2%). During a mean follow-up of 24 ± 16 months, 18 patients (16.7%) died of causes nonpacemaker-related, and 4 (3.8%) developed VHPT. Patients with VHPT had higher IPT and lower implant impedance than patients with non-VHPT: 1 ± 0.31 vs 0.55 ± 0.29 V/0.24 ms (P = .003) and 580 ± 59 vs 837 ± 232 Ω (P = .03), respectively. IPT and impedance had excellent discriminative power to predict VHPT (area under the curve: 0.85 ± 0.07 and 0.91 ± 0.05, respectively). Negative predictive value (NPV) of IPT ≤ 0.5 V/0.24 ms was 100%; positive predictive value (PPV) was 8% throughout follow-up. Implant impedance ≤ 600 Ω had NPV of 99% throughout follow-up, whereas PPV varied: 16%, 21%, 16%, and 28% at 1, 12, 24, and 36 months, respectively. Sequential combination of IPT greater than 0.5 V/0.24 ms and impedance ≤ 600 Ω improved PPV to 25%, 35%, 27%, and 44%, respectively, whereas NPV remained 99% throughout follow-up. CONCLUSION: Despite favorable long-term electrical performance of Micra-TPS, a small percent of patients developed VHPT during follow-up. A sequential combination of IPT and impedance could allow the implanter to identify patients who will develop VHPT during long-term follow-up.

Electrocardiographic optimization techniques in resynchronization therapy.

Cardiac resynchronization therapy (CRT) is a cornerstone of therapy for patients with heart failure, reduced left ventricular (LV) ejection fraction, and a wide QRS complex. However, not all patients respond to CRT: 30% of CRT implanted patients are currently considered clinical non-responders and up to 40% do not achieve LV reverse remodelling. In order to achieve the best CRT response, appropriate patient selection, device implantation, and programming are important factors. Optimization of CRT pacing intervals may improve results, increasing the number of responders, and the magnitude of the response. Echocardiography is considered the reference method for atrioventricular and interventricular (VV) intervals optimization but it is time-consuming, complex and it has a large interobserver and intraobserver variability. Previous studies have linked QRS shortening to clinical response, echocardiographic improvement and favourable prognosis. In this review, we describe the electrocardiographic optimization methods available: 12-lead electrocardiogram; fusion-optimized intervals (FOI); intracardiac electrogram-based algorithms; and electrocardiographic imaging. Fusion-optimized intervals is an electrocardiographic method of optimizing CRT based on QRS duration that combines fusion with intrinsic conduction. The FOI method is feasible and fast, further reduces QRS duration, can be performed during implant, improves acute haemodynamic response, and achieves greater LV remodelling compared with nominal programming of CRT.

Management of anticoagulation in patients undergoing leadless pacemaker implantation.

BACKGROUND: The Micra transcatheter pacing system (Micra TPS) is often implanted in patients with atrial fibrillation and thus with increased thromboembolic risk. It is unknown whether the use of anticoagulants, associated with the use of a large venous introducer, implies an increased risk of bleeding in this group of patients. OBJECTIVE: The purpose of this study was to assess the incidence of bleeding and thromboembolic complications after Micra TPS implantation with and without therapeutic anticoagulation. METHODS: This single-center observational study included 107 consecutive patients receiving the Micra TPS from 2014 to 2018. At procedure completion, a figure-of-eight suture was placed at the femoral puncture site after sheath withdrawal and was maintained for 24 hours. In patients receiving enoxaparin or new oral anticoagulants, treatment was discontinued 12 or 24 hours before the procedure, respectively, and was reinitiated 4-6 hours postprocedure. In those receiving vitamin K antagonists (VKAs), dosing was not discontinued and the procedure was performed if the international normalized ratio was less than 3. RESULTS: Sixty-four patients (60%) did not receive anticoagulants. Of the 43 (40%) who did, 29 (67%) received VKAs, 8 (19%) received new oral anticoagulants, and 6 (14%) received enoxaparin. Two patients presented hemorrhagic or thromboembolic complications during short-term follow-up: 1 woman receiving VKAs presented hemorrhagic pericardial effusion without tamponade and 1 woman not receiving anticoagulants presented thrombosis of the ipsilateral saphenous vein. CONCLUSION: Bleeding and thromboembolic complications after receiving Micra TPSs are infrequent. The use of anticoagulant therapy, regardless of the type, does not increase the complications associated with the procedure.

Failure-free survival of the Riata implantable cardioverter-defibrillator lead after a very long-term follow-up.

AIMS: Riata® implantable cardioverter-defibrillator (ICD) leads from St. Jude Medical are prone to malfunction. This study aimed to describe the rate of this lead's malfunction in a very long-term follow-up. METHODS: This single-centre observational study included 50 patients who received a Riata 7Fr dual-coil lead between 2003 and 2008. Follow-up was conducted both in person and remotely, and analysed at 8-month intervals. We evaluated the rates of cable externalization (CE), electrical failure (EF), and the interaction of these two complications. Structural lead failure was defined as radiographic CE. Oversensing of non-cardiac signal or sudden changes in impedance, sensing, or pacing thresholds constituted EF. RESULTS: During a mean follow-up of 10.2 ±â€¯2.9 years, 16 patients (32%) died. We observed lead malfunction in 13 patients (26%): three (23%) due to CE, six (46%) to EF and four (31%) to both complications. Of the malfunctioning leads, 77% failed after seven years of follow-up. The incidence rate (IR) of overall malfunction per 100 patients per year was 0.9 during the first seven years post-implantation, increased to 7.0 after the 7th year and more than doubled (to 16.7) after 10 years. Beyond seven years post-implantation, IR per 100 patient-years increased in both EF and CE (from 0.6 to 5.6 vs. 0.3 to 4.2, respectively). Presence of CE was associated with a 4-fold increase in the proportion of EF. CONCLUSION: The incidence of Riata ICD lead malfunction, both for EF and CE, increased dramatically after seven years and then more than doubled after 10 years post-implantation.

Shock inadecuado debido al atrapamiento de aire en el bolsillo de un desfibrilador automático implantable subcutáneo / Inappropriate shock due to air entrapment in the pocket of a subcutaneous implantable cardioverter-defibrillator

No disponible

In-vivo compatibility between pacemakers and dental equipment.

In-vitro studies suggest that electromagnetic interference can occur under specific conditions involving proximity between electronic dental equipment and pacemakers. At present, in-vivo investigations to verify the effect of using electronic dental equipment in clinical conditions on patients with pacemakers are scarce. This study aimed to evaluate, in vivo, the effect of three commonly used electronic dental instruments - ultrasonic dental scaler, electric pulp tester, and electronic apex locator - on patients with different pacemaker brands and configurations. Sixty-six consecutive non-pacemaker-dependent patients were enrolled during regular electrophysiology follow-up visits. Electronic dental tools were operated while the pacemaker was interrogated, and the intracardiac electrogram and electrocardiogram were recorded. No interferences were detected in the intracardiac electrogram of any patient during the tests with dental equipment. No abnormalities in pacemaker pacing and sensing function were observed, and no differences were found with respect to the variables, pacemaker brands, pacemaker configuration, or mode of application of the dental equipment. Electromagnetic interferences affecting the surface electrocardiogram, but not the intracardiac electrogram, were found in 25 (37.9%) patients, especially while using the ultrasonic dental scaler; the intrinsic function of the pacemakers was not affected. Under real clinical conditions, none of the electronic dental instruments tested interfered with pacemaker function.

Improvement of Reverse Remodeling Using Electrocardiogram Fusion-Optimized Intervals in Cardiac Resynchronization Therapy: A Randomized Study.

OBJECTIVES: The aim of this study was to compare patient response to cardiac resynchronization therapy (CRT) using fusion-optimized atrioventricular (AV) and interventricular (VV) intervals versus nominal settings. BACKGROUND: The additional benefit obtained by AV- and VV-interval optimization in patients undergoing CRT remains controversial. Previous studies show short-term benefit in hemodynamic parameters; however, midterm randomized comparison between electrocardiogram optimization and nominal parameters is lacking. METHODS: A group of 180 consecutive patients with left bundle branch block treated with CRT were randomized to fusion-optimized intervals (FOI) or nominal settings. In the FOI group, AV and VV intervals were optimized according to the narrowest QRS, using fusion with intrinsic conduction. Clinical response was defined as an increase >10% in the 6-min walk test or an increment of 1 step in New York Heart Association functional class. The left ventricular (LV) remodeling was defined as >15% decrease in left ventricular end-systolic volume (LVESV) at 12-month follow-up. Additionally, patients with LVESV reduction >30% relative to baseline were considered super-responders; by contrast, negative responders had increased LVESV relative to baseline. RESULTS: Participant characteristics included a mean age of 65 ± 10 years, 68% male, 37% with ischemic cardiomyopathy, LV ejection fraction 26 ± 7%, and QRS 180 ± 22 ms. Baseline QRS was shortened significantly more by FOI, compared with nominal settings (-56.55 ± 17.65 ms vs. -37.81 ± 22.07 ms, respectively; p = 0.025). At 12 months, LV reverse remodeling was achieved in a larger proportion of the FOI group (74% vs. 53% [odds ratio: 2.02 (95% confidence interval: 1.08 to 3.76)], respectively; p = 0.026). No significant differences were observed in clinical response (61% vs. 53% [odds ratio: 1.43 (95% confidence interval: 0.79 to 2.59)], respectively; p = 0.24). CONCLUSIONS: Device optimization based on FOI achieves greater LV remodeling, compared with nominal settings. (ECG Optimization of CRT: Evaluation of Mid-Term Response [BEST]; NCT01439529).

Respuesta: La prueba de caminar de 6 minutos o la ergoespirometría en el tratamiento de resincronización cardíaca: ¿amigos o enemigos? / Reply: Test 6-minute walk or ergospirometry in the treatment of cardiac resynchronization: friend or foe?

No disponible

Differentiating hypertrophic cardiomyopathy from athlete's heart: An electrocardiographic and echocardiographic approach.

Differential diagnosis of hypertrophic cardiomyopathy (HCM) vs athlete's heart is challenging in individuals with mild-moderate left-ventricular hypertrophy. This study aimed to assess ECG and echocardiographic parameters proposed for the differential diagnosis of HCM. The study included 75 men in three groups: control (n=30), "gray zone" athletes with interventricular septum (IVS) measuring 13-15mm (n=25) and HCM patients with IVS of 13-18mm (n=20). The most significant differences were found in relative septal thickness (RST), calculated as the ratio of 2 x IVS to left ventricle end-diastolic diameter (LV-EDD) (0.37, 0.51, 0.71, respectively; p<0.01) and in spatial QRS-T angle as visually estimated (9.8, 33.6, 66.2, respectively; p<0.01). The capacity for differential HCM diagnosis of each of the 5 criteria was assessed using the area under the curve (AUC), as follows: LV-EDD<54 (0.60), family history (0.61), T-wave inversion (TWI) (0.67), spatial QRS-T angle>45 (0.75) and RST>0.54 (0.92). Pearson correlation between spatial QRS-T angle>45 and TWI was 0.76 (p 0.01). The combination of spatial QRS-T angle>45 and RST>0.54 for diagnosis of HCM had an AUC of 0.79. The best diagnostic criteria for HCM was RST>0.54. The spatial QRS-T angle>45 did not add sensitivity if TWI was present. No additional improvement in differential diagnosis was obtained by combining parameters.

Plasma tissue inhibitor of matrix metalloproteinase-1 a predictor of long-term mortality in patients treated with cardiac resynchronization therapy.

AIMS: Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are involved in cardiac remodelling. Available information regarding their prognostic utility in heart failure (HF) and cardiac resynchronization therapy (CRT) is controversial. The aim of this study was to analyse MMP-2 and TIMP-1 levels as predictors of long-term mortality in HF patients treated with CRT. METHODS AND RESULTS: We prospectively included 42 consecutive patients with successfully implanted CRT. Matrix metalloproteinase-2 and TIMP-1 assays were performed prior to implant. Patients were evaluated at baseline and at the outpatient clinic at 6-month intervals. Clinical response, left ventricular (LV) remodelling, and mortality were analysed. During a mean follow-up of 60 ± 34 months, long-term mortality from any cause was 36% (15 patients). The cause of death was end stage of HF in 12 patients, sudden death in 2 patients, and 1 unknown. After adjustment using a Cox regression model, the independent predictors of long-term mortality were baseline TIMP-1, hazard ratio (HR) 1.18 (95% confidence interval (95% CI) [1.05-1.33], P = 0.007), baseline glomerular filtration rate (GFR), HR 0.97 (95% CI [0.94-1.00], P = 0.05), and permanent atrial fibrillation (AF), HR 3.14 (95% CI [1.02-9.67], P = 0.04). Area under receiver operating characteristic curve for TIMP-1 was 0.79 (95% CI [0.63-0.94]). Tissue inhibitor of matrix metalloproteinase-1 ≥ 248 ng/mL predicts mortality with 80% sensitivity and 71% specificity. CONCLUSION: Tissue inhibitor of matrix metalloproteinase-1 is a powerful predictor of long-term mortality in HF patients treated with CRT.