[VT ablation - a technically complex procedure]. / Ablationsbehandling hos patienter med strukturell hjärtsjukdom.

Ventricular tachycardia (VT) in patients with structural heart disease is potentially life threatening, and most patients have an indication for an implantable cardioverter-defibrillator (ICD). Catheter ablation is an effective therapeutic strategy to reduce the risk of VT recurrence and subsequent ICD therapies. However, VT ablation is a technically complex procedure with significant risks and should be performed in experienced centers with appropriate resources. While several reports on outcome and procedural risks have been published, there is currently no data from Sweden. In addition to this literature review, we have analyzed VT ablation outcome data from our center. In 2021 and 2022, 68 VT ablations were performed in 60 patients with structural heart disease. After a median follow-up of 20 months, 18 percent had recurrent VT and there were 2 major adverse events (stroke and complete atrioventricular block). Seven patients died from non-arrhythmia related causes during follow-up. A large proportion (68 percent) were subacute procedures which are associated with a higher periprocedural risk. Referral for VT ablation earlier in the course of disease progression may likely further improve outcomes.

Reduced dementia risk in patients with optimized anticoagulation therapy undergoing atrial fibrillation ablation.

BACKGROUND: Atrial fibrillation (AF) is associated with the development of dementia, and observational studies have shown that oral anticoagulation and catheter ablation reduce dementia risk. However, such studies did not consistently report on periprocedural anticoagulation and long-term oral anticoagulation coverage, for which reason the separate effect of AF ablation on dementia risk could not be established. OBJECTIVE: We evaluated the protective effect of AF ablation in a large cohort of patients who received optimized anticoagulation and compared them with patients who were managed medically. METHODS: We retrospectively included 5912 consecutive patients who underwent first-time catheter ablation for AF between 2008 and 2018 and compared them with 52,681 control individuals from the Swedish Patient Register. Propensity score matching produced 2 cohorts of equal size (n = 3940) with similar baseline characteristics. Dementia diagnosis was identified by International Classification of Diseases codes from the patient register. RESULTS: Most propensity score-matched patients were taking an oral anticoagulant at the start (94.5%) and end (75.0%) of the study. Mean follow-up was 4.9 ± 2.8 years. Catheter ablation was associated with lower risk for the dementia diagnosis compared with the control group (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.22-0.86; P = .017). The result was similar when including patients with a stroke diagnosis before inclusion (HR, 0.50; 95% CI, 0.28-0.89; P = .019) and after adjustment for the competing risk of death (HR, 0.41; 95% CI, 0.20-0.86; P = .018). CONCLUSION: Catheter ablation of AF in patients with optimized oral anticoagulation therapy was associated with a reduction in dementia diagnosis, even after adjustment for potential confounders and for competing risk of death.

Predictors of low-voltage zones in patients with persistent atrial fibrillation eligible for catheter ablation: An observational study.

INTRODUCTION: The presence of low-voltage zones (LVZs) in the left atrium (LA) is associated with the recurrence of atrial fibrillation (AF) following pulmonary vein isolation (PVI). However, there is variability and conflict in the data regarding predictors of LVZs as reported in previous studies. The objective of this study was to identify predictors for the presence of LVZs in a cohort of patients with persistent AF. METHODS: The study prospectively enrolled 439 patients with persistent AF who were scheduled for ablation. Voltage map of the LA was collected using a multipolar catheter. An LVZ was defined as an area of ≥3 cm2 exhibiting a peak-to-peak bipolar voltage of <0.5 mV. RESULTS: The mean age of the cohort was 65.3 ± 8.6 years and 26.4% were female. Additionally, 25.7% had significant LVZs, most frequently located in the anterior wall of the LA. Multivariable analysis identified the following independent predictors for LVZ: advanced age (OR [odds ratio] = 1.08, 95% CI [confidence interval] = 1.03-1.13, p = .002); female sex (OR = 4.83, 95% CI = 2.66-8.76, p < .001); coronary artery disease (CAD) (OR = 3.20, 95% CI = 1.32-7.77, p = .01) and enlarged LA diameter (OR = 1.10, 95% CI = 1.04-1.17, p = .001). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the final model was 0.829. CONCLUSION: Approximately 25% of the patients with persistent AF had LVZs. Advanced age, female sex, CAD, and a larger LA were independent predictors for LVZs with the model demonstrating a very good AUC for the ROC curve. These findings hold the potential to be used to tailor the ablation procedure for the individual patient.

Risk assessment in patients with symptomatic and asymptomatic pre-excitation.

AIMS: Controversy remains as to whether the exercise stress test (EST) is sufficient for risk evaluation in patients with pre-excitation. This study aims to clarify the usefulness of EST in risk stratification in both asymptomatic and symptomatic patients presenting with pre-excitation. METHODS AND RESULTS: This prospective study includes consecutive asymptomatic and symptomatic patients with pre-excitation referred for risk assessment. All participants performed an incremental EST (bicycle) prior to an electrophysiology study (EPS). Primary data from the EST included loss of pre-excitation during exercise, and primary data from the EPS included the measurement of accessory pathway effective refractory period (APERP), shortest pre-excited RR interval (SPERRI), and inducible arrhythmia with the use of a beta-adrenergic receptor agonist if deemed necessary. One hundred and sixty-four patients (59 asymptomatic, 105 symptomatic) completed an EST and EPS. Forty-five patients (27%) demonstrated low-risk findings on EST, of which 19 were asymptomatic and 26 were symptomatic. Six patients with low-risk EST findings had SPERRI/APERP ≤ 250 ms at EPS, and two of them were asymptomatic. The sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of low-risk EST for excluding patients with SPERRI/APERP ≤ 250 ms were 40, 91, 87, 51, and 60%, respectively. The number of patients with inducible arrhythmia at EPS was similar in the asymptomatic (36, 69%) and symptomatic (73, 61%) groups. CONCLUSION: Sudden loss of pre-excitation during EST has a low NPV in excluding high-risk APs. The EPS with the use of isoproterenol should be considered to accurately assess the risk of patients with pre-excitation regardless of symptoms (ClinicalTrials.gov Identifier: NCT03301935).

Association between catheter ablation of atrial fibrillation and mortality or stroke.

OBJECTIVE: Catheter ablation of atrial fibrillation effectively reduces symptomatic burden. However, its long-term effect on mortality and stroke is unclear. We investigated if patients with atrial fibrillation who undergo catheter ablation have lower risk for all-cause mortality or stroke than patients who are managed medically. METHODS: We retrospectively included 5628 consecutive patients who underwent first-time catheter ablation for atrial fibrillation between 2008 and 2018 at three major Swedish electrophysiology units. Control individuals with an atrial fibrillation diagnosis but without previous stroke were selected from the Swedish National Patient Register, resulting in a control group of 48 676 patients. Propensity score matching was performed to produce two cohorts of equal size (n=3955) with similar baseline characteristics. The primary endpoint was a composite of all-cause mortality or stroke. RESULTS: Patients who underwent catheter ablation were healthier (mean CHA2DS2-VASc score 1.4±1.4 vs 1.6±1.5, p<0.001), had a higher median income (288 vs 212 1000 Swedish krona [KSEK]/year, p<0.001) and had more frequently received university education (45.1% vs 28.9%, p<0.001). Mean follow-up was 4.5±2.8 years. After propensity score matching, catheter ablation was associated with lower risk for the combined primary endpoint (HR 0.58, 95% CI 0.48 to 0.69). The result was mainly driven by a decrease in all-cause mortality (HR 0.51, 95% CI 0.41 to 0.63), with stroke reduction showing a trend in favour of catheter ablation (HR 0.75, 95% CI 0.53 to 1.07). CONCLUSIONS: Catheter ablation of atrial fibrillation was associated with a reduction in the primary endpoint of all-cause mortality or stroke. This result was driven by a marked reduction in all-cause mortality.

Elite female endurance athletes are at increased risk of atrial fibrillation compared to the general population: a matched cohort study.

OBJECTIVE: Previous studies have found that endurance sport activity is associated with an increased risk of atrial fibrillation (AF) in men. However, it remains unclear whether endurance sports also influence the risk of AF in women. We aimed to examine whether participation in endurance sports may affect the risk of AF in female athletes. METHODS: We conducted a retrospective matched cohort study of top Swedish female endurance athletes (n=228) and reference individuals (n=1368) from the general population using the Swedish Total Population Register individually matched with a 6:1 ratio of female athletes. The athlete cohort was created by combining all Swedish women who ran the Stockholm Marathon faster than 3 hours 15 min in any of the races between 1979 and 1991, all women competing in the Swedish athletic national championships in the 10 000 metre race, and the top-ranked Swedish cyclists during the same period. We used the National Patient Register to determine whether the participants were diagnosed with AF. RESULTS: Mean age at the start of follow-up was 32 (SD±8.5) years. During follow-up (mean 28.8 years; SD±4.4), 33 cases of AF were diagnosed, including 10 (4.4%) among athletes and 23 (1.7%) among references. The HR for female athletes compared with the reference population was 2.56 (95% CI 1.22 to 5.37) in the univariable model and 3.67 (95% CI 1.71 to 7.87) after adjustment for hypertension. CONCLUSION: Elite female endurance athletes are at increased risk of AF than the general population.

Validation of diagnostic accuracy of a handheld, smartphone-based rhythm recording device.

AIM: Evaluation of the diagnostic accuracy of a rhythm recording device, for detection of atrial tachyarrhythmia (ATA) and atrial fibrillation (AF) compared to 12-lead-electrocardiogram (12-L-ECG). RESEARCH DESIGN AND METHODS: Two hundred 12-L-ECGs (reference standard) and Coala Heart Monitor (CHM) recordings (index test) were collected from 189 patients. Two electrophysiologists independently performed manual analysis of all 12-L-ECGs and CHM recordings in random order. The CHM recordings were also analyzed by an automatic algorithm and compared to the results of the reference standard. RESULTS: Manual analysis of CHM for ATA showed a sensitivity of 98.9% (95% confidence interval (CI): 94.0-100) and a specificity of 100% (CI: 96.6-100). Manual analysis for AF had a sensitivity of 100% (CI: 95.3-100) and a specificity of 97.5% (CI: 93.0-99.5). Automatic analysis for ATA showed a sensitivity of 93.5% (CI: 86.3-97.6) and a specificity of 92.6% (CI: 85.9-96.7). Automatic analysis for AF showed a sensitivity of 97.4% (CI: 91.0-99.7) and a specificity of 86.1% (CI: 78.6-91.7). CONCLUSION: CHM has a very high accuracy for ATA and AF in manual analysis and a high accuracy for ATA and AF in automatic analysis, making the device suitable for screening.

Electrical cardioversion for early recurrences post pulmonary vein isolation.

BACKGROUND: To study the association between timing and success of electrical cardioversion (ECV) for the treatment of early recurrences (ERs) of atrial fibrillation post pulmonary vein isolation (PVI) on long-term rhythm outcome. METHODS: Data of 133 patients ablated for paroxysmal or persistent atrial fibrillation receiving ECV for ERs, i.e., atrial tachyarrhythmia recurrences within 90 days post ablation were analyzed. During 1-year follow-up, patients were screened for late recurrences (LRs), i.e., recurrences after the blanking period. RESULTS: In 114 patients (85.7%), ECV was successful compared to 19 patients (14.3%) with failed ECV. A higher body mass index (odds ratio (OR) 1.19 (95% CI 1.02-1.39), p = 0.029), a lower left ventricular ejection fraction (OR 1.07 (95% CI 0.99-1.15), p = 0.079), and performance of ECV > 7 days from ER onset (OR 2.99 (95% CI 1.01-8.87), p = 0.048) remained independently associated with ECV failure. During 1-year follow-up, the rate of LR was significantly higher among patients with failed ECV as compared to patients with successful ECV (hazard ratio (HR) 3.00 (95% CI, 1.79-5.03), p < 0.001). Patients with ECV performed > 7 days from ER onset had a significantly higher risk of developing LR as compared to patients with ECV performed within ≤ 7 days from ER onset (HR 1.73 (95% CI 1.15-2.62), p = 0.009). Performance of ECV > 7 days from ER onset (HR 1.76 (95% CI 1.16-2.67), p = 0.008) and failed ECV (HR 3.32 (95% CI 1.96-5.64), p < 0.001) remained independently associated with LR. CONCLUSIONS: A failed ECV and performance of ECV > 7 days from ER onset were independently associated with LR.

Feasibility of a novel algorithm for automated reconstruction of the left atrial anatomy based on intracardiac echocardiography.

BACKGROUND: Intracardiac echocardiography (ICE) is frequently used to guide electrophysiology procedures. The novel automated algorithm Cartosoundfam is a model-based algorithm which reconstructs a 3D anatomy of the left atrium (LA) based on a set of 2D intracardiac echocardiography (ICE) frames, without the need to manually annotate ultrasound (US) contours. OBJECTIVE: The aim of this study was to determine the feasibility of the Cartosoundfam module in routine clinical setting. METHODS: We included 16 patients undergoing LA mapping/catheter ablation. Two-dimensional US frames were acquired from the right atrium (RA) and the right ventricular outflow tract. The Cartosoundfam map was validated in two steps: (1) identification of anatomical structures (pulmonary veins [PV] and LA body and appendage) by alignment of the ablation catheter to the automated map; and (2) analysis of the automated lesion tags (Visitag) location in relation to the PV antrum of the Cartosoundfam map in nine patients with paroxysmal atrial fibrillation (AF) undergoing first time pulmonary vein isolation (PVI). RESULTS: Mean 2D US frames per patient were 29 ± 6 and acquisition time was 16 ± 4 min. All anatomical structures were correctly identified in all patients (step 1). In the step 2 validation, the median distance to the map was 2.0 (IQR: 2.4) mm and the majority of the Visitags were classified as satisfactory (69%) but all PV segments had some Visitags classified as unsatisfactory. CONCLUSION: The automated ICE-based algorithm correctly identified the LA anatomical structures in all patients with a 69% anatomical accuracy of the Visitags alignments to the PV antrum segments.

Women with atrial fibrillation undergoing pulmonary vein isolation are more symptomatic but improve more in health-related quality of life and symptom burden than men.

Gender differences in symptoms and perceived health-related quality of life (HRQOL) in patients with atrial fibrillation (AF) referred to pulmonary vein isolation (PVI) have been reported previously. Women experience a lower HRQOL, faster heart rate, and more symptoms such as palpitation and dyspnea than men. Furthermore, they experience worse physical functioning independently of other heart diseases or age. This study evaluates referral patterns and symptoms, morbidity, functional impairment, and HRQOL from a gender perspective in patients with AF before and 6 months after PVI. The study includes 242 patients (121 men), mean age 62 ± 9 years, referred for PVI. Symptoms were assessed with the Symptom Checklist: Frequency and Severity (SCL), HRQOL with Short Form 36 (SF-36), and the functional impairment with Sickness Impact Profile (SIP). The patients' own experiences of the referral process and history of their disease were evaluated with a supplementary questionnaire. The results showed that women improved more than men in HRQOL, SIP, and SCL 6 months post PVI. There were no sex differences in proportion of paroxysmal and persistent AF or ablation outcome. At baseline, women scored higher than men in both scales of the SCL (p < 0.001), scored lower in all components in SF-36, and scored higher in five categories of the SIP. Women were not more reluctant to accept referral for ablation when offered. The conclusion is that women with AF undergoing PVI are more symptomatic but also improve more in HRQOL and in symptom burden than men.

Transseptal Access Through an Atrial Septal Defect Closure Device Resulting in Open Heart Surgery.

A pulmonary vein isolation procedure in a patient with an atrial septal defect (ASD) closure device was complicated by entrapment of a mapping catheter in the device. The procedure was converted to open heart surgery, the device with the trapped catheter was explanted, the ASD was covered with a bovine patch, and a cryomaze procedure was performed. (Level of Difficulty: Intermediate.).

Accessory pathway properties are similar in symptomatic and asymptomatic preexcitation.

PURPOSE: Patients with WPW syndrome have an increased mortality rate compared to the general population. Although asymptomatic preexcitation has previously been considered benign, recent studies have found that also asymptomatic patients have clinical and electrophysiological factors associated with increased risk of sudden cardiac death. This study compares the baseline electrophysiological characteristics of accessory pathways in symptomatic and asymptomatic patients with preexcitation. We hypothesized that a significant proportion of asymptomatic patients has inducible orthodromic tachycardia during programmed electrical stimulation. METHODS: This retrospective study includes 1853 patients with preexcitation who underwent invasive electrophysiological testing in two Swedish University Hospitals between 1991 and 2018. The mean age was 36 ± 17 years with a range of 3-89 years. Thirty-nine percent was women. A total of 269 patients (15%) were children younger than 18 years. Electrophysiological data included effective refractory period of the accessory pathway (APERP, in 1069 patients), tachycardia cycle length, inducibility and type of tachycardia, and AP localization. RESULTS: A total of 1703 (93%) patients reported symptoms suggesting tachyarrhythmias before the study and 128 (7%) were asymptomatic. The proportion of potentially dangerous pathways with short APERP (≤ 250 ms) were similar in symptomatic and asymptomatic patients (187/949, 20% vs. 25/108, 23%) (P = 0.40) as was the mean APERP (303 ± 68 ms vs. 307 ± 75) (P = 0.61). The proportion of patients who had inducible arrhythmia was larger in the symptomatic group (64% vs. 31%) (P < 0.001). CONCLUSION: The results of this study strengthen the present guideline recommendation (IIA) to consider invasive risk assessment in patients with asymptomatic preexcitation.

Randomized Ablation-Based Rhythm-Control Versus Rate-Control Trial in Patients With Heart Failure and Atrial Fibrillation: Results from the RAFT-AF trial.

BACKGROUND: Atrial fibrillation (AF) and heart failure (HF) frequently coexist and can be challenging to treat. Pharmacologically based rhythm control of AF has not proven to be superior to rate control. Ablation-based rhythm control was compared with rate control to evaluate if clinical outcomes in patients with HF and AF could be improved. METHODS: This was a multicenter, open-label trial with blinded outcome evaluation using a central adjudication committee. Patients with high-burden paroxysmal (>4 episodes in 6 months) or persistent (duration <3 years) AF, New York Heart Association class II to III HF, and elevated NT-proBNP (N-terminal pro brain natriuretic peptide) were randomly assigned to ablation-based rhythm control or rate control. The primary outcome was a composite of all-cause mortality and all HF events, with a minimum follow-up of 2 years. Secondary outcomes included left ventricular ejection fraction, 6-minute walk test, and NT-proBNP. Quality of life was measured using the Minnesota Living With Heart Failure Questionnaire and the AF Effect on Quality of Life. The primary analysis was time-to-event using Cox proportional hazards modeling. The trial was stopped early because of a determination of apparent futility by the Data Safety Monitoring Committee. RESULTS: From December 1, 2011, to January 20, 2018, 411 patients were randomly assigned to ablation-based rhythm control (n=214) or rate control (n=197). The primary outcome occurred in 50 (23.4%) patients in the ablation-based rhythm-control group and 64 (32.5%) patients in the rate-control group (hazard ratio, 0.71 [95% CI, 0.49-1.03]; P=0.066). Left ventricular ejection fraction increased in the ablation-based group (10.1±1.2% versus 3.8±1.2%, P=0.017), 6-minute walk distance improved (44.9±9.1 m versus 27.5±9.7 m, P=0.025), and NT-proBNP demonstrated a decrease (mean change -77.1% versus -39.2%, P<0.0001). Minnesota Living With Heart Failure Questionnaire demonstrated greater improvement in the ablation-based rhythm-control group (least-squares mean difference of -5.4 [95% CI, -10.5 to -0.3]; P=0.0036), as did the AF Effect on Quality of Life score (least-squares mean difference of 6.2 [95% CI, 1.7-10.7]; P=0.0005). Serious adverse events were observed in 50% of patients in both treatment groups. CONCLUSIONS: In patients with high-burden AF and HF, there was no statistical difference in all-cause mortality or HF events with ablation-based rhythm control versus rate control; however, there was a nonsignificant trend for improved outcomes with ablation-based rhythm control over rate control. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01420393.

Color Variations in Left Atrial Appendage Occluders.

The authors stopped a case of left atrial appendage occlusion because of miscolored brownish devices. The investigation demonstrated that devices may show a range of colors from a typical blue to a brownish hue, depending on oxide layer thickness, and this does not appear to have any impact on the performance of the device. (Level of Difficulty: Intermediate.).

Low incidence of major complications after the first six hours post atrial fibrillation ablation: Is same-day discharge safe and feasible in most patients?

AIMS: This study evaluates the incidence of procedural complications related to catheter ablation of atrial fibrillation (AF) to assess the potential feasibility and safety of same-day discharge in a large cohort. METHODS: We performed an analysis of prospectively collected data of complications of all patients staying overnight after undergoing AF ablation between 2001 and 2020 at a tertiary center. Using medical records, we analyzed complications occurring intraprocedurally until 6 h postablation and between 6 h postablation and discharge the day after the ablation procedure. RESULTS: In 5414 AF ablations, we identified a total of 108 (2.0%) major complications occurring intraprocedural or before discharge. Most major complications occurred intraprocedurally or within 6 h after the procedure (n = 96, 1.8%). Twelve (0.2%) major complications occurred between 6 h Postablation and discharge. The most common of these major complications were congestive heart failure (n = 6) and transient ischemic attack (TIA, n = 4). During this time span, 61 (1.1%) minor complications occurred. Factors independently associated with major complications intraprocedurally and until discharge were body mass index (BMI) ≥ 30 kg/m2 (p = .009), significant valvular disease (p = .001), cardiomyopathy (p < .001), prior stroke or TIA (p = .014), first-time procedure versus repeat procedure (p = .013), cryoablation versus radiofrequency (p < .001), and procedure duration (p < .001). CONCLUSION: After AF ablation, very few complications occurred between 6 h postprocedure and discharge the next day. Therefore, same-day discharge is a safe option for a majority of patients.

Instant electrocardiogram feedback with a new digital technique reduces symptoms caused by palpitations and increases health-related quality of life (the RedHeart study).

AIMS: Palpitations, particularly common in women, are generally considered benign symptoms rarely caused by clinically important arrhythmias. Nevertheless, palpitations may cause anxiety, depression, and decreased health-related quality of life (HRQOL). This study investigates to what degree palpitations cause symptoms such as anxiety and depression and affect HRQOL in women and whether direct feedback of underlying heart rhythm during palpitations decrease anxiety and depression and increase HRQOL in women. METHODS AND RESULTS: The study included 821 women, age 21-88 years (mean 57 ± 11 years), with symptomatic palpitations recruited using social media. For 60 days, the participants used a handheld electrocardiogram (ECG)-recording device (Coala Heart Monitor) connected to their smartphones. ECG was recorded twice a day and when symptoms were present and was automatically algorithm-interpreted with immediate response to the user. Non-benign arrhythmias were also analysed manually. Questionnaires addressing anxiety and depression-Hospital Anxiety and Depression Scale (HADS), Generalized Anxiety Disorder (GAD-7), HRQOL (RAND-36), and Symptoms Checklist: Frequency and Severity (SCL)-were analysed before and after the data were collected. A total of 101 804 ECG recordings were automatically analysed. In 94%, sinus rhythm or premature atrial/ventricular contraction were recorded; in 6%, atrial fibrillation or supraventricular tachycardia were recorded. Apart from premature ventricular contractions, no ventricular arrhythmias were documented. Anxiety and depression (HADS and GAD-7) decreased (P < 0.001) as did frequency and severity of symptoms, and HRQOL increased in all domains (P < 0.001) at the 2-month follow-up. CONCLUSION: Instant analysis of the ECG with direct response during palpitations decreases symptoms, anxiety, and depression and increases HRQOL in women.

Improving Efficiency of Clinical Studies Using a Total Digital Approach: Prospective Observational Study.

BACKGROUND: In general, most clinical studies have long recruitment periods. Signing the informed consent is particularly time-consuming when the participant must meet physically with the researchers. Therefore, introducing fully web-based techniques with the use of eAuthentication (BankID) and new digital electrocardiogram (ECG) monitoring could speed up inclusion time, increase adherence, and also reach out to more remote regions. OBJECTIVE: The objectives of this study were to explore whether inclusion of a large number of participants could be realized quickly by using a total digital approach both for information and signing of informed consent, along with ECG monitoring and instant feedback on a mobile device. We also explored whether this approach can increase adherence in registration of ECG recordings and answering questionnaires, and if it would result in a more geographically uniform distribution of participants covering a wide age span. METHODS: Women with palpitations were intensively studied over 2 months by means of a handheld ECG monitoring device (Coala Heart Monitor). The device connects to a smartphone or tablet, which allows the participants to obtain the results immediately. Recruitment, study information, and signing the informed consent form with the help of BankID were performed in a completely digital manner. RESULTS: Between March and May 2018, 2424 women indicated their interest in participating in the study. On June 19, 2018, presumptive participants were invited to log in and register. After 25 days, 1082 women were included in the study; among these, 1020 women fulfilled the inclusion criteria, 913 of whom completed all phases of the study: recording ECG using the handheld device, completion of the prestudy questionnaires, and completion of the poststudy questionnaires 2 months after the ECG recordings. The dropout rate was 9%. In total, 101,804 ECG recordings were made. The mean age was 56 (SD 11) years (range 21-88 years) and 35 participants were 75 years or older. The participants were evenly distributed between living in the countryside and in cities. CONCLUSIONS: Total digital inclusion recruitment of 1082 participants was achieved in only 25 days, and resulted in a good geographical distribution, excellent adherence, and ability to reach a vast age span, including elderly women. Studies using a total digital design would be particularly appealing during a pandemic since physical contact should be avoided as much as possible. TRIAL REGISTRATION: ISRCTN Registry ISRCTN22495299; http://www.isrctn.com/ISRCTN22495299.