Comparison of very high-power short-duration, high-power short-duration, and low-power long-duration radiofrequency ablation for atrial fibrillation: A systematic review and network meta-analysis.

BACKGROUND: The optimal power and duration settings for radiofrequency (RF) atrial fibrillation (AF) ablation to improve efficacy and safety is unclear. We compared low-power long-duration (LPLD), high-power short-duration (HPSD), and very HPSD (vHPSD) RF settings for AF ablation. METHODS: This network meta-analysis (NMA) was structured according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Medline, Scopus and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Observational and randomized studies were included. Eligible studies compared outcomes in AF patients who underwent first-time RF ablation with the following settings: vHPSD (70-90 W, 3-10 s), HPSD (45-60 W, 5-10 s), or LPLD (20-40 W, 20-60 s). RESULTS: Thirty-six studies comprising 10,375 patients were included (33% female). Frequentist NMA showed LPLD tended toward a lower odds of freedom from arrhythmia (FFA) versus HPSD (OR 0.93, 95% CI 0.86-1.00). There was no difference in FFA between vHPSD versus HPSD. Splitwise interval estimates showed a lower odds of FFA in LPLD versus vHPSD on direct (OR 0.78, 95% CI 0.65-0.93) and network estimates (OR 0.85, 95% CI 0.73-0.98). Frequentist NMA showed less total procedural (TP) time with HPSD versus LPLD (generic variance 1.06, 95% CI 0.83 to 1.29) and no difference between HPSD versus vHPSD. CONCLUSION: This NMA shows improved procedural times in HPSD and vHPSD versus LPLD. Although HPSD tended toward improved odds of FFA compared to LPLD, the overall result was not statistically significant. The odds of FFA in LPLD was lower versus vHPSD on direct and network estimates on splitwise interval analysis. Large prospective head-to-head randomized trials are needed to validate HPSD and vHPSD settings.

Evaluating Goldberger's triad as a marker of congestive heart failure: A systematic review and retrospective study.

BACKGROUND: In 1982, Drs. Barold and Goldberger described an ECG triad associated with left ventricular dysfunction (LVD) consisting of high precordial QRS voltage, low limb lead voltage, and poor precordial R wave progression. Studies have since attempted to replicate the originally reported sensitivity (70%), specificity (>99%), and positive predictive value (PPV, 100%) of Goldberger's triad (GT) with variable results. PURPOSE: To assess sensitivity, specificity and PPV of GT as a screening tool for LVD in the current era. METHODS: We performed: (1) A systematic review of the published studies; (2) Searched our hospital ECG database (GE MUSE) for diagnoses of "low limb-voltage" and "left ventricular hypertrophy" from 2017 to 2022; identified ECGs were analyzed for GT criteria and their medical records were screened for LVD. (3) ECG analysis of patients with known idiopathic LVD for the GT. RESULTS: A total of 11,115 patients from 8 studies were included in the systematic review of published studies and showed widely varying sensitivity, specificity and PPV. A total of 4576 ECGs (in GE MUSE) from 372 patients met initial screening criteria of low limb lead voltage and LVH; only 12 patients had ECGs that satisfied GT. Of these 12, only 1 patient had evidence of LVD, yielding a PPV of 8%. Finally, of the 40 patients with known LVD, only 1 met the ECG criteria for GT, resulting in a sensitivity of 2.5%. CONCLUSION: Our literature review does not support the original results of GT. ECGs from our database that met GT (searched by low limb-voltage and left ventricular hypertrophy) over a span of 5 years were rare. When present, the PPV of GT was 8%. In patients with established LVD, the sensitivity was 2.5%. These data do not validate GT as tool to identify LVD in the current era.

Mobile electrocardiographic devices and healthcare utilization in post-atrial fibrillation ablation patients.

BACKGROUND: The use of mobile electrocardiogram (mECG) devices is becoming more prevalent. mECG devices allow instant access to recording arrhythmias and enable automatic rhythm interpretation. Providers can remotely evaluate patients and this may reduce in-person healthcare utilization. We sought to evaluate the utility of mECG devices in reducing healthcare utilization among patients who underwent atrial fibrillation (AF) ablation. METHODS: We identified a population of patients with paroxysmal or persistent AF presenting for their first AF ablation. Patients were divided into two groups: KardiaMobile (AliveCor, Mountain View, CA) mECG users and non-KardiaMobile users. Healthcare utilization was compared between the two groups for one year post-ablation. RESULTS: 184 patients were studied (76 KardiaMobile users, 108 non-KardiaMobile users). There was no difference in the number of office visits (p = 0.59), cardiac-specific emergency department visits (p = 0.26), cardiac-specific hospital admissions (p = 0.13), ablations or cardioversions completed (p = 0.24), telephone encounters (p = 0.05), patient electronic health record messages (p = 0.40), or cardiac imaging (transthoracic or transesophageal echocardiograms) tests ordered (p = 0.36). Exposure to the device was associated with a reduction in ambulatory cardiac monitor use (p = 0.04). There was no difference in sinus rhythm maintenance over 12 months by Kaplan-Meier survival analysis (log rank test p = 0.05) between groups. CONCLUSION: Mobile technology is available for heart rhythm monitoring and can give instant feedback to the user. mECG use is associated with a significant reduction in ambulatory cardiac monitor use in the post-ablation period. There was no difference in other AF-related healthcare utilization.

Low-voltage area substrate modification for atrial fibrillation ablation: a systematic review and meta-analysis of clinical trials.

AIMS: The value of additional ablation beyond pulmonary vein isolation for atrial fibrillation (AF) ablation is unclear, especially for persistent AF. The optimal target for substrate modification to improve outcomes is uncertain. We investigate the utility of low-voltage area (LVA) substrate modification in patients undergoing catheter ablation for AF. METHODS AND RESULTS: This meta-analysis was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Medline, Scopus and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Risk of bias was assessed using the Cochrane risk of bias tool. Only randomized studies were included. AF patients who underwent catheter ablation with voltage-guided substrate modification targeting LVA (LVA group) vs. conventional ablation approaches not targeting LVA (non-LVA group) were compared. Four studies comprising 539 patients were included (36% female). Freedom from arrhythmia (FFA) in patients with persistent AF was greater in the LVA group [risk ratio (RR) 1.30; 95% confidence interval (CI) 1.03-1.64]. There was no difference in FFA in patients with paroxysmal AF between groups (RR 1.30; 95% CI 0.89-1.91). There was no difference in total procedural time (mean difference -17.54 min; 95% CI -64.37 to 29.28 min) or total ablation time (mean difference -36.17 min; 95% CI -93.69 to 21.35 min) in all included patients regardless of AF type between groups. There was no difference in periprocedural complications between groups in all included patients regardless of AF type (RR 0.93; 95% CI 0.22-3.82). CONCLUSION: This meta-analysis demonstrates improved FFA in persistent AF patients who underwent voltage-guided substrate modification targeting LVA.

High-power short-duration versus standard-power standard-duration settings for repeat atrial fibrillation ablation.

INTRODUCTION: High-power short-duration (HPSD) ablation is a novel strategy using contact force-sensing catheters optimized for radiofrequency ablation for atrial fibrillation (AF). No study has directly compared HPSD versus standard-power standard-duration (SPSD) contact force-sensing settings in patients presenting for repeat ablation with AF recurrence after initial ablation. METHODS: We studied consecutive cases of patients with AF undergoing repeat ablation with SPSD or HPSD settings after their initial pulmonary vein isolation (PVI) with temperature controlled non-contact force, SPSD or HPSD settings between 6/23/14 and 3/4/20. Procedural data collected included radiofrequency ablation delivery time (RADT). Clinical data collected include sinus rhythm maintenance post-procedure. RESULTS: A total of 61 patients underwent repeat ablation (36 SPSD, 25 HPSD). A total of 51 patients (83.6%) were found to have pulmonary vein reconnections necessitating repeat isolation, 10 patients (16.4%) had durable PVI and ablation targeted non-PV sources. RADT was shorter when comparing repeat ablation using HPSD compared to SPSD (22 vs 35 min; p = 0.01). There was no difference in sinus rhythm maintenance by Kaplan-Meier survival analysis (log rank test p = 0.87), after 3 or 12-months between groups overall, and when stratified by AF type, left atrial volume index, CHA2DS2-VASc score, or left ventricular ejection fraction. CONCLUSION: We demonstrated that repeat AF ablation with HPSD reduced procedure times with similar sinus rhythm maintenance compared to SPSD in those presenting for repeat ablation.

Comparison of clinical and procedural outcomes between high-power short-duration, standard-power standard-duration, and temperature-controlled noncontact force guided ablation for atrial fibrillation.

INTRODUCTION: High-power short-duration (HPSD) ablation is a novel strategy using contact force-sensing catheters optimized for power-controlled radiofrequency ablation for atrial fibrillation (AF). This study investigates the outcomes of HPSD (50 W delivered for up to 15 s, Lesion Size Index of 5-6) compared to standard-power standard-duration (SPSD) (20-25 W until 400-500 gram seconds, up to 60 s) and temperature-controlled noncontact (TCNC) (20-40 W up to 60 s of ablation) settings. METHODS: We studied consecutive cases of patients with AF undergoing pulmonary vein isolation with TCNC, SPSD, and HPSD between January 7th, 2013 and January 11th, 2019. Procedural data collected include time to isolate the left (LPVT) and right pulmonary veins (RPVT), total ablation time (TAT), and radiofrequency ablation delivery time (RADT). Clinical data collected include sinus rhythm maintenance postprocedure. RESULTS: One hundred and seventy-one patients were studied (44 TCNC, 51 SPSD, 76 HPSD). RADT was shorter when comparing HPSD to SPSD (25 vs. 41 min; p < .01), HPSD to TCNC (25 vs. 76 min; p < .01), and SPSD to TCNC groups (41 vs. 76 min; p < .01). TAT, LPVT, and RPVT were reduced between HPSD versus SPSD, HPSD versus TCNC, and SPSD versus TCNC groups, respectively (p < .01). There was no difference in sinus rhythm maintenance by Kaplan-Meier survival analysis (log rank test p = .12), after 3 or 12 months between groups overall, and when stratified by AF type, left atrial volume, CHA2 DS2 -VASc score, or left ventricular ejection fraction. CONCLUSION: AF ablation with HPSD reduced procedure times with similar sinus rhythm maintenance compared to SPSD and TCNC.

Ventricular tachycardia induced by a backup pacing stimulus in a patient with a dual chamber pacemaker with AutoCapture.

Manufacturers of cardiac implantable electronic devices have incorporated automatic features to allow for remote monitoring, improve device longevity, and additional safety. Algorithms to automatically measure capture threshold and adjust output to preserve battery life are one such feature. Automatic features may occasionally result in unexpected or undesirable clinical outcomes. We report on a patient who developed ventricular tachycardia inadvertently induced by the AutoCapture. feature of an Abbott/St. Jude Medical (SJM) pacemaker.

Expanding a single­lead mobile electrocardiographic device to multiple­lead recordings improves diagnostic accuracy and confidence.

BACKGROUND: Mobile electrocardiographic (mECG) devices that record ECG lead I have been used to detect atrial fibrillation. Other arrhythmias may not be readily diagnosed with one lead. Obtaining multi­lead tracings from an mECG (MLmECG) to simulate a 12­lead ECG may lead to more accurate diagnoses. METHODS: We developed a method to generate multi­lead ECGs using a mECG device by attaching it with alligator clips connected to an insulated copper wire to adhesive electrodes on the patient's limbs and torso according to standard lead configurations. Different rhythm and conduction abnormalities from a sample of inpatients were collected. Arrhythmias were recorded in three ways (single lead, MLmECG, and standard 12­lead) and grouped by category. Recordings were sent to cardiology fellows in the form of a multiple choice survey. Participants were asked for their diagnosis and confidence in their decision. RESULTS: Survey response rate was 100%. Single­lead, MLmECG, and 12­lead yielded 48.2%, 81.6%, and 88.6% of agreement with the correct diagnosis, respectively (single­lead vs. MLmECG or 12­lead; p < 0.01). Overall mean confidence scores were 3.34, 4.35, and 4.53 out of 5, for single­lead, MLmECG, and 12­lead ECG, respectively (single­lead vs. MLmECG or 12­lead; p < 0.01, MLmECG vs. 12­lead; p = 0.09). CONCLUSION: The diagnostic accuracy of MLmECGs were similar to that of a standard 12­lead ECG. Fellows' confidence in their diagnosis were similar between MLmECG or 12­lead ECG, and higher with both modalities compared to a single­lead tracing. The ability to recreate, as fully as possible, a standard 12­lead ECG is a reasonable goal for mobile technology.

Atrial fibrillation post central retinal artery occlusion: Role of implantable loop recorders.

OBJECTIVE: This study evaluated the risk of subclinical atrial fibrillation (AF) in patients with central retinal artery occlusion (CRAO) compared to those with cryptogenic stroke using implantable loop recorders (ILR). METHODS: We conducted a retrospective analysis of 273 consecutive patients who had ILRs inserted at our institution for either cryptogenic stroke (n = 227) or CRAO (n = 46). Our primary endpoint was a time to event analysis for the new diagnosis of AF by ILR. Univariable and multivariable Cox proportional hazard models were used to determine the predictors of time-to-AF. RESULTS: A total of 64 patients were found to have newly diagnosed AF by remote monitoring of the ILR. AF was detected in 57 of 227 (25%) cryptogenic stroke patients by the end of a maximum 5.1 years follow-up and in seven of 46 (15%) CRAO patients by the end of a maximum 3.6 years follow-up (P = .215, log-rank test). The Kaplan-Meier estimates for freedom from AF was 59.4% for CRAO and 66.6% for cryptogenic stroke (P = NS, log-rank test). Baseline variables predicting AF included older patients, higher CHADS2 VASC score, longer PR interval on initial EKG evaluation, and mitral annular calcification on transthoracic echocardiogram. CONCLUSIONS: Patients with CRAO are at risk for subclinical AF, similar to those with cryptogenic stroke. Long-term monitoring to detect AF may lead to changes in pharmacotherapy to reduce the risk for subsequent stroke.

Improved accuracy and confidence with multiple-lead recordings from a single-lead mobile electrocardiographic device.

BACKGROUND: Mobile electrocardiograms (mECGs) utilizing smartphone applications are an emerging technology. Typically, a Lead I rhythm strip is recorded. However, interpretation can be difficult in patients with sinus rhythm and low amplitude P-waves (SR-LAP) or atrial flutter (AFL). We hypothesized that patients could independently obtain multi-lead tracings using a commercial mECG device, and that cardiologists who interpreted the multi-lead tracings would make more accurate diagnoses and have more confidence in their interpretation compared to a single lead only. METHODS: Thirty sets of recordings were obtained from 10 patients with either SR-LAP or AFL that was not apparent on Lead I on a standard ECG. Patients recorded Lead I, Lead II, and Lead V1 tracings using AliveCor's KardiaMobile mECG device. Twenty-nine cardiologists reviewed each patient's Lead I tracing, multi-lead tracings (Leads I, II, V1), and 12-lead ECG. Accuracy was noted and each cardiologist rated their level of confidence in their interpretation. RESULTS: All patients were able to record their own single and multi-lead tracings. Single lead, multi-lead, and the 12-lead ECG yielded 36.4%, 84.3%, and 97.7% agreement with the established diagnosis, respectively (P < .01 for each comparison). Overall mean confidence scores (out of a score of 5) were 2.95, 3.50, and 4.47 for single lead, multi-lead, and the 12-lead ECG, respectively (P < .01 for each comparison). CONCLUSIONS: Patients were able to record their own multi-lead mECG tracings. Compared to a single lead recording, multi-lead mECGs significantly improved cardiologists' diagnostic accuracy and confidence in their interpretation approaching that of a standard 12-lead ECG.

Ablation Versus Antiarrhythmic Drugs as First-Line Therapy for Treatment-Naive Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Evidence on the relative safety and efficacy of atrial fibrillation catheter ablation and antiarrhythmic drugs (AADs) as the first-line therapy for patients with treatment-naive atrial fibrillation (AF) remains disputed. Digital databases were queried to identify relevant randomized controlled trials. The incidence of recurrent AF, major adverse cardiovascular events, and its components (all-cause death, nonfatal stroke, and bleeding) were compared using the DerSimonian and Laird method under the random-effects model to calculate pooled unadjusted risk ratio (RR) with 95% confidence intervals (CIs). A total of 6 randomized controlled trials consisting of 1,120 patients (574 ablation and 549 AADs) were included in the final analysis. Over a median follow-up of 1 year, the risk of any AF recurrence (RR 0.54, 95% CI 0.39 to 0.75) was significantly lower in patients receiving ablation than in patients receiving AADs. However, there was similar risk of major adverse cardiovascular events (RR 2.65, 95% CI 0.61 to 11.46), trial-defined composite end point of adverse events (RR 0.71, 95% CI 0.28 to 1.80), stroke (RR 2.42, 95% CI 0.22 to 26.51), all-cause mortality (RR 1.98, 95% CI 0.28 to 13.90), and procedure/medication failure (RR 2.65, 95% CI 0.61 to 11.46) with both therapies. In conclusion, in patients presenting with treatment-naive AF, ablation as a first-line therapy lowers the risk of AF recurrence with no associated increase in major adverse events, stroke, and mortality compared with AADs.

Adverse outcomes of atrial fibrillation ablation in heart failure patients with and without cardiac amyloidosis: a Nationwide Readmissions Database analysis (2015-2019).

Aims: Atrial fibrillation (AF) in patients with cardiac amyloidosis (CA) has been linked with a worse prognosis. The current study aimed to determine the outcomes of AF catheter ablation in patients with CA. Methods and results: The Nationwide Readmissions Database (2015-2019) was used to identify patients with AF and concomitant heart failure. Among these, patients who underwent catheter ablation were classified into two groups, patients with and without CA. The adjusted odds ratio (aOR) of index admission and 30-day readmission outcomes was calculated using a propensity score matching (PSM) analysis. A total of 148 134 patients with AF undergoing catheter ablation were identified on crude analysis. Using PSM analysis, 616 patients (293 CA-AF, 323 non-CA-AF) were selected based on a balanced distribution of baseline comorbidities. At index admission, AF ablation in patients with CA was associated with significantly higher adjusted odds of net adverse clinical events (NACE) [adjusted odds ratio (aOR) 4.21, 95% CI 1.7-5.20], in-hospital mortality (aOR 9.03, 95% CI 1.12-72.70), and pericardial effusion (aOR 3.30, 95% CI 1.57-6.93) compared with non-CA-AF. There was no significant difference in the odds of stroke, cardiac tamponade, and major bleeding between the two groups. At 30-day readmission, the incidence of NACE and mortality remained high in patients undergoing AF ablation in CA. Conclusion: Compared with non-CA, AF ablation in CA patients is associated with relatively higher in-hospital all-cause mortality and net adverse events both at index admission and up to 30-day follow-up.

Outcomes and Discriminatory Accuracy of the CHA2DS2VASc Score in Atrial Fibrillation and Cancer.

Background: Atrial fibrillation (AF) is highly prevalent among cancer patients. The role of traditional risk stratification scores in the context of different cancer types in these patients remains unknown. Objectives: The purpose of this study was to determine the discriminative accuracy of the CHA2DS2VASc score for ischemic stroke using receiver operating characteristic and area under the curve. Methods: The National Readmission Database (2015-2019) was used to identify all AF patients stratified by the cancer diagnosis, type, and CHA2DS2VASc category (low; moderate; high risk). Outcomes at 30-day readmission were compared between cancer and noncancer groups using hierarchical multivariable logistic regression to calculate adjusted odds ratios (aORs) and 95% CIs. Results: A total of 6,996,088 AF patients were identified at index admission. Of these, 4,242,630 (642,237 cancer, 3,600,393 noncancer) were readmitted at 30 days. Cancer patients (92.1%) had a higher proportion of high CHA2DS2VASc scores compared with their noncancer counterparts (89.8%, P < 0.001). The 30-day readmission rate and incidence of major bleeding in cancer patients were significantly higher compared with their corresponding noncancer group across all CHA2DS2VASc categories. Among the different cancer types, hematological and lung cancer had a high propensity for major bleeding. The odds of ischemic stroke were lower in the cancer group across high (1.9% vs 2.4%; aOR: 0.78; 95% CI: 0.76-0.79; P < 0.0001), moderate (0.8% vs 1.3%; aOR: 0.57; 95% CI: 0.50-0.64; P < 0.0001), and low (0.4% vs 0.9%; aOR: 0.46; 95% CI: 0.34-0.62; P < 0.0001) risk category relative to the noncancer group irrespective of type of cancer. CHA2DS2VASc category had a statistically significant discriminatory accuracy for ischemic stroke in both cancer and noncancer patients. Conclusions: Cancer patients with AF are at a higher risk of readmission and major bleeding. The risk of ischemic stroke during readmission appears to be lower than noncancer patients. These findings may have implications for anticoagulant therapy in cancer patients.

Catheter ablation in patients with atrial fibrillation and heart failure with preserved ejection fraction: A systematic review and meta-analysis.

Background: Catheter ablation for atrial fibrillation (AF) is a proven alternative to pharmacologic rhythm control in patients with heart failure with reduced ejection fraction (HFrEF). Whether outcomes differ in patients with heart failure with preserved ejection fraction (HFpEF) is of interest. Methods: Medline, Scopus, and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Primary efficacy outcomes of interest include atrial arrythmia recurrence and repeat ablation. Harm outcomes of interest include all-cause mortality, all-cause hospitalizations, cardiovascular hospitalizations, stroke/transient ischemic attack, and cardiac tamponade. Results: We included 7 observational studies comprising 2554 patients with HFpEF who underwent catheter ablation for AF. When comparing patients with HFpEF versus without HF, there was no significant difference in atrial arrhythmia recurrence (risk ratio [RR] 1.39; 95% confidence interval [CI] 0.91-2.13), stroke or transient ischemic attack (TIA) (RR 0.47; 95% CI 0.03-6.54), or cardiac tamponade (RR 1.20; 95% CI 0.12-12.20). When comparing patients with HFpEF versus HFrEF, there was no significant difference in atrial arrhythmia recurrence (RR 1.12; 95% CI 0.92-1.37), repeat ablation (RR 1.19; 95% CI 0.74-1.93), all-cause mortality (RR 0.87; 95% CI 0.67-1.13), all-cause hospitalizations (RR 1.10; 95% CI 0.94-1.30), cardiovascular hospitalizations (RR 0.83; 95% CI 0.69-1.01), stroke or TIA (RR 0.81; 95% CI 0.29-2.25), or cardiac tamponade (RR 0.98; 95% CI 0.19-5.16). Conclusions: Non-randomized studies suggest that catheter ablation for AF in patients with HFpEF is associated with similar arrythmia-free survival and safety profile when compared to patients with HFrEF or without heart failure.

Pulmonary vein isolation alone versus pulmonary vein isolation with additional extensive ablation for paroxysmal and persistent atrial fibrillation.

Background: The value of additional ablation beyond pulmonary vein isolation for atrial fibrillation (AF) ablation is unclear, especially for persistent AF. It is uncertain whether substrate modification with additional extensive ablation improves outcomes. We reviewed our experience to determine whether pulmonary vein isolation with additional extensive ablation (PVIEA) improves outcomes compared to pulmonary vein isolation alone (PVIA) for AF ablation. Methods: Consecutive cases of patients with PVIA versus PVIEA were compared between September 9, 2013 and December 12, 2020. Procedural data collected include radiofrequency ablation delivery time (RADT) and arrhythmia inducibility. Clinical data collected include sinus rhythm maintenance post-procedure. Results: A total of 235 patients were studied (67 PVIA and 168 PVIEA). RADT was shorter when comparing ablation with PVIA versus PVIEA (32 vs. 40 min; p = .04). More arrhythmias were inducible with PVIEA (p < .01). There was no difference in sinus rhythm maintenance by Kaplan-Meier survival analysis (log-rank test p = .75), after 3 or 12 months between groups overall, and when stratified by AF type (paroxysmal and persistent), left atrial volume, CHA2DS2-VASc score, left ventricular ejection fraction, or catheter ablation setting (high-power short-duration, standard-power standard-duration, temperature-controlled non-contact-force). Conclusion: AF ablation with PVIA or PVIEA produces similar sinus rhythm maintenance overall and when stratified by catheter setting and AF type. PVIA reduced procedure times and less arrhythmias were inducible post-ablation.

Algorithm for cavo-tricuspid isthmus flutter on surface ECGs: the ACTIONS study.

OBJECTIVE: Cavo-tricuspid isthmus atrial flutter (CTI-AFL) is an important arrhythmia to recognise because there is a highly effective and relatively low-risk ablation strategy. However, clinical experience has demonstrated that providers often have difficulty distinguishing AFL from atrial fibrillation. METHODS: We developed a novel ECG-based three-step algorithm to identify CTI-AFL based on established CTI flutter characteristics and verified on consecutive ablation cases of typical flutter, atypical flutter and atrial fibrillation. The algorithm assesses V1/inferior lead F-wave concordance, consistency of P-wave morphology and the presence of isoelectric intervals in the inferior leads. In this observation study, the algorithm was validated on a cohort of 50 second-year medical students. Students were paired in a control and experimental group, and each pair received 10 randomly selected ECGs (from a pool of 50 intracardiac electrogram-proven CTI-AFL and 50 AF or atypical AFL cases). The experimental group received a cover sheet with the CTI algorithm, and the control group received no additional guidance. RESULTS: There was a statistically significant difference in the mean number of correctly identified ECGs among the students in the experimental and control groups (8.12 vs 5.68, p<0.001). Students who used the algorithm correctly identified 2.44 more ECGs as being CTI-AFL or not CTI-AFL. Using the electrophysiology study as the gold standard, the algorithm had an accuracy of 81%, sensitivity of 81%, specificity of 82%, positive predictive value of 78% and negative predictive value of 84% in identifying CTI-AFL. CONCLUSION: We developed a three-step ECG algorithm that provides a simple, sensitive, specific and accurate tool to identify CTI-AFL.

Usefulness of Mobile Electrocardiographic Devices to Reduce Urgent Healthcare Visits.

Mobile electrocardiogram (mECG) devices are being used increasingly, supplying recordings to providers and providing automatic rhythm interpretation. Given the intermittent nature of certain cardiac arrhythmias, mECGs allow instant access to a recording device. In the current COVID-19 pandemic, efforts to limit in-person patient interactions and avoid overwhelming emergency and inpatient services would add value. Our goal was to evaluate whether a mECG device would reduce healthcare utilization overall, particularly those of urgent nature. We identified a cohort of KardiaMobile (AliveCor, USA) mECG users and compared their healthcare utilization 1 year prior to obtaining the device and 1 year after. One hundred and twenty-eight patients were studied (mean age 64, 47% female). Mean duration of follow-up pre-intervention was 9.8 months. One hundred and twenty-three of 128 individuals completed post-intervention follow-up. Patients were less likely to have cardiac monitors ordered (30 vs 6; p <0.01), outpatient office visits (525 vs 382; p <0.01), cardiac-specific ED visits (51 vs 30; p <0.01), arrhythmia related ED visits (45 vs 20; p <0.01), and unplanned arrhythmia admissions (34 vs 11; p <0.01) in the year after obtaining a KardiaMobile device compared to the year prior to obtaining the device. Mobile technology is available for heart rhythm monitoring and can give feedback to the user. This study showed a reduction of in-person, healthcare utilization with mECG device use. In conclusion, this strategy would be expected to decrease the risk of exposure to patients and providers and would avoid overwhelming emergency and inpatient services.

Initial Experience in Monitoring QT Intervals Using a Six-lead Contactless Mobile Electrocardiogram in an Inpatient Setting.

Mobile electrocardiograms (ECGs) (mECGs) using smartphone applications are an emerging technology. In the coronavirus disease 2019 (COVID-19) era, minimizing patient contact has gained increasing importance. Additionally, increased QT/corrected QT (QTc) monitoring has concurrently been required. The KardiaMobile 6L ECG device, cleared by the United States Food and Drug Administration (FDA) for recording ECGs, along with the KardiaStation tablet application is a platform (AliveCor, Mountain View, CA, USA) that addresses these two issues. A team of residents, fellows, hospitalists, and cardiologists identified inpatients in need of QT/QTc interval monitoring to pilot the adoption of a system composed of a KardiaMobile 6L ECG device with the accompanying KardiaStation tablet application. Concurrent standard ECGs provided validation. Adoption and performance issues were recorded. Four patients agreed to participate in QT/QTc interval monitoring, three of whom were positive for severe acute respiratory syndrome coronavirus 2 viral infection. After basic instructions were given to the patients and their clinical nurses, all patients recorded mECGs successfully. Patients were able to record their own mECG tracings at least once without any assistance. The 12-lead ECGs and mECGs each showed the correct rhythm, and the measured QTc intervals on each modality were consistently acceptable (< 500 ms). Contactless ECGs were successfully uploaded to KardiaStation for QT/QTc interval measurement and archiving. In this study, we showed that an FDA-cleared product, KardiaMobile 6L, has the ability to provide high-quality contactless ECGs for reliable QT/QTc interval measurements. Hospitalized patients were able to perform recordings when requested after receiving simple instructions at the time of first use. This technology has applications during the COVID-19 pandemic and beyond.

The diagnostic yield of implantable loop recorders stratified by indication: "real-world" use in a large academic hospital.

PURPOSE: To report on the clinical utility of implantable loop recorders (ILRs) in a large academic hospital setting over a 4-year period. METHODS: Retrospective study (2013-2016) of patients receiving ILRs for any indication including syncope, cryptogenic stroke (CrS), atrial fibrillation (AF) burden, palpitations, ventricular arrhythmias (VA), and other. Remote checks, symptomatic transmissions, and in-person checks were reviewed. Time to diagnosis was documented. RESULTS: A total of 263 patients (54% male, mean age 63 ± 15 years, mean follow-up 601 (range 9-1714) days) received ILRs for 324 indications; multiple indications were noted in 53/263 (20.2%) patients. ILR indications were 126 (39%) syncope, 81 (25%) CrS, 46 (14%) AF, 37 (11%) palpitations, 10 (3%) VA, and 24 (7%) other. Diagnostic yield for each indication was compared to the overall yield for all other indications. Three indications showed a significantly higher yield: AF (65% vs. 22%, p < 0.002), palpitations (60% vs. 24%, p < 0.001), and VA (70% vs. 28%, p < 0.004). For all other indications, there were no significant differences. Syncope had nearly half the diagnostic yield of previously published trials (28% vs. 43-56%). We observed a fourfold increase in ILR implant rate over the study duration. CONCLUSIONS: In a "real-world" academic hospital setting, the diagnostic rate of ILRs was highest for AF, palpitations, and VA; however, these high yield indications comprised only 29% of all indications. The diagnostic yield for the commonest indication (syncope) was approximately half that reported in the previously published trials. With increasing implantation rates, additional studies are required to refine guideline-based indications for ILR implantation to improve diagnostic yield.