A Modular Communicative Leadless Pacing-Defibrillator System.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) is associated with fewer lead-related complications than a transvenous ICD; however, the subcutaneous ICD cannot provide bradycardia and antitachycardia pacing. Whether a modular pacing-defibrillator system comprising a leadless pacemaker in wireless communication with a subcutaneous ICD to provide antitachycardia and bradycardia pacing is safe remains unknown. METHODS: We conducted a multinational, single-group study that enrolled patients at risk for sudden death from ventricular arrhythmias and followed them for 6 months after implantation of a modular pacemaker-defibrillator system. The safety end point was freedom from leadless pacemaker-related major complications, evaluated against a performance goal of 86%. The two primary performance end points were successful communication between the pacemaker and the ICD (performance goal, 88%) and a pacing threshold of up to 2.0 V at a 0.4-msec pulse width (performance goal, 80%). RESULTS: We enrolled 293 patients, 162 of whom were in the 6-month end-point cohort and 151 of whom completed the 6-month follow-up period. The mean age of the patients was 60 years, 16.7% were women, and the mean (±SD) left ventricular ejection fraction was 33.1±12.6%. The percentage of patients who were free from leadless pacemaker-related major complications was 97.5%, which exceeded the prespecified performance goal. Wireless-device communication was successful in 98.8% of communication tests, which exceeded the prespecified goal. Of 151 patients, 147 (97.4%) had pacing thresholds of 2.0 V or less, which exceeded the prespecified goal. The percentage of episodes of arrhythmia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure. Of 162 patients, 8 died (4.9%); none of the deaths were deemed to be related to arrhythmias or the implantation procedure. CONCLUSIONS: The leadless pacemaker in wireless communication with a subcutaneous ICD exceeded performance goals for freedom from major complications related to the leadless pacemaker, for communication between the leadless pacemaker and subcutaneous ICD, and for the percentage of patients with a pacing threshold up to 2.0 V at a 0.4-msec pulse width at 6 months. (Funded by Boston Scientific; MODULAR ATP ClinicalTrials.gov NCT04798768.).

Predictive value of the PRAETORIAN score for defibrillation test success in patients with subcutaneous ICD: A subanalysis of the PRAETORIAN-DFT trial.

BACKGROUND: The PRAETORIAN score estimates the risk of failure of subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy by using generator and lead positioning on bidirectional chest radiographs. The PRospective randomized compArative trial of subcutanEous implanTable cardiOverter-defibrillatoR ImplANtation with and without DeFibrillation Testing (PRAETORIAN-DFT) investigates whether PRAETORIAN score calculation is noninferior to defibrillation testing (DFT) with regard to first shock efficacy in spontaneous events. OBJECTIVE: This prespecified subanalysis assessed the predictive value of the PRAETORIAN score for defibrillation success in induced ventricular arrhythmias. METHODS: This multicenter investigator-initiated trial randomized 965 patients between DFT and PRAETORIAN score calculation after de novo S-ICD implantation. Successful DFT was defined as conversion of induced ventricular arrhythmia in <5 seconds from shock delivery within 2 attempts. Bidirectional chest radiographs were obtained after implantation. The predictive value of the PRAETORIAN score for DFT success was calculated for patients in the DFT arm. RESULTS: In total, 482 patients were randomized to undergo DFT. Of these patients, 457 (95%) underwent DFT according to protocol, of whom 445 (97%) had successful DFT and 12 (3%) had failed DFT. A PRAETORIAN score of ≥90 had a positive predictive value of 25% for failed DFT, and a PRAETORIAN score of <90 had a negative predictive value of 99% for successful DFT. A PRAETORIAN score of ≥90 was the strongest independent predictor for failed DFT (odds ratio 33.77; confidence interval 6.13-279.95; P < .001). CONCLUSION: A PRAETORIAN score of <90 serves as a reliable indicator for DFT success in patients with S-ICD, and a PRAETORIAN score of ≥90 is a strong predictor for DFT failure.

Novel algorithms improve arrhythmia detection accuracy in insertable cardiac monitors.

INTRODUCTION: Insertable cardiac monitors (ICMs) are commonly used to diagnose cardiac arrhythmias. False detections in the latest ICM systems remain an issue, primarily due to inaccurate R-wave sensing. New discrimination algorithms were developed and tested to reduce false detections of atrial fibrillation (AF), pause, and tachycardia episodes in ICMs. METHODS: Stored electrograms (EGMs) of AF, pause, and tachycardia episodes detected by Abbott Confirm Rx™ ICMs were extracted from the Merlin.net™ Patient Care Network, and manually adjudicated to establish independent training and testing datasets. New discrimination algorithms were developed to reject false episodes due to inaccurate R-wave sensing, P-wave identification, and R-R interval patterns. The performance of these new algorithms was quantified by false positive reduction (FPR) and true positive maintenance (TPM), relative to the existing algorithms. RESULTS: The new AF detection algorithm was trained on 5911 EGMs from 744 devices, resulting in 66.9% FPR and 97.8% TPM. In the testing data set of 1354 EGMs from 119 devices, this algorithm achieved 45.8% FPR and 97.0% TPM. The new pause algorithm was trained on 7178 EGMs from 1490 devices, resulting in 70.9% FPR and 98.7% TPM. In the testing data set of 1442 EGMs from 340 devices, this algorithm achieved 74.4% FPR and 99.3% TPM. The new tachycardia algorithm was trained on 520 EGMs from 204 devices, resulting in 57.0% FPR and 96.6% TPM. In the testing data set of 459 EGMs from 237 devices, this algorithm achieved 57.9% FPR and 96.5% TPM. CONCLUSION: The new algorithms substantially reduced false AF, pause, and tachycardia episodes while maintaining the majority of true arrhythmia episodes detected by the Abbott ICM algorithms that exist today. Implementing these algorithms in the next-generation ICM systems may lead to improved detection accuracy, in-clinic efficiency, and device battery longevity.

Smartphone-based cardiac implantable electronic device remote monitoring: improved compliance and connectivity.

Aims: Remote monitoring (RM) is the standard of care for follow up of patients with cardiac implantable electronic devices. The aim of this study was to compare smartphone-based RM (SM-RM) using patient applications (myMerlinPulse™ app) with traditional bedside monitor RM (BM-RM). Methods and results: The retrospective study included de-identified US patients who received either SM-RM or BM-RM capable of implantable cardioverter defibrillators or cardiac resynchronization therapy defibrillators (Abbott, USA). Patients in SM-RM and BM-RM groups were propensity-score matched on age and gender, device type, implant year, and month. Compliance with RM was quantified as the proportion of patients enrolling in the RM system (Merlin.net™) and transmitting data at least once. Connectivity was measured by the median number of days between consecutive transmissions per patient. Of the initial 9714 patients with SM-RM and 26 679 patients with BM-RM, 9397 patients from each group were matched. Remote monitoring compliance was higher in SM-RM; significantly more patients with SM-RM were enrolled in RM compared with BM-RM (94.4 vs. 85.0%, P < 0.001), similar number of patients in the SM-RM group paired their device (95.1 vs. 95.0%, P = 0.77), but more SM-RM patients transmitted at least once (98.1 vs. 94.3%, P < 0.001). Connectivity was significantly higher in the SM-RM, with patients transmitting data every 1.2 (1.1, 1.7) vs. every 1.7 (1.5, 2.0) days with BM-RM (P < 0.001) and remained better over time. Significantly more SM-RM patients utilized patient-initiated transmissions compared with BM-RM (55.6 vs. 28.1%, P < 0.001). Conclusion: In this large real-world study, patients with SM-RM demonstrated improved compliance and connectivity compared with BM-RM.

Preliminary results from the LUX-Dx insertable cardiac monitor remote programming and performance (LUX-Dx PERFORM) study.

Despite the wide adoption of insertable cardiac monitors (ICMs), high false-positive rates, suboptimal signal quality, limited ability to detect atrial flutter, and lack of remote programming remain challenging. The LUX-Dx PERFORM study was designed to evaluate novel technologies engineered to address these issues. Here, we present preliminary results from the trial focusing on the safety of ICM insertion, remote monitoring rates, and the feasibility of remote programming. LUX-Dx PERFORM is a multicenter, prospective, single-arm, post-market, observational study with planned enrollment of up to 827 patients from 35 sites in North America. A preliminary cohort consisting of the first 369 patients who were enrolled between March and October 2021 was selected for analysis. Three hundred sixty-three (363) patients had ICM insertions across inpatient and outpatient settings. The mean time followed was 103.4 ± 61.8 days per patient. The total infection rate was 0.8% (3/363). Interim results show high levels of remote monitoring with a median 94% of days with data transmission (interquartile range: 82-99). Thirteen (13) in-clinic and 24 remote programming sessions were reported in 34 subjects. Reprogramming examples are presented to highlight signal quality, the ability to detect atrial flutter, and the positive impact of remote programming on patient management. Interim results from LUX-Dx PERFORM study demonstrate the safety of insertion, high data transmission rates, the ability to detect atrial flutter, and the feasibility of remote programming to optimize arrhythmia detection and improve clinical workflow. Future results from LUX-Dx PERFORM will further characterize improvements in signal quality and arrhythmia detection.

Next-generation Mobile Cardiac Telemetry: Clinical Value of Combining Electrocardiographic and Physiologic Parameters.

The ZOLL Arrhythmia Monitoring System, a mobile cardiac telemetry (MCT) device from ZOLL Corporation (Chelmsford, MA, USA), records single-channel electrocardiogram (ECG) signals, heart rate, activity, respiratory rate, and posture. Comprehensive reporting from these multiple biometrics may provide a global evaluation of arrhythmic or other cardiovascular risks in individual patients and insights into the patient's overall wellness and health status. The objective of the study was to evaluate the physician-perceived utility of adding biometric data to the traditional ECG-only-based assessment and subject-reported symptoms. This prospective study recruited candidates for MCT. Independent event and end-of-use (EOU) reports based on ECG and biometrics data were provided to physicians. To document whether the biometric data affected treatment plan decisions or added value over the ECG-alone data, physicians completed a questionnaire for each report. Additionally, they completed the questionnaire to understand the utility of the subject wellness information provided in the EOU report. From December 2020 to July 2021, 583 patients were enrolled by 27 physicians from 18 cardiology practices in the United States. When using biometrics data compared to the ECG alone, this study found that 96% of the physicians made changes to the treatment plan that initially was based on the ECG alone. The biometrics-based changes involved 64% of all patients (n = 535), and included modifications to medications, follow-up, and lifestyle in 18%, 19%, and 63% of the subjects, respectively. In this largest MCT study conducted to date, next-generation MCT, by providing multiple biometric parameters along with ECG data, improves physicians' ability to make patient management decisions. This added functionality and clarity may replace traditional "ECG with diary"-based monitoring.

Composite Index Tagging for PVI in Paroxysmal AF: A Prospective, Multicenter Postapproval Study.

BACKGROUND: VISITAG SURPOINT (VS)-guided ablation of paroxysmal atrial fibrillation has demonstrated good short- and long-term success rates with low rates of complications in recent, predominantly European, studies. However, there is a lack of multicenter data from the United States. OBJECTIVES: This U.S. study evaluated the safety and effectiveness of VS ablation using a contact force-sensing catheter for the treatment of drug-refractory symptomatic paroxysmal atrial fibrillation. METHODS: The prospective, nonrandomized VS postapproval study was conducted at 32 U.S. sites. Ablation consisted of pulmonary vein isolation with recommended VS index targets (anterior, roof, or ridge: 550; posterior or inferior: 380). Additional non-pulmonary vein triggers were ablated at the investigators' discretion. Subjects were followed for 12 months, including a 3-month blanking period. The primary safety endpoint was the primary adverse event rate up to 7 days postablation. The primary effectiveness endpoint was 12-month freedom from atrial tachyarrhythmia recurrence and an additional set of failure modes based on stringent monitoring (weekly transtelephonic monitoring [TTM] [day 91 through month 5], monthly TTM [months 6 to 12], and any symptomatic cardiac episode using TTM, plus electrocardiogram [at discharge, 1 month, 3 months, 6 months, and 12 months] with 24-hour Holter monitoring [12 months]). RESULTS: Of 283 patients enrolled, 261 had the catheter inserted and underwent ablation (safety cohort); 246 met all eligibility criteria (effectiveness cohort). Mean fluoroscopy time was 2.2 minutes. Mean amount of catheter-delivered fluid was 671 mL; only 18.0% of patients utilized a Foley catheter. Primary safety and effectiveness endpoints were met. The raw primary adverse event rate was 4.3% (14 events, n = 11). At 12 months, the Kaplan-Meier estimate of freedom from primary effectiveness failure was 76.4%; estimates of 12-month freedom from documented atrial fibrillation, atrial tachycardia, or atrial flutter recurrence were 81.5% and 92.7% per stringent monitoring and standard-of-care monitoring (excluding TTM), respectively. The first-pass isolation rate was 83.1%, represented by no acute reconnection after the 30-minute waiting period. Freedom from repeat ablation at 12 months was 94.0%. CONCLUSIONS: The VS postapproval study confirms reproducibility of clinical safety and effectiveness of the standardized VS paroxysmal atrial fibrillation ablation workflow with >80% 12-month freedom from atrial tachyarrhythmia recurrence and first-pass isolation rate of 83.1%. Procedures were performed with minimal fluoroscopy. (Evaluation of VISITAG SURPOINT™ Module With External Processing Unit [EPU]; NCT03624881).

Incidence of left atrial appendage thrombus despite 3 weeks of anticoagulation and the need for precardioversion echocardiography.

BACKGROUND: One of the most catastrophic complications of Atrial fibrillation (AF) is thromboembolic stroke. Current guidelines recommend that 3 weeks of anticoagulation is adequate prior to direct current cardioversion (DCCV) to prevent thromboembolism. Here we present data regarding, which anticoagulant is most likely to show a presence of an Left atrial appendage thrombus (LAAT) on trans esophageal echocardiogram (TEE) for DCCV despite 3 weeks of anticoagulation. OBJECTIVE: To investigate the effectiveness of both vitamin k antagonist (VKA) and direct oral anticoagulants (DOAC) in patients with AF as an anticoagulant for LAAT after 3 weeks of medication. METHODS: This is a single-high volume tertiary center, where TEE precardioversion is the standard practice. We reviewed data over 10 months where DCCV was intended on individuals with AF who were fully anticoagulated for at least 3 weeks with either a VKA or taking a DOAC. RESULTS: The data showed a statistical difference between patients who were fully anticoagulated for at least 3 weeks with VKA in comparison to DOACs. Patients on DOACs are significantly less likely to have an LAAT after at least 3 weeks of anticoagulation. OR = 0.04 (CI 95% 0.005-0.42; p-value < .05). Despite anticoagulation for at least 3 weeks, 40% of our patients still had a LAAT. CONCLUSION: Our data indicates that all patients should be required to undergo a TEE prior to DCCV. This data also adds to the current evidence and supports the use of DOAC in AF to prevent LAAT.

Reducing the electrogram review burden imposed by insertable cardiac monitors.

BACKGROUND: Insertable cardiac monitors (ICMs) are essential for ambulatory arrhythmia diagnosis. However, definitive diagnoses still require time-consuming, manual adjudication of electrograms (EGMs). OBJECTIVE: To evaluate the clinical impact of selecting only key EGMs for review. METHODS: Retrospective analyses of randomly selected Abbott Confirm Rx™ devices with ≥90 days of remote transmission history were performed, with each EGM adjudicated as true or false positive (TP, FP). For each device, up to 3 "key EGMs" per arrhythmia type per day were prioritized for review based on ventricular rate and episode duration. The reduction in EGMs and TP days (patient-days with at least one TP EGM), and any diagnostic delay (from the first TP), were calculated versus reviewing all EGMs. RESULTS: In 1000 ICMs over a median duration of 8.1 months, at least one atrial fibrillation (AF), tachycardia, bradycardia, or pause EGM was transmitted by 424, 343, 190, and 325 devices, respectively, with a total of 95 716 EGMs. Approximately 90% of episodes were contributed by 25% of patients. Key EGM selection reduced EGM review burden by 43%, 66%, 77%, and 50% (55% overall), while reducing TP days by 0.8%, 2.1%, 0.2%, and 0.0%, respectively. Despite reviewing fewer EGMs, 99% of devices with a TP EGM were ultimately diagnosed on the same day versus reviewing all EGMs. CONCLUSION: Key EGM selection reduced the EGM review substantially with no delay-to-diagnosis in 99% of patients exhibiting true arrhythmias. Implementing these rules in the Abbott patient care network may accelerate clinical workflow without compromising diagnostic timelines.

MultiPole pacing in non-responders to cardiac resynchronization therapy: Results from the QP ExCELs/MPP sub-study.

BACKGROUND: Multisite LV stimulation therapy allows for stimulation of two different left ventricular pacing vectors within a single LV lead and may improve responsiveness to cardiac resynchronization therapy (CRT). This study prospectively evaluated the safety and efficacy of the MultiPole Pacing (MPP) feature in CRT non-responder patients. METHODS AND RESULTS: CRT non-responders with a standard CRT-D indication were eligible for enrollment into the MPP Sub-Study. Patient status, NYHA classification, Patient Global Assessment (PGA), and adverse events were collected at follow-up. A clinical composite score (CCS) was determined at the 6 month follow-up visit. The primary objective was defined as the proportion of patients with an improved CCS. Safety was evaluated as freedom from MPP system related adverse events requiring additional invasive intervention to resolve. A total of 53 patients were enrolled across 26 U.S. centers. The cumulative follow-up duration was 24.1 years. CCS was improved in 35.6% of patients (p < .0001 when compared to a performance goal of 3%) after 6 months of MPP therapy. When incorporating patient feedback into a modified CCS, 60.0% of patients showed an improvement. Three patients (5.7%) experienced hospitalization for heart failure, and three patient deaths occurred over the follow-up period. No MPP system-related events were reported for an AE-free rate of 100% (95% CI 93.28% to 100.0%). CONCLUSIONS: The results of this small, non-randomized study suggest that the MPP feature is safe, and may be effective at converting a percentage of CRT non-responders to responders. Larger, randomized studies are needed to confirm this result.

Right Coronary Artery STEMI following Blunt Thoracic Trauma.

We present a case report of an otherwise healthy 37-year-old male without pertinent cardiac history or risk factors, who presented with cardiac trauma after a motor vehicle collision (MVC). Initial workup including electrocardiogram (ECG), transthoracic echocardiogram (TTE), and uptrending serial troponins warranted coronary angiography, during which occlusive thrombi were discovered in the proximal right coronary artery (pRCA), the right posterolateral vessel (rPL), and the right posterior descending artery (PDA). Subsequently, the patient underwent percutaneous coronary intervention of the RCA and PDA with aspiration thrombectomy. He was then initiated on dual antiplatelet therapy (DAPT) and recovered appropriately. This case is presented with the goal of enlightening the academic community of a rare complication while presenting a judicious approach to management in an attempt to decrease the occurrence of "near misses" in the future.

Ventricular activation patterns during intrinsic conduction and right ventricular pacing in cardiac resynchronization therapy patients.

BACKGROUND: Cardiac resynchronization therapy (CRT) involves stimulation of both right ventricle (RV) and left ventricle (LV). LV pacing from the sites of delayed electrical activation improves CRT response. The RV-LV conduction is typically measured in intrinsic rhythm. The differences in RV-LV conduction patterns and timing between intrinsic rhythm and during paced RV activation, these differences are not fully understood. METHODS: Enrolled patients were implanted with a de novo CRT device and quadripolar LV lead, with lead implant locations at the implanting physician's discretion. QRS duration and conduction delay between the RV lead and each of the four LV electrodes (D1, M2, M3, and P4) were measured during intrinsic conduction and RV pacing. RESULTS: Conduction measurements were collected from 275 patients across 14 international centers (68 ± 13 years of age, 73% male, 45% ischemic, 158 ± 22 ms QRS duration). Mean RV-LV conduction time was shorter during intrinsic conduction versus RV pacing by 59.6 ms (106.5 ± 36.5 versus 166.1 ± 32.1 ms, p < 0.001). The intra-LV activation delay between the latest and earliest activating LV electrode was also shorter during intrinsic conduction versus RV pacing by 6.6 ms (20.6 ± 13.1 vs. 27.2 ± 21.2 ms, p < 0.001). Intrinsic conduction and RV pacing resulted in a different activation order in 72.7% of patients, and the same LV activation order in 27.3%. CONCLUSIONS: Differences in RV-LV conduction time, intra-LV conduction time, and activation pattern were observed between intrinsic conduction and RV pacing. These findings highlight the importance of evaluating intrinsic versus paced ventricular activation to guide LV pacing site selection in CRT patients.

Vascular comorbidities worsen prognosis of patients with heart failure hospitalised with COVID-19.

BACKGROUND: Prior diagnosis of heart failure (HF) is associated with increased length of hospital stay (LOS) and mortality from COVID-19. Associations between substance use, venous thromboembolism (VTE) or peripheral arterial disease (PAD) and its effects on LOS or mortality in patients with HF hospitalised with COVID-19 remain unknown. OBJECTIVE: This study identified risk factors associated with poor in-hospital outcomes among patients with HF hospitalised with COVID-19. METHODS: Case-control study was conducted of patients with prior diagnosis of HF hospitalised with COVID-19 at an academic tertiary care centre from 1 January 2020 to 28 February 2021. Patients with HF hospitalised with COVID-19 with risk factors were compared with those without risk factors for clinical characteristics, LOS and mortality. Multivariate regression was conducted to identify multiple predictors of increased LOS and in-hospital mortality in patients with HF hospitalised with COVID-19. RESULTS: Total of 211 patients with HF were hospitalised with COVID-19. Women had longer LOS than men (9 days vs 7 days; p<0.001). Compared with patients without PAD or ischaemic stroke, patients with PAD or ischaemic stroke had longer LOS (7 days vs 9 days; p=0.012 and 7 days vs 11 days, p<0.001, respectively). Older patients (aged 65 and above) had increased in-hospital mortality compared with younger patients (adjusted OR: 1.04; 95% CI 1.00 to 1.07; p=0.036). Prior diagnosis of VTE increased mortality more than threefold in patients with HF hospitalised with COVID-19 (adjusted OR: 3.33; 95% CI 1.29 to 8.43; p=0.011). CONCLUSION: Vascular diseases increase LOS and mortality in patients with HF hospitalised with COVID-19.

Long-Term Outcome of Left Atrial Voltage-Guided Substrate Ablation During Atrial Fibrillation: A Novel Adjunctive Ablation Strategy.

INTRODUCTION: Left atrium (LA) low voltage area (LVA) on 3-D electroanatomic bipolar voltage mapping (EAVM), as a surrogate for scar, is associated with poor AF ablation outcome. We evaluated the long-term outcome of an LVA-guided atrial fibrillation (AF) substrate modification strategy as an adjunct to pulmonary vein isolation (PVI). METHODS AND RESULTS: Two hundred and one consecutive patients with AF (82% persistent/Non-PAF, age 65 years), who underwent EAVM during AF prior to PVI, were divided into 2 groups according to the presence or absence of LVA outside the PV antra, defined as bipolar voltage of <0.5 mV. LVA-guided substrate modification was performed after PVI in patients with LVA. LVA was found in 159 patients (79%). Non-PAF (OR 3.851, P = 0.002) and CHA2 DS2 -VASc score (OR 1.815, P < 0.001) were independent predictors for the LVA. After the index procedure, 144 patients (72%) were free from AF at 12 months. With multiple procedures, 148 patients (74%) during a median follow-up of 3.1 years were free from the recurrence. There was no difference in the recurrence (log-rank P = 0.746), and complications (0% vs. 7%, P = 0.125) between the groups. Neither LVA nor Non-PAF was an independent predictor for the recurrence in a multivariate analysis. CONCLUSIONS: Patients with LVA had an equally favorable long-term ablation outcome compared to those without. As an adjunct to PVI, voltage-guided substrate modification may be an important ablation strategy in patients with LA structural remodeling.

Correlation of Left Atrial Voltage Distribution Between Sinus Rhythm and Atrial Fibrillation: Identifying Structural Remodeling by 3-D Electroanatomic Mapping Irrespective of the Rhythm.

INTRODUCTION: Left atrial (LA) electroanatomical voltage mapping (EAVM) correlates with scar on LGE-MRI and has been used to guide ablation of low voltage area (LVA) in sinus rhythm (SR). We compared EAVM in SR and AF in a cohort of AF patients, and in SR between patients with AF and without AF or structural heart disease (control). METHODS AND RESULTS: Twenty-seven AF patients, 9 with paroxysmal AF (PAF), underwent point-by-point EAVM during SR and AF using same Carto3 geometry. Only adjacent SR-AF points (≤ 5 mm apart) were compared. In addition, 6 control patients were evaluated. There was a linear bipolar voltage correlation between SR and AF (r = 0.707, P < 0.001, Y = 1.515X + 0.786). LA bipolar voltage in patients with PAF was higher than those with Non-PAF in SR (2.24 ± 1.51 vs. 1.56 ± 1.53 mV) and AF (0.81 ± 0.60 vs. 0.58 ± 0.62 mV, both for P < 0.001). The pulmonary vein antra voltage was significantly lower than other LA regions in PAF (1.28 ± 0.79 vs. 2.54 ± 1.50 mV, P < 0.001) and Non-PAF patients (1.13 ± 1.04 vs. 1.86 ± 1.72 mV, P < 0.001), while no voltage differences was found in the control group (P = 0.998). CONCLUSION: There was a linear voltage correlation between SR and AF, suggesting a similar extent of LA fibrotic substrate can be identified on EAVM by adjusting the voltage cutoff. Structural remodeling starts in the PV antra and may progress to other LA regions.

Bilateral Pneumothoraces Following BiV ICD Placement: A Case of Buffalo Chest Syndrome.

BACKGROUND: Contralateral pneumothorax following device implantation on the left side has been reported in a few cases. The majority of contralateral pneumothoraces showed evidence of atrial perforation on computed tomography (CT), echocardiography, or chest x-rays and required lead revision. To the best of our knowledge there is only 1 other reported case of contralateral pneumothorax without evidence of macro-displacement of the atrial lead. In that case the patient experienced a right-sided pneumothorax on day 1 after undergoing repositioning of the atrial lead. CASE REPORT: The current case is unique on several accounts, including timing of the contralateral pneumothorax and no evidence of associated atrial lead perforation on device interrogation or CT imaging. Furthermore, the appearance of contralateral pneumothorax within 8 hours of clamping of the ipsilateral chest tube argues in favor of a pleuro-pleural fistula. CONCLUSIONS: The term 'buffalo chest' refers to a single pleural space, with no anatomical separation of the 2 hemithoraces, as seen in an American buffalo or bison. We believe this to be a case of buffalo chest syndrome.

Fever of unknown origin: a case of cardiac myxoma infected with Staphylococcus lugdunensis.

Infected cardiac myxoma is a rare entity. It poses a diagnostic challenge as clinical presentation may reflect an underlying infectious, immune, or a neoplastic disease process. To the best of our knowledge, the first case of a cardiac myxoma infected with Staphylococcus lugdunensis is reported in a 54-year-old man with fever of unknown origin for 4 months. Successful excision of the tumor was performed and was followed by an uneventful recovery. Clinical presentation, diagnosis, and management of infected cardiac myxomas are discussed.

An electronic hand hygiene surveillance device: a pilot study exploring surrogate markers for hand hygiene compliance.

OBJECTIVE: To evaluate the feasibility of using an electronic hand hygiene surveillance and feedback monitoring device. DESIGN: A 2-phase pilot study included initial direct observation of hand hygiene practices as part of routine hospital quality assurance (phase I) and subsequent monitoring using an electronic hand hygiene surveillance device (phase II). SETTING: A 700-bed tertiary care teaching hospital. PARTICIPANTS: Phase I included a convenience sample of healthcare workers. Phase II included 7 medical interns and 7 registered nurses recruited through email and at work-related meetings. METHODS: During phase I, healthcare workers were directly observed at patient room entry and exit during the period April through November 2008. During phase II, hand hygiene data were gathered through indirect observation using the electronic device during a 4-week period in August 2009. Twenty patient rooms were fitted with electronic trigger devices that signaled a reader unit worn by participants when they entered the room, and 70 dispensers for liquid soap or hand sanitizer were fitted with triggers that signaled the reader unit when the dispenser was used. The accuracy of the devices was checked by the principal investigator, who manually recorded his room entries and exits and dispenser use while wearing a reader unit. RESULTS: During phase I, hand hygiene occurred before room entry for 95 (25.1%) and after room exit for 149 (39.4%) of 378 directly observed patient room visits, for a cumulative composite compliance rate of 32.3%. Among the 378 room visits, 347 (91.8%) involved contact with the patient and/or environment. During phase II, electronic monitoring revealed a cumulative composite compliance rate of 25.5%. The electronic device captured 61 (98%) of 62 manually recorded room entries and 133 (95%) of 140 manually recorded dispensing events. CONCLUSIONS: The electronic hand hygiene surveillance device seems to be a practical method for routinely monitoring hand hygiene compliance in healthcare workers.

Correlation between clinical and histological findings in parathyroid tumors suspicious for carcinoma.

Carcinoma of the parathyroid is a rare malignancy that can be cured surgically if the proper diagnosis and treatment is given initially. Arriving to the clinical suspicion of a malignancy preoperatively is by far the most important step for a good prognosis. Our goal is to review the correlation between clinical and final histopathological findings that can arouse the suspicion of such malignancy and their true predictive value in the diagnosis. All patients that underwent surgical removal of the parathyroid mass between March of 1992 and March of 2003 were reviewed retrospectively at Providence Hospital and Medical Centers. Among 168 patients who underwent parathyroid excision, 14 (8.3%) had hyperplasia of the parathyroid, 121 (72%) had benign adenoma, 25 (14.8%) had other benign lesions, and 8 (4.7%) patients had primary carcinoma of the parathyroid confirmed by pathology. Our mean serum calcium level was 11.57 mg/dL, which was lower than the mean level (12 mg/dL) for benign hyperparathyroidism. The mean tumor size was 2.18 cm, smaller than the proposed for malignant criteria, and none of the eight patients (0%) had any symptoms of hypercalcemia at the time of diagnosis. Seven of eight patients (87.5%) had frank signs of invasion together with other histological features, and two patients had associated papillary carcinoma of the thyroid. Five patients from our series did not meet clinical criteria for malignancy (tumor size > 3 cm, palpable mass, and serum calcium > 14 mg/dL), but had undisputable histological findings (high mitotic pattern, fibrous trabeculae, capsular invasion, vascular invasion, and nodular involvement). On the other hand, 17 patients with benign histology had tumors greater than 3 cm, and an additional 18 had palpable masses on physical examination. We believe that these patients need to be followed closely. The patients with diagnosis of parathyroid carcinoma, their kindred, and those with large adenomas may benefit from genetic screening for HRTP2 gene mutations in search of early detection of tumors suspicious for malignancy. This is based on the fact that we did not find correlation between the clinical presentation and the histological features in our patients with proven malignancy.