ECG Interpretation Proficiency of Healthcare Professionals.

ECG interpretation is essential in modern medicine, yet achieving and maintaining competency can be challenging for healthcare professionals. Quantifying proficiency gaps can inform educational interventions for addressing these challenges. Medical professionals from diverse disciplines and training levels interpreted 30 12-lead ECGs with common urgent and nonurgent findings. Average accuracy (percentage of correctly identified findings), interpretation time per ECG, and self-reported confidence (rated on a scale of 0 [not confident], 1 [somewhat confident], or 2 [confident]) were evaluated. Among the 1206 participants, there were 72 (6%) primary care physicians (PCPs), 146 (12%) cardiology fellows-in-training (FITs), 353 (29%) resident physicians, 182 (15%) medical students, 84 (7%) advanced practice providers (APPs), 120 (10%) nurses, and 249 (21%) allied health professionals (AHPs). Overall, participants achieved an average overall accuracy of 56.4% ± 17.2%, interpretation time of 142 ± 67 seconds, and confidence of 0.83 ± 0.53. Cardiology FITs demonstrated superior performance across all metrics. PCPs had a higher accuracy compared to nurses and APPs (58.1% vs 46.8% and 50.6%; P < 0.01), but a lower accuracy than resident physicians (58.1% vs 59.7%; P < 0.01). AHPs outperformed nurses and APPs in every metric and showed comparable performance to resident physicians and PCPs. Our findings highlight significant gaps in the ECG interpretation proficiency among healthcare professionals.

Education curriculum assessment for teaching electrocardiography: Rationale and design for the prospective, international, randomized controlled EDUCATE trial.

BACKGROUND: Electrocardiogram (ECG) interpretation training is a fundamental component of medical education across disciplines. However, the skill of interpreting ECGs is not universal among medical graduates, and numerous barriers and challenges exist in medical training and clinical practice. An evidence-based and widely accessible learning solution is needed. DESIGN: The EDUcation Curriculum Assessment for Teaching Electrocardiography (EDUCATE) Trial is a prospective, international, investigator-initiated, open-label, randomized controlled trial designed to determine the efficacy of self-directed and active-learning approaches of a web-based educational platform for improving ECG interpretation proficiency. Target enrollment is 1000 medical professionals from a variety of medical disciplines and training levels. Participants will complete a pre-intervention baseline survey and an ECG interpretation proficiency test. After completion, participants will be randomized into one of four groups in a 1:1:1:1 fashion: (i) an online, question-based learning resource, (ii) an online, lecture-based learning resource, (iii) an online, hybrid question- and lecture-based learning resource, or (iv) a control group with no ECG learning resources. The primary endpoint will be the change in overall ECG interpretation performance according to pre- and post-intervention tests, and it will be measured within and compared between medical professional groups. Secondary endpoints will include changes in ECG interpretation time, self-reported confidence, and interpretation accuracy for specific ECG findings. CONCLUSIONS: The EDUCATE Trial is a pioneering initiative aiming to establish a practical, widely available, evidence-based solution to enhance ECG interpretation proficiency among medical professionals. Through its innovative study design, it tackles the currently unaddressed challenges of ECG interpretation education in the modern era. The trial seeks to pinpoint performance gaps across medical professions, compare the effectiveness of different web-based ECG content delivery methods, and create initial evidence for competency-based standards. If successful, the EDUCATE Trial will represent a significant stride towards data-driven solutions for improving ECG interpretation skills in the medical community.

Electrocardiographic Correlates of Acute Allograft Rejection Among Heart Transplant Recipients.

BACKGROUND: Acute allograft rejection appears to be associated with increases in QT/QTc intervals. OBJECTIVES: To determine the relationship between acute allograft rejection and electrocardiogram changes in patients undergoing an orthotopic heart transplant. METHODS: The study population comprised 220 adult patients undergoing heart transplant and enrolled in the NEW HEART study. Electrocardiograms obtained within 72 hours of endomyocardial biopsy were analyzed; electrocardiograms obtained fewer than 10 days after transplant surgery were excluded. Repeated-measures analysis was performed with statistical models including effects for rejection severity (mild and moderate/severe) and time trends independent of rejection status. RESULTS: The 151 male and 69 female transplant recipients (mean age [SD], 54 [13] years) had 969 biopsy/electrocardiogram pairs: 677 with no rejection, 280 with mild rejection, and 12 with moderate/severe rejection. Moderate to severe organ rejection was associated with significant increases in QRS duration (P < .001), QT (P = .009), QTc (P = .003), and PR interval (P = .03), as well as increased odds of right bundle block branch (P = .002) and fascicular block (P = .009) occurring. CONCLUSIONS: Moderate to severe acute allograft rejection was associated with electrocardiographic changes after transplant surgery. Studies are needed to assess the value of computerized electrocardiogram measurement algorithms for detecting acute allograft rejection.

Understanding heart rate alarm adjustment in the intensive care units through an analytical approach.

BACKGROUND: Heart rate (HR) alarms are prevalent in ICU, and these parameters are configurable. Not much is known about nursing behavior associated with tailoring HR alarm parameters to individual patients to reduce clinical alarm fatigue. OBJECTIVES: To understand the relationship between heart rate (HR) alarms and adjustments to reduce unnecessary heart rate alarms. METHODS: Retrospective, quantitative analysis of an adjudicated database using analytical approaches to understand behaviors surrounding parameter HR alarm adjustments. Patients were sampled from five adult ICUs (77 beds) over one month at a quaternary care university medical center. A total of 337 of 461 ICU patients had HR alarms with 53.7% male, mean age 60.3 years, and 39% non-Caucasian. Default HR alarm parameters were 50 and 130 beats per minute (bpm). The occurrence of each alarm, vital signs, and physiologic waveforms was stored in a relational database (SQL server). RESULTS: There were 23,624 HR alarms for analysis, with 65.4% exceeding the upper heart rate limit. Only 51% of patients with HR alarms had parameters adjusted, with a median upper limit change of +5 bpm and -1 bpm lower limit. The median time to first HR parameter adjustment was 17.9 hours, without reduction in alarms occurrence (p = 0.57). CONCLUSIONS: HR alarms are prevalent in ICU, and half of HR alarm settings remain at default. There is a long delay between HR alarms and parameters changes, with insufficient changes to decrease HR alarms. Increasing frequency of HR alarms shortens the time to first adjustment. Best practice guidelines for HR alarm limits are needed to reduce alarm fatigue and improve monitoring precision.

ECG-derived Cheyne-Stokes respiration and periodic breathing in healthy and hospitalized populations.

BACKGROUND: Cheyne-Stokes respiration (CSR) has been investigated primarily in outpatients with heart failure. In this study we compare CSR and periodic breathing (PB) between healthy and cardiac groups. METHODS: We compared CSR and PB, measured during 24 hr of continuous 12-lead electrocardiographic (ECG) Holter recording, in a group of 90 hospitalized patients presenting to the emergency department with symptoms suggestive of acute coronary syndrome (ACS) to a group of 100 healthy ambulatory participants. We also examined CSR and PB in the 90 patients presenting with ACS symptoms, divided into a group of 39 (43%) with confirmed ACS, and 51 (57%) with a cardiac diagnosis but non-ACS. SuperECG software was used to derive respiration and then calculate CSR and PB episodes from the ECG Holter data. Regression analyses were used to analyze the data. We hypothesized SuperECG software would differentiate between the groups by detecting less CSR and PB in the healthy group than the group of patients presenting to the emergency department with ACS symptoms. RESULTS: Hospitalized patients with suspected ACS had 7.3 times more CSR episodes and 1.6 times more PB episodes than healthy ambulatory participants. Patients with confirmed ACS had 6.0 times more CSR episodes and 1.3 times more PB episodes than cardiac non-ACS patients. CONCLUSION: Continuous 12-lead ECG derived CSR and PB appear to differentiate between healthy participants and hospitalized patients.

Association of Implementation of Practice Standards for Electrocardiographic Monitoring With Nurses' Knowledge, Quality of Care, and Patient Outcomes: Findings From the Practical Use of the Latest Standards of Electrocardiography (PULSE) Trial.

BACKGROUND: Although continuous electrocardiographic (ECG) monitoring is ubiquitous in hospitals, monitoring practices are inconsistent. We evaluated implementation of American Heart Association practice standards for ECG monitoring on nurses' knowledge, quality of care, and patient outcomes. METHODS AND RESULTS: The PULSE (Practical Use of the Latest Standards of Electrocardiography) Trial was a 6-year multisite randomized clinical trial with crossover that took place in 65 cardiac units in 17 hospitals. We measured outcomes at baseline, time 2 after group 1 hospitals received the intervention, and time 3 after group 2 hospitals received the intervention. Measurement periods were 15 months apart. The 2-part intervention consisted of an online ECG monitoring education program and strategies to implement and sustain change in practice. Nurses' knowledge (N=3013 nurses) was measured by a validated 20-item online test, quality of care related to ECG monitoring (N=4587 patients) by on-site observation, and patient outcomes (mortality, in-hospital myocardial infarction, and not surviving a cardiac arrest; N=95 884 hospital admissions) by review of administrative, laboratory, and medical record data. Nurses' knowledge improved significantly immediately after the intervention in both groups but was not sustained 15 months later. For most measures of quality of care (accurate electrode placement, accurate rhythm interpretation, appropriate monitoring, and ST-segment monitoring when indicated), the intervention was associated with significant improvement, which was sustained 15 months later. Of the 3 patient outcomes, only in-hospital myocardial infarction declined significantly after the intervention and was sustained. CONCLUSIONS: Online ECG monitoring education and strategies to change practice can lead to improved nurses' knowledge, quality of care, and patient outcomes. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01269736.

Clinical and gender differences in heart transplant recipients in the NEW HEART study.

BACKGROUND: Little attention has focused on gender differences in cardiac comorbidities and outcomes in patients undergoing orthotropic heart transplant. OBJECTIVE: The objective of this study was to investigate gender differences at baseline and during follow-up among heart transplant patients. METHODS: An observational cohort within the NEW HEART study was evaluated to determine gender differences in relation to age, coexisting cardiac comorbidities, and outcomes. Differences were assessed by t-test, Fisher's exact test, and logistic regression analysis. RESULTS: Male transplant recipients ( n = 238) were significantly older than female recipients ( n = 92), with a greater percentage over 60 years of age (45% vs. 24%, p = 0.0006). Males were more likely to have hypertension (63% vs. 49%, p = 0.034), dyslipidemia (62% vs. 45%, p = 0.006), a history of smoking (52% vs. 35%, p = 0.009), and diabetes (42% vs. 21%, p = 0.0002). Analysis of endomyocardial biopsies obtained during the 1-year follow-up period demonstrated that women averaged more episodes of acute rejection than men (3.9 vs. 3.0, p = 0.009). While most episodes of rejection were mild, women were more likely than men to have episodes of moderate or severe rejection (14% vs. 5%, p = 0.012) and to be hospitalized for acute rejection (15% vs. 6%, p = 0.013). There were no significant differences in mortality. CONCLUSIONS: Men were more likely than women to be older and to have diabetes, dyslipidemia, hypertension, and a history of smoking. Women were more likely to experience moderate or severe allograft rejection and to be hospitalized for acute rejection. Future investigation of the reasons for these gender differences is warranted and may improve clinical care of women undergoing cardiac transplantation.

Utility of Conventional Electrocardiographic Criteria in Patients With Idiopathic Ventricular Tachycardia.

OBJECTIVES: This study sought to determine the ability of conventional electrocardiographic (ECG) criteria to correctly differentiate idiopathic ventricular tachycardia (VT) from supraventricular tachycardia (SVT) with aberrancy. BACKGROUND: Previously reported VT ECG criteria were developed from cohorts of patients with structural heart disease and have not been applied to patients with idiopathic VT. METHODS: ECGs of 115 idiopathic VTs, 101 post-myocardial infarction (MI) VTs, and 111 wide QRS SVTs were analyzed using standard criteria. VT was diagnosed in patients when at least 1 criterion was met, SVT when no criteria were met, and indeterminate when there were conflicting criteria. RESULTS: Standard ECG criteria more frequently diagnosed VT in the post-MI group than the idiopathic group (95% vs. 82%, respectively; p < 0.01). Diagnosis in only 12 of the 111 SVT patients (11%) met the criteria for VT. All patients in the idiopathic VT group with right branch bundle block morphology who did not meet VT criteria demonstrated an rsR' pattern in V1 (consistent with SVT). Among idiopathic VT patients, Purkinje-associated VT had the lowest sensitivity for correct VT diagnosis in 13 of 23 patients (57%), septal sites of origin were correctly diagnosed in only 56 of 76 patients (74%), whereas nonseptal sites had a high sensitivity in 35 of 35 patients (100%; p < 0.005). CONCLUSIONS: Conventional ECG criteria have reduced sensitivity to distinguish VT from SVT with aberrancy in patients with idiopathic VT. This is most pronounced in VT originating from septal sites, particularly Purkinje sites and the septal outflow tract regions. Clinicians should be aware that application of conventional ECG criteria in idiopathic VT may underdiagnose VT.

In memoriam: A tribute to the work and lives of Ron Selvester and Rory Childers.

At the April, 2015 International Society for Computerized Electrocardiology (ISCE) Annual Conference in San Jose, CA, a special session entitled Remembering Ron & Rory was held to pay tribute to the extraordinary work and lives of two experts in electrocardiology. The session was well attended by conference attendees, Childers' family members and friends, and additional colleagues who traveled to San Jose solely to participate in this session. The purpose of the present paper is to document the spirit of this special session as faithfully as possible using the words of the session speakers.

Computer-assisted interventions to improve QTc documentation in patients receiving QT-prolonging drugs.

BACKGROUND: Many medications commonly used in hospitals can cause prolonged corrected QT interval (QTc), putting patients at risk for torsade de pointes (TdP), a potentially fatal arrhythmia. However, documentation of QTc for hospitalized patients receiving QT-prolonging medications is often not consistent with American Heart Association standards. OBJECTIVE: To examine effects of education and computerized documentation enhancements on QTc documentation. METHODS: A quasi-experimental multisite study among 4011 cardiac-monitored patients receiving QTc-prolonging medications within a 10-hospital health care system was conducted to compare QTc documentation before (n=1517), 3 months after (n = 1301), and 4 to 6 months after (n = 1193) an intervention. The intervention included (1) online education for 3232 nurses, (2) electronic notifications to alert nurses when a patient received at least 2 doses of a QT-prolonging medication, and (3) computerized calculation of QTc in electronic health records after nurses had documented heart rate and QT interval. RESULTS: QTc documentation for inpatients receiving QTc-prolonging drugs increased significantly from baseline (17.3%) to 3 months after the intervention (58.2%; P < .001) within the 10 hospitals and had increased further 4 to 6 months after the intervention (62.1%, P = .75). Patients at larger hospitals were significantly more likely to have their QTc documented (46.4%) than were patients at smaller hospitals (26.2%; P < .001). CONCLUSION: A 3-step system-wide intervention was associated with an increase in QTc documentation for patients at risk for drug-induced TdP, and improvements persisted over time. Further study is needed to assess whether increased QTc documentation decreases occurrence of drug-induced TdP. (American Journal of Critical Care. 2015;24:e6-e15).

Normal prehospital electrocardiography is linked to long-term survival in patients presenting to the emergency department with symptoms of acute coronary syndrome.

AIMS/METHODS: We studied 735 patients who activated "911" for chest pain and/or anginal equivalent symptoms and received 12-lead ECG monitoring with specialized ischemia monitoring software in the ambulance. Prehospital electrocardiograms (PH ECG) were analyzed to determine the proportion of patients who present with completely normal PH ECG findings (absence of ischemia/infarction, arrhythmia, or any other abnormality) and to compare outcomes among patients with and without any PH ECG abnormality. RESULTS: Of 735 patients (mean age 70.5, 52.4% male), 68 (9.3%) patients had completely normal PH ECG findings. They experienced significantly less adverse hospital outcomes (12% vs 37%), length of stay (1.19 vs 3.86 days), and long-term mortality (9% vs 28%) than those with any PH ECG abnormality (p<.05). CONCLUSION: Normal PH ECG findings are associated with better short and long-term outcomes in ambulance patients with ischemic symptoms. These findings may enhance early triage and risk stratification in emergency cardiac care.

Integrating monitor alarms with laboratory test results to enhance patient deterioration prediction.

Patient monitors in modern hospitals have become ubiquitous but they generate an excessive number of false alarms causing alarm fatigue. Our previous work showed that combinations of frequently co-occurring monitor alarms, called SuperAlarm patterns, were capable of predicting in-hospital code blue events at a lower alarm frequency. In the present study, we extend the conceptual domain of a SuperAlarm to incorporate laboratory test results along with monitor alarms so as to build an integrated data set to mine SuperAlarm patterns. We propose two approaches to integrate monitor alarms with laboratory test results and use a maximal frequent itemsets mining algorithm to find SuperAlarm patterns. Under an acceptable false positive rate FPRmax, optimal parameters including the minimum support threshold and the length of time window for the algorithm to find the combinations of monitor alarms and laboratory test results are determined based on a 10-fold cross-validation set. SuperAlarm candidates are generated under these optimal parameters. The final SuperAlarm patterns are obtained by further removing the candidates with false positive rate>FPRmax. The performance of SuperAlarm patterns are assessed using an independent test data set. First, we calculate the sensitivity with respect to prediction window and the sensitivity with respect to lead time. Second, we calculate the false SuperAlarm ratio (ratio of the hourly number of SuperAlarm triggers for control patients to that of the monitor alarms, or that of regular monitor alarms plus laboratory test results if the SuperAlarm patterns contain laboratory test results) and the work-up to detection ratio, WDR (ratio of the number of patients triggering any SuperAlarm patterns to that of code blue patients triggering any SuperAlarm patterns). The experiment results demonstrate that when varying FPRmax between 0.02 and 0.15, the SuperAlarm patterns composed of monitor alarms along with the last two laboratory test results are triggered at least once for [56.7-93.3%] of code blue patients within an 1-h prediction window before code blue events and for [43.3-90.0%] of code blue patients at least 1-h ahead of code blue events. However, the hourly number of these SuperAlarm patterns occurring in control patients is only [2.0-14.8%] of that of regular monitor alarms with WDR varying between 2.1 and 6.5 in a 12-h window. For a given FPRmax threshold, the SuperAlarm set generated from the integrated data set has higher sensitivity and lower WDR than the SuperAlarm set generated from the regular monitor alarm data set. In addition, the McNemar's test also shows that the performance of the SuperAlarm set from the integrated data set is significantly different from that of the SuperAlarm set from the regular monitor alarm data set. We therefore conclude that the SuperAlarm patterns generated from the integrated data set are better at predicting code blue events.

Insights into the problem of alarm fatigue with physiologic monitor devices: a comprehensive observational study of consecutive intensive care unit patients.

PURPOSE: Physiologic monitors are plagued with alarms that create a cacophony of sounds and visual alerts causing "alarm fatigue" which creates an unsafe patient environment because a life-threatening event may be missed in this milieu of sensory overload. Using a state-of-the-art technology acquisition infrastructure, all monitor data including 7 ECG leads, all pressure, SpO(2), and respiration waveforms as well as user settings and alarms were stored on 461 adults treated in intensive care units. Using a well-defined alarm annotation protocol, nurse scientists with 95% inter-rater reliability annotated 12,671 arrhythmia alarms. RESULTS: A total of 2,558,760 unique alarms occurred in the 31-day study period: arrhythmia, 1,154,201; parameter, 612,927; technical, 791,632. There were 381,560 audible alarms for an audible alarm burden of 187/bed/day. 88.8% of the 12,671 annotated arrhythmia alarms were false positives. Conditions causing excessive alarms included inappropriate alarm settings, persistent atrial fibrillation, and non-actionable events such as PVC's and brief spikes in ST segments. Low amplitude QRS complexes in some, but not all available ECG leads caused undercounting and false arrhythmia alarms. Wide QRS complexes due to bundle branch block or ventricular pacemaker rhythm caused false alarms. 93% of the 168 true ventricular tachycardia alarms were not sustained long enough to warrant treatment. DISCUSSION: The excessive number of physiologic monitor alarms is a complex interplay of inappropriate user settings, patient conditions, and algorithm deficiencies. Device solutions should focus on use of all available ECG leads to identify non-artifact leads and leads with adequate QRS amplitude. Devices should provide prompts to aide in more appropriate tailoring of alarm settings to individual patients. Atrial fibrillation alarms should be limited to new onset and termination of the arrhythmia and delays for ST-segment and other parameter alarms should be configurable. Because computer devices are more reliable than humans, an opportunity exists to improve physiologic monitoring and reduce alarm fatigue.

Heart rate variability measured early in patients with evolving acute coronary syndrome and 1-year outcomes of rehospitalization and mortality.

OBJECTIVE: This study sought to examine the prognostic value of heart rate variability (HRV) measurement initiated immediately after emergency department presentation for patients with acute coronary syndrome (ACS). BACKGROUND: Altered HRV has been associated with adverse outcomes in heart disease, but the value of HRV measured during the earliest phases of ACS related to risk of 1-year rehospitalization and death has not been established. METHODS: Twenty-four-hour Holter recordings of 279 patients with ACS were initiated within 45 minutes of emergency department arrival; recordings with ≥18 hours of sinus rhythm were selected for HRV analysis (number [N] =193). Time domain, frequency domain, and nonlinear HRV were examined. Survival analysis was performed. RESULTS: During the 1-year follow-up, 94 patients were event-free, 82 were readmitted, and 17 died. HRV was altered in relation to outcomes. Predictors of rehospitalization included increased normalized high frequency power, decreased normalized low frequency power, and decreased low/high frequency ratio. Normalized high frequency >42 ms(2) predicted rehospitalization while controlling for clinical variables (hazard ratio [HR] =2.3; 95% confidence interval [CI] =1.4-3.8, P=0.001). Variables significantly associated with death included natural logs of total power and ultra low frequency power. A model with ultra low frequency power <8 ms(2) (HR =3.8; 95% CI =1.5-10.1; P=0.007) and troponin >0.3 ng/mL (HR =4.0; 95% CI =1.3-12.1; P=0.016) revealed that each contributed independently in predicting mortality. Nonlinear HRV variables were significant predictors of both outcomes. CONCLUSION: HRV measured close to the ACS onset may assist in risk stratification. HRV cut-points may provide additional, incremental prognostic information to established assessment guidelines, and may be worthy of additional study.

False ventricular tachycardia alarm suppression in the ICU based on the discrete wavelet transform in the ECG signal.

Over the past few years, reducing the number of false positive cardiac monitor alarms (FA) in the intensive care unit (ICU) has become an issue of the utmost importance. In our work, we developed a robust methodology that, without the need for additional non-ECG waveforms, suppresses false positive ventricular tachycardia (VT) alarms without resulting in false negative alarms. Our approach is based on features extracted from the ECG signal 20 seconds prior to a triggered alarm. We applied a multi resolution wavelet transform to the ECG data 20seconds prior to the alarm trigger, extracted features from appropriately chosen scales and combined them across all available leads. These representations are presented to a L1-regularized logistic regression classifier. Results are shown in two datasets of physiological waveforms with manually assessed cardiac monitor alarms: the MIMIC II dataset, where we achieved a false alarm (FA) suppression of 21% with zero true alarm (TA) suppression; and a dataset compiled by UCSF and General Electric, where a 36% FA suppression was achieved with a zero TA suppression. The methodology described in this work could be implemented to reduce the number of false monitor alarms in other arrhythmias.

Heart rate variability measurement and clinical depression in acute coronary syndrome patients: narrative review of recent literature.

AIM: We aimed to explore links between heart rate variability (HRV) and clinical depression in patients with acute coronary syndrome (ACS), through a review of recent clinical research literature. BACKGROUND: Patients with ACS are at risk for both cardiac autonomic dysfunction and clinical depression. Both conditions can negatively impact the ability to recover from an acute physiological insult, such as unstable angina or myocardial infarction, increasing the risk for adverse cardiovascular outcomes. HRV is recognized as a reflection of autonomic function. METHODS: A narrative review was undertaken to evaluate state-of-the-art clinical research, using the PubMed database, January 2013. The search terms "heart rate variability" and "depression" were used in conjunction with "acute coronary syndrome", "unstable angina", or "myocardial infarction" to find clinical studies published within the past 10 years related to HRV and clinical depression, in patients with an ACS episode. Studies were included if HRV measurement and depression screening were undertaken during an ACS hospitalization or within 2 months of hospital discharge. RESULTS: Nine clinical studies met the inclusion criteria. The studies' results indicate that there may be a relationship between abnormal HRV and clinical depression when assessed early after an ACS event, offering the possibility that these risk factors play a modest role in patient outcomes. CONCLUSION: While a definitive conclusion about the relevance of HRV and clinical depression measurement in ACS patients would be premature, the literature suggests that these measures may provide additional information in risk assessment. Potential avenues for further research are proposed.

Electrocardiographic abnormalities in the first year after heart transplantation.

STUDY AIM: Describe ECG abnormalities in the first year following transplant surgery. METHODS: Analysis of 12-lead ECGs from heart transplant subjects enrolled in an ongoing multicenter clinical trial. RESULTS: 585 ECGs from 98 subjects showed few with abnormal cardiac rhythm (99% of ECGs were sinus rhythm/tachycardia). A majority of subjects (69%) had either right intraventricular conduction delay (56%) or right bundle branch block (13%). A second prevalent ECG abnormality was atrial enlargement (64% of subjects) that was more commonly left atrial (55%) than right (30%). CONCLUSIONS: Right intraventricular conduction delay or right bundle branch block is prevalent in heart transplant recipients in the first year following transplant surgery. Whether this abnormality is related to acute allograph rejection or endomyocardial biopsy procedures is the subject of the ongoing clinical trial. Atrial enlargement ECG criteria (especially, left atrial) are also common and are likely due to transplant surgery with subsequent atrial remodeling.

Hyperglycemia is associated with corrected QT prolongation and mortality in acutely ill patients.

BACKGROUND: The QT interval on an electrocardiogram represents ventricular repolarization time. Increased length of this interval, known as corrected QT (QTc) prolongation, can be a precursor to torsade de pointes, a potentially life-threatening ventricular dysrhythmia. An association exists between blood glucose and QTc interval in ambulatory populations. Because both hyperglycemia and QTc prolongation are common in critically ill patients, we sought to examine the relationship between blood glucose, QTc interval prolongation, and all-cause mortality in critically ill patients. METHODS: We studied adult patients admitted to cardiac monitoring units. Blood glucose and other clinical variables were abstracted from the medical record. Corrected QT measurements were automatically derived from continuous bedside cardiac monitoring systems. RESULTS: Twenty-five percent (233/940) of the patients had QTc prolongation, and 53% had elevated blood glucose (>140 mg/dL) during hospitalization. Adjusted odds for QTc prolongation were 2.1 (95% confidence interval, 1.5-3.1) for moderately elevated blood glucose (140-180 mg/dL) and 3.7 (95% confidence interval, 2.5-5.4) for severely elevated blood glucose (>180 mg/dL). Mortality rate was highest (16%) in patients experiencing both severely elevated blood glucose (>180 mg/dL) and QTc interval prolongation. CONCLUSIONS: Hyperglycemia is linked with QTc prolongation, and both are associated with increased odds of mortality in critically ill patients. Further studies are needed to extrapolate the relationship between glucose and ventricular repolarization, as well as appropriate glucose control parameters and QTc interval monitoring in critical care units.