Expert-Identified Practices for Achieving Measurable Performance Improvements With Lean Implementation.

BACKGROUND AND OBJECTIVES: Despite the rapid spread of Lean management in health care, few organizations have achieved measurable overall performance improvements with Lean. What differentiates these organizations from those that struggle with realizing the potential benefits of Lean management is unclear. In this qualitative study we explore measuring the impact of Lean and the recommended practices for achieving measurable performance improvements with Lean in health care organizations. METHODS: Informed by preliminary quantitative results from analyses of high- and low-performing Lean hospitals, we conducted 17 semi-structured interviews with Lean health care experts on the Lean principles and practices associated with better performance. We conducted qualitative content analyses of the interview transcripts based on grounded theory and linking to core principles and practices of the Lean management system. RESULTS: The qualitative data revealed 3 categories of metrics for measuring the impact of Lean: currently used institutional measures, measures tailored to Lean initiatives, and population-level measures. Leadership engagement/commitment and clear organizational focus/prioritization/alignment had the highest weighted averages of success factors. The lack of these 2 factors had the highest weighted averages of biggest barriers for achieving measurable performance improvements with Lean implementation. CONCLUSIONS: Leadership engagement and organizational focus can facilitate achieving the organization's performance improvement goals, whereas their absence can considerably hinder performance improvement efforts. Many different approaches have been used to quantify the impact of Lean, but currently used institutional performance measures are preferred by the majority of Lean experts.

Validation of the Lean Healthcare Implementation Self-Assessment Instrument (LHISI) in the finnish healthcare context.

BACKGROUND: Lean management is growing in popularity in the healthcare sector worldwide, yet healthcare organizations are struggling with assessing the maturity of their Lean implementation and monitoring its change over time. Most existing methods for such assessments are time consuming, require site visits by external consultants, and lack frontline involvement. The original Lean Healthcare Implementation Self-Assessment Instrument (LHISI) was developed by the Center for Lean Engagement and Research (CLEAR), University of California, Berkeley as a Lean principles-based survey instrument that avoids the above problems. We validated the original LHISI in the context of Finnish healthcare. METHODS: The original HISI survey was sent over a secure organizational email system to the over 26,000 employees of the Hospital District of Helsinki and Uusimaa in March 2020. The data were randomly split with one part used to carry out an exploratory factor analysis (EFA), and the other for testing the resulting model using confirmatory factor analysis (CFA). RESULTS: A total of 6073 employees responded to the LHISI survey, for an overall response rate of 23%. The results indicated that the 43 items used in the original LHISI can be reduced to 25 items, and these items measure a five-dimensional model of the progress of Lean implementation: leadership, commitment, standard work, communication, and daily management system. In comparison with a single-factor model, the fit measures for the 5-factor model were better: smaller X2, larger comparative fit index (CFI), smaller root mean square error of approximation (RMSEA), and smaller standardized root mean square residual (SRMR). CONCLUSIONS: The 25 item LHISI is valid and feasible to use in the context of Finnish healthcare. The LHISI allows the organization to self-monitor the progress of its Lean implementation and provides the leadership with actionable knowledge to guide the path towards Lean maturity across the organization. Our findings encourage further studies on the adoption and validation of the LHISI in healthcare organizations worldwide.

The cross-national applicability of lean implementation measures and hospital performance measures: a case study of Finland and the USA.

BACKGROUND: Health-care organizations around the world are striving to achieve transformational performance improvement, often through adopting process improvement methodologies such as lean management. Indeed, lean management has been implemented in hospitals in many countries. But despite a shared methodology and the potential benefit of benchmarking lean implementation and its effects on hospital performance, cross-national lean benchmarking is rare. Health-care organizations in different countries operate in very different contexts, including different health-care system models, and these differences may be perceived as limiting the ability of improvers to benchmark lean implementation and related organizational performance. However, no empirical research is available on the international relevance and applicability of lean implementation and hospital performance measures. To begin understanding the opportunities and limitations related to cross-national benchmarking of lean in hospitals, we conducted a cross-national case study of the relevance and applicability of measures of lean implementation in hospitals and hospital performance. METHODS: We report an exploratory case study of the relevance of lean implementation measures and the applicability of hospital performance measures using quantitative comparisons of data from Hospital District of Helsinki and Uusimaa (HUS) Helsinki University Hospital in Finland and a sample of 75 large academic hospitals in the USA. RESULTS: The relevance of lean-related measures was high across the two countries: almost 90% of the items developed for a US survey were relevant and available from HUS. A majority of the US-based measures for financial performance (66.7%), service provision/utilization (100.0%) and service provision/care processes (60.0%) were available from HUS. Differences in patient satisfaction measures prevented comparisons between HUS and the USA. Of 18 clinical outcome measures, only four (22%) were not comparable. Clinical outcome measures were less affected by the differences in health-care system models than measures related to service provision and financial performance. CONCLUSIONS: Lean implementation measures are highly relevant in health-care organizations operating in the USA and Finland, as is the applicability of a variety of performance improvement measures. Cross-national benchmarking in lean healthcare is feasible, but a careful assessment of contextual factors, including the health-care system model, and their impact on the applicability and relevance of chosen benchmarking measures is necessary. The differences between the US and Finnish health-care system models is most clearly reflected in financial performance measures and care process measures.

Benchmarking outcomes on multiple contextual levels in lean healthcare: a systematic review, development of a conceptual framework, and a research agenda.

BACKGROUND: Reliable benchmarking in Lean healthcare requires widely relevant and applicable domains for outcome metrics and careful attention to contextual levels. These levels have been poorly defined and no framework to facilitate performance benchmarking exists. METHODS: We systematically searched the Pubmed, Scopus, and Web of Science databases to identify original articles reporting benchmarking on different contextual levels in Lean healthcare and critically appraised the articles. Scarcity and heterogeneity of articles prevented quantitative meta-analyses. We developed a new, widely applicable conceptual framework for benchmarking drawing on the principles of ten commonly used healthcare quality frameworks and four value statements, and suggest an agenda for future research on benchmarking in Lean healthcare. RESULTS: We identified 22 articles on benchmarking in Lean healthcare on 4 contextual levels: intra-organizational (6 articles), regional (4), national (10), and international (2). We further categorized the articles by the domains in the proposed conceptual framework: patients (6), employed and affiliated staff (2), costs (2), and service provision (16). After critical appraisal, only one fifth of the articles were categorized as high quality. CONCLUSIONS: When making evidence-informed decisions based on current scarce literature on benchmarking in healthcare, leaders and managers should carefully consider the influence of context. The proposed conceptual framework may facilitate performance benchmarking and spreading best practices in Lean healthcare. Future research on benchmarking in Lean healthcare should include international benchmarking, defining essential factors influencing Lean initiatives on different levels of context; patient-centered benchmarking; and system-level benchmarking with a balanced set of outcomes and quality measures.

A pilot study of parents' experiences of reflexology treatment for infants with colic in Finland.

BACKGROUND: Many infants under 4 months suffer from infantile colic. Infants with colic cry a lot, appear to be in pain, and it is difficult to sooth them. Colic is a painful condition for the infant and very stressful to parents. Parents in Finland get advice to try reflexology treatment for their infant, but there are no studies in Finland to support this advice. AIM: The aim of the pilot study was to treat infants with reflexology and find out parents' experiences of the effects of the treatment on colic symptoms and parental stress. METHOD: A total of 33 parents of 35 infants diagnosed with colic participated to the pilot study. Three certified reflexologists with health care education background and extensive experience in infant reflexology were trained to give the reflexology treatment in a standardised manner. They treated each infant 3-4 times. The whole body reflexology treatment session consisted of gentle pressure treatment of soles and feet, hands, head, face, ears, back, neck and whole stomach area. One treatment session lasted about 20-30 minutes, and treatments were delivered within 8-12 days. The data were collected from the parents with semi-structured questionnaires. RESULTS: The series of the treatments helped reduce the suffering of all the babies with infant colic. The colic symptoms disappeared on 43% of infants and decreased on the remaining 57%. The parents reported having pleasant experiences with the treatment, regardless whether the colic symptoms disappeared or continued. Parents stated that the treatment reduced the most typical colic symptoms; infants' body tension, colic crying and restless movements, poor sleep quality and irregular bowel movements. CONCLUSIONS: Reflexology treatment seems to be a safe and effective way to treat infants with colic when conducted by a health care professional with reflexology training and experience.

Anticoagulation therapy among patients presenting to the emergency department with symptomatic atrial fibrillation - the FinFib2 study.

OBJECTIVES: Atrial fibrillation (AF) causes numerous visits to emergency departments (EDs). We evaluated the thromboembolic and bleeding risk profile and use of oral anticoagulation (OAC) therapy among patients presenting with symptomatic AF to ED. METHODS: Within a 2-week period, all patients whose primary reason for the ED visit was AF were enrolled into this prospective study in 35 EDs around Finland. The risk of thromboembolic and bleeding events was assessed by the CHA2DS2VASc and the HAS-BLED score, respectively. Thereafter, we evaluated whether OAC was used according to the contemporary management guidelines. RESULTS: The study population included 1013 patients (mean age 70±13 years, 52.4% men) with newly or previously diagnosed symptomatic AF. The mean CHA2DS2VASc and HAS-BLED score was 3.1±2.1 and 1.9±1.2, respectively. At admission, 76.3% of the patients with previously diagnosed AF and CHA2DS2VASc score of at least 2 were using OAC (warfarin 92.3%). However, the international normalized ratio was not at the therapeutic level in 41.9% of them. At discharge, 84.1% of the high-risk patients (85.5% of previously diagnosed and 79.6% of newly diagnosed) and 57.0 and 37.0% of the moderate-risk and low-risk patients were on OAC, respectively. Of the high-risk patients, 5.4% were treated with aspirin. CONCLUSION: These data showed that OAC was prescribed frequently to patients with symptomatic AF and risk factors for stroke. However, in patients using warfarin, international normalized ratio was not at the therapeutic level in a large proportion of the patients with previously diagnosed AF.

Comparison of QT peak and QT end interval responses to autonomic adaptation in asymptomatic LQT1 mutation carriers.

BACKGROUND: LQT1 subtype of long QT syndrome is characterized by defective I(Ks) , which is intrinsically stronger in the epicardium than in the midmyocardial region. Electrocardiographic QT peak and QT end intervals may reflect complete repolarization of epicardium and midmyocardial region of the ventricular wall, respectively. Repolarization abnormalities in LQT1 carriers may therefore be more easily detected in the QT peak intervals. METHODS: Asymptomatic KCNQ1 mutation carriers (LQT1, n=9) and unaffected healthy controls (n=8) were studied during Valsalva manoeuvre, mental stress, handgrip and supine exercise. Global QT peak and QT end intervals derived from 25 simultaneous electrocardiographic leads were measured beat to beat with an automated method. RESULTS: In unaffected subjects, the percentage shortening of QT peak was greater than that of QT end during mental stress and during the recovery phases of Valsalva and supine exercise. In LQT1 carriers, the percentage shortening of the intervals was similar. At the beginning of Valsalva strain under abrupt endogenous sympathetic activation, QT peak shortened in LQT1 but not in control patients yielding increased electrocardiographic transmural dispersion of repolarization in LQT1. CONCLUSIONS: In asymptomatic KCNQ1 mutation carriers, repolarization abnormalities are more evident in the QT peak than in the QT end interval during adrenergic adaptation, possibly related to transmural differences in the degree of I(Ks) block.

Fragmented QRS in prediction of cardiac deaths and heart failure hospitalizations after myocardial infarction.

BACKGROUND: Increased QRS fragmentation in visual inspection of 12-lead ECG has shown association with cardiac events in postmyocardial infarction (MI) patients. We investigated user-independent computerized intra-QRS fragmentation analysis in prediction of cardiac deaths and heart failure (HF) hospitalizations after MI. METHODS: Patients (n = 158) with recent MI and reduced left ventricular ejection fraction (LVEF) were studied. A 120-lead body surface potential mapping was performed at hospital discharge. Intra-QRS fragmentation was computed as the number of extrema (fragmentation index FI) in QRS. QRS duration (QRSd) was computed for comparison. RESULTS: During a mean follow-up of 50 months 15 patients suffered cardiac death and 23 were hospitalized for HF. Using the mean + 1 SD as cut-point both parameters were univariate predictors of both end-points. In multivariate analysis including age, gender, LVEF, previous MI, bundle branch block, atrial fibrillation, and diabetes FI was an independent predictor for cardiac deaths (HR 8.7, CI 3.0-25.6) and HF hospitalizations (HR 3.8, CI 1.6-9.3) whereas QRSd only predicted HF hospitalizations (HR 4.6, CI 2.0-10.7). In comparison to QRSd, FI showed better positive (PPA) and equal negative (NPA) predictive accuracy for both end-points, and PPA was further improved when combined to LVEF < 40%. Limiting fragmentation analysis to 12-lead ECG or a randomly selected 8-lead set instead of all 120 leads resulted in an almost similar prediction. CONCLUSIONS: Increased QRS fragmentation in post-MI patients predicts cardiac deaths and HF progression. A computer-based fragmentation analysis is a stronger predictor than QRSd.

Interatrial right-to-left conduction in patients with paroxysmal atrial fibrillation.

PURPOSE: We wanted to illustrate the right-to-left impulse propagation routes during sinus in patients with paroxysmal atrial fibrillation (PAF), as alterations in conduction patterns have been linked to the pathogenesis of PAF, and as no large patient materials have been published. METHODS: Patients underwent 3-D electroanatomical contact mapping prior to catheter ablation. The site of the earliest left atrial (LA) activation was determined. RESULTS: Three different interatrial routes were identified, either as solitary pathways (36/50 patients, 72%) or in their combinations (14/50). Bachmann's bundle (BB) was involved in the majority of the cases with solitary routes (25/36). More seldom, impulse propagation occurred near the oval fossa (FO) (7/36) or the coronary sinus ostium (4/36). In patients with combined routes, both the BB (10/14) and FO routes (11/14) were included in most cases. CONCLUSIONS: In PAF patients, LA can be activated during sinus rhythm through three distinct connections, either encompassing a single route or via any combination of these connections. In one third, the earliest LA activation occurs outside BB. The knowledge of the propagation patterns may give insight into the pathophysiology of PAF and into refining ablation therapy.

Complex T-wave morphology in body surface potential mapping in prediction of arrhythmic events in patients with acute myocardial infarction and cardiac dysfunction.

AIMS: Heterogeneous ventricular repolarization is associated with sudden cardiac death after myocardial infarction (MI). This prospective study investigated repolarization disparity with parameters based on T-wave morphology in body surface potential mapping (BSPM) in the assessment of arrhythmia risk in patients with a recent MI and cardiac dysfunction. METHODS AND RESULTS: Patients (n = 158) had 120-lead BSPM and 12-lead electrocardiogram (ECG) registered soon after acute MI. Principal component analysis (PCA) of the T-wave and T-wave vector loop descriptors were applied to compute parameters describing T-wave morphology and its variation. The study endpoints were arrhythmic events and all-cause mortality. During a mean follow-up of 50 months, 30 patients (19%) died and 16 (10%) had an arrhythmic event. Most of the parameters differed significantly between patients with and without arrhythmic events. In univariate analysis, T-wave vector loop length (TLL) and PCA parameter PCA(3) in BSPM and TLL in ECG were significant predictors of arrhythmic events. In multivariate analysis including several clinical variables, these parameters also showed an independent prediction, with parameters in BSPM performing somewhat better. None of the parameters predicted all-cause mortality. CONCLUSION: Complex T-wave morphology in BSPM is a marker of arrhythmia propensity in patients with a recent MI and cardiac dysfunction.

Arrhythmias and heart rate variability during and after therapeutic hypothermia for cardiac arrest.

OBJECTIVE: To evaluate the effects of therapeutic hypothermia (HT) of 33 degrees C after cardiac arrest (CA) on cardiac arrhythmias, heart rate variability (HRV), and their prognostic value. DESIGN: Prospective, comparative substudy of a randomized controlled trial of mild HT after out-of-hospital CA, the European Hypothermia After Cardiac Arrest study. SETTING: Intensive care unit of a tertiary referral hospital (Helsinki University Hospital). PATIENTS: Seventy consecutive adult patients resuscitated from out-of-hospital ventricular fibrillation were randomly assigned either to therapeutic HT of 33 degrees C or normothermia. INTERVENTIONS: Patients randomized to HT were cooled with an external cooling device for 24 hours and then allowed to rewarm slowly during 12 hours. In the normothermia group, the core temperature was kept <38 degrees C by antipyretics and physical means. All patients received standard intensive care for at least 2 days. MEASUREMENTS AND MAIN RESULTS: Twenty-four hour ambulatory electrocardiography recordings were performed at 0-24 hours, at 24-48 hours, and at 14 days. The clinical outcome was assessed at 6 months after CA. The occurrence of premature ventricular beats was increased in the HT-treated group during the first two recordings, with no difference in the number of ventricular tachycardia or ventricular fibrillation episodes. All HRV values were significantly higher during the HT (p < 0.01), but no differences were observed 2 weeks later. In multivariate analysis, only shorter delay to restoration of spontaneous circulation (p = 0.009) and the sd of individual normal-to-normal intervals >100 msec of the 24-48-hour recording in the HT group (p = 0.018) predicted good outcome. CONCLUSIONS: The use of therapeutic HT of 33 degrees C for 24 hours after CA was not associated with an increase in clinically significant arrhythmias. Preserved 24 to 48-hour HRV may be a predictor of favorable outcome in patients with CA treated with HT.

High-resolution signal-averaged analysis of atrial electromagnetic characteristics in patients with paroxysmal lone atrial fibrillation.

BACKGROUND: Abnormalities in the electromagnetic signal of the atria during sinus rhythm could serve as markers of triggering foci or substrate for atrial fibrillation (AF). We examined atrial electrophysiologic properties noninvasively by using magnetocardiographic mapping (MCG) in patients with paroxysmal lone AF to find whether any difference exists between those who have frequent triggers of AF and who don't. METHODS: MCG was recorded over anterior chest during sinus rhythm in 80 patients with paroxysmal lone AF (44 +/- 12 years, 61 males) and 80 matched controls. Atrial wave duration (Pd) and root mean square amplitudes of the last 40 ms (RMS40) of the averaged filtered atrial complex were determined automatically. Patients expressing atrial arrhythmias triggering AF episodes were classified as focal AF. RESULTS: The Pd was 109 ms in patients and 104 ms in controls (P = 0.007). In focal AF (72%) the Pd was slightly prolonged and its proportion of the PR interval was larger, but RMS40 was normal compared to controls. In other patients, the Pd was close to controls, but the RMS40 was reduced (59 +/- 17 vs74 +/- 36 fT, P = 0.006). Pd and atrial RMS amplitudes were unrelated to duration of AF history or frequency of recurrences. CONCLUSION: Clinical subclasses of lone AF seem to possess distinct signal profiles of atrial depolarization. Differences in electrophysiological properties between these subclasses may reflect pathogenetic variation and could have implications on diagnostics and therapy.

Electrocardiographic interventricular dispersion of repolarization during autonomic adaptation in LQT1 subtype of long QT syndrome.

OBJECTIVES: In LQT1 subtype of inherited long QT syndrome, repolarization abnormalities originating from defective I(Ks) render patients vulnerable to ventricular arrhythmia during sudden sympathetic activation. Experimental studies show lower I(Ks) density and longer action potential duration in left (LV) than in right (RV) ventricle. We studied interventricular dispersion of repolarization in patients with I(Ks) defect during autonomic tests. DESIGN: We measured interventricular (difference of QT intervals between LV and RV type leads) and transmural electrocardiographic dispersion of repolarization from 25-lead electrocardiograms in nine asymptomatic KCNQ1 mutation carriers (LQT1) and eight controls during rest, Valsalva maneuver, mental stress, sustained handgrip and supine exercise. RESULTS: LQT1 carriers showed increased interventricular dispersion of repolarization (13+/-9 ms vs. 4+/-4 ms, p=0.03) during all tests. Valsalva strain increased the difference between the study groups. In LQT1 carriers, interventricular dispersion of repolarization correlated weakly with electrocardiographic transmural dispersion of repolarization. CONCLUSIONS: Asymptomatic KCNQ1 mutation carriers exhibit increased and by abrupt sympathetic activation augmented interventricular difference in electrocardiographic repolarization times. Interventricular and transmural repolarization dispersion behave similarly in patients with I(Ks) defect.

Case of the month by the EHRA Education committee: exercise-related arrhythmias.

This case describes two nephews with exercise-related arrhythmias.

Case of polymorphic ventricular tachycardia after stroke necessitating defibrillation.

This case describes the occurrence of a tachycardia occurring early after a subarachnoid haemorrhage.

Localization of prior myocardial infarction by repolarization variables.

BACKGROUND: To find quantitative, automatically applicable electrocardiographic (ECG) variables for detecting prior myocardial infarction (MI) in different myocardial regions. METHODS: Observational study. Body surface potential mapping (BSPM) was recorded at rest, and automatically analyzed with regard to ECG parameters, blinded to the clinical characteristics of the study subjects, 144 patients with prior MI and 75 healthy controls. MI location was determined by cine angiography or echocardiography as anterior (66 patients), inferoposterior (89 patients), and lateral (15 patients). Patients' 12-lead ECG was interpreted according to Minnesota code (Q-wave MI in 97 patients). The QRSSTT, QRS, and STT integrals, and the T-apex amplitude in detecting prior anterior and inferoposterior MI were analyzed. RESULTS: The T-apex amplitude, QRSSTT integral, and STT integral were functional in detecting MI in all tested locations on a single-lead basis, with areas under receiver operating characteristic curves (AUC) of over 90% (p<0.001) in optimal sites. In the best leads AUC for the QRSSTT integral in anterior MI was 93% (CI 87-99%) and for the inferoposterior MI 92% (CI 88-97%). These repolarization variables outperformed the Minnesota code in all tested MI locations. They were also able to distinguish between anterior and inferoposterior MI with an AUC of >85% (p<0.001). CONCLUSIONS: Quantitative, automatically applicable single-lead repolarization variables detect prior MI irrespective of its location. They may simplify the screening for and localization of old infarctions as compared to the conventional ECG methods.

Single-lead electrocardiographic variables in the detection of prior myocardial infarction with respect to Q-wave status and infarct age.

OBJECTIVES: Conventionally, the detection of prior myocardial infarction (MI) is based on QRS abnormalities, which may ignore non-Q-wave MI (NQMI). We aimed at finding automatically applicable quantitative ECG variables for diagnosing prior MI. METHODS: Body surface potential mapping (BSPM) was registered and automatically analyzed in 144 patients with prior MI and in 75 healthy controls. The MI was defined according to its age as recent or old, and Q-wave status as Q-wave MI (QMI) or NQMI. RESULTS: The QRSSTT integral, the STT integral and the T-wave apex amplitude applied in single, selected leads were found to be the optimal parameters in the detection of prior MI. The areas under the receiver-operating characteristic curves (AUC) were 89% for each, and detection was equal in old and recent MI (AUCs from 87 to 90%), and in QMI and NQMI (AUCs from 88 to 90%). CONCLUSIONS: The quantitative, automatically applicable single-lead variables comprising ventricular repolarization was effective in detecting prior MI, irrespective of the time elapsed from MI or the Q-wave status. These variables could be suitable for population studies and health screening purposes and are applicable to automatic ECG diagnostics of prior MI.

Ventricular repolarization and heart rate responses during cardiovascular autonomic function testing in LQT1 subtype of long QT syndrome.

BACKGROUND: In the most prevalent LQT1 form of inherited long QT syndrome symptoms often occur during abrupt physical or emotional stress. Sympathetic stimulation aggravates repolarization abnormalities in experimental LQT1 models. We hypothesized that autonomic function tests might reveal the abnormal repolarization in asymptomatic LQT1 patients. METHODS: We measured heart rates (HRs) and QT intervals in nine asymptomatic carriers of a C-terminal KCNQ1 mutation and 8 unaffected healthy subjects using an approach of global QT values derived from 28 simultaneous electrocardiographic leads on beat-to-beat base during Valsalva maneuver, mental stress, sustained handgrip, and light supine exercise. RESULTS: LQT1 patients exhibited impaired shortening of both QTpeak and QTend intervals during autonomic interventions but exaggerated lengthening of the intervals--a QT overshoot--during the recovery phases. The number of tests with a QT overshoot was 2.4 +/- 1.7 in LQT1 patients and 0.8 +/- 0.7 in unaffected subjects (P = 0.02). Valsalva strain prolonged T wave peak to T wave end interval (TPE) in LQT1 but not in unaffected patients. LQT1 patients showed diminished HR acceleration in response to adrenergic challenge whereas HR responses to vagal stimuli were similar in both groups. CONCLUSIONS: Standard cardiovascular autonomic provocations induce a QT interval overshoot during recovery in asymptomatic KCNQ1 mutation carriers. Valsalva maneuver causes an exaggerated fluctuation of QT and TPE intervals partly explaining the occurrence of cardiac events during abrupt bursts of autonomic activity in LQT1 patients.

QRS duration in high-resolution methods and standard ECG in risk assessment after first and recurrent myocardial infarctions.

BACKGROUND: Prolonged QRS duration (QRSd) is associated with increased mortality after myocardial infarction (MI). Only little data exist about its predictive ability and relationships to clinical variables in the present era of active treatment of myocardial ischemia and cardiac dysfunction. We investigated whether QRSd in high-resolution methods and standard ECG predict arrhythmic events and cardiac death in post-infarction patients with cardiac dysfunction and how it relates to clinical variables, with a special emphasis on history of previous MI. METHODS AND RESULTS: Patients (n = 158) with acute MI and cardiac dysfunction had magnetocardiography (MCG), signal-averaged ECG (SAECG), and ECG registered at discharge. Patients with a previous MI had significantly longer QRSd although their left ventricular function was almost similarly impaired. During the mean follow-up of 50 +/- 15 (range 1-72) months, 32 patients died and 17 (53%) of the deaths were classified as cardiac. Eighteen patients had an arrhythmic event. QRSd >121 ms in MCG and >114 ms in SAECG were significant predictors of arrhythmic events and cardiac death, whereas QRSd in ECG predicted only cardiac death. In multivariate analysis, QRSd in MCG (hazard ratio (HR) = 3.6, P = 0.007) and SAECG (HR = 4.6, P = 0.016) predicted only arrhythmic events, whereas QRSd in ECG was an independent predictor of cardiac death. CONCLUSIONS: Prolonged QRSd in MCG and SAECG are powerful indicators of the arrhythmia substrate in post-infarction patients with cardiac dysfunction, whereas prolonged QRSd in standard ECG associates with increased risk of cardiac death.

Magnetocardiographic assessment of healed myocardial infarction.

BACKGROUND: We evaluated the capability of multichannel magnetocardiography (MCG) to detect healed myocardial infarction (MI). METHODS: Multichannel MCG over frontal chest was recorded at rest in 21 patients with healed MI, detected by cine- and contrast-enhanced magnetic resonance imaging, and in 26 healthy controls. Of the 21 MI patients, 11 had non-Q wave and 10 Q wave MIs. QRS, ST-segment, T wave and ST-T wave integrals, ST-segment and T wave amplitudes, and QRS and ST-T wave magnetic field map orientations were measured. RESULTS: The MCG repolarization indexes, such as ST segment and ST-T wave integrals, separated the MI group from the controls (ST-T wave integral -1.4 +/- 5.3 vs 1.5 +/- 4.7 pTs, P = 0.034). The abnormalities were more distinct in the Q wave-MI than in the non-Q wave MI subgroup. In the latter, however, a trend similar to the Q wave MI group was found. The relation of QRS area to ST segment and T wave integral improved the detection of healed MIs compared to the ST-T wave indexes alone (QRS-ST-T discordance 14 +/- 10 vs 5.0 +/- 7.1 pTs, P = 0.003). When comparing the MI group to the controls, the orientation of the magnetic field maps differed in the ST-T wave maps (163 +/- 119 degrees vs 58 +/- 17 degrees, P < 0.001) but not in the QRS maps (111 +/- 95 degrees vs 106 +/-93 degrees, P = 0.646). CONCLUSIONS: The MCG repolarization variables can detect healed MI. These ST-T wave abnormalities are more pronounced in patients with Q wave MI than in patients with non-Q wave MIs. Relating the signals of depolarization and repolarization phases improves the detection of healed MI. Repolarization abnormalities are common in healed MI and thus should not always be interpreted as present ongoing ischemia.