Hybrid Artificial Intelligence Solution Combining Convolutional Neural Network and Analytical Approach Showed Higher Accuracy in A-lines Detection on Lung Ultrasound in Thoracic Surgery Patients Compared with Radiology Resident.

OBJECTIVES: Lung ultrasound reduces the number of chest X-rays after thoracic surgery and thus the radiation. COVID-19 pandemic has accelerated research in lung ultrasound artifacts detection using artificial intelligence. This study evaluates the accuracy of artificial intelligence in A-lines detection in thoracic surgery patients using a novel hybrid solution that combines convolutional neural networks and analytical approach and compares it with a radiology resident and radiology experts' results. DESIGN: Prospective observational study. MATERIAL AND METHODS: Single-center study evaluates the accuracy of artificial intelligence and a radiology resident in A-line detection on lung ultrasound footages compared with the consensual opinion of two expert radiologists as the reference. After resident's first reading, the artificial intelligence results were presented to the resident and he was asked to revise the results based on artificial intelligence. RESULTS: 82 consecutive patients underwent 82 ultrasound examinations. 328 ultrasound recordings were evaluated. Accuracy, sensitivity, specificity, positive and negative predictive values of artificial inelligence in A-line detection were 0.866, 0.928, 0.834, 0.741 and 0.958 respectively. The resident's values were 0.558, 0.973, 0.346, 0.432 and 0.962 respectively. The resident's values after correction based on artificial intelligence results were 0.854, 0.991, 0.783, 0.701 and 0.994 respectively. CONCLUSION: Artificial intelligence showed high accuracy in A-line detection in thoracic surgery patients and was more accurate compared to a resident. Artificial intelligence could play important role in lung ultrasound artifact detection in thoracic surgery patients and in residents' education.

Lung Ultrasound Reduces Chest X-rays in Postoperative Care after Thoracic Surgery: Is There a Role for Artificial Intelligence?-Systematic Review.

BACKGROUND: Chest X-ray (CXR) remains the standard imaging modality in postoperative care after non-cardiac thoracic surgery. Lung ultrasound (LUS) showed promising results in CXR reduction. The aim of this review was to identify areas where the evaluation of LUS videos by artificial intelligence could improve the implementation of LUS in thoracic surgery. METHODS: A literature review of the replacement of the CXR by LUS after thoracic surgery and the evaluation of LUS videos by artificial intelligence after thoracic surgery was conducted in Medline. RESULTS: Here, eight out of 10 reviewed studies evaluating LUS in CXR reduction showed that LUS can reduce CXR without a negative impact on patient outcome after thoracic surgery. No studies on the evaluation of LUS signs by artificial intelligence after thoracic surgery were found. CONCLUSION: LUS can reduce CXR after thoracic surgery. We presume that artificial intelligence could help increase the LUS accuracy, objectify the LUS findings, shorten the learning curve, and decrease the number of inconclusive results. To confirm this assumption, clinical trials are necessary. This research is funded by the Slovak Research and Development Agency, grant number APVV 20-0232.

A Rare Case Diagnosed by Videothoracoscopic Lung Biopsy: Diffuse Pulmonary Meningotheliomatosis.

Diffuse pulmonary meningotheliomatosis (DPM) is reported as a diffuse parenchymal lung disease characterized by disseminating small asymptomatic nodules. These lesions are often detected incidentally as microscopic findings in lung specimens or autopsies examined by a pathologist. We report a case of a 60-year-old male asymptomatic patient presenting with multiple bilateral pulmonary nodules on high-resolution computed tomography and diagnosed by videothoracoscopic surgery. Differential diagnosis of patients presenting with diffuse indeterminate nodules is very important. Definitive diagnosis of DPM requires histopathology and most often videothoracoscopic lung biopsy.

Chest Ultrasound Can Reduce the Use of Roentgenograms in Postoperative Care After Thoracic Surgery.

BACKGROUND: Roentgenography remains the standard imaging modality after thoracic surgery. Trials from intensive medicine proved a high accuracy of ultrasound examination in the diagnosis of various conditions. The assumption was that ultrasound examination could reduce the number of roentgenograms after thoracic surgery. METHODS: This prospective study compared ultrasound examinations performed by thoracic surgeons with roentgenograms in the diagnosis of pneumothorax and pleural effusion after noncardiac thoracic surgery. Patients received 2 ultrasound scans, the first on the day of surgery and the second before chest tube removal. RESULTS: A total of 297 patients underwent 545 examinations; 336 ultrasound scans (61.6%) showed neither pneumothorax nor pleural effusion. Pneumothorax was detected on 69 roentgenograms and 51 ultrasound scans. Both modalities showed positive results in 32 cases and negative results in 395 cases (Cohen's κ, 53.4%). Ultrasound missed 37 clinically irrelevant pneumothoraces. Roentgenograms missed 19 pneumothoraces; 15 of them were clinically irrelevant. Sensitivity and specificity were 59.4% and 95.9% in the first examination and 50.0% and 94.8% in the second examination, respectively. Pleural effusion was detected on 169 roentgenograms and 117 ultrasound scans. Both modalities showed positive results in 88 cases and negative results in 336 cases (Cohen's κ, 49.6%). Ultrasound scans missed 81 pleural effusions; except for 5 cases, the clinical decisions would not have changed. Roentgenograms missed 29 clinically irrelevant pleural effusions. Sensitivity and specificity were 44.4% and 92.6% in the first examination and 60.9% and 91.3% in the second examination, respectively. CONCLUSIONS: Given high specificities, a large share of results without pneumothorax and pleural effusion, and mismatch analysis, we could reduce the number of roentgenograms by 61.6% by using ultrasound as a primary imaging modality.

Cardiovascular Mortality Can Be Predicted by Heart Rate Turbulence in Hemodialysis Patients.

BACKGROUND: Excess mortality in hemodialysis patients is mostly of cardiovascular origin. We examined the association of heart rate turbulence (HRT), a marker of baroreflex sensitivity, with cardiovascular mortality in hemodialysis patients. METHODS: A population of 290 prevalent hemodialysis patients was followed up for a median of 3 years. HRT categories 0 (both turbulence onset [TO] and slope [TS] normal), 1 (TO or TS abnormal), and 2 (both TO and TS abnormal) were obtained from 24 h Holter recordings. The primary end-point was cardiovascular mortality. Associations of HRT categories with the endpoints were analyzed by multivariable Cox regression models including HRT, age, albumin, and the improved Charlson Comorbidity Index for hemodialysis patients. Multivariable linear regression analysis identified factors associated with TO and TS. RESULTS: During the follow-up period, 20 patients died from cardiovascular causes. In patients with HRT categories 0, 1 and 2, cardiovascular mortality was 1, 10, and 22%, respectively. HRT category 2 showed the strongest independent association with cardiovascular mortality with a hazard ratio of 19.3 (95% confidence interval: 3.69-92.03; P < 0.001). Age, calcium phosphate product, and smoking status were associated with TO and TS. Diabetes mellitus and diastolic blood pressure were only associated with TS. CONCLUSION: Independent of known risk factors, HRT assessment allows identification of hemodialysis patients with low, intermediate, and high risk of cardiovascular mortality. Future prospective studies are needed to translate risk prediction into risk reduction in hemodialysis patients.

Prediction of mortality benefit based on periodic repolarisation dynamics in patients undergoing prophylactic implantation of a defibrillator: a prospective, controlled, multicentre cohort study.

BACKGROUND: A small proportion of patients undergoing primary prophylactic implantation of implantable cardioverter defibrillators (ICDs) experiences malignant arrhythmias. We postulated that periodic repolarisation dynamics, a novel marker of sympathetic-activity-associated repolarisation instability, could be used to identify electrically vulnerable patients who would benefit from prophylactic implantation of ICDs by way of a reduction in mortality. METHODS: We did a prespecified substudy of EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillators (EU-CERT-ICD), a prospective, investigator-initiated, non-randomised, controlled cohort study done at 44 centres in 15 EU countries. Patients aged 18 years or older with ischaemic or non-ischaemic cardiomyopathy and reduced left ventricular ejection fraction (≤35%) were eligible for inclusion if they met guideline-based criteria for primary prophylactic implantation of ICDs. Periodic repolarisation dynamics from 24-h Holter recordings were assessed blindly in patients the day before ICD implantation or on the day of study enrolment in patients who were conservatively managed. The primary endpoint was all-cause mortality. Propensity scoring and multivariable models were used to assess the interaction between periodic repolarisation dynamics and the treatment effect of ICDs on mortality. FINDINGS: Between May 12, 2014, and Sept 7, 2018, 1371 patients were enrolled in our study. 968 of these patients underwent ICD implantation, and 403 were treated conservatively. During follow-up (median 2·7 years [IQR 2·0-3·3] in the ICD group and 1·2 years [0·8-2·7] in the control group), 138 (14%) patients died in the ICD group and 64 (16%) patients died in the control group. We noted a 43% reduction in mortality in the ICD group compared with the control group (adjusted hazard ratio [HR] 0·57 [95% CI 0·41-0·79]; p=0·0008). Periodic repolarisation dynamics significantly predicted the treatment effect of ICDs on mortality (adjusted p=0·0307). The mortality benefits associated with ICD implantation were greater in patients with periodic repolarisation dynamics of 7·5 deg or higher (n=199; adjusted HR 0·25 [95% CI 0·13-0·47] for the ICD group vs the control group; p<0·0001) than in those with periodic repolarisation dynamics less than 7·5 deg (n=1166; adjusted HR 0·69 [95% CI 0·47-1·00]; p=0·0492; pinteraction=0·0056). The number needed to treat was 18·3 (95% CI 10·6-4895·3) in patients with periodic repolarisation dynamics less than 7·5 deg and 3·1 (2·6-4·8) in those with periodic repolarisation dynamics of 7·5 deg or higher. INTERPRETATION: Periodic repolarisation dynamics predict mortality reductions associated with prophylactic implantation of ICDs in contemporarily treated patients with ischaemic or non-ischaemic cardiomyopathy. Periodic repolarisation dynamics could help to guide treatment decisions about prophylactic ICD implantation. FUNDING: The European Community's 7th Framework Programme.

Bilateral cystic lesions of the chest wall: Presentation of scapulothoracic bursitis.

INTRODUCTION: Scapulothoracic articulation has several bursae which allow a sliding movement of the scapulothoracic joint. The two major anatomical bursae are the supraserratus bursa and infraserratus bursa. PRESENTATION OF CASE: It was a case of a 59 year-old female patient with a professional load and a clinical finding of bilateral subscapular resistances of the thorax. The finding of bilateral collections in the intermuscular spaces between external intercostal muscles and heads of serratus anterior muscle was verified by magnetic resonance. CONCLUSION: Due to progressively increasing bilateral findings an open surgical resection was implemented, with good result.

A multidisciplinary approach to the management of descending necrotizing mediastinitis - case series.

OBJECTIVES: Descending necrotizing mediastinitis (DNM) is a severe potentially fatal disease of the mediastinum which spreads downwards from oropharyngeal region. Mortality varies from 11 to 40%. There is agreement on the importance of early diagnosis, aggressive surgical treatment and the need for a multidisciplinary approach. DESIGN: Retrospective study of series of patient treated for DNM regarding multidisciplinary approach and surgical treatment. PATIENTS AND METHODS: Sixteen patients that were surgically treated for DNM from 2008 to 2017 at our hospital were consecutively enrolled in observational descriptive study. RESULTS: Twelve patients had disease localised above tracheal bifurcation level. Nine of them underwent transcervical drainage, three patients underwent more extensive treatment. Four patients with disease spread below the treacheal bifurcation level were treated with transcervical drainage in combination with posterolateral thoracotomy or videothoracoscopy. Three patients underwent videothoracoscopy - two of them as primary surgical treatment with need of one reoperation - contralateral videothoracoscopy. The third patient was initially treated with a transcervical approach and videothoracoscopy was indicated as a reoperation because of the progression of the disease. One patient died (mortality 6.25%). CONCLUSION: In management of descending necrotizing mediastinitis, early diagnosis, aggressive surgical treatment and use of broad-spectrum antibiotics and nowadays also multidisciplinary approach are crucial. Transcervical drainage combined with posterolateral thoracotomy or videothoracoscopy were used with good results.

Adiponectin, biomarkers of inflammation and changes in cardiac autonomic function: Whitehall II study.

BACKGROUND: Biomarkers of inflammation and adiponectin are associated with cardiovascular autonomic neuropathy (CAN) in cross-sectional studies, but prospective data are scarce. This study aimed to assess the associations of biomarkers of subclinical inflammation and adiponectin with subsequent changes in heart rate (HR) and heart rate variability (HRV) in non-diabetic and diabetic individuals. METHODS: Data are based on up to 25,050 person-examinations for 8469 study participants of the Whitehall II cohort study. Measures of CAN included HR and several HRV indices. Associations between baseline serum levels of high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-1 receptor antagonist (IL-1Ra) and adiponectin and 5-year changes in HR and six HRV indices were estimated using mixed-effects models adjusting for age, sex, ethnicity, body mass index (BMI), metabolic covariates and medication. A modifying effect of diabetes was tested. RESULTS: Higher levels of IL-1Ra were associated with higher increases in HR. Additional associations with measures of HRV were observed for hsCRP, IL-6 and IL-1Ra, but these associations were explained by BMI and other confounders. Associations between adiponectin, HR and HRV differed depending on diabetes status. Higher adiponectin levels were associated with more pronounced decreases in HR and increases in three measures of HRV reflecting both sympathetic and vagal activity, but these findings were limited to individuals with type 2 diabetes. CONCLUSIONS: Higher IL-1Ra levels appeared as novel risk marker for increases in HR. Higher adiponectin levels were associated with a more favourable development of cardiovascular autonomic function in individuals with type 2 diabetes independently of multiple confounders.

Sex differences in long-term mortality among acute myocardial infarction patients: Results from the ISAR-RISK and ART studies.

BACKGROUND: Mortality rates in females who survived acute myocardial infarction (AMI) exceed those in males. Differences between sexes in age, cardiovascular risk factors and revascularization therapy have been proposed as possible reasons. OBJECTIVE: To select sets of female and male patients comparable in respect of relevant risk factors in order to compare the sex-specific risk in a systematic manner. METHODS: Data of the ISAR-RISK and ART studies were investigated. Patients were enrolled between 1996 and 2005 and suffered from AMI within 4 weeks prior to enrolment. Patients of each sex were selected with 1:1 equivalent age, previous AMI history, sinus-rhythm presence, hypertension, diabetes mellitus, smoking status, left ventricular ejection fraction (LVEF), and revascularization therapy. Survival times were compared between sex groups in the whole study cohort and in the matched cohort. RESULTS: Of 3840 consecutive AMI survivors, 994 (25.9%) were females and 2846 (74.1%) were males. Females were older and suffered more frequently from hypertension and diabetes mellitus. In the whole cohort, females showed an increased mortality with a hazard ratio (HR) of 1.54 compared to males (p<0.0001). The matched cohort comprised 802 patients of each sex and revealed a trend towards poorer survival in females (HR for female sex 1.14; p = 0.359). However, significant mortality differences with a higher risk in matched females was observed during the first year after AMI (HR = 1.61; p = 0.045) but not during the subsequent years. CONCLUSION: Matched sub-groups of post-AMI patients showed a comparable long-term mortality. However, a female excess mortality remained during first year after AMI and cannot be explained by differences in age, cardiovascular risk factors, and modes of acute treatment. Other causal factors, including clinical as well as psychological and social aspects, need to be considered. Female post-AMI patients should be followed more actively particularly during the first year after AMI.

Automatic SVM classification of sudden cardiac death and pump failure death from autonomic and repolarization ECG markers.

BACKGROUND: Considering the rates of sudden cardiac death (SCD) and pump failure death (PFD) in chronic heart failure (CHF) patients and the cost-effectiveness of their preventing treatments, identification of CHF patients at risk is an important challenge. In this work, we studied the prognostic performance of the combination of an index potentially related to dispersion of repolarization restitution (Δα), an index quantifying T-wave alternans (IAA) and the slope of heart rate turbulence (TS) for classification of SCD and PFD. METHODS: Holter ECG recordings of 597 CHF patients with sinus rhythm enrolled in the MUSIC study were analyzed and Δα, IAA and TS were obtained. A strategy was implemented using support vector machines (SVM) to classify patients in three groups: SCD victims, PFD victims and other patients (the latter including survivors and victims of non-cardiac causes). Cross-validation was used to evaluate the performance of the implemented classifier. RESULTS: Δα and IAA, dichotomized at 0.035 (dimensionless) and 3.73 µV, respectively, were the ECG markers most strongly associated with SCD, while TS, dichotomized at 2.5 ms/RR, was the index most strongly related to PFD. When separating SCD victims from the rest of patients, the individual marker with best performance was Δα≥0.035, which, for a fixed specificity (Sp) of 90%, showed a sensitivity (Se) value of 10%, while the combination of Δα and IAA increased Se to 18%. For separation of PFD victims from the rest of patients, the best individual marker was TS ≤ 2.5 ms/RR, which, for Sp=90%, showed a Se of 26%, this value being lower than Se=34%, produced by the combination of Δα and TS. Furthermore, when performing SVM classification into the three reported groups, the optimal combination of risk markers led to a maximum Sp of 79% (Se=18%) for SCD and Sp of 81% (Se=14%) for PFD. CONCLUSIONS: The results shown in this work suggest that it is possible to efficiently discriminate SCD and PFD in a population of CHF patients using ECG-derived risk markers like Δα, TS and IAA.

The Wedensky test predicts malignant ventricular arrhythmias after myocardial infarction.

OBJECTIVES: Better tools are needed for detection of future malignant ventricular arrhythmias post myocardial infarct (MI). Wedensky Modulation (WM) is a new semi-invasive method: A short low-amplitude electrical impulse is applied synchronized to the QRS between a precordial and dorsal thoracic patch, and changes in the following QRS-T are registered. DESIGN: A total of 357 (MI) ICD patients underwent WM testing. QRS-T wavelet analysis provided WM Indexes for the QRS complex (WMI-R) and T wave (WMI-T). Outcome was the time to first occurrence of appropriate device therapy for ventricular arrhythmia. Patients were followed at 6-month intervals for 2 years. RESULTS: No arrhythmia was induced by the testing. Two-year appropriate arrhythmia treatment occurred in 35% (WMI-R positive) versus 25% (WMI-R negative, p = 0.014), and. 45% versus 26% (p = 0.001) for WMI-T positive versus negative. Two-year event rates of WMI-R or WMI-T positive versus WMI-R and WMI-T negative were 36% versus 22% (p = 0.004). In Cox proportional hazard model, the combination of WMI-R and WMI-T was the only statistically significant event predictor (p = 0.003). CONCLUSION: Potentially life-threatening ventricular arrhythmic events could be predicted by the WM test. In combination with other risk factors WMI may be useful in these patients.

Prognostic value of blood pressure measured during hospitalization after acute myocardial infarction: an insight from survival trials.

BACKGROUND: The prognostic value of blood pressure measured during hospitalization after acute myocardial infarction (MI) has not been investigated, particularly with regard to arrhythmic death. METHODS: A total of 3311 placebo patients (2612 men, median age 64 years; range 23-92) from the EMIAT, CAMIAT, SWORD, TRACE and DIAMOND-MI studies with left ventricular ejection fraction less than 40% or asymptomatic ventricular arrhythmia surviving more than 45 days after MI were pooled. Systolic and diastolic blood pressures and pulse pressures were measured soon after MI (median 6 days, range 0-53 days). Mortality up to 2 years was examined using Cox regression. RESULTS: At the 2-year follow-up, after adjustment for age, sex, smoking, previous MI, hypertension, heart rate, New York Heart Association functional class, baseline treatments, study effect and diastolic blood pressure, reduced systolic blood pressure measured during hospitalization after acute MI significantly increased the risk of all-cause mortality [hazard ratio (HR) for 10% increase in systolic blood pressure 0.80, 95% confidence interval (CI) 0.71-0.90; P < 0.001] and arrhythmic mortality (HR 0.73, 95% CI 0.61-0.86; P = 0.001). Reduced diastolic blood pressure significantly increased the risk of all-cause mortality (HR 0.87, 95% CI 0.77-0.98; P = 0.02) and arrhythmic mortality (HR 0.80, 95% CI 0.68-0.93; P = 0.005). CONCLUSION: In post-MI patients with left ventricular ejection fraction less than 40% or asymptomatic ventricular arrhythmia, reduced blood pressure measured during hospitalization after MI significantly predicts all-cause mortality and arrhythmic mortality, and can be reliably used to identify patients who are at risk of dying after MI.

Prognostic impact of demographic factors and clinical features on the mode of death in high-risk patients after myocardial infarction--a combined analysis from multicenter trials.

BACKGROUND: Contemporary information is lacking on the effect of demographic features and clinical features on the specific mode of mortality after myocardial infarction (MI) in the thrombolytic era. HYPOTHESIS: The aims of this study were (1) to examine the risk and trend of a different mode of mortality (i.e., all-cause, arrhythmic, and nonarrhythmic cardiac mortality) in high-risk patients post MI with reduced left ventricular ejection fraction (LVEF) or ventricular arrhythmias; and (2) to assess the predictive value of demographic and clinical variables in the prediction of specific modes of death in high-risk patients post MI in the thrombolytic era. METHODS: In all, 3,431 patients receiving placebo (2,700 men, median age 64 +/- 11 years) from the EMIAT, CAMIAT, SWORD, TRACE, and DIAMOND-MI studies, with LVEF < 40% or ventricular arrhythmia were pooled. Risk factors for mortality among patients surviving > or = 45 days after MI up to 2 years were examined using Cox regression. Short-term survival (from onset of MI to Day 44 after MI) was also examined for TRACE and DIAMOND-MI, in which patients were recruited within 2 weeks of MI. RESULTS: After adjustment for treatment and study effects, age, previous MI/angina, increased heart rate, and higher New York Heart Association functional class increased the risk of all-cause, arrhythmic, and cardiac mortality. Male gender, history of hypertension, low baseline systolic blood pressure, and Q wave were predictive of all-cause and arrhythmic mortality, whereas diabetes was only predictive of all-cause mortality. Smoking habit and atrial fibrillation had no prognostic value. Similar parameters were also predictive of short-term mortality, but not identical. CONCLUSIONS: Our study has shown that in high-risk patients post MI, who have been preselected using LVEF or frequent ventricular premature beats, demographic and clinical features are powerful predictors of mortality in the thrombolytic era. We propose that demographic and clinical factors should be considered when designing risk stratification or survival studies, or when identifying high-risk patients for prophylactic implantable cardiodefibrillator therapy.

Does autonomic function link social position to coronary risk? The Whitehall II study.

BACKGROUND: Laboratory and clinical studies suggest that the autonomic nervous system responds to chronic behavioral and psychosocial stressors with adverse metabolic consequences and that this may explain the relation between low social position and high coronary risk. We sought to test this hypothesis in a healthy occupational cohort. METHODS AND RESULTS: This study comprised 2197 male civil servants 45 to 68 years of age in the Whitehall II study who were undergoing standardized assessments of social position (employment grade) and the psychosocial, behavioral, and metabolic risk factors for coronary disease previously found to be associated with low social position. Five-minute recordings of heart rate variability (HRV) were used to assess cardiac parasympathetic function (SD of N-N intervals and high-frequency power [0.15 to 0.40 Hz]) and the influence of sympathetic and parasympathetic function (low-frequency power [0.04 to 0.15 Hz]). Low employment grade was associated with low HRV (age-adjusted trend for each modality, P< or =0.02). Adverse behavioral factors (smoking, exercise, alcohol, and diet) and psychosocial factors (job control) showed age-adjusted associations with low HRV (P<0.03). The age-adjusted mean low-frequency power was 319 ms2 among those participants in the bottom tertile of job control compared with 379 ms2 in the other participants (P=0.004). HRV showed strong (P<0.001) linear associations with components of the metabolic syndrome (waist circumference, systolic blood pressure, HDL cholesterol, triglycerides, and fasting and 2-hour postload glucose). The social gradient in prevalence of metabolic syndrome was explained statistically by adjustment for low-frequency power, behavioral factors, and job control. CONCLUSIONS: Chronically impaired autonomic function may link social position to different components of coronary risk in the general population.

Preoperative electrocardiographic risk assessment of atrial fibrillation after coronary artery bypass grafting.

INTRODUCTION: This study evaluated the role of surface ECG in assessment of risk of new-onset atrial fibrillation (AF) after coronary artery bypass grafting surgery (CABG). METHODS AND RESULTS: One hundred fifty-one patients (126 men and 25 women; age 65 +/- 10 years) without a history of AF undergoing primary elective and isolated CABG were studied. Standard 12-lead ECGs and P wave signal-averaged ECG (PSAE) were recorded 24 hours before CABG using a MAC VU ECG recorder. In addition to routine ECG measurements, two P wave (P wave complexity ratio [pCR]; P wave morphology dispersion [PMD]) and six T wave morphology descriptors (total cosine R to T [TCRT]; T wave morphology dispersion of ascending and descending part of the T wave [aTMD and dTMD], and others), and three PSAE indices (filtered P wave duration [PD]; root mean square voltage of terminal 20 msec of averaged P wave [RMS20]; and integral of P wave [Pi]) were investigated. During a mean hospital stay of 7.3 +/- 6.2 days after CABG, 40 (26%) patients developed AF (AF group) and 111 remained AF-free (no AF group). AF patients were older (69 +/- 9 years vs 64 +/- 10 years, P = 0.005). PD (135 +/- 9 msec vs 133 +/- 12 msec, P = NS) and RMS20 (4.5 +/- 1.7 microV vs 4.0 +/- 1.6 microV, P = NS) in AF were similar to that in no AF, whereas Pi was significantly increased in AF (757 +/- 230 microVmsec vs 659 +/- 206 microVmsec, P = 0.007). Both pCR (32 +/- 11 vs 27 +/- 10) and PMD (31.5 +/- 14.0 vs 26.4 +/- 12.3) were significantly greater in AF (P = 0.012 and 0.048, respectively). TCRT (0.028 +/- 0.596 vs 0.310 +/- 0.542, P = 0.009) and dTMD (0.63 +/- 0.03 vs 0.64 +/- 0.02, P = 0.004) were significantly reduced in AF compared with no AF. Measurements of aTMD and three other T wave descriptors were similar in AF and no AF. Significant variables by univariate analysis, including advanced age (P = 0.014), impaired left ventricular function (P = 0.02), greater Pi (P = 0.012), and lower TCRT (P = 0.007) or dTMD, were entered into multiple logistic regression models. Increased Pi (P = 0.038), reduced TCRT (P = 0.040), and lower dTMD (P = 0.014) predicted AF after CABG independently. In patients <70 years, a linear combination of increased pCR and lower TCRT separated AF and no AF with a sensitivity of 74% and specificity of 62% (P = 0.005). CONCLUSION: ECG assessment identifies patients vulnerable to AF after CABG. Combination of ECG parameters assessed preoperatively may play an important role in predicting new-onset AF after CABG.

Effects of moderate and vigorous physical activity on heart rate variability in a British study of civil servants.

Physical inactivity and low resting heart rate variability (HRV) are associated with increased coronary heart disease incidence. In the Whitehall II study of civil servants aged 45-68 years (London, United Kingdom, 1997-1999), the strength of the association of moderate and vigorous activity with higher HRV was examined. Five-minute recordings of heart rate and HRV measures were obtained from 3328 participants. Calculated were time domain (standard deviation of NN intervals) and high-frequency-power measures as indicators of cardiac parasympathetic activity and low-frequency power of parasympathetic-sympathetic balance. Leisure-time physical activity (metabolic equivalent-hours per week) was categorized as moderate (>or=3-<5) and vigorous (>or=5). Moderate and vigorous physical activity were associated with higher HRV and lower heart rate. For men, linear trends of higher low-frequency power with increasing quartile of vigorous activity (304.6 (low), 329.0, 342.4, 362.5 (high); p < 0.01) and lower heart rate with increasing quartile of moderate activity (69.6 (low), 69.2, 68.9, 67.8 (high); p < 0.05) were found. These associations remained significant after adjustment for smoking and high alcohol intake. For men whose body mass index was >25 kg/m(2), vigorous activity was associated with HRV levels similar to those for normal-weight men who engaged in no vigorous activity. Vigorous activity was associated with higher HRV, representing a possible mechanism by which physical activity reduces coronary heart disease risk.