Early repolarization, left ventricular diastolic function, and left atrial size in professional soccer players

Recent data have suggested a relation among long-term endurance sport practice, left atrial remodeling, and atrial fibrillation. We investigated the influence of an increased vagal tone, represented by the early repolarization (ER) pattern, on diastolic function and left atrial size in professional soccer players. Fifty-four consecutive athletes underwent electrocardiography, echocardiography, and exercise testing as part of their preparticipation screening. Athletes were divided into 2 groups according to presence or absence of an ER pattern, defined as a ST-segment elevation at the J-point (STE) > or =0.1 mm in 2 leads. For linear comparisons average STE was calculated. Mean age was 24 +/- 4 years. Twenty-five athletes (46%) showed an ER pattern. Athletes with an ER pattern had a significant lower heart rate (54 +/- 9 vs 62 +/- 11 beats/min, p = 0.024), an increased E/e' ratio (6.1 +/- 1.2 vs 5.1 +/- 1.0, p = 0.002), and larger volumes of the left atrium (25.6 +/- 7.3 vs 21.8 +/- 5.0 ml/m(2), p = 0.031) compared to athletes without an ER pattern. There were no significant differences concerning maximum workload, left ventricular dimensions, and systolic function. Univariate regression analysis revealed significant correlations among age, STE, and left atrial volume. In a stepwise multivariate regression analysis age, STE and e' contributed independently to left atrial size (r = 0.659, p <0.001). In conclusion, athletes with an ER pattern had an increased E/e' ratio, reflecting a higher left atrial filling pressure, contributing to left atrial remodeling over time.

Non-water-suppressed proton MR spectroscopy improves spectral quality in the human spinal cord

Magnetic resonance spectroscopy enables insight into the chemical composition of spinal cord tissue. However, spinal cord magnetic resonance spectroscopy has rarely been applied in clinical work due to technical challenges, including strong susceptibility changes in the region and the small cord diameter, which distort the lineshape and limit the attainable signal to noise ratio. Hence, extensive signal averaging is required, which increases the likelihood of static magnetic field changes caused by subject motion (respiration, swallowing), cord motion, and scanner-induced frequency drift. To avoid incoherent signal averaging, it would be ideal to perform frequency alignment of individual free induction decays before averaging. Unfortunately, this is not possible due to the low signal to noise ratio of the metabolite peaks. In this article, frequency alignment of individual free induction decays is demonstrated to improve spectral quality by using the high signal to noise ratio water peak from non-water-suppressed proton magnetic resonance spectroscopy via the metabolite cycling technique. Electrocardiography (ECG)-triggered point resolved spectroscopy (PRESS) localization was used for data acquisition with metabolite cycling or water suppression for comparison. A significant improvement in the signal to noise ratio and decrease of the Cramér Rao lower bounds of all metabolites is attained by using metabolite cycling together with frequency alignment, as compared to water-suppressed spectra, in 13 healthy volunteers.

The esophageal ECG as a novel technique for ambulant heart rhythm monitoring

Introduction: Diagnosing arrhythmias by conventional Holter-ECG can be cumbersome because of artifacts, skin irritation and poor P-waves. In contrast, esophageal electrocardiography (eECG) is promising due to the anatomic relationship of the esophagus to the atria and its favorable bioelectric properties. Methods used: In an ambulant setting, we recorded eECGs from 10 volunteers with a novel, highly-miniaturized eECG recorder that is worn discretely behind the ear (1.5×1.8×5cm, 22grams). The device continuously records two eECG leads during 3 days with 500Hz sampling frequency and 24-bit resolution. Results: Mean ± SD recording time was 21.7±19.6 hours (max. 60 hours). Test persons were not limited in daily activities (e.g. eating, speaking) and only complained mild discomfort during probe insertion, which subsided later on. During 99.8% of time, the recorder acquired signals appropriate for further analysis. In unfiltered data, QRS complexes and P-waves were identifiable during >98% of time. P waves had higher amplitudes as compared to surface ECG (0.71 ± 0.42mV vs. 0.16 ± 0.03mV, p = 0.004). No complications occurred. Conclusion: Ambulatory eECG recording is safe, well tolerated and promising due to excellent P-wave detection, overcoming some limitations of conventional Holter ECG.

Unexplained syncope--is screening for carotid sinus hypersensitivity indicated in all patients aged >40 years?

OBJECTIVE: To determine the frequency, age distribution and clinical presentation of carotid sinus hypersensitivity (CSH) among 373 patients (age range 15-92 years) referred to two autonomic referral centres during a 10-year period. METHODS: Carotid sinus massage (CSM) was performed both supine and during 60 degree head-up tilt. Beat-to-beat blood pressure, heart rate and a three-lead electrocardiography were recorded continuously. CSH was classified as cardioinhibitory (asystole > or = 3 s), vasodepressor (systolic blood pressure fall > or = 50 mm Hg) or mixed. All patients additionally underwent autonomic screening tests for orthostatic hypotension and autonomic failure. RESULTS: CSH was observed in 13.7% of all patients. The diagnostic yield of CSM was nil in patients aged < 50 years (n = 65), 2.4% in those aged 50-59 years (n = 82), 9.1% in those aged 60-69 years (n = 77), 20.7% in those aged 70-79 years (n = 92) and reached 40.4% in those > 80 years (n = 57). Syncope was the leading clinical symptom in 62.8%. In 27.4% of patients falls without definite loss of consciousness was the main clinical symptom. Mild and mainly systolic orthostatic hypotension was recorded in 17.6%; evidence of sympathetic or parasympathetic dysfunction was found in none. CONCLUSIONS: CSH was confirmed in patients > 50 years, the incidence steeply increasing with age. The current European Society of Cardiology guidelines that recommend testing for CSH in all patients > 40 years with syncope of unknown aetiology may need reconsideration. Orthostatic hypotension was noted in some patients with CSH, but evidence of sympathetic or parasympathetic failure was not found in any of them.

Sex differences in cryptogenic stroke with patent foramen ovale

BACKGROUND: Sex differences in patients with patent foramen ovale (PFO) and cryptogenic stroke have not been systematically analyzed. We aimed to determine sex influences on demographics, vascular risk factors, clinical manifestations, stroke location, and clinical outcome. METHODS: One thousand two hundred eighty-eight consecutive patients with ischemic stroke or transient ischemic attack (TIA) were admitted to a single stroke center. All patients underwent a complete stroke workup including clinical examination, standard blood tests, cerebral and vascular imaging, transesophageal echocardiography, and 24-hour electrocardiography. In 500 patients, no definite etiology could be established (cryptogenic stroke/TIA). Of them, 167 patients (107 men and 60 women, mean age 52 +/- 13 years) had an PFO. RESULTS: The prevalence of PFO in patients with cryptogenic stroke or TIA was higher in men than in women (38% vs 28%, P = .014). Stroke severity and the prevalence of risk factors did not differ between the 2 sexes. There was an independent association between male sex and stroke location in the posterior cerebral circulation (OR 3.0, 95% CI 1.4-6.5, P = .006). Men and women did not differ in respect to PFO grade, prevalence of right-to-left shunt at rest, or coexistence of atrial septal aneurysm. Clinical outcome at 3 months was similar in both sexes. CONCLUSION: Patent foramen ovale was more prevalent in men than in women with cryptogenic stroke. There were no sex influences on age, risk factors, echocardiographic characteristics of PFO, or clinical outcome. Male sex was independently associated with stroke in the posterior cerebral circulation.

Organized inpatient (stroke unit) care in very old patients

BACKGROUND AND PURPOSE: It is unclear whether very old patients benefit from organized inpatient (stroke unit) care. The aim of this work was to compare the clinical outcome of patients with first-ever ischemic stroke aged either >or=80 or <80 years who were treated conservatively (without cerebral revascularization) in a university-based stroke unit. PATIENTS AND METHODS: We included 147 (11%) patients >or=80 years and 1241 (89%) patients, <80 years. All patients underwent clinical examination, blood tests, electrocardiography (ECG), brain imaging and cerebrovascular ultrasound. Additional investigations were done at the discretion of the treating physician. The modified Rankin scale (mRS) score was used to assess the 3-month outcome (favorable: mRS, 0-1; poor: mRS, 2-6; death of any cause). RESULTS: Stroke severity did not differ between both groups [median National Institutes of Health Stroke Scale (NIHSS) score, 4]. Younger patients underwent magnetic resonance (MR) imaging of the brain, MR and catheter angiography and echocardiography (p<0.001) more frequently, whereas older patients underwent computed tomography of the brain and 24-hour ECG (p<0.001) more frequently. Stroke prevention included clopidogrel (p<0.001) and heparin (p=0.047) more often in older patients and aspirin (p=0.016) in younger patients. Recurrent ischemic events were similarly frequent in old (7%) and young (5%) patients. Favorable outcome was equally prevalent in old (71%) and young (76%) patients, whereas mortality was higher in older patients (7 and 3%, p=0.007). Admission NIHSS score >or=12 was the only independent predictor of unfavorable outcome (odds ratio, 19.6; 95% confidence interval, 9.7-39.6; p<0.001). CONCLUSION: Our work provides further evidence that also the oldest patients may benefit from conservative stroke unit care.

The optimal lead insertion depth for esophageal ECG recordings with respect to atrial signal quality

BACKGROUND Diagnosing supraventricular arrhythmias by conventional long-term ECG can be cumbersome because of poor p-waves. Esophageal long-term electrocardiography (eECG) has an excellent sensitivity for atrial signals and may overcome this limitation. However, the optimal lead insertion depth (OLID) is not known. METHODS We registered eECGs at different lead insertion depths in 27 patients and analyzed 199,716 atrial complexes with respect to signal amplitude and slope. Correlation and regression analyses were used to find a criterion for OLID. RESULTS Atrial signal amplitudes and slopes significantly depend on lead insertion depth. OLID correlates with body height (rSpearman=0.71) and can be estimated by OLID [cm]=0.25*body height[cm]-7cm. At this insertion depth, we recorded the largest esophageal atrial signal amplitudes (1.27±0.86mV), which were much larger compared to conventional surface lead II (0.19±0.10mV, p<0.0001). CONCLUSION The OLID depends on body height and can be calculated by a simple regression formula.

Association of congenital, diffuse electrical disease in children with normal heart: sick sinus syndrome, intraventricular conduction block, and monomorphic ventricular tachycardia.

INTRODUCTION Rhythm disturbances in children with structurally normal hearts are usually associated with abnormalities in cardiac ion channels. The phenotypic expression of these abnormalities ("channelopathies") includes: long and short QT syndromes, Brugada syndrome, congenital sick sinus syndrome, catecholaminergic polymorphic ventricular tachycardia, Lènegre-Lev disease, and/or different degrees of cardiac conduction disease. METHODS The study group consisted of three male patients with sick sinus syndrome, intraventricular conduction disease, and monomorphic sustained ventricular tachycardia. Clinical data and results of electrocardiography, Holter monitoring, electrophysiology, and echocardiography are described. RESULTS In all patients, the ECG during sinus rhythm showed right bundle branch block and long QT intervals. First-degree AV block was documented in two subjects, and J point elevation in one. A pacemaker was implanted in all cases due to symptomatic bradycardia (sick sinus syndrome). Atrial tachyarryhthmias were observed in two patients. The common characteristic ventricular arrhythmia was a monomorphic sustained ventricular tachycardia, inducible with ventricular stimulation and sensitive to lidocaine. In one patient, radiofrequency catheter ablation was successfully performed. No structural abnormalities were found in echocardiography in the study group. CONCLUSION Common clinical and ECG features suggest a common pathophysiology in this group of patients with congenital severe electrical disease.

Multiple independent genetic factors at NOS1AP modulate the QT interval in a multi-ethnic population.

Extremes of electrocardiographic QT interval are associated with increased risk for sudden cardiac death (SCD); thus, identification and characterization of genetic variants that modulate QT interval may elucidate the underlying etiology of SCD. Previous studies have revealed an association between a common genetic variant in NOS1AP and QT interval in populations of European ancestry, but this finding has not been extended to other ethnic populations. We sought to characterize the effects of NOS1AP genetic variants on QT interval in the multi-ethnic population-based Dallas Heart Study (DHS, n = 3,072). The SNP most strongly associated with QT interval in previous samples of European ancestry, rs16847548, was the most strongly associated in White (P = 0.005) and Black (P = 3.6 x 10(-5)) participants, with the same direction of effect in Hispanics (P = 0.17), and further showed a significant SNP x sex-interaction (P = 0.03). A second SNP, rs16856785, uncorrelated with rs16847548, was also associated with QT interval in Blacks (P = 0.01), with qualitatively similar results in Whites and Hispanics. In a previously genotyped cohort of 14,107 White individuals drawn from the combined Atherosclerotic Risk in Communities (ARIC) and Cardiovascular Health Study (CHS) cohorts, we validated both the second locus at rs16856785 (P = 7.63 x 10(-8)), as well as the sex-interaction with rs16847548 (P = 8.68 x 10(-6)). These data extend the association of genetic variants in NOS1AP with QT interval to a Black population, with similar trends, though not statistically significant at P<0.05, in Hispanics. In addition, we identify a strong sex-interaction and the presence of a second independent site within NOS1AP associated with the QT interval. These results highlight the consistent and complex role of NOS1AP genetic variants in modulating QT interval.

Heart rate variability in response to pain stimulus in VLBW infants followed longitudinally during NICU stay.

The objective of this longitudinal study, conducted in a neonatal intensive care unit, was to characterize the response to pain of high-risk very low birth weight infants (<1,500 g) from 23 to 38 weeks post-menstrual age (PMA) by measuring heart rate variability (HRV). Heart period data were recorded before, during, and after a heel lanced or wrist venipunctured blood draw for routine clinical evaluation. Pain response to the blood draw procedure and age-related changes of HRV in low-frequency and high-frequency bands were modeled with linear mixed-effects models. HRV in both bands decreased during pain, followed by a recovery to near-baseline levels. Venipuncture and mechanical ventilation were factors that attenuated the HRV response to pain. HRV at the baseline increased with post-menstrual age but the growth rate of high-frequency power was reduced in mechanically ventilated infants. There was some evidence that low-frequency HRV response to pain improved with advancing PMA.

Changes in the PQRST intervals and heart rate variability associated with rewarming in two newborns undergoing hypothermia therapy.

BACKGROUND: Little is known about the effects of hypothermia therapy and subsequent rewarming on the PQRST intervals and heart rate variability (HRV) in term newborns with hypoxic-ischemic encephalopathy (HIE). OBJECTIVES: This study describes the changes in the PQRST intervals and HRV during rewarming to normal core body temperature of 2 newborns with HIE after hypothermia therapy. METHODS: Within 6 h after birth, 2 newborns with HIE were cooled to a core body temperature of 33.5 degrees C for 72 h using a cooling blanket, followed by gradual rewarming (0.5 degrees C per hour) until the body temperature reached 36.5 degrees C. Custom instrumentation recorded the electrocardiogram from the leads used for clinical monitoring of vital signs. Generalized linear mixed models were calculated to estimate temperature-related changes in PQRST intervals and HRV. Results: For every 1 degrees C increase in body temperature, the heart rate increased by 9.2 bpm (95% CI 6.8-11.6), the QTc interval decreased by 21.6 ms (95% CI 17.3-25.9), and low and high frequency HRV decreased by 0.480 dB (95% CI 0.052-0.907) and 0.938 dB (95% CI 0.460-1.416), respectively. CONCLUSIONS: Hypothermia-induced changes in the electrocardiogram should be monitored carefully in future studies.

Energy expenditure, body-part discomfort and mental work load among nurses

The purpose of this prospective observational field study was to present a model for measuring energy expenditure among nurses and to determine if there was a difference between the energy expenditure of nurses providing direct care to adult patients on general medical-surgical units in two major metropolitan hospitals and a recommended energy expenditure of 3.0 kcal/minute over 8 hours. One-third of the predicted cycle ergometer VO2max for the study population was used to calculate the recommended energy expenditure.^ Two methods were used to measure energy expenditure among participants during an 8 hour day shift. First, the Energy Expenditure Prediction Program (EEPP) developed by the University of Michigan Center for Ergonomics was used to calculate energy expenditure using activity recordings from observation (OEE; n = 39). The second method used ambulatory electrocardiography and the heart rate-oxygen consumption relationship (HREE; n = 20) to measure energy expenditure. It was concluded that energy expenditure among nurses can be estimated using the EEPP. Using classification systems from previous research, work load among the study population was categorized as "moderate" but was significantly less than (p = 0.021) 3.0 kcal/minute over 8 hours or 1/3 of the predicted VO2max.^ In addition, the relationships between OEE, body-part discomfort (BPCDS) and mental work load (MWI) were evaluated. The relationships between OEE/BPCDS and OEE/MWI were not significant (p = 0.062 and 0.091, respectively). Among the study population, body-part discomfort significantly increased for upper arms, mid-back, lower-back, legs and feet by mid-shift and by the end of the shift, the increase was also significant for neck and thighs.^ The study also provided documentation of a comprehensive list of nursing activities. Among the most important findings were the facts that the study population spent 23% of the workday in a bent posture, walked an average of 3.14 miles, and spent two-thirds of the shift doing activities other than direct patient care, such as paperwork and communicating with other departments. A discussion is provided regarding the ergonomic implications of these findings. ^

Fractional Flow Reserve–Guided PCI for Stable Coronary Artery Disease

Background We hypothesized that in patients with stable coronary artery disease and stenosis, percutaneous coronary intervention (PCI) performed on the basis of the fractional flow reserve (FFR) would be superior to medical therapy. Methods In 1220 patients with stable coronary artery disease, we assessed the FFR in all stenoses that were visible on angiography. Patients who had at least one stenosis with an FFR of 0.80 or less were randomly assigned to undergo FFR-guided PCI plus medical therapy or to receive medical therapy alone. Patients in whom all stenoses had an FFR of more than 0.80 received medical therapy alone and were included in a registry. The primary end point was a composite of death from any cause, nonfatal myocardial infarction, or urgent revascularization within 2 years. Results The rate of the primary end point was significantly lower in the PCI group than in the medical-therapy group (8.1% vs. 19.5%; hazard ratio, 0.39; 95% confidence interval [CI], 0.26 to 0.57; P<0.001). This reduction was driven by a lower rate of urgent revascularization in the PCI group (4.0% vs. 16.3%; hazard ratio, 0.23; 95% CI, 0.14 to 0.38; P<0.001), with no significant between-group differences in the rates of death and myocardial infarction. Urgent revascularizations that were triggered by myocardial infarction or ischemic changes on electrocardiography were less frequent in the PCI group (3.4% vs. 7.0%, P=0.01). In a landmark analysis, the rate of death or myocardial infection from 8 days to 2 years was lower in the PCI group than in the medical-therapy group (4.6% vs. 8.0%, P=0.04). Among registry patients, the rate of the primary end point was 9.0% at 2 years. Conclusions In patients with stable coronary artery disease, FFR-guided PCI, as compared with medical therapy alone, improved the outcome. Patients without ischemia had a favorable outcome with medical therapy alone. (Funded by St. Jude Medical; FAME 2 ClinicalTrials.gov number, NCT01132495 .).

Third degree atrioventricular block and accelerated idioventricular rhythm associated with a heart base chemodectoma in a syncopal Rottweiler.

A 7-year-old male intact Rottweiler was presented with a 1-week history of lethargy, anorexia, vomiting and multiple syncopal events. The results of the clinical examination and electrocardiography were consistent with a third degree atrioventricular block and an intermittent accelerated idioventricular rhythm. Haematology, serum biochemistry, serology for Borrelia burgdorferi, blood culture, total T4, thoracic radiography and echocardiography did not reveal the cause of the arrhythmia. Response to medical treatment with isoproterenol was poor. Pacemaker placement was declined by the owners and the dog was euthanized at their request. Histopathological examination of the heart revealed a chemodectoma at the base of the heart. There was no neoplastic infiltration of the conduction tissue. Potential mechanisms explaining the association of the arrhythmias and the tumour, such as vagal stimulation and neuroendocrine factors are discussed.

Clinical role of atrial arrhythmias in patients with arrhythmogenic right ventricular dysplasia

BACKGROUND: The clinical role of atrial fibrillation/atrial flutter (AF-AFl) and variables predicting these arrhythmias are not well defined in patients with arrhythmogenic right ventricular dysplasia (ARVD). We hypothesized that transthoracic echocardiography (TTE) and 12-lead electrocardiography (ECG) would be helpful in predicting AF-AFl in these patients. METHODS AND RESULTS: ECGs and TTEs of 90 patients diagnosed with definite or borderline ARVD (2010 Task Force Criteria) were analyzed. Data were compared in (1) patients with AF-AFl and (2) all other patients. A total of 18 (20%) patients experienced AF-AFl during a median follow-up of 5.8 years (interquartile range 2.0-10.4). Kaplan-Meier analysis revealed reduced times to AF-AFl among patients with echocardiographic RV fractional area change <27% (P<0.001), left atrial diameter ≥24.4 mm/m(2)(parasternal long-axis, P=0.001), and right atrial short-axis diameter ≥22.1 mm/m(2)(apical 4-chamber view, P=0.05). From all ECG variables, P mitrale conferred the highest hazard ratio (3.37, 95% confidence interval 0.92-12.36, P=0.067). Five patients with AF-AFl experienced inappropriate implantable cardioverter-defibrillator (ICD) shocks compared with 4 without AF-AFl (36% vs. 9%, P=0.03). AF-AFl was more prevalent in heart-transplant patients and those who died of cardiac causes (56% vs. 16%, P=0.014). CONCLUSIONS: AF-AFl is associated with inappropriate ICD shocks, heart transplantation, and cardiac death in patients with ARVD. Evidence of reduced RV function and atrial dilation helps to identify the ARVD patients at increased risk for AF-AFl.