Determination of left ventricular volume by two-dimensional echocardiography: comparison with magnetic resonance imaging

Left ventricular volume was determined in 12 healthy volunteersusing a newly developed two-dimensional echocardio-graphic delineationmethod. The results were compared with those of magnetic resonanceimaging, which served as the method of reference. Left ventricularend-diastolic volume was 123 ± 12 ml, echocardiographicallydefined, and 121 ± 12 ml calculated with magnetic resonanceimaging. End-systolic volume was 41 ± 7 ml on echocardiographyand 37±6 ml on magnetic resonance imaging. Left ventricularejection fraction was 67 ± 4%, echocardiographicallydefined, and 70 ± 5%, calculated with magnetic resonanceimaging. There was no statistical difference for any of themeasured parameters. Interstudy and inter-observer variabilitywas minimal. In conclusion, in healthy volunteers left ventricularvolume was accurately defined, using this newly developed two-dimensionalechocardiographic delineation method. During endocardial delineationa dynamic display is continuously available on a second window,allowing precise visual edge-detection. Moreover, correctionscan be made easily and quickly. These two advantages enhancethe accuracy of the method, even in cases of poor echogenicity.     

Ventricular Arrhythmias in Apparently Healthy Subjects

While it is assumed that the normal heart does not predispose to serious arrhyilimias, several conditions are now being recognized as being associated with short-lasting ventricular arrhythmias. It also becomes clear that idiopathic VT (or repetitive monomorphic VT) sometimes exists on the background of a compromised heart. Whether this dysfunction is due to the arrhythmia or vice versa is not evident. Finally, VF occurs in patients who, at a first glance, have no apparent heart disease, and it is then called idiopathic VF. These complex electrical abnormalities probably reflect disorders, which often are genetically determined. Recognition of these syndromes, often characterized by abnormal repolarization or a disturbed autonomic function is possible if appropriate techniques are used.     

Heart rate increment analysis is not effective for sleep-disordered breathing screening in patients with chronic heart failure

Frequency domain analysis of heart rate variation has been suggested as an effective screening tool for sleep-disordered breathing (SDB) in the general population. The aim of this study was to assess this method in patients with chronic congestive heart failure (CHF). We included prospectively 84 patients with stable CHF, left ventricular ejection fraction (LVEF) <45% and sinus rhythm. The patients underwent polygraphy to measure the apnoea/hypopnoea index (AHI) and simultaneous Holter electrocardiogram monitoring to measure the power spectral density of the very low frequency component of the heart rate increment, expressed as the percentage of total power spectral density [% very low frequency increment (%VLFI)]. %VLFI could be determined in 54 patients (mean age, 52.8 ± 12.3 years; LVEF, 33.5 ± 9.8%). SDB defined as AHI ≥15 h⁻¹ was diagnosed in 57.4% of patients. Percent VLFI was not correlated with AHI ( r  =   0.12). Receiver-operating characteristic curves constructed using various AHI cut-offs (5–30 h⁻¹) failed to identify a %VLFI cut-off associated with SDB. The 2.4% VLFI cut-off recommended for the general population of patients with suspected SDB had low specificity (35%) and low positive and negative predictive values (35% and 54%, respectively). Heart rate increment analysis has several limitations in CHF patients and cannot be recommended as an SDB screening tool in the CHF population.     

Global versus domain-specific statuses in identity research: a comparison of two self-report measures

The present study explored the potential usefulness of global identity statuses (ideological identity) as opposed to domain-specific statuses (occupation, religion, politics) using self-report measures rather than identity interviews. A total of 339 college students from two colleges in Belgium (Europe) completed both the Extended Objective Measure of Ego-Identity Status (EOM-EIS) and the Dellas Identity Status Inventory - Occupation, Religious Beliefs, Political Ideology (DISI-ORP). Four types of evidence argued in favour of domain-specific statuses (i.e. low convergence in identity status across domains, moderate convergence between global and domain-specific identity statuses, significant gender differences in domain-specific but not in global identity statuses, and significant associations between identity process and identity content in congruent but not in incongruent domains). In line with earlier research using identity status interviews, it was concluded that adolescent identity is not to be considered a unitary construct and the use of domain-specific identity statuses is recommended whenever possible. Theoretical implications of the findings are discussed in terms of adolescents' temporal spacing of identity concerns. Finally, the limitations of identity questionnaires (additive approach to global identity statuses) are pointed out. Identity interviews (indicative approach to global statuses) can yield a very different picture of identity.     

Clinical Observations with a Dual Sensor Rate Adaptive Single Chamber Pacemaker

The Topaz model 515 (Vitatron B.V.) is a dual sensor rate responsive pacemaker for single chamber stimulation. It can be driven by activity counts (ACT) and QT interval measurements. Inappropriate rate modulation due to one sensor can be corrected by "sensor cross-checking." It was implanted in ten patients (20-86 years) of whom seven had complete heart block and atrial arrhythmias. After implantation T-wave amplitude ranged from 0.9mV-3.5 mV. T-wave sensing ranged from 88%–99% in 9/10 patients at the follow-up of 3 weeks. Eight patients remained in default setting of the activity threshold, after evaluation with a short walking test. An exercise test was performed on all patients. In one test, QT sensing was marginal because of lead implantation in the right ventricular outflow tract. Therefore, this pacing rate was only modulated by ACT sensing. All others were tested with equal contribution of information from both sensors (ACT = QT). In 7/9, rate response was satisfactory. When the treadmill was repeated with ACT in five of these seven patients, rate generally accelerated too fast. In one patient the setting was adjusted to "QT > ACT," because of inappropriate acceleration due to activity sensing, in another it was adjusted to "QT < ACT" because of delayed response to activity. The pacing rate and the ACT during treadmill tests in "QT = ACT" mode were more closely correlated in the first 3 minutes, compared with the last 3 minutes. We feel that rate modulation with this new pacemaker is adequate. Sensor blending and sensor cross-checking are of clinical importance.     

Bradycardiomyopathy: The Case for a Causative Relationship Between Severe Sinus Bradycardia and Heart Failure

Bradycardiomyopathy . A 28‐year‐old man presented with progressive fatigue. Physical examination and ECG revealed severe sinus bradycardia. Echocardiography showed features of noncompaction cardiomyopathy and moderate aortic valve regurgitation. We hypothesized that the chronic volume overload exaggerated by prolonged diastole due to the bradycardia resulted in heart failure and noncompaction cardiomyopathy look‐alike features. After implantation of an AAI pacemaker, his symptoms and signs of cardiomyopathy were fully recovered. (J Cardiovasc Electrophysiol, Vol. pp. 822‐824, July 2010)     

Dental caries and dental care level (restorative index) in children with diabetes mellitus type 1

International Journal of Paediatric Dentistry 2011; 21: 13–22 Introduction. The aim of the study was to investigate caries experience and dental care index in diabetic children and to determine if correlation exists between caries experience and metabolic control, insulin treatment, and the duration of diabetes. Materials and methods. The study group consisted of 52 children and adolescents, 3–16 years of age with type 1 diabetes attending the outpatient diabetic clinic at Ghent University Hospital, Belgium. Fifty healthy subjects recruited from the paediatric dental clinic served as the control group. Caries lesions were assessed using DMF‐index both at cavity and non‐cavity levels. Participants and/or their guardians provided information about oral hygiene habits and dietary habits. Diabetes‐related data (type, duration, insulin regimen) were collected from medical records and completed with the lab data on HbAlc. Conclusion. It became clear that, although children with type 1 diabetes mellitus could be expected to run a potential high caries risk taking into account the diabetes‐associated biological and behavioural alterations, no significant differences were observed regarding caries experience and dental care between diabetic children and healthy controls. The level of untreated dental decay among the diabetic children is, however, considerably high, which was reflected by a significant lower dental attendance.     

Effects of Septal Pacing on P Wave Characteristics: The Value of Three-Dimensional Echocardiography

SZILI-TOROK, T., et al .: Effects of Septal Pacing on P Wave Characteristics: The Value of Three-Dimensional Echocardiography. Interatrial septum (IAS) pacing has been proposed for the prevention of paroxysmal atrial fibrillation. IAS pacing is usually guided by fluoroscopy and P wave analysis. The authors have developed a new approach for IAS pacing using intracardiac echocardiography (ICE), and examined its effects on P wave characteristics. Cross-sectional images are acquired during pullback of the ICE transducer from the superior vena cava into the inferior vena cava by an electrocardiogram- and respiration-gated technique. The right atrium and IAS are then three-dimensionally reconstructed, and the desired pacing site is selected. After lead placement and electrical testing, another three-dimensional reconstruction is performed to verify the final lead position. The study included 14 patients. IAS pacing was achieved at seven suprafossal (SF) and seven infrafossal (IF) lead locations, all confirmed by three-dimensional imaging. IAS pacing resulted in a significant reduction of P wave duration as compared to sinus rhythm (   99.7 ± 18.7   vs   140.4 ± 8.8  ms; P < 0.01   ). SF pacing was associated with a greater reduction of P wave duration than IF pacing (   56.1 ± 9.9   vs   30.2 ± 13.6  ms; P < 0.01   ). P wave dispersion remained unchanged during septal pacing as compared to sinus rhythm (   21.4 ± 16.1   vs   13.5 ± 13.9  ms; NS   ). Three-dimensional intracardiac echocardiography can be used to guide IAS pacing. SF pacing was associated with a greater decrease in P wave duration, suggesting that it is a preferable location to decrease interatrial conduction delay. (PACE 2003; 26[Pt. II]:253–256)