bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of rebreathing potential on bedding for infant use
Authors: Kanetake Jun , Aoki Yasuhiro , Funayama Masato
Published: December 2004

Abstract
Background
: Rebreathing is thought to be associated with sudden infant death syndrome (SIDS). The aim of the present study was to evaluate the rebreathing potential of different types of Japanese infant bedding.

Methods
: The rebreathing potential of various combinations of infant bedding was measured using a mechanically simulated breathing model. The types of bedding included five types of mattresses, four types of o‐nesyo sheets (waterproof sheets) and a towel. The half‐life of the expiratory CO2 concentration, t1/2‐value was calculated as the index of the rebreathing potential. The softness of the bedding was also measured.

Results
: There was a moderate proportional correlation between the t1/2‐value and the softness (correlation coefficient = 0.509). When a new hard infant mattress was used, the t1/2‐values were 13.6−14.1 s, and when o‐nesyo sheet was added, the values were 14.1−16.2 s. When other mattresses were used with the o‐nesyo sheet, the values were 14.1−19.2 s. Adding a towel onto the bedding, the t1/2‐value (18.5−22.3 s) was prolonged without exception.

Conclusion
: It is difficult to estimate the rebreathing potential of the bedding on the basis its appearance or its softness. All infants should be placed on appropriate bedding in case they turn to a prone‐sleeping position. Our recommendations to avoid rebreathing are as follows: (i) a new hard mattress specifically designed for babies should be used; (ii) a towel should not be used; (iii) an o‐nesyo sheet may be used with a new hard infant mattress if necessary.
Congenital dilatation of the bile duct: Changes in diagnostic tools over the past 19 years
Authors: Takaya Junji , Muneyuki Masatoshi , Tokuhara Daisuke , Takada Kohei , Hamada Yoshinori , Kobayashi Yohnosuke
Published: December 2004

Background
: Because of recent improvements in diagnostic procedures, many cases of congenital dilatation of the bile duct (CDBD) have been diagnosed in early life. To determine the mode of presentation and changes in diagnostic tools, medical records of 34 children (25 girls, nine boys) with CDBD who were treated between 1982 and 2000 were reviewed.

Results
: The age at presentation ranged from 0 to 16 years (median 4.9 ± 0.7 years), with two patients being diagnosed using prenatal ultrasonography. Of the 32 patients diagnosed post‐natally, 21 (66%) complained of abdominal pain. There were also 21 (66%) cases of vomiting. Sixteen patients (50%) experienced both these symptoms. Ten (31%) cases presented with jaundice and three (9%) presented with a palpable mass. Ultrasonography was used as a diagnostic tool in 29 cases (85%). The finding of a dilated common bile duct on abdominal ultrasonography was helpful for early diagnosis. Spiral computed tomography was also a useful and accurate imaging method for diagnosis. Anomalous pancreaticobiliary junction (PBJ) was demonstrated in 44% of patients with CDBD. Magnetic resonance cholangiopancreatography, which can be performed non‐invasively, is useful for the diagnosis and pre‐operative assessment of CDBD in children. The average length of time from presentation to diagnosis could be shortened from 46 days (1982−1988) to 13 days (1995−2000).

Conclusion
: Recent improvements in diagnostic procedures make immediate, non‐invasive diagnosis of CDBD and PBJ possible.
Effects of passive smoking on lung function in children
Authors: Nuhoglu Cagatay , Gurul Mehmet , Nuhoglu Yonca , Karatoprak Nihal , Sonmez Esra Onal , Yavrucu Serpil , Ozguner Ahmet
Published: December 2004

Background
: Passive smoking can have significant effects on lung function with reductions in forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced mid‐expiratory flow rate (FEF25‐75%) of between 5 and 10%.

Methods
: Fifty non‐smoking children aged 6−15 years, who had no history of asthma or atopy and no parental history of atopy, were assessed with respect to their lung functions (FEV1, FEV1/FVC, FEF25−75%).

Results
: Thirty‐three of these children were being exposed to environmental tobacco smoke inside their homes, while 17 children were not exposed. In the ‘passive smoker’ group the FEV1, FEV1/FVC and FEF25‐75% values were found to be significantly lower than the non‐smoker control group's values (P = 0.0080, 0.0228 and 0.0003, respectively). The decrease in FEF25‐75% was significantly correlated inversely with the number of cigarettes smoked per day (P = 0.0261).

Conclusions
: There is sufficient evidence to support the notion that environmental tobacco smoke is a serious health burden for children. Considering that recent studies suggest that up to 70% of children grow up in homes with at least one smoker, every effort should be made to reduce these children's exposure to environmental tobacco smoke and to give them a chance to grow up in a more healthy environment.
Celiac disease in children with Down syndrome: Importance of follow‐up and serologic screening
Authors: Cogulu Ozgur , Ozkinay Ferda , Gunduz Cumhur , Cankaya Tufan , Aydogdu Sema , Ozgenc Funda , Kutukculer Necil , Ozkinay Cihangir
Published: December 2004

Background: Celiac disease, also known as gluten‐sensitive enteropathy, is a chronic inflammation disease of the small intestinal mucosa. Detection of Ig‐A antigliadin antibodies (AGA) and antiendomysial antibodies (EMA) in serum is important in the diagnosis and screening for celiac disease. Antiendomysial antibodies have greater sensitivity compared to antigliadin antibodies. It has been reported that the prevalence of celiac disease is higher in children with Down syndrome than the other autoimmune conditions. The aim of the present study was to investigate the incidence of celiac disease in children with Down syndrome, to assess the availability of Ig‐A AGA and EMA for serologic screening, and to highlight the importance of follow‐up for children with Down syndrome.

Methods: Forty‐seven children with Down syndrome without known celiac disease were tested for total blood count, thyroid function tests, immunoglobulin values, Ig‐A AGA and EMA. Duodenal biopsy was performed on eight patients who showed at least one serologically positive marker.

Results: The ages of the children with Down syndrome ranged from 2 to 18 years (30 boys/17 girls). The mean age was 6.55 ± 3.88. Total blood count and immunoglobulin values were normal. Eleven of the 47 patients (23.40%) were found to be serologically positive, 10 (21.28%) having antigliadin antibody concentrations above normal; and six (12.77%) being positive for antiendomysial antibody. In five patients (10.64%), both Ig‐A AGA and EMA concentrations were high and positive. Duodenal biopsies of three of eight cases (37.50%) revealed villous atrophy, lymphocyte infiltration and crypt hyperplasia. Three cases with abnormal biopsy results (100%) were below the 10th percentile for weight and height. Hypo­thyroidism was detected in one of 11 cases where at least one serologic marker was positive.

Conclusion: Children with Down syndrome should be carefully examined in their follow up, and celiac disease should be considered in cases with growth retardation. Ig‐A antigliadin antibodies and EMA are non‐invasive, cheap and readily available serologic screening tests for celiac disease, and the positivity of both markers gives the most reliable result.
Serial changes of plasma nitrate in the acute phase of Kawasaki disease
Authors: Ikemoto Yumiko , Teraguchi Masayuki , Ono Atushi , Kino Minoru , Yoshimura Ken , Kobayashi Yohnosuke
Published: December 2004

Background
: Endogenous nitric oxide (NO) production increases with clinical conditions associated with immune stimulation. In Kawasaki disease (KD), various cytokines play a role in inflammatory reactions in the cardiovascular system. The authors hypothesized that elevated concentrations of nitrate was related to the severity of vasculitis. The aim of the present study was to evaluate serial changes of plasma nitrate concentrations in the acute phase of KD and to consider how NO is related to the inflammatory process of KD and to the coronary artery lesion (CAL).

Methods
: Thirty patients with KD and 20 age‐matched healthy controls were enrolled in the present study. Blood samples were obtained weekly for the first and second months. The patients were divided into two groups: one with CAL (n = 11) and another without CAL (n = 19). Plasma nitrate was measured by high‐performance liquid chromatography.

Results
: In both groups, plasma nitrate increased remarkably from the first week to the third week. Peak concentrations of nitrate (mean ± SD, µmol/L) in each group were as follows: 56.9 ± 23.8 in the CAL(+) group and 68.2 ± 33.8 in the CAL(−) group. Plasma nitrate decreased from the third week to the second month but was still elevated in both groups in comparison with the age‐matched healthy controls. There was no correlation between plasma nitrates and white blood cell count or C‐reactive protein, respectively (r = 0.013, 0.075).

Conclusions
: The results suggest that NO production may not be related to the severity of vascular inflammation and that elevated nitrate during the first month of illness may not be associated with a higher risk of CAL.
Delivery of a healthy newborn using vitrified zygotes that developed from in vitro matured oocytes retrieved from a patient with polycystic ovarian syndrome
Authors: Yoshida Hiroaki , Aono Nobuya , Araki Yasuhisa , Naganuma Takako
Published: December 2004

The aim of this study is to evaluate vitrified zygotes, which were developed from in vitro matured oocytes that were retrieved from a patient with polycystic ovarian syndrome. Oocyte retrieval was performed on day 15 following withdrawal bleeding. The oocytes were incubated for 24 h in human tissue culture medium (TCM)‐199 maturation medium supplemented with 20% filtrated‐mixed patients follicle fluid, follicle stimulating hormone (FSH), and human chorionic gonadotropin (hCG). A total of four immature oocytes were collected. Two of the four oocytes (50.0%) developed to the metaphase‐II stage and, subsequently, two fertilized oocytes were vitrified at the pronuclear stage because a very thin endometrium was not conducive for transfer. One of the two vitrified zygotes was thawed and developed to a 4‐cell cleavage stage embryo within 24 h. Subsequent to the embryo transfer, a healthy newborn was delivered. A successful delivery was ensued by using vitrified zygotes from an anovulatory woman with polycystic ovarian syndrome. (Reprod Med Biol 2003; 2: 87–90)
Cardiac Resynchronization and Implantable Cardioverter Defibrillator Therapy: Preliminary Results from the InSync Implantable Cardioverter Defibrillator Italian Registry
Authors: GASPARINI MAURIZIO , LUNATI MAURIZIO , BOCCHIARDO MARIO , MANTICA MASSIMO , GRONDA EDOARDO , FRIGERIO MARIA , CAPONI DOMENICO , CARBONI ANGELO , BORIANI GIUSEPPE , ZANOTTO GABRIELE , RAVAZZI PIER ANTONIO , CURNIS ANTONIO , PUGLISI ANDREA , KLERSY CATHERINE , VICINI ILARIA , CAVAGLIÀ SERGIO ,   on behalf of the Italian InSync ICD Registry investigators
Published: December 2004

GASPARINI, M., et al.: Cardiac Resynchronization and Implantable Cardioverter Defibrillator Therapy: Preliminary Results From the InSync Implantable Cardioverter Defibrillator Italian Registry. The aim of this study was to evaluate ventricular arrhythmias occurring in recipients of the InSync ICD for the primary and secondary prevention of sudden death. The InSync ICD was implanted in 142 patients (128 men; mean age65 ± 10years) with heart failure (mean NYHA functional Class3.0 ± 0.7) and wide QRS (mean159 ± 33ms). The underlying etiology was ischemic in 55%, idiopathic in 33%, and valvular or hypertensive cardiomyopathy in 12% of patients. The numbers of arrhythmic episodes/100 patient‐months was computed with their 95% CI, assuming a Poisson distribution. Implants were performed in 48 (34%) patients who did not have an ACC/AHA guidelines Class I indication for ICD therapy. A total of 104 patients were compliant for follow‐up visits. During a 9‐month median (range 0.1–24) follow‐up of 104 compliant patients, 19 experienced a total of 94 ventricular arrhythmias, all successfully interrupted or selfterminated, with a median number of two separate episodes, corresponding to a rate of 10 episodes/100 person‐month (95% CI 8–12). A rate of 12 episodes/100 person‐months (95% CI 10–15) was measured in the subgroup of patients with ACC/AHA class I indications, versus two episodes/100 person‐months (95% CI 1–5) in the remainder of the population. Among 12 deaths, 9 were due to heart failure, 1 to a noncardiovascular cause, and 2 to unknown causes. The implantation of ICD in heart failure patients has been prominently extended to primary prevention. Patients without standard ICD indications experienced life‐threatening arrhythmic events. The impact of ICD combined with cardiac resynchronization therapy on arrhythmic profile, mortality, and costs in this subgroup of patients need to be more precisely studied, with a particular focus on the various types of underlying heart disease. (PACE 2003; 26:[Pt. II]:148–151)
Long‐Term Experience with a Preshaped Left Ventricular Pacing Lead
Authors: OLLITRAULT JACKY , RITTER PHILIPPE , MABO PHILIPPE , GARRIGUE STÉPHANE , GROSSIN FRANÇOIS , LAVERGNE THOMAS
Published: December 2004

OLLITRAULT, J., et al.: Long‐Term Experience with a Preshaped Left Ventricular Pacing Lead.
This study describes a long‐term experience with a new LV pacing lead. The study population consisted of 62 patients (85% men,

71 ± 10

years old) with advanced dilated cardiomyopathy, in NYHA Class III or IV despite optimal drug therapy, and a QRS duration >150 ms. Patients in sinus rhythm were implanted with a triple chamber pacemaker to maintain atrioventricular synchrony. A dual chamber pacemaker was implanted in patients in atrial fibrillation for biventricular pacing only. A clinical evaluation and interrogation of the resynchronization pacemaker were performed at implant, at 1 week (W1), one (M1), four (M4), and seven (M7) months after implantation. A longer follow‐up (2 years) is available for patients implanted at the authors institution. LV measurements were pacing threshold at 0.5‐ms pulse duration and pacing impedance. R wave amplitude (mV) was measured at the time of implantation only. The system was successfully implanted in 86% of patients with the latest design of the lead. Mean R wave amplitude at implant was

15 ± 7 mV

and mean pacing impedance was

1054 ± 254 Ω

. Between implant

(n = 38)

and M7

(n = 15)
, pacing threshold rose from0.73 ± 0.54to1.57 ± 0.60 V (P < 0.001). In conclusion, the situs lead was successfully implanted in a high percentage of patients. In addition, low pacing threshold and high impedance measured during follow‐up are consistent with a low pacing current drain, ensuring a durable pulse generator longevity. (PACE 2003; 26[Pt. II]:185–188)
Contributions of High Resolution Electrograms Memorized by DDDR Pacemakers in the Interpretation of Arrhythmic Events
Authors: DEFAYE PASCAL , LECLERCQ JEAN‐FRANÇOIS , GUILLEMAN DANIÈLE , SCANU PATRICE , HAZARD JEAN‐RENÉ , FATEMI MARJANEH , BOURSIER MICHEL , LAMBIEZ MARIE ,   on behalf of the EGM study group
Published: December 2004

DEFAYE, P.,

et al.

: Contributions of High Resolution Electrograms Memorized by DDDR Pacemakers in the Interpretation of Arrhythmic Events.
The accuracy of information retrievable from the memories of DDDR pacing systems has been limited by the absence of actual electrograms confirming the proper sensing of spontaneous cardiac activity versus that of extraneous signals. This study examined the diagnostic power of a new arrhythmia interpretation scheme, which includes the recording and storage of high resolution endocavitary atrial and ventricular electrograms (HREGM). HREGM stored in the memories of new generation pacemakers (PM) in response to nonsustained ventricular tachycardia (NSVT), sustained VT, and atrial arrhythmias were analyzed in a follow‐up registry of 520 patients at 1 month, and 3 to 6 months after implantation of a PM for standard indications. For each sequence of stored HREGM, the accuracy of the PM response was examined, classified as accurate (true positive), versus inaccurate (false positive), versus undetermined, and the relative contribution of the HREGM in verifying the PM diagnosis was measured. During a follow‐up of

4.9 ± 2  months

, 256 (49%) of the 520 patients had an event recorded, which was confirmed to be arrhythmic on the basis of HREGM. Overall, approximately 34% of atrialtachy response (ATR) episodes were confirmed to be appropriate. Similar percentages of episodes were prompted by oversensing of signals unrelated to cardiac arrhythmias, while nearly 12% of the episodes could not be clarified because of such brief duration as to preclude recording of their onset. Approximately one‐third of NSVT, and one‐half of VT detections were false positive. Ventricular oversensing, most often due to myopotential interference in presence of unipolar sensing, and atrial undersensing were both identified as sources of false‐positive detections of ventricular events. The proportion of true‐positive detections was significantly higher in the bipolar (83%) than unipolar configuration. Among 520 PM recipients, miscellaneous episodes of atrial arrhythmias were confirmed by HREGM in 37% of patients within 3 to 6  months of follow‐up. Atrial fibrillation was confirmed in only 6% of patients, of whom over 50% already had histories of atrial fibrillation. The prevalence of unsuspected atrial arrhythmia in this unselected population was lower than previously reported. (PACE 2003; 26[Pt. II]:214–220)
Autocapture Enhancements: Unipolar and Bipolar Lead Compatibility and Bipolar Pacing Capability on Bipolar Leads
Authors: BINNER LUDWIG , MESSENGER JOHN , SPERZEL JOHANNES , BONDKE HANSJÜRGEN , VANDEKERCKHOVE YVES , POORE JOHN , SCHEINER JÖERG , BERKHOF MARC , PARK EULJOON , HOLMSTRÖM NILS , BORNZIN GENE A.
Published: December 2004

BINNER, L., et al.: Autocapture Enhancements: Unipolar and Bipolar Lead Compatibility and Bipolar Pacing Capability on Bipolar Leads.
Beat‐by‐beat Autocapture maximizes device longevity by minimizing stimulus amplitude while assuring patient safety. Currently, Autocapture permits use of only bipolar leads. The authors have devised a detection method that operates with unipolar and bipolar leads and covers all pacing and sensing combinations (but bipolar pace and sense simultaneously). This new detection method for unipolar sensing uses the integral of the negative portion of the unipolar evoked response as a robust capture detection feature. When using bipolar leads, the method provides the flexibility of bipolar or unipolar pacing. In this study, unipolar ventricular intracardiac electrograms (EGMs) were recorded in 71 patients, 73.7 ± 9.9 years of age; 9 with high polarization, 62 with low polarization. High polarization had polished platinum or activated carbon electrodes. Low polarization had TiN, platinized platinum, or IrOx electrodes. The intracardiac EGMs were recorded

544 ± 796

days after implant. The pacemakers performed an automatic capture threshold test while the intracardiac EGM signals were recorded in a programmer. These digitized signals were saved for off‐line analysis. The unipolar evoked response was calculated at up to six (depending on capture threshold) pacing voltages and the polarization integral at 4.5 V and at loss of capture. An automatic calibration algorithm determined if the signal‐to‐noise ratio was adequate for Autocapture operation. Autocapture was possible with 60 of 62 of the low polarizations, and with 6 of 9 of the high polarizations. The average values from the data collected were: average unipolar evoked response

‐ 4.1 ± 2.1  mV

, average peak negative voltage

‐ 10.0 ± 3.7  mV

, average polarization 0.3 ± 0.34 mV, and average signal‐to‐noise ratio (unipolar evoked response/polarization) 38 ± 71. In all cases the algorithm correctly determined the appropriateness of using Autocapture with the electrodes tested and the unipolar evoked response threshold to be used. (PACE 2003; 26[Pt. II]:221–224)
Effects of Septal Pacing on P Wave Characteristics: The Value of Three‐Dimensional Echocardiography
Authors: SZILI‐TOROK TAMAS , BRUINING NICO , SCHOLTEN MARCOEN , KIMMAN GEERT‐JAN , ROELANDT JOS , JORDAENS LUC
Published: December 2004

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)
Pacing of the Atria in Sick Sinus Syndrome Trial: Preventive Strategies for Atrial Fibrillation
Authors: SPITZER STEFAN G. , GAZAREK STEFFEN , WACKER PETRA , MALINOWSKI KLAUS , SCHIBGILLA VOLKER ,   on behalf of the PASTA trial group
Published: December 2004

SPITZER, S.G.,

et al

.: Pacing of the Atria in Sick Sinus Syndrome Trial: Preventive Strategies for Atrial Fibrillation.
This study examines the effects of various atrial lead positions in physiological pacing on the incidence of AF in patients with sick sinus syndrome. The lead is implanted in the RA free wall, in the RA appendage, near the coronary sinus ostium (CSO) or, in dual site RA pacing, in the appendage and the CSO. Since CSO and dual site right atrial pacing aim at modifying the pathological substrate, pacing of two‐thirds of all cardiac cycles is attempted by adapting the basic rate and the rate response option. The results of this study are expected to assist in the development of guidelines for the placement of atrial pacing leads in sick sinus syndrome. (PACE 2003; 26[Pt. II]:268–271)
Hemodynamic Effects of Alternative Atrial Pacing Sites in Patients with Paroxysmal Atrial Fibrillation
Authors: DABROWSKA‐KUGACKA ALICJA , LEWICKA‐NOWAK EWA , KUTARSKI ANDRZEJ , ZAGOŻDŻON PAWEł , ŚWIATECKA GRAŻYNA
Published: December 2004

DABROWSKA‐KUGACKA, A., et al.: Hemodynamic Effects of Alternative Atrial Pacing Sites in Patients with Paroxysmal Atrial Fibrillation.
Recently, multisite atrial pacing has been suggested as an alternative therapy to prevent recurrences of paroxysmal atrial fibrillation (PAF). A study was conducted to compare the acute effects of biatrial (BiA), left atrial (LA), and right atrial appendage (RAA) pacing on cardiac hemodynamics. In 14 patients with PAF and a BiA pacemaker (with leads in the RAA and coronary sinus), cardiac output (CO), right (RV) and left ventricular (LV) filling, RA‐LA contraction delay [PA(m‐t)] and the difference in A wave duration [Adif(m‐p)] at the level of the mitral valve (Adurm) and pulmonary veins (Adurp) during RAA, BiA, and LA pacing were examined by echo‐Doppler measurements. The atrial pacing site did not affect the CO. LA, but not BiA, pacing resulted in delayed RA contraction in comparison with RAA pacing with significant diminution of the RA contribution to RV filling. With LA pacing, the usual right‐to‐left atrial contraction sequence was reversed (PA(m‐t):

8 ± 7

ms control;

5 ± 30

ms RAA;

−10 ± 21

ms BiA;

−72 ± 36 ms

LA; LA versus control versus RAA and versus BiA, P < 0.001. LA and BiA pacing prolonged Adurp

(LA 186 ± 52 ms, BiA 180 ± 45 ms, RAA 153 ± 49 ms; LA and BiA vs RAA, P < 0.01)

. Thus Adurp exceeded Adurm[Adif (m‐p): control 38 ± 40 ms, RAA 7 ± 42 ms, BiA −12 ± 43 ms, LA −20 ± 44 ms; control vs RAA, BiA, and LA; and RAA vs LA, P < 0.05]. The study showed that (1) the atrial pacing site has no influence on global cardiac performance; (2) the hemodynamic effect of BiA pacing is not superior to that of RAA pacing, and LA pacing can even be deleterious; (3) LA pacing reverses the usual right‐to‐left atrial contraction sequence and reduces the RA contribution to RV filling; (4) BiA and LA pacing prolong Adurp due to an altered activation pattern, decreased pulmonary venous return, or increased LA pressure. (PACE 2003; 26[Pt. II]:278–283)
Three‐Dimensional Noncontact Mapping Defines Two Zones of Slow Conduction in the Circuit of Typical Atrial Flutter
Authors: CHEN JIAN , HOFF PER IVAR , ERGA KNUT STÅLE , ROSSVOLL OLE , OHM OLE‐JØRGEN
Published: December 2004

CHEN, J, et al.: Three‐Dimensional Noncontact Mapping Defines Two Zones of Slow Conduction in the Circuit of Typical Atrial Flutter.
The cavotricuspid isthmus (CTI) is a slow conduction area in the circuit of typical atrial flutter. However, conventional methods are limited by the inaccuracy of measurements of distance on the surface of the heart. The aim of the study was to define the conduction properties of the atrial flutter circuit along the tricuspid annulus by using a three‐dimensional noncontact mapping system. In 34 atrial flutter patients (30 men, 4 women; mean age

54 ± 14; 27

counter‐clockwise, 4 clockwise, and 3 both), a noncontact multielectrode array was used to reconstruct electrograms in the right atrium. Isochronal and isopotential propagation mapping was performed during atrial flutter. The conduction velocity was calculated by dividing conduction time by surface distance. The right atrium along the tricuspid annulus was divided into five regions: lateral wall, superior right atrium, septum, septal CTI, and lateral CTI. Conduction velocities were

0.99 ± 0.85, 1.67 ± 1.21, 1.58 ± 1.05, 0.82 ± 0.72

, and

1.68 ± 1.00  m/s

in counter‐clockwise and

0.81 ± 0.71, 2.61 ± 1.90, 1.52 ± 0.91, 0.91 ± 0.80

and

1.91 ± 0.83  m/s

in clockwise, respectively. Conduction velocities were significantly slower in the septal CTI and lateral wall than in the lateral CTI, the septum, and the superior right atrium (P < 0.05). No significant difference was found between the septal CTI and the lateral wall. Conduction within the septal CTI was slower in patients treated with antiarrhythmic agents than in untreated patients (P < 0.05). The septal part of the CTI (but not the lateral CTI) and the lateral wall are slow conduction zones in the atrial flutter circuit, and both may, therefore, be mechanically important for the development of atrial flutter. (PACE 2003; 26[Pt. II]:318–322)
Ventricular Dyssynchrony and Risk Markers of Ventricular Arrhythmias in Nonischemic Dilated Cardiomyopathy:
Authors: FAUCHIER LAURENT , MARIE OLIVIER , CASSET‐SENON DANIELLE , BABUTY DOMINIQUE , COSNAY PIERRE , FAUCHIER JEAN PAUL
Published: December 2004

FAUCHIER, L.,

et al

.: Ventricular Dyssynchrony and Risk Markers of Ventricular Arrhythmias in Nonischemic Dilated Cardiomyopathy: A Study with Phase Analysis of Angioscintigraphy.
Biventricular pacing is a new form of treatment for patients with dilated cardiomyopathy and ventricular dyssynchrony. Limited information is available regarding the relationship between ventricular dyssynchrony and risk markers of ventricular arrhythmias in idiopathic dilated cardiomyopathy (IDC). In 103 patients with IDC, Fourier phase analysis of both ventricles was performed from equilibrium radionuclide angiography (ERNA). The difference between the mean phase of the LV and RV was a measure of interventricular dyssynchrony, and the standard deviations of the mean phases in each ventricle measured intraventricular dyssynchrony. There were no significant differences in inter‐ and intraventricular dyssynchrony between patients with versus without histories of sustained VT or VF, nonsustained VT, abnormal signal‐averaged ECG, or induced sustained monomorphic VT. Dyssynchrony was not related to decreased heart rate variability (HRV). LV and interventricular dyssynchrony were weakly related to QT duration and QT dispersion. During a follow‐up of

27 ± 23  months

, 21 patients had major adverse cardiac events (MACE), including 7 cardiac deaths, 11 progression of heart failure leading to cardiac transplantation, and 3 sustained VT/VF. The only independent predictors of MACE were an increased standard deviation of LV mean phase (P = 0.003), a decreased HRV (standard deviation of normal‐to‐normal intervals, P = 0.004), and histories of previous VT/VF (P = 0.03) or nonsustained VT (P = 0.04). In conclusion, left intraventricular dyssynchrony evaluated with ERNA was an independent predictor of MACE in IDC and was not related to usual risk markers of ventricular arrhythmias. This may have implications for resynchronization therapy and/or the use of implantable cardioverter defibrillators in IDC. (PACE 2003; 26[Pt. II]:352–356)
Abnormal Cardiac Innervation in Patients with Idiopathic Ventricular Fibrillation
Authors: BIFFI MAURO , FALLANI FRANCESCO , BORIANI GIUSEPPE , FANTI STEFANO , KOWOLL LUDOVICA , PETTINATO CINZIA , MONETTI NINO , BRANZI ANGELO
Published: December 2004

BIFFI, M., et al.: Abnormal Cardiac Innervation in Patients with Idiopathic Ventricular Fibrillation.
Idiopathic ventricular fibrillation (VF) is diagnosed in up to nearly 10% of survivors of out‐of‐hospital cardiac arrest. The arrhythmogenic substrate is unknown. This study examined the role of cardiac innervation as a possible contributor to this arrhythmia. Eight patients with idiopathic VF were compared with eight normal subjects (controls) by [123] I metaiodobenzylguanidine SPECT (MIBG), measuring peak uptake, late uptake, and clearance of the nuclear tracer. The left ventricle was divided in 13 segments in the bull's‐eye target plot. Peak and late MIBG uptake was increased in the anterolateral segments (2,3,7,8) compared to the inferoposterior and septal segments, in controls and in patients. No difference was observed between controls and patients in the inferoposterior and septal segments. In contrast, a significantly higher MIBG uptake was observed in patients compared to controls in the anterolateral segments (

94 ± 4%

vs

81 ± 11%, P < 0.03

for peak uptake;

94 ± 5%

vs

79 ± 12%, P < 0.01

for late uptake). No difference was observed in MIBG clearance in any segment in either study group. Cardiac sympathetic innervation is highly heterogeneous, though predominant in anterolateral segments in normal subjects. Patients with idiopathic VF exhibit the same distribution, though have a significantly greater density of sympathetic terminals in the anterolateral segments than controls, which may promote ventricular arrhythmias. (PACE 2003; 26[Pt. II]:357–360)
Noninvasive Study of Ventricular Preexcitation Using Multichannel Magnetocardiography
Authors: FENICI RICCARDO , BRISINDA DONATELLA , NENONEN JUKKA , FENICI PETER
Published: December 2004

FENICI, R., et al.: Noninvasive Study of Ventricular Preexcitation Using Multichannel Magnetocardiography.
In clinical practice, noninvasive classification of ventricular preexcitation (VPX) is usually done with ECG algorithms, which provide only a qualitative localization of accessory pathways. Since 1984, single or multichannel magnetocardiograpy (MMCG) has been used for three‐dimensional localization of VPX sites, but a systematic study comparing the results of ECG and MMCG methods was lacking. This study evaluated the reliability of MMCG in an unshielded electrophysiological catheterization laboratory, and compared VPX classification as achieved with the five most recent ECG algorithms with that obtained by MMCG mapping and imaging techniques. A nine‐channel direct current superconducting quantum interference device (DC‐SQUID) MMCG system (sensitivity is 20 fT/Hz0.5) was used for sequential MMCG from 36 points on the anterior chest wall, within an area

20 × 20 cm

. Twenty‐eight patients with Wolff‐Parkinson‐White syndrome were examined at least twice, on the same day or after several months to test the reproducibility of the measurements. In eight patients, the reproducibility of MMCG was also evaluated using different MCG instrumentation during maximal VPX and/or atrioventricular reentrant tachycardia induced by transesophageal atrial pacing via a nonmagnetic catheter. The results of VPX localization with ECG algorithms and MMCG were compared. Equivalent current dipole, effective magnetic dipole, and distributed currents imaging models were used for the inverse solution. MMCG classification of VPX was found to be more accurate than ECG methods, and also provided additional information for the identification of paraseptal pathways. Furthermore, in patients with complex activation patterns during the delta wave, distributed currents imaging revealed two different activation patterns, suggesting the existence of multiple accessory pathways. (PACE 2003; 26[Pt. II]:431–435)
DDDR Pacing Driven by Contractility Versus DDI Pacing in Vasovagal Syncope:
Authors: DEHARO JEAN‐CLAUDE , BRUNETTO ALBERTO BORRI , BELLOCCI FULVIO , BARBONAGLIA LORELLA , OCCHETTA ERALDO , FASCIOLO LORELLA , BOCCHIARDO MAURIZIO , ROGNONI GIORGIO
Published: December 2004

DEHARO, J.‐C.,

et al

.: DDDR Pacing Driven by Contractility Versus DDI Pacing in Vasovagal Syncope: A Multicenter, Randomized Study.
Recent clinical trials have shown that selected patients with recurrent vasovagal syncope (VVS) may benefit from permanent cardiac pacing. In a previous study using head‐up tilt testing (HUT) the authors demonstrated that the increase in sympathetic activity preceding syncope could be sensed by a microaccelerometer located in the tip of a ventricular pacing lead and used to drive a rate adaptive pacer. They compared in a single blind randomized crossover study, DDDR pacing driven by this system, with conventional DDI pacing in patients with recurrent VVS. Twenty‐three patients (age

61.8 ± 15.2  years

, 19 men) with recurrent VVS were enrolled at seven European centers and underwent implantation of a “MiniLivingD/Best” pacing system. Inclusion criteria were (1) >6 cumulative syncopal episodes or ≥1 syncope within 6 months of a positive HUT, and (2) a positive HUT with bradycardia. Using a crossover study design, the pacemakers were randomly programmed for two successive periods of 6 months to DDDR or DDI mode. The numbers of episodes of syncope and presyncope, and quality‐of‐life (QOL), were assessed at the end of each period. During the 6 months before implant, the mean number of syncopal episodes per patient was

3.2 ± 9

. During pacing in the DDDR mode,

0.09 ± 0.29

syncope/presyncope per patient was observed, while during the DDI period

0.48 ± 0.73

episodes per patient were reported

(P < 0.05)
. QOL scores were77.40 ± 11.32in the DDDR mode versus74.45 ± 14.59in the DDI mode (NS). In patients with recurrent VVS, symptomatic recurrences were less frequent during contractility‐driven DDDR pacing, than during DDI pacing. QOL was similar in the two pacing modes. (PACE 2003; 26[Pt. II]:447–450)
Subthreshold Test Pulses Versus Low Energy Shock Delivery to Estimate High Energy Lead Impedance in Implanted Cardioverter Defibrillator Patients
Authors: VOLLMANN DIRK , LUETHJE LARS , ZENKER DIETER , DOMHOF SEBASTIAN , UNTERBERG CHRISTINA
Published: December 2004

VOLLMANN, D., et al.: Subthreshold Test Pulses Versus Low Energy Shock Delivery to Estimate High Energy Lead Impedance in Implanted Cardioverter Defibrillator Patients.
The high energy lead impedance is valuable for detecting lead failure in ICDs, but until recently shock delivery was necessary for high energy impedance measurement. This study compared the use of subthreshold test pulses and low energy test shocks to estimate the high energy impedance. Immediately after implantation of Ventak Prizm ICDs in 29 patients, the lead impedance was measured with five subthreshold (0.4 μJ) test pulses, 5 low energy (1.1 J) shocks, and two to three high energy

(16 ± 4.5 J)

shocks. The mean impedances measured using high energy shocks, low energy shocks, and subthreshold pulses were

42.0 ± 7.3 Ω, 46.5 ± 8.1 Ω

, and

42.4 ± 7.1 Ω

, respectively. The impedances measured using high and low energy shocks differed significantly

(P <0.0001)

, while those obtained by high energy shocks and low energy pulses did not

(P = 0.63)
. According to the Pearson correlation coefficient, the impedance measurements with subthreshold pulses and low energy shocks were both closely correlated(P < 0.0001)with impedance values determined with high energy shocks. However, while the impedance values tended to be higher when measured with low energy shocks, the concordance correlation coefficient (c) was higher for subthreshold test pulse versus high energy shock(c = 0.92)than for low versus high energy shock(c = 0.73). Furthermore, the intraindividual variability of impedance measurements was lower with subthreshold pulse measurements than with low energy shocks. Compared with low energy shocks, impedance measurement with subthreshold pulses has higher reproducibility and a higher correlation with the impedance obtained by high energy shock delivery. Safe and painless high energy impedance estimation with subthreshold pulses might, therefore, help to detect ICD lead failure during routine follow‐up. (PACE 2003; 26:[Pt. II]:457–460)
Use of the AutoCapture Pacing System with Implantable Defibrillator Leads
Authors: MARENCO JOHN P. , GREENFIELD RUTH ANN , MASSUMI ALI , SYED ZAFFER A. , MCINTYRE TIMOTHY , HARDAGE MICHAEL , LINK MARK S. , HOMOUD MUNTHER K. , ESTES MARK , WANG PAUL J.
Published: December 2004

MARENCO, J.P., et al.: Use of the AutoCapture Pacing System with Implantable Defibrillator Leads.
Introduction: Previous studies using various bipolar pacemaker leads have shown that the AutoCapture (AC) Pacing System is able to verify ventricular capture and regulate pacing output, increasing patient safety with respect to unexpected threshold changes and potentially prolonging device longevity. An increasing number of patients with implantable cardioverter defibrillators (ICDs) require ventricular pacing that contributes to a shortening of longevity of these systems. This prospective study tested the compatibility of the AC system with bipolar ICD leads. Methods: The AC algorithm was evaluated prior to ICD testing in 30 ICD recipients. A single coil, active fixation, true bipolar ventricular lead was implanted in 21 patients, and a dual coil, passive fixation, integrated bipolar ventricular lead was implanted in 9 patients. A ventricular evoked response sensitivity test and an AC threshold test were performed using a pacemaker with the ventricular AC algorithm. Results: AC was recommended in 22/30 (73.3%) of implants, including 20/21 (95.2%) with the single coil and 2/9 (22.2%) with the dual coil lead. Mean polarization was lower (

1.23 ± 0.95 mV

vs

3.70 ± 2.33 mV, P = 0.013

) while the mean evoked response was higher (

18.04 ± 8.29 mV

vs

10.13 ± 4.22 mV, P = 0.002

) with the single coil leads. Conclusion: Automatic threshold tracking using the AC is compatible with ICD leads. Leads with lower polarization and greater evoked response are more likely to result in recommendation of AC use. Use of this system offers the potential for increasing ICD generator longevity and improving patient safety in response to late unexpected threshold increases. (PACE 2003; 26[Pt. II]:471–473)
Sinus Node Dysfunction and Impairment of Global Atrial Conduction Time After High Rate Atrial and Ventricular Pacing in Dogs
Authors: ZUPAN I. , KOŽELJ M. , BRECELJ A. , RAKOVEC P.
Published: December 2004

ZUPAN, I., et al.: Sinus Node Dysfunction and Impairment of Global Atrial Conduction Time After High Rate Atrial and Ventricular Pacing in Dogs.
It has been shown in animals and humans that AF shortens the atrial refractory period and impairs its rate adaptation. The aim of the study was to evaluate the effects of high rate pacing on sinus node function and intraatrial conduction. Eight dogs were subjected to rapid atrial pacing (AP) at a rate of 400 beats/min for 16 days. After a complete recovery of left ventricular function, they underwent rapid ventricular pacing (VP) at 240 beats/min of equal duration. Sinus node recovery time (SNRT) was measured after pacing at 150, 160, and 170 beats/min. P wave duration was measured on a surface ECG recorded at a paper speed of 200 mm/s. Measurements were performed at baseline, immediately after AP or VP, and four weeks after termination of AP or VP. SNRT immediately after AP and VP was significantly prolonged at all three pacing rates

(P < 0.03)

. P wave duration increased significantly after either type of pacing

(AP: 74.3 ± 6.4 ms, VP: 70.0 ± 3.8 ms)

compared with baseline values

(60.6 ± 6.2 ms, P < 0.05)

. Rapid AP and VP induces sinus node dysfunction and prolongs intraatrial conduction time. The effects of sustained AP and VP on sinus node function and atrial myocardium returned toward control values 4 weeks after cessation of pacing. The authors hypothesize that reversible electrical remodeling occurs both in the sinus node and in the atrial myocardium. (PACE 2003; 26[Pt. II]:507–510)
Influence of Mobile Magnetic Resonance Imaging on Implanted Pacemakers
Authors: KISHI RYOJI , MATSUMOTO NAOKI , NAKAZAWA KIYOSHI , TAKAGI AKIHIKO , SAKURAI TSUNEHARU , NANKE TOSHIHIKO , WATANABE YOSHIYUKI , MIYAZU OSAMU , HARADA TOMOO , KOBAYASHI SHINICHI , MIYAKE* FUMIHIKO
Published: December 2004

KISHI, R., et al.: Influence of Mobile Magnetic Resonance Imaging on Implanted Pacemakers.
Purpose: Mobile magnetic resonance imaging (MRI) systems will be widely used in Japan. When traveling, mobile MRI generate alternating electromagnetic waves which may cause electromagnetic interference (EMI). This study was designed to determine whether this may influence the function of implanted pacemakers (PM). Methods and Results: The influence of the static magnetic fields was tested in the first method using a PM‐human model (Phantom). Magnetic force was simultaneously measured. The PM was switched to the magnet mode within 90 cm from the vehicle, where the magnetic force was = 2 mT. In the second method, six phantoms were placed on the side of the road, facing in three different directions in X‐Y‐Z axis orientations, at 1.3 m and 2.0 m above the ground. The mobile MRI passed by at a distance of 1 m from the phantoms at the speed of 20 or 40 km/h. In these experiments, magnet mode switch of the PM was observed for 2 seconds when the vehicle passed close to the phantoms, though no electrical noise was recorded. Conclusion: Mobile MRI vehicles can switch a PM to magnet mode when the distance between patient and vehicle is <90 cm, regardless of whether the vehicle is moving or at a stop. Patients with implanted PM should not approach within <1 m of a mobile MRI. No other EMI‐induced PM dysfunction was detected. (PACE 2003; 26[Pt. II]:527–529)
Assessment of Heart Rate Turbulence in the Acute Phase of Myocardial Infarction for Long‐Term Prognosis
Authors: SADE ELIF , AYTEMIR KUDRET , OTO ALI , NAZLI NASH , ÖZMEN FERHAN , ÖZKUTLU HILMI , TOKGÖZOGLU LALE , AKSÖYEK SERDAR , ÖVÜNÇ KENAN , KABAKÇI GIRAY , ÖZER NECLA , KES SIRRI
Published: December 2004

SADE, E., et al.: Assessment of Heart Rate Turbulence in the Acute Phase of Myocardial Infarction for Long‐Term Prognosis.
This study is designed to assess the value of heart rate turbulence (HRT) in the acute phase of MI for prediction of long‐term mortality risk. The study included 128 consecutive acute MI patients with 24‐hour Holter recordings to evaluate HRT (turbulence onset and slope), SDNN, mean RR interval, and ventricular premature beat frequency. LVEF was evaluated by two‐dimensional echocardiography. Data from 117 patients (mean age 58 ± 11 years) were available for further analysis. Twelve patients died during follow‐up (mean 312 ± 78 days). Although SDNN < 70 ms was the most powerful predictor of mortality among all presumed risk factors (hazard ratio 20 [95% CI 2.6–158]; P = 0.004) in univariate Cox regression analysis, in multivariate analysis LVEF ≤ 0.40 and turbulence slope ≤2.5 ms/RR interval were the only independent predictors of mortality (hazard ratio 6.9 [95% CI 1.8–26]; P = 0.006, hazard ratio 7.3 [95% CI 1.4–37]; P = 0.016, respectively). Addition of HRT parameters for LVEF increased remarkably the positive predictive value (60%) without any decrease in the negative predictive value (92%). Blunted HRT reaction within the first 24 hours of acute MI is an independent predictor of long‐term mortality. Furthermore, its predictive power is comparable and also additive to that of LVEF. (PACE 2003; 26[Pt. I]:544–550)
Regional Left Ventricle Mechanical Asynchrony in Patients with Heart Disease and Normal QRS Duration:
Authors: YU CHEUK‐MAN , YANG HUA , LAU CHU‐PAK , WANG QIONG , WANG SHELLEY , LAM LINDA , SANDERSON JOHN E.
Published: December 2004

YU, C.‐M., et al.: Regional Left Ventricle Mechanical Asynchrony in Patients with Heart Disease and Normal QRS Duration: Implications for Biventricular Pacing Therapy.
LV electromechanical delay results in asynchronized contraction. However, it is not known if the presence of cardiac diseases without QRS prolongation may result in inter‐ or intraventricular asynchrony. This study investigated the occurrence of systolic mechanical delay in different regions of the LV in patients with underlying heart diseases and normal QRS duration. Tissue Doppler imaging (TDI) was performed in 141 patients

(age 63.7 ± 11.5 years)

with underlying heart diseases (82% had ischemic heart disease) and 92 normal healthy volunteers

(age 63.9 ± 9.8 years)

based on the four‐basal and four‐mid‐segment model by apical views. Of these, 124 patients had normal QRS duration

(≤120 ms)

while 17 were prolonged due to LBBB or intraventricular conduction defect. Patients with normal QRS duration had significantly lower peak myocardial isovolumic contraction velocity

(IVCM)

, sustained systolic velocity

(SM)

, and prolonged time to peak

IVCM

and

SM

in almost all myocardial segments when compared to controls. The time to peak

IVCM

(basal lateral vs basal septal segment:

61.0 ± 29.4
vs 53.3 ± 24.1 ms, P < 0.005) andSM(basal lateral vs basal septal segment:174 ± 44vs154 ± 36 ms, P < 0.001) was further delayed in the LV free‐wall segments. Mechanical delay was also evident in the LV free‐wall segments in patients with preserved or impaired systolic function, in patients with or without previous myocardial infarction, and in patients with prolonged QRS duration. Patients with prolonged QRS had a higher prevalence of LV free‐wall delay of >50ms (47 vs 24%, chi‐square = 4.6, P < 0.05). In conclusion, the presence of cardiac diseases was characterized by LV global mechanical delay; and, intraventricular asynchronized contraction characterized mostly by further mechanical delay in the free‐wall region. These changes occur even in those with normal QRS duration. (PACE 2003; 26[Pt. I]:562–570)