bluuebunny/crossref_metadata_2025 huggingface dataset:
Retransfusion of filtered shed blood in primary total hip and knee arthroplasty: a prospective randomized clinical trial
Authors: Moonen Adrianus F.C.M. , Knoors Nico T. , Van Os Johannes J. , Verburg Aart D. , Pilot Peter
Published: January 2007

BACKGROUND: Allogeneic blood transfusions are associated with a number of well‐recognized risks and complications. Postoperative retransfusion of filtered shed blood is an alternative to (reduce) allogeneic blood transfusion. The objectives of this study were to evaluate the clinical efficacy of retransfusion of filtered shed blood and to evaluate the complications, in particular febrile reactions.

STUDY DESIGN AND METHODS: In this clinical trial 160 patients undergoing primary total hip or knee replacement were randomly assigned to receive either a retransfusion system (Bellovac, AstraTech AB) or a regular drain (Abdovac, AstraTech AB). Patients with a preoperative hemoglobin (Hb) level of between 13.0 and 14.6 g per dL were included. The shed blood was returned 6 hours after operation. After surgery the anesthesiologist determined the transfusion trigger. When Hb level dropped below this trigger, an allogeneic blood transfusion was given. The following data were obtained: number of allogeneic blood transfusions, total volume of blood collected in the bag used for retransfusion, perioperative Hb levels, febrile reaction, and other complications.

RESULTS: In the control group 19 percent of the patients received at least one allogeneic blood transfusion. In the study group this percentage was 6 percent of the patients (p = 0.015). Comparing total knee and total hip arthroplasty (control vs. study) the percentages were, respectively, 16 percent versus 2 percent (p = 0.040) and 21 percent versus 11 percent (NS). On average 308 mL of filtered shed blood was retransfused in the study group. In the study group 18 percent of patients had febrile reactions compared to 20 percent in the control group.

CONCLUSION: Postoperative retransfusion of filtered shed blood is effective for decreasing allogeneic blood transfusions after total hip and knee arthroplasty. There was no relationship between retransfusions and postoperative febrile reactions.
Blood collection and transfusion in the United States in 2001
Authors: Sullivan Marian T. , Cotten Russell , Read Elizabeth J. , Wallace Edward L.
Published: January 2007

BACKGROUND: Collection, processing, and transfusion of blood and blood components in the United States in 2001 were measured and compared with prior years.

STUDY DESIGN AND METHODS: The survey was completed by 1443 blood centers and hospitals. Statistical procedures were used to verify the representativeness of the sample and to estimate national totals.

RESULTS: The total US blood supply in 2001 was 15,320,000 units (before testing), 10.4 percent greater than in 1999. It included 14,259,000 allogeneic units, 619,000 autologous units, and 273,000 red cell (RBC) units collected by apheresis. Transfusion of whole blood (WB) and RBCs increased by 12.2 percent to 13,898,000 units. Platelet (PLT) transfusions totaled 10,196,000 units, an increase of 12.6 percent in comparison with 1999. The use of single‐donor apheresis PLTs increased by 26.0 percent to 7,582,000 PLT concentrate equivalent units. The use of PLTs from WB (PLT concentrates) continued a downtrend, declining 13.9 percent to 2,614,000.

CONCLUSIONS: The margin between transfusion demand and the total allogeneic supply in 2001 was 1,162,000 units, 7.9 percent of supply. By comparison, the 1999 margin was 9.1 percent. The rate of blood collection per 1,000 donor‐eligible population in 2001 was 8.9 percent higher than in 1999, due largely to additional donations following the September terrorist attacks. During the same period, however, the rate of transfusion per 1,000 total US population increased by 9.9 percent to 50.0 units, the highest in 15 years of measurement. The steady increase in demand continues to challenge the US blood community.
Impact of demographic changes on the blood supply: Mecklenburg‐West Pomerania as a model region for Europe
Authors: Greinacher Andreus , Fendrich Konstanze , Alpen Ulf , Hoffmann Wolfgang
Published: January 2007

BACKGROUND: The population structure in most European countries is currently changing with a shift from younger to older age groups. This study analyzed how demography will determine future blood demand and supply in a well‐characterized region.

STUDY DESIGN AND METHODS: The population of the main catchment area of the University Hospital Greifswald (415,000 inhabitants) was projected to the year 2015 based on 1‐year age groups provided by the population registry, based on 2002 rates assuming stable death rates and migration patterns. Data on donors and recipients for the years 1996 through 2004 were extracted from the database of the Department of Transfusion Medicine.

RESULTS: Until 2015, the increase in the older population will result in an 11.8 to 13.9 percent increase of blood transfusions. Assuming constant motivation to donate blood as in 2004, the decrease in the younger population will cause a 27.5 to 32.6 percent decrease of blood donations until 2015.

CONCLUSION: The increased demand for blood coincides with a significant reduction in blood donations. From 2008 the shortfalls will grow to 32 to 35 percent of the total demand in 2015 in the area studied. The demographic trends will affect many regions in Europe similarly. Coordinated efforts will be required to prevent blood shortages based on these demographic trends in western societies.
A model to predict the improvement of automated blood culture bacterial detection by doubling platelet sample volume
Authors: Wagner Stephen J. , Eder Anne F.
Published: January 2007

BACKGROUND: Some transmissions of bacterial infection from platelet (PLT) transfusion have occurred since introduction of automated blood culturing of apheresis PLTs. The majority of these cases involved false‐negative culture results in which slow‐growing Staphylococcus organisms were implicated. This study analyses the projected benefit in detecting slow growing organisms by increasing sample volume from 4 to 8 mL.

STUDY DESIGN AND METHODS: Bacterial growth was modeled by varying the initial inoculum, doubling time, and lag time. The numbers of organisms present at a 24‐hour sampling time were calculated. Poisson analysis was used to determine the fraction of 4‐ or 8‐mL samples that could be detected because they contained organisms. For each inoculum, the percentage of improved detection by doubling sample volume was defined as delta, the difference between the percentage of detection of 8‐ and 4‐mL samples.

RESULTS: The maximum improvement in detection by doubling sample volume was 25 percent and did not depend on bacterial growth rate or lag time. As inocula increased toward 40 colony‐forming units per unit, delta decreased. As lag and doubling times increased, inocula corresponding to maximum delta increased and the width of the distribution curve broadened.

CONCLUSION: Doubling sample volume will not double the chance of detecting slow growing organisms, but instead is predicted to improve detection by 25 percent or less.
Autonomic Control in Patients Experiencing Atrial Fibrillation After Cardiac Surgery
Authors: BAUERNSCHMITT ROBERT , MALBERG HAGEN , WESSEL NIELS , BROCKMANN GERNOT , WILDHIRT STEPHEN M. , KOPP BURKHARD , KURTHS JÜRGEN , BRETTHAUER GEORG , LANGE RÜDIGER
Published: January 2007

Background: Atrial fibrillation (AF) occurs in 20–40% of patients after open heart surgery and leads to an increased morbidity and prolonged hospital stay. Earlier studies have demonstrated that depressed baroreflex function predicts mortality and major arrhythmic events in patients surviving myocardial infarction. Cardiac surgery per se leads to decreased baroreflex sensitivity (BRS) and heart rate variability (HRV). Hence, the present study was aimed at analyzing the impact of the cardiovascular autonomous system on the development of postsurgical AF.

Methods and Results: The study covered 51 patients who consecutively underwent aortic valve replacement, coronary artery bypass surgery, or combined procedures. Noninvasive blood pressure and ECG were recorded the day before and 24 hour after surgery. BRS, linear as well as nonlinear HRV parameters were calculated using established methods. Eighteen patients developed AF during the first postoperative week, while 33 remained in sinus rhythm (SR) throughout the observation period. Patients with postoperative (PostOp) AF exhibited a significantly reduced preoperative (PreOp) BRS in terms of bradycardic and tachycardic regulation (average delayed slope [ms/mmHg]: SR: PreOp: 9.83 ± 3.26, PostOp: 6.02 ± 2.29, Pre‐Post: P < 0.001; AF: PreOp: 7.59 ± 1.99, PostOp: 6.39 ± 3.67, Pre‐Post: P < 0.044; AF vs SR: PreOp: P < 0.01, PostOp: ns). In both groups, surgery caused a decrease of BRS and HRV. Analysis of nonlinear dynamics revealed a tendency toward decreased system complexity caused by the operation; this trend was significant in patients remaining in sinus rhythm.

Conclusions: Patients experiencing postoperative AF obviously suffer from an impaired BRS before surgery already. These findings may be used to guide prophylactic antiarrhythmic therapy.
Staged Circumferential and Ostial Pulmonary Vein Ablation for the Treatment of Paroxysmal Atrial Fibrillation
Authors: KATRITSIS DEMOSTHENES , GIAZITZOGLOU ELEFTHERIOS , KOROVESIS SOCRATES , KOURLABA GEORGIA , VORIDIS EUTYCHIOS , CAMM A. JOHN
Published: January 2007

Background: Comparisons between segmental ostial disconnection of the pulmonary veins (PV) and circumferential ablation have produced conflicting results in patients with paroxysmal atrial fibrillation (AF). The aim of this study was to evaluate a staged ablation procedure, every step of which was assessed by means of AF inducibility.

Methods: Twenty‐two patients with paroxysmal AF were subjected to three ablation stages during one session: (1) circumferential ablation around the PV ostia, (2) segmental ostial PV isolation, and (3) ablation of areas within the circumferential lines with fractionated electrograms or voltage >0.2 mV as well as linear ablation at the mitral isthmus and the left atrial roof. Endpoint of the procedure was noninducibility of AF at any stage.

Results: Average radiofrequency energy delivery, fluoroscopy, and procedure times were 43 ± 11 minutes, 40 ± 11 minutes, and 3.8 ± 0.5 hours, respectively. At 6‐months follow‐up, four patients experienced recurrence of AF (18%), whereas two additional patients (9%) had left atrial arrhythmias not registered before the procedure. Ninety‐five percent of the patients who did not have inducible AF (regardless of the stage of ablation at which noninducibility was achieved) were free of recurrent AF, as opposed to none of the patients in whom AF was inducible at the end of the procedure (log‐rank test, P < 0.001).

Conclusions: A staged ablation procedure combing circumferential and ostial PV ablation with AF noninducibilty as endpoint may result in high success rates without the need of prolonged ablation sessions in certain patients with paroxysmal atrial fibrillation.
Closed Loop Stimulation Improves Ejection Fraction in Pediatric Patients with Pacemaker and Ventricular Dysfunction
Authors: DRAGO FABRIZIO , SILVETTI MASSIMO S. , DE SANTIS ANTONELLA , FAZIO GIOVANNI , BIANCALANA GIANLUCA , GRUTTER GIORGIA , RINELLI GABRIELE
Published: January 2007

Background: The aim of this prospective study was to evaluate the effect of the closed loop stimulation (CLS) on the ejection fraction in pediatric patients, affected by complete atrioventricular block (CAVB) or CAVB and sinus node dysfunction (SND), with a previously implanted pacemaker (PM) and ventricular dysfunction. The role of electrical therapy in the treatment of pediatric patients with congenital atrioventricular (AV) blocks has been shown. Conventional right ventricular pacing seems to affect ventricular function. Up to now, the feasibility and the long‐term results of biventricular pacing in pediatric patients were not entirely clear.

Methods: In eight pediatric patients with a previously implanted single or dual chamber PM, ventricular dysfunction, and CAVB or SND and CAVB, a dual chamber PM INOS2+‐CLS (Biotronik GmbH, Berlin, Germany) was implanted. The effect of the physiological modulation of CLS pacing mode on the ejection fraction was evaluated by Echo‐Doppler examination. Measurements were performed before the substitution of the old PM and for up to 2 years of follow‐up.

Results: All patients showed correct electrical parameters at implantation and during follow‐up. The mean value of the ejection fraction measured before the replacement of the old PM was 36 ± 7%, while after 2 years it was 47 ± 1% (P < 0.003). No patient showed any worsening of the ejection fraction, while only one showed no improvement.

Conclusions: DDD‐CLS pacing seems to improve ventricular function in pediatric patients with CAVB and/SND in spite of the use of the apical right conventional stimulation.
Importance of Anterograde Visualization of the Coronary Venous Network by Selective Left Coronary Angiography Prior To Resynchronization
Authors: DELARCHE NICOLAS , BADER HUGUES , LASSERRE RAPHAEL , DERVAL NICOLAS , DEBEUGNY STEPHAN , DENARD MAIALIZ , ESTRADE GÉRARD
Published: January 2007

Background: Understanding of coronary anatomy is essential to the advancement of cardiac resynchronization therapy (CRT) techniques. We determined whether the difficulties associated with catheterization of the coronary sinus (CS) and its lateral branches could be overcome by a preliminary angiographical study of the coronary venous system carried out during a pre‐operative coronary angiography with examination of venous return.

Methods and Results: All patients were scheduled for an exploratory angiography procedure and indicated for CRT. Group A patients were implanted with a CRT device after a right arterial angiographical procedure while group B patients had a selective left angiogram including examination of venous return. Data analyzed in group B were: position of CS ostium, number and distribution of lateral branches, and ability to preselect a marginal vein suitable for catheterization. Subsequent device implantation was guided by these parameters. A total of 96 and 89 patients were included in groups A and B, respectively. Implantation success rates were not different (98% and 100%, respectively), but CS catheterization time was reduced in group B (6 minutes vs 4 minutes; P < 10−6) as well as total time required to position the left ventricular lead (25 minutes vs 15 minutes; P < 10−6), fluoroscopy exposure (7 minutes vs 5 minutes; P < 10−6), and volume of contrast medium required (45 mL vs 15 mL; P < 10−6).

Conclusion: A coronary angiographical study, including examination of the coronary venous return prior to implantation of a CRT device, can simplify the device implant and allows patient‐specific preselection of appropriate tools for the procedure.
Cardiac Resynchronization Therapy: A Review of Proarrhythmic and Antiarrhythmic Mechanisms
Authors: TURITTO GIOIA , EL‐SHERIF NABIL
Published: January 2007

Available evidence supports the hypothesis that cardiac resynchronization therapy (CRT) results in favorable structural as well as electrical remodeling. Electrical remodeling seems to be related, to a large extent, to structural remodeling, usually referred to as reverse remodeling of left ventricular (LV) dysfunction. This can lead to amelioration of the arrhythmogenic substrate associated with depressed LV systolic function and heart failure. However, a direct electrophysiological effect due to favorable remodeling of repolarization with reduction of the dispersion of repolarization cannot be ruled out. On the other hand, in a small subgroup of patients, CRT could increase the dispersion of repolarization and induce malignant ventricular tachyarrhythmias. Clinical trials have consistently shown improved outcome with CRT‐defibrillators (CRT‐D) and more trials have demonstrated the benefits of the defibrillator in the population with depressed LV function. However, some physicians argue that implanting the less expensive and less complicated CRT‐pacemaker (CRT‐P) may be appropriate in certain groups of patients. Before this position is accepted, it is imperative that criteria for the selection of this group of patients with presumably low risk for sudden arrhythmic death as well as the proarrhythmic effect of CRT be clearly defined.
The Resting Electrocardiogram in the Management of Patients with Congestive Heart Failure: Established Applications and New Insights
Authors: MADIAS JOHN E.
Published: January 2007

The resting electrocardiogram (ECG) furnishes essential information for the diagnosis, management, and prognostic evaluation of patients with congestive heart failure (CHF). Almost any ECG diagnostic entity may turn out to be useful in the care of patients with CHF, revealing the non‐specificity of the ECG in CHF. Nevertheless a number of CHF/ECG correlates have been proposed and found to be indispensable in clinical practice; they include, among others, the ECG diagnoses of myocardial ischemia and infarction, atrial fibrillation, left ventricular hypertrophy/dilatation, left bundle branch block and intraventricular conduction delays, left atrial abnormality, and QT‐interval prolongation. In addition to the above well‐known applications of the ECG for patients with CHF, a recently described association of peripheral edema (PERED), sometimes even imperceptible by physical examination, with attenuated ECG potentials, could extend further the diagnostic range of the clinician. These ECG voltage attenuations are of extracardiac mechanism, and impact the amplitude of QRS complexes, P‐waves, and T‐waves, occasionally resulting also in shortening of the QRS complex and QT interval duration. PERED alleviation, in response to therapy of CHF, reverses all above alterations. These fresh diagnostic insights have potential application in the follow‐up of patients with CHF, and in their selection for implantation of cardioverter/defibrillator and/or cardiac resynchronization systems. If sought, PERED‐induced ECG changes are abundantly present in the hospital and clinic environments; if their detection and monitoring are incorporated in the clinician's “routine,” considerable improvements in the care of patients with CHF may be realized.
Torsades de Pointes in a Patient with Kearns‐Sayre Syndrome: A Fortunate Finding
Authors: SUBBIAH RAJESH N. , KUCHAR DENNIS , BARON DAVID
Published: January 2007

We present a case of a 33‐year‐old woman with Kearns‐Sayre syndrome (KSS) who had a pacemaker implanted for complete heart block postpartum and was found to have torsades de pointes. KSS is a rare encephalomyopathy associated with varying levels of central nervous system involvement, typically resulting in progressive external opthalmoplegia and retinal degeneration. Onset of cardiac conduction disease can be insidious and is a strong predictor of sudden cardiac death. The mainstay of treatment has been the judicious implantation of pacemakers. However, as highlighted in this case, patients who have an underlying cardiomyopathy may be more appropriately treated with an implantable cardioverter defibrillator.
Detour Conduction Can Mimic Complete Conduction Block at the Cavo‐Tricuspid Isthmus
Authors: YAMADA TAKUMI , MURAKAMI YOSHIMASA , PLUMB VANCE J. , KAY G. NEAL
Published: January 2007

A 54‐year‐old man with typical atrial flutter underwent linear ablation at the cavo‐tricuspid isthmus. Though standard tricuspid annulus (TA) mapping and differential pacing suggested complete isthmus conduction block, electroanatomic mapping revealed that detoured conduction through a residual conduction gap around the inferior vena cava far from the TA mimicked complete conduction block. Though the double potential interval along the block line was not long enough to guarantee a complete line of block after eliminating the conduction gap, electroanatomic remapping accurately confirmed a complete block line, suggesting electroanatomic mapping may be the most reliable method to confirm complete isthmus conduction block.
Spinal Cord Stimulation for Refractory Angina in a Patient Implanted with a Cardioverter Defibrillator
Authors: FERRERO PAOLO , GRIMALDI ROBERTO , MASSA RICCARDO , CHIRIBIRI AMEDEO , DE LUCA ANNA , CASTELLANO MADDALENA , CARDANO PAOLA , TREVI GIAN PAOLO
Published: January 2007

Spinal cord stimulation is currently used to treat refractory angina. Some concerns may arise about the possible interaction concerning the spinal cord stimulator in patients already implanted with a pacemaker or a cardioverter defibrillator. We are going to describe the successful implantation of a spinal cord stimulator in a patient previously implanted with a cardioverter defibrillator.
Preclavicular Route Following Cephalic Venous Cutdown for Pacemaker or Defibrillator Lead Implantation
Authors: TRIGANO ALEXANDRE , D'IVERNOIS CHRISTOPHE , LEVY SAMUEL , HARTUNG OLIVIER , ALIMI YVES
Published: January 2007

Following cephalic venous cutdown, an unexpected preclavicular course was used in two cases for a pacemaker and a defibrillator lead implantation. This very rare anomaly was documented by cephalic venogram but did not cause any significant intraoperative difficulty during single lead implantation.
Maximum Ventricular Dyssynchrony Predicts Clinical Improvement and Reverse Remodeling during Cardiac Resynchronization Therapy
Authors: TADA HIROSHI , TOIDE HIROYUKI , OKANIWA HIROKI , HIGUCHI RUMI , NAKAJIMA TSUTOMU , UTSUGI RIKA , HASHIMOTO TOHRU , MIYAJI KOHEI , KASENO KENICHI , TADOKORO KAZUYOSHI , NAITO SHIGETO , NOGAMI AKIHIKO , OSHIMA SHIGERU , TANIGUCHI KOICHI
Published: January 2007

Background: Tissue synchronization imaging (TSI) and tissue tracking imaging (TTI) might facilitate the evaluation of ventricular dyssynchrony.

Methods: In 22 patients, TSI and TTI were performed before and <1 month after onset of cardiac resynchronization therapy (CRT). With TSI guidance, maximum left ventricular (LV) intraventricular conduction delay (IVCDmax) was the greatest difference in time‐to‐peak velocity between septum and lateral wall. IVCD between the basal septum and lateral wall (IVCDbase) was also measured. Using TTI, the mean peak myocardial displacement of the basal septal and lateral walls (PMDbase), and the temporal coefficient of variation of the PMD in six LV regions (CV‐PMDLV) were measured. The patients were divided into responders (whose LV end‐systolic volume decreased by ≥15% during a 27 ± 9 months follow‐up) and nonresponders.

Results: Before CRT, IVCDbase was similar in both groups, and remained unchanged within the 1st month of CRT in both groups. However, before CRT, IVCDmax was greater in responders than in nonresponders (P < 0.05), and decreased only in the responders during CRT (P < 0.05). No significant difference was observed in PMDbase or CV‐PMDLV between the two groups, before or during CRT.

Conclusions: TSI was useful to measure IVCDmax. A greater IVCDmax before CRT that decreased shortly after onset of CRT may predict long‐term clinical improvement in CRT recipients.
Estimation of the Optimal VV Delay by an IEGM‐Based Method in Cardiac Resynchronization Therapy
Authors: MIN XIAOYI , MEINE MATHIAS , BAKER JAMES H. , PIRES LUIS A. , TURK KYONG T. , HORN EVELYN M. , KOWAL ROBERT C. , PARIS MICHAEL , PARK EULJOON , FAIN ERIC S.
Published: January 2007

Determination of the optimal interventricular (VV) delay in cardiac resynchronization therapy currently relies on costly, time‐consuming echocardiographic (ECHO) methods. This study evaluated the performance of a new intracardiac electrogram (IEGM)‐based VV method compared to the aortic velocity time integral (AVTI) method of VV delay optimization. The study included two patient groups. Eleven patients enrolled by a single center in the Rhythm II ICD trial underwent prospective comparisons of the AVTI at the VV interval determined by the IEGM VV method versus the maximum AVTI at the echocardiographically determined optimal VV delay. In 61 patients enrolled in the RHYTHM VV trial, the same testing methods were compared retrospectively. In the prospective study, the maximum AVTI by the ECHO‐based method (24.3 ± 7.9 cm), was closely correlated with maximum AVTI by the IEGM‐based method (23.9 ± 7.9 cm; concordance correlation coefficient = 0.99; 95% confidence, lower limit of 98%. Likewise, in the retrospective analysis, the ECHO‐determined maximum AVTI (22.1 ± 8.2 cm) was similar to that determined by the IEGM‐based method (20.9 ± 8.3 cm; concordance correlation coefficient = 0.98; 95% confidence, lower limit of 97%).
Effects of Stimulation Site on Diastolic Function in Cardiac Resynchronization Therapy
Authors: DE COCK CAREL C. , VOS DICK H. S. , JESSURUN EMILE , ALLAART COR P. , VISSER CEES A.
Published: January 2007

Background: Cardiac resynchronization therapy (CRT) improves left ventricular (LV) systolic function and clinical status, and prolongs survival of patients suffering from heart failure. An optimal LV site selection is key with respect to improvements in systolic function, though whether a site‐specific effect on diastolic function exists is unclear. This study compared the effects of CRT on changes in systolic and diastolic function from 2 LV stimulation sites.

Methods: We studied 21 patients in New York Heart Association functional classes ≥III, and a LV ejection fraction <0.30 and QRS duration > 130 ms. CRT leads were placed in the right ventricle, right atrium, and coronary sinus tributaries. LV stimulation was applied from the postero‐lateral and antero‐lateral wall. A LV conductance catheter was used to measure LV systolic and diastolic function. Systolic responders had >10% changes in dP/dtmax, and diastolic responders <10% changes in τ during CRT versus baseline. Response was highly dependent on LV lead position for both diastolic and systolic function. Diastolic responders decreased from 29% to 10% of patients, and systolic responders from 76% to 48%, in the best versus the worst lead position, respectively. Improvements in diastolic function were less pronounced than in systolic function (relative change −14% vs +28%, P < 0.05). Overall, 45% were both systolic and diastolic responders, 17% were both systolic and diastolic nonresponders, and 38% had opposite responses.

Conclusions: Changes in systolic and diastolic function were both highly dependent on the LV stimulation site. Diastolic function was less influenced by CRT and a high proportion of patients had discordant results.
Effects of Cardiac Resynchronization Therapy on Diastolic Function: Evaluation by Radionuclide Angiography
Authors: BORIANI GIUSEPPE , VALZANIA CINZIA , FALLANI FRANCESCO , BIFFI MAURO , MARTIGNANI CRISTIAN , SAPORITO DAVIDE , ZIACCHI MATTEO , DIEMBERGER IGOR , GRECO CRISTIANO , BERTINI MATTEO , DOMENICHINI GIULIA , LEVORATO MAURIZIO , FRANCHI ROBERTO , BRANZI ANGELO
Published: January 2007

While the beneficial effects of cardiac resynchronization therapy (CRT) on left ventricular (LV) systolic function have been demonstrated, no information is available regarding its effects on LV diastolic function during exercise. Using radionuclide angiography, we prospectively evaluated the effects of CRT on diastolic function at rest and during exercise in 15 patients consecutively referred for CRT. All patients underwent equilibrium Tc99 radionuclide angiography with bicycle exercise performed (1) at baseline; (2) immediately after CRT implantation, in spontaneous rhythm and during CRT; and (3) after 3 months of biventricular stimulation. Diastolic function was assessed by measurements of peak filling rate (PFR). At baseline, activation of biventricular stimulation influenced PFR neither at rest (1.06 ± 0.34 vs 1.07 ± 0.50 mL/s during spontaneous rhythm, P = 0.9) nor during exercise (1.45 ± 0.62 vs 1.33 ± 0.48 mL/s, P = 0.3). At 3 months, improvements were observed in New York Heart Association functional class and systolic function. By contrast, no improvement in diastolic function was observed either at rest (PFR = 1.11 ± 0.45 vs 1.07 ± 0.50 mL/s in spontaneous rhythm at baseline, P = 0.6) or during exercise (1.23 ± 0.50 vs 1.33 ± 0.48 mL/s, P = 0.2). These observations indicate that the intermediate benefits conferred by CRT on LV systolic function at rest and during exercise were not accompanied by similar improvements in diastolic function.
Feasibility Of Temporary Biventricular Pacing In Patients With Reduced Left Ventricular Function After Coronary Artery Bypass Grafting
Authors: EBERHARDT FRANK , HANKE THORSTEN , HERINGLAKE MATHIAS , MASSALME MAXIMILIAN S. , BECHTEL MATTHIAS , MISFELD MARTIN , WIEGAND UWE K. H.
Published: January 2007

Background and Methods: Biventricular pacing improves hemodynamics after weaning from cardiopulmonary bypass in patients with severely reduced left ventricular (LV) function undergoing coronary artery bypass grafting (CABG). We examined the feasibility of temporary biventricular pacing for 96 hours postoperatively. Unipolar epicardial wires were placed on the roof of the right atrium (RA), the right ventricular (RV) outflow tract, and the LV free lateral wall and connected to an external pacing device in 51 patients (mean LV ejection fraction 35 ± 4%). Pacing and sensing thresholds, lead survival and incidence of pacemaker dysfunction were determined.

Results: Atrial and RV pacing thresholds increased significantly by the 4th postoperative day, from 1.6 ± 0.2 to 2.5 ± 0.3 V at 0.5 ms (P = 0.03) at the RA, 1.4 ± 0.3 V to 2.7 ± 0.4 mV (P = 0.01) at the RV, and 1.9 ± 0.6 V to 2.9 ± 0.7 mV (P = 0.3) at the LV, while sensing thresholds decreased from 2.0 ± 0.2 to 1.7 ± 0.2 mV (P = 0.18) at the RA, 7.2 ± 0.8 to 5.1 ± 0.7 mV (P = 0.05) at the RV, and 9.4 ± 1.3 to 5.5 ± 1.1 mV (P = 0.02) at the LV. The cumulative overall incidence of lead failure was 24% by the 4th postoperative day, and was similar at the RV and LV. We observed no ventricular proarrhythmia due to pacing or temporary pacemaker malfunction.

Conclusions: Biventricular pacing after CABG using a standard external pacing system was feasible and safe.
Relationship Between Global Myocardial Index and Automatic Left Ventricular Border Detection Pattern to Identify Biventricular Pacing Candidates
Authors: COZMA DRAGOS , POPESCU BOGDAN A. , LIGHEZAN DANIEL , LUCIAN PETRESCU , MORNOS CRISTIAN , LUCA CONSTANTIN T. , GINGHINĂ CARMEN , DRAGULESCU STEFAN‐IOSIF
Published: January 2007

Objective of the Study:
to evaluate the relation between global myocardial index (GMI) and the pattern of left ventricular (LV) volume curves variation, using automatic border detection (ABD), and their role in assessing LV asynchrony.

Methods:
We studied 52 patients (mean age = 55 ± 17 years) with dilated cardiomyopathy. QRS duration (QRSd) and GMI were measured. Currently accepted TDI and M‐mode parameters were used to indicate LV dyssynchrony. On‐line continuous LV volume changes were recorded using ABD. Ejection time (ET ABD) was measured from the ABD wave‐forms as time interval between maximal and minimal volume variation during LV electromechanical systole. We derived the ejection time index (ETiABD) as the ratio between ET ABD and RR interval (ETiABD = ET/RR).

Results:
31 patients had a QRSd >120 ms and 21 patients had a QRSd <120 ms. Ventricular dyssynchrony was observed in 39 patients (29 patients had a QRSd > 120 ms). GMI was significantly higher in patients with, than in patients without ventricular dyssynchrony (1.06 ± 0.18 vs 0.73 ± 0.13, P = 0.0001), while ETABD was significantly smaller (233 ± 39 ms vs 321 ± 28 ms, P = 0.0001). The corresponding difference for ETiABD was 26.9 ± 6.8% vs 6.3 ± 4%, P < 0.0001. By simple regression analysis an inverse linear correlation was observed between GMI and ETiABD (r2=–0.51, P < 0.0001). The pattern of ABD waveforms showed increased isovolumic contraction and relaxation times in patients with LV asynchrony, similar to the GMI pattern.

Conclusions:
Regional delays in ventricular activation cause uncoordinated and prolonged ventricular contractions, with lengthening of the isovolumic contraction and relaxation times and shortening of the time available for filling and ejection. GMI explores these parameters and together with ABD might be useful to identify patients with ventricular asynchrony.
Temporary Atrial Pacing in the Prevention of Postoperative Atrial Fibrillation
Authors: NETO VICENTE ÁVILA , COSTA ROBERTO , DA SILVA KÁTIA REGINA , MARTINS ANDRÉ LUIZ MENDES , ESCOBAR LUIZ FERNANDO , MOREIRA LUIZ FELIPE PINHO , COSTA REGINA VALÉRIA , SANTOS LETÍCIA BEZERRA , MELO RICARDO FERNANDES AZEVEDO
Published: January 2007

Background: Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting (CABG). Since its prevention with prophylactic drug therapy has limited success, alternative approaches are desirable. This study examined the efficacy of atrial or biatrial pacing, compared with no pacing, on the incidence of AF after isolated CABG.

Methods: From August 2002 to September 2004, 240 patients underwent CABG. After surgery, right and left atrial epicardial pacing wires were implanted for 72 hours of temporary pacing. Patients were randomly assigned to one of three groups: no pacing (control group), right atrial (RA), and biatrial (BiA) pacing. Cardiac rhythm was monitored continuously during intensive care, or daily on the ward. The primary endpoints of this study were an episode of AF occurring up to 72 hours after CABG and the risk factors correlated with this event.

Results: Atrial and BiA pacing significantly lowered the incidence (1.25% vs 25%, P=0.001) of AF episodes, and were both correlated (odd ratio 0.038; 95% confidence interval 0.005–0.29) with a decrease in rates of postoperative AF. Multivariable analysis identified older age (odd ratio 1.074; 95% confidence interval 1.024–1.12) and no pacing as independent risk factors of postoperative AF.

Conclusions: Temporary right atrial or biatrial pacing after CABG significantly decreased the postoperative incidence of AF. Multivariable analysis identified older age and no pacing as predictors of AF occurrence.
Ablation of Idiopathic Ventricular Tachycardia in Two Separate Regions of the Outflow Tract: Prevalence and Electrocardiographic Characteristics
Authors: KASENO KENICHI , TADA HIROSHI , ITO SACHIKO , TADOKORO KAZUYOSHI , HASHIMOTO TOHRU , MIYAJI KOHEI , NAITO SHIGETO , OSHIMA SHIGERU , NOGAMI AKIHIKO , TANIGUCHI KOICHI
Published: January 2007

Few studies have clarified the prevalence and characteristics of idiopathic outflow tachycardia (OT‐VT) with an altered QRS morphology after radiofrequency catheter ablation (RFCA), requiring additional RFCA applications at a different portion of the outflow tract (OT) to abolish the OT‐VT. Among 344 patients (97 VTs and 247 premature ventricular contractions), 12 (3.5%; VTs‐7, PVCs‐5; 6 women) had dynamic QRS morphology changes following the RFCA, requiring additional RFCA applications at a different portion to abolish the OT‐VT. In 8 of 12 patients (67%), this phenomenon occurred following RFCA at right (RVOT; n=7) or left ventricular (LVOT; n=1) endocardial sites of the OT: The second OT‐VT was consistently associated with an increase in the R‐wave amplitude in the inferior leads, and in five it was finally abolished by RFCA at the left sinus of Valsalva (LSV). Conversely, in four patients (33%), the second OT‐VT appeared after RFCA at the LSV: two required additional RFCA applications at the LVOT to abolish the second OT‐VT, and one at the RVOT, and all were associated with a decrease in the R‐wave amplitude in the inferior leads. This kind of dynamic QRS morphology change was often observed when RFCA was applied to either the first or second OT‐VT at a right or left ventricular endocardial site, with the other site being the LSV. A detailed continuous observation of the QRS morphology, especially of the R‐wave in the inferior leads, is important for identifying changes in the QRS morphology during RFCA.
Prevalence and Characteristics of Left Atrial Tachycardia Following Left Atrial Catheter Ablation
Authors: HASHIMOTO TORU , TADA HIROSHI , NAITO SHIGETO , MIYAJI KOHEI , YAMADA MINORU , TADOKORO KAZUYOSHI , KASENO KENICHI , OSHIMA SHIGERU , TANIGUCHI KOICHI
Published: January 2007

Background: Left atrial tachycardia (AT) is a complication of left atrial catheter ablation (LACA) of atrial fibrillation (AF). However, its prevalence and characteristics have not been sufficiently clarified.

Methods: We divided 121 patients who underwent LACA into 2 groups based on the results of AT occurrence after LACA (follow‐up period; 12 ± 7 months): an AT+ group and AT– group.

Results: New‐onset left AT occurred in 30 patients (25%) 31 ± 51 days after LACA. Among the 26 patients with an early onset of AT, 4 underwent a second ablation for AT, and 21 became free of AT within 6 months without a repeat ablation procedure. Among the 4 patients with a late onset of AT (>2 months after the LACA), the tachycardia remitted without a repeat ablation procedure in a single patient within 6 months. Among 71 patients who underwent LACA with additional ablation lines, 22 (31%) developed new‐onset left AT. Among 50 patients who underwent LACA alone, 8 (16%) developed new‐onset left AT (P = 0.02).

Conclusions: New‐onset left AT is a frequent complication of LACA for AF, especially in men and in patients with a low left ventricular ejection fraction. Early (<2 months) onset AT does not require a repeat ablation because it often represents a transient phenomenon and disappears spontaneously.
Left Atrial Catheter Ablation Promotes Vasoconstriction of the Right Coronary Artery
Authors: YAMASHITA EIJI , TADA HIROSHI , TADOKORO KAZUYOSHI , HASHIMOTO TOHRU , KASENO KENICHI , MIYAJI KOHEI , NAITO SHIGETO , OSHIMA SHIGERU , TANIGUCHI KOICHI
Published: January 2007

Background: Multiple cardiac ganglia are present in the left atrial (LA) region, and marked changes in autonomic nervous activity can occur after left atrial catheter ablation (CA) for atrial fibrillation (AF). Vasospastic angina involving the inferior wall of the left ventricle has been reported as a complication shortly after LACA.

Methods: We studied 20 patients with drug‐refractory AF who underwent LACA, performed to encircle the left‐ and right‐sided pulmonary veins, 1 to 2 cm from their ostia under fluoroscopic guidance. Quantitative coronary angiography was performed before and after LACA, and we analyzed the minimal lesion diameter (MLD) of the proximal segment of the coronary arteries, and the basal tone, the baseline percent constriction versus maximal dilation after nitroglycerin administration.

Results: No significant difference was observed in MLD or basal tone of the left coronary arteries after LACA. However, in the right coronary artery (RCA), the basal MLD was smaller (P < 0.01) and the basal tone was greater (P< 0.05) after than before LACA. No correlation was found between the baseline MLD or tone of the RCA and total amount of radiofrequency energy delivered or procedure duration. In 75% of RCA, the baseline MLD was smaller after than before LACA, which was significantly higher (P < 0.01) than observed in the left coronary arteries (38%).

Conclusion: Vasoconstriction was promoted in the RCA shortly after LACA, which may explain the variant angina reported after LACA.
Clinical Predictors of Appropriate Implantable‐Cardioverter Defibrillator Discharge
Authors: CATANZARO JOHN N. , MAKARYUS AMGAD N. , SISON CRISTINA , VAVASIS CHRISTOS , DONALDSON DAVID , BELDNER STUART , BOAL BERNARD , JADONATH RAM
Published: January 2007

Background: The implantable cardioverter‐defibrillator (ICD) is the mainstay of treatment for ventricular tachyarrhythmias due to its impact on mortality. ICD discharges may be appropriate or inappropriate, and identification of patients at risk for ICD discharge is essential. We sought to determine the predictors of appropriate ICD discharge.

Methods: We analyzed data from 591 ICD recipients (mean age 67.9 ± 13.0 years; 474 men; mean follow‐up 10.9 ± 13.8 months). The association between ICD discharges and multiple clinical variables, including age, gender, hypertension, diabetes, coronary artery bypass graft (CABG) surgery, syncope, atrial fibrillation (AF), prior coronary intervention, left ventricular ejection fraction (LVEF), left ventricular end diastolic dimension, left ventricular end systolic dimension (LVESD), and ambient drug therapy was examined.

Results: The rates of appropriate or inappropriate discharges, delivered to 155 patients, were 0.49 per follow‐up year (F/Y). The median time‐to‐first appropriate discharge was 3.4 years. Among the discharges delivered, 97(63%) were appropriate and 58(37%) were inappropriate. Risk factors associated with a trend toward earlier appropriate discharges included age ≤65 years, and diuretic and digitalis use. By multiple variable analysis, no history of CABG and an enlarged LVESD were independent predictors of earlier appropriate ICD discharge.

Conclusions: Patients who did not have CABG revascularization were 2.8‐fold more likely than those who underwent CABG, and patients with enlarged LVESD were 2.5‐fold more likely than those with normal LVESD to receive appropriate ICD discharges. These patients deserve special vigilance and management in order to prevent the occurrence of ventricular tachyarrhythmias triggering ICD discharges.
A Comparison of ICD Implantations in the United States Versus Italy
Authors: GREENBERG STEVEN M. , EPSTEIN ANDREW E. , DEERING THOMAS , GOLDMAN DANIEL S. , GHIDINA MARCO , NEASON CURTIS , PROCLEMER ALESSANDRO
Published: January 2007

Background: The benefits conferred by implantable cardioverter defibrillators (ICDs) have expanded to primary prevention. The advancements in ICD therapy (ACT) registry in the United States and the Italian ICD registry (IIR) examine changing trends in ICD implantation in their respective countries. Data from these registries may be useful for comparison of transcontinental differences in ICD utilization.

Methods: This study includes initial implantations in patients enrolled in ACT and IIR. A comparative analysis was performed for device indications based on primary or secondary prevention. Sub‐group analyses by device types (single, dual chamber, or cardiac resynchronization) were performed.

Results: This analysis included 4,547 primary implantations in ACT and 6,491 in IIR. The groups were similar with respect to age. There were 82% primary and 18% secondary prevention indications in ACT, versus 42% primary and 58% secondary prevention indications in IIR (P < 0.001). There was a significantly higher rate of dual chamber ICD implants in ACT than in IIR for both primary (35.7% vs 23.7%, P < 0.001) and secondary prevention (52.3% vs 36.9%, P < 0.001). Conversely, more CRT‐D were implanted in IIR than in ACT (primary prevention 46.5% vs 32.0%; secondary prevention 29.0% vs 13.0%, P < 0.001).

Conclusions: Significant differences were observed in the types of indications for ICDs between ACT and IIR. Device prescription differed significantly between countries. The specific reasons for differences in ICD implantation patterns in these two countries are unclear. These observations warrant further investigations to determine if these differences are associated with different qualities of life and clinical outcomes.
Left Atrial Remodeling: Assessment of Size and Shape to Detect Vulnerability to Atrial Fibrillation
Authors: COZMA DRAGOS , POPESCU BOGDAN A. , LIGHEZAN DAN , LUCIAN PETRESCU , MORNOS CRISTIAN , GINGHINA CARMEN , DRAGULESCU STEFAN‐IOSIF
Published: January 2007

Background: The ellipse formula often underestimates left atrial (LA) dilation. Complete echocardiographic analysis of LA shape in relation to electrical remodeling has not been performed.

Aim of the Study: To analyze the relation between LA shape/surface and vulnerability to atrial fibrillation (AF).

Methods: We studied 112 patients aged 43 ± 16 years, and referred for electrophysiological study. LA surface (LAS) was measured at end‐systole (maximal). Trapezoidal LA shape was defined if the transverse dimension was less than the basal dimension. Decremental index (DI) was calculated as the maximal percentage prolongation of interatrial conduction time during atrial extrastimulation. The LA was considered vulnerable if AF was inducible. DI >50%, repetitive atrial activity, and fragmented electrograms defined susceptibility to vulnerability.

Results: LAS ranged between 10.5 and 36.6 cm2; 77 patients had a trapezoidal LA. By simple regression analysis LAS correlated with DI (r2= 0.38, P = 0.0001). LAS predicted susceptibility to vulnerability better than vulnerability to AF (area under the ROC curve: 0.93 vs 0.81). The best cut‐off value for LAS as predictor of susceptibility to vulnerability was 19.5 cm2 (sensitivity: 89%; specificity: 90.5%; positive predictive value: 93.4%; negative predictive value: 84.4%). Using LAS >25 cm2 as a cut‐off value, LA vulnerability to AF was detected with a sensitivity of 56.2% and a specificity of 95% (positive predictive value: 81.8%; negative predictive value: 83.3%). LA shape was trapezoidal in 72% patients with LAS >25 cm2 and in 30% patients with LAS <19.5 cm2 (P < 0.0001).

Conclusions: LA dilation and electrical remodeling are related. Progressive LA dilation is accompanied by shape remodeling. Appropriate characterization of LA remodeling should therefore include LAS measurement and LA shape assessment.
G‐CSF‐Induced Mobilization of CD34+ Progenitor Cells and Proarrhythmic Effects in Patients with Severe Coronary Artery Disease
Authors: WOLFRAM OLIVER , JENTSCH‐ULLRICH KATHLEEN , WAGNER ANDREA , HAMMWÖHNER MATTHIAS , STEINKE RAINER , FRANKE ASTRID , ZUPAN IGOR , KLEIN HELMUT U. , GOETTE ANDREAS
Published: January 2007

Aim: Granulocyte colony stimulating factor (G‐CSF) therapy has been reported to be proarrhythmic. The in vivo mobilization of endothelial progenitor cells (EPCs) and the possible proarrhythmic effects in patients with severe coronary artery disease (CAD) and inducible ischemia have not been described.

Methods: We treated 8 patients (mean age = 69 ± 10) suffering from severe CAD and angina pectoris (CCS 3 ± 0.5) despite optimal medical therapy with subcutaneous G‐CSF over 7 days to mobilize EPCs (CD34+, CD117+). ECG monitoring was performed throughout the treatment period. A 24‐hour ECG was recorded before and after G‐CSF application. Mobilization of EPCs was monitored by fluorescent activated cell sorter (FACS‐Calibur®, Becton‐Dickinson, Franklin Lakes, NJ, USA) analysis. Other medications remained unchanged.

Results: G‐CSF therapy significantly increased peripheral leukocyte count from 7.45 ± 2.4 to a peak of 42.2 ± 10.9 × 103/μL with a parallel rise in CD34+ EPCs from 4.35 ± 1.94 to 33.0 ± 22.8/μL. The percentage of CD34+/CD117+ cells changed from 0.32 ± 0.25 to 0.24 ± 0.28% (day of discharge, P = ns). During continuous ECG monitoring, no significant bradycardia, tachycardia, or changes in conduction were observed. Holter data collected after 7 days of G‐CSF therapy showed no significant differences from baseline. A linear correlation (r = 0.76) was observed for the absolute values of ΔP wave duration and ΔCD34+ concentration on day 2 compared to follow‐up at 142 ± 33 days, though it did not reach statistical significance (P = 0.29).

Conclusion: This is the first study showing that mobilization of CD34+ EPCs is safe in patients with severe CAD. The accompanying leukocytosis did not appear proarrhythmic. Changes in P wave duration might be attributable to G‐CSF therapy.