Jacques Victor

Risk Factors Related to Infections of Implanted Pacemakers and Cardioverter-Defibrillators Results of a Large Prospective Study

Background— The Prospective Evaluation of Pacemaker Lead Endocarditis study is a multicenter, prospective survey of the incidence and risk factors of infectious complications after implantation of pacemakers and cardioverter-defibrillators. Methods and Results— Between January 1, 2000, and December 31, 2000, 6319 consecutive recipients of implantable systems were enrolled at 44 medical centers and followed up for 12 months. All infectious complications were recorded, and their occurrence was related to the baseline demographic, clinical, and procedural characteristics. Among 5866 pacing systems, 3789 included 2 and 117 had >2 leads; among 453 implantable cardioverter-defibrillators, 178 were dual-lead systems. A total of 4461 de novo implantations occurred and 1858 pulse generator or lead replacements. Reinterventions were performed before hospital discharge in 101 patients. Single- and multiple-variable logistic regression analyses were performed to identify risk factors; adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. At 12 months, device-related infections were reported in 42 patients (0.68%; 95% CI, 0.47 to 0.89). The occurrence of infection was positively correlated with fever within 24 hours before the implantation procedure (aOR, 5.83; 95% CI, 2.00 to 16.98), use of temporary pacing before the implantation procedure (aOR, 2.46; 95% CI, 1.09 to 5.13), and early reinterventions (aOR, 15.04; 95% CI, 6.7 to 33.73). Implantation of a new system (aOR, 0.46; 95% CI, 0.24 to 0.87) and antibiotic prophylaxis (aOR, 0.4; 95% CI, 0.18 to 0.86) were negatively correlated with risk of infection. Conclusions— This study identified several factors of risk of device infection and confirmed the efficacy of antibiotic prophylaxis in recipients of new or replacement pacemakers or implantable cardioverter-defibrillators.

Optimal right ventricular pacing site in chronically implanted patients: a prospective randomized crossover comparison of apical and outflow tract pacing.

OBJECTIVES To evaluate the long-term functional and hemodynamic effects of right ventricular outflow tract (RVOT) pacing by comparison with right ventricular apical (RVA) pacing. BACKGROUND Acute studies have suggested that RVOT pacing could significantly improve cardiac performance in comparison with RVA pacing but no data are available in chronically implanted patients. METHODS Sixteen patients with chronic atrial tachyarrhythmia and complete AV block were included. Left ventricular ejection fraction (LVEF) was > or =40% in ten and <40% in six. Patients were implanted with a standard DDDR pacemaker connected to two ventricular leads. A screw-in lead was placed at the RVOT and connected to the atrial port. A second lead was positioned at the RVA and connected to the ventricular port. Right ventricular outflow tract and RVA pacing was achieved by programming either the AAIR or the VVIR mode respectively. Four months later patients were randomized so as to undergo either RVOT or RVA pacing for three months according to a blind crossover protocol. Apart from the pacing mode, programming remained unchanged throughout the study. At the end of each period, NYHA class, LVEF, exercise time and maximal oxygen uptake were assessed. RESULTS No significant difference was observed between the two modes for all the parameters analyzed. These identical results were observed in all patients globally, in patients with LVEF > or =40% as in those with LVEF <40%. CONCLUSIONS Within the limits of this study, no symptomatic improvement or hemodynamic benefit was noted after three months of RVOT pacing, by comparison with RVA pacing.

Echocardiographic Assessment of the Interventricular Delay of Activation and Correlation to the QRS Width in Dilated Cardiomyopathy

ROULEAU, F., et al.: Echocardiographic Assessment of the Interventricular Delay of Activation and Correlation to the QRS Width in Dilated Cardiomyopathy. The aim of the study was to define criteria for left ventricular pacing in dilated cardiomyopathy (DCM) using an echocardiographic evaluation of interventricular electromechanical delay (IMD) and a correlation of IMD to QRS duration. Standard 12‐lead ECG and echocardiography with pulsed Doppler tissue imaging (DTI) were recorded in 35 DCM patients (mean age 58 ± 11 years) with QRS duration from narrow (80 ms) to broad (222 ms) patterns. The time for left ventricular activation was evaluated from the onset of QRS to the onset of aortic flow (Q‐Ao) by standard pulsed Doppler (SP) or to the onset of mitral annulus systolic wave (Q‐Mit) (DTI). The time for right ventricular activation was determined from the onset of QRS to the onset of pulmonary flow (Q‐Pulm) (SP) or to the onset of tricuspid annulus systolic wave (Q‐Tri) (DTI). (Q‐Ao)–(Q‐Pulm) and (Q‐Mit)–(Q‐Tri) determined IMD for each method, respectively. QRS width and IMD showed correlation coefficients of r = 0.86 ([Q‐Ao]‐[Q‐Pulm]) and r = 0.82 ([Q‐Mit]‐[Q‐Tri]) (P ≤ 0.001). Mean IMD of 77 ± 15 ms (SP) and 88 ± 26 ms (DTI) were noted for QRS width above 150 ms. Left ventricle delayed activation was positively correlated to QRS widening with both methods, (r = 0.90, [Q‐Ao]), (r = 0.83, [Q‐Mit]) (P ≤ 0.001). In conclusion, QRS duration is a good marker of an interventricular mechanical asynchrony. According to IMD correction, left ventricular pacing may be mainly proposed to symptomatic DCM patients with QRS duration > 150 ms.

Programming Optimal Atrioventricular Delay in Dual Chamber Pacing Using Peak Endocardial Acceleration: Comparison with a Standard Echocardiographic Procedure

DUPUIS, J.‐M., et al .: Programming Optimal Atrioventricular Delay in Dual Chamber Pacing Using Peak Endocardial Acceleration: Comparison with a Standard Echocardiographic Procedure. Optimization of programmed atrioventricular delay in dual chamber pacing is essential to the hemodynamic efficiency of the heart. Automatic AV delay optimization in an implanted pacemaker is highly desirable. Variations of peak endocardial acceleration (PEA) with AV delay at rest correlate well with echocardiography derived observations, particularly with end‐diastolic filling and mitral valve closure timings. This suggests the possibility of devising a procedure for the automatic determination of the optimal AV delay. The aim of this study was to compare a proposed algorithm for optimal AV delay determination with an accepted echocardiographic method. Fifteen patients with high degree AV block received BEST‐Living pacing systems. Automatic AV delay scans were performed at rest (60–300 ms in 20‐ms steps with 60 beats per step) in DDD at 90 ppm, while simultaneously recording cycle‐by‐cycle PEA values, which were averaged for each AV delay to obtain a PEA versus AV delay curve. Nonlinear regression analysis based on a Boltzmann sigmoid curve was performed, and the optimal AV delay (OAVD) was chosen as the sigmoid inflection point of the regression curve. The OAVD was also evaluated for each patient using the Ritter echocardiographic method. Good sigmoid fit was obtained in 13 of 15 patients. The mean OAVD obtained by the PEA sigmoid algorithm was 146.9 ± 32.1  ms , and the corresponding result obtained by echocardiography was 156.4 ± 34.3  ms (range 31.8–39.7 ms). Correlation analysis yielded r = 0.79, P = 0.0012. In conclusion, OAVD estimates obtained by PEA analysis during automatic AV delay scanning are consistent with those obtained by echocardiography. The proposed algorithm can be used for automatic OAVD determination in an implanted pacemaker pulse generator. (PACE 2003; 26:[Pt. II]:210–213)

Value of automatic processing and reliability of stored data in an implanted pacemaker: initial results in 59 patients.

Stored data in implantable pacemakers have rarely been used as a diagnostic tool because of the complexity. Our group bas developed software called AIDA, providing an automatic interpretation of data stored in memories of the Chorus (ELA medical) pacemaker. We com pared the results of AIDA analysis to surface ECG Holter interpretation in 59 patients (age 75 ± 9 years). In 33 cases, neither AIDA nor the Holter found any anomaly. Eleven patients demonstrated episodes of supraventricular tachycardia (SVT), confirmed by AIDA in ten patients; AIDA failure was due to nonsustained episodes of SVT not inducing mode switch. Loss of atrial sensing, pacemaker‐mediated tachycar dia, and ventricular extrasystoles were detected by AIDA in ten patients. Traditional Holter missed three cases. This initial study confirms that stored pacemaker data, automatically interpreted can provide reli able information over a 24‐hour period.

Comparison between isoproterenol and nitroglycerin sensitized head-upright tilt in patients with unexplained syncope and negative or positive passive head-up tilt response☆

It is unknown if the head-upright tilt test in patients who receive isoproterenol and nitroglycerin can identify different populations with vasovagal syncope. The aim of this study was to compare the positive or negative responses to passive tilt between isoproterenol- and nitroglycerin-sensitized upright tilt. Ninety-six patients referred for unexplained recurrent syncope underwent passive tilt (45 minutes at 70 degrees angle), which was then systematically followed, within the same session and in a random order, by a 20-minute tilt at a 70 degrees angle after administration of nitroglycerin (NTG-tilt) and 10-minute tilt at a 70 degrees angle with a continuous infusion of isoproterenol (ISO-tilt). NTG-tilt led to significantly more positive responses than passive tilt or ISO-tilt (55% vs 34% vs 42%, respectively). In the subgroup of patients with a positive response during passive tilt, the percentage of positive responses with NTG-tilt was significantly higher than with ISO-tilt (94% vs 67%). The agreement between NTG-tilt and ISO-tilt was very weak (Kappa coefficient 0.06). In the subgroup of patients with a negative response during passive tilt, the percentage of positive responses between NTG-tilt and ISO-tilt was similar (35% vs 29%). The agreement between NTG-tilt and ISO-tilt was good (Kappa coefficient 0.34). NTG-tilt led to a higher number of positive responses than ISO-tilt, especially when passive tilt outcome was positive. These 2 pharmacologic agents may identify 2 different subpopulations of patients because of their specific pharmacologic actions.

Fetal tachycardia: a role for amiodarone as first- or second-line therapy?

BACKGROUND Fetal tachycardias result in serious prenatal and postnatal morbidity and mortality. Intrauterine treatment can improve prognosis dramatically and the therapeutic protocol is well defined. Currently, amiodarone is used as third-line therapy and is reserved for refractory cases. AIMS Our aim was to review the management and outcome of fetal tachycardia, giving particular consideration to the efficacy and safety of amiodarone therapy. METHODS This was a retrospective study of 24 consecutive cases of sustained fetal tachycardia, treated mainly with digoxin and/or amiodarone administered by the transplacental route. RESULTS The 24 fetal tachycardias comprised 16 supraventricular tachycardias with 1:1 atrioventricular conduction, seven atrial flutters and one ventricular tachycardia. Seven fetuses were hydropic and eight experienced less severe cardiac failure. Digoxin monotherapy converted 5/12 non-hydropic fetuses and 0/2 hydropic fetuses, with one intrauterine death. Amiodarone monotherapy converted 5/5 fetuses, including two hydropic fetuses: one ventricular tachycardia, two atrial flutters and two supraventricular tachycardias. When administered with digoxin, amiodarone converted all but two fetuses (7/9). No deaths were associated with amiodarone, but there was moderate morbidity, with six transient elevations of thyroid stimulating hormone at birth, two of which required short-term thyroid hormonal substitution therapy. CONCLUSION Maternal oral amiodarone seems to be effective and relatively safe, even in hydropic fetuses. We suggest that this treatment could be used earlier than is currently advised.

Cerebral hemodynamics in carotid sinus syndrome and atrioventricular block

Carotid sinus syndrome (CSS) is a cause of syncope due to exaggerated baroreceptor-mediated cardioinhibitory/vasodepressive reflexes. We sought to determine if cerebral hemodynamics and regulation were specifically altered in these patients by comparison with pure asystole without vasodepression in patients with atrioventricular block (AVB). Mean blood flow velocity (transcranial Doppler sonography) and mean arterial blood pressure (Finapres) were recorded during cardioinhibition induced by carotid massage in patients with CSS (n = 14, 75 +/- SD 8 years) and asystole induced by temporary pacemaker inhibition in patients with complete AVB (n = 10, 69 +/- 11 years). Cerebrovascular resistance was estimated by the arterial pressure/cerebral flow velocity ratio, and dynamic cerebral autoregulatory responses were determined by the rate of regulation and autoregulatory index. Asystole and cardioinhibition each induced a decrease in arterial pressure (CSS 55 +/- 9% vs AVB 40 +/- 14%, p <0.05) and cerebral flow velocity (CSS 66 +/- 19% vs AVB 69 +/- 14%, p = NS), with an initial transient increase in cerebrovascular resistance (CSS 102 +/- 136% vs AVB 128 +/- 92%, p = NS) followed by a decrease (CSS 38 +/- 12%, AVB 29 +/- 13%, p = NS). The rate of regulation and autoregulatory index were higher with AVB (0.43 +/- 0.20 and 8.5 +/- 1.1 second(-1)) than CSS (0.20 +/- 0.12 and 4.8 +/- 1.3 second(-1), respectively, p <0.01 and p <0.001 vs AVB). During asystole and vasodepression, cerebral hypoperfusion in CSS is normally compensated for by cerebral autoregulation. The lower rate of regulation in CSS compared with AVB likely results from persistent peripheral vasodepression triggered by carotid massage.

Carotid Sinus Syndrome: Acute Hemodynamic Evaluation of a Dual Chamber Pacing Mode

Cardiac pacing is the treatment of choice in patients with carotid sinus syndrome (CSS), Three different pacing modes were tested in 20 patients (16 males, 4 females; mean age 75 ± 9 years) with documented symptomatic CSS, Three carotid sinus massages (CSM) were performed in each supine patient successively paced in random order in: DDI—the reference pacing mode; DDD—automatic mode conversion (DDD/AMC) allowing automatic switching from AAI to DDD when AV block occurs; DDD/AMC plus a trial acceleration (DDD/AMC + ace); and OOO (CSM without pacing) to determine whether the vasodepressive effect was still present 10 minutes after the preceding CSM. Intraarterial blood pressure was continuously monitored. Results were expressed as the value of the mean systolic BP at TO + 3 s + 6 s … TO + 30 s divided by the value of the mean systolic blood pressure prior to onset of CSM. The drop in arterial blood pressure was more severe in the DDI mode than in DDD/AMC (P < 0,001) and DDD/AMC + acc (P < 0.0001) in 20 patients. In the OOO mode, the drop in arterial blood pressure was most marked and greater than in the DDI mode (P < 0.0001). The average time between start of the CSM and onset of the drop in blood pressure was the same in the three dual chamber modes. We conclude that the DDD/AMC mode significantly improves the vasodepressor response to CSM compared to the DDI mode. There is a current trend favoring DDD/AMC + acc over DDD/AMC.

Haemodynamic response to peripheral venous congestion in patients with unexplained recurrent syncope.

In patients with recurrent unexplained syncope, exaggerated peripheral venous pooling and impaired circulatory adjustment is thought to contribute to the outcome of a head-up tilt (HUT) test. The present study investigated the role of leg volume changes during venous congestion in the haemodynamic response of patients with recurrent unexplained syncope and the ability to predict the outcome of a HUT test. Changes in calf volume (strain gauge plethysmography), heart rate and arterial blood pressure were recorded in 60 patients with history of unexplained syncope (without postural tachycardia symptom) during venous congestion provoked by pneumatic thigh cuffs while supine at rest and during the initial 10 min of a 45 min 70 degrees HUT test. Twenty-seven patients [age (mean+/-S.D.), 39+/-16 years] exhibited symptoms [HUT(+)] and 33 patients (45+/-14 years) were asymptomatic [HUT(-)]. During venous congestion, mean+/-S.E.M. calf volume increased in both groups [HUT(-), 4.5+/-0.2; HUT(+), 4.8+/-0.4 ml x 100 ml(-1), not significant), but significantly less during head-upright tilt [HUT(-), 3.3+/-0.2, P <0.01; HUT(+), 2.6+/-0.3 ml x 100 ml(-1), P <0.001] without differences between the groups. During venous congestion, arterial pressure increased significantly in asymptomatic HUT(-) patients, but not in the HUT(+) patients. Calf volume changes did not correlate with a symptomatic outcome to a 70 degrees HUT. The lack of exaggerated venous pooling during venous congestion and the inability of calf volume changes to predict a positive HUT suggest that excessive venous pooling does not contribute to the outcome of HUT. Attenuated changes in arterial pressure during venous congestion while supine suggest impaired adjustment of peripheral resistance to leg venous occlusion.