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Conduction Disturbances (conduction + disturbance)
Selected AbstractsPermanent Pacemaker Implantation Following Cardiac Surgery: Indications and Long-Term Follow-UpPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2009OFER MERIN M.D. Background: Conduction disturbances requiring permanent pacemaker implantation after heart surgery occur in about 1.5% of patients. Early pacemaker implantation may reduce morbidity and postoperative hospital stay. We reviewed our experience with patients undergoing surgery to try and identify predictors for pacemaker requirements and patients who will remain pacemaker dependent. Methods: We performed a retrospective review of 4,999 patients undergoing surgery between the years 1993 and 2005. Patient age was 64 ± 12 years, and 71% were males. Coronary bypass was performed in 4,071 (81%), aortic valve replacement in 675 (14%), and mitral valve replacement in 968 (18%) patients. Results: Seventy-two patients (1.4%) required implantation of a permanent pacemaker after surgery. Indications for pacemaker implantation included complete atrioventricular block in 59, symptomatic bradycardia/slow atrial fibrillation in nine, second-degree atrioventricular block in two, and other conduction disturbances in two patients. Predictors for pacemaker requirement by multivariate analysis were left bundle branch block and aortic valve replacement (P < 0.001). Late follow-up was available in 58 patients, at 72 ± 32 months. Thirty-seven (63%) were pacemaker dependent. Predictors for late pacemaker dependency were third-degree atrioventricular block after surgery and preoperative left bundle branch block (P < 0.001). Conclusions: Patients at high risk for pacemaker implantation after heart surgery include those with preexisting conduction disturbances, and those undergoing aortic valve replacement. Of those receiving a pacemaker, about one-third will recover at late follow-up. For patients in the high-risk group who are pacemaker dependent after surgery, we recommend implanting a permanent pacemaker at 5 days after surgery, thus enabling early mobilization and early discharge. [source] Hereditary neuropathy with liability to pressure palsies associated with central nervous system myelin lesionsEUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2001J. Dac Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disorder most commonly caused by a 1.5-Mb deletion in chromosome 17p11.2 which contains the peripheral myelin protein-22 (PMP22) gene. Mutations resulting in functional loss of one PMP22 gene copy are less frequent. We present a 51-year-old patient with a l.5-Mb deletion in chromosome 17p11.2 who exhibited signs of peripheral as well as central nervous system lesions. He gave a history of recurrent episodes of limb numbness and weakness with spontaneous but incomplete recovery since age 20. His father and two brothers had similar symptoms. Neurological examination revealed signs of multiple mononeuropathy associated with frontal lobe, corticospinal tract and cerebellar dysfunction, as well as signs of initial cognitive impairment. Electrophysiological investigations showed a demyelinating peripheral nerve disease with multiple conduction blocks and conduction disturbances in both optic nerves. Magnetic resonance imaging of the brain revealed multiple subcortical and periventricular foci of myelin lesions. The association of central and peripheral nervous system lesions in this patient indicates a possible role of PMP22 not only in peripheral but also in central nervous system myelin structure. [source] Connexin40-Deficient Mice Exhibit Atrioventricular Nodal and Infra-Hisian Conduction AbnormalitiesJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2000BRIAN A. VANDERBRINK B.S. AV Nodal and Infra-Hisian Conduction in Cx40 Mice. Introduction: Previous electrophysiologic investigations have described AV conduction disturbances in connexin4(Cx40)-deficient mice. Because expression or(Cx40 occurs predominantly in the atria and His-Purkinje system of the mouse heart, the AV conduction disturbances were thought to be secondary to disruption in His-Pnrkinje function. However, the lack of a His-bundle electrogram recording in the mouse has limited further investigation of the importance of Cx40. Using a novel technique to record His-bundle recordings in Cx40-deficient mice, we define the physiologic importance of defciencies in Cx40. Methods and Results: Ten Cx40 -/- mice and 11 Cx40+/+ controls underwent a blinded, in vivo, closed chest electrophysiology study at 9 to 12 weeks of age. In the Cx40+/+ mice, the PR interval was significantly longer compared with Cx40+/+ mice (44.6 ± 6.4 msec vs 36.0 ± 4.1 msec, P = 0.002). Not only the HV interval (14.0 ± 3.0 msec vs 10.4 ± 1.2 msec, P = 0.003) but also the AH interval (33.2 ± 4.8 msec vs 27.1 ± 3.7 msec, P = 0.006), AV Wenckebach cycle lengths, and AV nodal effective and functional refractory periods were prolonged in Cx40 -/- compared with Cx40+/+ mice. Conclusion: Cx40-deficient mice exhibit significant delay not only in infra-Hisian conduction, as would be expected from the expression of Cx40 in the His-Purkinje system but also in the electrophysiologic parameters that reflect AV nodal conduction. Our data suggest a significant role of Cx40 in atrionodal conduction and/or in proximal His-bundle conduction, [source] Predictors of Complete Heart Block After Alcohol Septal Ablation for Hypertrophic Cardiomyopathy and the Timing of Pacemaker ImplantationJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2007F.R.A.C.P., SEIFEDDIN S. EL-JACK M.B.B.S. Catheter-based alcohol septal ablation has recently been introduced for the treatment of left ventricular outflow tract obstruction in hypertrophic obstructive cardiomyopathy. It is associated with various conduction disturbances and may lead to transient or persistent complete heart block (CHB). Electrocardiographic (ECG) changes and predictors of developing CHB and the timing of permanent pacemaker implantation have been variable among the different studies. Among 50 patients studied, we found that a new right bundle branch pattern was the most common new ECG change after septal ablation and that baseline left bundle branch block was strongly associated with the development of CHB (P = 0.004); 9 patients (18%) required permanent pacemaker implantation of whom 7 (78%) remained pacemaker dependent at 14 days with no delayed recovery of atrioventricular conduction. This favors an early pacemaker implantation strategy. [source] Heart Rate Turbulence Impairment and Ventricular Arrhythmias in Patients with Systemic SclerosisPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2010PIOTR BIENIAS M.D., Ph.D. Background:,Arrhythmias, conduction disturbances, and cardiac autonomic nervous system dysfunction are the most frequent cardiovascular complications in systemic sclerosis (scleroderma). The aim of the study was to assess heart rate turbulence (HRT) in systemic sclerosis patients and to identify the relationship between HRT and occurrence of arrhythmias. Methods:,Forty-five patients with scleroderma (aged 54.6 ± 14.7 years) and 30 healthy sex- and age-matched subjects were examined. In addition to routine studies, 24-hour Holter monitoring with assessment of HRT was performed. Results:,As compared to controls, HRT was significantly impaired in systemic sclerosis patients. Abnormal HRT defined as turbulence onset (TO) ,0.0% and/or turbulence slope (TS) ,2.5 ms/RR (ms/RR interval) was found in 19 (42%) scleroderma patients and in no members of the control group. Serious ventricular arrhythmias Lown class IV (VA-LownIV), for example, couplets and/or nonsustained ventricular tachycardias, were observed in 16 (36%) scleroderma patients. The median value of TS was significantly lower in systemic sclerosis patients with VA-LownIV than in patients without VA-LownIV (3.68 vs 7.00 ms/RR, P = 0.02). The area under curve of ROC analysis for prediction of VA-LownIV was 0.72 (95% confidence interval [CI] 0.56,0.87) and revealed that TS <9.0 ms/RR was associated with VA-Lown IV occurrence, with sensitivity of 93.7% and specificity of 44.8%. Univariate and multivariate analyses confirmed that lower values of TS were associated with VA-LownIV occurrence (odds ratio 1.52, 95% CI 1.09,2.12, P = 0.01). Conclusions:,Patients with systemic sclerosis are characterized by significant HRT impairment. Assessment of HRT and especially TS is useful in the identification of patients at risk for ventricular arrhythmias. (PACE 2010; 920,928) [source] Permanent Pacemaker Implantation Following Cardiac Surgery: Indications and Long-Term Follow-UpPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2009OFER MERIN M.D. Background: Conduction disturbances requiring permanent pacemaker implantation after heart surgery occur in about 1.5% of patients. Early pacemaker implantation may reduce morbidity and postoperative hospital stay. We reviewed our experience with patients undergoing surgery to try and identify predictors for pacemaker requirements and patients who will remain pacemaker dependent. Methods: We performed a retrospective review of 4,999 patients undergoing surgery between the years 1993 and 2005. Patient age was 64 ± 12 years, and 71% were males. Coronary bypass was performed in 4,071 (81%), aortic valve replacement in 675 (14%), and mitral valve replacement in 968 (18%) patients. Results: Seventy-two patients (1.4%) required implantation of a permanent pacemaker after surgery. Indications for pacemaker implantation included complete atrioventricular block in 59, symptomatic bradycardia/slow atrial fibrillation in nine, second-degree atrioventricular block in two, and other conduction disturbances in two patients. Predictors for pacemaker requirement by multivariate analysis were left bundle branch block and aortic valve replacement (P < 0.001). Late follow-up was available in 58 patients, at 72 ± 32 months. Thirty-seven (63%) were pacemaker dependent. Predictors for late pacemaker dependency were third-degree atrioventricular block after surgery and preoperative left bundle branch block (P < 0.001). Conclusions: Patients at high risk for pacemaker implantation after heart surgery include those with preexisting conduction disturbances, and those undergoing aortic valve replacement. Of those receiving a pacemaker, about one-third will recover at late follow-up. For patients in the high-risk group who are pacemaker dependent after surgery, we recommend implanting a permanent pacemaker at 5 days after surgery, thus enabling early mobilization and early discharge. [source] P Wave Duration and Morphology Predict Atrial Fibrillation Recurrence in Patients with Sinus Node Dysfunction and Atrial-Based PacemakerPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2002ANTONIO DE SISTI DE SISTI, A., et al.: P Wave Duration and Morphology Predict Atrial Fibrillation Recurrence in Patients with Sinus Node Dysfunction and Atrial-Based Pacemaker. P wave duration and morphology have never been systematically evaluated as markers of AF in patients with a conventional indication to pacing. This study correlated sinus P wave duration and morphology and the incidence of AF in patients with sinus node dysfunction (SND), previous history of AF before implant, and atrial-based pacemaker. Included were 140 patients (86 men, 54 women; mean age 71.8 ± 10.4 years) with recurrent paroxysmal AF and who received a DDD (128 patients) or AAI (12 patients) pacemaker for SND. Forty-nine patients had structural heart disease. Sinus P wave duration and morphology was evaluated in leads II, III. Twenty-two patients had an abnormal P wave morphology, diphasic (+/-) in 5 and notched (+/+) in 17. The basic pacemaker rate was programmed between 60 and 70 beats/min. Rate responsive function was activated in 65 patients. During a follow-up of 27.6 ± 17.8 months, AF was documented in 87 patients. Forty-four patients developed permanent AF, following at least one episode of paroxysmal AF in 26 cases. Statistical analysis used Cox model regression. Univariate predictors of AF (P < 0.10) were drugs (mean: 2 ± 1.4) and DC shock before pacing (16/140 patients), P wave duration (mean 112.5 ± 24.6 ms), basic pacemaker rate (mean 68 ± 5 beats/min), and drugs in the follow-up (mean 1.2 ± 0.94). Multivariate analysis showed that P wave duration (b = 0.013, s.e. = 0.004; P = 0.003), and drugs before pacing (b = 0.2; s.e.= 0.08; P < 0.01) resulted in a significant independent predictor of AF. Actuarial incidence of patients free of AF at 30 months was 35%: 56% in patients with a P wave < 120 ms, and 13% in those with P wave , 120 ms (P < 0.01 by Score test). Univariate predictors of permanent AF were drugs and DC shock before pacing, left atrial size (mean 39 ± 6 mm), P wave duration, abnormal P wave morphology (22/140 patients), and drugs in the follow-up. Multivariate analysis showed that P wave morphology was the most important predictor of permanent AF (b = - 0.56, s.e.= 0.2; P = 0.008). Incidence of patients free of permanent AF at 30 months was 69%: 74% in patients with normal P wave, compared to 28% in the case of abnormal P wave morphology (P < 0.01). P wave duration and morphology are good markers of postpacing AF recurrence in patients with SND and an atrial-based pacemaker. This observation suggests that intra- and interatrial conduction disturbances be extensively evaluated before implantation, and the indication for atrial resynchronization procedures be reevaluated. [source] Electrophysiologicai Characteristics of the Atrium in Sinus Node Dysfunction With and Without Postpacing Atrial FihriliationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2000ANTONIO DE SISTI DE SISTI, A., ET AL.: Electrophysiologicai Characteristics of the Atrium in Sinus Node Dysfunction With and Without Postpacing Atrial Fibrillation . In patients with sinus node dysfunction (SND) with or without associated paroxysmal atrial fibrillation (AF), the effectiveness of atrial pacing in reducing the incidence of AF is not definitive. In addition, despite several studies involving large populations of implanted patients, little attention has been paid to the electrophysioiogicai (EP) atrial substrate and the effect of permanent atrial pacing. The aim of this study is to correlate EP data and the risk of AF after DDD device implantation. We reviewed FP data of 38 consecutive patients with SND. mean age 70 ± 8 years, who were investigated free of antiarrhythmic treatment, for the evaluation of the atrial substrate. We also considered as control group 25 subjects, mean age 63 ± 14 years, referred to our EP laboratory for unexplained syncope or various atrioventricular disturbances. Following pharmacological washout and at a drive cycle length of 600 ms. effective and functional refractory periods (ERP, FRP), Sl-Al and S2-A2 latency, Al and A2 conduction duration, and latent vulnerability index (EHP/A2) were measured. AF induction was tested with up to three extrastimuli at paced cycle lengths of 600 and 400 ms in 20 patients. Induction of sustained AF (> 30 seconds) was considered as the endpoint. P wave duration on the surface ECG in lead II/Vl was also measured. DDD pacing mode was chosen in all patients with the minimal atrial rate programmed between 60 and 75 beats/min (mean 64 ± 4 beats/min). After implantation, the patients were followed-up for 29 ± 17 months and clinically documented occurrence of AF was determined. When comparing patients with SND and subjects of the control group, we did not find any significant statistical differences in terms of ERP (237 ± 33 vs 250 ± 29 ms), FRP (276 ± 30 vs 280 ± 32 ms) and Sl-Al (39 ± 16 vs 33 ± 11 ms) and S2-A2 latency (69 ± 24 vs 63 ± 25 ms). In contrast, we observed significant differences regarding Al (55 ± 19 vs 39 ± 13 ms; P < 0.001), A2 (95 ± 34 vs 57 ± 18 ms; P < 0.001) and P wave duration (104 ± 18 vs 94 ± 15 ms; P < 0.05), and ERP/A2 (2.8 ± 1.2 vs 4.8 ± 1.6; P < 0.001). When comparing patients with (n = 11) or without (n =27) postpacing AF occurrence, we did not find any difference with reference to ERP, FRP. Sl-Al, S2-A2, Al duration, or follow-up duration. In patients with postpacing AF occurrence, A2 was longer (116 ± 41 vs 87 ± 27 ms; P < 0.01), FRP/A2 lower (2.1 ± 0.4 vs 3.1 ± 1.4; P < 0.05), P wave more prolonged (116 ± 22 vs 99 ± 14 ms; P < 0.01), and preexisting AF history predominant (6/11 vs 5/27 patients; P < 0.05). No difference was observed between patients with (n = 8) and without (n = 12) AF induction during the EP study. In patients with SND, the atrial refractoriness appears normal and the most important abnormality concerns conduction slowing disturbances. Persistence of AF despite pacing stresses the importance of mechanisms responsible for AF not entirely brady-dependent. In this setting, more prolonged atrial conduction disturbances, responsible for a low vulnerability index, and a preexisting history of AF enable us to identify a high risk patient group for AF in the follow-up. sinus node dysfunction, atrial fibrillation, electrophysiologicai study, atrial pacing [source] | ||||||||||