bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heart Rate Variability Before Ventricular Arrhythmias in Patients with Coronary Artery Disease and an Implantable Cardioverter Defibrillator
Authors: Copie Xavier , Lamaison Dominique , Salvador Michelle , Sadoul Nicolas , Costa Antoine Da , Fauchier Laurent , Legal François , Heuzey Jean‐Yves Le ,   the VALID Investigators
Published: July 2003

Background: Changes in autonomic regulation of the heart may be responsible for the occurrence of arrhythmias. Although a decrease in 24‐hour heart rate variability is a strong predictor of subsequent arrhythmias in patients with heart disease, many questions remain unanswered concerning changes in heart rate and heart rate variability in the minutes or hours preceding an arrhythmia. The aim of our study was to analyze changes in heart rate and heart rate variability occurring during the 90 minutes preceding an arrhythmia, in patients with coronary heart disease and an implantable defibrillator. Materials and Methods: Thirty‐eight patients, with a total of 93 episodes of ventricular arrhythmia, were included in the study. Heart rate and heart rate variability were measured in three 30‐minute and five 2‐minute periods preceding the arrhythmia. Heart rate variability was assessed using measurements of Poincaré plots. Results: The results show a gradual increase in heart rate before the arrhythmia, from 73 ± 13/min, to 75 ± 14/min, and finally 78 ± 15/min in the 90 minutes preceding the arrhythmia (P < 0.05). Conclusion: Measurements of Poincaré plots showed a significant increase in their length and no significant change in their width. These results suggest that sympathetic activation is the predominant change in autonomic nervous system before a ventricular arrhythmia in patients with coronary heart disease. This change may occur as early as one hour and a half before the arrhythmia.
Diagnostic Value of aVL Derivation for Right Ventricular Involvement in Patients with Acute Inferior Myocardial Infarction
Authors: Turhan Hasan , Yilmaz M. Birhan , Yetkin Ertan , Atak Ramazan , Biyikoglu S. Funda , Senen Kubilay , Ileri Mehmet , Cehreli Sengul , Korkmaz Sule , Kutuk Emine 
Published: July 2003

Background: Right ventricular (RV) involvement is associated with increased morbidity and mortality in patients with acute inferior myocardial infarction (MI). Although electrocardiography is probably the most useful, simple, and objective tool for the diagnosis of acute MI, there are no well‐defined criteria in the standard 12‐lead electrocardiogram to properly identify RV involvement in patients with acute inferior MI. Our objective was to evaluate the value of ST‐segment depression in lead aVL in diagnosing RV involvement in patients with acute inferior MI. Materials and Methods: Sixty‐seven patients, hospitalized with acute inferior myocardial infarction, were included in this study. The diagnosis of acute inferior myocardial infarction was based on the clinical history, characteristic enzyme pattern of CK‐MB values, and the appearance of ST‐segment elevation ≥ 1 mm in at least two of the leads (leads II, III, aVF). RV infarction was defined by ST‐segment elevation ≥ 1mm in lead V4R. ST‐segment depression in lead aVL that is more than 1 mm was accepted as a diagnostic criterion for RV involvement in patients with acute inferior MI. Results: Thirty‐one patients had >1 mm ST‐segment depression and 28 of them had right ventricular infarction according to lead V4R. Thirthy‐six patients showed ≤1 mm ST‐segment depression indicating no right ventricular involvement but four of them also had right ventricular infarction according to V4R. Conclusion: More than 1 mm ST‐segment depression in lead aVL was found to have high sensitivity (87%), specificity (91%), high positive and negative predictive value (90%, 88%, respectively), and high diagnostic accuracy (89%) in diagnosing RV involvement in patients with acute inferior MI. Therefore, by using a simple 12‐lead electrocardiographic sign, ST‐segment depression >1 mm in lead aVL, obtained on admission, it is possible to identify RV involvement in patients with acute inferior MI.
Does Impaired Left Ventricular Relaxation Affect P Wave Dispersion in Patients with Hypertension?
Authors: Dogan Abdullah , Mehmet Ozaydin , Cem Nazli , Ahmet Altinbas , Omer Gedikli , Ozan Kinay , Oktay Ergene 
Published: July 2003

Objective: P wave dispersion (PD) is considered to reflect the heterogeneous conduction in atria. We investigated whether there was a correlation between the left ventricular (LV) relaxation and PD. Method and Results: Fifty‐three hypertensive patients ≤60 years old were divided into two groups: Group A, 27 patients, aged 54 ± 5 years with the impaired LV relaxation and Group B, 26 patients, aged 51 ± 8 years with normal LV relaxation. The P wave durations were measured in all 12 leads of ECG and PD was defined as the difference between maximum and minimum P wave duration (Pmax−Pmin). Mitral inflow velocities (E and A), E deceleration time (DT), isovolumic relaxation time (IVRT), left atrial and ventricular diameters, and wall thickness of LV were obtained by echocardiography. Clinical characteristics of both groups were comparable. The wall thickness of LV, Pmax, and left atrial dimension were not different in both groups. A velocity was higher (P < 0.001), but E velocity (P = 0.03) and E/A ratio (P < 0.001) were lower in group A than in group B. IVRT and DT were also significantly longer in group A. PD was significantly higher in group A compared to group B (51 ± 9 vs 41 ± 11 ms, P = 0.01). This difference resulted from the Pmin (61 ± 10 vs 67 ± 9 ms, P = 0.03, respectively). Multivariate analysis revealed a significant correlation between PD and A velocity (r = 0.46, P = 0.01), E/A ratio (r =−0.53, P = 0.001), DT (r = 0.65, P < 0.001), and IVRT (r = 0.73, P < 0.001). Conclusion: This study suggests that impaired LV relaxation contributes to the heterogeneous atrial conduction in hypertensive patients.
Automatic Cardiac Event Recorders Reveal Paroxysmal Atrial Fibrillation after Unexplained Strokes or Transient Ischemic Attacks
Authors: Barthélémy Jean‐Claude , Féasson‐Gérard Séverine , Garnier Pierre , Gaspoz Jean‐Michel , Costa Antoine Da , Michel Daniel , Roche Frédéric 
Published: July 2003

Background: The etiology of stroke or transitory ischemic attack (TIA) remains frequently unknown. While paroxysmal atrial fibrillation (PAF) is often suspected, its presence remains difficult to establish. Therefore, we investigated the occurrence of PAF episodes in such a population using a long‐term automatic cardiac event recorder. Methods: We prospectively investigated 60 consecutive subjects admitted in our university hospital for stroke (n = 44) or TIA (n = 16), adding long‐term automatic cardiac event recorders, with a target duration of 4 days, to standard investigations, which included 12‐lead ECGs and 24‐hour Holter recordings. Results: In 28 patients no etiology was found for their stroke or TIA. However, one or more than one PAF episode was found in 4 of them (14.3%) using the long‐term automatic event recorder. In the 32 remaining patients, 8 presented with PAF, and this was considered as the cause of their stroke. In both groups, AF was paroxysmal. The PAF episodes' duration went from 1 to 96 hours (mean ± standard deviation, 18 hours and 30 minutes ± 30 hours). Conclusions: Patients suffering PAF episodes after ischemic stroke or TIA were statistically less often recognized using the 24‐hour Holter ECG recording alone than the R‐Test Evolution alone.
ST Segment Analysis by Holter Monitoring:
Authors: Bjerregaard Preben , El‐Shafei Amr , Kotar Susan L. , Labovitz Arthur J. 
Published: July 2003

Background: There has been a renewed interest in ST segment analysis by Holter Monitoring, especially in multicenter clinical trials, but consensus on how to define an ischemic event is missing. We conducted a survey of European and U.S. publications involving ST segment analysis by Holter monitoring from 1975 to 2002 and found no notation of any correction for baseline ST segment depression in 52% of them. In 45% J‐point depression was required in addition to ST segment depression measured either 60 ms (24%) or 80 ms (76%) after the J point. In 28% ST segment elevations were included. Method: Four different criteria for an ischemic event found in our survey were applied to Holter recordings from 66 patients with acute ischemic syndrome enrolled in the Esmolol Myocardial Ischemia Trial (EMIT). Only lead CM5 was used and the analyzer was a Reynolds Medical Pathfinder 600. Results: By the most sensitive method (J + 80), there were 16 (24%) patients who had ischemic events in their Holter recording compared to only 10 (15%) patients if J‐point depression was also required. If corrections were made for baseline ST segment depression, only 3 (4.5%) recordings were positive for ischemia. Conclusion: The outcome of Holter analysis for ischemic events is greatly dependent upon how an ischemic event is defined. Consensus on how to define an ischemic event is urgently needed.
Effect of Phenylephrine Provocation on Dispersion of Repolarization in Congenital Long QT Syndrome
Authors: Khositseth Anant , Nemec Jan , Hejlik Joseph , Shen Win K. , Ackerman Michael J. 
Published: July 2003

Introduction: Syncope and sudden death are associated with sympathetic stimulation in LQT1 while LQT2 patients are more susceptible to arrhythmias during nonexertional states. Abnormal spatial (QTd)‐ and transmural (TDR)‐dispersion of repolarization may indicate increased arrhythmogenicity. This study compares the effect of phenylephrine on QTd and TDR in genotyped LQTS to control (C). Methods and Results: Seventeen LQT1, 12 LQT2, and 18 age‐ and sex‐matched normal controls received 2 mcg/kg of phenylephrine intravenously. At baseline and peak phenylephrine effect, BP, QT, RR, Bazett's QTc, precordial QTd (QTmax−QTmin), and T‐peak to T‐end (Tp‐e) intervals were determined blinded to the patient's clinical and genotype status. Baseline QT intervals and QTc were significantly longer in LQT1 and LQT2 compared to C. Baseline QTd and Tp‐e were greater in LQT2 than either LQT1 or C: QTd = 79 ± 29 ms (LQT2), 53 ± 26 (LQT1), and 45 ± 15 (C) and Tp‐e = 120 ± 30 ms (LQT2), 99 ± 20 (LQT1), and 90 ± 11 (C). Overall, phenylephrine exerted no significant effect on either QTd or Tp‐e except with subgroup analysis of symptomatic LQTS where LQT1 and LQT2 patients had a divergent response with TDR. Conclusions: Phenylephrine‐induced bradycardia decreased TDR in symptomatic LQT1 but increased TDR in symptomatic LQT2. The observed effects of phenylephrine are consistent with the protective effect of beta‐blocker in LQT1 and the increased arrhythmogenicity noted during nonexertional states in LQT2.
P Wave Amplitude and Duration may Predict Immediate Recurrence of Atrial Fibrillation After Internal Cardioversion
Authors: Gorenek Bulent , Birdane Alpaslan , Kudaiberdieva Gulmira , Goktekin Omer , Cavusoglu Yuksel , Unalir Ahmet , Ata Necmi , Timuralp Bilgin 
Published: July 2003

Background: Although internal cardioversion (IC) for atrial fibrillation (AF) is effective at restoring sinus rhythm, immediate recurrence (IR) of AF after IC is a major and largely unpredictable clinical problem. The purpose of the study was to determine the role of P wave duration and amplitude in prediction of IR of AF after IC. Forty‐five consecutive patients undergoing IC for chronic AF were evaluated. Material and Methods: After successful IC, 1‐minute ECG recording was obtained in all patients. P wave duration and amplitude in Lead II and V1 were measured using computer. Forty patients (88%) had successful IC. Thirteen patients experienced IR of AF within 1 minute of restoring sinus rhythm. Results and Conclusion: As a result, the incidence of IR of AF after IC was higher in the patients with shorter P wave amplitude (for lead II P < 0.01, for V1P < 0.01) and larger P wave duration (for lead II P < 0.01, for V1P < 0.05).
Prevalence of Sensing Abnormalities in Dual Chamber Implantable Cardioverter Defibrillators
Authors: Saeed Mohammad , Jin Anna , Pontone Gregory , Higgins Steve , Gold Michael , Harari David , Nunley Steven , Link Mark S. , Homoud Munther K. , Estes N.A. Mark , Wang Paul J. ,   the LESS Investigators
Published: July 2003

Background: The clinical efficacy of ICD therapy depends on accurate sensing of intracardiac signals and sensing algorithms. We investigated the occurrence of sensing abnormalities in patients with dual chamber ICDs. Methods: The study group consisted of all patients with dual chamber ICDs enrolled in the LESS trial and patients implanted with dual chamber ICDs at a single center between January 1997 and July 2000. Electrograms of spontaneous ventricular arrhythmias requiring device intervention were analyzed. Results: A total of 48 patients met the criteria for enrollment. Among the 244 episodes, 215 (88%) were due to ventricular tachycardia and 29 (12%) were due to ventricular fibrillation. Overall undersensing was infrequent with 12 (20%) patients exhibiting on average 2.2 undersensed beats during 26 episodes of ventricular arrhythmias. There was no delay in therapy due to undersensing. Oversensing occurred in 5 (10%) patients resulting in 13 (2.7%) episodes of inappropriate therapy. None of the patients had any lead abnormalities and oversensing resolved after device reprogramming in 4 patients while 1 patient required a separate rate sensing lead. Among patients with oversensing, 4 out of 5 were pacing before the index event while among patients with no oversensing only 5 out of 42 were pacing (P < 0.001). Conclusions: Dual chamber ICDs demonstrate outstanding accuracy of sensing. However, because of the selection of patient population requiring more frequent pacing, oversensing occurs with a significant frequency. Meticulous evaluation in such patients is necessary to minimize the likelihood of oversensing and inappropriate shocks.
Heart Rate Variability Declines with Increasing Age and CTG Repeat Length in Patients with Myotonic Dystrophy Type 1
Authors: Hardin Bradley A. , Lowe Miriam R. , Bhakta Deepak , Groh William J. 
Published: July 2003

Background: Cardiac myopathy manifesting as arrhythmias is common in the neurological disease, myotonic dystrophy type 1 (DM1). The purpose of the present study was to evaluate heart rate variability (HRV) in patients with DM1. Methods: In a multicenter study, history, ECG, and genetic testing were performed in DM1 patients. Results: In 289 patients in whom the diagnosis of DM1 was confirmed by a prolonged cytosine‐thymine‐guanine (CTG) repeat length the most common ambulatory ECG abnormality was frequent ventricular ectopy (16.3%). The 24‐hour time domain parameters of SDNN (SD of the NN interval) and SDANN (SD of the mean NN, 5‐minute interval) declined as age and CTG repeat length increased (SDNN: −8.5 ms per decade, 95% confidence intervals [CI]−12.9, −4.2, −8.7 ms per 500 CTG repeats, CI −15.7, −1.8, r = 0.24, P < 0.001; SDANN: −8.1 ms per decade, CI −12.4, −3.8, −8.8 ms per 500 CTG repeats, CI −15.7, −1.9, r = 0.23, P < 0.001). Short‐term frequency domain parameters declined with age only (total power: −658 ms2 per decade, CI: −984, −331, r = 0.23, P < 0.001; low frequency (LF) power −287 ms2 per decade, CI: −397, −178, r = 0.30, P < 0.001; high frequency (HF) power: −267 ms2 per decade, CI: −386, −144, r = 0.25, P < 0.001). The LF/HF ratio increased as the patient aged (0.5 per decade, CI: 0.1, 0.9, r = 0.13, P = 0.03). Conclusions: In DM1 patients a decline in HRV is observed as the patient ages and CTG repeat length increases.          A.N.E. 2003; 8(3):227‐232
Predictive Value of P‐Wave Signal‐Averaged Electrocardiogram for Atrial Fibrillation in Acute Myocardial Infarction
Authors: Çiçek Dilek , Çamsari Ahmet , Pekdemir Hasan , Kiykim Ahmet , Akkuş Necdet , Sezer Kerem , Diker Erdem 
Published: July 2003

Background: Atrial fibrillation (AF) is a common complication of acute myocardial infarction (AMI) with a reported incidence of 7–18%. Recently, P‐wave signal‐averaged electrocardiogram (P‐SAECG) has been used to assess the risk of paroxysmal AF attacks in some diseases. The aim of this study was to determine prospectively whether patients with AMI at risk for paroxysmal AF would be identified by P‐SAECG and other clinical variables. Methods: A total of 100 patients (mean age: 59 ± 12, 77 male, 23 female) with ST segment elevation AMI were enrolled in this study. Patients with chronic AF were excluded. At entry, all patients underwent standard 12‐lead ECG and in the first 24 hours, P‐SAECG was taken, and echocardiography and coronary angiography were performed on the patients. Patients are followed for a month in terms of paroxysmal AF attacks and mortality. Results: AF was determined in 19 patients (19%). In patients with AF, abnormal P‐SAECG more frequently occurred than in patients without AF (37% vs 15%, P < 0.05). Patients with AF were older (70 ± 14 vs 56 ± 10, P < 0.001) and had lower left ventricular ejection fraction (42%± 8 vs 49%± 11, P < 0.05). AF was less common in thrombolysis‐treated patients (47% vs 74%, P <0.05). Thirty‐day mortality was higher in patients with AF (16% vs 2%, P = 0.05). Conclusions: An abnormal P‐SAECG may be a predictor of paroxysmal AF in patients with AMI. Advanced age and systolic heart failure were detected as two important clinical risk factors for the development of AF.
Diagnosis of Arrhythmogenic Right Ventricular Dysplasia‐Cardiomyopathy: Value of Standard ECG Revisited
Authors: Peters Stefan , Trümmel Martina 
Published: July 2003

Background: The diagnostic dilemma in arrhythmogenic right ventricular dysplasia‐cardiomyopathy (ARVD/C) is that a single diagnostic test does not exist and that there is a need for broadening diagnostic criteria. As standard ECG contributes significantly to clinical diagnosis and represents a tool for screening in family studies ECG data should be revisited. Methods and Results: In a cohort of 265 patients (159 males, mean age 46.8 years) with ISFC/ESC criteria of ARVD/C ECG features were reevaluated.QRS duration in (V1 + V2 + V3)/(V4 + V5 + V6) ≥ 1.2—called localized right precordial QRS prolongation—was present in 261/265 patients (98%) and represents the essential finding. Right precordial epsilon potentials were found in 23% in standard and in 75% in highly amplified and modified recording technique. Right precordial T wave inversions were present in 143 cases (54%) and ST‐segment elevation of different types in 66 patients (25%). Localized prolongation of inferior QRS complexes could be found in 58 cases (22%), complete right bundle branch block with T inversions beyond V2 in most cases in 17 patients (6%), incomplete right bundle branch block in 38 cases (14%), pseudo‐incomplete right bundle branch block in 8 patients (3%), and right precordial R wave reduction in 14 cases (5%). Conclusion: With regard to sensitivity and already known specificity an ECG score for the diagnosis of ARVD/C was developed with high probability of ARVD/C in cases with ≥4 points, possibly without the need for an additional imaging technique.Standard ECG with additional highly amplified and modified recording technique represents a single diagnostic test with high value in the clinical diagnosis of ARVD/C and should be used as a first line tool in noninvasive family screening. A.N.E. 2003; 8(3):238‐245
Novel Compound Heterozygous Mutations in the KCNQ1 Gene Associated with Autosomal Recessive Long QT Syndrome (Jervell and Lange‐Nielsen syndrome)
Authors: Ning Li , Moss Arthur J. , Zareba Wojciech , Robinson Jennifer , Rosero Spencer , Ryan Dan , Qi Ming 
Published: July 2003

Background: The Jervell and Lange‐Nielsen syndrome (JLNS) is the autosomal recessive form of long QT syndrome (LQTS)—a familial cardiac disorder that causes syncope, seizures, and sudden death from ventricular arrhythmias, specifically torsade de pointes. JLNS is associated with sensorineural deafness and has been shown to occur with homozygous mutations in KCNQ1 or KCNE1 in JLNS families in which QTc prolongation is inherited as a dominant trait. This study investigated the molecular pathology of a family with clinical evidence of JLNS. Methods and Results: Single‐strand conformation polymorphism, denaturing high performance liquid chromatography, and DNA sequencing analyses were used to screen for KCNQ1 mutations. Novel compound heterozygous nonsense mutations R518X/Q530X in the C‐terminus of KCNQ1 were identified in both affected dizygotic twins; both the parents and a sibling each carried only one of the mutant alleles and were asymptomatic with modestly prolonged QTc intervals (0.46, 0.50, and 0.45 seconds, respectively). These two nonsense mutations lead to premature termination of C‐terminus with truncation of the postulated assembly domain. Conclusion: Novel compound heterozygous nonsense mutations in C‐terminus of KCNQ1 can cause JLNS.               A.N.E 2003;8(3):246‐250
The Role of c‐Jun N‐Terminal Kinase (JNK) in Parkinson's Disease
Authors: Peng Jun , Andersen Julie 
Published: July 2003

AbstractGiven the critical role that the c‐Jun N‐terminal kinase (JNK) pathway plays in regulating many of the cellular processes which are affected in Parkinson's disease (PD), the possible importance of JNK in disease pathogenesis is being increasingly recognized. Here we review recent findings implicating the JNK signaling pathway in animal models of Parkinson's disease and discuss the relationship between this pathway and the prominent pathological processes observed in the disease state. We suggest that regulation of the JNK signaling pathway may be a central facet in potential treatments for the disease. IUBMB Life, 55: 267‐271, 2003