Genetically defined therapy of inherited long QT syndrome.
Explore the source record for details and available documents.
Humans↗
Biomedical subjects
S L Pinski
Publications and source records attributed to S L Pinski.
Cost effectiveness of administration of intravenous anesthetics for direct-current cardioversion by nonanesthesiologists.
Well-trained nonanesthesiologists can safely and effectively administer IV anesthetics for cardioversion. This practice results in considerable cost savings without compromising patient care.
Aged↗
Paradoxical failure of QT prolongation during cardioinhibitory neurocardiogenic syncope.
QT modulation was explored in 31 patients with cardioinhibitory neurocardiogenic syncope. Despite a marked in increase in RR intervals, the QT interval remained stable.
Adult↗
Supernormality with cycle length-dependent intra-His alternans: a new cause of group beating.
This article describes a patient with baseline infranodal conduction disease. Following the administration of intravenous procainamide, the patient developed group beating. Careful electrophysiological evaluation revealed that the group beating was due to alternating intra-His conduction times. Systematic analysis of paced and spontaneous events provides strong evidence that the alternans results from supernormality within the His bundle.
Anti-Arrhythmia Agents↗
Clinical presentation of endocardial pacing lead malfunction.
This study highlights the wide spectrum of manifestation of pacing lead malfunction. Patients judged to be pacer dependent or in whom ventricular lead malfunction is suspected, and patients with severe symptoms before pacemaker implantation, should be considered at high risk for the development of hemodynamic compromise; prompt hospital admission and pacing lead replacement should be performed.
Aged↗
Hospital readmission in patients treated with tiered-therapy implantable defibrillators.
BACKGROUND: We wished to determine the incidence, reasons, costs, and predictors of cardiac-related hospital readmission in patients with tiered-therapy implantable defibrillators. Hospital readmission in patients with defibrillators reduces their quality of life and increases the cost associated with such therapy. METHODS AND RESULTS: We retrospectively studied 65 consecutive local patients (median age, 67 years; median ejection fraction, 0.34) who underwent tiered-therapy defibrillator implantation at this institution. Patients were followed for a median of 19 months (interquartile range, 10 to 27 months). The cause, duration, costs, and predictors of cardiac-related rehospitalizations were analyzed. There were 76 cardiac admissions for 34 patients. The rate of cardiac-related hospital readmission was 0.72 per patient-year of follow-up. Arrhythmia-related admissions accounted for 43 of such admissions in 24 patients. Actuarial freedom from cardiac-related admissions was 0.57 and 0.40 at 1 and 2 years, respectively. The median length of stay for hospital readmissions was 5 days (interquartile range, 3 to 8 days). The median cost per admission was $5842 (interquartile range, $3549 to $12 170). The time to first readmission and the total rehospitalization time per year of follow-up were associated with a poor preimplant New York Heart Association functional class. Readmission for cardiac arrhythmias was not predicted by clinical parameters. CONCLUSIONS: Rehospitalization for cardiac reasons is common in patients receiving implantable defibrillators and is responsible for substantial resource consumption. The need for readmission for arrhythmia-related reasons cannot be predicted by clinical parameters at the time of device implantation.
Aged↗
Natural history of isolated bundle branch block.
The purpose of this study was to determine the long-term outcome of patients with bundle branch block (BBB) who have no clinical evidence of cardiovascular disease. Among 110,000 participants in a screening program, 310 subjects with BBB without apparent of suspected heart disease were identified. Their outcome after a mean follow-up of 9.5 years was compared with that of 310 similarly screened age- and sex-matched controls. Among the screened population, isolated right BBB was more prevalent than isolated left BBB (0.18% vs 0.1%, respectively; p<0.001), and the prevalence of each abnormality increased with age (p<0.001). Total actuarial survival was no different for those with left BBB or right BBB and their respective controls. Cardiac mortality, however, was increased in the left BBB group when compared with their controls (p=0.01, log rank test). Left BBB, but not right BBB, was associated with an increased prevalence of cardiovascular disease at the follow-up (21% vs 11%; p=0.04). In the absence of clinically overt cardiac disease, the presence of left BBB or right BB is not associated with increased overall mortality. Isolated left BBB is associated with an increased risk of developing overt cardiovascular disease and increased cardiac mortality.
Adult↗
Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) Investigators.
BACKGROUND: The presence of left bundle-branch block on the electrocardiogram may conceal the changes of acute myocardial infarction, which can delay both its recognition and treatment. We tested electrocardiographic criteria for the diagnosis of acute infarction in the presence of left bundle-branch block. METHODS: The base-line electrocardiograms of patients enrolled in the GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) trial who had left bundle-branch block and acute myocardial infarction confirmed by enzyme studies were blindly compared with the electrocardiograms of control patients who had chronic coronary artery disease and left bundle-branch block. The electrocardiographic criteria for the diagnosis of infarction were then tested in an independent sample of patients presenting with acute chest pain and left bundle-branch block. RESULTS: Of 26,003 North American patients, 131 (0.5 percent) with acute myocardial infarction had left bundle-branch block. The three electrocardiographic criteria with independent value in the diagnosis of acute infarction in these patients were an ST-segment elevation of 1 mm or more that was concordant with (in the same direction as) the QRS complex; ST-segment depression of 1 mm or more in lead V1, V2, or V3; and ST-segment elevation of 5 mm or more that was disconcordant with (in the opposite direction from) the QRS complex. We used these three criteria in a multivariate model to develop a scoring system (0 to 10), which allowed a highly specific diagnosis of acute myocardial infarction to be made. CONCLUSIONS: We developed and validated a clinical prediction rule based on a set of electrocardiographic criteria for the diagnosis of acute myocardial infarction in patients with chest pain and left bundle-branch block. The use of these criteria, which are based on simple ST-segment changes, may help identify patients with acute myocardial infarction, who can then receive appropriate treatment.
Aged↗
Early electrocardiographic diagnosis of acute myocardial infarction in the presence of ventricular paced rhythm. GUSTO-I investigators.
Explore the source record for details and available documents.
Aged↗
Performance of implantable defibrillator pacing/sensing lead adapters.
The wide variety of implantable defibrillators (ICDs) available from different manufactures and the lack of universal industry standards has resulted in the frequent need for lead adapters at time of ICD implant or change. We analyzed the performance of 81 consecutive ICD sensing/pacing lead adapters used between 1988 and 1993. A total of 66 adapters was used for new epicardial systems, and 15 adapters served as lead connectors during ICD generator replacement. Pacing/sensing lead adapters used were: model LA-201 (n = 28; 34.5%); model 030-308 (n = 26; 32%); model 5866-24 (n = 15; 18.5%); and miscellaneous (n = 12; 15%). After a mean follow-up of 21 +/- 16 months, nine pacing/sensing lead adapters had documented or strongly suspected failure. Most often pacing/sensing lead adapters presented clinically as frequent aborted shocks. Actuarial probability of freedom from failure for model LA-201 was 83% at 1 year, and 72% at 2 and 3 years; this was poorer than for the other sensing leads combined (P = 0.01; hazard ratio = 4.92; 95% confidence intervals = 1.2-20; log-rank test). In conclusion, pacing/sensing lead adapters are a potential source of ICD system complications. Performance is dissimilar among different models; specifically, model LA-201 may not be safe in the long-term, and patients with this lead adapter need to be closely monitored.
Actuarial Analysis↗
Paradoxical shortening of the second PR interval during 3:2 atrioventricular nodal block.
A patient with 3:2 second-degree AV block after acute inferior wall myocardial infarction showed consistent PR interval shortening on the second conducted beat in each periodicity. Intracardiac electrophysiologic evaluation revealed that the site of block was nodal. A typical Wenckebach pattern with prolongation of the AH interval was noted. The shorter PR resulted from a paradoxical shortening of the HV interval in the second beat, most likely due to supernormal conduction in the setting of concomitant trifascicular disease.
Aged↗
The proarrhythmic potential of implantable cardioverter-defibrillators.
The implantable cardioverter-defibrillator (ICD) is remarkably effective in preventing sudden cardiac death in high-risk patients, but it also has the capacity to provoke or worsen cardiac arrhythmias. Tachyarrhythmias or bradyarrhythmias may result from the delivery of antitachycardia or antibradycardia therapies by tiered-therapy defibrillators. This proarrhythmia, although rarely fatal, increases the morbidity associated with defibrillator therapy. Proarrhythmia is related as much to suboptimal programming as to technical limitations of the device. The proarrhythmic potential of ICD therapy can be minimized by tailoring the "electrical prescription" according to characteristics of the clinical arrhythmia and individual ICD idiosyncrasies.
Cardiac Pacing, Artificial↗
Implantable cardioverter-defibrillators: implications for the nonelectrophysiologist.
PURPOSE: To review clinical scenarios in which nonelectrophysiologist physicians may interact with patients who have implantable defibrillators. DATA SOURCES: Peer-reviewed original articles and reviews addressing aspects of implantable defibrillator therapy that are relevant to the clinician. DATA SYNTHESIS: The capacity of implantable defibrillators to recognize and treat tachyarrhythmias can be temporarily disabled by placing a magnet on top of all devices. General surgery, radiotherapy, lithotripsy, and electroconvulsive therapy can usually be safely done under continuous electrocardiographic monitoring in patients with implantable defibrillators. The device should be deactivated before the procedure is done and reactivated and reassessed immediately afterward. Magnetic resonance imaging is usually contraindicated in patients wit implantable defibrillators. The presence of an implantable defibrillator should not deter standard resuscitation techniques. Multiple defibrillator discharges in a short period of time represent a serious problem. Causes of multiple discharges include ventricular electric storm, inefficient defibrillation, nonsustained ventricular tachycardia, and inappropriate shocks caused by supraventricular tachyarrhythmias or oversensing of signals. These patients should be initially evaluated in a setting that allows electrocardiographic monitoring and cardiac resuscitation. The defibrillator should be deactivated if inappropriate firing is documented. Infections of implantable defibrillator systems are potentially life-threatening, and empiric oral antibiotic therapy should never be given when this possibility exists. Adjustment disorders specific to the defibrillator, including anxiety with secondary panic reaction; defibrillator dependence, abuse, or withdrawal; and imaginary shocks are not uncommon. CONCLUSIONS: Defibrillator therapy has become increasingly popular and complex. A basic understanding of these devices and skills in the short-term management of device-related problems is valuable for most physicians. These management guidelines will facilitate delivery of optimal care when specialized staff and material resources are not available.
Cardiopulmonary Resuscitation↗
Low incidence of lead related complications associated with nonthoracotomy implantable cardioverter defibrillator systems.
UNLABELLED: Implantable cardioverter defibrillators (ICDs) are increasingly being implanted without the need for thoracotomy. Long-term lead performance and stability were evaluated in 150 consecutive patients in whom 1 of 3 nonthoracotomy ICD lead systems was implanted over a 3-year period from September 1990. RESULTS: Twelve (8%) patients (7 males, 5 females) experienced 13 lead complications during a follow-up period of 12 +/- 10 months. Complications were related to intracardiac leads in 7 (4 dislodgments, 2 fractures, 1 right ventricular perforation) and patch leads in 6 (2 folding, 1 fracture, 1 erosion, and 2 hematomas) cases. Freedom from lead related complications at 1 year was 92% (95% confidence interval, 86%-95%). A significant difference in freedom from lead complications between the two most frequently implanted lead systems was observed (P = 0.02). Complication rates were similar in the initial 75 and the more recent 75 implants (P = 0.5). The median time between lead implant and detection of complications was 37 days (range 3-1,147). Complications were diagnosed before hospital discharge in only two cases. In five patients, complications were asymptomatic and in three of these, reoperation was required due to inadequate defibrillation thresholds. Reoperation was necessary in 9 of 12 patients. CONCLUSIONS: Nonthoracotomy ICD lead systems are associated with a low complication rate. Complications may or may not cause symptoms, usually occur after hospital discharge, and require reoperation. Complications are not related to a "learning curve." There is a significant difference in performance between different lead systems.
Defibrillators, Implantable↗
Single-chamber ventricular pacing is not associated with worsening heart failure in sick sinus syndrome.
Ventricular pacing (with loss of normal atrioventricular synchrony) has been considered to have a role in the development or progression of congestive heart failure (CHF) in patients with sick sinus syndrome (SSS). No rigorous study has tested this hypothesis. Five hundred seven consecutive patients with SSS who received an initial pacemaker from January 1980 to December 1989 were studied. Atrial or dual-chamber pacemakers were implanted in 395 patients and ventricular pacemakers in 112. After a mean follow-up of 65 +/- 37 months, 97 patients (19%) developed new CHF or increased their New York Heart Association functional class. By univariate analysis, preimplant predictors for these events were left ventricular dysfunction (p < 0.001), valvular heart disease (p = 0.004), peripheral vascular disease (p = 0.005), diabetes (p = 0.02), coronary artery disease (p = 0.02), high New York Heart Association functional class (p = 0.03) and complex ventricular arrhythmia (p = 0.03). By multivariate analysis (logistic regression), the only predictors for CHF were valvular heart disease (p = 0.002; odds ratio [OR] 2.51), peripheral vascular disease (p = 0.003; OR 1.7) and complex ventricular arrhythmia (p = 0.027; OR 2.74). When the analysis was restricted to patients who had preimplant assessment of left ventricular function, independent predictors for CHF were left ventricular dysfunction (p < 0.001; OR 1.66), and complex ventricular arrhythmia (p < 0.001; OR 1.75). In conclusion, progressive or new-onset CHF is a consequence of the underlying cardiovascular disease. In the present population of patients with SSS, ventricular pacing mode was not associated with an increased incidence of CHF.
Aged↗
Evolving concepts in radiofrequency catheter ablation of atrioventricular nodal reentry tachycardia.
Our results and those of others (Table I) suggest that both anatomic and electrogram (potential) approaches are highly successful in eliminating AVNRT. The use of slow-pathway potentials appears to minimize lesion delivery and to be associated with a very small likelihood of complete AV block. Approaches aimed directly at the midseptum also appear to reduce lesion delivery. It is important, however, to understand that the fast and slow AV-nodal pathways are not always confined to anterosuperior (fast) and posteroinferior (slow) locations (at least as they are determined fluoroscopically). On occasion, the slow pathway may be ablated anteriorly and the fast pathway posteriorly. Our three inadvertent successful fast-pathway ablations support these findings. We prefer to conceptualize the AV node as having three ablation zones. Ablation in the anterosuperior zone most often affects fast-pathway conduction; ablation in the posteroinferior zone most often affects slow pathway conduction; and ablation in the midseptal region predominantly affects slow-pathway conduction. Lesions applied to the midseptum do, however, appear more likely to affect inadvertently the fast (or both) pathway(s), probably because of the anatomic convergence of the posteroinferior and anterosuperior AV-nodal approaches in this region. A preliminary report by Wu et al. supports this three-zone concept. The subsequent larger series reported by this group has raised concern that midseptal approaches may be associated with too great a risk of complete AV block. On the other hand, approaches guided exclusively by potentials may be associated with much longer procedure times. Controversy exists over the acceptable end point for ablation procedures. We have not found it necessary routinely to eliminate dual-nodal conduction to maintain a low (3.2%) overall recurrence rate. Aggressive attempts to eliminate all evidence of slow-pathway conduction must be balanced against the risk of inadvertent complete AV block. In conclusion, cumulative data and our clinical experience with ablation of AVNRT suggest that it is possible to be both pragmatic and highly successful. The key components of our approach are (1) an anatomically based, systematic, time-limited search for potentials; (2) elimination of unnecessary lesions that are too atrial or too ventricular to involve the reentrant circuit; (3) a caudocephalad approach that avoids excessively anterior initial lesions, which may result in inadvertent complete AV block; and (4) avoidance of unnecessary lesions in the most inferoposterior sector, which results in patient discomfort and low clinical efficacy. This approach is safe (with minimal risk of AV block), reproducible, and efficacious.
Adolescent↗
Selection bias in electrophysiologically-guided therapy of sustained ventricular tachyarrhythmias.
To analyze if patient selection bias could contribute to the improved prognosis reported for ventricular tachycardia (VT) and ventricular fibrillation (VF) when therapy is guided by electrophysiologic studies (EPS), we studied 90 consecutive patients admitted to a tertiary referral center with recent VT/VF who were candidates for EPS. Seventeen patients (19%) died during the initial hospital admission, and 30 (33%) died after discharge. Survival probability was 0.83 (95% confidence interval [CI], 0.74-0.90); 0.67 (95% CI, 0.56-0.75); and 0.53 (95% CI, 0.42-0.63) at 1 month, 1 year, and 3 years, respectively. Of the 56 patients (62%) who underwent EPS during their initial hospitalization, only 1 died during that admission. Patients in whom EPS could not be performed had characteristics associated with a poorer prognosis. NYHA functional class (p = 0.005), inability to perform baseline EPS (p = 0.003) and use of digoxin (p = 0.016) were independent predictors of death. Early in-hospital mortality in patients with VT/VF remains high. Thus, omission of these deaths in reports of EPS-guided therapy creates incomplete, biased cohorts. Furthermore, there may be a bias toward a healthier population among hospital survivors undergoing EPS. These findings may contribute to better outcomes in current series compared to historical controls.
Aged↗
Memory T waves after radiofrequency catheter ablation of accessory atrioventricular connections in Wolff-Parkinson-White syndrome.
Generalized, extensive electrical repolarization abnormalities, represented by negative or abnormally peaked T waves, are frequently observed after radiofrequency catheter ablation of overt accessory atrioventricular (AV) connections in Wolff-Parkinson-White (WPW) syndrome. Two mechanisms have been proposed to explain these changes: subendocardial injury, secondary to the application of radiofrequency lesions, and memory T waves. The purpose of this study is to evaluate the electrocardiographic (ECG) changes in patients with overt and concealed accessory AV connections after ablation. Fifty-one patients with accessory AV connections who underwent successful radiofrequency ablation were included in the study. Twenty-four patients with clear, manifest, and permanent preexcitation (group 1) were compared with 27 patients with concealed accessory AV connections (group 2). Electrocardiograms were obtained in all patients before ablation, shortly after ablation (within 4 hours), and late after ablation (6 weeks). The frontal and horizontal QRS-T angles in the ECGs, number of lesions, total Joules applied, total peak creatine kinase, and total peak creatine kinase-MB units were compared in both groups. Of the 24 patients with overt accessory AV connections, 23 (95.8%) demonstrated repolarization abnormalities in the ECG shortly after the procedure that reverted almost completely at 6 weeks. Of the 27 patients with concealed accessory AV connections, only 2 (7.4%) demonstrated repolarization abnormalities after the ablation (P < .0001). The persistence of an abnormal QRS-T angle immediately after ablation in patients with overt accessory AV connections is caused by an abnormality in the T wave axis, opposite to the direction of the normal QRS axis.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗