Biomedical subjects

J S Steinberg

Publications and source records attributed to J S Steinberg.

At least 19 recordsLinked to original sources

PubMed2000

Atrial fibrillation after minimally invasive direct coronary artery bypass surgery.

OBJECTIVES: The study compared the adjusted risk for developing atrial fibrillation (AF) after minimally invasive direct coronary artery bypass surgery (MIDCAB) and coronary artery bypass graft surgery (CABG). BACKGROUND: Atrial fibrillation results in increased morbidity and delays hospital discharge after CABG. Recently, MIDCAB has been explored as an alternative to CABG. Because of differences in surgical approach between the two procedures, the incidence of AF may differ. METHODS: Randomly selected patients undergoing CABG and MIDCAB were examined. Baseline variables and postoperative course were recorded through review of medical record data. RESULTS: The MIDCAB patients were younger than CABG patients (64+/-12 vs. 67+/-10, p<0.04) and had less extensive coronary artery disease (53% of MIDCAB vs. 3% of CABG had single-vessel disease, while 15% of MIDCAB vs. 69% of CABG had triple-vessel disease, p<0.001 for overall group comparisons). No other differences in clinical or treatment data were noted. Postoperative AF occurred less often after MIDCAB (23% vs. 39%, p = 0.02). Other significant factors associated with postoperative AF included age (p = 0.0024), prior AF (p = 0.0007), left main disease (p = 0.01), number of vessels bypassed (p = 0.009), absence of postoperative beta-blocker therapy (p = 0.0001), and a serious postoperative complication (p = 0.0018). Because of differences between CABG and MIDCAB patients, multivariate logistic analysis was performed to determine independent predictors of postoperative AF. The type of surgery (CABG vs. MIDCAB) was no longer a significant predictor of postoperative AF (estimated relative risk for AF in CABG vs. MIDCAB patients: 1.57, 95% confidence interval (0.82-2.52). CONCLUSIONS: Although AF appears to be less common after MIDCAB than after CABG, the lower incidence is due to different clinical characteristics of patients undergoing these procedures.

Aged↗

PubMed2000

Influence of age on atrial activation as measured by the P-wave signal-averaged electrocardiogram.

We used the P-wave signal-averaged electrocardiogram (SAECG) prospectively in 93 healthy volunteers of different ages and observed: (1) a positive correlation between P-wave duration on the SAECG and age (r = 0.39, p < 0.0001); and (2) the proportion of subjects with prolonged P-wave duration was increased with older age. These findings confirm the hypothesis that age-related atrial conduction delay in healthy subjects is present, and detectable by the P-wave SAECG.

Adult↗

PubMed2000

Atrial fibrillation independently prolongs hospital stay after coronary artery bypass surgery.

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia occurring in patients after coronary artery bypass surgery (CABG). HYPOTHESIS: The purpose of this study was to determine whether AF independently prolonged postoperative length of stay (LOS). METHODS: Consecutive patients undergoing elective CABG were identified. Baseline clinical variables, postoperative course including the development of AF, and postoperative LOS were recorded. RESULTS: In all, 216 patients (aged 61 +/- 13 years) were examined. Postoperative LOS was 11.3 +/- 6.4 days (median LOS = 9 days). Fifty-five patients (25%) developed AF. Among 16 variables examined, the univariate predictors of LOS included age (p < 0.001), preoperative left ventricular ejection fraction (p < 0.001), absence of a prior smoking history (p < 0.05), bypass limited to venous conduits (p < 0.001), postoperative AF (p < 0.001), and the occurrence of a postoperative event (p < 0.001). Length of stay for patients who developed AF was significantly longer than that for patients who did not (15.1 +/- 9.0 vs. 10.0 +/- 4.6 days, p < 0.001). After adjusting for other significant variables, the occurrence of AF after CABG independently prolonged LOS: patients who developed AF stayed 3.2 +/- 1.7 days longer than patients who did not (p < 0.001). CONCLUSIONS: Atrial fibrillation lengthens hospital stay after CABG, and its effect is independent of other important variables. Identification of patients who are at risk for AF and successful treatment to prevent AF will likely contribute to major reductions in consumption of health care resources in patients with CABG.

Aged↗

PubMed2000

Implantable cardioverter defibrillator discharge rates in patients with unexplained syncope, structural heart disease, and inducible ventricular tachycardia at electrophysiologic study.

BACKGROUND AND HYPOTHESIS: The implantable cardioverter defibrillator (ICD) is the best available strategy to protect patients from life-threatening ventricular arrhythmia. Although unproven, it is commonly utilized to treat subjects with syncope, a negative clinical workup, structural heart disease, and inducible sustained monomorphic ventricular tachycardia (VT) on programmed electrophysiologic stimulation (EPS). The purpose of this paper was to validate this approach. METHODS: We retrospectively identified 36 subjects who received primary ICD therapy for syncope in the setting of structural heart disease with inducible sustained monomorphic VT on EPS. The cohort was predominantly male (32/36) with underlying coronary artery disease (29/36). The mean left ventricular ejection fraction was 31 +/- 12%, and a third of the patients (12/36) had undergone bypass surgery. RESULTS: The study group was followed for a mean of 23 +/- 15 months (range 3-81 months) and experienced an ICD event rate of 22% at 3 months, which increased to 55% at 36 months. This event rate was comparable with the 66% event rate seen in a group of patients with primary ICD therapy for spontaneous life-threatening VT treated during the same time period. No future predictors of ICD events in the study group could be identified. CONCLUSION: Syncope patients with negative workup, structural heart disease, and sustained monomorphic VT at EPS are at high risk for future tachyarrhythmic events. Based on present evidence, primary ICD therapy in this group appears warranted and justified.

Aged↗

PubMed2000

Advantages and disadvantages of trial designs: a review of analysis methods for ICD studies. AVID Investigators.

General modalities of analyses that have been used for ICD studies are reviewed. Published "typical" examples are briefly described. The historical cohort method is exemplified with previously unpublished data from the Seattle Cardiac Arrest Survivor database. The AVID Study database is used to compare the results obtained from nonrandomized methodologies with randomized methodologies. Particular issues related to the use of the ICD for example, mode of death, inability to blind, selection practice, and treatment decision times make this a natural pedagogic platform.

Bias↗

PubMed1999

Relation between infarct artery patency at late angiography after acute myocardial infarction and signal-averaged electrocardiography.

The angiograms of 89 patients were reviewed from the LATE Ancillary Study (randomized trial of recombinant tissue plasminogen activator vs placebo in patients with symptom onset after 6 hours of myocardial infarction) to determine patency of the infarct-related artery (IRA). In the occluded IRA group (n = 35), the incidence of signal-averaged electrocardiographic abnormality (fQRS > 120 ms) was significantly higher (p = 0.04), the filtered QRS duration was significantly longer (p = 0.007), and the V40 was significantly shorter (p = 0.02), compared with the patent IRA group (n = 54).

Adult↗

PubMed1999

Neurally mediated syncope in 2 patients with extracardiac disease.

We describe the cases of 2 patients with repetitive episodes of syncope with profound bradycardia and hypotension. In both patients, the symptoms were initially thought to be neurally mediated and idiopathic but were ultimately determined to be triggered by serious underlying pathologic processes: a massive and locally invasive tumor of the hypopharynx in 1 patient and a gangrenous gallbladder in the other. Appropriate treatment resulted in a resolution of this syndrome in both patients. These cases emphasize the importance of an appropriate evaluation and broad differential diagnoses for patients with severe bradycardia and hypotension.

Aged↗

PubMed1999

New-onset sustained ventricular tachycardia after cardiac surgery.

BACKGROUND: The de novo occurrence of sustained ventricular tachycardia (VT) after CABG has been described, but the incidence, mortality rate, long-term follow-up, and mechanism are not well defined. METHODS AND RESULTS: This prospective study enrolled consecutive patients undergoing CABG at a single institution. Patients were followed up for the development of sustained VT, and a detailed analysis of clinical, angiographic, and surgical variables associated with the occurrence of VT was performed. A total of 382 patients participated, and 12 patients (3.1%) experienced >/=1 episode of sustained VT 4.1+/-4.8 days after CABG. In 11 of 12 patients, no postoperative complication explained the VT; 1 patient had a perioperative myocardial infarction. The in-hospital mortality rate was 25%. Patients with VT were more likely to have prior myocardial infarction (92% versus 50%, P<0.01), severe congestive heart failure (56% versus 21%, P<0.01), and ejection fraction <0.40 (70% versus 29%, P<0.01). When all 3 factors were present, the risk of VT was 30%, a 14-fold increase. Patients with VT had more noncollateralized totally occluded vessels on angiogram (1.4+/-0.97 versus 0.54+/-0.7, P<0.01), a bypass graft across a noncollateralized occluded vessel (1.50+/-1.0 versus 0.42+/-0.62, P<0.01), and a bypass graft across a noncollateralized occluded vessel to an infarct zone (1.50+/-1.0 versus 0.17+/-0.38, P<0.01). By multivariate analysis, the number of bypass grafts across a noncollateralized occluded vessel to an infarct zone was the only independent factor predicting VT. CONCLUSIONS: The first presentation of sustained monomorphic VT in the recovery period after CABG is uncommon, but the incidence is high in specific clinical subsets. Placement of a bypass graft across a noncollateralized total occlusion in a vessel supplying an infarct zone was strongly and independently associated with the development of VT.

Aged↗

PubMed1999

Efficacy of bretylium tosylate for ventricular tachycardia.

In 20 patients with inducible ventricular tachycardia (VT), intravenous bretylium tosylate infused as a 10-mg/kg bolus followed by 2 mg/min caused no change in refractory periods and did not suppress inducibility of VT. The use of bretylium for the treatment of VT should be reexamined.

Anti-Arrhythmia Agents↗

PubMed1999

Beta-blockers and amiodarone for the primary prevention of sudden cardiac death.

Sudden cardiac death remains a major public health care problem, generally occurring in patients with ventricular dysfunction. Beta-blockers, already of proven benefit for patients after myocardial infarction, have recently been shown to improve functional status and mortality outcomes in patients with heart failure. Amiodarone, a potent antiarrhythmic drug, was recently studied in a number of randomized clinical trials involving patients with heart failure and patients after myocardial infarction. Routine use of amiodarone cannot be recommended in these patient groups, but serious adverse outcomes were not observed. When antiarrhythmic drug therapy is required, amiodarone is the drug of choice for patients with structural heart disease.

Adrenergic beta-Antagonists↗

PubMed1999

Signal-averaged P-wave duration does not predict atrial fibrillation after thoracic surgery.

BACKGROUND: Atrial fibrillation (AF) is the most common dysrhythmia seen early after major thoracic surgery but occurs infrequently after minor thoracic or other operations. A prolonged signal-averaged P-wave duration (SAPWD) has been shown to be an independent predictor of AF after cardiac surgery. The authors sought to determine whether a prolonged SAPWD alone or in combination with clinical or echocardiographic correlates predicts AF after elective noncardiac thoracic surgery. METHODS: Of the 250 patients enrolled, 228 were included in the final analysis. Preoperative SAPWD was obtained in 155 patients who had major thoracic surgery and in 73 patients undergoing minor thoracic or other operations who served as comparison control subjects. The SAPWD was recorded from three orthogonal leads using a sinus P-wave template. The filtered vector composite was used to measure total P-wave duration. Clinical, surgical, and echocardiographic parameters were collected and patients followed for 30 days after surgery for the development of symptomatic AF. RESULTS: Symptomatic AF developed in 18 of 155 (12%) patients undergoing major thoracic surgery and in 1 of 73 (1%) patients having minor thoracic or abdominal surgery, most commonly 2 or 3 days after surgery. In comparison with similar patients undergoing major thoracic surgery without AF, those who developed AF were older (66+/-8 vs. 62+/-10 yr; P = 0.04) but did not differ in SAPWD (145+/-17 vs. 147+/-16, ms) in standard electrocardiographic P-wave duration (105+/-7 vs. 107+/-10 mns), incidence of left-ventricular hypertrophy on 12-lead electrocardiography, male sex, history of hypertension, diabetes, or coronary heart disease. Thoracic-surgery patients at risk for postoperative AF did not differ from all other patients at low risk for AF in clinical or SAPWD parameters. CONCLUSIONS: Under the conditions of this study, SAPWD did not differentiate patients who did or did not develop AF after noncardiac thoracic surgery, and therefore its measurement cannot be recommended for the routine evaluation of these patients. Older age continues to be a risk factor for AF after thoracic surgery.

Adult↗

PubMed1999

Surgical correction of the rearfoot in rheumatoid arthritis.

With proper patient selection and perioperative planning, selective rearfoot arthrodesis in the patient with rheumatoid arthritis is effective in relieving pain and restoring ambulatory status. The overwhelming majority of current literature supports the early fusion of involved rearfoot joints in an effort to arrest the compensatory progression, which yields a rigidly deformed lower extremity. In keeping the patient with rheumatoid arthritis ambulatory, we can positively affect his or her quality of life and prevent the degradation into a sedentary disposition, and therefore heighten the long-term prognosis.

Arthritis, Rheumatoid↗

PubMed1998

Left atrial function is unchanged by implantable defibrillator shocks on hearts in sinus rhythm.

Sixteen patients in sinus rhythm at baseline undergoing implantable cardioverter-defibrillator implantation were monitored with transesophageal echocardiography both before and after direct current cardioversion with currents of 15 to 20 J, for any direct current induced atrial dysfunction. We found no change in the indexes of atrial function or appearance of spontaneous echo contrast in the immediate postshock period by intraoperative transesophageal echocardiography.

Atrial Function, Left↗

PubMed1998

Value of the signal-averaged P wave analysis in predicting atrial fibrillation after cardiac surgery.

Atrial fibrillation (AF) is the most common sustained arrhythmia occurring after cardiac surgery. Beside important implications regarding patient recovery, AF has been shown to substantially lengthen hospital stay--our recent study found a 3-day prolongation after adjusting for all other significant factors. Identification of those at highest risk of AF by clinical or noninvasive characteristics may be a useful strategy for targeted prophylactic therapy. Our data have shown that prolonged atrial conduction as assessed by analysis of the P wave duration from the signal-averaged electrocardiogram (SAECG) imparts a four fold increase in risk for postoperative AF, independently of other measured variables. In addition, abnormal conduction was present on the preoperative P wave ECG (P-SAECG), implying a preexisting substrate that is triggered by surgery. The use of combination abnormal noninvasive variables (eg, abnormal P-SAECG and low left ventricular ejection fraction) can identify groups with a 50% risk of AF, which is nine times as high as when both tests are normal. Thus, the P-SAECG is a useful and accurate predictor of AF after cardiac surgery.

Atrial Fibrillation↗

PubMed1998

Resolution of cardiomyopathy after ablation of atrial flutter.

OBJECTIVES: We sought to serially assess left ventricular (LV) function before and after catheter ablation of atrial flutter (AFI). BACKGROUND: The relation of tachycardia-induced cardiomyopathy to AFI and its response to direct catheter ablation are unknown. METHODS: LV function was assessed in a series of 59 consecutive patients with successful radiofrequency ablation (RFA) of AFI before and after the procedure. Eleven patients had dilated cardiomyopathy (LV ejection fraction [LVEF] <50%) and congestive heart failure (CHF) symptoms and are the subject of this report. LV function was assessed by LVEF on two-dimensional echocardiography and functional status by New York Heart Association (NYHA) CHF classification. RESULTS: Patients were 59 +/- 8 years old, and were all male. Five patients had a preablation diagnosis of idiopathic cardiomyopathy. The preablation LVEF was 30.9 +/- 11.0% and improved to 41.3 +/- 16% (p = 0.005) when measured 7 months after successful ablation. NYHA CHF class improved from 2.6 +/- 0.5 to 1.6 +/- 0.9 (p = 0.002). Six (55%) of 11 patients had normalization of the LVEF, with complete resolution of CHF symptoms. A lower preablation LVEF and functional class predicted nonresolution of dilated cardiomyopathy (p = 0.002 and 0.001, respectively). CONCLUSIONS: Restoration of normal sinus rhythm by RFA in patients with chronic AFI and cardiomyopathy substantially improved LV function. Resolution of dilated cardiomyopathy occurred in the majority of patients. Tachycardia-induced cardiomyopathy may be a more common mechanism of LV dysfunction in patients with AFI than expected, and aggressive treatment of this arrhythmia should be considered.

Adult↗

PubMed1998

Quality of life at baseline: is assessment after randomization valid? The AVID Investigators. The Antiarrhythmics Versus Implantable Defibrillators.

OBJECTIVES: The purpose of this report is to examine whether differences existed between patients who completed a baseline quality of life (QoL) form before being informed about their randomized assignments versus those who completed it after knowing their randomization assignments. METHODS: In the pilot phase of the Antiarrhythmics Versus Implantable Defibrillators (AVID) study (n = 200), 113 patients completed a baseline QoL battery prior to randomization (drug versus defibrillator), 49 additional patients completed this battery after randomization, and 38 patients did not complete this battery. Baseline demographic, clinical and QoL data were compared for these groups. RESULTS: Although the two groups with QoL data were not significantly different regarding various clinical and demographic characteristics, they did have significantly different QoL profiles. Patients with QoL collected before randomization had better overall QoL scores and mental health scores. CONCLUSIONS: These data suggest that patients with worse QoL may be less willing to complete a baseline QoL form in a timely manner or that knowledge of the randomization assignment may have an effect on QoL.

Aged↗

PubMed1998

Does radiofrequency ablation induce a prethrombotic state? Analysis of coagulation system activation and comparison to electrophysiologic study.

INTRODUCTION: Although thromboembolism is an uncommon complication of radiofrequency (RF) ablation, some preliminary reports have suggested that RF ablation results in activation of the coagulation system, possibly increasing this risk. We hypothesized that the insertion of intravenous catheters and their prolonged intravenous placement rather than RF ablation activates the coagulation cascade. METHODS AND RESULTS: Thirty-seven patients, group 1 (n = 21) during RF ablation, and group 2 (n = 16) during routine electrophysiologic studies (EPS), were studied prospectively. Blood was drawn for coagulation and fibrinolytic studies following insertion of venous sheaths (T0), following catheter placement (T1), and 1 hour after completion of RF ablation or EPS (T2). Conversion of prothrombin to thrombin was measured using thrombin-antithrombin complex (TAT) and prothrombin activation peptide (F1+2), and fibrinolytic activity was assessed using D-dimer concentration. Levels of D-dimer increased in group 1 from 823.52+/-323.52 ng/mL at T0 to 1,314.28+/-297.63 ng/mL at T2 (P = 0.005), and in group 2 from 658.15+/-161.70 ng/mL at T0 to 1625+/-641.45 ng/mL at T2 (P = 0.064). TAT levels increased from to 27.74+/-5.6 microg/L at T0 to 52.99+/-5.93 microg/L at T2 in group 1 (P = 0.09), and from 19.79+/-5.14 microg/L at T0 to 73.5+/-24.15 microg/L at T2 in group 2 (P = 0.05). F1+2 concentration increased from 1.52+/-0.30 nmol/L at T0 to 3.06+/-0.41 nmol/L at T2 in group 1 (P = 0.004), and from 1.32+/-0.30 nmol/L at T0 to 3.11+/-0.46 nmol/L at T2 in group 2 (P = 0.087). There was no significant difference in the concentration of the three coagulation variables between group 1 and group 2 at any given time point. No correlation was demonstrable between concentration of D-dimers, TAT, or F1+2 and variables of RF delivery such as cumulative energy, number of RF energy applications, or number of impedance rises. However, a significant positive correlation (r = 0.65, P<0.01) was noted between the duration of the RF ablation procedure and the concentration of D-dimers. CONCLUSION: We conclude that activation of the coagulation cascade in RF ablation procedures is not related to the delivery of RF energy, but is related to the placement of intravascular catheters and to the duration of the ablation procedure.

Adult↗

PubMed1997

Analysis of abnormal intra-QRS potentials. Improved predictive value for arrhythmic events with the signal-averaged electrocardiogram.

BACKGROUND: Using the signal-averaged ECG (SAECG), this study developed a new electrical index for predicting arrhythmic events: abnormal intra-QRS potentials (AIQP). METHODS AND RESULTS: We studied 173 patients followed after myocardial infarction for a mean duration of 14 +/- 7 months. Sixteen arrhythmic events occurred, defined as sudden cardiac death, documented sustained ventricular tachycardia, or non-fatal cardiac arrest. Noninvasive indices of arrhythmia risk were measured, including AIQP, conventional SAECG, Holter, and left ventricular ejection fraction (LVEF). Abnormal intra-QRS potentials were defined as abnormal signals occurring anywhere within the QRS period. They were estimated with a lead-specific, parametric modeling method that removed the smooth, predictable part of the QRS. AIQPs are characterized by the remaining transient, unpredictable component of the QRS and manifest as low-amplitude notches and slurs. A combined XYZ-lead AIQP index exhibited higher specificity (95%) and predictive value (PV) (+PV, 47%; -PV, 94%) than the conventional SAECG in combination with Holter and LVEF (specificity, 89%; +PV, 25%; -PV, 93%). CONCLUSIONS: AIQP improved specificity and predictive value, compared with conventional tests, for prediction of arrhythmic events. AIQP emerged as the best noninvasive univariate predictor of arrhythmic events after myocardial infarction in this study. A review of several other reports shows that AIQP in the present study outperformed the conventional predictive indices reported in those other data sets.

Arrhythmias, Cardiac↗