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Biomedical subjects

S L Pinski

Publications and source records attributed to S L Pinski.

At least 73 records · Page 4Linked to original sources
PubMed1994

Long-term performance of endocardial pacing leads.

To assess the performance of endocardial pacemaker leads and to identify factors associated with structural lead failure, medical records of 2,611 endocardial pacing leads (in 1,518 patients) implanted between 1980 and 1991, having at least 1 month of follow-up, were reviewed. Leads without structural failure had normal function at the last follow-up date, or were discontinued for reasons other than structural failure (patient death, infection, dislodgment, lead-pacemaker incompatibility, operative complication, or abandonment by telemetry not related to failure). Leads with suspected structural failures were invasively or noninvasively disconnected because of clinical malfunction (loss of capture or sensing, oversensing, elevated thresholds, or skeletal muscular stimulation). Leads with verified structural failures met the criteria for suspected lead failure and also had a visible defect seen in the operating room or on chest roentgenograms, a change in the impedance interpreted by the physician as lead disruption, or a manufacturer's return product report that confirmed structural failure. Variables analyzed included patients' age and gender, paced chamber, venous access, insulation materials, fixation mechanism, coaxial design, polarity, and different lead models. The cumulative lead survival at 5 and 10 years were 97.4% and 92.9%, respectively, for suspected failures; and 98.7% and 97.3%, respectively, for verified failures. Leads in older patients (> or = 65 years old), and leads in atrial position had fewer verified failures (P = 0.014 and P = 0.007, respectively). Unipolar leads also tended to perform better according to the verified definition (P = 0.07).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Safety and diagnostic yield of noninvasive ventricular stimulation performed via tiered therapy implantable defibrillators.

Extensive electrophysiological testing is critical for the effective utilization of sophisticated tachycardia detection and termination algorithms available in tiered therapy ICDs. To evaluate the safety and diagnostic yield of electrophysiological testing via noninvasive ventricular stimulation, we performed 294 electrophysiological studies in 154 patients (age 65 +/- 10; left ventricular ejection fraction 0.36 +/- 0.15) with tiered therapy ICDs. Stimulation was performed under methohexital anesthesia. A total of 918 sustained ventricular tachyarrhythmias were induced (3.1 +/- 2.5 per procedure): monomorphic VT, 550; ventricular flutter, 74; and VF, 246. The results of invasive and noninvasive programmed stimulation were compared for 79 patients who had both studies under similar treatment. Overall concordance was 83%, and did not differ significantly between patients who had the noninvasive stimulation via epicardial or endocardial pacing leads. VF could be induced in 206 of 257 studies (82%), and it was less likely to be induced in patients on amiodarone (74% vs 85%; P = 0.02), or beta blockers (55% vs 83%; P = 0.017). No patient presented a serious complication. Minor complications occurred during 39 studies: transient laryngospasm in 1, unintended delivery of an ICD shock to a conscious patient in 4; induction of sustained atrial fibrillation in 8; need for external rescue defibrillation shocks in 13; and delivery of inappropriate shocks for supraventricular rhythms in 14 studies. Noninvasive ventricular stimulation performed under methohexital anesthesia is safe. Its diagnostic yield compares favorably with that of conventional electrophysiological studies. VF can be induced in a majority of patients. There is good correlation between invasive and noninvasive programmed stimulation for induction of VT. Noninvasive ventricular stimulation may emerge as standard procedure for the initial programming and follow-up of ICDs.

Aged↗
PubMed1994

A technique for rapid transfemoral catheterization of the coronary sinus with multielectrode catheters.

To minimize procedural and fluoroscopic times and avoid the risks of vascular injury and pneumothorax, some investigators have advocated elimination of routine placement of a coronary sinus (CS) catheter during electrophysiological procedures. We hypothesized that expedient and reproducible CS catheterization could be performed with minimal patient risk by utilizing a femoral vein approach. Fifty consecutive patients referred for radiofrequency ablative procedures underwent attempted CS catheterization using a 6-French steerable, quadripolar catheter via a femoral vein. Procedures were performed utilizing single-plane fluoroscopy without contrast angiographic aid by operators experienced in the technique. Successful catheterization was defined by the attainment, in < 15 minutes, of a stable catheter position with the distal electrode at or beyond the lateral margin of the heart. Successful catheterization of the CS was achieved in 47 (94%) patients. Selective pacing of the left atrium without patient discomfort was possible in all, eliminating the need for a right atrial pacing catheter. The median time to successful catheterization was 1.4 minutes (range 0.3-14.7). Only six patients required > 5 minutes. The median fluoroscopic time required was 1.2 minutes (range 0.3-12.7). No clinical variable was predictive of catheterization failure or time to successful catheterization. No complications were observed as a result of this technique. This prospective evaluation demonstrates that catheterization of the CS via a femoral vein approach is highly successful, expedient, and safe. The ability to selectively pace the left atrium may eliminate the requirement for a right atrial catheter.

Adult↗
PubMed1994

Nonthoracotomy- versus thoracotomy-implantable defibrillators. Intention-to-treat comparison of clinical outcomes.

BACKGROUND: Nonthoracotomy-implantable cardioverter/defibrillator (ICD) systems may represent a significant advance in the treatment of patients with life-threatening ventricular arrhythmias, but their merits relative to those of the well-established thoracotomy systems remain largely unknown. The objective of this study was to compare the short- and long-term clinical outcomes after attempted ICD implantation via a nonthoracotomy versus thoracotomy approach in similar groups of patients. METHODS AND RESULTS: Between September 1990 and December 1992, 212 consecutive patients underwent attempted ICD system implantation without concomitant cardiac surgery at a single institution. Approach selection was not randomized but rather was based primarily on hardware availability. Primary comparisons of short- and long-term outcome were performed according to the "intention-to-treat" principle. Implantation was attempted via a nonthoracotomy approach in 120 patients (57%) and via a thoracotomy approach in 92 patients (43%). Prior cardiac surgery was more prevalent in the nonthoracotomy patients; otherwise, groups did not differ significantly in terms of prognostically relevant clinical characteristics. Nonthoracotomy implantation was successful in 101 patients (84%). After crossover to thoracotomy implantation (14 patients), the eventual success rate for ICD system implantation was 96% in the nonthoracotomy group. Thoracotomy implantation was successful in 89 patients (97%). Operative mortality was 3.3% in the nonthoracotomy and 4.3% in the thoracotomy groups (P = .73). Nonthoracotomy group patients were less likely to experience postoperative congestive heart failure (6% versus 16%; P = .02) or supraventricular arrhythmia (6% versus 18%; P = .004) and had significantly shorter postoperative intensive care and total hospitalization. Total hospital costs were significantly lower in the nonthoracotomy group ($32,205 versus $37,265; P = .001). After a follow-up of 16 +/- 9 months, there were 17 deaths in the nonthoracotomy group (none sudden) and 12 deaths in the thoracotomy group (1 sudden). One- and 2-year Kaplan-Meier survival probabilities were .87 (95% CI, .78 to .91) and .80 (95% CI, .68 to .88) in the nonthoracotomy group and .90 (95% CI, .82 to .95) and .87 (95% CI, .77 to .93) in the thoracotomy group (P = .56; log-rank test). CONCLUSIONS: Nonthoracotomy ICD implantation is associated with reduced surgical morbidity, postoperative hospital care requirement, and hospital costs and has similar efficacy in preventing sudden death relative to the thoracotomy approach. From these nonrandomized data, it appears that a nonthoracotomy approach should be considered preferable in most patients requiring ICD therapy.

Aged↗
PubMed1993

Influence of left ventricular function on survival and mode of death after implantable defibrillator therapy (Cleveland Clinic Foundation and Montefiore Medical Center experience).

To determine the influence of left ventricular (LV) function on survival and mode of death in patients with an implantable cardioverter-defibrillator (ICD), sudden death, surgical mortality, total arrhythmia-related death, total cardiac death and total death were retrospectively evaluated in 377 consecutive patients. The outcomes were also compared between patients with an LV ejection fraction > or = 30% (214 patients, group 1) and < 30% (148 patients, group 2). Surgical mortality was 3.9% (1.8% in group 1, 7% in group 2). During the follow-up of 25 +/- 20 months, actuarial survival rates of all patients at 3 years were 96% for sudden deaths, 81% for total cardiac deaths and 74% for total mortality. When the 2 groups were compared, survival rates of groups 1 and 2 at 3 years, respectively, were 99 and 90% for sudden death (p < 0.05), 97 and 84% for sudden death and surgical mortality (p < 0.01), 94 and 80% for the total arrhythmia-related death (p < 0.001), 88 and 68% for total cardiac death (p < 0.0001), and 81 and 62% for total mortality (p < 0.002). In group 2, 73% of total cardiac deaths within 1 year were causally related to the arrhythmia. Thus, in patients with an ICD, sudden death rates were very low. However, total cardiac death and total death rates were relatively higher. The outcomes of patients with an ICD were strongly influenced by the degree of LV dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1993

The role of pacing modality in determining long-term survival in the sick sinus syndrome.

OBJECTIVE: To determine whether the atrial-based pacing modalities ("physiologic pacing") improve survival when compared with single-chamber ventricular pacing in patients with the sick sinus syndrome. DESIGN: Retrospective, nonrandomized study. SETTING: A tertiary care teaching hospital. PATIENTS: A total of 507 patients with a mean age of 66 years who received an initial pacemaker for the sick sinus syndrome between January 1980 and December 1989. Pacing modes were ventricular (22%), atrial (4%), and dual-chamber (74%). MEASUREMENTS: Total and cardiovascular mortality rates. Mean follow-up was 66 months. RESULTS: Independent predictors of total mortality by the Cox proportional hazards model were 1) New York Heart Association functional class (hazard ratio = 1.67/class; 95% Cl, 1.31 to 2.11); 2) age (hazard ratio = 1.62/12-year increment; Cl, 1.28 to 2.05); 3) peripheral vascular disease (hazard ratio = 2.21; Cl, 1.42 to 3.42); 4) bundle branch block (hazard ratio = 2.04; Cl, 1.33 to 3.13); 5) coronary artery disease (hazard ratio = 1.66; Cl, 1.15 to 2.39); and 6) valvular heart disease (hazard ratio = 1.71; Cl, 1.08 to 2.69). The same variables were independent predictors of cardiovascular mortality, with cerebrovascular disease reaching borderline statistical significance (hazard ratio = 1.69; Cl, 1.00 to 2.86). Using univariate analysis, single-chamber ventricular pacing had more than 40% increased risk for both total and cardiovascular death, but the difference was of borderline statistical significance (total mortality: P = 0.053; hazard ratio = 1.43; Cl, 0.99 to 2.07; cardiovascular mortality: P = 0.15; hazard ratio = 1.41; Cl = 0.87 to 2.29). CONCLUSIONS: Because the role of the ventricular pacing mode as a long-term predictor of total and cardiovascular mortality remains inconclusive, a large, randomized study is necessary to confirm whether physiologic pacing provides a substantial reduction in mortality when compared with ventricular pacing.

Aged↗
PubMed1993

Long-term performance of epimyocardial pacing leads in adults: comparison with endocardial leads.

The long-term performance of epimyocardial pacing leads in children is well established, but few studies have analyzed the performance in adults. This issue has clinical relevance in view of the increased use of epimyocardial leads with implantable cardioverter defibrillator and antitachycardia pacing systems. We analyzed 93 epimyocardial pacing "systems" (121 leads: 65 unipolar, 28 bipolar) in adult patients (age 57 +/- 16 years), implanted since January 1980. Two different models were studied: Medtronic 4951 "Stab-on" (n = 35) and Medtronic 6917/6917A "Screw-in" (n = 58). A control group was created by randomly matching each epimyocardial system with two endocardial leads, according to age and year of implant. Epimyocardial and endocardial leads were followed-up for 44 +/- 35 and 43 +/- 35 months, respectively (P = NS). Freedom from failure for epimyocardial leads was 0.91 (95% Confidence Interval [95% CI] = 0.82 to 0.96) at 5 years, and 0.91 (95% CI = 0.69 to 0.98) at 10 years. No difference was found between the two analyzed models. Freedom from failure for endocardial leads was 0.97 (95% CI = 0.93 to 0.99) and 0.90 (95% CI = 0.61 to 0.97) at 5 and 10 years, respectively. Epimyocardial leads had a significantly poorer short-term survival than endocardial leads, secondarily to earlier "technique related" failures (P = 0.03; relative risk 3.0; Wilcoxon test). However, overall long-term performance was similar to endocardial leads. Epimyocardial pacing leads, meticulously implanted and tested, have a long-term performance similar to endocardial pacing leads.

Electrodes, Implanted↗
PubMed1993

Chronic atrial fibrillation and stroke in paced patients with sick sinus syndrome. Relevance of clinical characteristics and pacing modalities.

BACKGROUND: The goal of the report was to study the long-term incidence and the independent predictors for chronic atrial fibrillation and stroke in 507 paced patients with sick sinus syndrome, adjusting for differences in baseline clinical variables with multivariate analysis. METHODS AND RESULTS: From 1980 to 1989, we implanted 376 dual-chamber, 19 atrial, and 112 ventricular pacemakers to treat patients with sick sinus syndrome. After a maximum follow-up of 134 months (mean: 59 +/- 38 months for chronic atrial fibrillation, 65 +/- 37 months for stroke), actuarial incidence of chronic atrial fibrillation was 7% at 1 year, 16% at 5 years, and 28% at 10 years. Independent predictors for this event, from Cox's proportional hazards model, were history of paroxysmal atrial fibrillation (P < .001; hazard ratio [HR] = 16.84), use of antiarrhythmic drugs before pacemaker implant (P < .001; HR = 2.25), ventricular pacing mode (P = .003; HR = 1.98), age (P = .005; HR = 1.03), and valvular heart disease (P = .008; HR = 2.05). For patients with preimplant history of paroxysmal atrial fibrillation, independent predictors were prolonged episodes of paroxysmal atrial fibrillation (P < .001; HR = 2.56), long history of paroxysmal atrial fibrillation (P = .004; HR = 2.05), ventricular pacing mode (P = .025; HR = 1.69), use of antiarrhythmic drugs before pacemaker implant (P = .024; HR = 1.71), and age (P = .04; HR = 1.02). Actuarial incidence of stroke was 3% at 1 year, 5% at 5 years, and 13% at 10 years. Independent predictors for stroke were history of cerebrovascular disease (P < .001; HR = 5.22), ventricular pacing mode (P = .008; HR = 2.61), and history of paroxysmal atrial fibrillation (P = .037; HR = 2.81). CONCLUSIONS: Development of chronic atrial fibrillation and stroke in paced patients with sick sinus syndrome are strongly determined by clinical variables and secondarily by the pacing modality. Ventricular pacing mode predicts chronic atrial fibrillation in patients with preimplant paroxysmal atrial fibrillation but not in those without it.

Actuarial Analysis↗
PubMed1992

Incidence and predictors of loss of pacing in the atrium in patients with sick sinus syndrome.

Atrial and dual-chamber pacemakers may be associated with reduced morbidity in patients with the sick sinus syndrome (SSS). In some patients, however, subsequent development of chronic atrial fibrillation or atrial lead failure make long-term pacing in the atrium not feasible. We analyzed the incidence and predictors of loss of atrial pacing in 395 consecutive patients with SSS (376 with dual-chamber pacemakers and 19 with single-chamber atrial pacemakers). None of them was in established atrial fibrillation at time of implant. Patients were followed-up for 55 +/- 35 months. Actuarial survival of effective atrial pacing was 92.5% at 1 year, 85% at 5 years, and 76.5% at 10 years. Overall, 60 patients lost atrial pacing. The most frequent cause was the development of chronic atrial fibrillation (53 patients). By multivariate analysis (Cox proportional-hazards model), independent predictors of loss of pacing in the atrium were preimplant episodes of paroxysmal atrial fibrillation (PAF) lasting more than 1 hour (P < 0.001; hazard ratio (HR) = 4.3); prior history of PAF for more than 5 years (P < 0.001; HR = 2.67; and endocardial P wave < 2 mV (P = 0.014; HR = 1.96). In a subgroup of patients (n = 187) who had echocardiograms, a left atrium > 50 mm was also an independent predictor of loss of atrial pacing (P = 0.028; HR = 2.28).(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1992

Incidence and predictors of syncope in paced patients with sick sinus syndrome.

UNLABELLED: In spite of a normal pacemaker function, syncope still occurs in some patients with sick sinus syndrome (SSS). Causes often remain unknown. To identify predictors and etiologies of this bothersome symptom, we studied 507 patients who received atrial, ventricular, and dual-chamber pacemakers for SSS. During a mean follow-up of 62 +/- 38 months, actuarial incidence of syncope was 3% at 1 year, 8% at 5 years, and 13% at 10 years. Causes were vasovagal (18%), orthostatic hypotension (25.5%), rapid atrial tachyarrhythmias (11.5%), ventricular tachycardia (5%), acute myocardial ischemia (2.5%), and pacemaker/lead malfunction (6.5%). In 13 patients (29.5%), syncope remained unexplained. The only preimplant predictor for syncope was syncope as primary indication for pacemaker implant. Electrocardiographic correlation with bradycardia was not a predictor of relief of syncope during the follow-up. IN CONCLUSION: (1) syncope in paced patients with SSS has multiple etiologies and may be multifactorial; (2) the only predictor of syncope after pacemaker implant is the occurrence of preimplant syncope as the main indication for pacing; (3) extensive Holter monitoring is not useful to document bradycardiac origin of syncope nor to predict its recurrence; (4) SSS probably overlaps with other entities such as autonomic dysfunction, vasovagal syncope, carotid sinus hypersensitivity, and venous pooling, which would provide an explanation for recurrent syncope in patients with normal pacemaker function.

Actuarial Analysis↗
PubMed1992

Survival after a first episode of ventricular tachycardia or fibrillation.

Recent outcome analyses in ventricular tachycardia (VT) and ventricular fibrillation (VF) have included patients undergoing electrophysiological study (EPS) at tertiary care centers. The selection process involved could introduce bias in the reported populations. We analyzed the outcome of 42 consecutive patients (aged 63 +/- 11 years) admitted to a coronary care unit within 48 hours of a first episode of VT/VF not associated with reversible causes. All patients recovered neurologically and were candidates for EPS. Nine patients (21%) died during the initial hospitalization (none had EPS), and another nine died during a follow-up of 17 +/- 12 months. Actuarial survival at 1 and 2 years was 64% and 62%, respectively. By Cox's model, congestive heart failure functional Class III-IV (P = 0.008; hazard ratio = 3.7) was the only independent prognostic factor. Among patients discharged, subsequent survival did not depend on the performance of EPS or on the antiarrhythmic therapeutic modalities used. Mortality after a first episode of VT/VF is high. Severe congestive heart failure is the most powerful prognostic factor. Studies including successfully referred patients undergoing EPS may not reflect the true natural history of patients with VT/VF.

Actuarial Analysis↗
PubMed1991

Patients with a high defibrillation threshold: clinical characteristics, management, and outcome.

Of 125 patients prepared to receive implantable cardioverter-defibrillators (ICDs) with the patch-patch configuration of the difibrillating electrodes, 23 (18%) had high (greater than or equal to 25 joules) defibrillation thresholds (DFTs). These patients had lower left ventricular ejection fractions (27 +/- 12 vs 34 +/- 13; p less than 0.03) and a higher incidence of previous heart surgery (47% vs 19%; p less than 0.01) than patients with normal DFTs but did not differ in age, type of heart disease, incidence of concomitant heart surgery, or use of antiarrhythmic medication. Defibrillators were implanted in 18 of these 23 patients, 12 during the initial surgery and six after repeat DFT testing 2 weeks later. After 22 +/- 11 months of follow-up, four patients with ICDs died (two suddenly, and two of nonsudden cardiac causes). Two patients without ICDs died of nonsudden cardiac causes. Appropriate shocks were received by five patients (29%) including both who died suddenly later. A high DFT may be more common than previously stated. It is associated with poor ventricular function and previous heart surgery. Repeated DFT testing may be useful in some patients. A high DFT does not preclude successful ICD shocks, but other therapies may provide better results.

Aged↗
PubMed1991

DDIR versus VVIR pacing in patients with paroxysmal atrial tachyarrhythmias.

Patients with sinus node dysfunction (SND) in particular those with tachycardia-bradycardia syndrome and patients undergoing atrioventricular nodal ablation procedures for refractory paroxysmal atrial tachyarrhythmias (PAT), are candidates for single chamber (VVIR mode) or dual chamber rate responsive (DDIR mode) systems. To evaluate the benefits and disadvantages of each pacing mode we retrospectively analyzed 33 patients with a history of frequent PAT who received a VVIR (22 patients); or a DDDR pacemaker (11 patients) programmed to the DDIR mode. The mean follow-up time was 25 and 18 months, respectively. Preimplant left atrial diameter was significantly smaller in the DDIR group. Chronic atrial fibrillation developed in 54% of the VVIR patients and 27% of the DDIR group, but this difference was not significant. Complications of patients with VVIR pacemakers included new mitral and tricuspid insufficiency, stroke, pacemaker intolerance and aggravated congestive heart failure. Patients with DDIR pacemakers had a lower incidence of symptoms and complications. However, this group received more antiarrhythmic medication, required a closer follow-up, and their pacemakers needed frequent reprogramming. Our findings suggest that VVIR is a poor choice for patients with SND, congestive heart failure, and PAT, and that DDIR may be an acceptable alternative.

Anti-Arrhythmia Agents↗
PubMed1991

Retrospective analysis of patients undergoing one- or two-stage strategies for myocardial revascularization and implantable cardioverter defibrillator implantation.

Internal defibrillation leads were placed at time of coronary revascularization in 79 patients. In 34, an implantable cardioverter defibrillator (ICD) was placed simultaneously (group I). A two-stage strategy (selective implantation of the ICD in patients with postoperative spontaneous or inducible ventricular tachycardia [VT]) was followed in 45 patients (group II). Group I patients had failed more antiarrhythmic drug trials (2.9 +/- 1.6 vs 1.5 +/- 1.6; P = 0.02), including amiodarone (62% vs 20%; P less than 0.001). There were four operative deaths in each group. Postoperatively, VT was present in 27 group II patients (60%), 25 of whom received an ICD (two refused device implantation). Patients with postoperative VT had a lower left ventricular ejection fraction than those without VT (33 +/- 9 vs 47 +/- 16; P = 0.01). Actuarial survival at 1, 2, and 3 years was 88 +/- 6, 88 +/- 7, and 88 +/- 10 in group I; and 83 +/- 6, 76 +/- 7, and 76 +/- 11 in group II (NS). No patient without an ICD (based on the postoperative electrophysiological study [EPS]) died suddenly. Five patients (6%) had ICD system infection. Sudden death was largely prevented by either strategy, but relatively high rates of operative mortality and ICD system infection were observed. Prospective studies should identify patients more likely to benefit from one or another strategy.

Aged↗
PubMed1991

Safety of external cardioversion/defibrillation in patients with internal defibrillation patches and no device.

Placement of prophylactic epicardial defibrillation patches at time of open-heart surgery in patients at risk for postoperative arrhythmias has been strongly questioned. Concern has centered on the ability to safely perform subsequent external defibrillation if needed. From 61 patients who were treated with a two-stage strategy we identified 17 who, while wearing epicardial patches and no generator, received external cardioversion/defibrillation for 20 episodes of hemodynamically unstable ventricular arrhythmias. All the patients had one small and one large patch. Eighteen of the episodes were induced during electrophysiological testing (with transthoracic shocks delivered via pad electrodes oriented in an apex-posterior configuration) and two were spontaneous. The episodes occurred at 21 +/- 27 days from patch implant. Thirteen episodes (65%) were converted with one shock at an energy level of 185 +/- 65 J. Seven (35%) required a second shock at 351 +/- 22 J. The accumulated energy requirement was 286 +/- 205 J. No adverse outcomes were noted. The number of episodes requiring more than one shock and the energy requirements were not different from those in a control group of 20 similar arrhythmias treated with the same equipment. Under these conditions, external cardioversion/defibrillation in patients with one large and one small epicardial defibrillation patch was uniformly successful. Further data is needed in the out-of-hospital setting and on the results of external defibrillation in patients with two large patches.

Adult↗
PubMed1990

Pacemaker and defibrillator combination therapy for recurrent ventricular tachycardia.

The judicious use of antitachycardia pacemakers can enhance the benefits of automatic implantable cardioverter defibrillators in certain patients. Both devices were implanted in 10 highly selected patients with drug-refractory pace-terminable sustained ventricular tachycardia. During the observation period of 8 +/- 4.8 months, the automatic pacemakers detected 1,542 episodes of ventricular tachycardia and appropriately managed 1,373. The automatic implantable defibrillator was activated at least once in every patient; on two documented occasions, the defibrillator discharged because the automatic pacemaker accelerated the tachycardia. Concomitant antiarrhythmic drugs could be reduced but not withdrawn. With meticulous device programming and testing, the two systems in combination can work synergistically to manage malignant ventricular arrhythmias in carefully selected patients.

Aged↗
PubMed1990

Adenosine: a new drug for acute termination of supraventricular tachycardia.

Adenosine, recently released for the acute termination of supraventricular tachycardia, is potentially the drug of first choice for this indication. Its notable effects are transient slowing of the sinus rate and atrioventricular nodal block. Adverse effects are transient and clinically insignificant, primarily because of the ultra-short half-life of the drug. Preliminary investigations suggest that adenosine may also be useful in the differential diagnosis of wide QRS complex tachycardias.

Adenosine↗