ACE inhibitors after myocardial infarction.
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Captopril↗
Biomedical subjects
D Newman
Publications and source records attributed to D Newman.
The implantable defibrillator and antiarrhythmic drugs--competitive and complementary treatment for severe ventricular arrhythmia.
Most patients with a history of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) are at high risk of recurrence. Implanted defibrillators (ICDs) are highly effective in sensing and converting VT or VF to a perfusing rhythm. "Conventional" antiarrhythmic agents, which primarily block cardiac sodium channels, are relatively ineffective in preventing arrhythmia recurrence; amiodarone and sotalol appear to be effective in reducing recurrence and mortality rates, although the extent of benefit is not well understood. Despite the apparent advantage of ICDs, they have short- and long-term complications, are costly, and their benefit in prolonging the quantity or quality of life remains unproven. Randomized clinical trials which compare the effect of ICDs with that of antiarrhythmic drugs on mortality, cost, and quality of life will be necessary to understand how patients with malignant arrhythmias ought to be treated. If an ICD is implanted, adjunctive therapies need to be considered to treat the underlying heart disease and to derive optimum benefit from the device. Drugs may have beneficial or adverse interactions with devices, and the full understanding of these interactions requires further study.
Amiodarone↗
Effects of canine myocardial infarction on sympathetic efferent neuronal function: scintigraphic and electrophysiologic correlates.
We studied the effects of nondecentralized left stellate ganglion stimulation on regional epicardial monophasic action potential duration at 50% (APD50) and 90% (APD90) repolarization from 104 sites in 10 surviving dogs with a chronic myocardial infarction model. These effects were correlated with thallium-201 and iodine-123 metiodobenzylguanidine (MIBG) imaging to identify areas of viable but denervated myocardium. Mean infarct size was 5.2% +/- 0.8% total heart weight, and the planimetered areas of denervation were always larger (18% +/- 4% total heart area). During constant ventricular pacing, stellate stimulation tended to shorten the APD90 only in normally innervated areas (364 +/- 5 to 358 +/- 5 msec) and to increase in denervated areas (358 +/- 5 to 362 +/- 5 msec), (p value not significant (NS) for prestellate and poststellate stimulation; p < 0.05 for difference between denervated vs innervated). The APD50 significantly shortened in innervated areas from 287 +/- 5 to 270 +/- 3 msec (p < 0.05) compared with denervated areas (283 +/- 4 to 274 +/- 5 msec, p = NS). We conclude that MIBG imaging demonstration of denervation identifies areas with impaired shortening of the epicardial APD50 in response to stellate stimulation and that nontransmural myocardial infarction produces areas of denervation larger than areas of necrosis.
Action Potentials↗
Randomized controlled comparison of antitachycardia pacing algorithms for termination of ventricular tachycardia.
OBJECTIVES: This study compared the efficacy and safety of two antitachycardia pacing algorithms in the treatment of ventricular tachycardia. BACKGROUND: There is agreement that antitachycardia pacing should be adapted to tachycardia rate and be delivered in a burst, but the ideal pacing pattern is not well understood. Effective antitachycardia pacing burst patterns include those with a between-burst decrement (SCAN) with or without an additional within-burst decrement (RAMP). METHODS: Prospective randomized crossover comparison of two antitachycardia pacing algorithms (RAMP vs. SCAN) on identical induced sustained ventricular tachycardias was performed. RESULTS: Sixty-five ventricular tachycardias (mean cycle length 364 +/- 74 ms) from 37 invasive studies performed in 29 patients were studied; 86% of patients had coronary artery disease and 72% were receiving antiarrhythmic therapy at the time of study. Of the 65 tachycardias, 40 were identical pairs and 25 were unpaired (including 8 with a > 30-ms difference in cycle length of induced ventricular tachycardia pairs). In the paired pacing trials, conversion to sinus rhythm occurred, respectively, in 85% of SCAN versus 90% of RAMP protocols (p = 0.63, power = 93%) and within 1.4 +/- 0.7 versus 1.7 +/- 1.1 attempts (p = 0.41). Discordance for pacing success was seen in three pairs. In unpaired trials, conversion to sinus rhythm occurred in 73% and 57%, respectively (p = 0.68, power = 88%). Tachycardia acceleration during pacing occurred in 7 (11%) of 65 attempts (5 SCAN, 2 RAMP). Acceleration in unpaired ventricular tachycardia trials was correlated with tachycardia cycle length. Failure to convert ventricular tachycardia was associated with a shorter tachycardia cycle length (p < 0.05). CONCLUSIONS: In the patients studied, adaptive antitachycardia pacing was safe and effective and, when successful, occurred within three attempts of an 8-beat adaptive burst algorithm. Changes in burst pattern did not affect pacing safety or efficacy. Antitachycardia pacing success was dependent on induced ventricular tachycardia cycle length.
Aged↗
Sotalol and type IA drugs in combination prevent recurrence of sustained ventricular tachycardia.
OBJECTIVES: This study assessed the efficacy of the combination of sotalol and either quinidine or procainamide in preventing sustained ventricular tachycardia inducibility and recurrence and prospectively evaluated the ability of the drug combination to prevent ventricular tachycardia recurrence when the arrhythmia remained inducible but was modified. BACKGROUND: Individual antiarrhythmic drugs are often ineffective in preventing the induction and recurrence of sustained ventricular tachycardia. Beta-adrenergic blockade and prolongation of refractoriness may be important components of successful antiarrhythmic therapy in patients with ventricular tachycardia. We reasoned that the combination of sotalol, which has beta-adrenergic blocking properties and prolonged ventricular refractoriness, and quinidine or procainamide, two agents that slow conduction and prolong refractory periods, would be effective therapy in such patients. METHODS: We administered low dose sotalol (205 +/- 84 mg/day) plus quinidine sulfate (1,278 +/- 479 mg/day) or procainamide (2,393 +/- 1,423 mg/day) to 50 patients with spontaneous sustained ventricular tachycardia or fibrillation and inducible ventricular tachycardia. RESULTS: In 21 (46%) of 46 patients, ventricular tachycardia was rendered noninducible at electrophysiologic study (group I), and in 17 patients (37%), inducible tachycardia was modified according to prospectively identified criteria (group II), for a combined 83% response rate. Ventricular refractory periods increased from 252 +/- 24 to 316 +/- 28 ms and from 265 +/- 33 to 316 +/- 24 ms in groups I and II, respectively (p < 0.001), but from 234 +/- 19 to only 286 +/- 13 ms in the group of patients with unmodified ventricular tachycardia inducibility (n = 8, group III, p < 0.001). Cycle length of induced ventricular tachycardia slowed from 324 +/- 62 to 432 +/- 70 ms in group II patients (p < 0.001), whereas it slowed less in group III patients (279 +/- 73 to 314 +/- 63 ms, p = NS). Forty-two of the 50 patients (including all patients in groups I and II) were discharged on treatment with the drug combination. After 25 +/- 19 months of follow-up, the actuarial recurrence rate of ventricular tachycardia was 6%, 6% and 11% at 1, 2 and 3 years, respectively. Among patients in whom this drug combination was unsuccessful at electrophysiologic study (group III) and in those who received alternative therapy after combination therapy was discontinued because of side effects, actuarial recurrence rates were 9%, 14% and 32% at 1, 2 and 3 years, respectively. CONCLUSIONS: The combination of sotalol plus quinidine or procainamide markedly prolongs ventricular refractoriness and slows induced ventricular tachycardia in a high proportion of patients. Patients with modified or noninducible tachycardia have a low rate of arrhythmia recurrence in follow-up. This drug combination deserves further evaluation.
Aged↗
Maintaining continence in nursing home residents through the application of industrial quality control.
Supervisory nurses in seven nursing homes were taught how to implement a quality control management system that permitted the time-efficient assessment of how well a prompted voiding toileting program continued to be implemented by indigenous nursing aides. Random-hour wet checks taken during the 6-month management period revealed a reduction in wetness from 43% to 21% (p < .0001), which was sustained over the full 6-month period.
Aged↗
Head-up tilt testing with and without isoproterenol infusion in healthy subjects of different ages.
Passive head-up tilt testing with or without infusion of isoproterenol is used in the investigation and management of patients with syncope. Twenty-five healthy asymptomatic volunteers prospectively grouped according to age (young [28 +/- 1.7 years]: n = 9; middle [51 +/- 3.3 years]: n = 11; elderly [81 +/- 2.4 years]: n = 5; mean +/- SE) were studied during: (1) supine carotid sinus massage; (2) 60 degrees head-up tilt alone; and (3) infusion of isoproterenol to raise the heart rate 20% above supine baseline, prior to 10-minute repeat tilt. Symptoms occurred in three subjects (12%) and only occurred with passive tilting alone. Two young subjects had syncope with sinus pauses greater than 10 seconds. One elderly subject developed atrial flutter. No subject had symptoms or hypotension during tilt plus isoproterenol or a pause greater than 3 seconds with carotid sinus massage. With passive tilt, mean heart rate increased by 16 +/- 6 beats/min and 18 +/- 7.8 beats/min in the young and middle aged subjects (P < 0.05), but only by 6 +/- 5 beats/min in the elderly (P = NS, supine vs 60 degrees in each group). With head-up tilt plus isoproterenol infusion, the mean heart rate elevation in response to tilt was 17 +/- 9 beats/min, 8 +/- 3 beats/min, and 12 +/- 4 beats/min for the young, middle, and elderly subjects, respectively (P < 0.05, supine vs 60 degrees in each group).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Islet cell cytoplasmic autoantibody reactivity to glutamate decarboxylase in insulin-dependent diabetes.
Individuals with or at risk for insulin-dependent diabetes (IDD) frequently have autoantibodies against an islet cell cytoplasmic (ICA) antigen thought to be a sialoglycolipid. However, we now report that preabsorption of ICA-positive sera with recombinant glutamate decarboxylase (human GAD 65 and/or GAD 67) reduced or blocked the ICA reactivity of 5/18 (27%) new-onset IDD patients and 7/18 (39%) prediabetics. Interestingly, nondiabetic subjects with ICA of > or = 5 yr in duration had GAD-reactive ICA significantly more often (16/24, 67%, P < 0.04) than the diabetic groups. ICA reactivity to GAD was not related to serum ICA titer nor the age of the individual, and in all cases tested was blocked by GAD 65 or GAD 67 with equivalent efficiency. The ICA observed in 21/25 (84%) IDD patients with ICA long after clinical onset of disease (9-42 yr) was reactive to GAD. A natural history analysis of three individuals showed conversions from ICA which was reactive to GAD to a non-GAD-reactive ICA nearer to their clinical onsets of IDD. This study further defines the autoantigens reactive to ICA, and suggests that, whereas ICA that are not reactive to GAD may identify an advanced and more prognostic lesion, GAD-reactive ICA may typify the early or inductive lesion that may or may not progress to clinically significant beta cell injury.
Adolescent↗
Sexual behavior of homosexual and bisexual men attending an HIV testing clinic in Jerusalem 1986/7-1990.
We investigated whether the sexual practices of homosexual and bisexual men attending the Jerusalem AIDS Clinic had changed between 1986/7 and 1990. The responses of a group of 79 homosexual and bisexual men to a questionnaire in 1986/7 were compared to the responses of a group of 37 homosexuals/bisexuals in 1990. Consistent yet statistically insignificant differences in sexual behavior between the 1990 and 1986/7 groups were observed: More individuals were using condoms (53% vs 36% respectively), and at an earlier age. The practice of anal sex was less common (48% vs 67% respectively) and that of oral sex more common (46% vs 27% respectively). These differences were not confounded by the level of education between the two groups. Analyzed separately for homosexuals and bisexuals, the increase in condom use was more noticeable among homosexuals compared with bisexuals, while the decrease in anal sex was greater in bisexuals compared with homosexuals. These results may indicate a trend towards safer sexual behavior in this at risk population, but further studies are needed to support or refute these observations.
AIDS Serodiagnosis↗
An anatomically guided approach to atrioventricular node slow pathway ablation.
Radiofrequency ablation of the "slow" pathway of the atrioventricular (AV) node reentrant circuit may be guided by electrophysiologic ("slow pathway potential") or anatomic landmarks. Experience with a systematic, anatomically guided approach in 25 patients (20 women and 5 men, aged 38 +/- 15 years) with typical AV node reentry is described. The slow pathway is assumed to be the posterior input to the AV node, approaching the nodal region in the corridor between the tricuspid annulus and the orifice of the coronary sinus. A series of radiofrequency lesions are given to interrupt this corridor at its entrance to Koch's triangle. If this is unsuccessful, the series of lesions are repeated progressively at higher levels approaching the AV node. The major end point for success is elimination of the slow pathway as determined by extrastimulus testing. A mean of 1.2 +/- 0.2 ablative sessions (20 +/- 12 applications of energy) achieved clinical success in 24 of 25 patients (96%) at a follow-up of 8.6 +/- 2.2 months. Anterograde Wenckebach cycle length increased from 361 +/- 67 ms to 398 +/- 70 ms (p = 0.01), yet the atrio-Hisian interval in sinus rhythm did not change (69 +/- 17 ms before vs 65 +/- 15 ms after ablation), p = 0.22. Retrograde Wenckebach cycle length was not affected (348 +/- 78 ms before vs 366 +/- 82 ms after ablation). During ablation, transient third-degree AV block occurred in 6 patients with no permanent sequelae. This approach provides a systematic, expedient technique to eliminate slow pathway conduction based on anatomic landmarks.
Adult↗
Use of telemetry functions in the assessment of implanted antitachycardia device efficacy.
Twenty patients (aged 50 +/- 21 years and mean left ventricular ejection fraction 37 +/- 17%) with recurrent ventricular arrhythmias were treated with an investigational, implantable combined antitachycardia-pacing cardioverter defibrillator. The device's telemetry capabilities include both stored (1-second snapshots) and real-time display of endocardial and device-circuit signals. The device can store these before, during and after up to 50 tachycardia and antitachycardia pacing episodes. All stored events are indexed to a 24-hour internal clock. During 10.1 +/- 5.1 months of follow-up, the device was used in 11 of 20 patients. In the entire group, antitachycardia pacing was activated on 44 +/- 14 occasions per patient (total 874) and shock delivery occurred on 8 +/- 14 occasions per patient (total 156). Reconstruction by stored telemetry of all device-therapy episodes was possible. Twenty-six percent of all shocks delivered were not appropriate and were due to atrial arrhythmias in 2 patients and dysfunction of the sensing lead in 3. The absence of a relation between symptoms and appropriate shock delivery was documented in 1 patient. Antitachycardia pace acceleration occurred in 5.3% of cases; 7% of attempts at pacing were unsuccessful and needed shock therapy. It is concluded that the enhanced telemetry available in newer antitachycardia devices enables more accurate assessment of device use and enhances diagnosis of inappropriate therapy delivery.
Electric Countershock↗
Survival after implantation of the cardioverter defibrillator.
The actuarial survival of 60 consecutive recipients of the implanted cardioverter defibrillator (ICD) were compared with 120 matched concurrent medically treated patients using a case-control design. All ICD patients and controls presented with either sustained ventricular tachycardia or ventricular fibrillation. Controls were matched to ICD recipients according to 5 variables: age, left ventricular ejection fraction, arrhythmia at presentation, underlying heart disease and drug therapy status. Mean ages were 58 and 59 years in ICD patients and controls, and the average ejection fractions were 36 and 35%. Coronary artery disease was present in 75 and 79% of ICD patients and controls, respectively. During follow-up, sudden deaths were fewer in ICD recipients than in controls (5 vs 10%, p less than 0.01). At 1 and 3 years, actuarial survival was 0.89 vs 0.72 and 0.65 vs 0.49 for ICD recipients and controls. The 5-year actuarial survival curves were significantly different by the Cox proportional hazards model (p less than 0.05). It is concluded that in this retrospective case-control study, the use of the ICD in the management of patients at risk for sudden death results in improved probability of survival.
Actuarial Analysis↗
Bronchoenteric fistula from an infected internal cardioverter defibrillator.
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Bacterial Infections↗
Speech naturalness and prolonged-speech treatments for stuttering: further variables and data.
It is well known that unusual speech quality may result from stuttering treatments that are based on prolonged speech. However, empirical information concerning the speech quality associated with those treatments is lacking. The present study was designed to contribute such empirical information. Results indicated that speech quality assessments of posttreatment clients, using Martin, Haroldson, and Triden's (1984) speech naturalness scale, gave similar results regardless of whether they were based on monologues or conversations. The speech quality of those clients remained stable at the conclusion of their treatment program. Further, there was a significant, positive correlation between pretreatment speech measures and measures of speech naturalness made after the establishment of stutter-free speech. The subjects whose pretreatment stuttering was the most severe had posttreatment speech naturalness scores that were more than two scale values worse than the subjects whose pretreatment stuttering was the least severe. Speech naturalness scale scores are presented for nonstutterers and posttreatment stutterers and these data are compared with existing findings.
Adolescent↗
Variability of acoustic segment durations after prolonged-speech treatment for stuttering.
Existing literature suggests that one of the effects of treatment based on prolonged speech is increased durations of acoustic segments. However, the external validity of the data concerned may be questioned because the data were not based on spontaneous speech samples and were gathered from subjects with unknown treatment histories. With this in mind, the present investigation used young clients with no history of treatment based on prolonged speech and obtained pretreatment and posttreatment acoustic measures from spontaneous speech samples. Acoustic measures showed no significant posttreatment increases in durations of acoustic segments. However, for the acoustic measure of vowel duration and a measure of articulation rate, posttreatment speech samples showed significantly reduced variability. The potential theoretical and practical relevance of these findings is discussed.
Adolescent↗
Effects of sympathetic stimulation on use dependence of lidocaine, mexiletine, and quinidine in an intact canine model.
The use- or rate-dependent effects of a continuous infusion of lidocaine (n = 6, serum level 3.1 +/- 0.34 micrograms/mL), mexiletine (n = 8, serum level 7.08 +/- 0.90 micrograms/mL), and quinidine (n = 6, serum level 6.8 +/- 1.22 micrograms/mL) were studied in an open chest canine preparation. A use-dependent effect on conduction was assessed by measuring the change in the His to surface ventricular activation (HV) time at differing atrial paced rates during drug infusion. Global sympathetic activation was achieved by nondecentralized left stellate ganglion stimulation (4-10 Hz, 6-12 V, 2 ms) and use dependence at the same cycle lengths was compared. Repolarization times were measured from epicardial monophasic action potentials recorded from the anterior left ventricle throughout the study. There was no significant change in the HV time during control studies with or without left stellate stimulation. Use-dependent slowing of conduction was seen in all studies during drug infusion. This was evident at cycle lengths of 300-190 ms for quinidine and at cycle lengths less than 250 ms for lidocaine and mexiletine. Stellate stimulation attenuated use dependence in all studies. This effect was significant from cycle lengths of 300-190 ms for lidocaine and quinidine and at cycle lengths shorter than 230 ms for mexiletine (p less than 0.05). Stellate stimulation significantly reduced use-dependent prolongation of the HV interval by an average of 60%. During stellate stimulation there was a nonsignificant trend towards cycle length independent shortening of action potential duration both at baseline and in the presence of drugs.(ABSTRACT TRUNCATED AT 250 WORDS)
Action Potentials↗
Urinary albumin and low molecular weight protein excretion in the nephrotic syndrome--sequential studies during corticosteroid treatment.
In a preliminary investigation into the behaviour of low molecular weight proteins in the nephrotic syndrome, we have measured urinary concentrations of albumin, alpha-1-microglobulin (alpha 1-m) and retinol-binding protein (RBP) in six children for up to 11 days during the course of steroid therapy for nephrotic syndrome. The results in part support the concept of independent proximal tubular absorption of albumin and low molecular weight proteins, and indicate that in the nephrotic syndrome the excretion of RBP and alpha 1-m, two generally accepted markers of tubular proteinuria, is anomalous.
Adrenal Cortex Hormones↗
Evidence that the risks of misoprostol outweigh its benefits in stable cyclosporine-treated renal allograft recipients.
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Adult↗