Bereavement and catecholamines

Urinary catecholamine output was studied in 59 middle-aged and elderly persons who were either acutely bereaved (n = 39) or threatened with the loss of a spouse (n = 20). The study was done with the hypothesis that urinary catecholamine output would be elevated among the bereaved subjects both in comparison to norms in the literature for non-stressed controls and to the group of subjects who were threatened with a loss. It was also expected that individually high measures of psychological distress would be associated with high urinary catecholamines. Twenty-four hour urinary output of norepinephrine and epinephrine was observed to be higher than normal during acute bereavement but was not associated with depression scores. No differences were found between those who had experienced an actual loss two months earlier and those who were threatened with a loss. Expected relationships between indices of psychological distress and catecholamine output were not observed. Finally, an association was found between increasing age and higher levels of urinary norepinephrine and epinephrine output among acutely bereaved subjects, suggesting that the adaptation of the sympathetic-adrenal medullary system to stress among older persons is slower.

The mechanisms of ventricular tachycardia in humans determined by intraoperative recording of the electrical activation sequence

We recorded ventricular activation sequence during ventricular tachycardia in 76 patients who underwent surgical therapy of refractory ventricular tachycardia. Ventricular tachycardia arose from a discrete site (focal origination) in 28 patients (37%) or resulted from reentry around scar (macroreentry) in 22 patients (29%). The mechanism responsible for ventricular tachycardia was not discernable in the remaining 26 patients (34%), usually because of inadequacy of activation data. We conclude: (1) although focal originating of ventricular tachycardia is common, more frequently the mechanism is either macroreentry or uncertain, as assessed by conventional recording techniques; thus, a search for the "site of earliest activation" during ventricular tachycardia frequently may fail to direct rationally the operative procedure; (2) conventional techniques for intraoperative study of electrical activation during ventricular tachycardia are inadequate.

Signal-averaged electrocardiographic late potentials in patients with ventricular fibrillation or ventricular tachycardia: correlation with clinical arrhythmia and electrophysiologic study

High-frequency potentials measured in the terminal 40 ms of the signal-averaged QRS complex during sinus rhythm are of abnormally low amplitude in most patients with ventricular tachycardia (VT). However, less is known about high-frequency late potentials in patients with ventricular fibrillation (VF), and the relation between late potentials and arrhythmia inducibility during electrophysiologic study has not been established. Signal-averaged electrocardiography was used to measure high-frequency (more than 25 Hz) late potentials in 24 patients with spontaneous VF, 27 patients with spontaneous sustained VT, and 19 normal subjects, none of whom were receiving antiarrhythmic drugs. Late-potential amplitude in patients with VT was significantly lower than that in patients with VF (p less than 0.02). Late-potential amplitude in patients with VF was not significantly different from that in normal subjects. Ventricular arrhythmia induction was attempted during electrophysiologic study in 46 of the patients with VF or VT. Late-potential amplitude was significantly lower in 26 patients with reproducibly inducible sustained ventricular arrhythmias than in 20 without (p less than 0.001). The correlation between late-potential amplitude and arrhythmia inducibility was independent of that between late-potential amplitude and clinical arrhythmia (VT vs VF).

Treatment with oral lorcainide in patients with sustained ventricular tachycardia and fibrillation

Fifty patients with drug-refractory (failed 7 +/- 2 other drug trials) sustained ventricular tachycardia or fibrillation were treated with oral lorcainide. Twenty-three patients underwent programmed stimulation both before and after oral lorcainide, and all 23 remained inducible, although ventricular tachycardia cycle length was prolonged and mean arterial pressure was higher. Lorcainide was discontinued in 23 patients prior to hospital discharge because of death in four patients, side effects in five patients, spontaneous clinical arrhythmia recurrence in six patients, and ventricular tachyarrhythmias induced at electrophysiologic study in eight patients. Twenty-seven patients were discharged on an average dose of 169 +/- 56 mg twice a day, including 15 in whom ventricular tachycardia remained inducible. During long-term follow-up the drug was discontinued in 15 patients; three because of side effects, three because of clinical nonfatal arrhythmia recurrence, two who selected other alternative therapy, and seven patients who died suddenly due to ventricular tachyarrhythmias. Twelve patients remain on long-term lorcainide. The actuarial 1-year chance of being arrhythmia free was 38.9%, and 1-year cardiovascular and arrhythmia survival rates were 56.8% and 60.4%, respectively. Based on our data we conclude that: In this extremely drug-resistant patient population the clinical efficacy of lorcainide is low; lorcainide should not be used empirically in such highly drug-resistant patients; persistent ventricular tachyarrhythmia inducibility at electrophysiologic study implies a poor prognosis in patients treated with oral lorcainide; the incidence of becoming noninducible during oral lorcainide therapy in highly drug-resistant patients appears low; and for patients in whom the drug seems partially beneficial it could be used in conjunction with a backup automatic implantable cardioverter/defibrillator.

Facilitation of ventricular tachyarrhythmia induction by isoproterenol

Ventricular tachyarrhythmia induction was facilitated during infusion of isoproterenol in 21 of 60 patients with ventricular tachycardia (VT) or ventricular fibrillation (VF) in whom programmed electrical stimulation alone failed to reproducibly induce sustained ventricular tachyarrhythmias. Of 44 patients with no ventricular tachyarrhythmias induced before isoproterenol infusion, 11 had a sustained ventricular tachyarrhythmia and 1 patient had unsustained VT induced by isoproterenol alone or by programmed stimulation during the infusion. In 9 of 16 patients in whom nonreproducible or unsustained ventricular tachyarrhythmias were induced before isoproterenol infusion, more reproducible or more sustained ventricular tachyarrhythmias were induced during the infusion. Tachyarrhythmia induction was facilitated by isoproterenol in 20 of 40 patients with sustained VT clinically, but in only 1 of 20 patients with unsustained VT or VF clinically. Among patients with sustained VT clinically, those with exercise-provoked VT and those who had not been tested with stimulation at a second right ventricular site or in the left ventricle were more likely to have induction facilitated by isoproterenol. Drugs effective against induction of isoproterenol-facilitated ventricular tachyarrhythmias were identified in 13 of 25 trials. These drugs were effective during a mean follow-up of 17 months in 7 of 9 long-term trials.

Heart transplant rejection monitored by signal-averaged electrocardiography in patients receiving cyclosporine

Data from standard and high-frequency signal-averaged electrocardiograms (ECGs) were correlated with the results of 67 endomyocardial biopsies performed in 20 cyclosporine-treated heart transplant recipients. Eight patients (group 1) were in the early postoperative hospitalization period and 12 patients (group 2) were studied after their hospital discharge. The biopsy samples were classified as normal or as indicating early (cellular infiltrate) or definite rejection (myocyte necrosis). The standard ECG parameter studied was the summated QRS voltage in leads I, II, III, V1, and V6. The signal-averaged ECG was evaluated for QRS duration, high-frequency voltage amplitude of the total QRS complex and of its three thirds, peak QRS voltage amplitude, and QRS integrated voltage-time product. The ECG recording obtained at the time of a first normal biopsy sample was considered the normal reference to which additional tracings from the same patient were compared. At the time of subsequent biopsies, the standard ECG parameter showed poor reproducibility (r = .58) and it was inadequate in defining rejection episodes in the early or late postoperative period. The signal-averaged ECG was more reproducible (r = .83) and more accurate in detecting definite rejection during the late posttransplant period than the standard ECG. In group 2 patients, 92% of abnormal signal-averaged ECG recordings were associated with rejection episodes and only 13% of normal tracings were associated with definite rejection. The method was inadequate, however, in monitoring patients during the early postoperative period and in detecting mild forms of rejection in the late postoperative phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Block of inactivated sodium channels and of depolarization-induced automaticity in guinea pig papillary muscle by amiodarone

The electrophysiological effects of amiodarone were studied in guinea pig papillary muscle by means of the single sucrose gap voltage clamp technique. The first time derivative of the upstroke of the action potential was measured as an indicator of the sodium current. The preparations were not voltage clamped during the action potential upstroke. Acute effects of amiodarone (4.4 X 10(-5) M and 8.8 X 10(-5) M; six experiments each) and effects of chronic administration at a single dose level (nine experimental vs. eight control animals) were studied. Results were qualitatively the same for all experimental conditions, and concentration dependent in the acute studies. Amiodarone caused marked use-dependent depression of the first time derivative of the upstroke of the action potential during stimulus trains. For example, at normal resting potential, chronic amiodarone treatment reduced the first time derivative of the upstroke of the action potential of the 16th beat of trains of cycle length 300 msec to 70 +/- 15% (mean +/- SD) of the initial value. This blocking effect was accentuated at more depolarized holding potentials and reduced at hyperpolarized holding potentials. Reduction of the first time derivative of the upstroke of the action potential was found to depend upon sodium channel inactivation. For all experiments, the mean normalized first time derivative of the upstroke of the action potential following a 1-second clamp in the -20 to +20 mV range was 0.92 +/- 0.08 in the control condition and 0.66 +/- 0.20 in the presence of amiodarone (less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The dexamethasone suppression test during bereavement

The dexamethasone suppression test (DST) was given to 13 elderly grieving subjects having a major depressive disorder. Forty-six per cent had some predisposition for depression. All had a post-DST, 4:00 p.m. serum cortisol below 5 micrograms/dl, but these cortisols correlated with Hamilton Depression scores (r = .59, p less than .05).

Clinical efficacy and electrophysiology of imipramine for ventricular tachycardia

Invasive electrophysiologic studies were performed before and during treatment with imipramine in 18 patients with inducible ventricular tachycardia (VT). All received imipramine, 50 mg twice daily for 3 days, and then 100 mg twice daily for 3 days. Imipramine increased the infranodal conduction times (HV) (from 58 +/- 7.8 to 65 +/- 10 ms) and QRS duration (from 133 +/- 21 to 153 +/- 39 ms) and significantly decreased sinus cycle length (from 875 +/- 145 to 711 +/- 116 ms) and maximal corrected sinus nodal recovery time (from 457 +/- 656 to 380 +/- 603 ms). The Wenckebach cycle length tended to decrease and the QT interval to increase, but these changes were not statistically significant. Atrial and ventricular refractory periods, atrioventricular nodal conduction times and induced VT cycle length did not change significantly. Imipramine prevented induction of VT in 2 patients, and VT was more difficult to induce in 1 patient. These 3 patients received chronic imipramine therapy. The 2 patients in whom no VT could be induced while taking imipramine have had no recurrence of arrhythmia at 6 and 12 months of follow-up. The third patient died suddenly 4 months after discharge from the hospital. One patient had worsening of arrhythmias while taking imipramine and 61% had minor adverse effects. The mean combined plasma imipramine and desmethylimipramine concentration at the time of the repeat electrophysiologic study was 227 +/- 114 ng/ml. Imipramine is effective against VT in some patients; however, like other type I antiarrhythmic drugs, the rate of efficacy is low.

Recordings of basal ventricular preexcitation from electrode catheters in patients with accessory atrioventricular connections

To determine the effects of ventricular preexcitation via accessory atrioventricular connections (ACs) on the sequence of basal ventricular activation, electrophysiologic study records of 22 patients with AC were reviewed. In each, AC site was confirmed by mapping done at operation. Local ventricular preexcitation (VP), defined as earlier timing of a local ventricular electrogram relative to the surface electrocardiographic QRS onset in preexcited compared with in normal QRS complexes, was assessed at the coronary sinus and at the ventricular septal summit recorded from the His bundle site. Five patients with concealed AC did not have VP. VP patterns with manifest AC were similar during average fusion QRS complexes and maximum ventricular preexcitation. Left free wall and left crux AC produced VP apparent on the ventricular electrogram recorded at the coronary sinus alone. With anteroseptal AC, VP was noted only at the ventricular septal summit. Posteroseptal AC produced VP that was apparent on the ventricular electrogram recorded at the coronary sinus and on the electrogram of the ventricular septal summit. Right free wall AC preexcited neither of these basal ventricular regions. The observation of VP patterns may help in localizing AC and may be particularly useful in patients without retrograde AC function at electrophysiologic study.

Clinical efficacy and electrophysiology of oral propafenone for ventricular tachycardia

Sixteen patients with ventricular tachycardia (VT) or nonfatal cardiac arrest were treated with propafenone (P), 900 mg/day. Electrophysiologic studies were performed before and during therapy with P. All patients had inducible sustained VT at the baseline study. During P therapy, VT was not inducible in 1 patient, was unsustained in 1 and was harder to induce in 2 patients. P increased the cycle length of VT from 307 +/- 67 to 382 +/- 107 ms. Five patients began outpatient therapy with P, including 2 in whom VT was slowed to less than 125 beats/min. Two are arrhythmia-free during follow-up of 2 and 8 months. P significantly increased intraatrial conduction time (from 44 +/- 12 to 72 +/- 22 ms), AH interval (from 115 +/- 36 to 152 +/- 45 ms), HV interval (from 55 +/- 18 to 92 +/- 42 ms), QRS duration (from 140 +/- 36 to 180 +/- 48 ms) and QT interval (from 402 +/- 30 to 459 +/- 60 ms). P increased atrial (from 247 +/- 36 to 288 +/- 38 ms) and ventricular (from 249 +/- 20 to 277 +/- 32 ms) effective refractory periods, Sinus cycle length did not change, but the corrected sinus node recovery time increased (from 162 +/- 85 to 821 +/- 1,607 ms). P aggravated arrhythmias in 4 patients. The plasma P concentration, measured either at the time of electrophysiologic studies of when therapy was discontinued, was 753 +/- 428 ng/ml. P suppressed ventricular ectopic beats in 33% and increased them in 1 patient. P has antiarrhythmic activity against VT similar to that of other antiarrhythmic drugs and has potential for serious adverse effects in some patients.

Nature of inducible ventricular tachyarrhythmias in a canine chronic myocardial infarction model

A canine model suitable for serial conscious studies was developed to evaluate the nature of sustained ventricular tachyarrhythmias in chronic experimental myocardial infarction. Thirteen dogs underwent left anterior descending coronary artery ligation followed by complete reperfusion; 11 sham-operated dogs served as controls. In this model, ventricular tachyarrhythmias are inducible in most dogs with experimental infarction and in several dogs without this condition. The morphologic features, rate and drug response of the induced arrhythmias are unlike those of human ventricular tachycardia. Tachyarrhythmia induction is facilitated by anesthesia and thoracotomy. This canine infarct model does not adequately imitate human recurrent ventricular tachycardia, but may simulate human sudden cardiac death.

Prognostic significance of the number of induced ventricular complexes during assessment of therapy for ventricular tachyarrhythmias

We analyzed 255 long-term trials of antiarrhythmic therapy, each of which had been evaluated at electrophysiologic study, to identify the maximum number of induced ventricular complexes consistent with the long-term efficacy of antiarrhythmic therapy. All patients had spontaneous and inducible sustained ventricular tachycardia or ventricular fibrillation. The incidence of therapeutic efficacy at 1 month and throughout follow-up was similar for trials in which zero, one, two, three, four, five, six to 10, and 11 to 15 complexes were induced, but significantly lower (p less than .001) for trials in which 16 or more complexes were induced. The cumulative incidence of efficacy at 1 year was 75 +/- 5% for 0 to 5 induced complexes, 72 +/- 11% for six to 10 complexes, 83 +/- 15% for 11 to 15 complexes, 42 +/- 10% for 16 complexes to 15 sec, and 48 +/- 6% for sustained ventricular tachycardia. At 1 year, the incidence of "sudden death-free" survival was higher for patients in trials that prevented initiation of sustained ventricular tachycardia than for those in trials that permitted initiation of sustained ventricular tachycardia (91 +/- 3% vs 75 +/- 6%; p = .01). The duration of the arrhythmia induced at therapy assessment was in the range of 11 to 20 complexes for only 4% of trials. Antiarrhythmic therapy is likely to be effective if as many as 15 complexes are induced at therapy assessment. The best cutoff, between 11 and 20 complexes, is difficult to identify because of the small fraction of trials in this range. Patients in whom initiation of sustained ventricular tachycardia is not prevented are at high risk for arrhythmia recurrence and sudden death.

The automatic implantable defibrillator: local ventricular bipolar sensing to detect ventricular tachycardia and fibrillation

The first-generation automatic implantable defibrillator implanted in man sensed arrhythmias by monitoring a transcardiac electrocardiographic signal. This sensing system reliably detected ventricular fibrillation and sinusoidal ventricular tachycardia but failed to sense all nonsinusoidal ventricular tachycardias. To solve this problem, a new ventricular tachycardia detection scheme was developed using a local ventricular bipolar electrogram and electronic circuits using rate averaging and automatic gain control to permit sensing of electrograms down to 0.1 mV. This detection scheme was tested during electrophysiologic studies in 11 patients with ventricular tachycardia and fibrillation. All 22 episodes of induced ventricular tachycardia with a rate above the selected cutoff were detected after an average of 5.1 +/- 1.8 seconds. No episodes below the rate cutoff were detected. The bipolar circuits also reliably detected ventricular fibrillation. Arrhythmia detection and signal quality in 9 patients receiving automatic defibrillators using the new bipolar rate detection circuit were compared with the findings in 5 patients previously receiving units that sensed arrhythmias using the transcardiac electrocardiographic signal. Compared with the transcardiac monitoring units the newer bipolar units had shorter and more uniform sense times (5.5 +/- 1.4 versus 12.2 +/- 7.1 seconds). It is concluded that malignant ventricular tachyarrhythmias can be sensed accurately using bipolar rate detection and that this system has numerous advantages over the previously used transcardiac electrocardiographic signal.

Amiodarone: clinical efficacy and toxicity in 96 patients with recurrent, drug-refractory arrhythmias

Ninety-six patients with recurrent, drug-refractory tachyarrhythmias were treated with amiodarone for 8.0 +/- 7.5 months (range 1 day to 27 months): 77 for recurrent ventricular tachycardia or ventricular fibrillation (VT/VF), two for complex ventricular ectopy, and 17 for supraventricular tachyarrhythmias. The actuarial incidence of successful amiodarone therapy was 52 +/- 7% at 12 months and 28 +/- 9% at 24 months for patients with VT/VF. Neither patient with complex ventricular ectopy was successfully treated. Among the patients with supraventricular tachyarrhythmias, 64.7% were successfully treated for 7.7 +/- 7.6 months (range 1 to 22 months). Amiodarone toxicity occurred in 66 of 91 patients (72.5%) treated for more than 1 week. Fourteen patients had therapy-limiting toxicity. Of these 14, six had pulmonary toxicity, four had arrhythmia exacerbation, one had hepatitis, one had renal toxicity, one had rash, and one had erythema nodosum. The actuarial incidence of therapy-limiting side effects was 27 +/- 7% at 15 months. We conclude that amiodarone is useful in the treatment of refractory tachyarrhythmias but that the rate of efficacy in VT/VF is lower and the incidence of significant toxicity is higher than has been generally appreciated.