Mary Jane Sauve

Long-term results of amiodarone therapy in patients with recurrent sustained ventricular tachycardia or ventricular fibrillation

Four hundred sixty-two patients, all with either documented spontaneous sustained ventricular tachycardia or cardiac arrest unresponsive to other antiarrhythmic drugs (2.6/patient), were treated with amiodarone. Thirty-five patients (7.6%) failed to respond or died during the initial oral or intravenous loading phase. The remaining 427 patients were discharged on treatment with oral amiodarone and followed up for up to 98 months. Recurrence of ventricular tachycardia or sudden cardiac death at 1, 3 and 5 years by life-table analysis was 19%, 33% and 43%, respectively, for patients discharged on amiodarone therapy. The sudden cardiac death rate was 9%, 15% and 21%, respectively, at 1, 3 and 5 years. Side effects were reported by 45% of patients after 1 year, by 61% after 2 years and by 86% after 5 years. Amiodarone was discontinued because of side effects in 14%, 26% and 37% of patients after 1, 3 and 5 years, respectively. Incidence rates of recurrence of arrhythmia, sudden cardiac death and side effects were highest in the early months and then decreased. By multivariate analysis, advanced age, low ejection fraction and a history of cardiac arrest were independent risk factors for sudden cardiac death during amiodarone therapy.

Cognitive Deficits in Chronic Heart Failure

Background:Patients with heart failure (HF) have been found to have cognitive deficits, but it remains unclear whether these deficits are associated with HF or with aging or comorbid conditions common in HF. Objectives:The purpose of this study was (a) to determine the types, the frequency, and the severity of cognitive deficits among patients with chronic HF compared with age- and education-matched healthy participants and participants with major medical conditions other than HF, and (b) to evaluate the relationships between HF severity, age, and comorbidities and cognitive deficits. Methods:A sample of 414 participants completed the study (249 HF patients, 63 healthy and 102 medical participants). The HF patients completed measures of HF severity, comorbidity (multiple comorbidity, depressive symptoms), and neuropsychological functioning. Blood pressure and oxygen saturation were assessed at interview; clinical variables were abstracted from records. Participants in the comparison groups completed the same measures as the HF patients except those specific to HF. Results:Compared with the healthy and medical participants, HF patients had poorer memory, psychomotor speed, and executive function. Significantly more HF patients (24%) had deficits in three or more domains. Higher (worse) HF severity was associated with more cognitive deficits; HF severity interacted with age to explain deficits in executive function. Surprisingly, men with HF had poorer memory, psychomotor speed, and visuospatial recall ability than women. Multiple comorbidity, hypertension, depressive symptoms, and medications were not associated with cognitive deficits in this sample. Discussion:HF results in losses in memory, psychomotor speed, and executive function in almost one fourth of patients. Patients with more severe HF are at risk for cognitive deficits. Older patients with more severe HF may have more problems in executive function, and men with HF may be at increased risk for cognitive deficits. Studies are urgently needed to identify the mechanisms for the cognitive deficits in HF and to test innovative interventions to prevent cognitive loss and decline.

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.

Long-term efficacy and toxicity of high-dose amiodarone therapy for ventricular tachycardia or ventricular fibrillation.

Amiodarone was administered to 154 patients who had sustained, symptomatic ventricular tachycardia (VT) (n = 118) or a cardiac arrest (n = 36) and who were refractory to conventional antiarrhythmic drugs. The loading dose was 800 mg/day for 6 weeks and the maintenance dose was 600 mg/day. Sixty-nine percent of patients continued treatment with amiodarone and had no recurrence of symptomatic VT or ventricular fibrillation (VF) over a follow-up of 6 to 52 months (mean +/- standard deviation 14.2 +/- 8.2). Six percent of the patients had a nonfatal recurrence of VT and were successfully managed by continuing amiodarone at a higher dose or by the addition of a conventional antiarrhythmic drug. One or more adverse drug reactions occurred in 51% of patients. Adverse effects forced a reduction in the dose of amiodarone in 41% and discontinuation of amiodarone in 10% of patients. The most common symptomatic adverse reactions were tremor or ataxia (35%), nausea and anorexia (8%), visual halos or blurring (6%), thyroid function abnormalities (6%) and pulmonary interstitial infiltrates (5%). Although large-dose amiodarone is highly effective in the long-term treatment of VT or VF refractory to conventional antiarrhythmic drugs, it causes significant toxicity in approximately 50% of patients. However, when the dose is adjusted based on clinical response or the development of adverse effects, 75% of patients with VT or VF can be successfully managed with amiodarone.

Electrophysiologic testing in bundle branch block and unexplained syncope

Thirty-two patients with bundle branch block and unexplained syncope underwent electrophysiologic testing, including programmed ventricular stimulation with up to triple extrastimuli. The infranodal conduction time (HV) was 70 ms or greater in 12 patients. Pathologic infranodal block during atrial pacing occurred in 2 patients. Unimorphic ventricular tachycardia (VT) was induced in 9 patients (28%) and polymorphic VT in 5 (16%). A permanent pacemaker was implanted in patients with infranodal block during atrial pacing and, generally, in patients with an HV of 70 ms or more. Patients with inducible unimorphic or sustained polymorphic VT were treated with an antiarrhythmic drug. The mean follow-up period was 19 +/- 14 months (+/- standard deviation). Three patients died suddenly: a noncompliant patient with inducible sustained VT; a patient with a normal electrophysiologic study treated empirically with quinidine for premature ventricular complexes; and a patient with an HV of 70 ms and no inducible VT treated with a permanent pacemaker. The actuarial incidence of sudden death was 10% at 45 months of follow-up. Only 2 patients had recurrent syncope; both had a normal electrophysiologic study. Approximately 50% of patients with bundle branch block and unexplained syncope who undergo electrophysiologic testing are found to have a clinically significant abnormality (HV of 70 ms or more, infranodal block during atrial pacing and inducible unimorphic VT), and some patients have more than 1 abnormality. Long-term management guided by the results of electrophysiologic testing generally is successful in preventing recurrent syncope.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of intravenous amiodarone for emergency treatment of life-threatening ventricular arrhythmias

Efficacy, side effects and predictors of response for intravenous amiodarone were evaluated in 46 patients with recurrent drug-refractory sustained ventricular tachycardia or ventricular fibrillation, or both, who were treated with intravenous amiodarone. Of the 46 patients, 27 (58.5%) responded early to intravenous amiodarone and 6 (13%) showed a late response to amiodarone. The majority of patients who responded to intravenous amiodarone did so within the first 2 h of therapy, and all responded within 84 h. Patients with an ejection fraction greater than 25% were more likely to respond (p less than 0.05). Major side effects occurred in 13% of patients. The cumulative 2 year mortality rate due to arrhythmia recurrence or sudden death for responders discharged from the hospital was 23% and the cumulative overall 2 year mortality rate was 46%. In conclusion, intravenous amiodarone is rapidly effective in the majority of patients with recurrent ventricular tachycardia or ventricular fibrillation refractory to other drugs. The poor long-term outcome of patients who require this therapy, respond to it and are discharged on long-term oral amiodarone therapy warrants consideration of other long-term treatment of these patients. Use of intravenous amiodarone is an important new modality in the treatment of drug-refractory malignant ventricular arrhythmias.

Electrophysiologic testing and follow-up of patients with aborted sudden death

Clinical, electrophysiologic and follow-up data were analyzed for 108 patients with aborted sudden death. The mean follow-up interval was 2 years. All patients underwent baseline drug-free invasive electrophysiologic studies. Seventy-five patients (group I) had inducible ventricular arrhythmias (including nonsustained and sustained ventricular tachycardia and ventricular fibrillation) and 33 patients (group II) had no inducible arrhythmias. Noninducibility was not predictive of a favorable outcome, because the incidence of both sudden death and recurrent ventricular tachycardia was similar in the two groups. Treatment guided by electrophysiologic testing was used in 17 patients; in 13 (17%) in group I arrhythmias became noninducible, and in 4 (5%) sustained ventricular arrhythmias became nonsustained after administration of conventional drugs. There was a significantly higher incidence of sudden death and recurrent ventricular tachycardia in the 4 patients with inducible arrhythmias (n = 3, 75%) compared with the 13 patients whose arrhythmias were noninducible (n = 2, 15%) (p less than 0.05). For the group as a whole, 11% died suddenly and 15% had recurrence of ventricular tachycardia. Sixty-four patients were treated with amiodarone and, of these, four (6%) died suddenly during the follow-up period and nine (14%) had recurrent ventricular tachycardia. Ventricular arrhythmias could be induced in 69% of patients with aborted sudden death but inducibility could be suppressed in only 20% of them. The role of therapy guided by electrophysiologic testing could therefore not be fully assessed. The findings reveal a significant recurrence rate of symptomatic, potentially life-threatening ventricular arrhythmias in medically treated patients with aborted sudden death.(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of sotalol for drug-refractory malignant ventricular arrhythmias

Fifty patients with recurrent sustained symptomatic ventricular tachycardia (43 patients) or ventricular fibrillation (7 patients) resistant to a mean of 2.8 + 1.4 antiarrhythmic drugs were treated with sotalol, a beta-adrenergic receptor antagonist, and 45 underwent invasive electrophysiologic testing before and after sotalol therapy. The arrhythmia became noninducible in 10, was slower and hemodynamically well tolerated in 12 and was poorly tolerated in 23. Four patients were empirically treated with long-term administration of oral sotalol as were 21 patients who either had noninducible arrhythmia (10 patients) or had hemodynamically stable ventricular tachycardia (11 patients). In these 25 patients treated with long-term administration of sotalol, there was no recurrence of ventricular tachycardia in the group with noninducible arrhythmia, whereas 37% of patients with inducible ventricular tachycardia had new ventricular tachycardia or sudden death. Programmed ventricular stimulation with up to three extrastimuli proved to be an excellent predictor of drug efficacy and a good predictor of inefficacy. A positive prior response to amiodarone was not a reliable indicator of a positive response to sotalol. Side effects included those attributed to both beta-adrenergic blockade as well as proarrhythmic effects. The latter were observed in two of four patients with a QT interval greater than 600 ms. Sotalol was found to be effective therapy for a subset of patients with ventricular tachycardia unresponsive to type IA drugs.

Cardiac arrest and sudden death in patients treated with amiodarone for sustained ventricular tachycardia or ventricular fibrillation: Risk stratification based on clinical variables

Multivariate analysis of 11 clinical variables was performed in 104 patients with sustained, symptomatic ventricular tachycardia (VT) or ventricular fibrillation treated with amiodarone to determine variables predictive of subsequent cardiac arrest or sudden death. Twenty-five patients (24%) had fatal or nonfatal cardiac arrest after 7.3 +/- 6.2 months (mean +/- standard deviation) of therapy. Multivariate analysis identified an ejection fraction of less than 0.40, syncope or cardiac arrest before amiodarone therapy, and VT (3 or more consecutive ventricular premature complexes) during predischarge ambulatory electrocardiographic monitoring as variables associated with a high risk of subsequent fatal or nonfatal cardiac arrest (p less than 0.03). Patients who had these 3 clinical variables had a much higher predicted incidence of cardiac arrest at 6 months (62%) and 12 months (76%) than did patients with an ejection fraction greater than 0.40, without syncope or cardiac arrest before amiodarone therapy, and without VT during predischarge ambulatory electrocardiographic monitoring (2% and 5%, respectively) (p less than 0.02). Risk stratification using clinical variables can predict which patients are at high risk of recurrent cardiac arrest or sudden death during amiodarone therapy.

Electrophysiologic studies in patients with bundle branch block.

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