Toshio Akiyama

A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias

BACKGROUND Patients who survive life-threatening ventricular arrhythmias are at risk for recurrent arrhythmias. They can be treated with either an implantable cardioverter-defibrillator or antiarrhythmic drugs, but the relative efficacy of these two treatment strategies is unknown. METHODS To address this issue, we conducted a randomized comparison of these two treatment strategies in patients who had been resuscitated from near-fatal ventricular fibrillation or who had undergone cardioversion from sustained ventricular tachycardia. Patients with ventricular tachycardia also had either syncope or other serious cardiac symptoms, along with a left ventricular ejection fraction of 0.40 or less. One group of patients was treated with implantation of a cardioverter-defibrillator; the other received class III antiarrhythmic drugs, primarily amiodarone at empirically determined doses. Fifty-six clinical centers screened all patients who presented with ventricular tachycardia or ventricular fibrillation during a period of nearly four years. Of 1016 patients (45 percent of whom had ventricular fibrillation, and 55 percent ventricular tachycardia), 507 were randomly assigned to treatment with implantable cardioverter-defibrillators and 509 to antiarrhythmic-drug therapy. The primary end point was overall mortality. RESULTS Follow-up was complete for 1013 patients (99.7 percent). Overall survival was greater with the implantable defibrillator, with unadjusted estimates of 89.3 percent, as compared with 82.3 percent in the antiarrhythmic-drug group at one year, 81.6 percent versus 74.7 percent at two years, and 75.4 percent versus 64.1 percent at three years (P<0.02). The corresponding reductions in mortality (with 95 percent confidence limits) with the implantable defibrillator were 39+/-20 percent, 27+/-21 percent, and 31+/-21 percent CONCLUSIONS Among survivors of ventricular fibrillation or sustained ventricular tachycardia causing severe symptoms, the implantable cardioverter-defibrillator is superior to antiarrhythmic drugs for increasing overall survival.

Natural course of the S-T segment and QRS complex in patients with acute anterior myocardial infarction.

Abstract Sums of the S-T segment elevation from the 35 lead precordial electrocardiographic map (∑ST35) and Standard 6 lead precordial electrocardiogram (∑ST6) were obtained from 20 patients after acute anterior myocardial infarction and the calculations repeated 2, 4, 12, 24, 48, 72 and 240 hours later. Q and R wave areas were summed (∑Q35, ∑Q6, ∑R35 and ∑R6). ∑ST35 and ∑ST6 values decreased significantly in patients without pericarditis 7 to 12 hours after the onset of symptoms (P

Driving and Arrhythmias: Implications of New Data

Patients with ventricular arrhythmias are often restricted from driving by their physicians for several months. These recommendations are based more on convention than evidence, due to the paucity of data previously available on the safety of driving in these patients. Over the past few years, however, more data have become available that suggests that it is safe to drive within three months of their ventricular tachyarrhythmia. In this paper, we look at this more recent data and make the suggestion that patients with well maintained cardiac function, no recurrent ventricular arrhythmias (i.e. electrical storm) and no persistent medical condition predisposing them to ventricular arrhythmias should be allowed to resume driving soon after their ventricular tachyarrhythmia.

Antiarrhythmic Agents in Older Patients

SummaryThe treatment of ventricular arrhythmias in the elderly population is a challenging problem. Elderly patients are more predisposed to arrhythmias, are less responsive to antiarrhythmic agents, and are more susceptible to the adverse effects of antiarrhythmic agents. Results from recent trials have altered the general approach to management of ventricular arrhythmias.The results of the Cardiac Arrhythmia Suppression Trials (CAST I and II) exemplified the disappointing results from numerous other studies, revealing the overall lack of efficacy of class I agents in reducing mortality in patients with coronary artery disease and asymptomatic premature ventricular complexes (PVCs). The results of CAST I and II also demonstrated the higher likelihood of older patients developing ventricular arrhythmias and toxicity to antiarrhythmic agents. Combined results of these studies have discouraged empirical antiarrhythmic therapy, especially in older patients with asymptomatic PVCs.In contrast, secondary prevention trials with β-blockers in post-myocardial infarction patients have shown definitive survival benefit and reduction in ventricular arrhythmias, especially in the older patient population. Smaller trials with amiodarone have also shown survival benefit in post-myocardial infarction patients with or without PVCs.Management of ventricular tachycardia and fibrillation has become less empirical and more systematic with use of electrophysiologically guided and/or Holter monitor-guided therapy. Sotalol and amiodarone are especially effective agents. The efficacy of implantable cardioverter/defibrillators are also being compared with medical therapy systematically in multicentre trials.In general, empirical antiarrhythmic therapy is discouraged especially in the treatment of asymptomatic PVCs and should be reserved for systematic use in life-threatening arrhythmias.

Ashman phenomenon of the T wave

Abstract In 1947 Gouaux and Ashman1 described a patient with atrial fibrillation in whom the sequence of long-short cycle lengths led to QRS aberration of the QRS complex terminating the short cycle. The long cycle causes the action potential2 and refractory period3–5 of the next beat to lengthen. The impulse that terminates the short cycle is thus likely to meet relatively refractory ventricular conduction tissue.6 Such QRS aberration has been referred to as the Ashman phenomenon. Because the form of the T wave is influenced by both the ventricular repolarization process and the ventricular activation sequence, aberrated QRS complexes of the Ashman phenomenon are usually accompanied by T-wave abnormalities. We report here 2 patients in whom T-wave aberration occurred in the absence of QRS aberration, when short ventricular cycles followed beats of relatively longer cycles. This is the first description of the Ashman phenomenon of the T wave without aberration of the corresponding QRS complex.