American heart journal
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American heart journal · Jul 1989
Nonventricular arrhythmias as precursors of ventricular fibrillation in patients with out-of-hospital cardiac arrest.
Ventricular tachycardia (VT) and ventricular fibrillation (VF) are the most common arrhythmias documented at the time of resuscitation in survivors of out-of-hospital cardiac arrest unassociated with an acute myocardial infarction. However, 20% and 40% of these patients will not manifest inducible ventricular arrhythmias during subsequent electrophysiologic studies. The optimal management of these patients has been controversial. ⋯ In four patients, bradyarrhythmias (sinus arrest two; atrioventricular block two) preceded and caused the episode of VF. Therapy directed at these nonventricular arrhythmias prevented recurrence of cardiac arrest in all patients. In survivors of out-of-hospital cardiac arrest, nonventricular arrhythmias represent a treatable potential etiology that may be overlooked during the patient's evaluation.
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American heart journal · Mar 1989
The effect of drugs and lead maturation on atrial electrograms during sinus rhythm and atrial fibrillation.
Antitachycardia devices need more accurate means to identify arrhythmias. Previous studies have found that sinus rhythm can be distinguished from a variety of tachyarrhythmias by algorithms that are based on time-domain and frequency-domain analysis of intracardiac electrograms. Amplitude distribution analysis (time-domain) and power density spectral analysis (frequency-domain) are two of the techniques that have seemed to hold promise. ⋯ Isoproterenol, lidocaine, verapamil, and propranolol had no consistent effects on amplitude distribution analysis of atrial electrograms during sinus rhythm or atrial fibrillation. However, there were marked effects of drugs on amplitude distribution characteristics in individual dogs. Propranolol and lidocaine produced consistent changes in power density spectra during sinus rhythm and atrial fibrillation, respectively; both drugs reduced the ability of power density spectral analysis to differentiate sinus rhythm from atrial fibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)
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American heart journal · Feb 1989
Flecainide acetate in the treatment of supraventricular tachycardias: value of programmed electrical stimulation for long-term prognosis.
Twenty patients with recurrent symptomatic supraventricular tachycardia were studied to estimate the efficacy of flecainide in the long-term treatment of these arrhythmias and to evaluate the prognostic value of programmed electrophysiologic stimulation. All patients had their arrhythmia inducible at baseline evaluation. Nine patients had a Wolff-Parkinson-White (WPW) syndrome, five had a concealed bypass tract, and two had dual atrioventricular (AV) nodal pathways. ⋯ We conclude that flecainide prevents recurrences of supraventricular tachycardias in 65% of patients with inducible supraventricular tachycardias during a mean follow-up of 11 months. Programmed electrical stimulation has a high negative predictive value in this setting. Flecainide is especially effective in preventing atrial fibrillation in patients with WPW syndrome.
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American heart journal · Nov 1988
The epidemiology of the postpericardiotomy syndrome: a common complication of cardiac surgery.
PPS is a major cause of morbidity after cardiac surgery and may cause bypass graft closure and fatal cardiac tamponade. Little is known about its incidence and cause. To better define this syndrome characterized by postoperative fever, pericardial friction rub, and pericardial pain, we used two out of three of the preceding criteria to diagnose PPS. ⋯ The incidence was increased in younger patients, in those with a history of prednisone use in the past, in patients with a past history of pericarditis, those with aortic valve replacement, and in patients who received enflurane or halothane anesthesia. PPS is a common syndrome. Knowledge of risk factors associated with PPS may allow its prevention and identification of patients who warrant early and aggressive treatment.
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Mobitz type II second-degree block manifests with several consecutive impulses conducted with a constant conduction time that are followed by block. This study reflects an entirely new concept of the Mobitz type II phenomenon, wherein consecutive impulses have constant conduction times, but instead of being followed by a block of conduction, are in fact followed by a conduction delay. ⋯ The recognition of this manifestation at the sinoatrial junction is suggested when, during regular sinus rhythm with manifest episodes of Mobitz type II sinoatrial block, the sinus rhythm is at times also complicated by a sudden unexpected prolongation of a P-P interval, which is followed by an shortened P-P interval. This new phenomenon is termed by Mobitz type II delay.