Nine patients with complete heart block and Stokes-Adams disease were treated with subcutaneously implanted, fixed-rate, artificial cardiac pacemakers. All of these patients were refractory to medical treatment and confined to bed by the frequency of their attacks. One patient died in uremia one month after operation; in the remaining eight, the implanted pacemakers are providing adequate stimulation at present. These patients are free of seizures and show an improvement in the amount of their physical activity. A fixed rate of 60 to 65 per minute was adequate in all cases. The results of our clinical experience with cardiac pacemakers is satisfactory, but the possibility of mechanical failure limits their use to situations in which the patient is incapacitated despite medical treatment. (+info)
THE ARTIFICIAL CARDIAC PACEMAKER. INDICATIONS FOR IMPLANTATION.
(10/27)
Extensive clinical experience has demonstrated that implantable cardiac pacemakers are safe and effective mechanisms for controlling symptoms and preventing the hazards of third degree heart block with Stokes-Adams syncope. Medical management of this disease does not provide reliable protection and life expectancy averages about two years after diagnosis. Hence the negligible surgical morbidity and mortality associated with pacemaker implantation justifies broad indications to implant one of the four commercially available battery-powered units. ELECTIVE IMPLANTATION OF A PACEMAKER SHOULD BE CONSIDERED IN PATIENTS WITH PERSISTENT THIRD DEGREE HEART BLOCK WHO HAVE HAD: One or more episodes of Stokes-Adams syncope; surgical injury to the conduction system, regardless of syncopal attacks; evidence of low cardiac output with cardiomegaly secondary to bradycardia. Few if any other cardiac arrythmias are satisfactorily controlled by an electrical pacemaker. Emergency pacemaker control is obviously necessary for patients developing intractable or recurrent bouts of asystole. During the interval until an implantable unit can be obtained and sterilized, the patient may be controlled by intravenous isoproterenol or by an external pacemaker attached to a transvenous catheter electrode, a precordial skin electrode or a percutaneous myocardial wire electrode. (+info)
Monophasic action potential duration at the crista terminalis in patients with sinus node disease.
(11/27)
BACKGROUND: The repolarization properties of the crista terminalis (CT) cells have not been elucidated in patients with sinus node disease (SND). In the present study a new technique of recording the monophasic action potential (MAP) at the CT was used to examine the repolarization of the right atrium (RA) in SND patients. METHODS AND RESULTS: Symptomatic SND (n=13) patients and age-, sex-matched control patients (n=13) were tested. The MAP duration (MAPD) at a basic cycle length of 600 ms was recorded at the CT in the superior vena cava - RA junction and at the middle - anterior RA with the effective refractory period (ERP) at the high RA. In 6 controls and 4 SND patients, the effect of adenosine triphosphate on the MAPD was examined. The MAPD at the CT exceeded that at the middle - anterior RA in both groups. The MAPD at the CT in the SND group was significantly prolonged compared with the control group (CT: 358+/-39 ms vs 289+/-43 ms). Between the SND and control groups, the MAPD at the middle - anterior RA (278+/-36 ms vs 265+/-39 ms) and ERP (294+/-42 ms vs 266+/-41 ms) did not differ. Both the corrected-sinus node recovery time and sinoatrial conduction time were better correlated with the MAPD at the CT than the MAPD at the middle - anterior RA and ERP. Adenosine triphosphate shortened the MAPD, which was augmented at the CT in the SND patients. CONCLUSION: A novel method of estimating the MAP at the CT revealed the characteristics of atrial repolarization in SND patients. (+info)
Hemiblocks revisited.
(12/27)
The trifascicular nature of the intraventricular conduction system and the concept of trifascicular block and hemiblock were described by Rosenbaum and his coworkers in 1968. Since then, anatomic, pathological, electrophysiological, and clinical studies have confirmed the original description and scarce advances have been developed on the subject. In the present study, we attempt to review and redefine reliable criteria for the electrocardiographic and vectorcardiographic diagnosis of left anterior and posterior hemiblock. One of the most important problems related to hemiblocks is that they may simulate or conceal the electrocardiographic signs of myocardial infarction or myocardial ischemia and may mask or simulate ventricular hypertrophy. Illustrative examples of these associations are shown to help the interpretation of electrocardiograms. The incidence and prevalence of the hemiblocks is presented based on studies performed in hospital patients and general populations. One of the most common causes of hemiblocks is coronary artery disease, and there is a particularly frequent association between anteroseptal myocardial infarction and left anterior hemiblock. The second most important cause is arterial hypertension, followed by cardiomyopathies and Lev and Lenegre diseases. The hemiblocks may also occur in aortic heart disease and congenital cardiopathies. Left anterior hemiblock is more common in men and increases in frequency with advancing age. Evidence is presented regarding the relationship of spontaneous closure of ventricular septal defects, which may explain the finding of this and other conduction defects in young populations. Isolated left anterior hemiblock is a relatively frequent finding in subjects devoid of evidence of structural heart disease. Conversely, isolated left posterior hemiblock is a very rare finding; its prognostic significance is unknown and is commonly associated with right bundle-branch block. The most remarkable feature of this association is that the prognosis is much more serious with a great propensity to develop complete atrioventricular block and Adams-Stoke seizures. (+info)
Aubrey Leatham and the introduction of cardiac pacing to the UK.
(13/27)
Acute inflammatory demyelinating polyradiculoneuropathy presenting as complete heart block and Stoke-Adams attacks.
(15/27)
A patient with acute inflammatory demyelinating polyradiculoneuropathy (AIDP, Guillain-Barre syndrome) whose presenting complaints were related to autonomic dysfunction in the form of parasympathetic and sympathetic overactivity is reported. Parasympathetic overactivity was severe enough to cause complete atrioventricular block (atropine-responsive) and Stoke-Adams attacks, for which a demand pacemaker was required. Limb weakness was apparent 48 hours later. To our knowledge no such presentation of AIDP has been previously recorded. (+info)
Treatment of glossopharyngeal neuralgia by carbamazepine.
(16/27)
An elderly woman who presented with Adams-Stokes attacks that were preceded by paroxysms of neuralgia was successfully treated with carbamazepine. Ventricular asystole was provoked by pharyngeal pain and coincided with loss of consciousness. Vagal reflexes are probably responsible for the bradycardia that causes the cardiac symptoms of glossopharyngeal neuralgia. Carbamazepine (600 mg/day) abolished the pharyngeal pain and associated cardiovascular manifestations in this patient for at least ten months. (+info)