摘要:

A total of 73 noninvasive serial electrophysiological studies were carried out in 12 patients with spontaneous sustained ventricular tachycardia, inducible in spite of chronic treatment with amiodarone, in order to verify the effect of this drug on the long‐term reproducibility of the test. A ventricular tachycardia was induced in 72 of 73 times; in 59% of cases, the clinical form was induced. In 8 of 12 patients, two or more types or morphologies of ventricular tachycardia could be induced. The induction modes (driving rate and number of extrastimuli) changed considerably in different studies. During a follow‐up of 12 ± 6 months, 5 out of 12 patients had spontaneous relapses. We observed no differences between these patients and the others regarding inducibility, types and morphologies of the induced tachycardias, or induction modes. Therefore, when ventricular tachycardia is inducible in spite of chronic amiodarone therapy, it is always inducible during follow‐up, even if a great intrapatient change of type and the morphology of induced tachycardias and induction modes is observed. However, since similar electrophysiological features are present in patients with and without spontaneous recurrence of ventricular tachycardia, serial electrophysiological studies are of little value in predicting the clinical o

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01710.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Common Opioid Actions in Pain and Cardiovascular Stress Responses.This overview describes three parallel aspects of the architecture and function of opioid action in nociceptive and cardiovascular spheres. First, in both circumstances, opioid secretion and receptor activation are essentially dormant during basal conditions and assume physiological importance only during stress. Second, in either context, opioids produce their responses by activating complementary mechanisms centrally and in the periphery. Third, endorphins act as “neuromodulators” of either type of response through a typical cellular architecture in which they diminish underlying excitatory neurotransmiss

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01367.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Incidence of sudden death and arrhythmia pattern were studied using ambulatory monitoring in 40 patients resuscitated<24 hours (n = 26, Group I) or 4–12 weeks (n = 14, Group II) after myocardial infarction. Forty patients with myocardial infarction and no resuscitation served as controls (Group III). Ambulatory ECGs were recorded with an average of 2 months (Recording 1) and 28 months (Recording 2) after myocardial infarction. Incidence of sudden death was significantly higher in Group II (43%) than in Group I (15%) or Group III (8%) (p<0.01). In Recording 1, there were no significant differences in the incidence of premature ventricular beats and complex arrhythmias (couplets or salvos) between survivors and sudden death patients in Groups I, II and III, whereas in Recording 2 the mean incidence of premature ventricular beats and complex arrhythmias was significantly higher in survivors in Group II than in Group I or Group III (p<0.05). In addition, in survivors in Group II, incidence of premature ventricular beats and complex arrhythmias was significantly higher in Recording 2 than in Recording 1 (p<0.05). Our data show that the risk of sudden death is high in patients with cardiac arrest 4–12 weeks after myocardial infarction. Repeated studies using ambulatory monitoring are helpful in estimating the risk of sudden death in patients with myocardial infarction and cardiac arr

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01711.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Narcotics as Anesthetics.Production of profound analgesia (“narcotic anesthesia”) without hemodynamic deterioration is easily and reliably achieved in patients with compromised cardiovascular systems by intravenous administration of large doses of opioids. Even extremely high plasma levels of opioids alone often fail to prevent hypertensive responses to anesthetic and surgical stimulation. It has not been possible to define a blood level of the narcotic that is consistently associated with prevention of hemodynamic or hormonal responses. Since some of the interventions that are associated with hemodynamic and hormonal responses are probably not painful per se, the hemodynamic and hormonal responses may not represent inadequate “anesthesia,” as it is usually defined. Different narcotics have different systemic and neurally mediated effects upon muscle vascular resistance. Local infusion of morphine produces a decline in vascular resistance, whereas local infusion of sufentanil does not. Intravenous administration of morphine is associated with a transient neurally mediated, passive decline in muscle vascular resistance that appears to be due to central sympatholysis, and a persistent neurally mediated increase in muscle vascular resistance. Sufentanil actively dilates muscle vasculature by a neural mechanism. Since the latter may be blocked by localα1‐adrenergic blockade or by the combination of local H1 and H2 blockers, we interpret these data to indicate that a local histaminergic system in the blood vessel walls is activated by withdrawal ofα1‐adrenergic activity, possibly related to anα2agonist action of sufentanil at central nervous sy

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01368.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Torsade de pointer is often associated with syncope, particularly when prolonged. We report a cane of prolonged asymptomatic torsade de pointes in a 68‐year‐old woman being treated with quinidine gluconate for paroxysmal atrial fibrillation. Ambulatory monitoring obtained one week after an increase in the daily qninidine dosage demonstrated one minute of polymorphous ventricular tachycardia. The patient remained entirely asymptomatic throughout the time of the arrhythmia. Therefore, a lack of symptoms in patients at risk for torsade de pointes may not exclude the presence of this arrhyth

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01712.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Opiate Blunting of Perioperative Stress Responses in Infants.Integration of nociceptive pathways and cardiovascular control centers in the neonatal brain stem are quite well developed as demonstrated by marked hormonal, metabolic, and cardiovascular responses to painful and stressful stimulation. During surgical procedures, the hormonal and metabolic responses to pain are extreme in the neonate and may be deleterious. Increases in levels ofβ‐endorphins, catecholamines, growth hormone, cortisol, and glucagon in neonates during major surgical procedures are greater than those seen in adults. These increased levels produce a substantial catabolic drive intraoperatively and postoperatively characterized by increased levels of oxygen consumption, glucose, lactate, pyruvate, tissue glycogen, and protein metabolism that are poorly tolerated by the fragile neonate. In contrast to other anesthetic agents, these extreme hormonal and metabolic stress responses to surgically‐induced pain can be at least partially attenuated by high‐dose opiates. Such high‐dose opiates have additional benefits such as increases in the threshold for ventricular fibrillation, but opiates also produce marked respiratory depression requiring a period of mechanical ventilation. In addition, high‐dose opiates blunt pulmonary vascular reactivity and decrease pulmonary hypertensive crises in infants with pulmonary hypertension. Further understanding of the integration of pain and cardiovascular responses in the neonate is needed to further improve our abilities to control thes

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01369.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

The preferred pacing therapy for symptomatic bradycardia incorporates rate responsiveness. The hemodynamic benefits of rate responsiveness have been established. Factors such as type of sensors, reliability, and ease of utilization play a role in the selection of the best‐suited rate‐responsive system for the individual pati

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01713.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Antinociception and Hypertension.A review of available data indicates that acute and chronic increases in arterial blood pressure (ABP) are associated with antinociception in animals and hypoalgesia in humans. The primary issues of concern are whether increases in ABP are directly responsible for altered nociceptive function, and the extent to which carotid sinus, aortic depressor, and/or vagal afferents contribute to the changes in nociceptive function.

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01370.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Part IV: Class II, Class III, and Class IV antiarrhythmic drugs, comparative efficacy of drugs, and the effect of drugs on mortality — review of their pharmacokinetics, efficacy, and toxicity. This part reviews the Class II antiarrhythmic agents that share the property of beta adrenergic antagonism, but include several drugs with other unique features. Also reviewed are the Class III agents, which prolong the action potential duration, with a focus on amiodarone. The Class IV agents, which antagonize the calcium channel, are reviewed. Finally, this part reviews the comparative efficacy of antiarrhythmic agents for treatment of ventricular ectopic depolarizations and examines their effect on mortalit

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01714.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Mental Stress and Coronary Vasomotion.Coronary artery disease often presents late in its course with adverse events like myocardial infarction and sudden death. One of the earlier manifestations of the disease is transient myocardial ischemia. It is clear that physical and mental stress can precipitate ischemic episodes during daily life. Through studies done in the cardiac catheterization laboratory, we found evidence suggesting that mental stress causes an increase in oxygen demand and a decrease in blood supply by causing vasoconstriction of the atherosclerotic epicardial coronary arteries. Local factors like endothelial dilator function may play a significant role in the vasomotor response to mental stress.

ISSN:1045-3873    

DOI:10.1111/j.1540-8167.1991.tb01371.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY