Sudden Wenckebach Periods and Their Relationship to Neurocardiogenic Syncope

Throughout a 9-month period during which 1, 125 Hoiter tapes were reviewed prospectively we identified 13 non medicated patients with an arrhythmia, which for the purposes of this presentation was categorized, because of their mode of initiation, as sudden Wenckebach periods (WP). The episodes emerged abruptly from a normal (± 200 ms) PR interval with sudden prolongation of PR and PP intervals (and reversed PR-RP relationship that took place over 1–8 cycles. The postpaced PR interval was shorter than that of the last conducted beat. The episodes were separated into two groups. Group I included 11 patients with symptoms other than syncope and Group 11 included 2 patients with syncope. There were 26 episodes of sudden WP in Group 1. Twenty-five terminated in a single (and one in double) blocked P waves. Most episodes occurred between 10 PM and 7 AM. Symptoms did not correlate with the episodes. Mean 24-hour rates were < 90. In Group II there were 22 episodes, all occurring between 6 AM and 10 PM. The mean sinus cycle lengths before the phenomenon started to occur in Group I (861 ± 185 ms) as well as the cycle lengths at the onset of block (1,096 ± 215 ms) were statistically longer than those in Group II (591 ± 40 ms and 747 ± 63 ms, respectively, P < 0.0001). Although the mode of onset in the episodes in Group II was similar to Group I, 16 episodes terminated in 2–6 blocked P waves. Thus, the entire number of episodes could be categorized as an unusual type (because of the PR prolongation) of paroxysmal, or advanced second degree A V block. Because these patients had negative electrophysiological studies, positive tilt tests, and absent syncope after oral propranolol therapy, they were considered as having neurocardiogenic syncope. In addition, the faster than normal (> 100) mean 24-hour rates) suggested that they also had so-called inappropriate sinus tachycardia. In summary. Group I consisted of patients with a normal, benign, vagal-induced second-degree AV block, whereas the Hoiter findings in Group II appeared to refiect unusual (but natural, i.e., nonprovoked) electrocardiographic manifestations of certain patients with neurocardiogenic syncope.     

Instrumentation for the Follow-Up of Pacemade Patients

Logic circuitry has been added to an electrocardiogram telephone transmitter. It processes the electrocardiogram and permits frequent self-checks by the patient on rate, capture and sensing function of an implanted demand pulse generator system. Correct function is communicated to the patient by a green light. Malfunction with regard to any of these parameters produces an irreversible yellow light signaling the patient to contact his physician. The self-check is reassuring to the patient during intervals between visits to the physician's office or a specialized clinic. The system, at present, is applicable only to demand pulse generators with a high magnet test rate (90 ppm or higher) which assures capture in virtually all patients. This and other limitations are discussed. Their incidence is low, some can be remedied and in the majority of patients they do not impair the clinical usefulness of the system.     

Major Histocompatibility Antigens on Trophoblast and Their Regulation: Implications in the Maternal-Fetal Relationship

ABSTRACT: Recent technological advances have provided methods of detecting antigens encoded by the major histocompatibility complex with greater precision, allowing the expression of such antigens on the components of the placenta to be clarified. Of specific interest is the expression of these antigens on trophoblast cells, the fetal-derived epithelial cells that confront maternal blood and tissues at the maternal-fetal interface. It is now clear that the different trophoblast subpopulations differentially express class I antigens, although none appear to express class II antigens. Class I antigens can be induced by exposure to interferons on some populations but apparently not others, suggesting that the regulation of their expression differs for sub-populations of trophoblast cells, depending on gestational stage and location. This restricted expression has important implications for maternal-fetal immune interactions during the different phases of pregnancy and perhaps also bears on physiological functions of the feto-placental unit, such as growth and differentiation.     

Efficacy of Acupuncture in Preventing Atrial Fibrillation Recurrences After Electrical Cardioversion

Antiarrhythmic Effect of Acupuncture . Introduction: In traditional Chinese medicine, stimulation of the Neiguan spot has been utilized to treat palpitations. We evaluated whether acupuncture might prevent or reduce the rate of arrhythmia recurrences in patients with persistent atrial fibrillation (AF). Methods and Results: We studied 80 patients with persistent AF after restoring sinus rhythm with electrical cardioversion. Twenty‐six subjects who were already on amiodarone treatment constituted the AMIO reference group. The remaining patients were randomly allocated to receive acupuncture (ACU group, n = 17), sham acupuncture (ACU‐sham group, n = 13), or neither acupuncture nor antiarrhythmic therapy (CONTROL group, n = 24). Patients in the ACU and ACU‐sham groups attended 10 acupuncture sessions on a once‐a‐week basis. Only in the former group the Neiguan, Shenmen, and Xinshu spots were punctured. During a 12‐month follow‐up, AF recurred in 35 patients. Cumulative AF recurrence rates in the AMIO, ACU, ACU‐sham, and CONTROL patients were 27%, 35%, 69%, and 54%, respectively (P = 0.0075, log‐rank test). Ejection fraction (P = 0.0005), hypertension (0.0293), and left atrial diameter (P = 0.0361) were also significantly associated with AF recurrence. Compared with AMIO group, recurrence rate was similar in ACU patients (hazard ratio: 1.15, 95% CI: 0.38–3.49; P = 0.801) but significantly higher in ACU‐sham and CONTROL patients (3.77, 1.39–10; P = 0.009 and 3.15, 1.23–8.06; P = 0.017, respectively) after adjustment for ejection fraction, hypertension, and left atrial diameter using Cox modeling. Conclusion: Our data indicate that acupuncture treatment prevents arrhythmic recurrences after cardioversion in patients with persistent AF. This minimally invasive procedure was safe and well tolerated. (J Cardiovasc Electrophysiol, Vol. 22, pp. 241‐247, March 2011)     

Management of Pacing System Related Complications in Patients Undergoing Dynamic Cardiomyoplasty

Integrity of the electrical circuit is a necessary requirement for appropriate heart/wrapped skeletal muscle interaction to be achieved in cardiomyoplasty. This article describes the management of two different complications after a cardiomyoplasty procedure involving the electrical system (infection of the abdominal cardiomyostimulator pocket and intramuscular lead fracture). Minimal approaches were carried out, which ensured the successful treatment of the infective and of the mechanical insult, and represent useful strategy for solving such uncommon problems.