To the Editor.— I read the interesting article, "Exercise-Induced Arrhythmias in Patients With Pacemakers," by Singer et al, published in The Journal (224:1515, 1973). Myocardial ischaemia, sympathomimetic drugs, and stress such as recent operation are the factors described that such dysrhythmias may occur in patients with pacemakers in the absence of the above precipitating factors.1 In three of my patients, exercise might have induced the dysrhythmias.Dysrhythmias following exercise might well be related to increased circulating catecholamine levels or increased sensitivity of the myocardium to catecholamines, practolol, being a specific, competitive antagonist of catecholamine at beta-receptor sites with a marked selectivity for those in the myocardium,2 would be a useful prophylactic agent for the patients with exercise-induced dysrhythmias after pacemaker implantation. I have demonstrated the efficacy of practolol, and adrenergic beta-receptor related to propranolol, in the treatment of pacemaker-induced dysrhythmias and also suggested its use in dysrhythmia-prone patients
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
Instructions
Comments are moderated and will appear on the site at the discretion of the Journal of American Medical Association editors. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest* Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more
Subscribe for full-text access to content from 1998 forward and a host of useful features
Activate your current subscription (AMA members and current subscribers)
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Customize your page view by dragging & repositioning the boxes below.
and access these and other features:
Register Now
Enter your username and email address. We'll send you a reminder to the email address on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.