The American journal of cardiology
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William Osler (1849-1919) was generally regarded as the greatest and most respected physician of his time. He is still considered by many in these terms. Others have questioned the relevance of Osler's teachings in recent years. ⋯ Osler's wisdom is as relevant now as in his era. It is likely that he would be in the forefront of medical science if he were alive today. Osler blended the art and science of medicine perhaps better than anyone else and remains a valuable role model for students and physicians more than 75 years after his death.
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Multicenter Study Clinical Trial Controlled Clinical Trial
Safety and efficacy of intravenous diltiazem in atrial fibrillation or atrial flutter.
This study examines the efficacy of various doses of intravenous diltiazem to control the ventricular response during atrial fibrillation or atrial flutter. Control of the ventricular response of patients with atrial fibrillation and a rapid ventricular response can provide patients with relief of symptoms and improve hemodynamics. Eighty-four consecutive patients with atrial fibrillation or atrial flutter, or both, received an intravenous bolus dose of diltiazem followed by a continuous infusion of diltiazem at 5, 10, and 15 mg/hour. ⋯ After 10 hours of infusion, 47% of patients (confidence interval [CI]: 36%, 59%) had maintained response with the 5 mg/hour infusion, 68% (CI: 57%, 79%) maintained response after the infusion was titrated to 10 mg/hour, and 76% (CI: 66%, 85%) after titration from the 5 and 10 mg/hour infusion to the 15 mg/hour dose. For the 3 diltiazem infusions studied, mean (+/- SD) heart rate was reduced from a baseline value of 144 +/- 14 beats/min to 98 +/- 19, 107 +/- 25, 107 +/- 22, 101 +/- 22, 91 +/- 17, and 88 +/- 18 beats/min at infusion times 0, 1, 2, 4, 8, and 10 hours, respectively. By the end of the infusion, 18% of patients (14 of 78) had conversion to sinus rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)
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A prolonged rate-corrected QT interval (QTc) may be associated with an increased risk of developing ventricular arrhythmias and sudden death, particularly in patients with the hereditary long QT syndrome (LQTS), myocardial ischemia, or antiarrhythmic medication toxicity. It is known that there are some patients with LQTS who sometimes have a borderline or normal QTc (< or = 0.45 second). Although the QTc has been the standard measurement of ventricular repolarization, it includes both depolarization and repolarization and may not always be a sensitive indicator of the type of repolarization abnormalities seen in LQTS. ⋯ The JTc identified 85% of patients affected with LQTS compared with only 58% identified using only the QTc as a marker for the syndrome. The JTc is a more specific measurement of ventricular repolarization than the QTc by eliminating QRS duration variability. It appears to be a more sensitive predictor of repolarization abnormalities, and may be helpful in identifying patients with LQTS who have borderline or normal QTc measurements on resting electrocardiograms.
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Comparative Study Clinical Trial
Usefulness of a third Holter lead for detection of myocardial ischemia.
Two-channel ambulatory electrocardiographic (ECG) monitoring is a useful method for detecting transient myocardial ischemia in patients with coronary artery disease. However, the monitoring of only 2 leads may fail to detect a significant number of ischemic episodes. In this study, the additional diagnostic value of a third bipolar chest lead was evaluated by recording a simultaneous 12-lead electrocardiogram and a 3-channel ambulatory electrocardiogram during exercise testing in 223 patients (aged 63 +/- 10 years) with proved or suspected coronary disease. ⋯ CM5 was the single lead with the highest sensitivity (89%) in detecting myocardial ischemia. The addition of CM3 to CM5 increased sensitivity to 91%, and the addition of an inferior lead to CM5 increased sensitivity to 94%, particularly improving the detection of isolated inferior myocardial ischemia. The combination of all 3 ambulatory ECG leads had a sensitivity of 96%, an improvement of only 2% compared with the best combination of 2 leads (i.e., CM5 +/- inferior lead).(ABSTRACT TRUNCATED AT 250 WORDS)
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In 17 patients (14 men and 3 women aged 69 +/- 10 years), a transvenous pacemaker was implanted before (8 patients), following (7 patients), or simultaneously (2 patients) with the insertion of a transvenous defibrillator. Indications included malignant ventricular arrhythmias and symptomatic bradycardia in all patients. All patients had structural heart disease. ⋯ During a mean follow-up of 11 +/- 6 months, 2 patients died because of pump failure and 7 patients received defibrillator therapy for ventricular arrhythmias. No significant complications were noted. Successful concomitant implantation of transvenous pacemakers and defibrillators was thus accomplished in 17 patients, which suggests that insertion of a second transvenous device can be safely accomplished.