Clinical cardiology
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We studied the possibility that intravenous nitroglycerin may produce heparin resistance both in vitro and prospectively in a group of 10 patients following coronary angioplasty. Nitroglycerin in physiologic to pharmacologic concentrations (41-250 micrograms/ml) did not produce heparin resistance in vitro as measured by activated partial thromboplastin time and thrombin time. ⋯ In patient studies, the activated partial thromboplastin time at baseline on heparin alone (93 + 22 s) was not significantly different (p = 0.61) from activated partial thromboplastin measured upon addition of nitroglycerin (94 +/- 27 s) or 30 min following cessation of the nitroglycerin infusion while continuing the same dose of heparin (91 +/- 24 s). We conclude that intravenous nitroglycerin does not induce heparin resistance in vitro or in patients during short-term administration.
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Clinical cardiology · Jun 1989
Randomized Controlled Trial Comparative Study Clinical TrialTocainide and metoprolol: an efficacious therapeutic combination in the treatment of premature ventricular beats.
A double-blind crossover study was performed in 20 patients to verify the efficacy of tocainide plus metoprolol in patients with premature ventricular contractions (PVCs) class Lown greater than or equal to 2 (mean frequency greater than or equal to 30/h) judged as being "stable" by at least three basal 24-h Holter ECGs with PVC variation of less than +/- 25%. All 20 patients were submitted to a placebo period; and all were subsequently randomized to therapy with tocainide 1800 mg/day or metoprolol 200 mg/day for 15 days and then to tocainide 1800 mg + metoprolol 200 mg/day or tocainide 1200 mg + metoprolol 200 mg/day for 15 days, followed by a crossover of the two combination treatments. At steady state in every stage we controlled for plasma levels of the drugs, a 24-h Holter recording, and a 12-lead ECG. ⋯ Administration of tocainide 1200 mg + metoprolol 200 mg obtained a positive response in 9 of 12 patients, the modified Lown score decreased significantly compared with placebo (from 53 +/- 31 to 32 +/- 30, p less than 0.01) and Lown 4B arrhythmias were abolished in 2 of 5 cases. Tocainide 1800 mg plus metoprolol 200 mg was scarcely tolerated owing to neurologic and gastroenteric side effects, and only three patients completed this stage with no better antiarrhythmic results compared to the lower dose. In conclusion, the combination of tocainide at 1200 mg and metoprolol 200 mg is well tolerated, efficacious in a high percentage of patients, and superior to single drug therapy in patients with stable PVCs.
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Clinical cardiology · Dec 1988
Heart rate, PR, and QT intervals in normal children: a 24-hour Holter monitoring study.
A dynamic electrocardiographic Holter monitoring study was performed in 32 healthy children (20 males and 12 females, age range 6-11 years old), without heart disease, according to clinical and noninvasive instrumental examination. We evaluated atrioventricular conduction time (PR), heart rate (HR), and QT interval patterns defining the range of normality of these electrocardiographic parameters. The PR interval ranged from 154 +/- 10 ms (mean +/- SD) for HR less than or equal to 60 to 102 +/- 12 ms for HR greater than or equal to 120 (range 85-180). ⋯ Daytime mean HR gave a mean value of 93 +/- 10 (range 71-148), while during night hours it was 74 +/- 11 (range 54-98). The minimum QT interval averaged 261 +/- 10 ms for HR greater than 120 and the maximum 389 +/- 9 ms for HR less than or equal to 60; the corresponding mean value of QTc (i.e., QT corrected for HR) ranged from 388 +/- 8 for HR less than or equal to 60 beats/min to 403 +/- 14 ms for HR greater than 120 beats/min. The results of the present study provide data of normal children which can be readily compared against those of subjects in whom cardiac abnormalities are suspect or patient.(ABSTRACT TRUNCATED AT 250 WORDS)
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This case describes a 69-year-old male who had a permanent pacemaker implanted for sick sinus syndrome. He was struck by a car with a resultant failure of the pulse generator. Trauma-related failure of a pulse generator is a rare event. Its recognition is imperative in the overall management of the trauma patient.
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Clinical cardiology · Jun 1988
Etiology and prognostic implications of a large pericardial effusion in men.
To assess the etiology and prognosis of a large pericardial effusion, we reviewed 25 consecutive patients who presented with a large pericardial effusion and underwent a drainage procedure. Large pericardial effusion was defined as: (1) an echo-free space greater than or equal to 10 mm anteriorly and posteriorly by M-mode echocardiography and (2) removal of greater than or equal to 350 ml of fluid at pericardial drainage. The etiologies of large pericardial effusion were: neoplastic (36%), idiopathic (32%), uremic (20%), postmyocardial infarction (8%), and acute rheumatic fever (4%). ⋯ While 88% of patients with idiopathic large pericardial effusion were alive at follow-up, none of the neoplastic large pericardial effusion patients survived longer than 5 months after initial pericardial drainage (p less than 0.001). Additionally, the survival of patients with uremic large pericardial effusion was better than patients with neoplastic large pericardial effusion (p less than 0.05). We conclude: (1) neoplastic, idiopathic, and uremic pericarditis are the most common causes of large pericardial effusion in men, (2) idiopathic pericarditis can be hemorrhagic and cause cardiac tamponade, and (3) the prognosis of large pericardial effusion is related to patients' underlying disease.