The American journal of cardiology
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Comparative Study Clinical Trial Controlled Clinical Trial
Comparison of intravenous anisoylated plasminogen streptokinase activator complex and intracoronary streptokinase in acute myocardial infarction.
Coronary angiography was used to compare the efficacy of anisoylated plasminogen streptokinase activator complex (APSAC) administered intravenously and streptokinase given by intracoronary infusion in inducing reperfusion in patients with a proven acute myocardial infarction. Forty-two patients received 30 U of APSAC intravenously over 5 minutes and 43 patients received 250,000 IU of streptokinase given via intracoronary infusion over 90 minutes, after occlusion of the infarct-related vessel was demonstrated by angiography. Reperfusion was achieved in 23 (64%) of 36 patients (mean time to reperfusion 46 minutes) treated with APSAC and 25 (67%) of 37 patients (mean time to reperfusion 45 minutes) treated with intracoronary streptokinase, who were angiographically evaluated 90 minutes after the start of treatment. ⋯ Two patients treated with APSAC died after severe left ventricular failure unrelated to therapy. The results indicate that APSAC given intravenously is as effective as streptokinase given intracoronary in producing thrombolysis in acute myocardial infarction. The major advantages of APSAC are its rapid and convenient administration by a single intravenous injection, the low rate of arterial reocclusion and good patient tolerance.
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Thirty-eight patients (24 men and 14 women) with an acquired ventricular septal defect during acute myocardial infarction (AMI) (rupture group) were studied and their clinical and necropsy findings were compared with 50 patients who died during their first AMI without rupture (nonrupture group). The frequency of systemic hypertension (54 vs 52%), angina pectoris (28 vs 22%) and congestive heart failure (5 vs 0%) before the fatal AMI was similar for both rupture and nonrupture groups. Mean heart weights for men (498 vs 526 g) and women (397 vs 432 g) with and without septal rupture also were insignificantly different. ⋯ The rupture group had a significantly more frequent (p less than 0.01) posterior location of the infarcts (74 vs 40%) and, therefore, a higher frequency of associated right ventricular infarcts 50 vs 18%). The number of 3 major (right, left anterior descending and left circumflex) epicardial coronary arteries narrowed at some point greater than 75% in cross-sectional area of atherosclerotic plaque was the same in both groups. The percent of these 3 arteries totally occluded or nearly so (greater than 95% in cross-sectional area) by plaque was significantly less (p less than 0.001) in the rupture group compared with the nonrupture group (9 of 99 arteries [9%] vs 38 of 144 arteries [26%]).(ABSTRACT TRUNCATED AT 400 WORDS)
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Comparative Study
Immediate quantitation of antiarrhythmic drug effect by monophasic action potential recording in coronary artery disease.
A contact electrode catheter, which permits clinical recording of cardiac monophasic action potentials (MAPs), was used as a means of quantifying the electrophysiologic effect of 2 antiarrhythmic drugs, procainamide and quinidine. MAP recordings were made in continuous fashion from the right ventricle in 16 patients, before and after the intravenous administration of procainamide (11 patients) or quinidine (5). Increases in the MAP duration at 90% repolarization (MAPD90) were used as indexes of drug effect and related to plasma drug level. ⋯ Dose response curves, plotting change in MAPD90 versus plasma drug level, showed strong linear correlation for both procainamide (p less than 0.0001) and quinidine (p less than 0.0001). The variance (error of estimation) of the predictive relation, change in MAPD90 versus plasma drug level, was significantly lower than that of change in QTC (p less than 0.001), QRS duration (p less than 0.0001) or ventricular effective refractory period (p less than 0.0001) versus plasma drug level for both procainamide and quinidine. Changes in MAP duration closely correlate with plasma drug level, and as such, may serve as an immediate, quantitative indicator of myocardial drug effect during the administration of antiarrhythmic agents.
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Induction of ventricular tachycardia (VT) at electrophysiologic study in patients taking amiodarone poorly predicts recurrence of VT. Consequently, a discriminant function was developed (using parameters based on retrospective data) that appeared to identify high-risk patients. These parameters included ventricular effective refractory period, corrected QT interval, initiation of a repetitive ventricular response and the mode of VT induction. ⋯ In contrast, only 4 of 44 (9%) patients who had either the same or harder mode of VT induction had a recurrent event. Overall, 9 of 16 (56%) patients with an easier mode of VT induction had a recurrence, including 6 of the 8 patients with subsequent sudden cardiac death. It is concluded that electrophysiologic testing during amiodarone therapy is useful to identify high-risk patients.
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This study determined whether noninvasive electrical impedance cardiography accurately measures systemic blood flow (cardiac output) in children with congenital heart defects. A total of 37 patients ranging in age from 2 to 171 months underwent complete right- and left-sided heart catheterizations that included simultaneous Fick and impedance measurement of cardiac output. Based on the diagnosis, 4 groups were formed consisting of a control group (n = 11) with no shunts, a group with intracardiac left-to-right shunting and an atrial septal defect (n = 7), another with a ventricular septal defect (n = 12) and an extracardiac left-to-right shunting with patent ductus arteriosus group (n = 7). ⋯ Fick pulmonary blood flow was significantly greater than impedance or Fick systemic flow in all 3 shunt groups. Impedance cardiography accurately measured systemic blood flow in children without shunts or valvular insufficiency. Likewise, systemic blood flow was accurately measured by impedance in the presence of intracardiac left-to-right shunts (atrial and ventricular septal defects) and extracardiac left-to-right shunts (patent ductus arteriosus).(ABSTRACT TRUNCATED AT 250 WORDS)