American heart journal
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American heart journal · Aug 1991
Comparative StudyIndices of reperfusion in patients with acute myocardial infarction using characteristics of the CK-MB time-activity curve.
The purpose of this study was to identify indices of coronary artery reperfusion in patients treated with thrombolytic therapy for acute myocardial infarction (AMI) by means of characteristics from the serum creatine kinase (CK) isoenzyme MB time-activity curve. Frequent blood sampling as performed in three groups with a first AMI: 29 patients treated with intravenous thrombolytic therapy who had a patent infarct-related artery with normal flow (TIMI-3) at acute catheterization (reperfusion group); four patients with a persistently closed infarct-related artery (no reperfusion group); and 44 patients who did not receive any therapy aimed at coronary reperfusion (no thrombolytic therapy group). ⋯ In addition to demonstrating an earlier increase, a shorter time to peak of serum CK-MB and a lower estimated infarct size in the reperfusion group (p = 0.025 to 0.00001), the appearance rate constant (k1) and time from estimated initial increase to peak of CK-MB in the blood stream (tRP) were significantly different from those values in the no thrombolytic therapy group (p less than 00001). A cutoff level indicating reperfusion if k1 was greater than 0.185 or tRP was less than 16.5 hours demonstrated overlapping values between these two groups in only four patients (k1), two patients (tRP), and six patients with a combination.(ABSTRACT TRUNCATED AT 250 WORDS)
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American heart journal · Aug 1991
Comparative StudyCollateral circulation as a marker of the presence of viable myocardium in patients with recent myocardial infarction.
The relationship between the presence of viable myocardium and the extent of coronary collateral circulation to the infarct area was evaluated in 20 patients with a recent anterior myocardial infarction who had complete obstruction of the left anterior descending coronary artery. The viability of myocardial tissue was assessed by exercise thallium-201 myocardial scintigraphy, and the collateral circulation was angiographically evaluated by means of a collateral index ranging from 0 to 3. ⋯ The collateral index in group 1 was 2.5 +/- 0.5 (SD), which was significantly higher than the 0.7 +/- 0.8 in group 2. These findings indicate that the presence of ischemic but viable myocardium is intimately related to the development of collateral circulation in patients with myocardial infarction, and the existence of well-developed collateral channels predicts the presence of viable myocardium in the infarct area.
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American heart journal · Jun 1991
Multicenter Study Clinical TrialEffects of variable dose milrinone in patients with low cardiac output after cardiac surgery. European Multicenter Trial Group.
We studied 99 adult patients after elective cardiac surgery who had low cardiac output (cardiac index less than 2.5 L/min/m2) in spite of adequate cardiac filling pressure (pulmonary capillary wedge pressure less than 8 mm Hg). Patients received milrinone by loading dose (50 micrograms/kg over a 10-minute period), followed by a continuous infusion of either 0.375, 0.5, or 0.75 micrograms/kg/min (low-, middle-, and high-dose groups, respectively) given for a minimum of 12 hours. Patients were allocated to each dosage group sequentially, not randomly. ⋯ Systemic and pulmonary vascular resistance also fell significantly, although changes in this latter parameter were less predictable and more dose dependent. Few serious treatment-related adverse effects were seen. We conclude that intravenous milrinone is an effective and safe therapy for the treatment of low output states after cardiac surgery.