SUMMARYWe compared dimensions of the left ventricular minor axis (S) measured at end-

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To evaluate the relative thrombolytic efficacy and complications of intracoronary vs high-dose, short-term intravenous streptokinase infusion in patients with acute myocardial infarction, we performed baseline coronary arteriography and then randomly allocated 51 patients with acute myocardial infarction to receive either intracoronary (n = 25) or intravenous (n = 26) streptokinase. Patients getting the drug by the intracoronary route received 240,000 IU of streptokinase into the infarct-related artery over 1 hr, whereas those getting the drug by the intravenous route received either 500,000 IU of streptokinase over 15 min (n = 10) or I million IU of streptokinase over 45 min (n = 16). Angiographically observed thrombolysis occurred in 76% (19/25) of the patients receiving intracoronary streptokinase, in 10% (1/10) of the patients receiving 500,000 IU of streptokinase intravenously, and in 44% (7/16) of the patients receiving 1 million IU of streptokinase intravenously. Among patients in whom thrombolysis was observed, mean elapsed time from onset of streptokinase infusion until lysis was 31 ± 18 min in patients receiving intracoronary streptokinase and 38 + 20 min in those receiving intravenous streptokinase (p = NS). Among patients in whom intravenous streptokinase "failed," intracoronary streptokinase in combination with intracoronary guidewire manipulation recanalized only 7% (1/15). Fibrinogen levels within 6 hr after streptokinase were significantly lower in the patients receiving intravenous streptokinase (39 ± 17 mg/dl) than the levels in those receiving intracoronary streptokinase (88 + 70 mg/dl) (p < .05) but were similar 24 hr after streptokinase in the two groups. Bleeding requiring transfusion occurred in one patient in each group. Thus, in this prospective randomized trial of intracoronary vs intravenous streptokinase, hemorrhagic complications were few, although both regimens produced a systemic lytic state. Although the thrombolytic efficacy of intracoronary streptokinase was superior to that of high-dose, short-term intravenous streptokinase, the higher-dose intravenous regimen (1 million IU over 45 min) achieved thrombolysis in a significant minority (44%) of patients and might be useful therapy for patients not having access to emergency catheterization.Circulation 68, No. 5, 1051No. 5, -1061No. 5, , 1983 RECENTLY, intracoronary streptokinase has achieved considerable popularity as a means for recanalizing acutely thrombosed coronary arteries in patients with evolving acute myocardial infarction. 1 Unfortunately, emergency coronary arteriography and intracoronary streptokinase infusion require sophisticated equipment and a specially trained operator and

Using angiocardiographic data from 50 human subjects, a comparison was made of calculations of circumferential wall stress in the left ventricle based on the thin-walled ellipsoidal model of Sandier and Dodge and the thickwalled ellipsoidal model of Wong and Rautaharju. The Sandier and Dodge formula consistently overestimated mean stress as determined from the Wong and Rautaharju model. The degree of overestimation in terms of percent error usually varied between 5% and 15% and overall averaged about 10% at endsystole as well as at end-diastole. Analysis of the various factors influencing the discrepancy between calculations indicated that the expected increase in error associated with an increase in wall thickness during systole tended to be mitigated by a concomitant change in chamber geometry, specifically, an increase in the ratio of major to minor semiaxis. This study, then, offers an estimate of the error introduced by employing the Sandier and Dodge or similar thin-walled ellipsoidal models for computation of mean circumferential stress.

To determine whether subsequent improvement in left ventricular ejection fraction can be predicted from preintervention coronary arteriograms, we divided 63 patients with acute myocardial infarction into two groups based on findings at emergency coronary arteriography at a mean of 7 hr after onset of symptoms: (1) a "no-flow" group with an occluded infarct-related artery and no easily visible collaterals (n = 36) and (2) a "limited-flow" group with either subtotal stenosis or total occlusion of the infarct-related vessel with intact collaterals (n = 27). Of the 63 patients, 61 underwent emergency procedures to establish reperfusion. At follow-up angiography (contrast or radionuclide) performed 12 + 7 days after infarction, global ejection fraction had increased significantly in patients with limited flow to the infarct zone and "successful" early reperfusion intervention due primarily to a significant increase in the regional ejection fraction in the infarct zone. Global ejection fraction fell significantly between baseline and follow-up in patients with no flow to the infarct zone and "unsuccessful" early reperfusion intervention due primarily to a fall in the regional ejection fraction of the noninfarct zone. Global and regional ejection fractions did not change significantly in patients with no flow to the infarct zone and successful early reperfusion or in patients with limited flow to the infarct zone and unsuccessful early reperfusion intervention. The elapsed time before reperfusion did not relate significantly to the change in either regional or global ejection fraction. However, the magnitude of improvement in both global and regional ejection fraction at follow-up was greater among patients with anterior infarcts than among those with inferior infarcts, possibly because baseline ejection fraction was lower in patients with anterior infarcts. These data indicate that among patients with acute myocardial infarction undergoing emergency coronary arteriography at a mean of 7 hr after onset of symptoms, improvement in global ejection fraction is unlikely to occur even after a successful early reperfusion intervention in the absence of preserved flow to the infarct area. However, among patients with subtotally occluded infarct-related arteries or significant collateral blood flow to the infarct zone. subsequent improvement in global and regional ejection fraction in the zone of myocardial infarction frequently occurs. Improvement in both global and regional ejection fraction may be more readily demonstrated in patients initially having more severe depression of these parameters.

Left ventricular (LV) function and hypertrophy, assessed during cardiac catheterization by quantitative biplane angiocardiography, were related to postcatheterization course in 36 patients found to have cardiomyopathy with depressed ejection fraction (EF). EF ranged from 0.09 to 0.41, LV mass (M) from 99 to 317 g/m 2 , LV end-diastolic volume (V) from 104 to 347 ml/m 2 , and ratio of M/V from 0.66 to 1.63. In this study, EF was used as an index of LV function; M/V ratio was considered to represent a relative degree of LV hypertrophy. Postcatheterization survival rates (PCSR) for all patients at 12, 24, and 36 months were 68.8 ± 7.8%, 49.9 ± 9.2%, and 32.8 ± 10.2%. The 36-month PCSR was significantly higher for patients (N = 15) with EF ≥ 0.20 (75.1 ± 14.5%) than for those (N = 21) with EF < 0.20 (0%) ( P < 0.01). The 36-month PCSR was also significantly higher for patients (N = 19) with M/V ratio ≥ 0.90 (53.6 ± 14.8%) than for those (N = 17) with M/V ratio < 0.90 (12.4 ± 10.4%) ( P < 0.05). M/V ratio appeared to influence survival at least in part independently of EF. For patients with EF ≥0.20 M/V ratio ≥ 0.90 was associated with a higher 36-month PCSR (100%) than was M/V ratio < 0.90 (25.0 ± 6.5%). Likewise, for patients with EF < 0.20, M/V ratio ≥ 0.90 was associated with a higher 24-month PCSR (65.1 ± 16.8%) than was M/V ratio < 0.90 (6.8 ± 9.1%); but at 36 months, PCSR was < 10% for both subgroups. Patients (N = 16) with mitral regurgitation (MR) > 0.70 liters/min/m 2 had a mean value for V (212.9 ± 74.1 ml/m 2 ) significantly larger than for those (N = 20) without MR or with MR < 0.70 liters/min/m 2 (168.8 ± 40.7 ml/m 2 ) ( P = 0.0278). Although this suggests that dilatation of the mitral valve annulus contributed to the development of the regurgitation, the large overlap in V values implies that additional mechanisms played a role. This study describes quantitatively a spectrum of hemodynamic abnormalities in patients who had cardiomyopathy with depressed EF, and demonstrates that the present series of patients had a high postcatheterization mortality rate. Both EF and M/V ratio were of prognostic value and thus appear to be useful indices for classifying such patients.

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