Return of left ventricular function after reperfusion in patients with myocardial infarction: importance of subtotal stenoses or intact collaterals.

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.

Prospective randomized trial of intravenous and intracoronary streptokinase in acute myocardial infarction.

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 1 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 less than .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.

The importance of angled right anterior oblique views in improving visualization of the coronary arteries. Part I: Caudocranial view.

Three hundred patients were examined to determine the value of the caudocranial right anterior oblique view (RAO) in revealing or improving visualization of lesions in the proximal and mid-left anterior descending artery (LAD), the origins of the septal and diagonal arteries, and the distal branches of the right coronary artery (RCA). The proximal and mid-LAD were shown to greater advantage in 80% of cases, the diagonal arteries in nearly 75%, the septal vessels in more than 90%, and the posterior descending and posterolateral branches of the distal RCA in more than 80%; in addition, the cranial RAO view revealed previously unsuspected lesions in 7% of the proximal and mid-LAD arteries and 26% of the septal vessels. In addition to superior visualization, this view gives satisfactory exposure even in extremely large patients and may also be helpful in coronary angioplasty.

The importance of angled right anterior oblique views in improving visualization of the coronary arteries. Part II: Craniocaudal view.

The craniocaudal right anterior oblique view (RAO) of the left coronary artery was employed for 100 angiograms. Visualization of the proximal and left distal circumflex, first and second marginal, and proximal left anterior descending artery (LAD) and its branches was compared with that on the non-angled RAO projection. Diagnostic accuracy was increased with the caudal RAO view in 88% of proximal circumflex segments, 69% of distal circumflex segments, 52% of first marginal segments, 33% of second marginal segments, and 33% of proximal LAD systems. Of 68 lesions identified, 15 (22%) were seen only on the caudal RAO view. The authors feel that this projection is a valuable and necessary addition to routine views of the left coronary artery, and that optimum evaluation is achieved by routine use of a combination of caudal, non-angled, and cranial RAO views.

Advantages of the caudocranial left anterior oblique left ventriculogram in adult heart disease.

Biplane axial left cineventriculography represents the most accurate diagnostic technique for evaluating acquired and congenital heart disease. However, data have accumulated to indicate that without angled views of the left ventricle, the diagnosis will be incomplete and inaccurate in a significant number of patients. Left ventriculography is the acknowledged standard for left ventricular performance. However, comparison of the conventional or nonangled left anterior oblique left ventriculogram with the angled views of the left ventricle obtained with either two dimensional ultrasound or radionuclide left ventriculography may in many cases be invalid because dissimilar views are compared. The cranial-left anterior oblique view allows more accurate assessment of the precise degree and extent of asynergy, left ventricular aneurysms and ventricular septal defects. Left ventricular outflow tract abnormalities such as discrete subaortic stenosis and the obstructive form of hypertrophic cardiomyopathy can easily be distinguished. Lesions involving the mitral valve, especially mitral valve prolapse, are readily evaluated. Lastly, comparison with noninvasive tests of left ventricular performance can be more accurately performed.

Measurement of effective renal plasma flow in congestive heart failure.

In the management of patients with congestive heart failure (CHF), it is often desirable to have precise knowledge of overall renal function, including the effective renal plasma flow (ERPF). It has long been recognized that ERPF is diminished in CHF. Since glomerular filtration rate is often decreased to a much lesser extent, other noninvasive procedures such as the measurement of creatinine clearances may not be entirely suitable. ERPF determination by the single plasma sampling (SPS) method affords a rapid, simple, noninvasive, and economical technique that is quite accurate and reproducible. A SPS method has been well-tested in patients following renal transplantation plus a wide variety of nephrological disorders. We have been concerned whether the SPS method would be valid in volume expanded patients. In 28 determinations of ERPF in patients with CHF, and in five patients who did not have CHF, we have found the SPS estimation of ERPF to yield results that are not clinically significantly different from those obtained by the detailed compartmental analysis method. The volumes of 131I-orthoiodohippurate (OIH) distribution were found to be somewhat higher in CHF than in controls, but fractional rate constants were proportionately lower so that intercompartmental flow rates and OIH concentrations were not different from controls. Therefore, the SPS estimation of ERPF is valid in patients with CHF and may be useful in monitoring the renal effects of various hemodynamic and pharmacological interventions.

Advantage of the cranial-right anterior oblique view in diagnosing mid left anterior descending and distal right coronary artery disease.

The value of the cranial-right anterior oblique view in uncovering or improving the arteriographic visualization of lesions in the mid left anterior descending coronary artery, the origin of its diagonal and septal branches and the distal branches of the right coronary artery was analyzed in 300 consecutive patients. The cranial-right anterior oblique view was compared with standard and other angled views. In the mid left anterior descending artery the view provided improved visualization over the other views in 80 percent of cases and uncovered lesions in 7 percent. In the septal arteries, the view improved visualization in more than 90 percent of cases and uncovered lesions in 26 percent. In the diagonal branches, the view improved visualization in nearly 75 percent of cases. In the distal right coronary artery there was improved visualization of the posterior descending and posterolateral branch arteries in more than 80 percent of cases. The cranial-right anterior oblique view was also the most advantageous view from a technical standpoint, yielding satisfactory exposure factors in obese and extremely heavy patients.

Glucose-insulin-potassium induced alterations in individual plasma free fatty acids in patients with acute myocardial infarction.

Total and individual plasma free fatty acids (FFA) were measured on admission and over the next 4 days in 24 patients admitted to the hospital with chest pain and suspected acute myocardial infarction (AMI). In a prospective randomized fashion, the patients were either given an infusion of 300 gm of glucose, 50 units of insulin, and 80 mEq of KCl per liter at a rate of 1.5 ml/kg/hr over the initial 48 hours of hospitalization, or they served as controls receiving conventional therapy. Eleven patients were in the control group and 13 were in the glucose-insulin-potassium (G-I-K) group. Twenty-one of the patients had an AMI by CK-MB rise and ECG changes (in the G-I-K group three did not evolve AMI). The total plasma FFA were 840 +/- 134 microM/L in the controls and 933 +/- 160 microM/L in the G-I-K group initially (prestudy). Total FFA rapidly fell in the G-I-K group and then rebounded when G-I-K was stopped. In contrast, total FFA values fell gradually in the control group over the 4-day period. The individual FFA had similar percentages initially in the two groups. In the control group the percent of individual plasma FFA was unchanged over the period studied, although there was some mild random day-to-day fluctuation. In contrast in the G-I-K group linoleic acid fell both during and after the infusion was stopped (26.8% to 19.1% P less than 0.001). Arachidonic acid doubled in percentage of the total FFA value during G-I-K infusion (3.1% to 6.5%, P less than 0.002) and returned to the control value when it was stopped. Thus G-I-K infusion during AMI reduces the total level of plasma FFA while increasing the percent of arachidonic and decreasing the percent of linoleic acid, observations proposed to reflect improved membrane stability of the ischemic myocardium.

Limited exercise testing soon after myocardial infarction. Correlation with early coronary and left ventricular angiography.

Forty-eight patients within 3 weeks of myocardial infarction underwent both limited treadmill graded exercise testing and coronary and left ventricular angiography. Nineteen (90%) of 21 patients with positive exercise tests (greater than or equal to 1 mm ST depression, angina, or both) had multivessel coronary artery disease. In the 27 patients with negative exercise test results, 15 (55%) had multivessel disease, 11 (41%) had single-vessel disease, and one (4%) had no coronary stenosis. Exercise-induced ST segment elevation occurred in 24 patients and predicted a significantly lower ejection fraction and higher angiographic abnormally contracting segment size. Patients experiencing angina during or after exercise had a significantly shorter 2-year survival (54% +/- 21%) than patients without exercise-induced angina (97% +/- 3%) (p less than 0.03). Thus limited exercise testing postinfarction is useful in evaluating the presence of multivessel coronary artery disease and left ventricular dysfunction and predicting long-term survival.

Significance of the caudal left-anterior-oblique view in analyzing the left main coronary artery and its major branches.

The authors describe the value of the caudal left-anterior-oblique view in visualizing the following arteries: left main coronary, proximal circumflex, early-arising first marginal, proximal left anterior descending, first diagonal, and anomalous septal perforators from the circumflex system. The technique involves movement of the parallelogram (x-ray tube--image intensifier combination) to the left 55-65 degrees and caudal angulation of 15-20 degrees. To promote additional profiling of the left coronary system, imaging is performed after full expiration. In our series of 100 patients, this view is indispensable in determining significant pathology in the arteries of the proximal left coronary system.