Correlation of angiographic estimates of myocardial infarct size and accumulated release of creatine kinase MB isoenzyme in man

Accumulated creatine kinase MB isoenzyme release (sigma CK-MB) during acute myocardial infarction was correlated with biplane left ventricular (LV) angiographic estimates of percent abnormally contracting segment (%ACS) and ejection fraction (EF) in 35 patients who underwent diagnostic angiography at a mean of 33 +/- 4 days post myocardial infarction (MI). Of the 35 patients, 18 had no evidence of prior MI and their sigma CK-MB showed good correlation with %ACS (r = 0.84) and with EF (r = - 0.78). An additional two patients with first (inferior) infarct secondary to stenosis of the right coronary artery proximal to the origin of the right ventricular arterial blood supply had disproportionately large sigma CK-MB, suggesting a combination of LV and RV necrosis. In the 15 patients with prior infarct, there was no significant correlation between sigma CK-MB and %ACS or EF. However, in the subgroup of patients with anterior MI, %ACS correlated with sigma CK-MB, both in patients with no prior MI (r = 0.88, N = 12) and in patients with prior MI (r = 0.69, N = 9). These independent angiographic and enzymatic data suggest that enzymatic infarct size estimates utilizing accumulated CK-MB release may be a valid and reliable clinical measure for assessing the extent of LV necrosis in the setting of acute anterior myocardial infarction. However, limitations may exists in certain cases of inferior MI, probably because of concomitant right and left ventricle necrosis.

Quantitative assessment of ventricular performance in unstable ischemic heart disease by dextran function curves

The ability to quantitate the amount of permanent left ventricular dysfunction in patients with unstable ischemic heart disease would have important clinical value. Left ventricular function curves were constructed in sixteen patients with acute myocardial infarctions and five patients with unstable angina pectoris syndrome at an average of 56 hours (+/- 8) after the onset of symptoms. Fifty ml increments of low molecular weight dextran were rapidly infused into the right antrium during constant monitoring of the pulmonary artery end-diastolic pressure (PAEDP) via a Swan-Ganz thermodilution catheter. An average of 400 ml (range 200-800) was infused to produce a significant change in the PAEDP (range 3-13 mm Hg). The cardiac index was measured before and after the dextran infusion. The slope of the left ventricular function curve was calculated by dividing the change in the cardiac index by the change in the PAEDP. The sixteen patients with acute myocardial infarction underwent left heart catheterization and left ventricular biplane angiography an average of six months later. The five patients with unstable angina pectoris were studied within one month. The slope value of the left ventricular function curve was compared angiographic ejection fraction by linear regression analysis and the correlation coefficient was 0.80. These data demonstrate 1) the slope of the left ventricular function curve in patients with acute myocardial infarction or unstable angina correlates well with the angiographically calculated ejection fraction; 2) as early as two days post myocardial infarction, the residual impairment of left ventricular function can be estimated.

Modern approach to the patient with acute myocardial infarction

This presentation has described the modern approach to the patient presenting with chest pain suspected as acute myocardial infarction. Noninvasive and invasive methods have been applied to estimate the extent of the myocardial damage and to monitor the electrical, hemodynamic and metabolic changes during the acute phase. In addition to the use of standard analgesics and antiarrhythmics, measurement of the determinants of left ventricular function by noninvasive and invasive techniques provides a physiologic basis for administration of available pharmacologic agents that can alter the afterload, contractile state, preload, heart rate, metabolic state and infarct size. Information from the Swan-Ganz catheter can describe hemodynamic categories that can be optimally managed by regulation of the left ventricular filling pressure. Patients managed in this manner can be identified for early hospital discharge at 7-10 days. Other patients less than 50 years of age or those experiencing recurrent arrhythmias, ischemic pain or evidence of left ventricular dysfunction may be candidates for coronary arteriography and left ventricular angiography before hospital discharge.

Treatment of congestive heart failure

In treating heart failure, the physician must remain cognizant of pathophysiology as he prescribes and monitors therapy. In addition to seeking underlying and precipitating causes of the patient's heart failure, he must treat the congestive state by enhancing myocardial contractility, controlling excessive fluid retention, and reducing afterload. Figure 7 summarizes the theoretical shifts on a patient's left ventricular function curves that might occur with therapy. Left ventricular function might move from point A to point B with diuretic therapy, but overdiuresis could aggravate symptoms of low cardiac output, including postural hypotension. Digitalis would effect a shift from A to C. Isosorbide dinitrate would produce a shift from A to D in a patient not on digitalis and from C to D in a patient already receiving digitalis. Isosorbide dinitrate, in conjunction with more usual therapeutic measures, has proved clinically beneficial in the treatment of heart failure.

Gallbladder disease in patients 20 years of age and under

Cholecystitis is uncommon in individuals under 21 years of age and, when present, usually is associated with pregnancy, sepsis, metabolic defects, hemolytic anemia, or hereditary disorders. Over the past 4 1/2 years, 92 patients 20 years of age and younger have been admitted to our institution with gallbadder disease. Of these patients, 88 were female and 76 were of Mexican-American origin. Only two of these individuals had associated hemolytic anemia. Seventy-six of these females had been pregnant at least once, and 57 were more than 10 pound overweight. Cholecystectomy was done on 88 of these patients, and cholelithiasis was found in 86. There were 28 explorations of the common bile duct, 18 of which were positive. This series represents an earlier onset of cholelithiasis in this population.

Reduction of hospital mortality rate of acute myocardial infarction with glucose-insulin-potassium infusion

Free fatty acids (FFA), the predominant myocardial energy substrate, are present in increased quantities immediately following acute myocardial infarction (AMI) and may cause deleterious alterations in cardiac rhythm, oxygen consumption, and mechanical performance. In an attempt to suppress FFA and simultaneously increase the availability of carbohydrate as a myocardial substrate, 70 patients with unequivocal AMI were administered a right atrial infusion of glucose-insulin-potassium (GIK) (300 gm. of glucose, 50 U. of regular insulin, and 80 mEq. of KC1 per liter of H2O) at a constant rate of 0.5 to 2.0 ml. per kilogram per hour for 48 hours. A dramatic fall in FFA (944 +/- 57 to 289 +/- 16 muEq per liter, p less than 0.0005) occurred during GIK infusion, and FFA rebounded to 420 +/- 39 muEq per liter (p less than 0.005) when GIK was discontinued. The hospital mortality rate in the 70 GIK recipients was compared to that of 64 untreated patients (controls) from the same coronary-care unit during the previous year. GIK and control groups had similar severity of infarction as assessed by prognostic scales of Killip, Peel, and Norris, respectively. The hospital mortality rate was reduced in the GIK recipients compared to the control group (11/70 vs. 19/64, p less than 0.05). In patients without history of prior myocardial infarction, the mortality rate was reduced four-fold in GIK recipients compared to controls (6 vs. 24 per cent, p less than 0.05). Complications of GIK infusion were infrequent and included chiefly hyperglycemia and hyperkalemia, both of which dictated meticulous monitoring of serum chemistries. The data suggest that suppression of plasma FFA with GIK infusion may be associated with a significant reduction in the hospital mortality rate of acute myocardial infarction.

Glucose-insulin-potassium, free fatty acids and acute myocardial infarction in man

In patients with stable coronary artery disease, a GIK solution may increase arterial glucose and the arterial-coronary sinus difference of glucose across the myocardium. In the same patients, GIK may reduce arterial free fatty acids as well as the arterial-coronary sinus difference of free fatty acids across the myocardium. As the arterial values of free fatty acids fall, so does the arterial-coronary sinus difference of free fatty acid across the myocardium, defining a myocardial threshold for free fatty acids of approximately 200 mEq/L. Glucose-insulin-potassium may lower free fatty acid values to near or below myocardial threshold in patients with acute myocardial infarction despite recurrent pain. Preliminary data suggest that GIK in the concentration and infusion rates used in this study may favorably influence survival in patients with acute myocardial infarction.

Effects of glucose-insulin-potassium on myocardial substrate availability and utilization in stable coronary artery disease. Studies on myocardial carbohydrate, lipid and oxygen arterial-coronary sinus differences in patients with coronary artery disease

To assess the metabolic effects of myocardial substrate alteration in patients with coronary artery disease, glucose-insulin-potassium solution was administered intravenously for 30 minutes to 14 men with stable angiographically documented coronary artery disease. The glucose-insulin-potassium solution (300 g of glucose, 50 units of regular insulin and 80 mEq of potassium chloride per liter of water) was infused at a constant rate in each patient, but individual infusion rates ranged from 0.013 to 0.032 ml/kg per min (4 to 10 mg glucose/kg per min) in the 14 patients. Simultaneous arterial and coronary sinus samples were obtained at 15 minute intervals during a stable 30 minute control period and again at 15 minute intervals during the infusion; samples were assayed for glucose, lactate, free fatty acid and oxygen content. In all 14 patients, during the glucose-insulin-potassium infusion, arterial glucose and lactate increased and arterial free fatty acid levels fell; the magnitude of the changes in arterial lactate and free fatty acids was related to the rate of infusion. Arterial-coronary sinus differences (A-Cs) for glucose, lactate and free fatty acid levels correlated with the arterial concentrations of these substrates (r = 0.66, 0.87 and 0.79, respectively). Regression analyses demonstrated myocardial thresholds for the uptake of these substrates as follows: glucose 79 mg/100 ml; lactate 300 mu mole/liter; and free fatty acids 100 to 200 mu Eq/liter. Finally and most importantly, the reduction in A-Cs oxygen values after glucose-insulin-potassium infusion correlated with the reduction in A-Cs free fatty acid levels (r = 0.64, P less than 0.0001). This observation suggests that, in patients with coronary artery disease, glucose-insulin-potassium infusion may significantly diminish myocardial oxygen requirements by reduction of myocardial free fatty acid utilization and simultaneous enhancement of myocardial carbohydrate utilization. Myocardial substrate availability may be an important determinant of myocardial oxygen demand in patients with coronary artery disease. Infusion of glucose-insulin-potassium solution has the potential to alter myocardial substrate availability, thus improving the balance between myocardial oxygen demand and supply.

Comparison of indices of muscle and pump performance in patients with coronary artery disease

During diagnostic cardiac catheterization of 20 patients, 19 of whom had coronary artery disease (CAD), left ventricular (LV) performance was assessed by both muscle function indices and pump function indices. Muscle function indices included max dP/dt, Vpm, Vce5, and Vmax, the latter derived from both total pressure (TP) and developed pressure (DP) using catheter-tip manometry. Pump function indices included LV ejection fraction (EF) and percent abnormally contracting segment (ACS), determined from biplane LV angiography. Muscle and pump function indices were also compared to the presence of the S3 (ventricular diastolic) gallop. Correlations existed between EF and Vmax (TP), EF and Vpm, percent-ACS and Vmax(TP), and percent-ACS and Vpm, with r values of 0.760, 0.777, -0.884, and -0.841, respectively. Vmax(TP) and Vpm also correlated quantitatively with the presence of the S3 gallop (p less than 0.0005). Total pressure-derived muscle function indices appear to adquately describe mean LV performance in patients with CAD and ACS, but these muscle function indices are probably highly dependent upon the size of the myocardial scar.

A clinical experience with intraoperative autotransfusion

Utilizing a disposable unit, intraoperative autotranfusion was employed during surgery in 53 patients admitted to the Bexar County Teaching Hospital at the University of Texas Health Science Center at San Antonio. During the two-year period of study, 26 patients underwent surgery for major traumatic injuries, 8 for ruptured ectopic pregnancy and 19 for miscellaneous emergency or elective conditions. The indication for intraoperative autotransfusion was an anticipated blood loss of 1,000 ml or more. Contraindications for its use were colon injury or localized infection. Over 325 units of blood were salvaged and returned directly to these patients during surgery. One death related to the use of the autotransfusor unit was due to massive air embolism. Twenty other deaths were associated with severe injuries and irreversible shock requiring greater than 3,600 ml of both autologous and homologous blood. Eight of these patients demonstrated severe pancoagulopathies. In the remaining patients, clotting factors and plasma or urine hemoglobin levels were transiently abnormal. However, there were no clinically apparent bleeding defects or renal problems detected. Postoperative blood cultures were consistently negative. It is concluded that intraoperative autotransfusion, when properly employed, is a safe, practical and technically feasible procedure.