Charles E. Rackley

Measurement of Left Ventricular Wall Thickness and Mass by Echocardiography

Echocardiographic measurements of minor axis and wall thickness and calculations from these two measurements of left ventricular end-diastolic volume and mass were performed in 24 patients and compared with angiocardiographic measurements of the same variables in corresponding patients. The echo-measured left ventricular end-diastolic chamber dimension (Dd) correlated closely with the angiographic minor axis in the AP plane (correlation coefficient 0.87 and SE ± 0.45 cm) and with the minor axis from the lateral film (r = 0.91, SE ±0.39 cm). Similar correlations were found between measurements by these methods of wall thickness (r = 0.89, SE ±1.3 mm), of end-diastolic volume (r = 0.94, SE ±30.6 cc), and of left ventricular mass (r = 0.88, SE ±49.19 g). The reproducibility of this method was established by independent recordings and measurements of echo Polaroid films by two observers. The percent systolic wall thickening, as determined by echocardiography, identified subjects with ejection fractions greater or less than 0.50. Echocardiography offers a reliable and reproducible method for measuring left ventricular wall thickness and mass. Finally, ultrasound may provide an accurate method for measuring systolic wall thickening in man.

Unstable angina pectoris: National cooperative study group to compare surgical and medical therapy: II. In-Hospital experience and initial follow-up results in patients with one, two and three vessel disease

Abstract A prospective randomized study comparing intensive medical therapy with urgent coronary bypass surgery for the acute management of patients with unstable angina pectoris was carried out by nine cooperating medical centers under the auspices of the National Heart, Lung, and Blood Institute. Between 1972 and 1976, a total of 288 patients were entered into the study. All patients had transient S-T or T wave changes, or both, in the electrocardiogram during pain; 90 percent had pain at rest in the hospital, and 76 percent had multivessel coronary disease. The medically and surgically treated patients were comparable with respect to clinical, electrocardiographic and angiographic characteristics and left ventricular function. During the total study period, the hospital mortality rate was 5 percent in the surgical group and 3 percent in the medical group (difference not significant). The rate of in-hospital myocardial infarction was 17 and 8 percent in the respective groups (P In the 1st year after hospital discharge class III or IV angina (New York Heart Association criteria) was more common in medically than in surgically treated patients with one vessel disease (22 percent versus 3 percent, P The results indicate that patients with unstable angina pectoris can be managed acutely with intensive medical therapy, including the administration of propranolol and long-acting nitrates in pharmacologic doses, with adequate control of pain in most patients and no increase in early mortality or myocardial infarction rates. Later, elective surgery can be performed with a low risk and good clinical results if the patients angina fails to respond to intensive medical therapy.

Regional Left Ventricular Performance in the Year following Myocardial Infarction

The relationship of abnormal regional myocardial performance to left ventricular (LV) function 2-12 months following transmural myocardial infarction was investigated in 25 patients by quantitative biplane angiocardiography. Abnormally contracting segments (ACS) (akinetic or dyskinetic) of the LV were identified in 24 patients. Their sites correlated with the electrocardiographic locations of infarction. ACS were expressed as a percentage (ACS%) of the end-diastolic ventricular circumference, and the percentages obtained correlated with ejection fraction (EF) (r = —0.838, P = 0.0001) using a quadratic regression equation. The group of patients (N = 8) with heart failure (paroxysmal nocturnal dyspnea and/or ventricular gallop sound) demonstrated a significantly lower mean value for EF (P = 0.0003) and a significantly larger mean value for ACS% (P = 0.0041) than the group of patients (N = 16) without heart failure. EF sharply separated the two groups. ACS% was a poor separator because in the majority of patients in both groups it was between 14 and 38%. Since EF sharply separated the heart failure and non-heart failure groups but ACS% did not, a theoretic model was developed to assess the contribution of the remaining myocardium to LV function. The curve described by the model did not differ significantly from the curve derived from the quadratic regression equation. Data from heart failure and non-heart failure patients were generally separated by a point (EF = 0.30, ACS = 23%) on the theoretic curve. Abnormal function of the nonakinetic myocardium was considered to be present when observed EF was lower than predicted EF for the observed ACS%.Thus, within the year following transmural myocardial infarction, the relative size of an abnormally contracting region of the ventricle was quantitatively related to impairment of LV function. The spherical model not only provided a framework for relating the clinical status of a patient to both ventricular function and size of the ACS, but also offered a means of estimating the function of the myocardium that appeared angiographically to be nonakinetic.

Coronary anatomy and arteriography in patients with unstable angina pectoris

Abstract A prospective series of 188 patients with the syndrome of unstable angina pectoris undergoing coronary arteriography was reviewed to determine the spectrum of anatomic coronary artery disease, suitability for coronary revascularization and in-hospital morbidity and mortality. Thirty-two patients demonstrated normal to moderately diseased coronary arteries. None of these patients sustained myocardial infarction or died. Twenty patients (10.6 percent) had normal coronary arteriograms. Of the 156 patients having severe coronary artery disease (greater than 70 percent stenosis), 20 patients (13 percent) had left main coronary artery disease. One hundred forty-two patients (91 percent) were potential candidates for coronary surgery; 14 were not candidates because of distal vessel disease or poor left ventricular function. During cardiac angiography or in the subsequent hospital period 12 patients sustained a myocardial infarction and 7 of these died. Of these seven, six had left main coronary artery disease and one had three vessel disease. In three patients who died (1.9 percent of those with severe coronary artery disease) the death may have been related to cardiac catheterization because evidence of myocardial necrosis began within 24 hours of study. Thus, patients with the syndrome of unstable angina pectoris usually presented with severe coronary artery disease and were candidates for coronary revascularization. The anatomic severity of coronary artery disease appeared to be the most important factor contributing to myocardlal infarction or death after cardiac catheterization. Mortality after catheterization was primarily associated with left main coronary artery disease.

Left Ventricular Function and Hypertrophy in Cardiomyopathy with Depressed Ejection Fraction

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/m2, LV end-diastolic volume (V) from 104 to 347 ml/m2, 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/m2 had a mean value for V (212.9 ± 74.1 ml/m2) significantly larger than for those (N = 20) without MR or with MR < 0.70 liters/min/m2 (168.8 ± 40.7 ml/m2) (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.

Quantitative coronary arteriography. Coronary anatomy of patients with unstable angina pectoris reexamined 1 year after optimal medical therapy.

The effect of optimal medical therapy on coronary arterial anatomy was evaluated in 25 patients with unstable angina pectoris. Coronary arterial diameter and the extent of stenosis were exactly quantified in two successive coronary angiograms performed in each patient at approximately a 1 year interval (range 4 to 31 months, average 12.4 months). The measuring device was a vernier caliper with an accuracy of 0.05 mm. After 1 year of medical treatment 69 stenoses of the three major coronary branches showed no significant change: The average degree of area obstruction of 27 stenoses of the right coronary artery was 79 and 64 percent in the initial and second studies, respectively; that of 26 stenoses of the left anterior descending artery 76 and 77 percent, respectively, and that of 16 stenoses of the left circumflex artery 73 and 83 percent, respectively. In 11 patients, 14 stenoses showed a distinct progression of more than 20 percent area obstruction. All six stenoses showing more than 90 percent obstruction in the first angiogram progressed to complete obstruction within 1 year. In five other patients area obstruction in five stenoses regressed by more than 20 percent. The anatomy of vessel segments distal to obstructions remained unchanged within 1 year. It is concluded from these quantitative measurements that the distribution and severity of coronary lesions are similar in patients with stable and unstable angina pectoris. Coronary anatomy showed no significant change after 1 year of medical treatment. The rate of progression was substantially lower than previously reported in patients with stable angina pectoris.

Prospective Randomized Trial of Glucose-Insulin-Potassium In Acute Myocardial Infarction

Abstract Fifty consecutive patients admitted within 12 hours of the onset of symptoms of acute myocardial infarction were randomly assigned to treatment with intravenous glucose-insulin-potassium infusion (23 patients) or to a control group (0.5 N sodium chloride infusion) (27 patients). The glucose-insulin-potassium infusion consisted of 30 g glucose, 50 U regular insulin and 80 mEq KCl per liter infused at 1.5 ml/kg per hour for 2 days. Serial measurements were made of pulmonary arterial end-diastolic pressure, cardiac index, daily fluid intake and output, serum glucose, potassium, urea nitrogen, free fatty acids, osmolarity, creatine kinase-MB isoenzyme and cardiac rhythm. Although all patients admitted comatose died (three glucose-insulin-potassium recipients, one control subject), hospital mortality in patients admitted noncomatose was 0 percent (0 of 20) in glucose-insulin-potassium recipients versus 12 percent (3 of 26) in the control group (three deaths secondary to late pump failure). Glucose-insulin-potassium recipients experienced 4.9 ± 1.3 hours of three or more premature ventricular complexes/min compared with 11.1 ± 1.9 hours for control subjects ( P These data demonstrate that, in patients with acute infarction, glucose-insulin-potassium infusion (1) does not adversely alter hemodynamics, (2) reduces free fatty acids, (3) diminishes frequency of ventricular arrhythmias, but (4) has no demonstrable effect on infarct size as assessed with creatine kinase isoenzyme values. In this ongoing randomized clinical trial, the number of patients studied is too small to permit definite conclusions to be reached regarding the effect of glucose-insulin-potassium infusion on hospital survival.

Hemodynamic Evaluation of Left Ventricular Function in Shock Complicating Myocardial Infarction

Twenty-two patients with shock complicating myocardial infarction were studied hemodynamically and, despite pharmacologic therapy and regulation of intravascular volume, 16 (73%) subsequently expired. Pulmonary artery end-diastolic pressure (PAEDP) or left ventricular end-diastolic pressure (LVEDP) was > 15 mm Hg in 18 of the 22 patients, and cardiac index (CI) was ≤2.3 liters/min/m2 in 17 of 22 patients. Fourteen of the 18 patients with PAEDP or LVEDP > 15 mm Hg expired, while two of the four patients with a PAEDP or LVEDP < 15 mm Hg survived. Thirteen of 15 individuals with a CI < 2.3 liters/min/m2 died, and four of seven with a CI ≤ 2.3 liters/min/m2 survived. A ventricular gallop (S3) was audible in 15 patients with PAEDP or LVEDP varying from 13 to 60 mm Hg. In 11 patients with an S3 who expired, the PAEDP or LVEDP ranged from 22 to 60 mm Hg. Mean peripheral vascular resistance was 41.3 units in survivors and 67.8 units in nonsurvivors. Six of eight patients who did not survive the period of hospitalization had a depressed response to dextran infusion manifested by a greater increase in PAEDP or LVEDP than in CI.Hemodynamic evaluation permitted early identification of measurements associated with 100% mortality despite intensive medical treatment. These findings included: (1) PAEDP or LVEDP > 28 mm Hg and (2) PAEDP or LVEDP > 15 mm Hg in association with a CI < 2.3 liters/min/m2. Patients in cardiogenic shock with these hemodynamic alterations are presumably candidates for cardiocirculatory mechanical assisting devices and possibly for further surgical intervention.

Relation of graded exercise test findings after myocardial infarction to extent of coronary artery disease and left ventricular dysfunction

Abstract To evaluate the effectiveness of the graded exercise test in predicting the extent of coronary artery disease and the degree of left ventricular dysfunction in patients with prior myocardial infarction, 100 consecutive patients underwent both graded exercise testing and coronary and left ventricular angiography at a median of 4 months after infarction. The studies caused no complications. An equal number of patients had anterior and inferior infarction. Coronary artery disease, defined as 70 percent or greater stenosis of luminal diameter, was present in three vessels in 31 patients, in two vessels in 35 patients, in one vessel in 33 patients and in no vessel in one patient. With “diagnostic” electrocardiographic criteria of 1 mm or greater J point depression plus a flat or downsloping S-T segment, 31 patients had an electrocardiographically positive exercise test; 27 of these (87 percent) had two or three vessel coronary artery disease. Of the 21 patients with a negative exercise test, 62 percent had coronary artery disease in no more than one vessel, 33 percent in two vessels and 5 percent in three vessels. Fourteen patients had S-T segment elevation during exercise; these patients had a lower ejection fraction and larger angiographic scar size than the remaining 86 patients. Patients terminating exercise because of symptoms of left ventricular dysfunction (fatigue or dyspnea) showed correlation between duration of exercise and ejection fraction ( r = 0.65) and between duration of exercise and angiographic scar size ( r = −0.62). Thus, several months after infarction, the graded exercise test can be performed safely and can be utilized to predict the extent of coronary artery disease and left ventricular dysfunction in selected groups of patients.

Left Ventricular Hemodynamics in Anterior and Inferior Myocardial Infarction

Initial hemodynamics were studied in 50 patients with acute myocardial infarction classified according to anterior or inferior location. Twenty-two had anterior transmural infarction (indicated by Q wave changes), 12 had anterior necrosis (S-T and T wave changes plus increases in serum enzymes), 11 had inferior transmural infarction and 5 inferior necrosis. When initial left ventricular filling pressure, stroke index, heart rate and stroke work index were considered together in all patients, there was a significant difference (P