Variability in the analysis of coronary arteriograms

Variability in coronary arteriogram readings was studied by having cine films from ten patients read by eleven readers. Three of the eleven subsequently met as an expert panel to provide a joint evaluation which could serve as a standard. Considerable variability was found between individual readers and between readers and the panel. The average standard deviation for estimation of any segmental stenosis by any single reader was 18%. Disagreement about the number of major vessels with a 70% stenosis occurred 31% of the time. Discrepancies were most likely to occur in analyzing distal arterial segments, in reading nonopacified segments, and during analysis of films showing more severe disease or having poorer technical quality. Recent experience in reading arteriograms seemed to be the most important characteristic in determining the accuracy of a reader. A protocol for the use of three readers is suggested.

Correlation of polarcardiographic criteria for myocardial infarction with arteriographic and ventriculographic findings (substantiation of transmural and presentation of non-transmural criteria)

Sensitivity and specificity of polarcardiographic criteria for myocardial infarction were compared with those of electrocardiographic criteria in 108 patients with chest pain syndromes who were referred for coronary arteriography and left ventriculography. With the combination of total occlusion of at least one coronary artery and abnormal systolic contraction of at least part of the left ventricle as the best available documentation of myocardial disease, sensitivity and specificity were 70% and 67%, respectively, using electrocardiographic criteria and 80% and 73% using polarcardiographic criteria, for both anterior and inferior myocardial infarction. Another polarcardiographic criterion--rightward shift in R latitude at 10 msec after onset of QRS--occurred concurrently with vessel occulusion in 16 of 17 patients (94%), in four of whom this was the only objective evidence of myocardial infarction, and three of whom there was no manifest abnormality of wall contraction. This criterion is considered evidence of non-transmural myocardial infarction, probably in the subendocardial layer near the apex of the left ventricle. When such evidence is added, sensitivity of polarcardiographic criteria increased to 84%, and specificity decreased to equal that of the electrocardiographic criteria (67%).

Myocardial perfusion imaging with 99m-Tc or 113m-In macroaggregated albumin: correlation of the perfusion image with clinical, angiographic, surgical, and histologic findings

Scintillation camera myocardial perfusion images were performed in 77 patients with proved or suspected ischemic heart disease following the intracoronary injection of 1.5 mCi 99m-Tc or 113m-In macroaggregated albumin. Perfusion images were classified as normal (36) or abnormal (41), and the location of abnormality was noted. Thirty-seven out of 41 patients with abnormal images had prior myocardial infarction based on history (30), ECG Q-waves (27), local contraction pattern abnormality (23), or direct surgical (9) or histologic (4) inspection, either singly or in combination. Three out of five patients with pre-infarction angina had image defects-none had evidence of infarction by ECG, ventriculogram, or surgical inspection. Coronary artery stenosis correlated with image defects to the extent that myocardial infarction was associated; 28 out of 29 patients with total occlusions and other evidence of infarction had image defects, four patients with complete occlusions but without other evidence of infarction had normal images. We conclude that, excepting patients with pre-infarction angina, this technique is more sensitive and direct in the identification of myocardial scar than standard ECG, clinical evaluation, or biplane left ventriculography.

Left ventricular function and coronary artery anatomy before and after myocardial infarction; a study of six cases

Six patients underwent cardiac catheterization before and after occurrence of a myocardial infarction. Results from the two procedures allowed the quantitation of changes in coronary artery anatomy and left ventricular performance associated with myocardial infarction.

Left ventricular biplane or single plane angiography and selective coronary angiography were used to evaluate coronary artery anatomy, left ventricular end diastolic pressure (LVEDP), left ventricular end diastolic volume (LVEDV), end systolic volume (LVESV), and systolic ejection fraction (SEF) under resting conditions.

Four patients had developed occlusion of the artery supplying the area of infarction. In five cases new or progressive contraction abnormalities occurred. One patient had no change in contraction pattern or SEF. Systolic ejection fraction fell in three patients, with no change in LVEDV. In two patients LVEDV rose and SEF fell.

These data demonstrate that a wide spectrum of functional abnormalities is associated with myocardial infarction. Infarction was always associated with significant coronary artery stenosis, but not necessarily associated with occlusion. The SEF and contractile pattern were the indicators of left ventricular dysfunction which most frequently deteriorated.

Changes in maximal exercise performance in the evaluation of saphenous vein bypass surgery

To evaluate the improvement in myocardial oxygen delivery following saphenous vein graft surgery (SVG) for angina pectoris (AP), 46 patients underwent a multistage treadmill test of maximal exercise capacity before and 3-22 (average 8) months after SVG. Variables from exercise testing were correlated with symptomatic response, left ventricular hemodynamics, and graft patency.

Functional capacity (NYHA) improved in 38 (85%), while 27 (59%) had a significant improvement in exercise performance. Functional aerobic impairment (FAI), or the percentage deviation from expected V O O2 max , improved by a mean of 16% ( P < 0.001). Maximal systolic pressure-rate product/100 increased 36 ( P < 0.002). Twenty of 29 (66%) with presurgical S-T segment depression had a normal response after surgery.

Thirty-three patients were studied for graft patency and had quantitative angiography. Seventeen had all grafts patent and demonstrated a mean improvement of 21% in FAI ( P < 0.0007). Those with occluded grafts showed no improvement in exercise performance. Sixteen of 22 (73%) with severe exercise impairment showed significant improvement, but only four of 14 (29%) with mild impairment showed a significant improvement. There were no mean changes in left ventricular end-diastolic pressure, cardiac index, contraction plot, or systolic ejection fraction (SEF) in any of the patients. Preoperatively nine had a depressed SEF (<50%), and no improvement in exercise performance could be demonstrated.

Maximal treadmill testing has demonstrated objectively that SVG can improve functional capacity and that it is correlated with graft patency. Ideal surgical candidates appear to be those with severe exercise impairment and unimpaired ventricular performance.

Quantitative angiocardioraphy in ischemic heart disease. The spectrum of abnormal left ventricular function and the role of abnormally contracting segments

Appropriate surgical and medical management of the patient with ischemic heart disease depends upon a thorough assessment of the clinical and pathophysiologic derangements in left ventricular function. This study examined the spectrum of abnormalities in ventricular function found in 66 patients with documented coronary artery lesions.

Catheterization and biplane angiocardiography were used to measure end-diastolic and end-systolic volume (EDV, ESV), systolic ejection fraction (SEF), ventricular mass (LVM), end-diastolic pressure (LVEDP), peak systolic and end-diastolic stress (PSS, EDS), and stroke work (SW). The pattern of ventricular contraction was assessed for hypokinesis, akinesis, and dyskinesis and graded according to severity.

The SEF, SW, and contractile pattern were sensitive and interrelated indicators of left ventricular contractile dysfunction or fiber shortening. Measurements of ventricular filling or fiber lengthening (EDV, LVEDP, EDS) were related but less sensitive parameters of dysfunction. However, when contractile function was reduced to about one half of normal, there was an associated marked increase in EDV, EDS, and LVEDP.

A wide spectrum of derangements was found ranging from virtually normal function in 18 patients with angina alone to severe dysfunction in 18 patients with myocardial infarction, mitral regurgitation, or heart failure.

Abnormalities in ventricular function were uniformly associated with myocardial infarction. Angina alone was associated with minimal or no ventricular dysfunction. Most patients with mitral regurgitation and all patients with heart failure had severe ventricular dysfunction manifested by an increase in EDV, LVM, and PSS, a marked decrease in SEF and SW, and a severe abnormality in contractile pattern.

Quantitative hemodynamic effects of heart rate in aortic regurgitation

The hemodynamic effect of varying heart rate was studied in eight patients with aortic regurgitation. At the subjects' resting sinus rhythm and at a higher heart rate induced with right atrial pacing, left ventricular and aortic pressures and Fick cardiac outputs (FCO) were measured, and left ventricular biplane angiocardiograms were performed. Left ventricular volumes and left ventricular minute flow (LVMF) were determined from the angiograms. Regurgitant flow was quantitated by subtracting the FCO from LVMF. Increased heart rate produced highly significant reductions in the left ventricular end-diastolic pressure (LVEDP), left ventricular end-diastolic volume, and stroke volume. End-diastolic circumferential stress (EDCS) and end-diastolic load (EDL) were abnormally high at resting sinus rhythm and were markedly decreased with increased heart rate. FCO increased, but no significant changes were observed in either the LVMF or the regurgitant flow per minute.

Bradycardia in aortic regurgitation may cause pulmonary congestion secondary to high LVEDP and may accelerate left ventricular dilatation secondary to markedly elevated EDCS and EDL. The possible benefits of preventing bradycardia in aortic regurgitation by chronic demand pacing is currently being tested.

Quantitative angiocardiography. IV. Relationships of left atrial and ventricular pressure and volume in mitral valve disease

Quantitative angiocardiographic methods have been used to determine left ventricular volume and left ventricular mass (LVM) in 100 patients with isolated mitral valve disease. Thirty-six patients had mitral stenosis (MS), 29 had mitral regurgitation (MR), and 35 had combined stenosis and regurgitation (MS + MR). Data on volume and LVM from these patients are presented and are related to standard flow and intracardiac pressure determinations and compared with normal values. In patients with MS, the mean end-diastolic volume per square meter of body surface area (EDV/m 2 ) was 72 ml/m 2 and was increased to 148 ml/m 2 in those with MR. EDV/m 2 correlated closely with the severity of regurgitation and less well with LV end-diastolic pressure. The mean LV stroke volume was slightly smaller than normal in patients with MS (38 ml/m 2 ) and was greatly increased in those with MR (88 ml/m 2 ). The LV stroke volume correlated closely with the severity of regurgitation, r = 0.928. The ejection fraction (EF) was low in 37% of patients with MS and in 22% of those with MS + MR and MR alone. Left atrial volume was larger than normal in all patients and, although generally larger in those with regurgitation, did not correlate with its severity. In contrast, cyclic left atrial volume change was correlated with the severity of mitral regurgitation, r = 0.785. The data are presented with cumulative distribution curves suitable for reference standards.

Human cardiovascular adjustments to rapid changes in skin temperature during exercise

In 11 normal men, central circulatory responses were measured while skin temperature was changed in a square-wave pattern during uninterrupted exercise (26% to 64% maximal oxygen consumption). Skin temperature was changed at 30-minute intervals, beginning at 32°C. On raising it to 38.2°C at low oxygen consumption (V · o 2 ), cardiac output increased 2.5 liters/min, and central blood volume, aortic mean pressure, and stroke volume fell (7%, 7%, and 11%, respectively). Right atrial mean pressure fell 2.2 and 2.3 mm Hg during control and heating periods, respectively. All variables returned to control levels when skin temperature was reduced toward 26.9°C. Raising it to 40°C reproduced these changes with a more clear-cut drop in right atrial mean pressure. Results indicated reduced peripheral venous tone and cutaneous pooling of blood during heating and rapid reversal on cooling. On raising skin temperature to 38.7°C at high V · o 2 , cardiac output increased 19% (3.1 liters/min), stroke volume decreased 14%, and central blood volume rose slightly. Aortic mean pressure fell during the control period and was maintained or rose during heating periods. On cooling, central blood volume and stroke volume rose, cardiac output remained elevated, and aortic mean pressure fell. Increases in cardiac output during heating were related to skin temperature and not to V · o 2 or body temperature. At high V · o 2 , circulatory adjustments favor metabolic rather than thermoregulatory demands.

Disparities between aortic and peripheral pulse pressures induced by upright exercise and vasomotor changes in man

Blood pressures were recorded simultaneously from the aortic arch and radial artery using two manometric systems with identical static and dynamic sensitivities. Measurements were made in four normal young men at rest and upright exercise requiring 29, 49, 78, and 100% of maximal oxygen uptake. Average radial arterial pressure rose from 133/66 mm Hg at rest to 236/58 mm Hg at maximal exercise. At the same time, average aortic pressures were 112/68 and 154/70 mm Hg, respectively. From rest to maximal exercise, pulse pressures at central and peripheral sites increased by factors of 1.95 and 2.60, respectively. Inducing reactive hyperemia in the arm abolished peripheral amplification. This amplification also diminished with time during prolonged heavy exercise. Mean pressures were nearly identical at the two sites at any oxygen uptake; mean pressures rose from 87 to 104 mm Hg from mild to maximal exercise. We conclude that estimates of stress on aortic and cerebral vessel walls and central baroreceptors would be grossly overestimated by use of peripheral pulse pressures.

Quantitative angiocardiography. II. The normal left atrial volume in man

Maximum and minimum volumes of the left atrium (LA) were calculated from the biplane angiocardiograms of 18 men and four women without significant heart disease.

The mean LA maximum volume was 63 cc ± 16 cc; the mean LA minimum volume was 31 cc±10 cc, and their difference, LA cyclic volume change, was 33 cc±13 cc. Larger LA volumes were associated with greater cyclic volume changes. LA cyclic volume changes constituted 38% of LV stroke volume.

No significant correlation between LA volumes and age, sex, surface area, heart rate, LV end-diastolic volume, LV stroke volume, or cardiac output was found.

Volume data in normal subjects support the thesis that the LA serves mainly as a reservoir and conduit for blood destined for the left ventricle and that its contractile function is less important. The relation of LA volume change to LV stroke volume appears abnormal in chronic mitral regurgitation and constrictive pericarditis.