The Orbiting Carbon Observatory-2 early science investigations of regional carbon dioxide fluxes.

NASA's Orbiting Carbon Observatory-2 (OCO-2) mission was motivated by the need to diagnose how the increasing concentration of atmospheric carbon dioxide (CO2) is altering the productivity of the biosphere and the uptake of CO2 by the oceans. Launched on 2 July 2014, OCO-2 provides retrievals of the column-averaged CO2 dry-air mole fraction ([Formula: see text]) as well as the fluorescence from chlorophyll in terrestrial plants. The seasonal pattern of uptake by the terrestrial biosphere is recorded in fluorescence and the drawdown of [Formula: see text] during summer. Launched just before one of the most intense El Niños of the past century, OCO-2 measurements of [Formula: see text] and fluorescence record the impact of the large change in ocean temperature and rainfall on uptake and release of CO2 by the oceans and biosphere.

Comparison of some criteria for diagnosing a myocardial infarction after aorto-coronary bypass grafting (CABG).

The incidence of myocardial infarction during a 1-year follow-up period after coronary bypass surgery (CABG), i.e. a recent myocardial infarction (RMI), was studied in 86 patients. Different criteria for the diagnosis of a RMI were compared. Clinical observation, including ECG and serum enzyme analysis, diagnosed RMI in 8% of patients. Specific ECG changes indicating RMI (ECGsp) occurred in 12% of cases, and if less specific ECG changes were also taken into account (ECGsp+nonsp) RMI was found in 30% of cases. Asynergy, detected by two-plane ventriculography, indicated RMI in 24% of the patients, and was probably the most valid of the criteria examined. The differences in diagnostic accuracy of the various criteria highlight the importance of defining diagnostic criteria.

Effects of digitalis, anti-anginal drugs and arterial hypertension on the relationships between exercise ECG and angiocardiographic variables and on the diagnostic accuracy of exercise ECG in patients with coronary heart disease.

We have previously found a statistically significant correlation between some exercise ECG variables and angiocardiographic scores used to evaluate the extent and type of coronary heart disease (CHD). In the present study we examined the effects of digitalis, beta-adrenergic blockers, slow release nitrates, calcium channel blockers, presence of arterial hypertension (AHT), and angiocardiographic changes on the exercise ECG variables. The effects of drugs and AHT were small as compared to the effects of the angiocardiographically detected pathological changes caused by the CHD. Sensitivity and specificity of the exercise ECG ST criteria in identifying patients with an angiocardiographic criterion indicating coronary insufficiency were not much different in the whole group and in the subsets with AHT or medication with digitalis and anti-anginal drugs.

On-line computerized vectorcardiography monitoring of myocardial ischemia during coronary angioplasty: comparison with 12-lead electrocardiography.

BACKGROUND: With new interventions minimizing ischemic myocardial injury, accurate and reliable techniques for the detection and continuous monitoring of myocardial ischemia are essential. We compared two techniques used for the detection of myocardial ischemia during coronary angioplasty: on-line computerized vectorcardiographic (cVCG) monitoring and the standard electrocardiography (ECG) leads or the complete 12-lead ECG. METHODS: Thirty patients scheduled for routine angioplasty were included in the study. cVCG was recorded continuously. The electrodes were placed according to the lead system described by Frank and connected to a computerized system for on-line vectorcardiography. A 12-lead ECG was recorded simultaneously. The absolute variable spatial ST vector magnitude (ST-VM) and the relative variable spatial ST change vector magnitude (STC-VM) were calculated and compared with the standard 12-lead ECG for the detection of ischemia. RESULTS: The sum of deviation in ST segment in all 12 standard ECG leads correlated closely with STC-VM, irrespective of which artery was occluded. STC-VM indicated ischemia during the first balloon inflation in 87% of the patients and demonstrated ischemia in more patients than the standard 12-lead ECG. Myocardial ischemia was not demonstrated by ST-VM in five out of 26 patients with ischemia according to STC-VM. In these cases, mainly directional vector changes and fewer changes in magnitude were observed. CONCLUSION: Compared with 12-lead ECG, on-line cVCG is a more sensitive method of detecting myocardial ischemia during coronary angioplasty and the reading is easier and faster. Our results support STC-VM > or = 0.050 mV as the criterion for ischemia during angioplasty; ST-VM should be applied together with STC-VM.

Relationships between exercise ECG and angiocardiographic indices of coronary insufficiency and myocardial fibrosis in coronary heart disease.

Patients with coronary heart disease were examined with exercise ECG and angiocardiography. Maximum work capacity expressed as a percentage of the predicted normal exercise tolerance (Wmax%) was significantly associated with the angiocardiographic score of the myocardial mass subserved by obstructed coronary arteries (MCOS). Variables related to myocardial fibrosis (MF) such as post infarction ECG signs, the left ventricular wall motion score (LVMS) and the ejection fraction of the left ventricle (LVEF) correlated significantly as did variables related to reversible myocardial ischaemia or coronary insufficiency (CI), such as ST depression during exercise (STdepr), ST/W and ST/HR indices, effort angina (EA/W) index, the extent of collaterals (CollS), and 'MCOS-LVMS'. MF variables correlated weakly with CI variables. Wmax% covariated with the variables related to both CI and MF, and most closely with MCOS. Discrepancies between results of exercise ECG and angiocardiography have to some extent been overcome by comparing appropriate parameters.

Quantitative assessment of aortic regurgitation by combined two-dimensional, continuous-wave and colour flow Doppler measurements.

The width of the regurgitant jet at the aortic valve plane, i.e. the core flow diameter, the ratio of the jet width to the left ventricular outflow diameter, the regurgitant volume and regurgitant fraction were determined using two-dimensional, continuous wave and colour flow Doppler echocardiography. The relationship between the non-invasive measurements and semiquantitative angiographic grading of the regurgitant flow (1 + to 4+) was examined in a primary group of 20 patients with chronic aortic regurgitation. Cut-off points for the non-invasive measurements were selected so as to separate patients with mild or moderate regurgitation (1+ or 2+) from patients with moderately severe or severe regurgitation (3+ or 4+). These cut-off points were prospectively applied in a new group of 35 patients with aortic regurgitation to predict the angiographic grading. Jet width correctly predicted the angiographic grading in 86% of cases, the ratio of the jet width to the outflow diameter in 83% of cases, the regurgitant volume in 86% of cases and the regurgitant fraction in 91% of cases. We conclude that the severity of aortic regurgitation as determined by angiographic grading can be estimated with reasonable accuracy by non-invasive techniques based on colour flow imaging.

Complete occlusion of the left main coronary artery: clinical and angiographic observations in five cases.

Involvement of the left main coronary artery is observed in approximately 5 to 8% of patients with coronary artery lesions detected by coronary angiography, but occlusion of the left main artery is a very infrequent finding. Out of approximately 4000 patients undergoing coronary angiography, four men and one woman, 37 to 60 years old, showed total occlusion of this vessel. Four of them had angina pectoris and three had had a myocardial infarction. All five showed deep ST depression in V 2(or 3)-6 during bicycle exercise testing. Apart from the left main artery occlusion, all had significant obstructive lesions in other coronary vessels, including the right coronary artery or its major branches. There was collateral circulation from the right coronary artery in all patients. Left ventricular function was well preserved in three patients and markedly impaired in two. Four patients underwent bypass surgery and they have been followed for 10 to 28 months. Three are free of angina and one has only minimal angina. One patient refused surgery and he continued to have severe angina despite intense medical treatment. He died suddenly after 30 months follow-up. In patients with complete occlusion of the left main coronary artery, development of adequate collateral flow seems important in preserving left ventricular function, but collaterals are usually insufficient to prevent angina. Moreover, associated obstructive lesions in other coronary arteries constitute a potential threat to the collateral circulation. Effective symptomatic relief is obtained by coronary bypass grafting, and revascularization may also improve prognosis in this subset of patients with coronary heart disease.

Pulmonary-artery cineangiocardiography and echocardiography for detection of cardiac sources of cerebral embolism.

Sixty-two patients with ischemic stroke possibly due to embolism of cardiac origin were investigated by pulmonary artery-cineangiography (PACAC) and echocardiography (UCG) to detect intracardiac thrombi. The proportion of intracardiac thrombi found by PACAC was 31% and by UCG 15%. The presence or absence of atrial fibrillation correlated well with PACAC findings of an intraventricular clot but poorly with UCG. Similarly, there was a significant association between ischemic heart disease and intraventricular thrombi detected by PACAC investigations but not with the results obtained by UCG. PACAC seems superior to UCG in the detection of intracardiac thrombi after possible embolic stroke.

Noninvasive determination of the valvar area in aortic valve disease by Doppler echocardiography and radionuclide angiography.

To assess the severity of outlfow obstruction in patients with aortic valve disease, the aortic valvar area was noninvasively determined in 22 patients with isolated aortic stenosis or combined stenosis and regurgitation. The ejection time (ET), maximal velocity (Vmax), and systolic velocity integral (SVI) of the aortic flow was obtained by continuous wave Doppler ultrasound. Left ventricular stroke volume (SV) was determined by radionuclide angiography, using a counts-based nongeometric technique with individual attenuation correction. Aortic valve area (AVA) was calculated using a modified Gorlin formula; AVA = SV/(71.2 X ET X Vmax), and also by dividing the stroke volume by the systolic velocity integral; AVA = SV/SVI. The two noninvasive determinations correlated closely with the valve areas obtained by invasive measurements; r = 0.95, SEE = +/- 0.13 cm2 by the modified Gorlin formula, and r = 0.94, SEE = +/- 0.14 cm2 by the integration method. The two noninvasive calculations showed almost uniform results; r = 0.98, SEE = +/- 0.09 cm2. In conclusion, aortic valve area can be determined with reasonable accuracy by combining Doppler echocardiography and radionuclide angiography. This noninvasive approach may reduce the need for invasive measurements in patients with suspected aortic valve disease. In addition, radionuclide angiography provides important information about left ventricular function.

Relationships between coronary artery obstruction, asynergy, presence of collaterals and the ejection fraction of the left ventricle in patients with coronary heart disease.

Cardioangiographic scores of coronary artery obstructions and corresponding myocardial involvement (MCOS), presence of collaterals (CollS), and asynergy of the left ventricular wall (LVMS) as well as the left ventricular ejection fraction (EF) were examined in 67 patients with coronary heart disease. A covariation was found between LVMS, EF, ECG changes, and a history indicating a previous myocardial infarction (MI). In a multiple regression analysis the EF covariated with LVMS but not with MCOS and CollS. LVMS indicated a previous MI with at least the same sensitivity and specificity as EF. MCOS and CollS give additional information. Collaterals as well as a high MCOS in relation to the LVMS indicate obstruction of coronary arteries which subserve 'non-fibrotic' myocardium. A patient with a high MCOS and CollS and a low LVMS should be expected to gain most functional improvement from coronary bypass surgery. The scores MCOS, CollS and LVMS are comparatively easy to determine and give a more diversified picture of the state of the myocardium than the EF alone.

Left ventricular asynergy score as an indicator of previous myocardial infarction.

Sixty-eight patients with coronary heart disease (CHD) i.e. a history of angina of effort and/or previous 'possible infarction' were examined inter alia with ECG and cinecardioangiography. A system of scoring was designed which allowed a semiquantitative estimate of the left ventricular asynergy from cinecardioangiography--the left ventricular motion score (LVMS). The LVMS was associated with the presence of a previous myocardial infarction (MI), as indicated by the history and ECG findings. The ECG changes specific for a previous MI were associated with high LVMS values and unspecific or absent ECG changes with low LVMS values. Decision thresholds for ECG changes and asynergy in diagnosing a previous MI were evaluated by means of a ROC analysis. The accuracy of ECG in detecting a previous MI was slightly higher when asynergy indicated a 'true MI' than when autopsy result did so in a comparable group. Therefore the accuracy of asynergy (LVMS greater than or equal to 1) in detecting a previous MI or myocardial fibrosis in patients with CHD should be at least comparable with that of autopsy (scar greater than 1 cm).

Prevalence of coronary artery disease in patients with valvular heart disease.

To evaluate the usefulness of preoperatie coronary angiography in patients undergoing preoperative investigation because of valvular heart disease, we performed coronary angiography in a consecutive series of 329 patients. The prevalence of significant coronary artery disease was 32%. Asymptomatic coronary artery disease was present in 13%. Angina pectoris proved to be a poor predictor of coronary artery disease in aortic valve disease. In mitral valve disease, however, the specificity was high. A cost-benefit calculation was carried out in order to assess what advantage routine coronary angiography might have. According to this, coronary angiography should be performed in all patients suffering from valvular heart disease with angina pectoris, whereas it can be omitted in younger patients without angina. A cut-off point of 60 years seems appropriate for aortic valve disease and 65 years for mitral valve disease.

Detection of coronary artery disease by means of exercise ECG in patients with aortic stenosis.

In a preoperative evaluation, 35 consecutive patients with aortic stenosis were examined by means of exercise ECG, Doppler and direct manometric measurements of the pressure difference over the aortic valve (delta P) and angiocardiography. Coronary artery disease (CAD) was found in 43% of the patients. Those with CAD had a lower mean maximum physical performance expressed as a percentage of the normal value (Wmax%), larger ST depressions and a higher effort angina (EA) score at the exercise test than the non-CAD group. Mean delta P was equal in the two groups. A myocardial coronary obstruction score covariated positively with a coronary insufficiency index (CT index = 100 X STdepr/Wmax%) and the EA score. There was no correlation between delta P and the EA score or the CI index. A CI index less than 3 and an EA score less than 2 were found in 49% of the patients and excluded the presence of CAD with a predictive accuracy of 88%, a better diagnostic complement to coronary arteriography than a history of EA.

Decreased removal of triglycerides from the blood--a mechanism for the hypertriglyceridemia in male patients with coronary artery disease.

We determined serum apolipoprotein A I and A II concentrations and triglyceride and cholesterol concentrations in serum lipoprotein density classes in 28 male patients with severe ischaemic heart disease (IHD) and with angiographically verified coronary artery disease (CAD) and in age-matched controls. Both triglyceride and cholesterol concentrations in very low density lipoproteins and in low density lipoproteins were higher in IHD-patients than in the controls. The triglyceride but not the cholesterol concentration in serum was higher in IHD-patients than in the controls. The cholesterol in high density lipoproteins and the serum apolipoprotein A I concentration were lower in IHD-patients than in the controls. At least in part the higher triglyceride concentration in very low density lipoproteins could be attributed to a decreased removal of triglycerides from the blood since the fractional removal rate of an i.v. injected artificial triglyceride emulsion (Intralipid) was slower in IHD-patients than in the controls.

Pulmonary-artery cineangiocardiography to demonstrate cardiac thrombi in patients with cerebral infarction.

The usefulness of pulmonary-artery cineangiocardiography (PACAC) to demonstrate intracardiac thrombi in patients with cerebral infarctions of possible embolic origin has been explored. PACAC was performed in 60 patients (mean age 74 years) with sudden onset of permanent neurological deficits in whom CT scan and CSF analyses had excluded intracerebral hemorrhage. Opacification of the left atrium was excellent in 52 (87%) investigations, acceptable in 7 and poor in 1. Among 33 patients with chronic atrial fibrillation, an atrial thrombus was demonstrated in 8 (24%) and a suspected thrombus in 3. Atrial clot was also demonstrated in a patient with intermittent atrial fibrillation. In 4 out of 14 patients with previous myocardial infarction, a ventricular thrombus was demonstrated. Ventricular clots were detected in 2 of 46 patients without known previous myocardial infarction. No major complications occurred during the investigation. PACAC can be to used in the search for atrial or ventricular thrombi when cardiac source of a cerebral embolus is suspected. About 1 out of 3 patients with atrial fibrillation has remaining intracardiac thrombus after stroke.

Cardiopulmonary function in sarcoidosis.

Hemodynamics, angiocardiographic findings and lung function were evaluated in 10 patients with clinically, radiologically and histopathologically established sarcoidosis. All 10 patients had cardiac symptoms and/or abnormal ECG. Right and left heart catheterization, angiocardiography, spirometry and diffusion capacity were performed in all patients. Pulmonary hypertension was present in the two patients with stage III sarcoidosis and in 7 of 8 patients with stages I and II. Right ventricular end-diastolic pressure was elevated in 6 patients. Seven patients had findings compatible with a failing left ventricle with elevated end-diastolic pressure and/or elevated pulmonary capillary wedge pressure. None of the patients had entirely normal hemodynamic findings. Angiocardiography showed a low ejection fraction in 6 patients but no wall asynergy. Right ventricular angiography and coronary angiography were normal in all patients. Findings compatible with failure of the left and right ventricle of the heart was common in our sarcoid patients with cardiac symptoms and/or abnormal ECG. Impairment of the pulmonary function does not seem to be the only reason for the hemodynamic findings, thus indicating the possibility of myocardial sarcoidosis.

Comparative interest of two coaxial viscometers: ecktacytometer and low shear 30.

We have studied some rheological parameters in different clinical status by using two coaxial viscometers. The Contraves Low Shear sinus 30 allows available shear rates range from gamma (128s-1 to 0,0175 s-1), and the parameters studied were viscoelastiticy, thixotropy and blood viscosity. The Ecktacytometer+ is another method for measuring cell deformation in couette flow. The aim of our study was to compare these two technics, to consider their clinical interest and finally to visualize an eventual correlation.

Assessment of deep venous insufficiency by ascending phlebography.

Retrograde femoral phlebography performed in the supine and erect positions are compared. In deep venous insufficiency, the contrast medium passes considerably farther down in the retrograde direction in examinations with the patient in the erect position. A comparison was made between ascending and retrograde techniques in order to find out what predictive value conventional ascending phlebography of the lower limb may have with regard to the function of the valves in the femoral vein. Layering of the contrast medium in the valvular sinus is a very reliable sign of valvular competence and was observed in two-thirds of the cases without deep venous insufficiency. This figure can be increased by a slight modification of the method of examination. Absence of layering does not necessarily indicate deep venous insufficiency.