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Aims: In spinach, transplanting has replaced direct seeding but small containers may cause root restriction effects that would be decreased post - transplant yield. Although a single horm onal regulator (BAP) spray is effective in overcoming root restriction, the mechanisms involved are unknown. The aim of this work was to analyze spinach growth changes by the use of different plug cell volumes and BAP as foliar spray. Study Design: A rando mized complete block factorial design with three blocks was used. Place and Duration of Study: The experiments were conducted at the INTA Balcarce Experimental Station campus, Argentina (37 o 45 ′ S, 58° 18 ′ W and altitude 130 m) from 5

The induction of atrial systole by stimulation is a means of demonstrating insufficiency of myocardial perfusion, even where there is a normal coronary flow under basal conditions in a genuine case of coronary atherosclerosis. The method, which entailed the use of radiocardiography with potassium 42, was first checked for reproducibility. The coronary flow was then measured under basal conditions, and subsequently during or after atrial stimulation at 150/min. in a group of 50 controls and coronary patients. Under atrial stimulation, the value increases by an average of 15 per cent in the controls, and decreases by an average of 32 per cent in cardiac patients with vessels which are patent on coronary angiography. The coronary moiety of the cardiac output increases by an average of 27 per cent in the controls, but does not change significantly in the coronary group. After aorto-coronary by-pass, the coronary moiety of the cardiac output is increased significantly during stimulation when the by-pass is patent.

There is no controversy about the prosthetic replacement of the aortic valve in cases in which there is a disorder of function or cardiac failure, or in cases with a tight aortic stenosis, even if it appears to be well-tolerated clinically. It is especially critical in cases of aortic incompetence with marked cardiac enlargement, but the problems are not overwhelming. The indications for operation in very advanced cases with cardiac failure which is refractory, or in aged patients, are discussed.

Ninety symptomatic patients aged between 16 and 90 years were investigated by ambulatory continuous 24 hour electrocardiography. 75 of these patients underwent endocavitary exploration of atrioventricular conduction and sinus node function within 48 hour of ambulatory electrocardiography. Symptoms occurred during the recording in 30% patients, enabling the mechanism of the malaise to be determined. Every time that abnormalities in the zone surrounding the Tawara node were demonstrated by endocavitary recordings, the 24 hour electrocardiogramme showed the symptoms to be due to other causes than complete heart block. In 70% patients no symptoms were experienced but 58% of them had cardiac arrhythmias and particularly sinus node dysfunction (24 out of 37 patients) on the 24 hour electrocardiogramme. Comparing the results of these two methods of investigation, continuous electrocardiography appears to be a better technique for the diagnosis of sinus node dysfunction but endocavitary study of sinus node function would seem more suited to determine its severity. Endocavitary recordings seem more reliable in the investigation of paroxysmal atrioventricular blocks. These results demonstrate the complementary nature of these two methods in determining the causes of syncope and dizziness.

The authors report a case of Steinert's disease with disordered sino-atrial and atrio-ventricular conduction. The presence of sudden syncopal attacks and the absence of a cardiomyopathy (excluded by right- and leftsided haemodynamic studies and coronary arteriography) indicated the insertion of a definitive intra-cavitary pacemaker, especially as the life expectancy of this 54 year old patient did not seem to have been significantly reduced by his disease.

The authors report the case of a 19 year old woman with supravalvar aortic stenosis and hypoplasia of the ascending aorta with stenosis at the origin of the innominate artery. This was a sporadic form, without mental deficiency nor facial dysmorphia. No similar case was found in the family. The patient had three attacks of bacterial endocarditis over a period of 3 years and became cured without any cardiac sequelae. In view of the onset of left ventricular failure and sequelae. In view of the onset of left ventricular failure and syncope, operation was decided. A lozange-shaped patch was placed on the aorta from the narrowed supravalvar part to the origin of the innominate artery and prolonged on the latter vessel after relief of the stenosis. This gave an excellent result.

Selective intracoronary injection of microspheres labelled with radioactive substances which emit gamma rays with different energy levels (Indium 113 m and Technetium 99 m) allows us to explore by scintigraphic methods the areas of distribution of the two coronary arteries. Having been carefully calibrated, the particles are injected in limited numbers, and block the precapillary arterioles, where they gradually diminish in number. Scintigraphic examination is carried out in various projections (anteroposterior, left anterior oblique and right anterior oblique) immediately after coronary arteriography. Coronary scintigraphy allows us to establish the integrity of the distribution network of a coronary trunk which appears normal on coronary arteriography, to visualise the diminution of flow caused by a stenosed but patent trunk, and to visualise the extent of the collateral circulation and the quality of revascularisation achieved by an aorto-coronary bypass operation.

The authors studied systolic murmurs in 89 cases, 50 of aortic stenosis, 14 cases of obstructive cardiomyopathy and 20 cases of mitral incompetence. This systolic murmur is characterised by its exceptional intensity, its raspy character at the base, becoming softer at the apex and in the axilla, the presence of a thrill and irradiation into the neck in 50 to 75% of cases. The etiological diagnosis was ensured precisely by 1) pharmaco-dynamic tests: amyl nitrite accentuates the systolic ejection murmurs and attenuates murmurs due to mitral regurgitation. 2) careful analysis of diastole: a systolic murmur extending into early diastole, a third sound or an opening snap and a low-pitched diastolic murmur, suggest mitral incompetence. A high-pitched diastolic murmur is in favour of aortic stenosis. 3) the carotid arteriogram and catheterisation show the characteristic abnormalities of the carotid arteriogram found in aortic valve disease and the existence of a trans-aortic or intra-ventricular pressure gradient, when there is an obstruction to left ventricular jection. The F wave of the apex cardiogram or left atrial reflux of the contrast medium during cineangiocardiography, confirm mitral incompetence. The main phono-hemodynamic and phono-anatomical correlations have been emphasized: 1. The intensity of the systolic murmur is directly proportional to the degree of obstructive cardiomyopathy or mitral incompetence, but does not parallel the degree of the sub-valvular apparatus. 3. The maximum intensity of the murmur occurs all the later when the stenosis is tight, whilst it is earlier in severe obstructive cardio-myopathy. 4. The lozange shape of the murmur of mitral incompetence on phono-cardiography is, above all, due to those cases with lesions of the sub-valvular apparatus. Finally, a study of the sound recorded by the Allard-Laurens micromanometer permitted us to determine the mechanism of this irradiating systolic murmur.

Although greater than in patients with stabilised coronary insufficiency, the risks of carrying out coronary arteriography during the period of a threatened infarction are still modest in the hands of an experienced team. In a series of 66 such investigations under these conditions over an 18 month period, there were no deaths as immediate sequelae. Three myocardial infarctions occurred, one of which was probably encouraged by ceasing the propranolol prior to arteriography. Analysis of the results confirms the frequency of lesions affecting all three trunks (47% of cases), the anterior descending branch being the most commonly affected. A collateral circulation was established in 23% of cases. Ventriculography was normal in one third of cases. The mean value for the ventricular ejection fraction was 0.57 over the entire series. In 58% of cases, all the arteriographic and ventriculographic criteria of operability were satisfied. It therefore appears that coronary arteriography is justifiable during the period of threatened infarction; it may be undertaken at an early stage if the angina does not respond to medical treatment. It is always best to carry it out several days after cessation of the pain where possible. The investigation may lead to urgent surgical intervention.

Twenty-one patients were treated during the acute stage of a myocardial infarction for failure of the left or right ventricle. The systematic use of varying rates of flow of intravenous trinitrin (between 0.6 and 4.8 mg/h) was designed to find out for each patient the optimal effect on the cardiac index. The fall in pulmonary capillary pressure, obtained within 10 to 15 minutes, is proportional to the flow rate of trinitrin, and reaches 48% of its original value at a perfusion rate of 4.8 mg/h. The lowering of systemic arterial pressure is also proportional to the flow rate, and reaches 13% at a flow of 4.8 mg/h. The cardiac index and systolic index were significantly improved at flow rates of 1.2 to 2.4 mg/h, and lowered the pulmonary capillary pressure to levels of 17.6 mm of mercury and 15.3 mm of mercury respectively. Trinitrin given intravenously is very well tolerated, but it often become less effective after 24 hours of treatment, which implies that haemodynamic measurements must be made several times a day, and the speed of infusion often increased. The improvement in immediate and late prognosis is discussed relative to the initial values and Weber's index of survival.

Five uraemic patients who developed progressive cardiac failure with clinical evidence of congestive cardiomyopathy at the start or during haemodialysis treatment were studied. The diagnosis of cardiomyopathy, for which there was no apparent cause, was confirmed by angiocardiographic and haemodynamic studies. These showed a significant increase in left ventricular end-diastolic volume over normal values obtained in 12 patients without uraemia. The mean velocity of myocardial fibre shortening was significantly decreased, as was the index of normalised rigidity. Three of the five patients presented the complete picture of the disease. The other two also had considerable ventricular dilatation and a decreased index of normalised rigidity but normal ejection fraction and only moderately decreased myocardial contractility indices. This suggests that there may be primary involvement of normalised heart muscle rigidity followed by secondary changes in myocardial contractility in uraemic patients with congestive cardiomyopathy.

A 64-year-old man, who underwent double valve replacement for mitral and aortic incompetence due to infective endocarditis, presented with a coronary embolism of a fragment of mitral papillary muscle in the immediate post-operative period. The diagnosis, suggested by the sudden development of acute myocardial insufficiency during ventricular filling, was confirmed by the absence of clinical or electrical improvement during circulatory assistance and by surgical exploration of the left coronary artery. Complete recovery after embolectomy emphasises the value of the association of circulatory assistance and immediate myocardial revascularisation.

The sinus function of 60 patients was studied by atrial stimulation at a fixed rate, and also at a rate linked with the preceding sinus cycle. These patients were divided into 3 groups according to the surface-recorded ECG; 10 had clear evidence of sinus dysfunction, 23 had an isolated sinus bradycardia, and 27 were considered as controls a their sinus rate was above 60/min., with a normal PR interval. Calculation of the limits of tolerance showed that at the 5% level, 95% of the values for all the controls fell between 96.8 and 568.7 ms for the corrected post-stimulatory pause, and between 114.5 and 434.3 ms for the corrected maximum return cycle. A study of the distribution zones of the graph CT/CR-AA/AA proved that an absent zone II is a pathological finding. In the group of sinus bradycardias the limits of what constitutes pathology are less clear, and the situation is not improved by noting whether atrial "echos" are present or absent. Because there is a narrow positive correlation between the values given by the two methods, the physio-pathology of sinus dysfunction can be discussed.

A cine-angiographic study was carried out in eleven patients with major aortic incompetence, in two of whom there was an associated aortic stenosis. The ventricular end-diastolic volume is always greatly increased, disproportionately to the modest increase in end-diastolic pressure. The pressure-volume relationship during filling is therefore altered, and makes it possible for a normal end-diastolic compliance (dV/dP) TD to be preserved. The indices of contractility are markedly altered, despite the recent appearance of signs of poor tolerance. These findings argue in favour of a full haemodynamic investigation and of early corrective surgery.

Repeated recordings were made of the apexcardiogram throughout the first month after myocardial infarction in 30 patients. The classical timed intervals of the systolic wave are open to some criticism. The systolic waveforms are important. In the majority of transmural anterior infarctions there is a rounded appearance to the beginning of the wave which seems to prolong the electromechanical latency, followed by a late systolic bulge, or a domed waveform. This signifies a non-contractile area, and not neccessarily an ectasia. The early diastolic "peaktrough" appearance, found very frequently wherever the necrosis is situated, is indicative of asynergic contraction of the left ventricle. All of the diastolic phases are altered, probably by increased parietal stiffness: the TRI is lengthened; the "F" wave is flattened (and often absent later on in the condition), its duration is shortened over the anterior positions, and it may contain a shallow dip if there is LVF; the stasis wave is very feeble; the "a" wave is large when the infarct is extensive, or when there is LVF, or when there is longstanding hypertension. Enlargement of the "a" wave is especially indicative of a lowering of the performance of the left ventricle.

The hyperemic response induced by the tri-iodinated contrast agent injection for coronarography assesses functional value of the arteriolar areas of coronary distribution. The intracoronary injection of two kinds of micropheres labeled with gamma emitter radionuclides of different levels of energy (99m-Technetium and 113m-Indium) provides comparison of the studied areas-scintigraphies at rest and during hyperemia.

Pericarditis is the commonest cardiac manifestation of rhumatoid arthritis. It is often clinically latent but it may evolve to constriction or less often to tamponade. The case presented is of a 60 year-old woman with a 5 year history of seropositive nodular rhumatoid arthritis in whom bilateral pleural effusions and constrictive pericarditis were observed after sudden termination of corticotherapy. She was treated successfully by pericardectomy. This complication is far from being exceptional (55 cases already reported). It justifies a systematic search for pericarditis in rhumatoid arthritis, especially by echocardiography.

Advantage may be taken of the hyperaemic response to the iodine contained in the contrast medium injected during coronary angiography to assess the functional value of the coronary tree using radioactive microspheres. This series comprises 73 selective coronary scans performed in the resting state (113 m In marked microspheres) and during the hyperaemic phase (99 m TC marked microspheres) in 70 patients. A positive hyperaemic response distal to severe truncular stenosis indicates a good distal arteriolar bed and collateral circulation for aorto-coronary bypass grafting. After aorto-coronary bypass (23 cases), the hyperaemic response gives an indication of the functional value of the revascularised myocardium. In 71% cases, the results correlate well with the measurement of the peroperative blood flow through the graft. It is usually positive when the bypass graft is implanted with good distal arterial run off.

Aneurysms of Valvsalva sinus unruptured into a cavity, but developing into the membranous and even muscular interventricular septum are exceptional. Two cases illustrating this fact are reported. In one of them, a massive mitral incompetence by elongated chordae tendinae related to the presence of a voluminous intra-septal pouch. Atrio-ventricular and intraventricular conduction disturbances were present in both patients. The interest of supra-valvar angiography which makes it possible to advise operation before the eventual rupture is underlined.

The combination of radiocardiography with scintigraphy of the cavities of the heart allows us to calculate the effective systemic ejection fraction. The systolic volume effectively ejected into the systemic circulation is obtained from radiocardiography using Stewart-Hamilton's principle. It is correlated with the left ventricular end-diastolic volume as calculated by planimetry on the scintigraphic record of the cavities of the heart, making due allowance for the geometrical axis of the heart. The ejection fraction measured by this isotope method has been compared with the ejection fraction measured by selective left ventricular cineangiography, both measurements being carried out at an interval of less than 48 hours in 100 patients without valvular disease. The results show an excellent correlation between the two methods (r = 0.94). In the 15 cases where the haemodynamic status of the ventricule appeared to be normal, the ejection fraction meastured by the two techniques was 0.65 +/- 0.04 and 0.66 +/- 0.04 respectively. In those patients with valve disorders with incompetence, the effective systemic ejection fraction is always lower than the total ejection fraction given by cineangiography. The difference corresponds with the fraction of the blood volume which is regurgitated.

In order to evaluate the importance of the indices of ventricular rigidity and compliance (k=dP/dV.P and dV/dP), three groups of patients were studied and compared. A simplified method of calculating the diastolic compliance made use of the values of end-diastolic volume (EDV) measured by cineangiography, and of end-diastolic pressure (EDP), using the assumption that the relationship P-V is an exponential one arising from the ordinate: 0.43 mmHg. The correlation between EDP and EDV, which was positive in 19 coronary artery patients, was in fact negative in 11 patients with obstructive cardiomyopathy (OCM), and insignificant in 12 control patients. There were multiple correlations between k, EDPs and EDVs in 11 OCMs, and none in the two other groups. The ratio dV/dP decreased in end-diastole both in the OCM group and in the coronary group, and did not reflect the difference in pathology between these two groups. On the other hand k was increased in the patients with OCM, normal in the coronary patients, and represented in the former a primary modification in the relationship P-V and a primary increase in diastolic rigidity.

The authors report a clinical and phonocardiographic study of functional aortic systolic murmurs in 26 elderly patients, in 19 of which the lesion was confirmed pathologically. Systolic murmurs radiating across the chest in elderly have the same clinical characteristics as aortic stenosis from which they may, however, be distinguished owing to the: absence of a thrill during systole. The brief duration and the proto-meso-systolic position of the murmur with early inscription of maximal oscillations on the phonocardiogram. Conversion of the second aortic sound. Almost constant absence of a diastolic murmur. Normal carotid arteriogram, including normal ejection time after correction and time of half rise. "Innocent" systolic murmurs are due to calcification of the aortic valve without stenosis, and/or dilatation of the ascending aorta. There is no systolic pressure gradient between the left ventricle and the aorta during cardiac catheterisation. No lesions were found in the mitral valve suggesting mitral incompetence, therefore, we consider the term mitro-aortic murmur used by Huchard should be dropped; Radiation of the murmur from the apex of the heart up into the neck may be explained by the simultaneous occurrence of anatomical changes due to age and/or hypertension and by the vibratory nature of the murmurs which become propagated above and below their origin, as shown by the intracardiac recordings.