Hemodynamic response to glyceryl trinitrate in a spray at rest and during exercise in a sitting position

Glyceryl trinitrate (GNT, 0.8 mg) was administered in a spray to 15 coronary patients of whom 7 had a pulmonary wedge pressure (PWP) greater than 16 mm Hg on exercise (subgroup I) and the others (subgroup II) had a normal PWP at rest and during exercise. At rest, GNT increased heart rate and decreased cardiac output, systolic index, stroke work index, right atrial pressure, pulmonary wedge and mean systemic pressures in all patients. Peripheral resistances did not change. During exercise, GNT lowered PWP, systemic arterial pressure and peripheral resistances in all cases. It increased cardiac output as well as systolic and stroke work indices only in patients of subgroup I. In subjects with coronary disease, no overt cardiac failure but elevated PWP on exercise, GNT in a spray can quickly improve exercise capacity and hemodynamic reserves and increase anginal threshold.

Pharmacokinetics of piperacillin in renal failure

Patients with chronic renal failure who received bolus doses of piperacillin maintained high serum levels for up to six hours. The percentage of the injected dose which was detectable in the urine in 24 hours was reduced proportionately to the severity of the renal failure.

[Long-term results in the isolated replacement of mitral and aortic valves]

This is a study of 85 valve replacements by mechanical prostheses, 41 of which were in the aortic position and 44 in the mitral position. The results were analysed from the standpoint of the immediate and late mortality, the morbidity, and thrombo-embolic complications. The influence of the severity factors (NYHA classification) on the operative risk and the late mortality has been evaluated. The maximum follow-up period was 8 years for the aortic replacements and 7 years for the mitral replacements. Actuarial graphs show that there is a 78.3% survival for aortic valve replacement and a 66% survival for mitral valve replacement. We feel that the shape of the survival curves is greatly influenced by the size of population studied. As soon as a plateau appears, the significance of the analysis is in doubt. It seems to us that calculation of the degree of confidence is essential if the good quality of the long-term results is not to be overestimated. The results of surgery must be assessed by comparing the survival curves of the operated patients with those of non-operated patients with the same risk factors. The conclusion emerges that prosthetic replacement of the mitral and aortic valves markedly improves the life expectancy of stage IV patients. We can see no indication for early surgery on the aortic valve. On the other hand, mitral valve replacement should be undertaken on stage III patients so that those with a poor life expectancy can be offered a better outlook. The way in which the mitral and aortic valve disorders carry a much greater mortality after the 6th decade should induce us to bring forward the indications for surgery in this age group in spite of the slightly greater immediate and late risk from operating on patients of this age.

Vectorcardiographic study of QRS loop in patients with left superior axis deviation and right bundle-branch block

Thirty-four elderly patients with right bundle-branch block and left axis deviation were studied vectorcardiographically utilizing the McFee-Parungao system. Atherosclerosis, arterial hypertension, angina pectoris, cardiac enlargement, and heart failure were common clinical features in this series. Moreover, intermittent advanced degree of atrioventricular block was present in 10 out of the 34 patients. The vectorcardiograms might be readily classified into two basic patterns, types A and B. In type A (19 cases), the frontal plane loop was open-faced. The initial vectors were directed anteriorly, inferiorly, and to the right. The mid-temporal vectors were located in the left postero-superior octant, and the late portion of the loop was inscribed anteriorly to the right with conspicuous conduction delay. Those vectorcardiographic features associate the characteristic patterns of left superior intraventricular block with complete right bundle-branch block. The type B vectorcardiograms (15 cases) demonstrated anterior clockwise loops in the horizontal plane and superior counterclockwise loops in the frontal plane. From a review of the published reports and from personal data, the authors assume that both vectorcardiographic patterns may result from an abnormal spread of excitation resulting from bilateral branch conduction disturbances.

Association of right bundle-branch block with left superior or inferior intraventricular block. Its relation to complete heart block and Adams-Stokes syndrome

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Arteriovenous fistula involving both coronary arteries and main pulmonary trunk

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