Biomedical subjects

B S Jenkins

Publications and source records attributed to B S Jenkins.

At least 55 records · Page 3Linked to original sources

PubMed1976

Enzymic analysis of cardiac biopsy material from patients with valvular heart-disease.

Cardiac tissue obtained by left-ventricular endomyocardial biopsy from patients with valvular heart-disease was assayed for marker enzyme activities of subcellular organelles and these were correlated with left ventricular function as assessed by haemodynamic studies. In patients with poor left ventricular function, calcium-dependent adenosine-triphosphatase (A.T.P.ase) activity, predominantly localised to the myofibrils, was strikingly reduced. Activity of lactate dehydrongenase, a cytosol enzyme, was significantly increased in tissue from patients with poor left ventricular function. The activity of enzymes associated with sarcolemma (5'-nucleotidase), mitochondria (glutamate dehydrogenase and monoamine oxidase), microsomes (neutral alpha-glucosidase), and lysosomes (acid phosphatase, N-acetyl-beta-glucosaminidase) was no different in patients with good or poor left ventricular function. It is suggested that reduced myofibrillary A.T.P.ase concentration is the biochemical basis for the impaired ventricular function.

Acid Phosphatase↗

PubMed1976

Logical approach to lignocaine therapy.

Plasma lignocaine concentrations were measured during and after lignocaine infusions administered for suppressing ventricular dysrhythmias. Twenty-four patients with a primary diagnosis of acute myocardial infarction without gross circulatory disturbance received, after a bolus of lignocaine, either 4 mg/min for 30 minutes, 2 mg/min for two hours, then 1 mg/min thereafter or 1 mg/min throughout. The higher dose regimen produced continous therapeutic levels of lignocaine, which were achieved only after four hours by the lower dose. On the other hand, in patients who had undergone cardiac surgery and who had circulatory and heptic dysfunction the lower dose regimen achieved therapeutic levels early. The plasma half life was longer in the surgical group (P less than 0.02). The higher initial infusion rate is recommended for patients with acute myocardial infarction without gross circulatory impairment.

Adult↗

PubMed1976

Assessment of left ventricular function by indices derived from aortic flow velocity.

The velocity and acceleration of aortic blood flow were measured by means of a catheter velocity probe in 40 patients during routine diagnostic cardiac catheterization. Ten different variables were derived from the aortic velocity measurements, and their ability to discriminate between good and bad left ventricular (LV) function was tested. By means of eight conventional indices of LV function derived from pressure, mean flow, and quantitative cineangiography, the patients were divided into 3 groups: group 1, good LV function; group 2, moderate LV function; group 3, poor LV function. Aortic peak velocity and maximal acceleration correlated well with stroke volume and were thus indices of LV pump function. Aortic peak velocity also showed a significant correlation with LV stroke work. Both aortic peak velocity and maximal acceleration failed to discriminate between the three groups of patients, and correlated poorly with conventional indices of LV function. The mean values of stroke volume differed significantly between groups 1 and 2, and between groups 1 and 3, and also correlated better with the conventional functional indices. The best discrimination between normal and abnormal LV function was provided by dividing stroke volume by maximal acceleration, but stroke volume divided by peak velocity discriminated better than stroke volume alone. Stroke volume divided by maximal acceleration also gave more significant individual correlations with the conventional functional indices than did any other variable derived from aortic velocity.

Adult↗

PubMed1976

Clinical, haemodynamic, and angiographic findings in Löffler's eosinophilic endocarditis.

Detailed haemodynamic and angiographic findings in Löffler's endocarditis are presented for the first time in a report of 3 cases of this rare disease. In 2 of the cases the right ventricular cavity was obliterated; in one of them this was shown by biopsy to be caused by organized thrombus. In the third case, there was progressive mitral regurgitation.

Blood Pressure↗

PubMed1976

An analysis of pulsus alternans in aortic stenosis.

Pulsus alternans was studied hemodynamically in 5 patients with calcific aortic stenosis. Left ventricular function was assessed by angiographic volume analysis and by force-velocity analysis. All cases showed alternation of max and min dP/dt and kVmax. Inconsistent factors were an alternating left ventricular enddiastolic pressure, alternating left ventricular enddiastolic volume, alternating left ventricular endsystolic volume, ejection fraction, enddiastolic wall stress and wall stiffness. All cases had a high ventricular mass, but the critical value of ventricular mass or the ratio of mass to left ventricular enddiastolic volume were also inconsistent. Pulses alternans is primarily due to alternating contractility.

Angiocardiography↗

PubMed1975

Effect of intermittent left anterior hemiblock on left ventricular function.

Studies of left ventricular function were performed during intermittent left anterior hemiblock, Max dP/dt and Vmax fell during left anterior hemiblock, with a rise in left ventricular end-diastolic pressure compared with a normally conducted beat.

Aortic Valve Insufficiency↗

PubMed1975