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Biomedical subjects

J Bathen

Publications and source records attributed to J Bathen.

7 recordsLinked to original sources

Impact of changes in heart rate and stroke volume on the cross sectional flow velocity distribution of diastolic mitral blood flow. A study on 6 patients with pacemakers programmed at different heart rates.

The effect of changes in stroke volume on the cross sectional velocity distribution in the mitral orifice during passive mitral inflow was studied in six patients with total atrioventricular block, atrial fibrillation and VVI pacemakers during periods with different heart rates. The time velocity integrals recorded both in the left ventricular outflow tract and at the mitral orifice decreased significantly as the heart rate was increased from 60 to 80 and from 80 to 100 beats per minute. Instantaneous cross sectional flow velocity profiles were constructed by time interpolation of the velocity data from each point in sequentially delayed two dimensional digital ultrasound maps. Each patient had a characteristic cross sectional flow velocity profile in the mitral orifice recorded at the level of the leaflet tips in a four chamber view. The velocity profiles varied between the patients. With increase in heart rate only minimal changes in the flow profiles from individual patients were seen. The maximum velocity through the mitral orifice overestimated the cross sectional mean velocity at the same time by a factor of 1.4-1.9. The maximum time velocity integral overestimated the cross sectional mean by a factor of 1.4-1.8. The observed cross sectional skew varied between patients but did not change significantly with increasing heart rate and decrease in stroke volume.

Aged

Use of a simulation model to study the acute haemodynamic effects of diazoxide in man.

The acute haemodynamic effects of injected diazoxide (Hyperstat Schering) have been studied in 8 hypertensive subjects. Aortic blood pressure was measured and cardiac output and peripheral conductance were assessed continuously using a simulation model. In six of the patients pulmonary artery end-diastolic pressure was also measured. Blood pressure fell in all subjects 5-10 min after injection of the drug cardiac output increased in all patients studied. however, the initial change in cardiac output differed, as it decreased in two subjects and did not change in one. The largest initial increases in cardiac output were seen in the subjects with the highest pulmonary artery end-diastolic pressure. Patients with an initial decrease in cardiac output were those with the least compliant (stiffest) aortas. We consider that the responsiveness of the baroreceptors determines the size of the increase in cardiac output immediately after reduction of blood pressure by diazoxide. Thus in a patient with a stiff aorta, particularly at low cardiac filling pressure, diazoxide might cause a fall in blood pressure to an unacceptable level.

Adult

Embolism in sinoatrial disease.

Among a series of consecutive patients treated with permanent pacemaker between 1965 and 1976, 43 had sinoatrial disease with paroxysmal tachycardia (group A), 30 sinoatrial disease without tachycardia (group B) and 165 atrioventricular block (group C). A retrospective study showed systemic vascular events compatible with embolism in 35%, 7% and 10% in groups A, B and C, respectively. The groups were comparable as regards age, other diseases and duration of pacemaker therapy. Because of the high incidence of embolism in group A, anticoagulant therapy should be evaluated in patients with the brady-tachycardia syndrome.

Adult

Sinoatrial disease in acute myocardial infarction. Long-term prognosis.

Of 32 patients with acute myocardial infarction complicated by sinoatrial disease, 23 survived. All 23 had inferior infarction. During follow-up lasting 4 to 6 years only one patient developed severe chronic sinoatrial disease (sick sinus syndrome) necessitating permanent pacemaker treatment; twelve others died during this time. In 2 of them death was sudden 5 and 6 months after infarction. Atrial pacing studies in 7 of the 11 patients still alive showed no gross abnormalities. A review of 71 patients with chronic sinoatrial disease treated with a permanent pacemaker revealed only 5 with previous documented infarction. The present data suggest that sinus node dysfunction in patients surviving acute infarction is most often only temporary as is atrioventricular block. Occasionally, however, severe chronic sinoatrial disease requiring a permanent pacemaker may develop later, and this course of events is most likely to occur in those patients who had additional complications during the acute infarct.

Adult

MR imaging of apical hypertrophic cardiomyopathy with left ventricular endomyocardial calcification.

A rare case of apical hypertrophic cardiomyopathy with massive left ventricular endomyocardial calcification was studied with MR. The extent of the hypertrophy was clearly demonstrated, enabling accurate estimations of myocardial mass and volumes. Furthermore, an apical calcification was found and its volume estimated. In this case, MR gave the same information that was available by echocardiography, CT, and cardiac catheterization without the disadvantages of these methods.

Calcinosis