John D. Stephens

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Twelve patients were studied by rest and exercise radionuclide ventriculography following left ventricular aneurysmectomy (LVA). Left ventricular filling pressure (LVFP) was also measured. Nine patients had been studied pre-LVA at rest and exercise before and after isosorbide dinitrate (ISDN). Resting ejection fraction (LVEF) improved after LVA (p less than(More)
We analyzed 3000 consecutive amniocenteses for prenatal diagnosis to assess the frequency of abnormalities, safety of the procedure, technical and interpretive difficulties and overall diagnostic accuracy. Chromosomal abnormalities were detected in 2.4 per cent of the 2404 pregnancies tested because of advanced maternal age (greater than or equal to 35(More)
Seven patients with severe chronic congestive cardiac failure secondary to ischaemic heart disease performed submaximal supine exercise before and after 5 mg sublingual isosorbide dinitrate at the time of cardiac catheterisation. Exercise before isosorbide dinitrate produced a poor response in left ventricular performance. After isosorbide dinitrate this(More)
The effects on coronary dynamics of propranolol and atenolol were studied in 12 patients undergoing cardiac catheterisation for suspected coronary artery disease. Myocardial blood flow was measured using the coronary sinus continuous thermodilution technique. Data were obtained immediately after drug administration and during rapid atrial pacing. The(More)