Biomedical subjects

P H Kramer

Publications and source records attributed to P H Kramer.

22 records · Page 2Linked to original sources

PubMed1984

Alterations in angina threshold with nifedipine during pacing induced angina.

Changes in coronary haemodynamics and angina threshold were determined during atrial pacing in 11 patients with fixed obstructive coronary artery disease with effort angina before and after the administration of 20 mg of oral nifedipine. Coronary vascular resistance decreased at resting and at "subangina" heart rates but not at "angina" rates. Primary coronary vasodilatation with nifedipine was also suggested by higher coronary sinus oxygen content whether at rest or at subangina or angina heart rates. After nifedipine angina occurred at a lower double product and lower myocardial oxygen consumption. These findings suggest that nifedipine is a coronary vasodilator, but angina can occur at a lower angina threshold in some patients with obstructive coronary artery disease.

Aged↗

PubMed1983

Abnormal diastolic left ventricular posterior wall motion in left ventricular hypertrophy.

The left ventricular pressure-volume relationship is abnormal in left ventricular hypertrophy (LVH). As a result, the left atrium empties more slowly than normal during the rapid filling phase of diastole, producing a characteristic abnormality of diastolic aortic root motion. In order to determine whether this altered LV filling is accompanied by a derangement of diastolic LV wall motion which might be useful in identifying the presence of altered chamber compliance, the M-mode echocardiograms of 60 patients with LVH secondary to aortic stenosis, hypertrophic subaortic stenosis, or hypertension, and those of 36 normal individuals were evaluated. Patients with LVH demonstrated abnormal LV posterior wall motion manifested by prolonged phases of rapid ventricular filling and atrial contraction (p less than 0.01 and p less than 0.05, respectively). The early diastolic wall motion abnormality can be readily detected by visual inspection of the echocardiogram. These findings support the concept of diastolic dysfunction in LVH and represent another echocardiographic feature of that condition.

Adult↗

PubMed1983

Severe aortic insufficiency in juvenile chronic arthritis.

Valvular heart disease is rare in patients with juvenile chronic arthritis. We describe a 27-year-old woman with the systemic-onset form of juvenile chronic arthritis in whom aortic insufficiency necessitated valve replacement. Nodules were seen on both the aortic and anterior mitral leaflets at surgery, and histopathologic evaluation of the excised aortic leaflets demonstrated nonspecific changes similar to those described in rheumatoid valve disease causing aortic insufficiency in adults with rheumatoid arthritis. We believe that this is the first reported case of aortic insufficiency in systemic-onset juvenile chronic arthritis in which the pathologic condition of the valve can be attributed to the underlying disease.

Adult↗

PubMedDate not supplied

Stress echocardiography: technical considerations.

Stress echocardiography has evolved into a widely practiced and accepted method for the noninvasive assessment of the status of the coronary anatomy. Furthermore, this modality incorporates the ability to assess left ventricular function, valvular structure and function, intracardiac masses, the pericardium, and hemodynamics. The extent to which this tool can reliably provide useful clinical information is dependent, in part, on optimal performance. The purpose of this report is to provide an overview of those technical considerations that can contribute to the successful operation of a stress echocardiography laboratory. Consideration is given to personnel qualifications, functional requirements of the digital acquisition/storage/replay system, functional integration of the various hardware components, characteristics of the software, physical layout of the facility, and alternatives to treadmill exercise as the stressor. A thorough understanding of the physiologic basis of stress echocardiography, coupled with optimization of resources used in its performance, enable this tool to be an extraordinarily useful and cost-efficient method for comprehensive cardiovascular assessment.

Contrast Media↗