Role of increases in heart rate in determining the occurrence and frequency of myocardial ischemia during daily life in patients with stable coronary artery disease.

Objectives: The goal of this study was to investigate the role of increases in heart rate in the development of ischemic episodes recorded during ambulatory electrocardiographic (ECG) monitoring in patients with stable coronary artery disease and to establish the importance of such increases in determining the frequency of ambulatory myocardial ischemia.

Background: The factors that determine the occurrence and frequency of episodes of myocardial ischemia that patients with stable coronary artery disease experience during daily life have not been clearly defined. In particular, the role of increases in heart rate in the development of myocardial ischemia is controversial.

Relation between left ventricular function at rest and with exercise and silent myocardial ischemia.

The prognostic value of radionuclide measures of left ventricular function at rest and exercise is well established. Some studies have suggested that the frequency and duration of silent ischemia during ambulatory monitoring provide similar prognostic information; however, studies comparing these two techniques have not been performed. This study examines the relation between left ventricular function at rest and exercise-induced ischemia assessed by radionuclide ventriculography with myocardial ischemia during ambulatory electrocardiographic (ECG) monitoring.

Long-term variation in myocardial ischemia during daily life in patients with stable coronary artery disease: its relation to changes in the ischemic threshold.

Long-term variation in the frequency of myocardial ischemia during daily activity in patients with coronary artery disease who do not experience symptomatic changes has not been documented. Because at one point in time, the magnitude of such ischemia is strongly related to the ischemic threshold measured during exercise testing, this study was undertaken to determine whether patients with stable coronary artery disease show long-term variations in the frequency and duration of myocardial ischemia and to establish whether such variability is related to parallel changes in the ischemic threshold during exercise testing. Forty consecutive patients (mean age 61 +/- 8 years) who showed a stable clinical course over greater than or equal to 12 months were studied with a repeat exercise treadmill test and ambulatory electrocardiographic (ECG) monitoring after withdrawal of antianginal medications.

Prediction of the frequency and duration of ambulatory myocardial ischemia in patients with stable coronary artery disease by determination of the ischemic threshold from exercise testing: importance of the exercise protocol.

The relation between ambulatory myocardial ischemia and the results of exercise testing in patients with ischemic heart disease remains undefined, because of the dissimilar results of previous reports. To further investigate this issue and, in particular, to ascertain the importance of the exercise protocol in determining that relation, 70 patients with stable coronary artery disease underwent 48 h ambulatory electrocardiographic (ECG) monitoring and treadmill exercise tests after withdrawal of medications. Patients exercised using two different protocols with slow (National Institutes of Health [NIH] combined protocol) and brisk (Bruce protocol) work load increments.

Defining the active site of cytochrome P-450: the crystal and molecular structure of an inhibitor, SKF-525A.

The crystal and molecular structure of the cytochrome P-450 inhibitor, SKF-525A [2-(diethylamino)ethyl 2,2-diphenylpentenoate; proadifen hydrochloride] is described. Proadifen hydrochloride crystallized from an ethyl acetate and acetic acid mixture in the space group P2(1)/c with one molecule in the asymmetric unit. Cell constants are a = 18.

Characteristics of borderline personality disorder admissions to private psychiatric hospitals.

Inpatients diagnosed as having borderline personality disorder (BPD) by DSM-III criteria who were admitted to 11 Central Neuropsychiatric Hospital Association (CNPHA) hospitals in 1982 and 1983 are described in terms of 28 clinical-history and demographic characteristics. This study statistically compared 181 BPD inpatients to 1,121 non-BPD inpatients admitted to the same hospitals during the same period as part of the broader CNPHA prospective outcome study. These BPD inpatients were also compared to other BPD samples described in the literature.

The Na:K pump in red cells is electrogenic.

The membrane potential, E, of the red cell measured with a fluorescent dye, 3,3'-dipropylthiadicarbocyanine iodide, hyperpolarizes when the Na:K pump is activated by adding external K and depolarizes upon the subsequent addition of ouabain. The electrogenic pump is optimally observed in cells where internal Na+ has been raised, SO2-(4) has replaced Cl-, and SO2-(4) permeability has been inhibited by 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS)). The change in E associated with the electrogenic component is about 6 mV in human red cells, somewhat smaller in sheep, and larger in duck and Amphiuma red cells.

Anion inhibitor-sensitive unidirectional sodium movements in the human erythrocyte.

The increased unidirectional sodium influx found when human erythrocytes are suspended in isotonic salt solutions containing bicarbonate ions as a replacement for chloride ions was examined. The increased sodium movement appears to have the transport characteristics of anion movement. Inhibitors of anion transport such as furosemide, fluorodinitrobenzene (FDNB), and 4-acetamido-4'-isothiocyano-stilbene-2-2'-disulfonic acid (SITS) drastically inhibit these augmented sodium movements.

Thrombosis at the site of interruption of the vena cava: a consideration in prophylactic treatment of pulmonary embolism.

This study confirms the method of Ratnoff in inducing the hypercoagulable state in dogs, and further demonstrates that there is a varying thrombogenic factor when the vena cava is interrupted by ligation, staple plication, suture plication, serrated clip, and a smooth clip. The incidence of thrombosis caused by ligation, staple plication and suture plication would suggest that these are not suitable methods for prophylactic use. That no thrombosis occurred with the smooth clip would suggest that as a prophylactic measure, the smooth clip may be preferable to a serrated clip.