Developmental changes of cardiac repolarization in rabbits: implications for the role of sex hormones.

Objectives: Firstly, to compare gender-dependent differences of cardiac repolarization in both adult and young rabbits. Secondly, to analyze the effect of gonadectomy on these gender differences in cardiac repolarization.

Methods: We evaluated potential gender differences in cardiac repolarization with both microelectrode and ECG recordings.

Sex differences on the electrocardiographic pattern of cardiac repolarization: possible role of testosterone.

Background: Cardiac repolarization has been shown to be shorter and faster in men compared with women. In this study, we examined the electrocardiographic pattern of repolarization in patients with abnormal plasma levels of testosterone to gain insight into the role that this hormone plays in modulating repolarization.

Methods And Results: Repolarization was measured in 27 castrated men, 26 women with virilization, and 53 control subjects pair-matched for age and sex.

Sex-dependent electrocardiographic pattern of cardiac repolarization.

Background: Although sex-dependent differences in cardiac repolarization have been known for many years, few attempts have been carried out to define the individual contribution of each electrocardiographic (ECG) repolarization variable to the sex-dependent pattern.

Method And Results: We analyzed several ECG repolarization variables that reflect both the duration and the rate of repolarization in 500 normal healthy subjects between the ages of 20 and 80 years (250 men and 250 women) and distributed into 5 groups according to age. Cardiac repolarization, measured in the precordial lead exhibiting the highest T-wave amplitude, was found to be shorter and faster in normal men compared with normal women (P <.

Transseptal left heart catheterization: usefulness of the intracavitary electrocardiogram in the localization of the fossa ovalis.

One of the major difficulties in left heart catheterization through the interatrial septum is to ensure that the Brockenbrough needle tip is correctly laid on the fossa ovalis floor (FOF), which is the only area where the puncture must be done. The difficulties may be enhanced in patients with atrial enlargement and subsequent distortion of the anatomical structures. In order to reduce the hazards of the septal puncture, an electrocardiographic mapping of the right atrial endocardium was performed using the Brockenbrough needle as an exploratory electrode in a group of 20 patients.

Isosorbide-5-mononitrate and isosorbide dinitrate retard in the treatment of coronary heart disease: a multi-centre study.

A multi-centre study was carried out in 200 coronary patients to compare the efficacy and tolerance of isosorbide dinitrate retard (40 mg) and isosorbide-5-mononitrate (20 mg) with regard to the frequency of anginal attacks and consumption of sub-lingual (short acting) nitrates. After receiving treatment for 2 weeks with isosorbide dinitrate retard at a dosage of 2 or 3 tablets per day, only those patients continued the study who had a weekly average of 4 or more anginal attacks during this basal period. The selected patients were divided in 4 groups of 50 patients and received treatment for a further 4 weeks with either isosorbide dinitrate retard at a dosage of 2 tablets (Group D2) or 3 tablets (D3) per day or isosorbide-5-mononitrate at a dosage of 2 tablets (Group M2) or 3 tablets (Group M3) per day.