glycogen and Hypertension--Pulmonary

Cardiac septal hypertrophy occurs after in utero ritodrine exposure. To assess the effect of septal hypertrophy on cardiac function we obtained M-mode echocardiograms on day 1 of life in 41 infants exposed to ritodrine and 22 control infants matched for gestational age. Mean duration of ritodrine exposure was 16.2 +/- 13.2 days (range 1 to 49 days). Disproportionate septal hypertrophy (DSH) was defined as an interventricular septal thickness/posterior wall thickness ratio (ST/PW) of greater than 1.3. Infants exposed to ritodrine in utero had DSH and increased right systolic time intervals compared with control values (P less than 0.05). A subgroup, those infants exposed for 2 weeks or longer, had not only DSH but also an absolute increase in septal thickness compared with control infants and infants exposed to ritodrine for less than 2 weeks. ST/PW correlated well with the duration of ritodrine exposure (r = 0.96); the longer the exposure the thicker the septum. Although all echocardiographic changes lasted for less than 3 months, we have no information regarding the effect on the fetus of maternal ritodrine exposure for longer than 7 weeks. Until such information is available, cardiac evaluation is recommended in neonates exposed to ritodrine in utero for longer than 7 weeks.

Topics: Cardiomyopathy, Hypertrophic; Echocardiography; Female; Glycogen; Heart Septum; Humans; Hypertension, Pulmonary; Infant, Newborn; Maternal-Fetal Exchange; Pregnancy; Prenatal Exposure Delayed Effects; Ritodrine; Tachycardia

Intermittent high altitude hypoxia (8 hours a day, 5 days a week, stepwise up to the altitude of 7000 m, total number of exposures 24) induced in male and female rats, chronic pulmonary hypertension and right ventricular hypertrophy. No significant sex differences were found in both these parameters. A significant sex difference was demonstrated in the resistance of the cardiac muscle to acute anoxia in vitro: the myocardium of control female rats proved to be significantly more resistant to oxygen deficiency. Intermittent altitude hypoxia resulted in significantly enhanced resistance in both sexes, yet the sex difference was maintained. Sex differences were further observed in the growth response of experimental animals to the acclimatization process. Whereas the body weight of male rats exposed to intermittent altitude hypoxia was significantly lower, hypoxic females had body weights comparable to those of control animals.

Topics: Altitude; Animals; Body Weight; Cardiomegaly; Female; Glycogen; Hemodynamics; Hemoglobins; Hypertension, Pulmonary; Hypoxia; Male; Myocardial Contraction; Myocardium; Rats; Rats, Inbred Strains; Sex Factors

Glycogen aggregates in the cardiac muscle cell, which have been frequently demonstrated in endomyocardial biopsies under the transmission electron microscope, were studied using the optical microscope in order to clarify their histopathological significance in various heart diseases. The right ventricular muscle biopsies were obtained from the following 120 patients: 24 cases of congestive cardiomyopathy, 26 of hypertrophic cardiomyopathy, 28 of atrial septal defect, 6 of primary pulmonary hypertension, 31 of bradyarrhythmic hearts and 5 controls. The tissue specimens were fixed with glutaraldehyde and osmium tetraoxide, and embedded in epoxy resin. Semi-thin sections from these specimens were dyed with tribasic staining originated by KUROTAKI (1972). Under the optical microscope, glycogen is clearly identified by its forming red stained areas which are seen not only in the subsarcolemmal layers and the perinuclear region, but also in the intermyofibrillar zones. The glycogen aggregates are more frequently observed in the specimens from the atrial septal defects and the bradyarrhythmic hearts than in the other cases. Thus, observation of glycogen aggregates reveals notable differences in appearance depending on the kinds of diseases. In the bradyarrhythmic hearts, the glycogen aggregates can be more readily observed in specimens from younger patients than in elderly ones. Furthermore, the glycogen aggregates appear regardless of both the grades of hypertrophy and degeneration in myocardial cells. These results do not agree with previous reports that the occurrence of glycogen is proportional with the grade of cardiac cell hypertrophy and/or damage.

Topics: Adult; Aged; Bradycardia; Cardiomyopathies; Endocardium; Female; Glycogen; Heart Septal Defects, Atrial; Humans; Hypertension, Pulmonary; Male; Middle Aged; Mitochondria, Heart; Muscles; Myofibrils