Cardiovascular changes in pregnancy evaluated by two-dimensional and Doppler echocardiography.

During pregnancy significant cardiovascular changes occur. To study these anatomic and physiologic changes we performed two-dimensional and Doppler echocardiography in 28 women during the third trimester (34.4 +/- 1.9 weeks) of pregnancy and then again after delivery (7.8 +/- 2.2 weeks). Fourteen nonpregnant age- and sex-matched subjects served as controls. Left ventricular diastolic and systolic dimensions were similar among pregnant, postpartum, and control subjects. Left atrial area as determined by two-dimensional echocardiography was significantly larger during pregnancy (16.7 +/- 4.0 cm2) compared with measurements postpartum (13.8 +/- 3.1 cm2) and with controls (15.5 +/- 3.5 cm2) (p less than 0.01). Doppler study showed that the ratio of early diastolic flow velocity to late diastolic flow velocity (E/A max) and E/A integral were lower among pregnant subjects (1.3 +/- 0.3, 2.0 +/- 0.5) compared with postpartum subjects (1.6 +/- 0.4, 2.5 +/- 1.5) and controls (1.9 +/- 0.5, 3.0 +/- 0.8) (p less than 0.05). Heart rate was higher among pregnant subjects (84 +/- 10 beats/min) compared with postpartum subjects (70 +/- 16) and controls (69 +/- 13) (p less than 0.05). In summary, in pregnant subjects during late third trimester left ventricular chamber dimensions were similar to these postpartum measurements in control subjects; however, the left atrium is dilated during pregnancy. Although there are significant alterations in Doppler-derived left ventricular diastolic parameters during the third trimester, increased heart rate and a dilated left atrium may explain these findings.

Exercise thallium-201 imaging in complete left bundle branch block and the prevalence of septal perfusion defects.

To determine the prevalence of septal defects in a generalized referral population, the records of 93 consecutive patients with complete left bundle branch block (BBB) who underwent symptom-limited treadmill exercise testing with thallium-201 myocardial imaging over a 3-year period were reviewed. Segmental analysis of the planar thallium-201 images was performed in a blinded fashion with agreement by consensus. Computerized quantitative analysis of the images also was independently performed, and was correlated with the visual interpretations. Forty-seven patients (51%) had normal images, and 46 (49%) had defects of greater than or equal to 2 segments. In the abnormal studies, only 13 patients (14% of the total population) had septal defects, while a much higher number of patients, 33 (39%), had inferior or apical defects, or both. Coronary angiography was performed in 6 patients with septal defects: Significant narrowing of the left anterior descending coronary artery was found in 4 patients, a narrowed right coronary artery was found in 1, and normal coronary arteries were seen in the other patient. In conclusion, whereas previous studies have suggested a high percentage of false-positive septal defects in patients with left BBB, this study demonstrates a low prevalence (14%) of septal defects in a large population of unselected patients presenting for exercise thallium-201 imaging. Therefore, exercise thallium-201 imaging remains a useful procedure for evaluating patients with complete left BBB.

Immunostimulation by cryosurgery: an orthotopic model of prostate and bladder cancer in the rat.

In patients with prostate cancer, cryosurgery has been highly effective in eradication of the primary tumor. Certain clinical observations have suggested the presence of an additional systemic anticancer effect, presumably immunologic in nature, but proof is lacking. To study this problem further, we developed two animal tumor models. Instead of using the classical subcutaneous site, we transplanted the 11095A and R-3327 prostate tumors into rat prostate, the 4909 bladder tumor into rat bladder. In these respective orthotopic locations, the 3 tumors displayed favorable growth characteristics with good accessibility for cryosurgery. This model should be considered for studies involving any localized treatment of an established urologic tumor.