Intracardiac impedance monitors hemodynamic deterioration in a chronic heart failure pig model.

INTRODUCTION: A large number of heart failure (HF) patients benefit from cardiac resynchronization therapy. Measurements of intrathoracic impedance (ITZ) by implantable devices correlate with intrathoracic fluid content and are used for monitoring lung edema formation in HF patients. However, intrathoracic fluid is only an indirect parameter of cardiac function. We hypothesized that changes in intracardiac impedance correlate with left ventricular (LV) volume changes. Therefore, measurements of intracardiac impedance between a right ventricular lead and a LV lead may be used to monitor long-term changes of LV function. METHODS AND RESULTS: HF was successfully induced in nine mini-pigs by continuous high-rate pacing. Hemodynamic parameters as well as intracardiac impedance and ITZ were measured before HF induction and after 20 +/- 5 days of high-rate pacing. After the pacing period, we found a significant deterioration of hemodynamics, reflected by a reduction of ejection fraction from 71+/-11% to 48+/-7% and an increase of LV end diastolic pressure (EDP) from 12 +/- 4 mmHg to 26 +/- 8 mmHg. Worsening of cardiac function correlated with a significant >30% decrease of end diastolic intracardiac impedance, in accordance with a >20% increase of end diastolic volume (EDV). ITZ decreased by more than 8%. We observed a significant inverse correlation between end diastolic intracardiac impedance and EDP (r =-0.81, P < 0.001). CONCLUSIONS: In this animal model, changes of intracardiac impedance revealed hemodynamic deterioration as reflected by EDV and EDP pressure. Thus, intracardiac impedance is a promising new application to monitor heart failure status within implantable devices.

Evidence of parthenogenetic origin of ovarian teratoma: case report.

This case report represents one of the few documented cases of parthenote embryo retrieval from an IVF patient with a history of ovarian teratomas. A 29-year-old woman presented at our centre with a history of primary infertility for 6 years due to male factor. She had undergone left oophorectomy 4 years before due to an ovarian teratoma. An ultrasound scan performed during basal evaluation revealed two complex images in the right ovary suggesting teratomas, measuring 2.5 x 2.4 and 1.7 x 1.3 cm. A significant extent of sonographically normal ovarian parenchyma was present, and the patient underwent the long leuprolide acetate protocol of ovarian stimulation with recombinant FSH for an IVF-ICSI cycle. She had 13 metaphase II (MII), four metaphase I (MI), two germinal vesicle (GV) oocytes and one 4-cell embryo retrieved. Eight out of nine injected oocytes were fertilized normally while one was unfertilized. Embryo transfer was carried out 72 h after retrieval. The 4-cell (parthenote) embryo recovered at oocyte retrieval continued to cleave in culture, developing into a 7-cell embryo by the next day. The embryo was morphologically normal, presenting an evident nucleus in each blastomere. Fluorescent in situ hybridization (FISH) returned two signals for the X chromosome in each blastomere that was analysed. Of the eight normally fertilized embryos, three were transferred, resulting in a normal singleton pregnancy and the birth of a healthy baby.