RESUMO
BACKGROUND: Analysis of right ventricular adaptation to tricuspid regurgitation was studied in 10 heart transplant recipients following inadvertent endomyocardial biopsy disruption of the tricuspid apparatus. METHODS AND RESULTS: Echocardiography demonstrated progressive diastolic right ventricular cavity enlargement (19.5+/-5.0 to 30.3+/-5.4 cm(2), P<0.0002), with disproportionate elongation along the midminor axis (3.5+/-0.6 to 5. 0+/-0.5 cm, P<0.001). As the right ventricle remodeled to more spherical (and less elliptical) proportions, the end-diastolic right ventricular midminor axis/long axis ratio increased significantly from 0.52+/-0.10 to 0.68+/-0.07, P<0.005. CONCLUSIONS: Ventricular enlargement due to right ventricular volume overload results in disproportionate dilation along the free wall to septum minor axis.
Assuntos
Hipertrofia Ventricular Direita/etiologia , Insuficiência da Valva Tricúspide/complicações , Adulto , Ecocardiografia , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Hipertrofia Ventricular Direita/diagnóstico por imagem , Hipertrofia Ventricular Direita/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sístole , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/fisiopatologiaRESUMO
The management of anticoagulant therapy for the prevention of thromboembolism from prosthetic heart valves in the pregnant patient is far from ideal and deserves more clinical research. Warfarin therapy given alone throughout pregnancy poses high risks to the fetus because it crosses the placental barrier. Heparin alone throughout pregnancy poses high risks to the mother, which might be lessened somewhat by more intensive therapeutic regimens and careful monitoring of the heparin level or anticoagulated state of the blood. Because of the major risk of embryopathy in the fetus during the first trimester and latter half of the third trimester, heparin therapy during those times has been recommended. In the opinion of some experts, high-risk cases may benefit from low-dose aspirin in addition to anticoagulant therapy. The fact that warfarin is contraindicated during pregnancy (according to the pharmaceutical company that markets it) poses some problems for the physician who prescribes it. For the above reason, alternative drugs are worthy of consideration and should be given clinical trials. Low molecular weight heparin has the potential for greatly reducing drug-related risk for the fetus while providing greater safety for the mother.