Cells in part of the septum primum die creating a hole while muscle cells, the "septum secundum", grow along the right atrial side the septum primum, except for one region, leaving a gap through which blood can pass from the right artium to the left atrium, the foramen ovale. A small vessel, the ductus arteriosus allows blood from the pulmonary artery to pass to the aorta. Changes at birth
The ductus arteriosus stays open because of circulating factors including prostaglandins. The foramen ovale stays open because of the flow of blood from the right atrium to the left atrium. As the lungs expand, blood flows easily through the lungs and the membranous portion of the foramen ovale (the septum primum) flops over the muscular portion (the septum secundum). If the closure is incomplete, the result is a patent foramen ovale. The two flaps may fuse, but many adults have a foramen ovale that stays closed only because of the pressure difference between the atria. Theories
Rokitansky (1875) explained congenital heart defects as breaks in heart development at various ontogenesis stages. Spitzer (1923) treats them as returns to one of the phylogenesis stages. Krimski (1963), synthesizing two previous points of view, considered congenital heart diseases as a stop of development at the certain stage of ontogenesis, corresponding to this or that stage of the phylogenesis. Hence these theories can explain feminine and neutral types of defects only. Diagnosis
Many congenital heart defects can be diagnosed prenatally by fetal echocardiography.
An ACE inhibitor and thiazide combination is a drug combination used to treat hypertension (high blood pressure). They are given by mouth. ACE inhibitors reduce the activity of angiotensin-converting enzyme (ACE) which produces angiotensin II, a hormone that constricts blood vessels. Thiazides are a class of diuretics that inhibit the thiazide receptor, thereby increasing urine production and reducing excess water and salt in the body. Several organizations recommend combination therapy for hypertension in cases of failure of a single drug to achieve target blood pressure, or even as a first line treatment for some patients. Examples
Enalapril/hydrochlorothiazide (trade name Enalapril comp), wherein enalapril is the ACE inhibitor and hydrochlorothiazide is the thiazide. Quinapril/hydrochlorothiazide (trade name Accuretic)
Lisinopril/hydrochlorothiazide is marketed as Prinzide, Zestoretic, and many others. Fosinopril/hydrochlorothiazide
Fosinopril/hydrochlorothiazide (trade name Monopril HCT) has a boxed warning about its risk to cause morbidity and mortality in the baby when being used during pregnancy (2nd and 3rd trimesters).FDA  modified its labeling on February, 2009 to include a precaution of drug interaction with gold. "Nitritoid reactions (symptoms include facial flushing, nausea, vomiting and hypotension) have been reported rarely in patients on therapy with injectable gold (sodium aurothiomalate) and concomitant ACE inhibitor therapy including Monopril/Monopril HCT." See also
Perindopril/indapamide, a combination of an ACE inhibitor and a thiazide-like diuretic


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