Prevention of morphological changes of great arteries in coarctation of the aorta with antihypertensive therapy.

The possibility of preventing morphological changes in arterial walls in coarctation of the thoracic aorta with antihypertensive therapy was evaluated in an experimental study on dogs. Seven mongrel dogs weighing 2350-2980 g were operated upon at the age of 2 months. Antihypertensive therapy with a diuretic (hydrocholothiazide 25 mg/day), beta-blocker (propranolol and 80 mg/day) and vasodilatator (prazosin ad 40 mg/day) was started 1 month after the experimental coarctation was produced in the animals. Blood pressure decreased significantly, although not to the level of the control group. Seven months after the coarctation a perfusion fixation was done. Morphometrical light microscopic analysis was performed on the coronary and cerebral arteries. The histochemical findings in the aorta were analysed qualitatively, as was the amount of lipid in the coronary and the middle cerebral arteries. Electron microscopic studies were performed on the coronary artery. The findings were compared to the control and coarctated (non-treated) groups studied earlier (Uhari et al., 1982). Active antihypertensive therapy prevented all the major morphological changes previously reported to occur in coarctation. We suggest that active antihypertensive therapy started immediately after the diagnosis of coarctation might improve the prognosis of the patients with aortic coarctation by preventing morphological changes in the great arteries.