Robert A. Phillips

Significance of distal false lumen after type A dissection repair

Fifty-eight patients underwent repair of acute type A dissection between 1986 and 1992. Follow-up aortogram, computed tomographic scan with contrast, magnetic resonance imaging scan, or a combination of these tests was available in 38 patients with preoperatively patent distal false lumens. All distal anastomoses were constructed with the open technique during a period of circulatory arrest. There were 25 suture and 13 intraluminal graft anastomoses. Patency of the distal false lumen was found in 47.3%. Use of the intraluminal graft for the distal anastomosis decreased patency, although not significantly (4/13, 30% versus 14/25, 56%; p = 0.14). The direction of flow into the false lumen was antegrade in 11 of 24 (45.8%) of sutured anastomoses and 0 of 9 intraluminal graft anastomoses (p < 0.01). Actuarial survival at 5 years for patients with closed distal false lumen was 95% +/- 4.8% versus 76% +/- 15% for patients with patency of the distal false lumen (p = not significant). Event-free survival at 5 years for both groups was 84% +/- 8.3% (closed false lumen) and 63% +/- 13.5% (patency of distal false lumen; p = not significant). This experience indicates that in the treatment of acute type A dissections, operative strategy and anastomotic technique play a role in reducing the incidence of patency and related complications of the distal false lumen.

Normalization of left ventricular mass and associated changes in neurohormones and atrial natriuretic peptide after 1 year of sustained nifedipine therapy for severe hypertension

Sixteen patients with severe hypertension were treated for 1 year with extended release nifedipine, during which time serial changes in left ventricular mass index and associated alterations in left ventricular systolic function, left ventricular filling, plasma renin activity, atrial natriuretic peptide and catecholamines were evaluated. Mean seated blood pressure (+/- SE) was significantly reduced from 200 +/- 8/122 +/- 3 to 144 +/- 5/89 +/- 2 mm Hg (p less than 0.0001) at 1 year. After 6 months, left ventricular mass index was significantly reduced by 19% from 121 +/- 8 to 96 +/- 7 g/m2 and this reduction was sustained at 1 year. Septal and posterior wall thickness were reduced from 13.4 +/- 0.1 to 11.2 +/- 0.04 mm and from 12.8 +/- 0.1 to 10.0 +/- 0.03 mm (p less than 0.001), respectively. The prevalence of left ventricular hypertrophy decreased from 63% to 25%. Left ventricular fractional shortening increased from 34 +/- 2% to 41 +/- 3% (p less than 0.05) and the relation between fractional shortening and end-systolic stress did not change. Over the year of sustained blood pressure reduction, the peak velocity of early filling increased from 57 +/- 3 to 63 +/- 4 cm/s (p = 0.07), peak velocity of late filling did not change and the ratio of late to early peak left ventricular filling velocity significantly decreased (p less than 0.05). Plasma atrial natriuretic peptide levels, markedly elevated at entry, decreased from 70 +/- 15 to 41 +/- 8 pg/ml at 1 year (p less than 0.05). Plasma renin activity and catecholamine levels were not altered.(ABSTRACT TRUNCATED AT 250 WORDS)