Background. We examined the clinical and echocardiographic characteristics of patients undergoing aortic valve replacement for aortic stenosis whose continuous wave Doppler studies showed abnormal intracavitary flow acceleration.Methods and Resuls. The clinical and Doppler echocardiographic records of 53 consecutive patients undergoing aortic valve replacement for aortic stenosis were reviewed. Doppler echocardiography was performed at a mean of 6.6 days (range, 0-22 days) after surgery. Thirteen patients (group 1) had a dagger-shaped high-velocity systolic flow signal indicative of abnormal intracavitary flow acceleration on their postoperative Doppler study; group 2 comprised 40 aortic stenosis patients who underwent aortic valve replacement but had no postoperative evidence of abnormal intracavitary flow acceleration. Group 1 postoperative abnormal intracavitary flow velocities ranged from 1.8 to 6.8 m/sec (mean, 4.9±0.9 m/sec): Resulting dynamic gradients ranged from 10 to 184 mm Hg (mean, 104.6±32 mm Hg). Compared with group 2, group 1 patients had a distinctive ventricular geometry with more-pronounced hypertrophy, smaller cavities, and higher ejection fraction. Systolic anterior motion of the mitral valve did not accompany abnormal intracavitary flow acceleration in any patient. Six of 13 group 1 patients suflered postoperative hemodynamic compromise characterized by severe hypotension despite adequate pulmonary capillary wedge pressures; group 1 postoperative mortality was significantly greater than that seen in group 2 patients (38% versus 12%, p<0.05).Conclsions. Abnormal intracavitary flow acceleration after aortic valve replacement for severe aortic stenosis is associated with a distinctive ventricular geometry and supernormal systolic function but not systolic anterior motion of the mitral valve. Such flow acceleration appears to be a marker for increased postoperative morbidity and mortality. Preoperative and postoperative Doppler echocardiography may be useful in risk stratification and guiding therapy. (Circulation 1992;86:926-936)
We studied the effect of cod-liver oil on the development and progression of coronary artery disease in swine subjected to coronary balloon abrasion and fed an atherogenic diet for eight months. Sections from serial 3-mm segments of the coronary arteries were analyzed morphometrically in 7 pigs given a cod-liver-oil supplement and 11 control animals not given the supplement. Significantly less disease was seen in the sections from the animals fed cod-liver oil. The mean lesion area per vessel, mean luminal encroachment per vessel, and mean maximal luminal encroachment per vessel were reduced in animals fed cod-liver oil, as compared with controls, (P = 0.05, P = 0.016, and P = 0.011, respectively). Both groups of animals had severe hyperlipidemia throughout the study. Differences in the extent of coronary atherosclerosis were not related to differences in plasma lipid levels. Platelet arachidonate was markedly reduced, platelet eicosapentaenoic acid was increased, and serum thromboxane was decreased in the oil-fed group as compared with the control group. We conclude that in our animal mode, dietary cod-liver oil retarded the development of coronary artery disease, possibly through changes in prostaglandin metabolism.
Although radiofrequency catheter ablation has undergone explosive growth as the treatment for a variety of arrhythmias, a limiting factor with the existing catheter delivery system has been the relatively small size of the lesions, which appears to be in part due to coagulum formation around the catheter tip, producing a rise in impedance and limiting energy delivery. In order to test the hypothesis that infusion of saline during radiofrequency current application can increase the lesion size and decrease the incidence of impedance rise, ten dogs were each given two radiofrequency ablation lesions to the left ventricular endocardium. One of these lesions was delivered with a standard 7 French quadripolar catheter with a 2-mm tip, and the second was done with a 7 French luminal electrode catheter (also with a 2-mm tip) for the infusion of normal saline during the delivery of radiofrequency energy. Energy was delivered for 60 seconds at either 10 or 20 watts at two distinct sites in the left ventricle for each animal. Four to 7 days following ablation, the animals were sacrificed for pathological examination. The lesions created with the saline infusion catheter were significantly bigger than those produced with a standard catheter (7.3 x 7.0 x 5.1 vs 5.2 x 4.9 x 3.5 mm, respectively, P < 0.001). At the lower energy level (10 W), none of the animals with the saline infusion catheter experienced an impedance rise versus 3 of 5 of the animals in whom the standard catheter was used.(ABSTRACT TRUNCATED AT 250 WORDS)
Synchronized coronary sinus retroperfusion (SCSR) 381-388, 1986. THE CONCEPT OF perfusing the heart via the coronary sinus is based on the observation that the coronary venous system is not affected by the atherosclerotic process . 1 It has been known since the late 1 800s5 that myocardial viability in animals can be maintained through retrograde flow of oxygenated blood via the coronary sinus. In the late 1940s, Beck and his colleagues6',7 demonstrated that shunting of arterialized blood to the coronary venous system could relieve angina in patients with chronic coronary artery disease. The major limitation of surgical retroperfusion was the inadequacy of venous drainage, which led to engorgement of the coronary sinus, myocardial edema, and heart failure. Beck's operation was superceded by direct myocardial revascularization with saphenous vein grafts, a more physiologically appealing
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