Magnesium transport across the basolateral plasma membrane of the fish enterocyte

The aim of the study was to assess the influence of aortic valve replacement on left ventricular size and muscle hypertrophy according to the type of preexisting valve disease (aortic stenosis, insufficiency or combined disease). The study group consisted of 143 consecutive patients (pts) after aortic valve replacement (109 men, 34 women, mean age 48.1 +/- 10.9 years). Reason for the operation was aortic stenosis in 35 pts, aortic insufficiency in 64 pts and combined disease in 44 pts. Echocardiography was performed before surgery, 1 month and 1 year after operation, and yearly during 5-year follow-up. Transvalvular aortic pressure gradients decreased significantly after valve replacement in all subsets without further changes during follow-up (Pmax (mmHg): from 54.2 +/- 20.7 to 17.9 +/- 9.6 in combined disease pts, from 72.3 +/- 19.9 to 21.6 +/- 14.6 in aortic stenosis and from 34.5 +/- 24.2 to 15.6 +/- 11.3 in aortic insufficiency pts, respectively, P < 0.0005). One year after surgery the diastolic dimension of the left ventricle decreased significantly in all subjects, whereas the systolic dimension only in aortic insufficiency and combined disease pts (from 44 +/- 11.8 to 31.6 +/- 5.4 mm, P < 0.001 and from 41.9 +/- 11.5 to 33 +/- 6.7 mm, P < 0.05, respectively). Further decrease of both diastolic and systolic dimensions was observed only in the aortic insufficiency group. Ejection fraction of left ventricle increased only in combined disease pts (from 51.6 +/- 10% to 56.8 +/- 8.2%, P < 0.05). Wall thickness of the left ventricle decreased 1 year after valve replacement only in the aortic stenosis group and in further follow-up in the aortic stenosis and combined disease group. Normalization of left ventricular size is observed in more than 90% of patients during 5-year follow-up as opposed to left ventricular muscle hypertrophy, regressed only in less than a half of the study population. In patients with aortic valve disease the greatest hemodynamic improvement is observed 1 year after valve replacement. This is expressed by marked reduction of the left ventricular dimensions and wall thickness, without significant improvement of the ejection fraction. Further regression of left ventricle dimensions occurs in patients operated on due to predominant valve insufficiency, whereas regression of left ventricular hypertrophy is observed in patients with preexisting valvular stenosis.     

Reduced epicardial coronary vasodilator capacity in patients with left ventricular hypertrophy

BACKGROUND: Enlargement of the epicardial coronary arteries occurs in left ventricular (LV) hypertrophy as an adaptation to the increased coronary blood flow. METHODS AND RESULTS: Vasodilator capacity of the epicardial coronary arteries was determined in 44 patients. The dose-response relation of intracoronary nitroglycerin was assessed in 14 patients (7 control subjects and 7 patients with aortic stenosis [study A]) using quantitative coronary angiography. In a second study (B), vasodilator capacity of the epicardial coronary arteries was determined in 15 control subjects and 15 patients with valvular heart disease. In study A, a curvilinear dose-response relation with maximal vasodilation after 90 micrograms intracoronary nitroglycerin was found in both control subjects and patients with aortic stenosis. Vasodilator capacity was reduced in those with aortic stenosis, although sensitivity to nitroglycerin was similar in both groups. In study B, coronary circumferential length at baseline was larger in those with LV hypertrophy (12.2 +/- 2.2 mm) than in control subjects (8.6 +/- 1.5 mm; P < .001); after 100 micrograms intracoronary nitroglycerin, it increased to 12.9 +/- 2.2 mm (6 +/- 5%) in those with LV hypertrophy and to 10.3 +/- 1.5 mm (21 +/- 8%; P < .001) in control subjects. An inverse relation between baseline circumferential length and its percent increase after nitroglycerin was found (r = -.71, P < .001). CONCLUSIONS: Vasodilator capacity of the epicardial coronary arteries is reduced in patients with LV hypertrophy, although sensitivity to nitroglycerin is normal. This may be due to a flow-mediated decrease in coronary vasomotor tone and/or the occurrence of vascular remodeling with an enlargement of the coronary arteries.     

Surgical treatment of aortic rupture by blunt chest trauma

During a ten-year period, seven patients with traumatic rupture of the thoracic aorta were operated upon. Four patients of them were operated within one week. Chest X-rays and chest computed tomography could not always reveal the exact diagnosis of aortic rupture. Intravenous digital subtraction angiography was useful to confirm the diagnosis. The repair of the rupture was accomplished with the adjunct of left heart bypass using Bio-pump, which was useful to reduce the bloodloss with a limited systemic heparinization. Another three patients were diagnosed to have chronic post-traumatic aneurysm of the thoracic aorta and underwent aortic replacement with prosthetic graft. One of seven patients died at seventh postoperative day because of cerebral contusion, the associated lesion of an automobile accident. It is stated that the aortic rupture is immediately fatal in approximately 80% of individuals, and most of remaining 20% die within 2 weeks unless the lesion is repaired. Therefore immediate operative intervention is recommended when the aortic rupture is strongly suspected. Chronic post-traumatic aneurysms should be resected because it has become apparent that the majority of patients with this lesion will develop complication, such as sudden rupture.     

Infrarenal aortic dimensions in siblings of patients with infrarenal abdominal aortic aneurysm or aortoiliac occlusive disease

OBJECTIVE: To compare the dimensions of the infrarenal aorta and the prevalence of undiagnosed infrarenal abdominal aortic aneurysms in the siblings of patients operated on for either infrarenal abdominal aortic aneurysm or aortoiliac occlusive disease. DESIGN: Prospective screening study. SETTING: University hospital, Finland. SUBJECTS: 220 siblings of patients operated for either abdominal aortic aneurysm or aortoiliac occlusive disease. INTERVENTIONS: Abdominal aortic ultrasound. MAIN OUTCOME MEASURES: Anteroposterior and transversal diameters of infrarenal and suprarenal aorta. RESULTS: There was a group of 5 siblings (4 men and 1 woman, aged 59 years or more) among the aneurysm patients who had a disposition to infrarenal aneurysm formation defined as a dilatation of 30 mm or more. This contrasted with none among the siblings of the patients with aortoiliac occlusive disease (p = 0.07, 95% confidence interval 0.49 to 165.3). The two factors affecting the diameter of the infrarenal aorta were age and sex. The aortic dimensions tended to be bigger in the siblings of the aneurysm patients but the differences were not significant. The ratio of infrarenal to suprarenal diameter was bigger in the siblings of the aneurysm patients also after excluding the cases with detected dilatations (p = 0.05) and in the multivariate analysis the only factor explaining this difference was the type of the disease of the proband. CONCLUSIONS: The screening of male siblings (over 55 years old) of patients with infrarenal abdominal aortic aneurysms might be justified.     

Sinus of Valsalva aneurysms: 20 years' experience

BACKGROUND: Aneurysms of sinus of Valsalva are rare. Here, we analyze retrospectively patients operated on at our center during the last 20 years. PATIENTS AND METHODS: One hundred four cases of congential aneurysm of sinus of Valsalva were operated upon between January 1977 and April 1996. Only 12 aneurysms were unruptured. The majority (76.9%) arose from the right coronary sinus. The right ventricle was the most common chamber of rupture (58.6%). Ventricular septal defect was associated in 46 patients (44.2%), of which 28 (60.9%) were supracristal. Ventricular septal defect was more common in aneurysms arising from the right coronary sinus (91.3%). Aortic incompetence was found in 45 patients (43.3%). The defect was closed through the aortic root alone in 24 patients (23.1%) and through both the aortic root and the chamber of rupture in the remaining 80 patients. Six patients underwent aortic valve repair, and 21 an aortic valve replacement. RESULTS: There were two hospital deaths (1.92%). Morbidities were few. Follow-up ranged from 1 to 20 years (mean 8.2 +/- 1.1). There was one late noncardiac death, and in the majority, the long-term follow-up was uneventful. CONCLUSION: Surgery for aneurysm of sinus of Valsalva yields gratifying results, and it should be undertaken as soon as the condition is diagnosed.     

Regression of left ventricular hypertrophy after aortic valve replacement for aortic stenosis with different valve substitutes

OBJECTIVE: Stentless biologic aortic valves are less obstructive than stented biologic or mechanical valves. Their superior hemodynamic performances are expected to reflect in better regression of left ventricular hypertrophy. We compared the regression of left ventricular hypertrophy in 3 groups of patients undergoing aortic valve replacement for severe aortic stenosis. Group I (10 patients) received stentless biologic aortic valves, group II (10 patients) received stented biologic aortic valves, and group III (10 patients) received bileaflet mechanical aortic valves. METHODS: Echocardiographic evaluations were performed before the operation and after 1 year, and the results were compared with those of a control group. Left ventricular diameters and function, left ventricular wall thickness, and left ventricular mass were assessed by echocardiography. RESULTS: Group I patients had a significantly lower maximum and mean transprosthetic gradient than the other valve groups (P = .001). One year after operation there was a significant reduction in left ventricular mass for all patient groups (P < .01), but mass did not reach normal values (P = .05). Although the rate of regression in the interventricular septum and posterior wall thickness differed slightly among groups, their values at follow-up were comparable and still higher than control values (P = .002). The ratio between interventricular septum and posterior wall and the ratio between wall thickness and chamber radius did not change significantly at follow-up. CONCLUSIONS: Because the number of patients was relatively small, we could not use left ventricular mass regression after I year to distinguish among patients undergoing aortic valve replacement for aortic stenosis by means of valve prostheses with different hemodynamic performances.     

Appearance of the interventricular septum in obstructive lesions of the left ventricular outflow tract

Measurements of the thickness of the septum were made in 26 cardiac specimens and in 13 patients. There were 10 normal specimens, five with aortic stenosis, two with asymmetric septal hypertrophy, four with hypertensive cardiovascular disease, and five with idiopathic cardiomyopathy. Patient measurements were obtained by visualizing the septum during simultaneous left and right ventriculography on angiograms obtained in the left anterior oblique projection. Four patients were normal, five had aortic stenosis, and four had a symmetric septal hypertrophy. Measurements derived from normal cardiac specimens and angiographic appearance suggested that the normal septum is a smooth-walled structure with right and left ventricular surfaces parallel, diverging only slightly at the apex of the ventricle. In aortic stenosis and idiopathic cardiomyopathy, the septum tends to be biconvex with maximal thickening in its middle third. Hypertensive cardiovascular disease produces uniform septal thickening, resembling an exaggeration of normal. However, in asymmetric septal hypertrophy no consistent patterns of hypertrophy or septal thickening are evident; bulging can be present at any point along the left ventricular surface of the septum.     

An evaluation of nasal patency with acoustic rhinometry--preop. and postop. comparisons

PURPOSE: This prospective study was designed to assess the effect of primary hyperparathyroidism on heart muscle, valves, and myocardial function. Echocardiography was used to evaluate changes in mechanical performance, the thickness of the left ventricular wall, myocardial calcific deposits, and valvular calcifications in patients with primary hyperparathyroidism. METHODS: Echocardiography was performed in 54 patients with hyperparathyroidism prior to surgery and 12 +/- 2 months after successful parathyroidectomy. A matched control group was followed for comparison. RESULTS: In a blinded fashion, aortic and mitral valve calcifications were detected in 63% and 49% of patients with primary hyperparathyroidism (controls: 12% and 15%, respectively). Calcific deposits in the myocardium were found in 69% of patients with hyperparathyroidism and 17% of the control subjects. After parathyroidectomy and 12 months of normocalcemia, a significant regression of left ventricular hypertrophy (p < 0.001) was observed. CONCLUSIONS: The present data show a high incidence of left ventricular hypertrophy, calcific deposits in the myocardium, and/or aortic and mitral valve calcification in patients with primary hyperparathyroidism. A 1-year follow-up after parathyroidectomy (and restoration of normocalcemia) discloses regression of hypertrophy, while calcifications persist without evidence of progression.     

Exposure to environmental and mainstream tobacco smoke and risk of spontaneous abortion

The present nationwide, multicenter clinical study was carried out in 26 departments of surgery to define the incidence and attendant mortality of intestinal infarction following abdominal aortic surgery, and to identify patients at risk of it. The data consist of 1752 patients who underwent abdominal aortic reconstruction during 1991-1993 as recorded in the Finnish national vascular registry (FINNVASC). Among the 1752 operations, 27 patients treated at 14 different hospitals had intestinal ischemia, and the complete patient records of all 27 cases were reanalyzed. The incidence of bowel infarction was 1.2%. Among patients operated on for a ruptured aneurysm it was 3.1%, whereas 1.0% of patients with nonruptured aneurysm and 0.6% of those operated on for aortoiliac occlusive disease developed intestinal infarction. In 14 patients (67%) the lesion affected the left colon. The overall 30-day mortality rate was 13% but reached 67% among those with intestinal infarction. We conclude that acute intestinal ischemia with bowel infarction is an infrequent but serious complication of abdominal aortic surgery. It is mainly related to surgery due to aneurysmal disease, and patients with occlusive aortoiliac disease present ischemic complications in the intestines less often. Hypotensive patients being treated for ruptured aneurysm are at greatest risk of intestinal ischemia.     

Open distal anastomosis or aortic balloon occlusion technique during complete aortic arch replacement

The technique of open distal anastomosis or application of aortic balloon occlusion catheter designed to occlude the descending thoracic aorta have been used in 33 and 19 patients, respectively, to control bleeding during the procedure of distal anastomosis for complete aortic arch replacement with a prosthetic graft. These two techniques allowed us a simple approach to the lesion and the avoidance of clamp injury to the fragile aortic tissue. Open distal anastomosis was applied for 91% patients of operated aortic dissection and all emergent cases, it's duration ranged from 10 to 110 minutes with an average of 58 minutes under 18.2 degrees C of lowest esophageal temperature. On the other hand, aortic occlusion balloon was inserted for mainly true aortic aneurysm patients without an emergency, and helped to maintain the perfusion pressure on a lower part of body around 50 mmHg by the 1550 ml/min in an average of perfusion flow femoral artery under 21.2 degrees C of temperature. The difference of postoperative renal and liver function evaluated by serum enzyme levels of total bilirubin, GOT, GPT, LDH, creatinine and BUN did not reach to statistical significance between the patients using open distal anastomosis and balloon occlusion, however, the incidence of postoperative complication including either renal, liver dysfunction, abdominal problem or paraplegia was significantly higher in the patient group with open distal technique. Either open distal anastomosis or aortic balloon occlusion technique would be appropriately selected according to the patient's characteristics or the condition of aortic disease to be operated.     

Operation for chronic traumatic aortic aneurysm: when and how?

BACKGROUND: There are few guidelines for surgical intervention late after unoperated traumatic aortic rupture. We reviewed our experience and the literature to determine when and how to operate. METHODS: Between 1987 and 1997, we treated 9 patients aged 22 to 82 years with chronic traumatic aneurysm. Seven patients underwent aneurysm resection. Two patients have not been operated on. The injury-to-operation interval ranged from 8 weeks to 18 years (mean, 4.1 years). One patient underwent median sternotomy and patch repair during hypothermic circulatory arrest. Six patients underwent left thoracotomy: 2 were operated on with left atrio-femoral bypass, and 4 with hypothermic circulatory arrest and ascending aortic cannulation. RESULTS: There was no surgical mortality or morbidity. The 2 patients who were not operated on remained asymptomatic without radiologic change in the aneurysm after follow-up of 2 and 9 years. CONCLUSIONS: From this limited experience and literature review, we make the following subjective observations: (1) all patients with new symptoms should be operated on promptly, and (2) asymptomatic densely calcified aneurysms detected more than 2 years after the accident can be observed by repeated tomography unless new symptoms arise.     

Risk factors for neonatal thrombocytopenia in pregnancy complicated by idiopathic thrombocytopenic purpura

The Authors report three cases of patients operated for acute thrombotic aortic occlusion. All the three patients were treated with an aortic transabdominal approach, thromboendarteriectomy and aorto-femoral by-pass. In two patients the result was satisfying, one with a late and partial recovery of the motility of the inferior limbs. One patient died for heart failure in eighth postoperative day. The Authors believe that this unsatisfying result was caused by delay in the surgical treatment (almost 30 hours).     

Suppression of protein degradation in progressive cardiac hypertrophy of chronic aortic regurgitation

BACKGROUND: The heart adapts to the volume overload of aortic regurgitation with dilation and hypertrophy. The development of left ventricular hypertrophy at the protein level is a dynamic process resulting from an imbalance between cardiac protein synthesis and degradation. The objective of the present study was to determine in vivo the relative contributions of cardiac protein synthesis and degradation to the progressive hypertrophy that occurs in response to chronic aortic regurgitation and to compare these with responses earlier in the course of this stress. METHODS AND RESULTS: Continuous intravenous infusions of [3H]-leucine were administered 3 days and 1 month after surgical induction of aortic regurgitation and sham operation in rabbits. Total cardiac protein and myosin heavy chain fractional synthesis rates were obtained by analysis of plasma and protein hydrolysate data using [14C]-dansyl chloride assays. Left ventricular growth rates were determined from serial echocardiographic and postmortem left ventricular weight and protein concentration measurements; protein degradation rates were determined by subtraction of growth rates from synthesis rates. CONCLUSIONS: In comparison with sham-operated control rabbits, protein fractional synthesis rates were increased at 3 days but not at 1 month after induction of aortic regurgitation Progressive cardiac hypertrophy occurring at 1 month was caused by a decrease in protein fractional degradation rates. An increase in protein synthesis contributes only to the early phase of hypertrophy caused by acute aortic regurgitation, whereas progressive eccentric hypertrophy in chronic volume overload is due to suppression of protein degradation.     

Superior recovery of hypertrophied rat myocardium after cardioplegic arrest

BACKGROUND: Although cardioplegic protection of the hypertrophied heart remains a clinical challenge, we have previously observed enhanced recovery in rat hearts with pressure-overload hypertrophy induced by aortic banding. We investigated whether this unexpected result is found in other models of hypertrophy. METHODS: Hearts with hypertrophy induced by aortic banding or administration of desoxycorticosterone acetate were each compared with age-matched sham-operated and nonoperated controls. Spontaneously hypertensive rats and Wistar-Kyoto controls were also compared. We evaluated left ventricular isomyosin distribution by gel electrophoresis and recovery of isolated working rat hearts arrested at 8 degrees C for 2 hours. RESULTS: The percentage of V3 isomyosin in hearts with hypertrophy from aortic banding or administration of desoxycorticosterone acetate was increased compared with the control groups. Recovery of aortic flow in all three groups of hypertrophied hearts was at least as good or better than their respective controls. There were no significant differences in ATP or glycogen between hypertrophied and control hearts before or after arrest. CONCLUSIONS: Enhanced recovery of hypertrophied hearts is not specific to a single model. This level of recovery may be supported by induction of a "fetal genetic program," exemplified in the rat by the shift in isomyosin from predominantly V1 to the more efficient V3 isoform, which occurs in pressure-overloaded hearts.     

Late results of a valve-preserving operation in patients with aneurysms of the ascending aorta and root

OBJECTIVES: There is still no agreement about the best method of dealing with malfunction of the aortic valve caused by aneurysm or dissection of the aortic root. The experience, rationale, and development of a valve-preserving technique introduced and used since 1979 is described. METHODS: During this period 158 patients (78% of all patients undergoing resection of aneurysm of the ascending aorta) were operated on using this technique. Their ages ranged from 2 to 72 years (mean 46.6 years). Of the patients 107 were male and 51 were female. A total of 68 patients had skeletal manifestations of Marfan's syndrome. The original disease was chronic aneurysm of the ascending aorta or root in 92 (58.2%), chronic dissection in 17 (10.8%), and acute dissection in 49 (31%) patients. One hundred eleven additional procedures were performed in 84 patients. In all there were five early deaths (4.6% +/- 2%) in the 109 patients with chronic aneurysm and one death in the 103 patients operated on electively (0.97% +/- 0.9%). Actuarial survival for patients operated on for chronic aneurysm was 93.3%, 88.0%, 79.0%, and 57.9% at 1, 5, 10, and 15 years and 96.8%, 91.2%, 82.0%, and 60.0% for those operated on electively. Actuarial survival for patients operated on for acute dissection was 72.8%, 63.4%, and 53.3% at 1, 5, and 10 years. The probability of needing reoperation was 3.0% +/- 2%, 11% +/- 0.5%, and 11% +/- 0.5% at 1, 5, and 10 years. There were no instances of infective endocarditis or thromboembolic complications except in two patients operated on early in the series who had cusp extension. No anticoagulants were used. Echocardiography showed reduction in left ventricular end-systolic and end-diastolic dimensions, which was maintained. At the end of follow-up trivial or no aortic regurgitation was demonstrated in 63.6%, mild to moderate in 33.3%, and severe in 3%. CONCLUSIONS: Valve-sparing operations are possible in a large proportion of patients with aneurysms of the ascending aorta and the medium and long-term results are encouraging.     

Treatment of the aortic valve and ascending aorta. The significance of reconstructive methods on the aortic root

BACKGROUND AND OBJECTIVE: The standard surgical repair of disease of the aortic valve and the ascending aorta has been combined replacement, which includes the disadvantage of inserting a mechanical valve. We have investigated an individualized approach which preserves the native valve. PATIENTS AND METHODS: Between October 1995 and October 1997, a consecutive total of 101 patients (72 men, 29 women, aged 21-83 years) underwent operations for disease of the ascending aorta: aortic dissection type A in 34 patients, aneurysmal dilatation in 67. Dilatation of the aortic arch was associated with aortic regurgitation in 58 patients. There were 11 patients with aortic valve stenosis or previously implanted aortic valve prosthesis among a total of 46 whose aortic valve was replaced (group II). Supracommissural aortic replacement with a Dacron tube was performed in 16 patients (group I) with normal valve cusps and an aortic root diameter < 3.5 cm. In 28 patients with an aortic root diameter of 3.5-5.0 cm the aortic root was remodelled (group III). Resuspension of the native aortic valve was undertaken in 11 patients with aortic root dilatation of > 5.0 cm (group IV). RESULTS: Operative intervention was electively performed in 72 patients, without any death. Of 29 patients operated as an emergency for acute type A dissection four died (14%). In 55 of the 58 patients with aortic regurgitation in proved possible to preserve native aortic valve (95%). In the early postoperative phase and after an average follow-up time of 11.8 months, transthoracic echocardiography demonstrated good aortic valve function, except in one patient each of groups III and IV who developed aortic regurgitation grades I or II. CONCLUSION: The described individualized approach makes it possible to preserve the native aortic valve in most patients with aortic regurgitation, at a low risk. Follow-up observations so far indicate good results of the reconstruction.     

Vascular and neuroendocrine components in altered blood pressure regulation after surgical repair of coarctation of the aorta

STUDY OBJECTIVE: To investigate potential vascular and neuroendocrine determinants of altered blood pressure (BP) regulation in patients previously operated on for aortic coarctation. DESIGN, SETTING AND PATIENTS: We prospectively re-evaluated 45 patients operated on for aortic coarctation at Strasbourg University Hospital over a 13-year period. Four of these patients were less than 2 years old at the time of the operation and four were older than 20 years. Patient age and time since the operation were on average 21+/-13 years and 8+/-3 years, respectively. Surgery consisted of a resection with end-to-end anastomosis for 18 patients, angioplasty (8), prosthesis (4) or sub-clavian flap (15). RESULTS: Despite repair of the coarctation, about 40% of the patients showed an abnormal BP status at rest. The majority of these patients had uncomplicated borderline hypertension. The orthostasis test as well as the BP circadian rhythm were frequently abnormal. While the ankle/arm systolic pressure index measured at rest was generally within the normal range, diminished carotid-femoral pulse wave velocity was observed. Plasma adrenaline and aldosterone levels were elevated in about 50% of the patients examined. CONCLUSIONS: These new findings suggest that there are 'cause and effect' relationships between aortic structural and functional vascular abnormalities, and augmented plasma adrenaline and aldosterone in some patients after coarctation repair. These phenomena are likely to be involved in altered BP regulation and might result in recurrent hypertension.     

Evaluation of the severity of aortic stenosis using 2-dimensional Doppler echocardiography

Hemodynamic evaluation of aortic ostial stenosis (AOS) was made in 89 patients at Doppler echocardiography. Maximal circulation rate (MCR) through the aortic valve averaged 3.47 +/- 0.073 m/s, maximal transaortic pressure gradient (TPG) made up 49.97 +/- 2.11 mm Hg, the aortic ostium area (AOA) amounted to 0.85 +/- 0.031 sm2. It was established that AOA evaluation is most reasonable, as MCR and TPG vary with cardiac output. Especially desirable this measurement is believed in patients with TPG under 64 mm Hg and small left ventricular ejection. Mitral regurgitation is a frequent finding in AOS patients. Unless calcinosis of the mitral ring, mitral valve affection would be absent. In mitral regurgitation the disease took a more severe course, the patients having reduced AOA and left ventricular ejection, though larger end-diastolic diameter and end-diastolic volume. The emergence of mitral regurgitation in AOS is a result of left ventricular hypertrophy and dilatation suggesting a low compensatory reserve of the myocardium.     

Surgical experience in patients with Marfan's syndrome and cardiovascular disease

10 patients with Marfan's syndrome and cardiovascular disease were operated at Tohoku University Hospital from 1971 to 1988. Surgery included composite valve graft replacement of ascending aortic aneurysm with aortic regurgitation in 5 patients and prosthetic mitral valve replacement in three patients; two had resection of aneurysm with Dacron tube replacement. Operative mortality was 10%. Two late death occurred (22%). It was suggested that regular follow-up examination is important in these patients to detect new lesions and to evaluate known lesion.     

Effects of m-Nif and Nif on left ventricle hypertrophy in rats induced by partial ligation of abdominal aorta

Partial ligation of the abdominal aorta of rats was adopted to induce left ventricle hypertrophy (LVH). The effects of m-nifedipine (m-Nif) and nifedipine (Nif) on prevention of hypertrophy and the possible mechanism were investigated. The wet weights of the left ventricle (WWLV) of the LVH group were increased compared with those of the sham operated group. After treatment with m-Nif and Nif for 4 wks, the WWLV decreased by 25% +/- 9% and 16% +/- 9%, respectively. The pressure-volume (P-V) curve of the hypertrophied group was markedly elevated, which means that the myocardial compliance was decreased, and the stiffness coefficient of the hypertrophied group was significantly elevated than that of the sham operated group, but the groups treated with m-Nif or Nif were significantly improved. The characteristics of the left ventricular myocardial DHP binding sites were studied. The results showed that the Kd and the Bmax were similar in the m-Nif, Nif and hypertrophied groups, but the total number of the DHP receptors (TNR) of the LVH group was markly increased than that of the sham operated group, but the TNR of the m-Nif and Nif groups were the same as that of the sham operated group. These results suggest that the effects of m-Nif and Nif on preventing cardiac hypertrophy and improving myocardial compliance may be related to their depressing the TNR of DHP.