Coarctation of the aorta: review of 362 operated patients. Long-term follow-up and assessment of prognostic variables

362 patients operated upon for coarctation of the aorta from 1961-1980 were analyzed retrospectively. Age at operation was <2 years in 74 (group A ) and ≧2 years in 288 patients (group B). Associated cardiovascular malformations were common, especially in group A patients. Early mortality was 12-2% for group A and 1-4% for group B patients. 336 patients were followed for 6 months to 21 years (mean 8.9 years). Late mortality was 0.8% per patient year. Associated cardiac defects and postoperative hypertension were responsible for most of the late deaths. Late reoperations were performed because of aortic valve disease, residual coarctation (with persistent hypertension) and aortic aneurysms at the site of anastomosis. The incidence of hypertension decreased from 82.5% preoperatively to 33.5% at discharge from the hospital. It decreased further during follow-up in patients operated <10 years of age, but remained constant in the older patients. In conclusion, morbidity and mortality after operative repair of coarctation are determined mainly by (1) associated cardiac malformations, and (2) postoperative hypertension. Patients with isolated coarctation and postoperative normal blood pressure have an excellent prognosis. Patients operated upon from between 2-9 years of age carry the lowest risk for residual coarctation and late postoperative hypertensio

Isolated aortic valve replacement with the Björk-Shiley tilting disc prosthesis and the porcine bioprosthesis

Between 1977 and 1978, 239 patients underwent aortic valve replacement with either a bioprosthesis (100, BIO) or a Björk-Shiley tilling disc prosthesis (139, BS). Early mortality was 2%, late mortality 4%. There was no statistically significant difference between the two groups. Anticoagulation was maintained indefinitively in patients with a BS, after implantation of a BIO only for three months except in the presence of atrial fibrillation or a history ofeinboli. Thromboembolic complications and anticoagulant hemorrhages were almost twice as frequent in patients with BS than with BIO (5.3 versus 2.8 episodes/100 patient years). This difference however is statistically not significant. There were an equal number (two) of reoperations because of paravalvular leaks due to endocarditis or torn sutures in the two groups. A regurgitant murmur, though hemodynamically not significant, occurred more frequently in patients with BIO than with BS (10% versus 2%, P < 0.05). Its cause and importance cannot yet be determined. Postoperative results judged by the NYHA classification and reduction of heart size were similar in both groups. Of all patients, 13% with preoperative valvular incompetence and 15% with stenosis showed little or no reduction of the cardiothoracic ratio on X-ray indicating a worse long-term prognosis. The porcine BIO has become our preferred valvular substitute because of its low thromboembolic complication rate. The BS is mainly reserved for patients already on anticoagulants for other reaso

Myocardial function and structure in aortic valve disease before and after surgery

Left ventricular (LV) micromanometry, cine-angiography and endomyocardial biopsies were performed in 13 patients with aortic valve disease {AVD) before and 12 to 28 months after successful valve replacement. (AVR). Patients with coronary artery disease were excluded. In nine patients (Group I: five AS, four AI) postoperative LV ejection fraction (EF) and total pressure Vmax were normal(EF ≥ 0.61; Vmax ≥ 1.50 ML/s). In four patients (Group II: three AS, one AT) postoperative EF (0.41) and Vmax (1.21 ML/s) were depressed. Pre-operative muscle fiber diameter (MFD; normal < 20 n) was 31 μ in Group I and 38 μ in Group II (P < 0.01). After AVR MFD decreased to 27 μ in Group I (P < 0.005) and to 28 μ in Group II (P < 0.02). Prior to surgery EF and Vmax showed no significant correlation with the LV fibrous content (FC in g/m2; FC = interstitial fibrosis in percent × LV angiographic muscle mass/100) in the 13 patients with AVD. After AVR, however, FC was related inversely to EF (P < 0.01, r = −0.69) and to Vmax (P < 0.025, r = −0.63). It is concluded that: (1) in AVD massive pre-operative fiber hypertrophy heralds impaired postoperative LV function; (2) fiber hypertrophy regresses following AVR regardless of the-LV functional state, and (3) the content of fibrous tissue appears to be a determinant of postoperative LV functio

Left ventricular relaxation at rest and during handgrip in aortic valve disease before and after valve replacement

In 14 patients (pts) with aortic valve disease (A VD) left ventricular (LV) relaxation was assessed by the time constant (T) of LV pressure (tipmanometer) fall before and 19 months after successful aortic valve replacement (A VR). 12 control pts (CO) were studied by the same technique. Preoperative LV ejection fraction in AVD (64%) and in CO (69%) did not differ. In AVD T was increased (60 ms) as compared to the CO (38 ms, P< 0.05). During handgrip (HG) there was a similar increase of LV peak systolic pressure (LVSP), heart rate and peak measured contractile element velocity of shortening in A VD and in the CO. L V end-diastolic pressure varied minimally in both groups. T decreased during handgrip in CO (38 to 33 ms, P<0.01) and remained unchanged in A VD. Following AVR T at rest decreased insignificantly to 52 ms, but remained increased (P<0.025) as compared with CO. During postoperative HG however, a decrease to 47ms (P<0.05) was noted. Postoperative angiographic LV muscle mass (105 g/m2) and LVSP at rest (137 mmHg) remained elevated (P<0.02) as compared to CO (72 g/m2; 119 mmHg). It is concluded that (1) in A VD with normal ejection performance L V relaxation at rest is prolonged and the reaction of relaxation to HG is abnormal despite preserved contractile response, (2) following A VR the response of LV relaxation to HG becomes normal and (3) elevated postoperative T at rest appears to be related to residual hypertrophy and probably also to the still increased LVSP rather than to intrinsic disturbances of myocardial relaxatio

Surgical treatment versus medical treatment in hypertrophic obstructive cardiomyopathy

Sixty-three patients operated upon for HOCM and 49 patients selected for non-surgical treatment have been followed-up for 15 years. Pre-operatively, surgical patients had a higher left ventricular outflow tract gradient at rest and, on the average, more severe symptoms than non-surgical patients. Septal myectomy relieved the pressure gradient and symptoms more consistently than long-term treatment with β-blockers or verapamil. Within an average observation time of 7½ years, there was late deterioration or death in almost half of the non-surgical patients but in less than one-quarter in the operated patients. The 10 year mortality rate was 80% in the surgical series and 71% in the non-surgical series. In operated patients, pre-operative symptomatic status was significantly related to early and late mortality. In medically treated patients, mortality was unrelated to symptoms; however, it was significantly lower in patients receiving long term treatment with β-blockers or verapamil. In conclusion, a high basal pressure gradient associated to limiting symptoms is a clear-cut indication for surgery. Other indications are more debatable. In medically treated patients, long-term administration of β-blockers or verapamil is beneficial even without symptoms as it appears to improve prognosi

Lung region segmentation based on computer tomographic images

The article is written for the benefit of hospitals in order to identify segments of the lungs and thereby help in the process of bisecting lungs according to their respective segments during surgery. Further research in this area can also help in identification of various abnormalities related to each segment and also identify abnormal walls of unhealthy lungs. Segmentation of the lungs has not been implemented in reality, as the lung, being an organ with dynamic chest volumes during respiratory cycles, makes it impossible to address changes during respiration unlike fixed structures like the brain. Further, abnormalities situated on the walls of lung segments, make it more difficult to address volume changes concerned with the lungs. The author of this paper has provided a more effective method to identify various lung segments by using various well known segmentation techniques combined together to identify moving lung image segments more effectively

EC5542 Nebraska\u27s One-House Legislature

Extension Circular 5542 is about Nebraska’s one house legislature, why the bicameral is so widely used, and why both methods are so important

Platelet inhibitors versus anticoagulants for prevention of aorto-coronary bypass graft occlusion

The effects of the antiaggregant substance ticlopidine and of the anticoagulant acenocoumarol on patency rates of aorto-coronary bypass grafts were compared in a prospective randomized trial. Ticlopidine, 250 mg b.i.d. was administered orally from the first postoperative day till angiography, while anticoagulation with acenocoumarol was initiated on the second to third postoperative day. Side-effects of ticlopidine were rare and patient management with the standard dosage of this drug was easier than oral anticoagulation. From an initial group of 166 randomized patients 149 completed the trial by coronary angiography three months postoperatively. The 78 patients in the ticlopidine group showed a compliance of 85%. The average prothrombin time in the 71 patients receiving acenocoumarol was 26.9%. Detailed statistical analysis of the two study groups revealed no reason to doubt the correctness of randomization. Coronary angiography showed an average patency rate per patient of 84% with ticlopidine and of 82% with acenocoumarol. This and various other measures of graft occlusion did not reveal any substantial difference in graft patency of patients receiving ticlopidine or acenocoumarol. It is concluded that ticlopidine may well be used instead of anticoagulants forprevention of postoperative occlusion of aorto-coronary bypass graft

Biological measurement beyond the quantum limit

Quantum noise places a fundamental limit on the per photon sensitivity attainable in optical measurements. This limit is of particular importance in biological measurements, where the optical power must be constrained to avoid damage to the specimen. By using non-classically correlated light, we demonstrated that the quantum limit can be surpassed in biological measurements. Quantum enhanced microrheology was performed within yeast cells by tracking naturally occurring lipid granules with sensitivity 2.4 dB beyond the quantum noise limit. The viscoelastic properties of the cytoplasm could thereby be determined with a 64% improved measurement rate. This demonstration paves the way to apply quantum resources broadly in a biological context