Regional left ventricular function in the three main coronary artery territories at rest and during exercise

Summary Twenty consecutive patients (mean age 51.6 years) with persistent severe angina pectoris underwent aorto-coronary bypass surgery receiving an overall of 60 anastomosis. On an average, 9.4±1.5 months p.o. first pass radionuclide ventriculograms (18 to 24 mCi 99 m Technetium-Pertechnetate i.v.) were performed at rest and after excerise. Besides measurement of global ejection fraction (GEF), regional ejection fraction (REF) was assessed employing for the first time a new technique: each RAO-view of p.o. radionuclide left ventriculogram was subdivided into three regions according to supply of the three main coronary arteries and their branches as visualized on pre-operative coronary angiogram.GEF improved after maximum exercise in 13 cases by 8.1% points (from 50.4 to 58.5%), remained unchanged three times and decreased four times by 7.1 points (from 51.6 to 44.5%; all changesp<0.05).In completely revascularized regions (n=35) REF improved 24 times by 9.7 points (from 51.1 to 60.8%), did not differ from rest REF six times and decreased in three case by 7.3 points (from 48.6 to 41.3%; all changesp<0.05). Completely revascularized regions responded to exercise like normally perfused areas (increase 7.8 points (from 50.6 to 58.4%;n=7;p<0.05).REF deteriorated in incompletely revascularized regions (n=9) six times by 12.8 points (from 58.0 to 45.2%), remained unchanged twice and improved once by 4.5 points. Total group's REF decreased by 7.3 points (from 56.8 to 49.5%;p<0.05). Exercise REF of incompletely revascularized regions was highly significant inferior to that of completely revascularized regions (49.5 to 58.4%;p<0.01).GEF is a weighted balance of the three regional ejection fractions. The most important parameter is REF of LAD territory.     

Importance of luxury flow for critically ill patients receiving a left ventricular assist system

The presence of a significant organ dysfunction does not immediately exclude patients from consideration for treatment with a left ventricular assist system (LVAS). However, in treating morbid circulatory shock patients with multiple organ failure, it is important to know the preoperative and postoperative factor or factors related to the recovery of the damaged organ function. In this study, we retrospectively analyzed patients receiving a LVAS at our institution and tried to determine the important factors related to the survival of patients with multisystem failure. Twenty-seven patients who underwent LVAS placement at Saitama Medical School Hospital between 1993 and 2003 were included in this study. The preoperative risk factors analyzed were renal dysfunction, respiratory dysfunction, hepatic dysfunction, the existence of active infection, and the combination of all four factors. As a postoperative factor, the pump flow index (mean LVAS pump flow during the first 2 weeks after LVAS surgery divided by the body surface area) was analyzed. None of the analyzed preoperative factors could predict survival after LVAS surgery, but a pump flow index of less than 2.5 l/min/m² had a significant relationship with death after LVAS surgery. Further analysis revealed that all the patients with a pump flow index of 3.0 l/min/m² or more could overcome preoperative organ dysfunction. Congestive heart failure patients with multisystem failure need luxury pump flow for successful LVAS surgery; this factor could be especially important in device selection and postoperative management.     

Methods for non-invasive detection of ventricular late potentials--a comparative multicenter study

To evaluate the methodological problems of the non-invasive registration of late potentials the results obtained with four different averaging devices in the same 109 patients were compared. The high-resolution ECG was obtained from the body surface, high-gain amplified and filtered. With the averaging technique, the improved signal-to-noise ratio was able to detect low-amplitude cardiac activity. The incidence of late potentials detected with the four averaging systems, whose characteristics are described, ranged between 12% and 21%. Corresponding positive results were obtained in 5.5%, corresponding negative results in 68.8%. The reasons for differing results were mainly due to differences in visual or automatic interpretation of the registered fractionated electrical cardiac activity. Additionally, the determination of the end of QRS using the QRS width, obtained from reference leads, may influence the specificity of the methods.     

Left ventricular function following withdrawal of chronic metoprolol treatment in patients with ischaemic heart disease. A double blind study

The effect on left ventricular function of a gradual withdrawalof chronic metoprolol treatment in postinfarction patients wasstudied. All patients were in a randomized double-blind post-infarctionstudy with metoprolol (M 100–200 mg daily; N=14) or placebo(P; N =18). After three years treatment the study medicationwas gradually withdrawn during one week. M-mode echocardiography,guided by concomitant cross-sectional recordings, were performedbefore, one and 12 weeks after the withdrawal. Treatment (i.e.M or P) had to be reinstituted in eight patients (5 M; 3P) becauseof the development of disabling symptoms during the follow-up.Heart rate was lower in patients treated with M (57±4)than with P (69±10) (p<0.01). One week after withdrawalof M, heart rate had increased to 77± 13(p<0.001),while patients on P showed no significant change. In order tominimize the influence of heart rate on the evaluation of timeintervals in the cardiac cycle, heart rate dependent correctionfactors were used. One week after M withdrawal there was a prolongationof the pre-ejection period (PEP) from 120±15 ms to 133±16ms (p< 0.01), mainly due to a prolongation of the intervalfor early isovolumetric contraction (Q Mc) from 87±10ms to 101±11 ms (N=11; p0.001). Simultaneously, valuesfor isovolumetric relaxation increased from 228±28msto 286±39 MS (n = 11; p0.001), starting from a somewhatlower value than P before withdrawal, reaching an insignificantlyhigher level and returning to the levels of P. During withdrawalof P stable values were encountered. Twelve weeks after withdrawal,there were no longer significant differences between M and Pgroups. In conclusion, after a one week gradual withdrawal ofM in patients with ischaemic heart disease, a transient increaseof both isovolumetric contraction and relaxation phases occur,suggesting depressed myocardial function, despite a transientrebound increase in heart rate.     

Infection of cardiac mural thrombus associated with left ventricular aneurysm

Infection is a rare complication of cardiac mural thrombus andmay prove difficult to diagnose and treat. We describe a patientwith infected thrombus associated with a left ventricular aneurysm,involving Salmonella typhimurium. Cross-sectional echocardiographyproved helpful in establishing the diagnosis.     

Left ventricular function before and after kidney transplantation. A prospective study in patients with juvenile-onset diabetes mellitus

The aim of the present investigation was to discover whetherdisturbed left ventricular (LV) function limits renal replacementtherapy in patients with juvenile onset diabetes mellitus. Seventeenpatients given functioning kidney grafts were studied non-invasively(M-mode echocardiography, apexcardiography, phonocardiography)before renal transplant and an average of six, 13 and 44 monthsafter transplant. The main pretransplant findings were pronouncedLV hypertrophy with impaired diastolic LV function (prolongedrelaxation time + signs of decreased LV distensibility) anda hyperdynamic circulation. Most of these abnormalities were significantly less severe aftersuccessful kidney transplantation. LV mass decreased by 37%44 months after transplant (p<0.01) and LV diastolic andsystolic volumes decreased with a subsequent increase in ejectionfraction from 0.65 to 0.78 (p<0.01). The LV distensibilityand filling pattern improved significantly while the prolongedrelaxation time was unchanged. These findings imply that pretransplant disturbances in LV functionare related more to factors such as hypertension, volume overloadand uraemia than to diabetes per se because no pronounced improvementin the metabolic disorder resulting from diabetes can be expected,even after the most successful transplant. Disturbed LV functionshould not, therefore, exclude uraemic diabetics from renalreplacement.     

A novel approach to delivery of extracorporeal support using a modified continuous flow ventricular assist device in a mid‐volume congenital heart program

Extracorporeal life support (ECLS) is an essential component of a modern congenital cardiac surgery program. The circuit components and bedside management team may, however, vary among institutions. Here, we evaluate our initial experience with a modified ventricular assist device—based ECLS circuit primarily managed by the bedside nurse. We hypothesize that our outcomes are comparable to Extracorporeal Life Support Organization (ELSO) registry data. All patients who received ECLS from January 1, 2016 to December 31, 2019 at a single institution were included. Primary outcomes were survival to ECLS decannulation and discharge or transfer. Secondary outcomes included complications from ECLS. Data were compared to available ELSO registry data. Thirty‐seven patients underwent 44 ECLS runs during the study period. Forty percent of patients had single ventricle physiology. Nearly 46% of patients received ECLS as part of extracorporeal cardiopulmonary resuscitation (eCPR). Survival to ECLS decannulation (68.2%) and survival to discharge or transfer (61.4%) did not differ from overall ELSO outcomes (69.7%, P = .870 and 50.7%, P = .136), as well as survival to discharge or transfer in a comparable cohort of ELSO centers (53.1%, P = .081). Patients with complications had a lower rate of survival to discharge or transfer but this did not reach statistical significance (47.7% vs. 75.0%, P = .455). Neurologic (50.0%), hemorrhagic (45.5%), and renal complications (31.8%) were most common in this cohort. A modified ventricular assist device‐based ECLS circuit with primary management by the bedside nurse can provide comparable support in a neonatal and pediatric cardiac surgery population. Cost analyses and further delineation of the complication profile are necessary for a complete characterization of this system.     

依那普利对原发性高血压患者血清胶原及透明质酸浓度的影响

目的　观察原发性高血压（ＥＨ）患者使用依那普利前后血清Ⅲ、Ⅳ型前胶原、透明质酸的浓度变化;探讨依那普利干预血清前胶原生成以及抑制左室肥厚（ＬＶＨ）形成的作用。方法应用放免技术测定３７例ＥＨ患者及２１例体检正常者血清Ⅲ、Ⅳ型前胶原神经末端肽（ＰⅢＰ、ＰⅣＰ）及透明质酸（ＨＡ）浓度。ＥＨ患者口服依那普利治疗１２周后复测上述指标。结果治疗前ＥＨ组血清ＰⅢＰ、ＰⅣＰ、ＨＡ浓度显著高于对照组（Ｐ＜０．０１）;依那普利治疗后ＥＨ组相应指标较治疗前明显降低（Ｐ＜０．０１）。结论血清ＰⅢＰ、ＰⅣＰ、ＨＡ水平与血压升高密切相关;依那普利在降压的同时,降低血清ＰⅢＰ、ＰⅣＰ、ＨＡ的生成,具有抑制ＬＶＨ的作用。     

低心室容量负荷未能影响兔离体心肌的氧耗反应时间

为了解心肌容量负荷是否影响心肌的氧化磷酸化过程,采用兔离体灌流心肌线粒体氧耗反应时间测定方法,对一下正常心室容量负荷和低心室容量负荷时的心肌线粒体氧耗反应时间进行比较,结果提示心肌作功负荷变化未能影响心肌线粒体的能量代谢动态调节过程。     

QT Dispersion Level and Its Clinical Significance.in Dilated Cardiomyopathy

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