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At least 1,099 records · Page 61Linked to original sources
PubMed1999

Successful orthotopic pig heart transplantation from non-heart-beating donors.

BACKGROUND: With the aim to expand the severely limited donor pool by use of non-heart-beating donors we developed a technique for successful transplantation of hearts after 30 minutes of normothermic ischemia without donor pretreatment. METHODS: In control groups hearts were transplanted in a conventional fashion using crystalloid cardioplegia (Group I, n = 6) or BCP (Group II, n = 8) for induction of cardiac arrest. In the ischemic groups hearts were harvested after 30 minutes of normothermic ischemia, perfused with blood cardioplegia (BCP) (Group III, n = 9) or BCP containing the Na(+)-H(+)-exchange inhibitor HOE 642 (Group IV, n = 8) and transplanted orthotopically. RESULTS: All animals could be weaned from cardiopulmonary bypass. Low dose inotropic support was necessary in the ischemic groups only. Recovery of the maximal left ventricular stroke work index (LVSWImax) in Groups I vs II was 62.6+/-19.6% vs 73.3+/-23.3% (NS), maximal right ventricular stroke work index (RVSWImax) averaged 61.1+/-18.8 vs 87.8+/-31.7% (NS) as compared to the preoperative level. In the ischemic groups (III vs IV) LVSWImax was 27.3+/-11.7 vs 59.5+/-32.4% (p = 0.038), RVSWImax was 27.4+/-20.9 vs 64.2+/-46.6% (NS). CONCLUSIONS: The results indicate that (a) successful pig heart transplantation after 30 minutes of normothermic ischemia is possible without donor pretreatment, and (b) that HOE 642 improves posttransplant LVSWImax significantly.

Animals↗
PubMed1975

[The effect of ischemic and cardioplegic heart standstill on the myocard metabolism in normal and less perfused heart (author's transl)].

The tolerance of ischemia in normal and less perfused myocard during an ischemic and cardioplegic heart standstill was investigated. A decrease of ATP and ADP and an increase of the lactate, pyruvate and AMP was established during an ischemia of 20 minutes. The less perfused hearts gave considerably worse results regarding the energy transformation than normal hearts. In less perfused hearts the energy reserve of myocardial metabolism showed a considerably better behaviour during a cardioplegic heart standstill of 45 minutes than an ischemic one of 20 minutes. During the recuperation period this trend was emphasised.

Adenosine Diphosphate↗
PubMed2006

Delivery of care for adult patients with congenital heart disease in Europe: results from the Euro Heart Survey.

AIMS: The increasing number of adults with congenital heart disease (CHD) has prompted the development of recommendations for the management of these patients and for the organization of their healthcare. The aim of this report is to describe the delivery of care in Europe for adults with congenital cardiac anomalies. METHODS AND RESULTS: As part of the Euro Heart Survey on Adult Congenital Heart Disease, we obtained data from 71 voluntarily participating centres that detailed their care practices for these patients. Forty-eight of these centres were specialist centres and 23 were non-specialist centres. We found that only 19% of the specialist centres complied with defined standards for optimal care structure. The criteria that appeared to be most difficult for all centres to achieve were performing 50 congenital heart operations or more per year and involving nurse specialists in the care of these patients. CONCLUSION: This survey indicated that the provision of care in Europe for adults with congenital heart defects is suboptimal. To fully realize the benefits of cardiac surgery performed in infants and children, continuous effort must be applied by healthcare professionals in order to implement the recommendations on the organization of care for these patients.

Adult↗
PubMed1997

Influence of heart rate, respiration and recipient atrial contraction on pulsed wave transmitral Doppler flow indices in orthotopic heart transplant recipients.

AIMS: The study set out to assess the relative contributions of donor heart rate, respiration and recipient atrial contraction on the mean of pulsed wave transmitral Doppler flow indices in orthotopic heart transplant recipients. This would provide information on the theoretical usefulness of pacemaker synchronization of recipient atrial contraction, as well as on the validity of certain strategies used for pulsed wave Dopper analysis of diastolic left ventricular function, which have excluded beats based on recipient atrial contraction timing. METHODS: Thirty two consecutive patients undergoing orthotopic heart transplantation in our centre were prospectively studied. The following Doppler indices were analysed: peak early diastolic velocity (E) and its area under the Doppler curve (TVIE), diastolic velocity after donor atrial contraction (A) and its area under the curve (TVIA), the total area under the curve (TVI), the isovolumic relaxation period (IVR), the diastolic filling period, the normalized peak filling rate and the pressure half time. RESULTS: Only 81 out of 347 recordings (23%) allowed analysis of the recipient P wave and thus recipient atrial contraction timing, heart rate and the respiration phase in 22 patients for a total of 1579 beats. The isovolumic relaxation period, E, pressure half time and TVIA are not influenced by donor heart rate. For the isovolumic relaxation period, E, TVI and TVIE, respiration contributes as much as recipient atrial contraction timing to beat-to-beat variation. Pressure half time, the diastolic filling period and peak filling rate were not affected by respiration. TVI was not affected by recipient atrial contraction timing. CONCLUSION: With respect to analysis of diastolic function, exclusion of beats based on recipient atrial contraction timing is invalid for the isovolumic relaxation period. E, TVI and TVIE, since these are equally influenced by respiration. Since TVI was not affected by recipient atrial contraction timing, pacemaker synchronization of donor and recipient atria is not expected to be useful in patients with left ventricular diastolic dysfunction.

Atrial Function↗
PubMed1993

Electrophysiological effects of high cocaine concentrations on intact canine heart. Evidence for modulation by both heart rate and autonomic nervous system.

BACKGROUND: Previous clinical reports have suggested that cocaine intoxication may produce severe ventricular arrhythmias due to a direct effect on the heart. However, the effects of high plasma levels of cocaine on the electrophysiology of the heart have not been well characterized and remain poorly understood. METHODS AND RESULTS: The purpose of this study was to characterize the electrophysiological effects of high doses of cocaine on the in situ dog heart. In dogs anesthetized with morphine and alpha-chloralose, cocaine (2-11 micrograms/mL) increased both atrial and ventricular refractory periods and produced rate-dependent increases in atrial, atrioventricular, His-Purkinje, and ventricular conduction intervals. The time constant for the onset of cocaine's conduction slowing effect following a reduction in pacing cycle length from 400 to 260 msec was approximately two beats, and the time constant for diastolic recovery from conduction slowing was approximately 200 msec, which are similar to values reported for several class Ib antiarrhythmic drugs. Cocaine produced a rate-dependent increase in QT interval that was greatest at high heart rates yet produced no change in the ST (QT-QRS) interval. This suggests that high plasma levels of cocaine delay repolarization primarily via slowing of conduction. Cocaine's effects on both atrioventricular and intraventricular conduction were significantly larger in autonomically blocked than in autonomically intact animals. CONCLUSIONS: We conclude that high plasma levels of cocaine, similar to those reported in autopsy reports following fatal cocaine overdose in humans, produce significant rate-dependent conduction slowing effects on atrial, atrioventricular, and ventricular conduction in the in situ heart. These rate-dependent effects are intensified following autonomic blockade.

Animals↗
PubMed2002

[The electric heart assist device for patients on the waiting list for a heart transplant: a bridge too far].

Left-ventricular assist devices are being increasingly used as a bridge to heart transplantation in patients with end-stage heart failure. However, current evidence does not support their widespread application for this indication. Other indications such as cardiogenic shock in acute myocardial infarction, or severe myocarditis may possibly be more fruitful. The use of these devices in the chronic support of patients with end-stage heart failure has recently been evaluated in patients excluded for heart transplantation. Patients treated with an assist device had a better quality of life than patients on drug treatment, and a greater number of them were still alive after two years (23% versus 8%). In the future, novel options such as skeletal muscle cell transplantation, may offer a feasible alternative to heart transplantation.

Cell Transplantation↗
PubMed1991

The effect of heart rate on the working capacity of patients with complete heart block and physiological pacemaker.

The effect of heart rate (HR) on maximum working capacity was studied in 18 patients (mean age 55 years) with a physiological pacemaker implanted for chronic complete heart block of different aetiology. Exercise testing was performed by bicycle ergometry in 3 pacing protocols in randomized sequence, and without the patients knowing the preprogrammed pacing mode: 1) VVI pacing at a rate of 30 beats/min--exercise on heart block; 2) VVI pacing at a rate of 70 beats/min; 3) physiological DDD or QT pacing. While patients with heart block had a mean HR of 54 +/- 16 beats/min and working capacity of 81 +/- 31 W, on VVI 70 pacing the values were 73 +/- 9 beats/min (+35%, p < 0.002) and 100 +/- 45 W (+24%, p < 0.008), respectively. Exercise during physiological pacing led to an increase in HR to 140 +/- 15 beats/min (+169%, p < 0.002) and in working capacity to 130 +/- 52 W (+61%, p < 0.002). Thus, the increment in working capacity was 2.5 times higher on physiological than standard ventricular pacing (p < 0.005) if compared with the working capacity of patients with heart block.

Aged↗
PubMed1990

[Use of artificial heart ventricles in cardiovascular insufficiency of extreme degree and in heart arrest].

Experiments were conducted on 26 mongrel dogs and 10 calves to evaluate the effect of uni- and biventricular bypass created by means of artificial heart ventricle on hemodynamics in acute cardiovascular insufficiency (ACVI) and heart arrest (HA). The use of unilateral right-ventricular (RVB) and left-ventricular bypass (LVB) was shown to be equivocal: in sufficient functional reserve of the left-ventricular myocardium the volume blood flow in the aorta was increased to a greater degree by RVB (to 2.1 +/- 0.3 l/min) than by LVB (to 2.0 +/- 0.5 l/min). Experiments during HA allowed the authors to evaluate selectively the bypasses in maintenance of the systemic blood flow. It was found that in univentricular bypass the other half of the heart had an effect on hemodynamics, which depended on the initial hemodynamic parameters of the divisions of circulation with high and low pressure, the filling of the heart cavities with blood, and the effect produced through the interventricular septum. The increase of the volume blood flow in the aorta in RVB to 0.6 +/- 0.1 l/min is linked to a great measure by the authors with the conducted artificial ventilation of the lungs. It was noted that the greatest difficulties in maintaining the systemic blood flow in ACVI were associated with the development of disproportion of the contractile function of the right and left parts of the heart. With consideration for this circumstance, the indications for univentricular bypass are determined. A clinical case with prolonged use of LVB (8 days) is discussed.

Animals↗
PubMedDate not supplied

Pediatric heart transplantation: surgical considerations for congenital heart diseases.

Congenital anomalies of the atrium, of the pulmonary and systemic venous return, and of the great vessels are sometimes regarded as contraindications to heart transplantation. Among 10 children who underwent heart transplantation in our institution, five, aged 4 to 15 years and weighting 9 to 32 kg, previously operated on, had congenital anomalies. These lesions, encountered singly or in association, were single atrium (2), previous Mustard operation (1), hypoplastic left atrium (1), anomalous systemic venous return (3), anomalous pulmonary venous return (2), transposition or malposition of the great vessels (5), pulmonary artery hypoplasia (1). To enable correction of these lesions and to perform heart transplantation, the donor heart preparation was modified in four ways. The surgical techniques used for correcting these anomalies in this group were atrial septation, atrial enlargement, superior and inferior reroofing, double venous rerouting, septal realignment, full-length mobilization of the great vessels, and pulmonary artery reconstruction. All children survived operation and left the hospital in excellent condition. Follow-up ranged from 6 months to 3 years. All children are totally asymptomatic. As demonstrated by echocardiography, heart catheterization, and angiography, there are no stenoses, no shunts, and there is good atrial size and good orientation of the great vessels. On the basis of our experience, we conclude that with appropriate surgical techniques, most atrial, venous return, and intrapericardial great vessel anomalies are correctable at the time of orthotopic transplantation and that these techniques allow for a successful outcome in children.

Anastomosis, Surgical↗
PubMed1990

Experience with cardiorespiratory support devices in patients undergoing heart and heart-lung transplantation.

During the 2-year period 1987 through 1988, 124 patients were assessed for heart or heart-lung transplantation. Sixty were accepted for heart transplantation, of whom 49 received transplants. Nine required pretransplant intra-aortic balloon pump support (+/- positive-pressure ventilation) for periods ranging from 2 to 15 days (mean 5 days). One patient was supported successfully by a pneumatic biventricular assist device for 70 days pretransplant. The 30-day survival in this group of 10 critically unstable patients was 100% and the 6-month survival 90% (one death). This experience compares well with survival rates of 100% at 30 days and 92% at 6 months in the 39 patients who required no form of pretransplant circulatory support. The biventricular assist device also has been used in 2 other patients; one did not survive to transplant and the other was deemed unsuitable by virtue of cerebral injury. Extracorporeal membrane oxygenation supported 2 posttransplant patients (one heart and one heart-lung) with grossly impaired pulmonary function for periods of 5 and 2 days respectively, but both died before lung function had recovered.

Adult↗
PubMed1990

[Use of an artificial heart and ventricular support system before heart transplantation].

Acute, uncontrollable heart failure in young candidates for transplantation should be considered an indication for implantation of an artificial heart or artificial support of the hear ventricle, if a suitable graft for transplantation is not available at the time. It may be assumed that the two systems will ensure an adequate circulation and will improve organ function. The success of two-stage transplantation is cca 50%. Postoperative haemorrhage and infection are a major problem. Infection after implantation of an artificial heart is frequently incurable and is a clear contra-indication for further implantation. Thromboembolism caused by the artificial blood pump does not seem to be a serious complication when used temporarily. As none of the patients died due to failure of the pump and as also the other problems associated with the use of an artificial heart or a supporting device were successfully resolved, research and development of artificial blood pumps should proceed. Clinical results also confirmed the success of two-stage transplantation of the heart.

Heart Transplantation↗
PubMed1987

[Increased concentrations of atrial natriuretic peptide in the plasma and heart atrium of patients with aortic and mitral valve diseases compared to patients with coronary heart disease].

Plasma levels of atrial natriuretic peptide (ANP) and tissue content of the peptide were measured simultaneously in 18 patients with coronary heart disease (group A) and 10 patients with aortic or mitral dysfunction (group B) undergoing open heart surgery. Plasma levels of ANP were significantly higher in patients with valvular heart disease compared to those with coronary heart disease (816 +/- 246 pg/ml versus 232 +/- 58 pg/ml, p less than 0.005). Similarly, tissue levels of ANP in the right atrium of group B doubled that of group A (227 +/- 46 micrograms/g versus 129 +/- 15 micrograms/g, p less than 0.025). Plasma levels and tissue content of ANP were not correlated. However, plasma ANP levels and mean pulmonary artery pressure were positively correlated (r = 0.688, p less than 0.05). Chronic stimulation of ANP secretion leads to a tissue accumulation of natriuretic peptide in heart atrium.

Aged↗
PubMed1988

[Heart and heart-lung transplantation in the child. Indications, methods and results].

Over a 20 month period, 19 children aged 13 days to 15 years (10 under 3 years), received a heart transplantation (isolated: 16 cases, heart-lungs: 3 cases). There were 5 early deaths and 2 during the 3rd postoperative month (total: 44%). Postoperative period is currently over for 8 of the 9 survivors, who lead a normal life, with rather simple constraints: oral cyclosporin-azathioprine immunosuppressive therapy, monthly evaluation in the out-patient department. The method is relatively simple when it concerns heart transplantation. It is quite heavier and complex when it concerns heart-lung transplantation. On the whole, subject to a rigorous selection of the transplant (whose later dysfunction was the major cause of failure, with bacterial or viral infections), these methods find reasonable indications in a number of heart and/or lung malformations or dysfunctions inaccessible to conventional treatments or which used up their resources, making short-term death likely.

Adolescent↗
PubMedDate not supplied

Combined Registry for the Clinical Use of Mechanical Ventricular Assist Pumps and the Total Artificial Heart in conjunction with heart transplantation: sixth official report--1994.

BACKGROUND: The Combined Registry has existed since 1985 with a design toward the voluntary submission of data from centers undertaking mechanical circulatory assistance. METHODS: The compiled results of the Combined Registry for the Clinical Use of Mechanical Ventricular Assist Pumps and the Total Artificial Heart was reviewed and subjected to strict statistical evaluation. RESULTS: More than 2000 implanted devices have been reported through January 1994, and 584 of these have been placed with the intention of bridge to heart transplantation. Nearly 70% of these patients have subsequently undergone heart transplantation, and 69% of those patients have survived to discharge from the hospital. Outcome statistics continue to favor isolated left ventricular support, although only discharge rates are significantly improved over right (p = 0.01) or biventricular assistance (p < 0.001) and the total artificial heart (p < 0.001). Within the group of left ventricular devices no individual mode of support proved advantageous over the others for transplantation or discharge rates. The 30-day mortality for all devices is approximately 36%, which remains much higher than that for orthotopic heart transplants. Isolated left ventricular support, however, had a 30-day mortality of only 9% with similar improvement in 12- and 24-month survival. CONCLUSIONS: These data show the continued success with these devices for bridging critically ill patients to transplantation. Additionally, it supports the ongoing development of devices implanted for long-term use, which might replace orthotopic transplantation for those patients currently deemed marginal candidates.

Adolescent↗
PubMed1994

A collaborative approach to using new technologies for the management of heart disease at the University of Ottawa Heart Institute.

Nursing in the Cardiac Operating Rooms and Catheterization Laboratories at the University of Ottawa Heart Institute has played a collaborative role in advancing and promoting the use of new technologies for treating heart disease. This has been demonstrated in the Catheterization Laboratories with the introduction of such procedures as angioplasties, atherectomies, stents and rotablators and in the Cardiac Operating Rooms with heart transplants and total artificial heart implants. Currently, nurses in the Operating Rooms are actively involved in research on the electrohydraulic totally implantable ventricular assist device (EVAD) which is an internal pump to assist the left ventricle to eject blood into the systemic circulation. Clinical and research professionals work together so that any problems related to using new technologies are identified and solved during both the planning and implementation stages. This article will focus on the collaborative process as it was used for the Artificial Heart Program and on new technologies related to the implant of the electrohydraulic ventricular assist device.

Heart Diseases↗
PubMed1976

[The definition of heart failure with the product of minimal transit time and heart frequency (author's transl)].

The product of minimal transit time (MTT) and heart frequency (HF) defines the number of heart beats which are necessary to transport the blood in a determined region of the circulatory system. According to own studies in physiological (stress) and pharmacological conditions this product is constant, independent from body size, length, age etc. In proportion to the degree of heart failure the MTT X HF increases. Measuring appropriate regions of the circulatory system, right and left heart failure can easily be determined. The method has the advantage of a noninvasive procedure and gives exact quantitive accessment of the pump performance of the heart. In view of the increasing use of radio-nuclides this procedure can be recommended because of its good reliability causing little or no discomfort to the patient, and making it applicable, even under extreme conditions, for instance in a CCU.

Dye Dilution Technique↗
PubMed1998

Heart transplantation for hypoplastic left heart syndrome: modified technique for reducing circulatory arrest time.

BACKGROUND: The surgical technique of heart transplantation as therapy in infants with hypoplastic left heart syndrome was first reported over a decade ago. Since that time, incremental refinements have evolved that both facilitate the operation and potentially reduce the perceived neurologic hazards associated with the use of hypothermic circulatory arrest. METHODS: Minor technical adjustments have permitted infant heart transplantation to be accomplished with relative ease while markedly limiting the need for complete circulatory arrest. Low-flow hypothermic systemic perfusion is used for atrial implantation, reserving circulatory arrest for arch reconstruction only. This is accomplished by use of an active (pump) sucker for venous return. RESULT: Mean circulatory arrest time with the current technique has been 26 minutes. CONCLUSION: Minor technical refinements have resulted in a marked reduction in hypothermic circulatory arrest time during infant heart transplantation for hypoplastic left heart syndrome.

Cardiopulmonary Bypass↗