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Background and Purpose: It is unknown what the optimal anticoagulant level is to prevent thromboembolic stroke in patients with left ventricular assist device (LVAD) support. We aimed to evaluate the relation between coagulation status and the occurrence of thromboembolic stroke in HeartMate-II LVAD assisted patients., Methods: Thirty-eight consecutive patients with a HeartMate-II LVAD were included. Coagulation status was classified according to INR and aPTT ratio at: 1) the moment of first thromboembolic stroke; and 2) during the two weeks preceding the first thromboembolic stroke to assess long-term coagulation status. In patients without stroke, coagulation status was determined just before heart transplant, VAD explantation or death, whichever came first, and at two weeks preceding these surrogate endpoints. Based on coagulation status, patients were divided in two groups: Group I (reference group) was defined as INR below 2 and aPTT ratio below 1.5; Group II (adequate anticoagulation) as INR above 2 or aPTT ratio above 1.5. Logistic regression analysis was performed to assess the odds ratio for developing stroke for patients with adequate anticoagulation compared to the reference Group., Results: Thromboembolic stroke occurred in six (16 %) patients, none within 2 weeks after LVAD implantation. Considering coagulation status at the time of event, patients in coagulation Group II had no decreased risk for thromboembolic stroke (OR 0.78; 95 % CI 0.12-5.0). Results for coagulation status 2 weeks prior of event could not be calculated as all six strokes occurred in Group II., Conclusion: In our experience anticoagulation within predefined targets is not associated with a reduced thromboembolic stroke risk in patients with a HeartMate-II LVAD on antiplatelet therapy. However, no firm statement about the effect of either anticoagulant or antiaggregant therapy can be made based on our study. A larger randomized study is needed to support the hypothesis that there may be no additional benefit of coumarin or heparin therapy compared with antiplatelet therapy alone.

Objectives: During support with a left ventricular assist device (LVAD), partial reverse remodelling takes place in which fibrosis plays an important role. In this study, we analysed the histological changes and expression of fibrotic markers in patients with advanced heart failure (HF) during continuous-flow LVAD (cf-LVAD) support., Methods: In 25 patients, myocardial tissue at the time of LVAD implantation (pre-LVAD) was compared with tissue from the explanted left ventricle (post-LVAD). Interstitial fibrosis and cardiomyocyte size were analysed pre- and post-LVAD. Plasma was obtained from all patients before and during LVAD support. Plasma levels, cardiac mRNA and protein expression of brain natriuretic peptide (BNP), galectin-3 (Gal-3), connective tissue growth factor (CTGF), osteopontin (OPN) and transforming growth factor β-1 were determined., Results: Fibrosis increased during cf-LVAD unloading (P < 0.05). Cardiomyocytes elongated (P < 0.05), whereas cross-sectional area did not change. BNP, Gal-3, CTGF and OPN were significantly elevated pre-LVAD in comparison with controls. BNP decreased significantly after 1 month of cf-LVAD support (P < 0.001) to near-normal levels. Pro-fibrotic markers remained elevated in comparison with controls., Conclusions: cf-LVAD support is associated with lengthening of cardiomyocytes, without alterations in diameter size. Remarkably, myocardial fibrosis increased as well as circulating pro-fibrotic markers. Whether the morphological changes are a direct effect of reduced pulsatility during cf-LVAD support or due to HF progression requires further investigation., (© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Primary cardiac sarcomas often strike young, healthy patients and tend to have a dismal prognosis. Because of limited experience, the heterogeneous nature of cardiac sarcomas and different treatment results of patients with malignant primary tumours of the heart, the role of heart transplantation should be weighed on a case-by-case basis.

Objectives: Continuous-flow left ventricular assist devices (cf-LVADs) may induce commissural fusion of the aortic valve leaflets. Factors associated with this occurrence of commissural fusion are unknown. The aim of this study was to examine histological characteristics of cf-LVAD-induced commissural fusion in relation to clinical variables., Methods: Gross and histopathological examinations were performed on 19 hearts from patients supported by either HeartMate II (n = 17) or HeartWare (n = 2) cf-LVADs and related to clinical characteristics (14 heart transplantation, 5 autopsy)., Results: Eleven of the 19 (58%) aortic valves showed fusion of single or multiple commissures (total fusion length 11 mm [4-20] (median [interquartile range]) per valve), some leading to noticeable nodular displacements or considerable lumen diameter narrowing. Multiple fenestrations were observed in one valve. Histopathological examination confirmed commissural fusion, with varying changes in valve layer structure without evidence of inflammatory infiltration at the site of fusion. Commissural fusion was associated with continuous aortic valve closure during cf-LVAD support (P = 0.03). LVAD-induced aortic valve insufficiency developed in all patients with commissural fusion and in 67% of patients without fusion. Age, duration of cf-LVAD support and aetiology of heart failure (ischaemic vs dilated cardiomyopathy) were not associated with the degree of fusion., Conclusions: Aortic valve commissural fusion after support with cf-LVADs is a non-inflammatory process leading to changes in valve layer structure that can be observed in >50% of cf-LVAD patients. This is the first study showing that patients receiving full cf-LVAD support without opening of the valve have a significantly higher risk of developing commissural fusion than patients on partial support.

Objectives: We evaluated our single-centre clinical experience with the HeartMate II (HM II) left ventricular assist device (LVAD) as a bridge to transplantation (BTT) in end-stage heart failure (HF) patients., Methods: Survival rates, echocardiographic parameters, laboratory values and adverse events of 85 consecutive patients supported with a HM II were evaluated., Results: Overall, mean age was 45 ± 13 years, 62 (73%) were male and non-ischaemic dilatated cardiomyopathy was present in 60 (71%) patients. The median duration of mechanical support was 387 days (IQR 150-600), with a range of 1-1835 days. The 6-month, 1-, 2-, 3- and 4-year survival rates during HM II LVAD support were 85, 81, 76, 76 and 68%, respectively. Echocardiographic parameters demonstrated effective left ventricular unloading, while laboratory results reflected adequate organ perfusion. However, HM II support was associated with adverse events, such as infections in 42 patients (49%; 0.67 events/patient-year), cardiac arrhythmia in 44 (52%; 0.86 events/patient-year), bleeding complications in 32 (38%; 0.43 events/patient-year) and neurological dysfunction in 17 (20%; 0.19 events/patient-year)., Conclusions: In view of the increasing shortage of donor hearts, HM II LVAD support may be considered a life-saving treatment in end-stage HF patients, with good survival. However, it is still associated with some serious adverse events, of which neurological complications are the most critical.

Left ventricular assist devices (LVADs) are increasingly being used as a bridge to heart transplantation or destination therapy. It is unclear which antithrombotic regimen should be used to reduce the risk of stroke. We systematically reviewed the literature on all types of antithrombotic regimens and stroke in patients with any type of LVADs. Our primary outcome measure was the mean incidence of any type of stroke. Twenty-six articles were selected as relevant, comprehending 1989 patients with a mean LVAD support of 200 days (range 30-621). The mean proportion of patients affected with stroke was 20% (range 0-55%), with a mean incidence of 0.74 (range 0-6.91) events/patient-year. Support with HeartMate II and a regimen of postoperative heparin converted to coumarins, acetylsalicylic acid (ASA) and dipyridamole resulted in 0.17 (mean; range 0.06-0.29) strokes/patient-year. HeartMate II support and the same regime without heparin was associated with 0.07 (mean; range 0.03-0.11) strokes/patient-year. A Novacor device with heparin, converted to coumarins, was associated with 3.82 (mean; range 1.03-6.91) strokes/patient-year, while ASA added to this regime resulted in 0.97 ischaemic strokes/patient-year (mean; range 0.53-1.48). Other combinations of assist devices and antithrombotic regimes were investigated in one or two studies only. This systematic review provides risk estimates for stroke for various LVADs and antithrombotic regimes. Our findings indicate that the postoperative use of heparin in HeartMate II patients is doubtful, and suggest an important role for antiplatelet drugs to prevent stroke in patients supported with a Novacor device.

Today, continuous-flow left ventricular assist devices (cf-LVADs) are implanted more often in patients with end-stage heart failure. Because of greater durability they can be implanted for an extended period of time. As a result of increased numbers of patients on cf-LVAD support, healthcare professionals should be aware of the potential complications inherent to this therapy. Both bleeding and thrombosis may occur, and also complications related either to the device itself or to the ensuing altered haemodynamics, valvular pathology, and rhythm disturbances such as ventricular tachycardias and fibrillation. Accurate clinical evaluation, together with an electrocardiogram and, if necessary, combined with an echocardiogram, is obligatory in these situations. This review summarizes common complications complemented by a few clinical cases.

Aims: Caused by ageing of the population, better survival from ischaemic heart disease, and improved treatment of chronic heart disease, the incidence of heart failure has increased enormously. Worldwide, left ventricular assist devices (LVADs) are increasingly being used as a bridge or alternative to heart transplantation. In this study, we investigated whether there is difference in functional and haemodynamic recovery after implantation of pulsatile and continuous-flow pumps., Methods and Results: We compared laboratory and echocardiographic data and exercise performance in patients with end-stage heart failure, before and 3 months after implantation of pulsatile and continuous-flow LVADs. A significant improvement in all laboratory parameters after implantation of both types of LVADs was seen, as well as a significant decrease in heart rate and LV dimensions, indicating better haemodynamics and cardiac recompensation. This improvement was better for the pulsatile device, probably due to higher plasma levels and higher LV dimensions before implantation. Exercise capacity strongly improved: 3 months after implantation of pulsatile and continuous-flow LVADs, peak VO(2) was 20.2 ± 4.8 vs. 18.3 ± 4.8 mL/kg/min (P = 0.09) (53 ± 12 vs. 49 ± 11% of predicted for age and gender) (P = 0.28)., Conclusion: Pulsatile and continuous-flow LVADs result in extensive haemodynamic recovery and exercise performance compatible with daily life activities. Exercise performance with continuous-flow LVADs is equal to that with pulsatile devices. This, in combination with improved survival of the newer devices, allows its use as an alternative to heart transplantation in selected patients.

Background: A growing number of patients with end-stage heart failure undergo implantation of ventricular assist devices as a bridge to heart transplantation., Objectives: In this study we investigated whether functional and haemodynamic recovery after implantation is sufficient to warrant the use of them as long-term alternative to heart transplantation., Methods: We compared peak VO(2) of a group of patients three months after implantation of a ventricular assist device and three months after heart transplantation. Furthermore, we analysed the degree of haemodynamic recovery, by comparing plasma levels of BNP and creatinine before and after implantation of the device., Results: After implantation of a ventricular assist device, exercise capacity improved considerably; three months after implantation peak VO(2) was 20.0+/-4.9 ml/kg/min (52% of predicted for age and gender). After heart transplantation exercise capacity improved even further; 24.0+/-3.9 ml/ kg/min (62% of predicted for age and gender) (p<0.001). In the three months after implantation, BNP plasma levels decreased from 570+/-307 pmol/l to 31+/-25 pmol/l and creatinine levels decreased from 191+/-82 mumol/l to 82+/-25 mumol/l, indicating significant unloading of the ventricles and haemodynamic recovery., Conclusion: With regard to functional and haemodynamic recovery, the effect of implantation of a ventricular assist device is sufficient to justify its use as an alternative to heart transplantation. (Neth Heart J 2008;16:41-6.).

Based on the changes in the field of heart transplantation and the treatment and prognosis of patients with heart failure, these updated guidelines were composed by a committee under the supervision of both the Netherlands Society of Cardiology and the Netherlands Association for Cardiothoracic surgery (NVVC and NVT).THE INDICATION FOR HEART TRANSPLANTATION IS DEFINED AS: 'End-stage heart disease not remediable by more conservative measures'.CONTRAINDICATIONS ARE: irreversible pulmonary hypertension/elevated pulmonary vascular resistance; active systemic infection; active malignancy or history of malignancy with probability of recurrence; inability to comply with complex medical regimen; severe peripheral or cerebrovascular disease and irreversible dysfunction of another organ, including diseases that may limit prognosis after heart transplantation.Considering the difficulties in defining end-stage heart failure, estimating prognosis in the individual patient and the continuing evolution of available therapies, the present criteria are broadly defined. The final acceptance is done by the transplant team which has extensive knowledge of the treatment of patients with advanced heart failure on the one hand and thorough experience with heart transplantation and mechanical circulatory support on the other hand. (Neth Heart J 2008;16:79-87.).

BACKGROUND.: Due to the shortage of donor hearts, mechanical circulatory support is increasingly being used as a bridge to transplantation. In order to allow for more widespread use of ventricular assist devices it is mandatory that patients are not continuously hospitalised. We present the results of our experience with patients with end-stage heart failure, discharged from hospital after implantation of a ventricular assist device and followed in an outpatient setting. METHODS.: After an intensive training and education programme, focusing on the management of the percutaneous driveline and instructions on how to handle in case of an alarm or malfunction of the device, patients were discharged. They were followed in the outpatient department. All regular and unplanned visits were registered, including readmissions. RESULTS.: Twenty-seven patients treated with a ventricular assist device were discharged from hospital. There were 37 extra visits, of these, 27 were device related resulting in 21 readmissions (0.78/patient). We treated eight infectious episodes in four patients, all device related. Furthermore seven thromboembolic episodes occurred in four patients. One patient died because of multiorgan failure seven weeks after he was readmitted with an urosepsis. In our experience of 11.4 patient years at home while on the device, only 5% of the time was spent in hospital for complications. In comparison with patients on an assist device who stayed in hospital until transplantation, there were no more complications. CONCLUSION.: This study demonstrates that patients with end-stage heart failure, treated with a ventricular assist device, can be safely discharged from hospital, with an acceptable rate of readmissions. It results in a fair quality of life, with a high degree of independence of the patient. (Neth Heart J 2007;15:45-50.).

Heart transplantation is limited by the lack of donor organs. Twenty years after the start of the Dutch transplant programmes in Rotterdam and Utrecht the situation has even worsened, despite efforts to increase the donor pool. The Dutch situation seems to be worse than in other surrounding countries, and several factors that may influence donor organ availability and organ utilisation are discussed. The indications and contraindications for heart transplantation are presented, which are rather restrictive in order to select optimal recipients for the scarce donor hearts. Detailed data on donor hearts, rejected for transplantation, are shown to give some insight into the difficult process of dealing with marginal donor organs. It is concluded that with the current low numbers of acceptable quality donor hearts, there is no lack of capacity in the two transplanting centres nor is the waiting list limiting the number of transplants. The influence of our current legal system on organ donation, which requires (prior) permission from donor and relatives, is probably limited. The most important determinants of donor organ availability are: 1. The potential donor pool, consisting of brain dead victims of (traffic) accidents and CVAs and 2. Lack of consent to a request for donation. The potential donor pool is remarkably small in the Netherlands, due to relatively low numbers of (traffic) accidents, with an almost equal number of CVA-related brain dead patients compared with neighbouring countries. Lack of consent can only be pushed back by improved public awareness of the importance of donation and improved skills of professionals in asking permission in case there is no previous consent.

In trying to assess the benefit of cardiac surgery in AIDS patients, the question arises whether a patient with a deficient immune system can tolerate open heart surgery well enough to make the operation worthwhile. Surgical procedures and cardiopulmonary bypass have been noted to alter immune function (Diettrich et al., Ide et al.). Therefore, the presence of clinical AIDS is often still regarded as a contraindication to cardiac surgery. In this report we describe an AIDS patient who developed endocarditis of the native aortic valve. The endocarditis was successfully treated with antibiotic drugs, but the patient was left with damaged valves. Over the months he developed a massive aortic insufficiency and underwent aortic valve replacement. The patient did well after surgery, and is alive and well 18 months after the operation, suggesting that cardiac surgery might be a good and valuable treatment option in AIDS patients.

Objective: To evaluate the use of left ventricular assist devices (LVAD) as bridge to heart transplantation (HTx) in patients with end-stage heart failure., Method: Between March 1993 and December 2001, 38 patients with refractory end-stage heart failure underwent HeartMate LVAD (Thoratec, Pleasanton Calif.) implantation., Results: A total of 33 of the 38 patients (87%) survived the implantation and perioperative period. There were five perioperative deaths (13%), two due to right ventricular failure, two as a result of bleeding and one probably due to septic shock at the time of LVAD implantation. Three patients (9%) died late in the postoperative period due to septic shock, mechanical failure of the device and a cerebral embolus resulting from LVAD endocarditis, initiated by an acute cholecystitis. Twelve patients (32%) had one or more infectious episodes during long-term assist, of which one patient died. Four patients are still on the device, waiting for a heart transplantation. Twenty-six patients (76%) underwent HTx after 206±129 days of support., Conclusion: These results show the efficacy of LVAD support as a bridge to heart transplantation in patients with end-stage heart failure. Major long-term complications are infections and mechanical failure of the device.

Objectives: We sought to evaluate the contractile proteins in cardiomyocytes of patients with end-stage heart failure (HF) before and after mechanical support with a left ventricular assist device (LVAD)., Background: Improvement of myocyte dysfunction has been suggested after LVAD support., Methods: Fourteen patients' myocardial biopsies taken at the time of LVAD implantation and after explantation, at the time of heart transplantation, were processed for routine hematoxylin-eosin staining and immunohistochemistry using monoclonal antibodies against actin, myosin, tropomyosin, troponin C and T and titin. A grading scale from 1 (abnormal staining of all myocytes, no cross-striation) to 5 (normal fiber anatomy and striation) was used. The cross-sectional area of cardiomyocytes was also measured., Results: The cardiomyocytes' cross-sectional area decreased after support, from 519 +/- 94 microm(2) to 319 +/- 53 microm(2) (p < 0.001). Actin, tropomyosin, troponin C, troponin T and titin at the time of LVAD implantation showed widespread distortion of architecture; their grades were 1.4 +/- 0.6, 2.3 +/- 1.0, 2.1 +/- 0.9, 2.1 +/- 1.2 and 2.0 +/- 0.6, respectively. In contrast, myosin morphology was preserved (4.6 +/- 0.7). After LVAD support, actin, tropomyosin, troponin C, troponin T and titin showed improvement (grades 2.7 +/- 1.3 [p = 0.004], 3.2 +/- 1.2 [p = 0.021], 3.3 +/- 0.9 [p = 0.004], 3.0 +/- 1.1 [p = 0.048] and 3.1 +/- 0.9 [p = 0.001], respectively), but no normalization. The myosin pattern deteriorated slightly (3.6 +/- 1.6 [p = 0.058])., Conclusions: After LVAD support, during a period of 213 +/- 135 days in patients with end-stage HF, despite a decrease in the size of the cardiomyocytes, severe structural myocyte damage persisted. This does not support complete recovery of myocyte histologic features.

Objectives: We sought to study exercise capacity at different points in time after left ventricular assist device (LVAD) implantation and subsequent heart transplantation (HTx)., Background: The lack of donor organs warrants alternatives for transplantation., Methods: Repeat treadmill testing with respiratory gas analysis was performed in 15 men with a LVAD. Four groups of data are presented. In group A (n = 10), the exercise capacities at 8 weeks and 12 weeks after LVAD implantation were compared. In group B (n = 15), the data at 12 weeks are presented in more detail. In group C (n = 9), sequential analysis of exercise capacity was performed at 12 weeks after LVAD implantation and at 12 weeks and one year after HTx. In group D, exercise performance one year after HTx in patients with (n = 10) and without (n = 20) a previous assist device was compared., Results: In group A, peak oxygen consumption (Vo2) increased from 21.3+/-3.8 to 24.2+/-4.8 ml/kg body weight per min (p < 0.003), accompanied by a decrease in peak minute ventilation/ carbon dioxide production (VE/Vco2) (39.4+/-10.1 to 36.3+/-8.2; p < 0.03). In group B, peak Vo2 12 weeks after LVAD implantation was 23.0+/-4.4 ml/kg per min. In group C, levels of peak Vo2 12 weeks after LVAD implantation and 12 weeks and one year after HTx were comparable (22.8+/-5.3, 24.6+/-3.3 and 26.2+/-3.8 ml/kg per min, respectively; p = NS). In group D, there appeared to be no difference in percent predicted peak Vo2 in patients with or without a previous LVAD (68+/-13% vs. 74+/-15%; p < 0.37), although, because of the small numbers, the power of this comparison is limited (0.45 to detect a difference of 10%)., Conclusions: Exercise capacity in patients with a LVAD increases over time; 12 weeks after LVAD implantation, Vo2 is comparable to that at 12 weeks and one year after HTx. Previous LVAD implantation does not seem to adversely affect exercise capacity after HTx.

Off-pump coronary artery bypass grafting requires immobilization of the coronary artery. A suction device (Octopus Tissue Stabilizer), attached to the epicardium and connected rigidly to the operating table rail, was used through limited and full surgical access for single-vessel and multivessel arterial revascularization, respectively. An outline for its application, as used by us to construct 122 anastomoses in 70 patients, including posterior wall grafting (in 9 patients) and sequential grafting on the anterior wall (in 17 patients), is presented.

Objective: Cardiopulmonary bypass and global cardiac arrest enable safe coronary artery bypass grafting but have adverse effects. In off-pump coronary bypass grafting, invasiveness is reduced, but anastomosis suturing is jeopardized by cardiac motion. Therefore the key to successful off-pump coronary bypass grafting is effective local cardiac wall stabilization., Methods: We prospectively assessed the safety and efficacy of the Octopus tissue stabilizer (Medtronic, Inc., Minneapolis, Minn.) in the first 100 patients selected for off-pump coronary bypass via full or limited surgical access. To immobilize and expose the coronary artery, two suction paddles (-400 mm Hg), fixed to the operating table-rail by an articulating arm, stabilized the anastomosis site., Results: One hundred forty-one grafts (96% arterial) were used to create 172 anastomoses (17% side-to-side), up to 4 per patient, on average 23 in the full access group (46 patients) and 1.2 in the limited access group (54 patients). Complications included conversion to cardiopulmonary bypass (2%), conversion from limited to full access (3%), myocardial infarction (4%), predischarge coronary reintervention (2%), and late coronary reintervention (1%). Median postoperative length of hospital stay was 4 days (limited access) or 5 days (full access). Rapid recovery allowed 96% of patients to resume social activities within 1 month. At the 6-month angiographic follow-up, 95% of anastomoses was patent. At the 2- to 22-month follow-up (mean, 13 months), 98 patients were in Canadian Cardiovascular Society class I and 2 patients were in class II., Conclusion: These results suggest that off-pump coronary artery bypass grafting with the Octopus tissue stabilizer is safe. Early clinical outcome and patency rates warrant a randomized study comparing this methods with conventional coronary bypass grafting.

Objective: Target site immobilization is essential to enable meticulous anastomosis suturing during coronary artery bypass grafting on the beating heart. A novel device ('Octopus') was developed for local heart muscle immobilization by suction. The purpose of this study was to investigate the efficacy of the method through a limited access., Methods: The suction device, placed on either side of the recipient coronary artery and fixed to the operating table-rail through an arm construction, restrains anastomosis site motion to 1 x 1 mm. A total of 27 patients underwent off-pump arterial bypass grafting using this method. Preoperatively, all patients had angina class III (NYHA) and were failed or unsuitable candidates for balloon angioplasty. Surgical access was via a 10-cm anterior thoracotomy (n = 26) or 10-cm subxiphoid incision (n = 1)., Results: Harvesting of the graft required 48 +/- 12 min (mean +/- S.D.). Immobilization with the 'Octopus' was effective and facilitated precise anastomosis suturing of 20 single and 7 sequential grafts. Immobilization did not change cardiac index and mean arterial blood pressure. During coronary surgery, however, inotropic drug support was used in 5 of 27 (18%) of patients. There was no myocardial infarction. Only minor transient complications were met. There were electro-cardiographical signs of pericarditis in 6 patients. The postoperative hospital stay ranged from 2 to 6 days, mean 4.0 +/- 1.2 days. The mean follow-up is 6.5 +/- 4 months (range, 1-12 months). All patients except one were in functional class I without angina. Social activities were resumed within 4 weeks. At 6 months angiography was performed in 15 out of 27 patients. The patency rate of 19 out of 20 anastomoses was 95%. All distal grafts were patent. One side to side anastomosis was occluded., Conclusions: The 'Octopus' immobilization method is safe and effective. It facilitates less invasive CABG in selected patients and gives way to fast recovery by reducing invasiveness.

Background: Although strict selection criteria are being used for the acceptance of human donor hearts for transplantation, problems with respect to functional recovery on reperfusion sometimes still occur. Therefore, evaluation of the viability of a human donor heart before implantation during heart transplantation may be of great value., Methods and Results: In the present study, the energy metabolism of 25 excised human donor hearts arrested with St Thomas' Hospital No. 2 cardioplegic solution was evaluated noninvasively by use of 31P magnetic resonance spectroscopy (MRS) before implantation and was correlated with myocardial function measured with thermodilution in heart transplant patients. No significant correlation was observed between the cardiac index of heart transplant patients during the first hours after transplantation and the phosphocreatine/ATP (r = .13, P = .54), inorganic phosphate/ATP (r = .26, P = .21), phosphomonoesters/ATP (r = .02, P = .92), or phosphocreatine/inorganic phosphate (r = .16, P = .44) ratio or the intracellular pH (r = .06, P = .78) at the time of reperfusion. However, 1 week after transplantation, a significant correlation was observed between the cardiac index and the phosphocreatine/ATP (r = .49, P = .01), phosphomonoesters/ATP (r = .45, P = .02), and phosphocreatine/inorganic phosphate (r = .40, P = .05) ratios at the time of reperfusion. In contrast, the inorganic phosphate/ATP (r = .10, P = .63) ratio and pH (r = .31, P = .13) at the time of reperfusion showed a poor correlation with the cardiac index 1 week after transplantation., Conclusions: Functional recovery after human heart transplantation is related to the metabolic condition of the hypothermic donor heart.

Objectives: We sought to investigate the origin of the fractionated electrogram and its relations to abnormal conduction in cardiomyopathic myocardium., Background: Patients with dilated cardiomyopathy have a high incidence of ventricular tachycardias. Electrograms recorded in these patients are often fractionated., Methods: High resolution mapping (200-microM interelectrode distance) of the electrical activity was carried out in 11 superfused papillary muscles and 6 trabeculae from 7 patients who underwent heart transplantation because of dilated cardiomyopathy. Similar measurements were taken in four papillary muscles from dog hearts in which electrical barriers had been artificially made. Ten human preparations were studied histologically., Results: All preparations revealed sites with fractionated electrograms. In three human preparations, activation patterns showed a discernible line of activation block running parallel to the fiber direction. Fractionated electrograms were recorded at sites contiguous to the line of block. In five preparations, fractionated electrograms were recorded at sites where lines of block were not identified. In these preparations, electrical barriers consisted of short stretches of fibrous tissue. In the remaining nine preparations, fractionated electrograms were recorded, both from sites contiguous to distinct obstacles and sites without evidence of a barrier., Conclusions: Our observations showed that fractionated electrograms recorded in myocardium damaged by cardiomyopathy were due to both distinct, long strands and short stretches of fibrous tissue. Delayed conduction was caused by curvation of activation around the distinct lines of block and by the wavy course of activation between the short barriers. The latter reflects extreme nonuniform anisotropy.

Background: Ventricular tachycardias occurring in the chronic phase of myocardial infarction are caused by reentry. Areas of slow conduction, facilitating reentry, are often found in the infarcted zone. The purpose of this study was to elucidate the mechanism of slow conduction in the chronic infarcted human heart., Methods and Results: Spread of activation was studied in infarcted papillary muscles from hearts of patients who underwent heart transplantation because of infarction. Recordings were carried out on 10 papillary muscles that were superfused in a tissue bath. High-resolution mapping was performed in areas revealing slow conduction. Activation delay between sites perpendicular to the fiber direction and 1.4 mm apart could be as long as 45 milliseconds. Analysis of activation times revealed that activation spread in tracts parallel to the fiber direction. Conduction velocity in the tracts was between 0.6 and 1 m/s. Although tracts were separated from each other over distances up to 8 mm, they often connected with each other at one or more sites, forming a complex network of connected tracts. In this network, wave fronts could travel perpendicular to the fiber direction. Separation of tracts was due to collagenous septa. At sites where tracts were interconnected, the collagenous barriers were interrupted., Conclusions: Slow conduction perpendicular to the fiber direction in infarcted myocardial tissue is caused by a "zigzag" course of activation at high speed. Activation proceeds along pathways lengthened by branching and merging bundles of surviving myocytes ensheathed by collagenous septa.