The coronary-subclavian-vertebral steal syndrome (CSVSS).

OBJECTIVE: Reverse flow in the internal thoracic artery (ITA) after coronary bypass surgery due to an occlusion or severe stenosis of the subclavian artery is a rare situation. Symptoms can be recurrent and intermittent angina pectoris in the case of a coronary-subclavian steal (CSSS) or-in addition with cerebral symptoms-in the case of a coronary-subclavian-vertebral steal syndrome (CSVSS). METHOD: We describe the cases of four patients with recurrent angina pectoris 5, 11, and 14 years as well as directly after coronary bypass surgery with LITA grafts to LAD. In two patients there was the additional aspect of vertebral steal symptoms with dizziness and intermittent drop attacks. RESULTS: A PTA of the subclavian occlusions in three cases was not feasible, so that three patients were operated on by extrathoracal approach and carotido-subclavian bypass (CSB) in two cases, and local thrombendarteriectomy of the subclavian and vertebral artery (TEA)+ -patchplasty in one case. Patient 4 was treated by PTA and stent placement into the subclavian artery. Antegrade flow in all four LITAs could be achieved resulting in immediate relief from angina pectoris and cerebral symptoms. Patients 1 and 3 showed no further symptoms with equal BP of the upper extremities and anterograde flow in the LITA grafts and vertebral artery at 10-month follow-up. Patient 2 unfortunately died from an unrelated cause (asthmatic state) 4 months after the operation despite an uneventful recovery. CONCLUSION: The occurrence of a CSSS or CSVSS after coronary bypass surgery with retrograde flow in the ITA graft (as described in our four patients) is a rare, but potentially hazardous, situation. If the subclavian occlusion is not amenable to endovascular strategies, the extrathoracal approach by CSB or local TEA and patchplasty provides an excellent means with good midterm and long-term results.

[Aneurysm of the subclavian artery after operatively corrected coarctation of the aorta: 20 years of follow-up and review of the current literature]. / Aneurysma der Arteria subclavia nach Korrektur einer Aortenisthmusstenose. 20-jähriger Langzeitverlauf und Literaturübersicht.

We report of long-term follow-up of a combined fusiform aneurysm of the right subclavian artery extending to the thyreocervical trunk (3.2 x 2.8 x 2.2 cm (width x height x depth)) in a 33-year old patient. As a newborn, the clinical diagnosis of an aortic isthmus stenosis was made without need for intervention at this stage. Further development of the child remained unremarkable until the age of eleven years when he experienced dizziness after sporting activities. Due to clinically proven progress, cardiac catheterization was performed and confirmed the initial diagnosis of a juxtaductale stenosis of the aortic isthmus, which was operated thereafter with an end-to-end anastomosis. Furthermore, an aneurysm of the right subclavian artery was revealed. Since then, non-invasive routine follow-up showed no significant worsening of this aneurysm, which extends to the thyreocervical trunk. The patient has been event free and completely asymptomatic. This case report illustrates the more than twenty years of follow-up of an asymptomatic combined fusiform aneurysm of the subclavian artery and thyreocervical trunk and provides a review of the literature on this topic.

Congenital aortic regurgitation due to absent aortic cusps and high-degree mitral stenosis.

Congenital absence of aortic cusps leads to severe aortic regurgitation. We present a newborn with this rare entity with extreme mitral stenosis. Hemodynamic features were those of hypoplastic left heart syndrome. Surgical management consisted of initial modified Norwood procedure followed by orthotopic heart transplantation.

Uniform long-term gene expression using adeno-associated virus (AAV) by ex vivo recirculation in rat-cardiac isografts.

BACKGROUND: Gene therapy in cardiovascular disease promises to be of great impact. The ideal vector for the therapeutic gene transfection remains to be determined. The aim of the present study was to investigate the efficacy of gene transfer using adeno-associated virus vectors carrying the lacZ-reporter gene (AAV-lacZ) in a previously described coronary recirculation model. METHODS: Beating Lewis rat hearts perfused with oxygenated Krebs-Henseleit solution were harvested, after which an atrial septal defect (ASD) was created. All vessels were tied, and AAV-lacZ was injected into the aortic root. The solution was recirculated through the ASD to the left side of the heart and pumped back to the coronary arteries by the left ventricle. Incubation was allowed for 20 min at 15 degrees C, and the hearts were subsequently transplanted heterotopically in syngeneic rats. Three increasing doses (109, 1,010, 1,011 e. u.) of AAV-lacZ virus vectors were used to study the rate of gene transfer. All hearts were harvested after 7-60 days and evaluated histologically for expression of the lacZ-gene. RESULTS: Dose-dependent gene transfer was observed. Even after 60 days, there was no obvious decline in gene expression. CONCLUSION: Adeno-associated virus vectors offer effective and uniform gene transfer in the myocardium after transcoronary injection and recirculation. Due to the lack of immune response previously described, no decrease in gene expression can be observed up to 60 days after injection.

Mitral valve surgery in patients with poor left ventricular function.

BACKGROUND: Mitral valve surgery for the correction of secondary mitral valve regurgitation (MR) in cardiomyopathy is associated with a poor outcome. Numerous studies have identified a severe left ventricular dysfunction as an indicator for a poor prognosis. The aim of the study was to asses the follow-up after mitral valve surgery and severe left ventricular dysfunction. METHODS: Between 1994 and 2000, 31 patients with mitral regurgitation and a left ventricular ejection fraction of below thirty percent undergoing isolated repair (n = 16) or replacement (n = 15) were investigated. All patients received maximal drug therapy. Twenty-one patients were New York Heart Association (NYHA) class III and 10 were class IV. Follow-up with echocardiography, ECG, and chest x-ray was performed in 87 % of the survivors. The mean duration of follow-up was 39 +/- 16 months. RESULTS: The mean duration of ICU and hospital stay was 3.6 +/- 2.1 days and 8.1 +/- 5.4 days, respectively. The 1-, 2-, and 5-year survival rates were 91 %, 84 %, and 77 %, respectively. NYHA class improved from 3.3 +/- 0.8 to 2.1 +/- 0.7 at follow-up (p < 0.01). The ejection fraction improved from 23.1 +/- 6.6 % to 36 +/- 6.8 % at follow-up (p < 0.02). Freedom from readmission for heart failure was 85 %, 79 %, and 68 % at 1-, 2-, and 5 years, respectively. CONCLUSIONS: Mitral valve surgery improves left ventricular function and reduces heart failure severity in patients with MR and cardiomyopathy. High-risk mitral valve surgery may be an alternative to heart transplantation in selected patients.

Successful cardiac transplantation after Novacor implantation in a HIT II-patient using heparin.

The anticoagulative management of patients tested positive for heparin-induced thrombocytopenia type II (HIT II) and requiring cardiac surgery has been difficult until now. A special challenge arises, when left ventricular assist devices have to be implanted for bridging to cardiac transplantation. We report on the anticoagulative management of such a patient, based on the consideration of HIT II-pathophysiology and using heparin for Novacor LVAD implantation and cardiac transplantation.

Does a suitable animal model for research on partial left ventriculectomy exist? Animal models for PLV.

Partial left ventriculectomy is a new surgical option quickly introduced into clinical use worldwide for treating end-stage heart failure in patients with dilated cardiomyopathy. Due to the overwhelming success of this new kind of surgical treatment for dilated cardiomyopathy, experimental research on the physiological and pathophysiological basis was initially not performed. Now, demands for an appropriate animal model have arisen more and more since the outcome of patients treated by partial left ventriculectomy has differed considerably. This review summarizes available experimental models for heart failure in large animals, and discusses their suitability for research on partial left ventriculectomy.

Defibrillation efficacy comparing a subcutaneous array electrode versus an "active can" implantable cardioverter defibrillator and a subcutaneous array electrode in addition to an "active can" implantable cardioverter defibrillator: results from active can versus array trials I and II.

INTRODUCTION: Placement of implantable cardioverter defibrillators (ICDs) has been simplified by using the shell of a pectorally implanted ICD as a defibrillation electrode in combination with an endocardial right ventricular defibrillation lead. However, a sufficiently low defibrillation threshold (DFT) cannot be obtained in a few patients. Therefore, alternative approaches were systematically tested in the Active Can versus Array Trial (ACAT). METHODS AND RESULTS: In the first of two prospective randomized studies, the DFT of a subcutaneous left dorsolateral array anode introduced from a pectoral incision was compared to that of a standard active can anode in 68 patients. Intraoperatively, the DFT was determined twice in each patient using either the active can or, in patients with a subcutaneous array lead, once with all three fingers and once omitting the middle finger of the array. The second prospective randomized study included 40 patients. DFT also was determined twice in each patient using an active can in a left pectoral position as anode alone and combined with a left dorsolateral array electrode with two fingers. In ACAT I, stored energy at DFT decreased from 13.1+/-7.7 J (active can) to 9.6+/-6.1 J (three-finger array lead) (P = 0.04), impedance decreased from 53+/-8 ohms to 40+/-6 ohms (P < 0.0001). Omitting the middle finger of the array lead, stored energy at DFT increased by 0.9 J (P = 0.47) and impedance by 2 ohm (P < 0.0001). In ACAT II, DFT and impedance using an active can device were significantly lower when a two-finger array lead was added that decreased stored energy at DFT from 10.1+/-5.2 J to 6.9+/-3.9 J (P = 0.001) and impedance from 56+/-5 1 to 42+/-5 l (P < 0.0001). CONCLUSION: In combination with a right ventricular defibrillation electrode, a left pectoral subcutaneous array lead improves defibrillation efficacy if used instead of, or in addition to, a left pectoral active can ICD device. Implantation of the array lead can be simplified by using two instead of three fingers, without a significant loss of defibrillation efficacy.

Implantation of a dual chamber pacing and sensing single pass defibrillation lead.

Dual-chamber ICDs are increasingly used to avoid inappropriate shocks due to supraventricular tachycardias. Additionally, many ICD patients will probably benefit from dual chamber pacing. The purpose of this pilot study was to evaluate the intraoperative performance and short-term follow-up of an innovative single pass right ventricular defibrillation lead capable of bipolar sensing and pacing in the right atrium and ventricle. Implantation of this single pass right ventricular defibrillation lead was successful in all 13 patients (age 63 +/- 8 years; LVEF 0.44 +/- 0.16; New York Heart Association [NYHA] 2.4 +/- 0.4, previous open heart surgery in all patients). The operation time was 79 +/- 29 minutes, the fluoroscopy time 4.7 +/- 3.1 minutes. No perioperative complications occurred. The intraoperative atrial sensing was 1.7 +/- 0.5 mV, the atrial pacing threshold product was 0.20 +/- 0.14 V/ms (range 0.03-0.50 V/ms). The defibrillation threshold was 8.8 +/- 2.7 J. At prehospital discharge and at 1-month and 3-month follow-up, atrial sensing was 1.9 +/- 0.9, 2.1 +/- 0.5, and 2.7 +/- 0.6 mV, respectively, (P = NS, P < 0.05, P < 0.05 to implant, respectively), the mean atrial threshold product 0.79, 1.65, and 1.29 V/ms, respectively. In two patients, an intermittent exit block occurred in different body postures. All spontaneous and induced ventricular arrhythmias were detected and terminated appropriately. Thus, in a highly selected patient group, atrial and ventricular sensing and pacing with a single lead is possible under consideration of an atrial pacing dysfunction in 17% of patients.

Primary tissue failure of bioprostheses: new evidence from in vitro tests.

BACKGROUND: Primary tissue failure, which is mainly caused by calcification, is still the limiting factor in the long-term outcome of heart valve bioprostheses. Even though the precise nature of this process is not fully understood, in vitro tests have been developed to reproduce and predict calcification for individual bioprostheses. METHODS: In vitro calcification testing was performed by using an accelerated pulsatile valve tester which was adapted for testing stented as well as stentless bioprostheses with physiological fluid dynamics. A total of 84 bioprostheses (porcine, pericardial and stentless porcine of different manufacturers) were cyclically loaded at a test rate of 300/min at 37 degrees C within a rapid calcification fluid with CaxP = 130(mg/dl)2 at pH 7.4. Calcification was assessed by microradiography after 12 x 10(6) cycles. In a previous step, holographic interferometry was performed to identify irregularities of valve leaflets in order to predict later calcification. Selected specimens of calcified bioprostheses underwent histology, transmission (TEM) and scanning (SEM) electron microscopy. Tissue mineralization was investigated by coupling SEM, electron microprobe analysis (EMPA) and X-ray powder diffraction (XRPD) methods. RESULTS: For all tested bioprostheses, a significant calcification was achieved within 4 to 6 weeks of ongoing testing, and the degree of calcification increased with time. A significant correlation between calcification and leaflet irregularities (detected by holographic interferometry) was found (r = 0.80, p = 0.001). Calcification varied between individual bioprostheses, and significant differences were detected for different groups (calculated as percentage of total leaflet area, mean +/- SD): porcine stented (37.3 +/- 12.0%), bovine stented (23.0 +/- 8.9%), porcine stentless (16.2 +/- 7.6%). Histological and ultrastructural investigation showed intrinsic calcification involving both the spongiosa and fibrosa with collagen fibrils, interfibrillar spaces and cells as early sites of calcification. There was clear evidence of apatite crystallization, and observations made with in vitro calcification were quite similar to those occurring with in vivo implanted bioprostheses. CONCLUSION: In vitro tests can reproduce intrinsic calcification of bioprostheses even in the absence of viable biologic host factors. Moreover, degree and sites of calcification have become predictable. This enables the development and evaluation of bioprostheses with reduction of animal experiments. From our results obtained with a broad range of available bioprostheses, stented bovine and stentless porcine valves seem to be superior to conventional stented porcine bioprostheses with regard to leaflet calcification.

Nonthoracotomy implantable cardioverter defibrillator placement in children: use of subcutaneous array leads and abdominally placed implantable cardioverter defibrillators in children.

INTRODUCTION: The need to access the right ventricle might preclude transvenous placement of a defibrillation lead at implantable cardioverter defibrillator (ICD) placement, especially in small children or children with complex congenital heart defects. We investigated a subcutaneous array lead in addition to an abdominally placed "active can" ICD device in two children to avoid a thoracotomy. METHODS AND RESULTS: The first child (age 12 years, 138 cm, 41 kg) had transposition of the great arteries with a subsequent surgical intra-atrial correction by the Mustard technique. The second child (age 14 years, 161 cm, 54 kg) had a single atrium and a single ventricle, d-transposition of the aorta, and atresia of the main pulmonary artery with a surgical anastomosis between the aorta and the right pulmonary artery by the Cooley technique. The defibrillation threshold was 18 J and <20 J at initial implantation and at generator replacement in the first patient and 20 J in the second patient. During follow-up of 6 years and 1 month, respectively, no ICD-related complications occurred. CONCLUSION: In children in whom endocardial, right ventricular placement of a defibrillation lead is precluded, defibrillation is possible and safe between an abdominally placed "active can" ICD device and a subcutaneous array lead. This approach may avoid a thoracotomy in children with no possibility for transvenous ICD placement.

Noncardiac surgery in patients with left ventricular assist devices.

BACKGROUND: Noncardiac surgery, especially abdominal surgical procedures in patients with long-term mechanical circulatory support and strong anticoagulation, is difficult. METHODS: We report on 14 patients (aged 44 +/- 15 years) with a portable Novacor or HeartMate system, who underwent noncardiac surgical procedures while being supported by the device. RESULTS: The patients underwent 20 procedures for noncardiac reasons; most had an intestinal operation or cholecystectomy. Half of the procedures were performed within 30 days after placement of the device (mean interval, 53 +/- 57 days), only 6 interventions were necessary after 100 days of mechanical support. Complications occurred in 8 patients (57%), 5 of whom had undergone cholecystectomy and had unacceptably high sanguineous drainage losses. CONCLUSIONS: An elective surgical procedure can be performed with an acceptable risk if the operation is carefully managed. Postponing resumption of full anticoagulation is advisable as it may reduce bleeding complications without apparently increasing the risk for thromboembolism. Emergency interventions remain a difficult task.

Signal characteristics of multichannel epicardial electrograms in chronic ischaemic and scarred myocardium: electromechanical mismatch indicates viability in regions of myocardial dysfunction.

BACKGROUND: To predict the outcome after myocardial revascularisation, a clear separation between hibernation and/or repetitive stunning on the one hand and myocardial scarring on the other hand is of importance. METHODS AND RESULTS: A total of 44 patients was included in this study. In 35 patients with chronic myocardial ischaemia and an indication for coronary bypass-surgery, epicardial mapping of local activation was performed. Nine patients with LV aneurysm and an indication for antitachycardia surgery were also included. For simultaneous recording of the local electrograms during sinus rhythm, a sock electrode with 102 bipolar leads was used. The regional myocardial contraction pattern was assessed from preoperative angiograms and regional myocardial metabolism (viability) from 18F-FDG PET, respectively. The results were projected on the grid of the intraoperative position of the sock electrode. This enabled regional comparison of electrogram characteristics to local contraction patterns and viability. For the characterisation of local electrograms, peak-to-peak amplitude and duration of activation were calculated using custom-made automated computer-algorithms. Dysfunctional but viable areas showed normal or almost normal electrographic signal characteristics. In contrast, dysfunctional and non-viable myocardium showed a distinct reduction of local amplitudes and prolongation of signal duration. These changes were even more intense in areas of LV aneurysms. CONCLUSIONS: In patients with chronic ischaemic myocardium, a mismatch between mechanical function and local electrogram characteristics was observed in areas with preserved metabolism. Thus, normal epicardial electrograms in regions of myocardial dysfunction may be an indicator for myocardial viability.