[Resynchronization therapy for heart insufficiency].
Explore the source record for details and available documents.
Cardiac Pacing, Artificial↗
Biomedical subjects
C Butter
Publications and source records attributed to C Butter.
Transradial unprotected left main coronary stenting supported by percutaneous Impella Recover LP 2.5 assist device.
Percutaneous coronary intervention (PCI) has been increasingly applied to patients with severely depressed left ventricular function and complex coronary lesions. The availability of hemodynamic support devices offers a promising option to reduce PCI-related complications in high-risk procedures. We report the case of a 79-year-old man who suffered from unstable angina. The coronary angiogram revealed multivessel disease including a significant distal left main (LM) stenosis. Additionally, the patient had a history of chronic lymphatic leukemia with immune hemolysis. Therefore, the patient was considered to be at exceptionally high mortality risk in case of cardiac surgery. We decided to perform a percutaneous revascularization of the LM supported by the Impella Recover LP 2.5 assist device. This case report discusses the principles of indications, technique and complications of this new addition to interventional cardiology.
Aged↗
[Cardiac resynchronization therapy for heart failure - from experimental pacing to evidence-based therapy].
Within the last decade, cardiac resynchronization therapy (CRT) has become an evidence-based cornerstone for a subset of patients with chronic heart failure. For those, who suffer from ischemic or non-ischemic cardiomyopathies at NYHA III or IV, have sinus rhythm, a left bundle branch block and a left ventricular ejection fraction below 35%, CRT has evolved as an important treatment option with promising results. Numerous studies have shown that in these patients pacemaker-mediated correction of intra- and interventicular conduction disturbances can improve not only clinical symptoms, exercise tolerance and the frequency of hospitalizations, but even more important the overall mortality. These clinical results are due to several functional aspects. In the failing heart characteristic intra- and interventricular alterations in electrical conduction result in mechanical asynchrony that leads to an abnormal contraction of the left ventricle with delayed activation of the lateral wall, a paradoxical septal movement, a reduced diastolic filling and a mitral regurgitation due to dyssynchrony of papillary muscle activation. It is conceivable that these functional changes have fatal consequences for the failing heart. AV-optimized left- or biventricular stimulation by modern pacemakers can correct the pathological dyssynchrony, thereby improving cardiac function and clinical outcome in these patients. Although tremendous progress in cardiac resynchronization therapy has been made during the last decade, a couple of questions still need to be resolved. Critical issues are the identification of patients, who will predictably benefit from CRT, the value of CRT-pacemakers versus CRT-ICDs, and the usefullness of CRT in patients with atrial fibrillation.
Cardiac Pacing, Artificial↗
[From guiding catheter to coronary sinus lead].
Biventricular pacing system implantation is a challenging procedure. The first-choice technique to initiate left ventricular pacing consists of a transvenous approach via the coronary sinus (CS) tributaries. Different techniques to achieve CS access using dedicated guiding catheters and left ventricular leads are described. New developments in catheter and lead technology are presented. The most common procedure-related complications are reported.
Cardiac Catheterization↗
[Three-dimensional vectorcardiography to predict CRT-responder].
Cardiac resynchronization therapy (CRT) is an accepted treatment for congestive heart failure (NYHA III-IV), but a substantial number of patients show no response to therapy. LBB, QRS width and echocardiographic measurements are parameters for indication, but they are not valid to predict hemodynamic response. A new method based on vector ECG analysis can deliver additional information, such as: parts or areas with late excitation, and with slow or fast depolarization speed. Electrical excitation is a prerequisite for contraction; this leads to the hypothesis that areas with late electrical activation will contract later. Algorithms for analysis of the vector ECG (determination of the vector -- time, area and speed) may help to identify responders and non-responders.
Arrhythmias, Cardiac↗
[Functional capacity as a criterion for patient selection--too poor or too good for CRT?].
The article analyses the status of functional tests used in patient selection for cardiac resynchronization therapy (CRT). Based on published randomized trials, the NYHA classification, the quality of life score, the 6-minute walk and the cardio-pulmonary exercise test (CPX) are reviewed. The NYHA classification is a weak and unspecific test and should be used only as a basic consideration in patient selection. The 6-minute walk test shows a wide spread of values and high dependency on patients' motivation. Patients' functional capacity is measured most objectively by the CPX test, which additionally stratifies prognosis. We conclude that functional capacity is an important criterion in patient selection for CRT. However, primary functional status is of minor importance in estimating the expected functional benefit since multiple factors influence the success of CRT.
Arrhythmias, Cardiac↗
[Is standard-echocardiography sufficient for identification of responders?].
During recent years cardiac re-synchronization has become an important tool in the treatment of patients with signs and symptoms of heart failure and de-synchronized contraction of the heart. This article describes the pathophysiological basis of de-synchronized contraction due to left bundle branch block and the use of conventional echocardiography to unmask whether the electrical abnormality is accompanied by an asynchronous contraction in the individual patient. The altered contraction in the de-synchronized heart is analysed on different levels: atrioventricular dyssynchrony describes the disturbed mechanical coupling of the ventricles and atria, interventricular dyssynchrony describes the disturbed mechanical coupling of the left and right ventricle, and intraventricular dyssynchrony describes the uncoordinated contraction of the left ventricle. Since tissue Doppler imaging is implemented only in the top level echo machines of the respective manufacturers, this article uses parameters derived from standard echo techniques to analyse the different aspects of dyssynchrony.
Arrhythmias, Cardiac↗
[Indication for cardiac resynchronization therapy: Consensus 2005].
The indication for cardiac resynchronization therapy (CRT) using biventricular pacing or ICD systems has to be highly differentiated to optimize the proportion of patients who derive significant symptomatic benefit from this therapy, on the one hand, and to avoid this invasive treatment in patients with a low probability of clinical success of CRT, on the other hand. As a consensus in 2005, it can be put forward that there is sufficient evidence for an indication for CRT from clinical studies for the following characteristics: 1) Heart failure in NYHA functional class III or IV (if cardiac recompensation to class III is at least temporarily successful), 2) left ventricular ejection fraction < or =35%, 3) QRS duration >130 ms, particularly if left bundle branch block is present, 4) sinus rhythm. In addition, available data also suggest an indication for CRT in patients with atrial fibrillation if the other criteria listed above are met. The indication for CRT is unclear in patients with other intraventricular conduction delay (particularly right bundle branch block) while patients with left bundle branch block and a QRS duration of 120-130 ms seem to benefit if echocardiographic criteria demonstrate ventricular dyssynchrony. Since a multiplicity of echocardiographic criteria of ventricular dyssynchrony exists which is neither standardized nor evaluated in large-scale randomized trials, ventricular dyssynchrony on echocardiography alone cannot be regarded as an established indication for CRT without a QRS complex > or =120 ms. Similarly, whether heart failure in functional state NYHA II should be regarded as a CRT indication is currently being investigated in the randomized RAFT and MADIT-CRT trials.
Arrhythmias, Cardiac↗
Successful cardiac resynchronization therapy in a 9-year-old boy with dilated cardiomyopathy.
Despite increasing clinical impact of cardiac resynchronization therapy (CRT) with av-synchronous biventricular pacing in adults with dilated cardiomyopathy (DCMP), an ejection fraction (EF) of less than 35% and left bundle branch block (LBBB), there is still only little experience in children. We report on a 9-year-old boy with histologically proven DCMP and LBBB who had fulfilled the criteria for heart transplantation (HTX) after cardiac decompensation including catecholamine therapy. A transvenous CRT pacing system was implanted without technical difficulties. The healing process was uneventful. With optimized AV-interval invasive evaluation during implantation indicated a 16% pulse pressure increase and a 63% augmentation of LV dp/dt by pacing the LV 20 ms prior to the RV. Tissue Doppler imaging demonstrated complete LV resynchronization. Physical capacity increased and HTX could be delayed.
Bundle-Branch Block↗
[Effect of cardiac resynchronization therapy (CRT) on exercise tolerance, functional capacity and quality of life in patients with congestive heart failure].
This review article summarizes the effect of cardiac resynchronization therapy (CRT) on exercise tolerance, functional capacity and quality of life, as it has been shown in previous randomized controlled trials. Based on these data we carefully have to reconsider the initial goals of this therapy. An early prophylactic implantation is not justified today. Especially patient selection has to be performed with more care in the future using new methods for detection of cardiac asynchrony to avoid a mismatch between implant numbers and real functional benefit.
Cardiac Pacing, Artificial↗
Orthotopic heart transplantation with concurrent coronary artery bypass grafting or previous stent implantation.
We describe three cases of donor hearts with preexisting coronary artery disease already diagnosed prior to transplantation: two were treated by coronary artery bypass grafting during the transplant procedure and one by angioplasty with stenting during the donor screening angiography. All three donor organs would otherwise have been rejected, depriving potential recipients of organ transplantation. All patients had an uneventful post-operative course with follow-up completed 22, 40 and 43 months after orthotopic transplantation showing patency of the stent and bypass grafts in the early (1 and 9 months) and late (22, 24 and 37 months) coronary angiography. Our results suggest that in this era of acute organ shortage donor hearts requiring bypass or stenting, which form a small but significant donor subgroup, can be used effectively and safely when matched to the recipients' age and medical condition.
Aged↗
Study of host-pathogen interactions to identify sustainable vaccine strategies to Marek's disease.
Marek's disease virus is a highly cell-associated, lymphotropic alpha-herpesvirus that causes paralysis and neoplastic disease in chickens. The disease has been contained by vaccination with attenuated viruses and provides the first evidence for a malignant cancer being controlled by an antiviral vaccine. Marek's disease pathogenesis is complex, involving cytolytic and latent infection of lymphoid cells and oncogenic transformation of CD4+ T cells in susceptible chickens. Innate and adaptive immune responses develop in response to infection, but infection of lymphocytes results in immunosuppressive effects. The remarkable ability of MDV to escape immune responses by interacting with, and down-regulating, some key aspects of the immune system will be discussed in the context of genetic resistance. Resistance conferred by vaccination and the implications of targeting replicative stages of the virus will also be examined.
Animals↗
Determinants of the quality of life (QoL) in patients with an implantable cardioverter/defibrillator (ICD).
OBJECTIVES: In high-risk cardiac patients the treatment of life-threatening arrhythmias with an implantable cardioverter/defibrillator (ICD) extends survival. Other important outcome criteria are treatment side effects especially the quality of life (QoL). Knowledge of the variables that influence QoL is important for therapy decisions in ICD patients. METHODS: Ninety-three ICD patients evaluated their QoL by the SF-36 after 1-6 years of ICD implantation. The QoL was studied in relation to cardiac function (severity of heart failure, ejection fraction), treatment course (number of shocks), coping styles and psychiatric syndromes. RESULTS: About 30% of the somatic QoL (physical role function, pain) is determined by the patients' somatization tendency, i.e. the extent to which they suffer from non-specific symptoms (sweating, weakness in the legs, nausea). The severity of heart failure had little influence on the physical QoL. The emotional QoL is primarily determined by phobic anxiety of ICD patients. CONCLUSIONS: Psychiatric symptoms are the most important factors to determine the QoL in ICD patients. Behavioural treatment procedures of phobic anxieties and somatization could improve QoL in ICD patients.
Adaptation, Psychological↗
Protection from infectious bursal disease virus (IBDV)-induced immunosuppression by immunization with a fowlpox recombinant containing IBDV-VP2.
Immunosuppression resulting from infectious bursal disease virus (IBDV) infection has critical health and welfare implications for birds, yet it is incompletely understood and largely overlooked as a measure of vaccine efficacy. The ability of a fowlpoxvirus recombinant (fpIBD1) containing the VP2 protein of IBDV to protect against IBDV-induced immunosuppression was investigated by measuring the convalescent chicken's ability to mount antibody responses to IBDV infection, and to inactivated IBDV and salmonella vaccines. An immunoglobulin (Ig)M response, but no IgG response, occurred after IBDV infection. Uninfected chickens produced a sustained IgM response and some IgG response to inactivated IBDV vaccine, while in previously infected birds only a transient IgM response was detected. A moderate suppression of the response to a commercial salmonella vaccine was evident after IBDV infection, which was largely prevented by immunization with fpIBD1. These results indicate that measurement of immunosuppression could be a useful strategy for assessing the efficacy of vaccines to protect against the consequences of IBDV infection.
Animals↗
Effect of resynchronization therapy stimulation site on the systolic function of heart failure patients.
BACKGROUND: Cardiac resynchronization therapy (CRT) improves systolic function in heart failure patients with ventricular conduction delay by stimulating the left ventricle (LV) or both ventricles (biventricular, BV). Optimal LV site selection is of major clinical interest for CRT device implantation; however, the dependence of hemodynamics on LV stimulation site has not been established. Thus, the objective of this study was to compare the hemodynamic response to CRT for 2 LV coronary vein sites: the free wall and anterior wall. Methods and Results- A total of 30 patients (mean NYHA class, 2.7; mean QRS interval, 152 ms; mean PR interval, 194 ms) enrolled in the PATH-CHF-II trial were studied. CRT was administered with LV and BV stimulation in VDD mode at 4 AV delays. LV stimulation was at the lateral free wall or anterior wall, whereas right ventricular stimulation was fixed near the apex. LV+dP/dt(max) and aortic pulse pressure changes from baseline during CRT were compared for LV sites. Free wall sites with LV and BV stimulation yielded significantly larger LV+dP/dt(max) (14% versus 6%, P<0.001 for LV; 12% versus 5%, P<0.001 for BV) and pulse pressure (8% versus 4%, P<0.001 for LV; 9% versus 5%, P<0.001 for BV) compared with anterior sites. In one third of patients, CRT at free wall sites increased LV+dP/dt(max), whereas it decreased at anterior sites over most AV delays. CONCLUSION: CRT with LV free wall stimulation produced significantly better LV systolic performance compared with anterior stimulation. Further studies are warranted to prove the clinical superiority of the LV free wall as a site for long-term CRT.
Aged↗
Transvenous biventricular defibrillation halves energy requirements in patients.
BACKGROUND: Defibrillation thresholds (DFT) with standard implantable cardioverter-defibrillator leads in the right ventricle (RV) may be determined by weak shock field intensity in the myocardium of the left ventricle (LV). Adding a shocking electrode in a coronary vein on the middle of the LV free wall, thereby establishing biventricular defibrillation, substantially reduced defibrillation requirements in animals. We investigated the feasibility of this approach in 24 patients receiving an implantable cardioverter-defibrillator using a prototype over-the-wire temporary LV defibrillation lead. METHODS AND RESULTS: The LV lead was inserted through the coronary sinus, using a guide catheter and guidewire, into a posterior or lateral coronary vein whose location was determined by retrograde venography. Paired DFT testing compared a standard system (RV to superior vena cava plus can emulator [SVC+Can], 60% tilt biphasic shock) to a system including the LV lead. The biventricular system was tested with a dual-shock waveform (20% tilt monophasic shock from LV-->SVC+Can, then 60% tilt biphasic shock from RV-->SVC+Can). Twenty patients completed DFT testing. Venography and LV lead insertion time was 46+/-40 minutes. The biventricular system reduced mean DFT by 45% (8.9+/-1.1 J versus 4.9+/-0.5 J, P<0.001). Twelve patients (60%) had a standard system DFT >/=8 J, and the biventricular system gave a lower DFT in all patients. There were no adverse events related to the use of the LV lead, which was removed after testing. CONCLUSIONS: Internal defibrillation using a transvenously inserted LV lead is feasible, produces significantly lower DFTs, and seems safe under the conditions tested. Biventricular defibrillation may be a useful option for reducing DFTs or could be added to an LV pacing lead for heart failure.
Coronary Angiography↗
Investigation of coronary venous anatomy by retrograde venography in patients with malignant ventricular tachycardia.
BACKGROUND: The coronary venous system is increasingly used for left ventricular or biventricular pacing in patients with severe heart failure. The present study investigated the structure of the coronary veins in patients presenting with structural heart disease and malignant ventricular tachyarrhythmias. The availability of veins for possible lead placement was assessed. METHODS AND RESULTS: The number, relative size, and location of coronary veins were evaluated by retrograde venography in 129 patients undergoing cardioverter-defibrillator implantation. Detailed x-ray image analysis was performed in 86 patients, for whom optimal coronary sinus occlusion and vein visualization was achieved. The anterior interventricular vein and the middle cardiac vein were visible in 85 (99%) of 86 patients and in 86 (100%) of 86 patients, respectively. Between these 2 veins, at least 1 additional prominent vein was visible in 85 (99%) of 86 patients. Just 1 vein was present in 44 (51%) of 86 patients. Two veins were observed in 40 (46%) of 86 patients, and >2 veins were visualized in 2 (2%) of 86 patients. Venous anatomy allowed positioning of a 0.014-in guidewire in a coronary vein in 115 (93%) of 124 patients. CONCLUSIONS: The presence, diameter, angulation, and tortuosity of veins as visualized by retrograde venography determine their acceptability for the placement of a lead in a predetermined location. Despite the considerable variability of the coronary venous system among patients, a lateral vessel for lead introduction was available in 82%, and a posterior or lateral vessel was available in 99% of individuals within a patient population that could potentially benefit from a lead on the left ventricle.
Aged↗
Clinical validation of new pacing-sensing configurations for atrial automatic capture verification in pacemakers.
INTRODUCTION: This study evaluated an atrial automatic capture verification scheme based on atrial evoked response (AER). Atrial pacing was between Atip and Can (Atip-Can) using different coupling capacitances (CCs). Independent pairs of sensing electrodes between Aring and Vtip (Aring-Vtip) or between Aring and a separate indifferent electrode (Aring-Indiff) were used to reduce pacing-induced afterpotentials. METHODS AND RESULTS: A custom-made external pacing system was used to perform automatic step-up and step-down pacing (0.1 to 7.1 V at 0.5 msec, step size of 0.1 V) using different CCs (2 or 15 microF). Intracardiac signals from Aring-Indiff and Aring-Vtip were independently recorded and analyzed both in real time and off-line to detect AER. Every paced beat also was visually inspected and compared with surface ECG to verify the captures. With the intracardiac signals properly filtered, AER detection was based on the signal within a window of 12 to 65 msec after the stimulus. Data from 27 patients (4 chronic and 23 acute implantations; age 65.6+/-13.9 years) were analyzed. Bipolar atrial lead measurements using a standard pacing system analyzer were as follows (mean +/- SD): impedance 695+/-227 ohms, P wave amplitude 4.2+/-2.3 mV, slew rate 1.1+/-0.9 V/sec, and pacing threshold at 0.5 msec 1.0+/-0.5 V. The results with CC = 2 microF showed that of 9,500 atrial paced beats, correct capture verification rates were 99.8% (Aring-Indiff) and 99.4% (Aring-Vtip). Similar results were achieved with CC = 15 microF (99.7% and 99.5%, respectively). CONCLUSION: AER can be reliably detected using independent pacing (Atip-Can) and sensing (Aring-Vtip or Aring-Indiff) electrodes. Therefore, atrial automatic capture verification by AER detection is feasible.
Adult↗